Orthopedic Ob Shoulder And Elb Review | Dr Hutaif Shoul -...

The patient has an intraarticular noncomminuted lateral process of the talus fracture that would be best treated with open reduction internal fixation.
Lateral process of the talus fractures occur commonly in snowboarders following a twisting injury while the foot is strapped to the board. Diagnosis is often missed and confused with a lateral ankle sprain. Close examination of plain films may show a lateral process of the talus fracture or CT scan may be warranted if radiographs are negative and suspicion is high. Once a lateral process of the talus fracture is identified, fracture comminution, displacement, and angulation determine if nonoperative treatment is possible. In cases of noncomminuted intraarticular fractures open reduction internal fixation is advised. In cases of comminuted intraarticular fractures that fail nonoperative management, fragment excision is indicated and is not felt to lead to ankle instability based on cadaveric testing.
von Knoch et al. followed 23 snowboarders with lateral process of the talus fractures treated operatively and nonoperatively. They found 65% of patients returned to preinjury level of sporting and 45% had radiographic evidence of arthritis. They concluded that outcomes are favorable following lateral process of the talus fractures given early identification and treatment.
Langer et al. studied 10 fresh frozen cadavers for instability following excision of a 1cm area of the lateral process of the talus. They found the mean increase in anterior tibial translation (AT), talar tilt (TT), medial talocalcaneal motion, and talocalcaneal tilt (TCT) were all less than the accepted cut-offs for ankle and subtalar instability. They conclude excision of a 1cm fragment of the lateral process of the talus leads to neither ankle or subtalar instability.
Berkowitz et al. reviewed the various tubercle and process fractures of the talus and calcaneus. They state when a fracture fragment is <1cm and <2mm displaced nonoperative treatment in a non-weight bearing short leg cast for 6 weeks is recommended. They recommend large noncomminuted intraarticular fractures be treated with open reduction internal fixation and comminuted intraarticular fractures be primarily excised. Chronic painful nonunions respond best to delayed surgical excision.
Figure A shows a mortise view of the ankle with evidence of a lateral process of the talus fracture. Figure B shows a coronal CT scan with a displaced noncomminuted intraarticular lateral process of the talus fracture.
Incorrect Answers:
Answer 1: The lateral process of the talus is the correct diagnosis but this fragment is amenable to open reduction internal fixation.
Answer 3 & 4: There is no radiographic evidence of an anterior process of the calcaneus fracture
Answer 5: A posterior process of the talus fracture would be seen on a lateral view of the ankle which is not seen.

The patient underwent an ACL reconstruction that has now failed. Based on his examination, he also has a posterolateral corner injury. Because this concomitant injury was not treated, the patient had undue strain on his graft, resulting in ultimate failure. Hamstring grafts are as effective as other graft types for ACL reconstruction. The medial meniscus provides secondary stabilization to the knee; however, this patient has a missed lateral ligamentous injury, and meniscus tears do not result in the development of a varus thrust. An unrecognized PCL tear likely results in mild-to-moderate medial and patellofemoral osteoarthritis without significant lateral laxity and thrust.
39

Tibial tubercle avulsion is an injury of the adolescent knee that most often occurs just before the end of growth. The fracture usually occurs with jumping, either at push-off or landing. This patient has a type III injury. In type III injuries, the articular surface is disrupted, and meniscal injury and compartment syndrome can occur. Open reduction is the treatment of choice, and anterior fasciotomy should be considered prophylactically at the time of surgery. Although the fracture heals with an anterior epiphysiodesis of the proximal tibia, little growth remains in this patient and no special handling of the physis is warranted.
REFERENCES: Ogden JA, Tross RB, Murphy MJ: Fractures of the tibial tuberosity in adolescents. J Bone Joint Surg Am 1980;62:205-215.
Pape JM, Goulet JA, Hensinger RN: Compartment syndrome complicating tibial tubercle avulsion. Clin Orthop 1993;295:201-204.

A lipoma in the foot frequently presents as a dorsal foot mass. The MRI appearance of the lesion is homogenous with density of subcutaneous fat on all sequences. There is no enhancement of the lesion with administration of contrast. The mass is consistent with a simple lipoma. Treatment for a simple lipoma is marginal excision. Amputation, radical excision, and adjuvant therapies are most appropriate for malignant tumors.

The central one third has been established as the watershed zone by angiographic studies, and has been borne out in clinical conditions involving the navicular, such as stress fractures and osteonecrosis. These findings account for the susceptibility to injury at this level.
REFERENCES: Nunley JA, Pfeffer GB, Sanders RW, et al (eds): Advanced Reconstruction: Foot and Ankle. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004,
pp 239-242.
Sarrafian SK: Anatomy of the Foot and Ankle. Philadelphia, PA, JB Lippincott, 1983,
pp 299-302.

A higher risk of nonunion and the need for prolonged immobilization is seen after nonsurgical management of proximal pole fractures of the scaphoid. Because of the relatively poor blood supply of the proximal pole, surgical treatment with a compression screw is advocated for fractures of the proximal third of the scaphoid.
REFERENCES: Clay NR, Dias JJ, Costigan PS, et al: Need the thumb be immobilized in scaphoid fractures? A randomised prospective trial. J Bone Joint Surg Br 1991;73:828-832.
Ring D, Jupiter JB, Herndon JH: Acute fractures of the scaphoid. J Am Acad Orthop Surg 2000;8:225-231.

In a retrospective review of 137 patients treated surgically and 153 patients treated nonsurgically for adult scoliosis, Bess and associates found that surgical treatment for patients younger than 50 years of age was driven by increased coronal plane deformity, and surgical treatment for older patients was mandated by pain and disability. They also concluded that age, comorbidities, and sagittal balance did not influence treatment decisions.
RECOMMENDED READINGS
[Bess S, Boachie-Adjei O, Burton D, Cunningham M, Shaffrey C, Shelokov A, Hostin R, Schwab F, Wood K, Akbarnia B; International Spine Study Group. Pain and disability determine treatment modality for older patients with adult scoliosis, while deformity guides treatment for younger patients. Spine (Phila Pa 1976). 2009 Sep 15;34(20):2186-90. PubMed PMID: 19752704.](http://www.ncbi.nlm.nih.gov/pubmed/19752704)[View ](http://www.ncbi.nlm.nih.gov/pubmed/19752704)[Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/19752704)
Anderson DG, Albert T, Tannoury C. Adult scoliosis. In: Spivak JM, Connolly PJ, eds. Orthopaedic Knowledge Update: Spine 3. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2006:331-338.

This patient has likely sustained an isolated PCL injury. The examination is consistent with a grade II injury to the PCL. In this scenario, the best initial option is nonsurgical treatment and return to play as symptoms subside and strength improves. Physical therapy with a focus on quadriceps strengthening and delayed PCL reconstruction is not the answer because this patient can likely be treated without surgery. The absence of valgus laxity and negative dial testing findings suggest that an injury to the posteromedial and posterolateral corners has not occurred. Initial nonsurgical treatment is indicated for this patient. If he completes rehabilitation and experiences persistent disability with anterior and/or medial knee discomfort or senses the knee is "loose," PCL reconstruction should be considered at that time.

The anteroposterior and lateral radiographs show thinned cortices and a gentle S-shaped curve of the tibia. The overall alignment of the tibia, as well as the physes, is normal. These are the radiographiCfeatures of osteogenesis imperfecta.
In osteogenesis imperfecta, the genetiCdefect involves type I collagen. Type I collagen is made up of two alpha-1 chains and one alpha-2 chain in a triple helix. Glycine is the smallest amino acid and is crucial for coiling of the triple helix. Mutations in the
glycine chain lead to severe forms of osteogenesis imperfecta. One should also remember the Silence classification:
Type Inheritance Sclera Severity
I AD Blue Mild form, normal teeth
II AR Blue Lethal form, die early
III AR Normal Severe, progressively deforming
IV AD Normal Moderately severe
Biphosphonate therapy can be used to slow bone remodeling and increase bone mass. With regard to the incorrect choices:
FGF receptor 3 is associated with achondroplasia. Fibrillin is associated with Marfan's syndrome.
Type II collagen is associated with spondyloepiphyseal dsyplasia.
Cartilage oligomeriCmatrix protein is associated with pseudoachondroplasia. Correct Answer: Type I collagen

The National Collegiate Athletic Association's (NCAA) 2011 revised health and safety guidelines regarding concussion management recommend no return to play on the same day of an injury. In particular, athletes sustaining a concussion should not return to play the same day as their injury. Before resuming exercise, athletes must be asymptomatic or returned to baseline symptoms at rest and have no
symptoms with cognitive effort. They must be off of medications that could mask or alter concussion symptoms. Neurocognitive testing can be a helpful tool in determining brain function even after all symptoms of concussion have resolved. With a comparison baseline test, this evaluation, in conjunction with a physician's examination, may reduce risk for second impact syndrome. The athlete's clinical neurologic examination findings (cognitive, cranial nerve, balance testing) must return to baseline before resuming exercise. Research has shown that among youth athletes, it may take longer for tested functions to return to baseline (compared with the recovery rate in adult athletes). Brain MRI scan has no role in evaluating athletes for return to play in this situation.

The lumbosacral plexus is formed from the lumbar and sacral roots that are redistributed into the obturator, femoral, and sciatic nerves. The obturator nerve is composed of the L1, L2, and L3 roots. The femoral nerve has contributions from the L3 and L4 roots. The sciatic nerve contains the L4, L5, S1, and lower sacral roots. Therefore, only the L4 root contributes to the femoral and sciatic (via the lumbosacral trunk) nerves, which allows it to innervate the quadriceps and the anterior tibialis muscles.
RECOMMENDED READINGS
32
1. Netter FH. The Ciba Collection of Medical Illustrations: The Musculoskeletal System, Part 1: Anatomy, Physiology and Metabolic Disorders. Summit, NJ: Ciba-Geigy; 1991:77-82.
2. [Samudrala S Department Of Neurosurgery University Of Southern California Medical School Los Angeles California And Department Of Neurosurgery University Of Florida Medical School Gainesville Florida, Khoo LT, Rhim SC, Fessler RG. Complications during anterior surgery of the lumbar spine: an anatomically based study and review. Neurosurg Focus. 1999 Dec 15;7(6):e9. PubMed PMID: 16918208. ](http://www.ncbi.nlm.nih.gov/pubmed/16918208)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/16918208)

Ankle arthritis is rarely idiopathic. In the United States, the most common source of ankle arthritis is following trauma, usually of a major nature. Repetitive ankle injury, particularly when associated with recurrent instability and a varus or cavus foot, will likely lead to the development of ankle arthritis. Patients should be counseled that recurrent instability of the ankle, particularly when osteophytes are already present, frequently leads to arthritis.

The best way to address varus malunion in talar neck fractures and maintain motion is by talar neck osteotomy. However, there is a further possible risk of talar avascular necrosis with this procedure. The other acceptable treatment is a triple arthrodesis, although this eliminates all hindfoot motion.

The use of locked nailing for the treatment of established nonunion of the humerus has produced poor results. Since humeral nailing has already failed, exchange humeral nailing without bone grafting has an even less change of success. To increase the likelihood of achieving bony union, the treatment of choice is removal of the humeral nail, dynamic compression plating, and bone grafting.
REFERENCES: Zuckerman J, Giordanno C, Rosen H: Treatment of humeral shaft non-unions, in Bigliani L (ed): Complications of shoulder surgery. Baltimore, MD, William & Wilkins, 1993, pp 173-190.
Jupiter JB: Complex non-union of the humeral diaphysis: Treatment with a medial approach,
an anterior plate, and a vascularized fibular graft. J Bone Joint Surg Am 1990;72:701-707.

Maintenance of adequate hydration is the single most important factor affecting athletic performance. While carbohydrate loading may be beneficial for some endurance athletes, the consumption of carbohydrates during exercise does not appear to be beneficial for athletes engaged in events that last less than 1 hour. In general, athletes consuming a balanced diet do not need electrolyte supplementation.
REFERENCES: Maughan RJ, Noakes TD: Fluid replacement and exercise stress: A brief review of studies on fluid replacement and some guidelines for the athlete. Sports Med 1991;12:16-31.
Barr SI, Costill DL, Fink WJ: Fluid replacement during prolonged exercise: Effects of water, saline, or no fluid. Med Sci Sports Exerc 1991;23:811-817.

C entral deficiencies allow a wide grasp, good release and pinch. These are also termed "cleft hand". The other conditions produce greater impairment.

The involved muscles have C 5, C 6 root innervations. Positive Tinelâs sign, functioning rhomboids and serratus anterior, and the absence of Hornerâs syndrome rule out a preganglionic lesion. The EMG finding confirms the clinical finding. Subclinical involvement of any other muscle is not shown. Neuropraxia usually recovers in 6 weeks and EMG shows fibrillation, which is inconsistent with neuropraxia. Brachial plexus neuritis, Parsonage-Turner syndrome, has an acute presentation following a painful episode involving the whole arm. There is significant history of a fall in this case.

The patient has exposed bone and tendon and a partial tendon injury. The remaining radial tendon is satisfactory and no tendon repair is required. The exposed bone and tendon necessitate vascularized tissue coverage. A reversed cross-finger flap from the ring finger is suitable for coverage of the dorsal surface of an adjacent digit.

DISCUSSION: Polyethylene wear is evident due to the superiorly eccentric position of the femoral head within the acetabulum. Despite proximal femoral osteolysis, the component appears well fixed, as does the acetabulum. The acetabular component appears to be well positioned. Therefore, an isolated synovectomy and polyethylene liner exchange is indicated. If the hip is stable, there is no need for more extensive revision work.

REFERENCE: Barrack RL, Booth RE Jr, Lonner JH, et al (eds): Orthopaedic Knowledge Update: Hip and Knee Reconstruction 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, pp 521-528.

The resultant spasticity and weakness (paresis) following a cerebrovascular accident leads to muscle imbalance that commonly results in contracture of the shoulder in adduction, internal rotation, and varying degrees of forward flexion. In addition, the elbow is usually flexed and the forearm pronated.
REFERENCES: Braun RM, Botte MJ: Treatment of shoulder deformity in acquired spasticity. Clin Orthop 1999;368:54-65.
McCollough NC III: Orthopaedic evaluation and treatment of the stroke patient. Instr Course Lect 1975;24:45-55.

A Charcot flare in adjacent joints is not uncommon in patients with neuropathy who undergo surgery or other trauma. Venous thrombosis would present with swelling of the entire leg, while infection would present earlier in the postoperative period. The radiographs are pathognomonic of Charcot arthropathy, not an unrecognized fracture or gout. A compartment syndrome this late after injury is extremely rare, and there would be no bony distraction associated with compartment syndrome.
REFERENCE: Connolly JF, Csencsitz TA: Limb threatening neuropathic complications from ankle fractures in patients with diabetes. Clin Orthop 1998;348:212-219.

This is an example of a closed sagittal band MP joint injury. The radial sagittal band ruptures , and the extensor tendon subluxes ulnarly . When the MP joint is flexed, it is difficult to fully extend it, but when the MP joint is held in full extension, active extension can maintain the position. In the setting of an extensor digitorum injury, extension cannot be maintained even if the MP joint is positioned in extension. The joint capsule is often injured when the sagittal band is injured, but repairing it will not restore extension. The radial collateral ligament of the MP joint is rarely injured with a sagittal band injury, and repairing it would not restore MP joint extension. When the MP joint is fully extended if the extensor tendon centralizes and full MP joint extension can be maintained, this injury usually is treated with a splint [yoke splint]) for 6 to 8 weeks. Surgery is recommended if the extensor tendon does not centralize with passive extension or if an injury is chronic. Surgery often is recommended for high-level athletes.
RECOMMENDED READINGS
16. Kleinhenz BP, Adams BD. Closed Sagittal Band Injury of the Metacarpophalangeal Joint. J Am Acad Orthop Surg. 2015 Jul;23(7):415-23. doi: 10.5435/JAAOS-D-13-00203. Review. PubMed PMID:
[26111875/. ](http://www.ncbi.nlm.nih.gov/pubmed/26111875)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/26111875)
17. [Catalano LW 3rd, Gupta S, Ragland R 3rd, Glickel SZ, Johnson C, Barron OA. Closed treatment of nonrheumatoid extensor tendon dislocations at the metacarpophalangeal joint. J Hand Surg Am. 2006 Feb;31(2):242-5. PubMed PMID: 16473685. ](http://www.ncbi.nlm.nih.gov/pubmed/16473685)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/16473685)
18. [Lin JD, Strauch RJ. Closed soft tissue extensor mechanism injuries (mallet, boutonniere, and sagittal band). J Hand Surg Am. 2014 May;39(5):1005-11. doi: 10.1016/j.jhsa.2013.11.018. Review. PubMed PMID: 24766832. ](http://www.ncbi.nlm.nih.gov/pubmed/24766832)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/24766832)

- Intraoperative neurological injury

There has been a recent increase in the use of outcome instruments to document and measure effects of treatment of medical conditions, including shoulder disorders. The most important feature of an instrument is whether it actually measures what it purports to measure; this is defined as its validity.
REFERENCES: Leggin BG, Iannotti JP: Shoulder outcome measurement, in Iannotti JP, Williams GR (eds): Disorders of the Shoulder: Diagnosis and Management. Philadelphia, PA, Lippincott Williams and Wilkins, 1999, p 1027.
Norris TR (ed): Orthopaedic Knowledge Update: Shoulder and Elbow. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, pp 47-55.

The radiographs show osteochondritis dissecans of the capitellum and a loose body in the anterior compartment. Arthroscopic removal is indicated because symptoms referable to the loose body are present.
REFERENCES: Baumgarten TE: Osteochondritis dissecans of the capitellum. Sports Med Arthroscopy Rev 1995;3:219-223.
Shaughnessy WJ, Bianco AJ: Osteochondritis dissecans, in Morrey BF (ed): The Elbow and Its Disorders, ed 2. Philadelphia, PA, WB Saunders, 1993, pp 282-287.

DISCUSSION: Closed chain kinetic exercises confer a margin of safety and are protective of healing or repaired tissues by the compressive nature of the applied forces. Closed chain kinetic exercise is associated with decreased shear, translation, and distraction of the joints within the chain. Because of patterns of motion with closed chain kinetic exercises, individual muscles may not be maximally strengthened or all joint motion returned to normal. Closed chain kinetic exercises may be used earlier in the rehabilitation process.
REFERENCES: Kibler WB, Livingston B: Closed-chain rehabilitation for upper and lower extremities. J Am Acad Orthop Surg 2001;9:412-421.
Garrick JG (ed): Orthopaedic Knowledge Update: Sports Medicine 3. Rosemont, IL, American Academy of
Orthopaedic Surgeons, 2004, pp 131-132.

This patient has ischiofemoral impingement, in which there is abnormal contact between the lesser trochanter and the lateral border of the ischium. Patients typically present with posteriorly based hip pain and do not respond to intra-articular diagnostic injections. Examination can demonstrate pain with long strides, pain with palpation over the area, as well as reproduction of symptoms with the patient in the contralateral decubitus position and taking the affected hip into passive extension (ischiofemoral impingement test). MRI demonstrates a narrowed ischiofemoral space, as well as increased signal within the quadratus femoris muscle. The diagnosis can be confirmed with a diagnostic injection into this area. Treatment is typically nonsurgical, with surgical intervention consisting of resection of the lesser _trochanter reserved for refractory cases._

---

Reduction, either open or closed, with internal fixation (pinning) is the recommended treatment for the majority of these injuries. Closed reduction with pinning is most often performed for acute injuries. Open reduction with pinning is performed for those injuries that cannot be reduced by closed means or those with a delayed presentation. Four cases of successful closed reduction and splinting, all performed upon presentation in the emergency department, have been described by Storken and associates, but the authors note that their review of three prior reports uncovered cases of secondary dislocation, which required surgical stabilization. One of the dislocations occurred 4 months after the reduction. They assert that an indication for primary ORIF is a CMC dislocation associated with major fractures. Primary arthrodesis can be considered in cases with severe intra-articular comminution, but this procedure substantially limits the ability of the hand to increase and decrease the transverse metacarpal arch, which is an important functional movement. It can also lead to osteoarthritis of the triquetrohamate joint. Suspension arthroplasty has been described for old fracture-dislocations of the fifth CMC joint, using a partial slip of the extensor carpi ulnaris.

---

---

---

■
The patient has a C1 burst fracture, as well as a grossly displaced C2 fracture. Surgical treatment should be considered for this patient who has good baseline function and wellcontrolled medical comorbidities. A cervical collar would not offer adequate stabilization for this fracture. Anterior reduction of this C2 fracture would be difficult, and screw fixation of C2 would not address the C1-C2 instability. A halo vest is considered a relative contraindication in the older patient population. Therefore, posterior C1-C2 fixation is the most appropriate choice.

DISCUSSION: Treatment of patellofemoral instability after total knee arthroplasty (TKA) is directed by its etiology. In instances of component malpositioning, revision of one or both components is indicated.
If the components are determined to be in satisfactory position, soft-tissue procedures can be pursued. Lateral retinacular release is usually the first soft-tissue procedure used to improve patellofemoral mechanics. In this patient, the patellar fracture fragment is so small that it can be excised. Distal realignment is not usually used as the first line of treatment for patellar maltracking following TKA.

REFERENCES: Fehring TK, Christie MJ, Lavemia C, et al: Revision total knee arthroplasty: Planning, management, and controversies. Instr Course Lect 2008;57:341-363.
Patel J, Ries MD, Bozic KJ: Extensor mechanism complications after total knee arthroplasty. Instr Course Lect 2008;57:283-294.

The contracture is too large for a Z-plasty, which allows a 75% increase in length. Excision of the scar with placement of a skin graft is prone to contracture. A posterior interosseous fasciocutaneous flap will provide enough well-vascularized tissue and is well suited to reach the first dorsal web space.
REFERENCES: Buchler U, Frey HP: Retrograde posterior interosseous flap. J Hand Surg Am 1991;16:283-292.
Brunelli F, Valenti P, Dumontier C, et al: The posterior interosseous reverse flap: Experience with 113 flaps. Ann Plast Surg 2001;47:25-30.

Rheumatoid arthritis is a chronic inflammatory synovitis. The neck is a common site of involvement, after hands and feet. Fortunately, radiographic evidence of instability does not equal neurological deficits. The 3 most common cervical presentations are atlantoaxial subluxation, basilar invagination, and subaxial subluxation. Atlantoaxial subluxation is attributable to an incompetent transverse ligament or erosion of the dens. It is demonstrated by a widened anterior atlantodental interval. Basilar invagination is attributable to cranial settling with the tip of the dens pressing on the spinal cord or midbrain. Subaxial subluxation is attributable to the destabilization of the facet joints.
Basilar invagination symptoms can include posterior headaches, cervical myelopathy, dizziness, and sudden death from compression of the medulla oblongata. In this scenario, there is no subaxial or atlantoaxial subluxation or rheumatoid plaque.
RECOMMENDED READINGS
17. [Fujiwara K, Owaki H, Fujimoto M, Yonenobu K, Ochi T. A long-term follow-up study of cervical lesions in rheumatoid arthritis. J Spinal Disord. 2000 Dec;13(6):519-26. PubMed PMID: 11132984. ](http://www.ncbi.nlm.nih.gov/pubmed/11132984)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/11132984)
18. Boden SD, Dodge LD, Bohlman HH, Rechtine GR. Rheumatoid arthritis of the cervical spine. A longterm analysis with predictors of paralysis and recovery. J Bone Joint Surg Am. 1993 Sep;75(9):1282-
[97/. PubMed PMID: 8408150. ](http://www.ncbi.nlm.nih.gov/pubmed/8408150)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/8408150)
19. [Riew KD, Hilibrand AS, Palumbo MA, Sethi N, Bohlman HH. Diagnosing basilar invagination in the rheumatoid patient. The reliability of radiographic criteria. J Bone Joint Surg Am. 2001 Feb;83-A(2):194-200. PubMed PMID: 11216680. ](http://www.ncbi.nlm.nih.gov/pubmed/11216680)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/11216680)

Tissues that are principally composed of collagen and fibroblasts are low signal on both T1 and T2 weighted sequences include tendons, ligaments, and fascial layers.
It is important to remember the appearances of common tissues on both T1 and T2 weighted images:
 T1 weighted T2 weighted
Fat High Moderate Tendons Low Low Ligaments Low Low Fascial layers Low Low Cortical bone Low Low Muscle Moderate Moderate Normal marrow High Moderate Soft tissue sarcomas Low High
Fluid (ganglions, effusions) Low High
Pigmented villonodular synovitis* Very low Very low
Signal drop out (very low signal on gradient echo sequences) Correct Answer: Tendons

Little League shoulder is a physeal injury increasingly seen in young throwers. The primary treatment is refraining from throwing with rehabilitation, followed by a throwing program. The risk of recurrence is approximately 7%. The risk of recurrence is three times higher in athletes with glenohumeral internal rotation deficit. Hyperlaxity,
rotator cuff weakness, and increased height have not been shown to correlate with recurrent symptoms.

Treatment of a comminuted bicondylar tibial plateau fracture such as the one shown in Figures A and B is best treated with dual plates (or more), as the posteromedial fragment(s) is usually a large section of the medial plateau and is poorly stabilized from a single lateral plate.
Barei et al (2008) retrospectively reviewed 57 patients with bicondylar tibial plateau fractures, evaluating the frequency and morphologic characteristics of the posteromedial fragment in this injury pattern. They found that 74% of these injuries had a posteromedial fragment that may require alternate or supplementary fixation methods when managing this injury pattern.
Barei et al (2006) reviewed 83 bicondylar tibial plateau fractures that were treated with medial and lateral plate fixation through two exposures. They noted that residual dysfunction is common. Accurate articular reduction was possible in about 55% of the patients and the reduction was associated with better outcomes within the confines of the injury severity.
Figure A and B show a comminuted bicondylar tibial plateau fracture. Figure C
is an axial CT cut showing the medial fragments (anterior and posterior).
Incorrect Answers:
Answer 1: Definitive use of the spanning external fixator would lead to significant knee stiffness.
Answer 2: Conversion to a hinged knee fixator is not commonly recommended for this injury pattern.
Answer 3: This comminuted tibial plateau fracture is not amenable to treatment with an intramedullary nail.
Answer 4: Use of more than one plate to instrument this fracture is necessary.

- reverse total shoulder arthroplasty (rTSA)._

- Plantar plate

Each of the alternatives presented is reasonable except for ankle arthroscopy because it has a limited role in the management of posttraumatic arthritis of the ankle. In this patient, there is a possibility to salvage the ankle before arthrodesis or joint replacement with an osteotomy of the tibia and or the fibula. Both have a definite role in management of ankle deformity and arthritis. A closing wedge osteotomy of the tibia was performed in this patient, and she remains asymptomatic 4 years later (Slide
3 and Slide 4).

Two copies of a mutant allele are required to reduce enzyme function to levels that cause clinical impairment.
Enzyme defects are rarely inherited by an autosomal dominant pattern because even half of the normal activity of most enzymes is adequate to maintain normal function.
Enzyme defects are rarely inherited in an X-linked dominant pattern because one copy of a mutant allele is usually sufficient.
Multifactorial inheritance refers to the interaction of multiple, or different genes, to produce a disorder. Enzyme deficiencies are typically the result of a defect in a single gene.
Because enzymes are typically coded by a single gene, they follow mendelian patterns.

■
The patient has a low-grade but high-dysplastic spondylolisthesis (vertical and domed sacrum) with severe spinal canal stenosis. The MRI scan shows the dysplastic sacrum and severe central stenosis associated with an intact pars interarticularis, bulging L5-S1 disk, and domed posterior sacrum. Although many treatments are available for low-grade isthmic spondylolisthesis, this spondylolisthesis condition requires a complete laminectomy and possible sacral dome resection because of the severe central stenosis with an intact pars interarticularis (no lysis) in a patient with early neurological signs (Figures 6 and 7 are CT scans of the L5 pars without evidence of a lysis). Patients with dysplastic spondylolisthesis without a lysis can develop cauda equina syndrome with loss of bowel/ bladder function and weakness of the gastrocsoleus muscles (sacral nerve roots) and should be recognized and treated with appropriate laminectomy decompression followed by spinal fusion, typically with posterior instrumentation and interbody fusion. A “Gill” laminectomy is described as removal of the lamina from pars interarticularis lysis and including the abnormal inferior facets. There is no lysis in this patient, and while laminectomy is needed, a Gill laminectomy is not possible. Transforaminal interbody fusion and percutaneous instrumentation does not address the central spinal stenosis.

The most common specific site of involvement is the origin of the extensor carpi radialis brevis. It is usually caused by overuse activities, such as the eccentric overload exhibited during a backhand in tennis. In most patients, the characteristic friable, grayish tissue described as angiofibroblastic hyperplasia or hyaline degeneration is seen at the extensor carpi radialis brevis origin.
REFERENCES: Nirschl RP: Elbow tendinosis/tennis elbow. Clin Sports Med 1992;11:851-870.
Regan W, Wold LE, Coonrad R, Morrey BF: Microscopic histopathology of chronic refractory lateral epicondylitis. Am J Sports Med 1992;20:746-749.

--The patient is provided with a medial unloader brace that provides substantial pain relief and he is able to work while wearing the brace. After 4 months he returns to work and says that while the brace enable him to work, it is uncomfortable. Consequently, his symptoms return when he is not wearing the brace and he is requesting a surgical intervention for his problem. What is the most appropriate surgical treatment?

1) Valgus-producing high tibial osteotomy (VPHTO)

2) Repeat knee arthroscopy

3) Total knee arthroplasty (TKA)

4) Medial meniscus transplant

--The patient is offered a VPHTO. What aspect of his history will determine the most appropriate VPHTO technique?

1) Prior arthroscopy

2) Current smoking history

3) BMI of 22

4) Age of 40

FOR QUESTIONS 13 THROUGH 16_
This patient has a classic presentation of postmeniscectomy medial compartment arthritis. The appropriate diagnostic study is weight-bearing radiographs to confirm the diagnosis. An MRI scan will reveal medial compartment arthritis but will not provide information about alignment. A CT scan would be appropriate to detect an occult fracture; however, this condition is not suspected in this clinical scenario. An ultrasound can provide information about fluid collection around the knee or a deep vein thrombosis; however, these conditions also are not suspected in this clinical scenario.
Because the patient has a correctable deformity (gaps 3 mm with valgus stress) and his symptoms are localized to the involved compartment, a trial of a medial unloader brace is appropriate both diagnostically and therapeutically. If unloading the medial compartment resolves the patient’s symptoms, he would be an excellent candidate for an osteotomy. An MRI scan may be obtained to evaluate ligamentous integrity or to evaluate degenerative involvement of the lateral and patellofemoral compartment for presurgicalplanning of an osteotomy; however, the integrity of the medial meniscus has no clinical importance in a patient with severe medial compartment arthritis. A repeat corticosteroid injection is not indicated within 1 month of his last injection, and referral to pain management is not appropriate with other options available to help this patient.A VPHTO is the appropriate intervention considering the patient’s young age, high-functional occupation,examination, radiographic findings, and response to medial unloader bracing. A revision knee arthroscopy would be appropriate for a recurrent medial meniscus tear, but not in a patient with severe medial compartment arthritis. The patient’s young age and high functional requirements are contraindications to TKA. The presence of severe arthritis is a contraindication to medial meniscus transplant. The patient is a candidate for a VPHTO. The technical options include a medial opening-wedge or a lateral closing-wedge osteotomy. Both techniques have advantages and disadvantages; however, a medial opening-wedge osteotomy is contraindicated in a smoker because of concern for nonunion. As a result,current smoking history is the only factor listed that would influence the technique used. The history of prior arthroscopy has no relevance in the decision about which type of osteotomy is appropriate. Normal BMI is between 18.5 and 24.9, so this patient’s BMI is considered normal and would not affect the surgical technique (if this patient were obese, a lateral closing-wedge osteotomy would be considered, but this is controversial). His age of 40 is an indication for HTO but does not influence technique.

-When reconstructing the anterior cruciate ligament (ACL), what is the most common source of potential autograft failure?

1) Graft choice

2) Tunnel position

3) Tibial fixation

4) Femoral fixation

_CLINICAL SITUATION FOR QUESTIONS 18 THROUGH 20_
A 25-year-old healthy woman injured her left knee while playing professional soccer. She has never injured this knee before. Examination 2 days after the injury occurred reveals the following: a moderate effusion, a positive Lachman test result, and mild lateral tenderness. Range of motion is between 20 degrees and 70 degrees. Radiographs reveal no fracture. An MRI scan reveals a complete rupture of the anterior cruciate ligament (ACL), an effusion, and bone bruises of the lateral femoral condyle and lateral tibial plateau. No meniscal tear is seen. The patient would like to continue playing at the professional level.

--What is the next treatment step?

1) Immobilization of the knee for 6 weeks, followed by rehabilitation and delayed ACL reconstruction

2) Immediate ACL reconstruction

3) Immediate rehabilitation for 6 months followed by ACL reconstruction if the patient is unstable in a brace

4) Immediate rehabilitation with delayed ACL reconstruction (when the athlete obtains full knee range of motion)

-What is this patient’s risk for developing osteoarthritis (OA) of the knee?

1) There is no risk for development of knee OA after reconstruction of the ligament.

2) There is no risk for development of knee OA after a double-bundle ACL reconstruction.

3) There is no evidence that ACL reconstruction reduces the incidence of knee OA.

4) There is 100% likelihood that she will develop knee OA after single-bundle ACL reconstruction.

-The patient asks if something about her anatomy has resulted in this injury. ACL anatomy differs between men and women in what manner?

1) There is no significant difference in ACL anatomy between men and women.

2) A woman’s ACL has a smaller cross-sectional area.

3) The cross-sectional area of a woman’s ACL is larger.

4) The intercondylar notch is wider in women than in men.

FOR QUESTIONS 18 THROUGH 20_
This patient has the clinical findings of an ACL rupture that is confirmed on MRI scan. She is a professional athlete and would like to return to her sport. Immediate ACL reconstruction in the setting of a knee with limited motion carries an increased risk for postsurgical stiffness. Delayed surgery after the patient regains range of motion is the preferred response. It has been shown that a woman’s ACL is smaller in the cross-sectional area.

-Figure 21 is the radiograph of a 31-year-old man who had left shoulder pain after a fall during a snow boarding jump. Residual displacement of 5 mm after closed reduction is most likely to result in which of the following?

1) Nonunion

2) Osteonecrosis

3) Altered rotator cuff mechanics

4) Normal shoulder function

-What strategy has proven most effective in preventing transmission of methicillin-resistant Staphylococcus aureus among teammates?

1) Separate players with infections in a separate locker room or changing area.

2) Treat teammates of the infected player with prophylactic antibiotics.

3) Cover any skin lesions with occlusive dressing during sporting activity.

4) Ban players with infections from any team event.

-Figure 23 is the T2 axial MRI scan of a 21-year-old man who was injured while playing for his college football team. His pain was aggravated with blocking maneuvers and alleviated with rest, and he had to stop playing because of the pain. What examination maneuver most likely will reproduce his pain?

1) Forward elevation in the scapular plane

2) External rotation and abduction

3) Flexion, adduction, and internal rotation

4) Flexion and abduction

_**CLINICAL SITUATION FOR QUESTIONS 24 AND 25**_
During the third quarter of a high school football game, a 16-year-old running back gets tackled and limps off the field. During the initial sideline evaluation, he has tenderness on the right iliac crest. He is a little dizzy, has a headache, and tells you, “I need to get back in the game to help the team score before halftime.”

-How can this scenario be managed most effectively?

1) Initiate rest, ice the iliac crest, and return to play when he is not limping.

2) Initiate rest, ice the iliac crest, and return to play after 20 minutes.

3) Keep the player on the sideline, perform a cognitive evaluation, and repeat the physical assessment.

4) Keep the player out of the game and send him emergently to the hospital for imaging.

-Sideline examination of this patient showed no cervical pain or tenderness; motor and sensory function were normal; and his pupils were equal, round, and reactive. He was alert and oriented to the score of game, time on the clock, and current quarter of play. His iliac crest had mild tenderness but no swelling or crepitus. The player states that he has a slight headache and is no longer dizzy. What is the most appropriate treatment?

1) Return him to the game and observe his play closely.

2) Do not return to the game and do not allow play for the remainder of the season.

3) Do not return to the game and begin a graduated return-to-play protocol for future games.

4) Perform a sideline noncontact exercise testing examination and return him to the game if he is asymptomatic.

FOR QUESTIONS 24 AND 25_
Although this player limps off the field, the fact that he felt dizzy, had a headache, and did not initially recognize that he was playing in the third quarter indicates that he sustained a concussion. The player should be kept out of the game until a cognitive examination and repeat physical assessment is completed.Even if his physical symptoms have resolved, a certain period of time has expired, or he states that he is“ready,” he should not be returned to play prior to this assessment. Sending the patient to an emergency department should be considered only after this assessment and appropriate initial sideline treatment is initiated. The Consensus Statement on Concussion in Sport recommends that no athlete with concussion symptoms be returned to same-day play. This patient still has a slight headache, but even if this resolved he should not return to the game. Adolescents and high school athletes may have neurophysiological deficits that may not be evident on the sideline, or they may have a delayed onset of symptoms. A graduated return to play for future games is recommended.
_CLINICAL SITUATION FOR QUESTIONS 26 THROUGH 29_
A 32-year-old woman has a 2-year history of progressively worsening right groin pain that is exacerbated by activity. She reports no traumatic injury and an extensive work-up by her gynecologist has ruled out an intrapelvic source of her pain. The patient is a recreational athlete and exercises regularly in the gym.The pain is preventing her from performing these activities. She reports no catching or locking symptoms.Her examination reveals a physically fit female (BMI of 20) with limited right hip range of motion. She has no tenderness to palpation around the hip. While lying supine and bringing her hip into progressive flexion with internal rotation and adduction, her groin pain is reproduced. She has normal limb lengths and demonstrates weakness secondary to pain with hip flexion on the affected side.

-What is the most likely cause of this patient’s groin pain?

1) Femoroacetabular impingement (FAI)

2) Osteoarthritis of the sacroiliac joint

3) Intra-articular loose body

4) Trochanteric bursitis

-The patient is enrolled in physical therapy for 6 weeks with little improvement of her hip symptoms.What is the next most appropriate diagnostic test to determine the presence of an associated acetabular labral tear in this patient?

1) Diagnostic arthroscopy of the hip

2) MRI scan of the hip

3) MRI arthrogram of the hip

4) Ultrasound of the hip

-The study obtained in confirms the presence of an anterosuperior acetabular labral tear and pincer morphology of the acetabulum. What is the most likely location of a chondral injury associated with these findings?

1) Posteroinferior acetabulum

2) Posterosuperior acetabulum

3) Femoral head above the fovea

4) Femoral head below the fovea

-The patient experienced little improvement with activity modification and physical therapy. An intraarticular corticosteroid injection provides excellent but short-lived pain control. She requests surgical treatment for her hip and she is counseled regarding arthroscopy and consent is obtained. Intraoperatively,a capsulolabral separation is observed with an underlying pincer lesion. No articular cartilage injury is seen. What treatment is most appropriate considering these findings?

1) Suture anchor repair of the labral tear and no bony resection

2) Suture anchor repair of the labral tear and bony resection of the pincer lesion

3) Debridement of the labral tear and bony resection of the pincer lesion

4) Debridement of the labral tear with no bony resection of the pincer lesion

FOR QUESTIONS 26 THROUGH 29_
The clinical scenario, examination, and MRI scans are consistent with a pincer-type FAI. The decreased range of motion is secondary to the pain produced by the continued abutment of the femoral head against the anterosuperior acetabulum. Flexing the hip while internally rotating and adducting the leg recreates this contact and is typically painful. No clinical signs suggest sacroiliac joint arthritis, an intra-articular loose body, or trochanteric bursitis, although these are all diagnoses that should be considered in a patient with a painful hip. The most sensitive and specific study to detect an acetabular labral tear is an MRI arthrogram of the hip. This study should be obtained in this patient to evaluate the labrum as well as the status of the articular cartilage. An MRI scan without intra-articular contrast is not as sensitive as an arthrogram. An ultrasound can provide a dynamic assessment of the hip and help in the setting of a snapping hip; however, this study is not reliable to determine the presence of a labral tear. In the setting of pincer FAI, the forced leverage of the anterosuperior femoral head upon the anterior acetabulum results in abnormal forces against the posteroinferior acetabulum. This continued force can lead to a chondral lesion in this location know as a “counter-coup” injury. Chondral lesions of the femoral head are rare in the setting of pincer FAI. The posterosuperior quadrant does not experience increased force and rarely sustains chondral injuries. The patient is a young, active individual with no pre-existing degenerative changes, so repair of the tear with bony resection of the pincer lesion is the most appropriate treatment.A capsulolabral detachment should be repaired because these tears can heal and the labrum functions as a seal, preventing egress of synovial fluid from the joint space. If the pincer lesion is not resected, the patient will continue to experience abnormal contact and the repair will likely fail. There is no evidence that the patient has a cam impingement, and recontouring of the femoral head/neck junction is not appropriate. Simple debridement should be reserved for intrasubstance tears of the labrum, which would not be expected to heal with repair.
_**CLINICAL SITUATION FOR QUESTIONS 30 THROUGH 32**_
Figures 30a and 30b are the radiographs of a 20-year-old college multisport athlete who has had longstanding pain in his left hip. He denies any specific event that initiated his pain, but he notes that he had hip problems when he was an infant. He denies pain with activities of daily living, but he
believes his pain is increasingly limiting his ability to exercise. He localizes the pain to his groin. He denies low-back or buttock pain or pain that radiates down his leg.

-What examination findings are most consistent with the pathology seen in the radiographs?

1) Pain with resisted hip flexion

2) Pain with a half sit-up, plus tenderness at the pubic ramus

3) Pain with a combination of hip flexion, adduction, and internal rotation

4) Tenderness to palpation at the greater trochanter

-What is the most likely diagnosis for the source of this patient’s pain?

1) Cam-type femoroacetabular impingement

2) Pincer-type femoroacetabular impingement

3) Hip flexor strain

4) Athletic pubalgia

-Images from an MRI scan of this patient’s left hip are shown in Figure 30c through 30e. What is the most likely cause of his acute pain?
1) Significant cartilage loss on the acetabulum

2) Labral tear

3) Femoral neck stress fracture

4) Tendonopathy of the rectus femoris

FOR QUESTIONS 30 THROUGH 32_
This patient has cam-type femoroacetabular impingement. Decreased internal rotation and a positive impingement test (forced flexion, adduction, and internal rotation) are classic findings. The lack of pain with resisted hip flexion makes hip flexor strain unlikely, and the lack of tenderness at the greater trochanter renders trochanteric bursitis unlikely. Although athletic pubalgia can be a source of longstanding groin pain, he lacks the pain with a resisted sit-up and tenderness along the pubic ramus that is frequently noted in patients with pubalgia. His radiographs reveal a focal femoral neck prominence consistent with cam impingement, although pistol grip deformities and flattening of the lateral femoral head are often present as well. His MRI scan shows a labral tear, which is common in cam impingement.Surgical treatment for cam impingement can be effective for symptomatic patients. Even among highlevel athletes, open surgical dislocation of the hip has been shown to have good results. Most patients with cam impingement can be treated with arthroscopic osteoplasty and achieve results comparable to those realized with open surgical dislocation. The literature describes success in terms of athletes returning to sports (even professional athletes) to be approximately 90% after arthroscopic treatment.Byrd and Jones described 5 patients who developed transient neurapraxias that resolved uneventfully.The patients in his series who had concomitant microfracture had a 92% return to sports within the follow-up period. Cam impingement has long been thought to be associated with a history of a slipped capital femoral epiphysis. The capitis in these patients is displaced posteriorly, resulting in a prominent anterior femoral neck and decreased hip internal rotation. Pincer impingement is associated with a deep acetabulum, such as protrusion acetabula and acetabular retroversion. A patient who underwent a periacetabular osteotomy can develop a more retroverted acetabulum as well.

-A 25-year-old recreational soccer player has recurrent shoulder dislocations. He first dislocated his shoulder playing football in high school, was treated in a sling for 6 weeks, and returned to play for the remainder of the season. He did well until 2 years later when he reinjured the shoulder. He says that his shoulder dislocates with little injury and always “feels loose.” Examination reveals anterior instability and an MR arthrogram reveals an anterior-inferior labral tear and surgical treatment is recommended. He inquires about the benefits of arthroscopic vs open procedure. Which of the following statements reflects an advantage associated with arthroscopic procedures compared to open stabilization?

1) Range of motion might be slightly better after an arthroscopic procedure.

2) Rate of recurrent instability is lower after an arthroscopic procedure.

3) Rates of return to work are higher after an arthroscopic procedure.

4) Rates of return to sports are higher after an arthroscopic procedure.

-Figures 34a and 34b are the radiographs of a 38-year-old woman who had increasing left hip pain with activity. She noted no lower back or buttock pain and no pain along her lateral thigh. The pain usually only bothers her with running and cycling.
Nonsteroidal anti-inflammatory drugs helped initially but are not relieving her pain now. Examination with the patient supine reveals pain with internal and external rotation of her hip
with her hip and knee in an extended position. With her hip flexed to 90 degrees, she has internal rotation only to neutral, but full external rotation. What is the most likely diagnosis?
1) Cam-type femoroacetabular impingement

2) Pincer-type femoroacetabular impingement

3) Intra-articular loose body

4) Snapping psoas tendon

-A 24-year-old former high school wrestler had anterior cruciate ligament (ACL) reconstruction with hamstring autograft 6 years ago. He now experiences daily instability of his knee with routine activities including walking. Examination reveals a grade 3+ Lachman with a soft endpoint, varus laxity at 30 degrees, and a positive dial test at 30 degrees that dissipates at 90 degrees of knee flexion. He has mild medial joint line tenderness. When walking, there is a slight varus thrust. What treatment is most likely to lead to a successful outcome?

1) Hamstring autograft

2) Revision ACL reconstruction and posterior cruciate ligament (PCL) reconstruction

3) Revision ACL reconstruction and posteromedial corner reconstruction

4) Revision ACL reconstruction and posterolateral corner reconstruction

-A 49-year-old man is seeking a second opinion for continued knee pain and swelling. He went to his primary doctor for swelling “on top of his knee,” and he says his doctor drained some clear fluid. He noted that his condition improved for about 1 week before the swelling returned. He now has increasing pain and redness around his kneecap.
Examination reveals significant swelling of his prepatellar bursa,with erythema over the bursa that extends to the surrounding skin. His temperature in the office is 101.7°F. What is the next step in treatment for this patient?

1) Initiate oral antibiotics for 7 days.

2) Reaspirate the bursa and inject a corticosteroid.

3) Recommend padding the patella for kneeling and ice.

4) Perform an open bursectomy and start intravenous antibiotics.

_CLINICAL SITUATION FOR QUESTIONS 37 AND 38_
An 18-year-old right-hand-dominant college freshman who is a third baseman has pain in his right shoulder after using his outstretched right arm for support while diving to catch a low line drive. He describes pivoting on his right hand and arm while reaching out to make the catch with his left-hand glove. He had pain in his shoulder but was able to finish the game with some pain while throwing. Five days later, he experiences popping pain deep in his shoulder that has improved since the injury but continued to be bothersome deep in the shoulder with higher-velocity throwing. Examination demonstrated decreased internal rotation, posterior pain with cross-body adduction and posteriorly directed force, and full rotator cuff strength. Radiograph findings were normal. After 6 weeks of physical therapy (PT), his range of motion has improved but he continues to experience deep pain with therapy. Examination shows symmetric range of motion and posterior pain with the jerk test and Kim test. His rotator cuff is strong.Figure 37a Figure 37b

-What is the next step in treatment?

1) Continued PT

2) Subacromial injection

3) CT scan

4) MRI arthrogram

-T1-weighted, fat-saturated MRI scans are shown in Figures 37a and 37b. What is the next step intreatment?

1) Open reduction internal fixation (ORIF)

2) Rotator cuff repair

3) Labrum repair

4) Chondroplasty

FOR QUESTIONS 37 AND 38_
Examination findings of posterior glenohumeral tenderness, decreased internal rotation, and reproduction of symptoms with a posterior stress test indicate a posterior shoulder injury or instability. The jerk test,with the patient seated, positions the arm in forward flexion and internal rotation with elbow flexion. One hand of the examiner is placed on the patient’s distal clavicle and scapular spine and the other hand grasps the elbow. The arm is jerked posteriorly while the shoulder girdle is jerked anteriorly, which creates pain as the posteriorly subluxated humeral head relocates into the glenoid fossa. During the Kim test, the patient is seated with the arm in 90 degrees of abduction. While the arm is elevated 45 degrees diagonally (forward flexion and adduction), the examiner applies an axial load to the elbow and a downward and posterior force to the upper arm. A positive result causes a sudden onset of posterior shoulder pain. A positive jerk test combined with a positive Kim test has a 97% sensitivity for posterior instability. After extensive PT, the patient continues to have examination findings consistent with posterior shoulder injury or instability, so an MRI scan or MRI arthrography would be helpful to assess for any pathology.A subacromial injection is not indicated by this examination, which shows a strong rotator cuff and no demonstrated bursal-sided symptoms. A CT scan can be helpful in scenarios involving bony pathology,but an MRI is indicated at this stage in the evaluation of soft tissue. Although continuing PT may help to abate symptoms, the patient was continuing to have symptoms with PT. The MRI arthrogram shows a complex posterior labrum tear at the inferior to mid glenoid with separation of labrum from the glenoid. Because the examination findings are consistent with the MRI findings and nonsurgical treatment has failed to resolve symptoms, the next step is to recommend surgical treatment with labrum debridement and/or repair. No examination or MRI findings indicate a need for injection, rotator cuff repair, ORIF, or chondroplasty unless incidental intrasurgical findings are found.

A high school athlete sustained a noncontact injury to his right knee. He says that during a football game he felt a pop and his leg gave way. He attempted to continue to play but was unable secondary to pain.Five days after the injury, radiographs of his right knee do not reveal any abnormalities. On examination,he has an effusion on the injured side and no joint line tenderness. His range of motion is full extension to 110 degrees of flexion. At 20 degrees of flexion, he has increased anterior translation compared to the contralateral, uninjured left side. At 90 degrees of flexion, the tibia does not translate posteriorly. As his knee is moved from full extension into flexion with an internal rotation and valgus force, you notice a“clunk” within the knee. What is the most likely biomechanical basis for the “clunk”?

1) In extension, the medial tibial plateau is subluxated; as an internal rotation/valgus force is applied in conjunction with flexion, the medial tibial plateau reduces.

2) In extension, the medial tibial plateau is reduced; as an internal rotation/valgus force is applied in conjunction with flexion, the medial tibial plateau subluxates.

3) In extension, the lateral tibial plateau is reduced; as an internal rotation/valgus force is applied in conjunction with flexion, the lateral plateau subluxates.

4) In extension, the lateral tibial plateau is subluxated; as an internal rotation/valgus force is applied in conjunction with flexion, the lateral plateau reduces.

_**CLINICAL SITUATION FOR QUESTIONS 40 THROUGH 42**_
A 9-year-old boy was injured while playing soccer. His examination revealed painful range of motion between 5 degrees and 75 degrees. There is tenderness on the medial side of his knee. There is no effusion, a grade 1A Lachman, and severe pain over the medial epicondyle of the knee. Varus stress is negative and pain is elicited with valgus stress. Initial radiographs were negative for abnormality.

-What is the next diagnostic step?

1) Repeat radiographs while the patient is weight bearing

2) Ultrasound of the lower extremity and calf

3) Stress radiographs

4) CT scan

-What is the most likely area of injury?

1) Femoral attachment of the medial collateral ligament

2) Tibial attachment of the medial collateral ligament

3) Hypertrophic zone of the growth plate

4) Proliferative zone of the growth plate

FOR QUESTIONS 40 THROUGH 42_
This patient likely has a physeal injury to the distal femoral physis. Stress radiographs or an MRI scan will most reliably reveal this diagnosis. The growth plate, when injured, is most commonly fractured through the hypertrophic zone of cartilage, its weakest point. This patient is optimally treated in a cylindrical or long-leg cast. Younger patients can be treated with a hip spica with a leg extension.

-An otherwise healthy 15-year-old wrestler has a 6-cm cutaneous lesion on the posterior aspect of his right elbow that he reports as a spider bite. What is the most likely diagnosis?

1) Psoriasis

2) Tinea corporis

3) Herpes simplex virus

4) Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA)

_CLINICAL SITUATION FOR QUESTIONS 44 AND 45_
Figure 44 is the MRI scan of a 14-year-old soccer player who injured his right knee during a game.He describes feeling a “pop” and he needed help walking off the field. His knee is visibly swollen. A Lachman test demonstrates asymmetry with no endpoint.

-Range of motion of the knee is between 0 degrees and 70 degrees. What is the most appropriate treatment option?

1) Nonweight-bearing activity with crutches

2) Microfracture of the chondral defect

3) Immediate anterior cruciate ligament (ACL) reconstruction

4) Delayed ACL reconstruction

-The patient has no postsurgical complications and begins physical therapy rehabilitation. The boy and his parents stress they “want to get the therapy over with as fast as possible” to expedite his return to sports,and the surgeon and rehabilitation team consider their request. Compared to nonaccelerated rehabilitation,patients who follow an early accelerated rehabilitation protocol experience

1) increased laxity.

2) no differences in long-term results.

3) increased risk for graft failure.

4) lower Knee Injury and Osteoarthritis Outcome Scores (KOOS).

FOR QUESTIONS 44 AND 45_
The Lachman test is the most sensitive examination for acute ACL injuries. ACL injury rates are higher in women than in men. This likely is attributable to anatomic differences (smaller notches, smaller ligaments, and different landing biomechanics). Lateral meniscal tears are more common than medial tears. The anterior drawer test is accentuated with 30 degrees of external rotation of the tibia. The MRI scan shows bone bruises consistent with an ACL tear. It is also always necessary to examine other structures of the knee in patients with ACL tears. All ligaments of the affected knee should be assessed.Lateral meniscal tears are frequently associated with ACL tears. Medial meniscal tears and posterolateral corner deficiency are also possible. Randomized clinical trials comparing an early accelerated vs nonaccelerated rehabilitation have demonstrated no significant differences in long-term results. These studies did not address timing of return to play with an early accelerated rehabilitation program. At 2 and 3 years postsurgically, there are no differences in laxity, number of graft failures, or KOOS scores.

-Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease that is characterized by

1) onset most often by age 30.

2) a temporary state of neuronal and axonal derangement.

3) manifestations of affect such as apathy, irritability, and suicidal ideation.

4) absence of gross pathological brain changes upon autopsy.

-In the shoulder position of 90-degree forward flexion and internal rotation, what is the most important static stabilizer of the glenohumeral joint?

1) Rotator interval

2) Infraspinatus

3) Anterior band of the inferior glenohumeral ligament

4) Posterior band of the inferior glenohumeral ligament

_**CLINICAL SITUATION FOR QUESTIONS 48 AND 49**_
A 17-year-old high school wrestler sustains an abrasion over the posterior aspect of his right elbow during a match. During the next few days the abrasion becomes erythematous and he is placed on oral cephalexin 500 mg four times per day. The erythema extends proximally despite the antibiotic regimen. The patient is afebrile, there is no fluid collection associated with the lesion, and his elbow joint is not involved.

-What is the most appropriate treatment?

1) Switch to oral trimethoprim-sulfamethoxazole double-strength twice per day for 10 to 14 days

2) Switch to oral ciprofloxacin 500 mg twice per day for 10 to 14 days

3) Begin cefazolin 1 gram intravenously (IV) every 8 hours for 7 to 10 days

4) Irrigation and debridement with empiric IV antibiotic coverage

-Assuming that the lesion can be covered appropriately and there is no drainage from the lesion, when should the patient be allowed to safely return to wrestling?

1) When the absence of pain is reported by the wrestler for 3 consecutive days

2) When 72 hours of antibiotics have been administered and there is no extension of the lesion for 48 hours

3) When laboratory values are within defined limits and the patient remains afebrile for 3 days

4) When the lesion has decreased in size by 50%

FOR QUESTIONS 48 AND 49_
This patient has cellulitis, which is typically caused by group A Streptococcus or Staphylococcus. The patient’s lack of improvement with first-line antibiotics is concerning for methicillin-resistant Staphylococcus aureus (MRSA) infection. MRSA cellulitis is becoming more prevalent in young athletes,and a high index of suspicion is required to provide appropriate intervention during this
aggressive disease process. The diagnosis is typically made clinically without the use of cultures. Oral trimethoprimsulfamethoxazole (a sulfonamide-class drug) double strength twice daily for 10 to 14 days or doxycycline (a tetracycline-class drug) 100 mg twice daily for 10 to 14 days are recommended for first-line treatment of suspected MRSA cellulitis. There is no indication to proceed with irrigation and debridement; however, if the patient develops a soft-tissue abscess or the underlying joint becomes involved, this would be an appropriate intervention. Switching the athlete to an IV cephalosporin (cefazolin) is not likely to be effective against the presumed resistant bacteria.
Ciprofloxacin (a fluoroquinolone-class drug) is effective against many bacteria, but not MRSA. The current recommendation for wrestlers with cellulitis is that return to competition be allowed after 72 hours of antibiotic treatment if there has been no extension of the cellulitis for 48 hours, the lesion can be covered, and there is no drainage from the lesion. The other responses are not current recommendations for return to competition.

-A 19-year-old linebacker underwent a coracoid transfer procedure for recurrent anterior glenohumeral instability. At his 1-week postsurgical check-up, his incision is doing well; however, he reports numbness over the lateral aspect of his forearm. What nerve may have been injured during his surgery?

1) Axillary

2) Median

3) Musculocutaneous

4) Radial

-What is the most important genetic element that distinguishes community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) from hospital-acquired MRSA?

1) Beta-lactamase

2) Penicillin-binding protein 2a

3) Panton-Valentine leukocidin (PVL)

4) Staphylococcus cassette chromosome (SCCmec) type I

_CLINICAL SITUATION FOR QUESTIONS 52 THROUGH 54_
A 13-year-old baseball player fell while rounding second base 2 days ago. He said it felt like his knee buckled when he turned toward third base. He could not finish the game, but was able to bear weight with a limp. He has had no previous knee injuries, but now complains of pain in his right knee. Initial examination demonstrated an effusion, tenderness at the proximal medial collateral region and medial patellofemoral retinaculum, decreased range of motion, and patella apprehension. He was otherwise ligamentously stable. No other noteworthy physical findings were found.

-What is the next treatment step?

1) Radiographs

2) Arthroscopy

3) MRI scan

4) Duplex ultrasound

-What do the radiographs shown in Figures 52a and 52b reveal?

1) Medial femoral chondyle physeal widening

2) Osseous or osteochondral loose fragment

3) Osgood-Schlatter disease

4) Patella nondisplaced fracture

-Figures 52c and 52d show the proton density fat-saturated MRI scans. Treatment at this stage includes arthroscopy and

1) early functional rehabilitation.

2) proximal realignment alone.

3) attempted internal fixation.

4) medial collateral ligament (MCL) repair.

FOR QUESTIONS 52 THROUGH 54_
This patient’s examination indicates a patellar or peripatellar knee injury. Initial evaluation with radiographs will assess for fracture, subluxation, or osteochondral injury. Examination findings did not demonstrate a need for emergent surgery, an MRI scan, or an ultrasound, so radiographs are the initial diagnostic imaging choice. Radiographs show an osseous or osteochondral loose fragment.
There is no evidence of obvious nondisplaced fracture or physeal changes. In suspected patella dislocation or subluxation with loose fragment seen on radiographs, an MRI scan is indicated. Lateral release alone is seldom indicated in a knee that was normal before injury. Acute proximal realignment has not been shown to alter long-term outcomes for first-time dislocators. The examination and MRI scan did not indicate a need for MCL repair. Closed reduction of the osteochondral fragment would not be indicated or appropriate for this injury. Treatment should consist of arthroscopy or arthrotomy and attempted internal fixation of this fragment. If fixation is not possible, the loose body can be removed.

-While obtaining informed consent for a lateral closing-wedge osteotomy, what complication should be discussed with the patient as exclusive to this procedure and not encountered in medial opening-wedge osteotomy?

1) Compartment syndrome

2) Plate breakage

3) Neurologic injury

4) Proximal tibiofibular joint disruption

_**CLINICAL SITUATION FOR QUESTIONS 56 THROUGH 58**_

Figure 56 is the MRI scan of a 15-year-old girl who had left knee pain after sustaining a noncontact twisting injury while playing soccer. She reported severe pain initially that has since improved. On examination, she had a large knee effusion with lateral joint line tenderness. Range of motion is from 5 degrees of extension to 70 degrees of flexion. She wishes to return to sports at her preinjury level of activity.

-What examination test is most likely to reveal abnormal findings?

1) Pivot shift test

2) Quadriceps active test

3) Patellar apprehension test

4) External rotation recurvatum test

-What is the most appropriate treatment?

1) Delayed ligament reconstruction

2) Physical therapy and functional bracing

3) Immediate ligament repair

4) Immediate ligament reconstruction

-What is the most likely mechanism of injury?

1) External rotation

2) Posterior translation

3) Hyperextension and varus

4) Anterior translation and internal rotation

FOR QUESTIONS 56 THROUGH 58_
The MRI scan shows a bone bruise of the lateral femoral condyle and lateral tibial plateau. This injury pattern is commonly associated with anterior cruciate ligament (ACL) rupture and an abnormal pivot shift test result. Treatment of an ACL tear in a high-demand athlete should consist of ligament reconstruction.In this patient, surgery should be delayed until she regains full range of motion to minimize risk for arthrofibrosis after surgery. Recent analysis has shown that the noncontact mechanism is more consistent with anterior translation, affecting both the medial and lateral compartments. The bone bruise in the lateral femoral condyle occurs more anterior than that of the medial femoral condyle, suggesting that internal rotation has occurred. The external rotation recurvatum test assesses for posterolateral corner injury, and a positive quadriceps active test is consistent with posterior cruciate ligament rupture. An abnormal patellar apprehension test result is suggestive of patellar instability. Nonsurgical treatment is unlikely to result in sufficient stability if this patient returns to sports at her preinjury level of activity.Primary ACL repair is associated with high failure rates. Although the precise mechanism of injury varies,injuries can be broadly classified into contact and noncontact injuries. Noncontact injuries occur with the knee in slight flexion, valgus, and internal rotation, and contact injuries typically involve a lateralside impact producing a valgus force to the knee. The valgus component of noncontact injuries has been thought to cause mainly lateral compartment bone bruising. Posterior translation is the most common mechanism of posterior cruciate ligament rupture, and hyperextension and varus is associated with posterolateral corner injury.

-A 12-year-old boy who plays multiple sports has had insidious-onset heel pain while running for 4 months. On examination, he had ankle dorsiflexion of 5 degrees. The squeeze test result was positive and the Thompson test result was negative. He has no pain with forced ankle plantar flexion. What is the most likely diagnosis?

1) Achilles rupture

2) Gastrocnemius strain

3) Calcaneal apophysitis

4) Os trigonum syndrome

_CLINICAL SITUATION FOR QUESTIONS 60 AND 61_
A 15-year-old boy has had shoulder pain for 4 weeks during the middle of baseball season. The patient says his pain is “all over my shoulder.” Examination reveals tenderness to palpation over the anterolateral aspect of the shoulder. Internal and external rotation range of motion is restricted.
Radiographs show metaphyseal sclerosis.

-What is the most significant risk factor for the development of little leaguer’s shoulder in this scenario?

1) Recent increase in the number of pitches

2) Gender (male)

3) Glenohumeral internal rotation deficit

4) Genetic factors

-This boy’s parents are eager to get him back on the field as soon as possible. What is the most appropriate treatment option?

1) Screw fixation of the epiphysis

2) Arthroscopic debridement

3) A shut-down period until the boy is asymptomatic, and gradual return to pitching via a throwing program

4) An intra-articular cortisone injection

FOR QUESTIONS 60 AND 61_
Although a recent increase in the number of pitches may have contributed to this patient’s development of little leaguer’s shoulder, the most significant overall factor is age. Little leaguer’s shoulder is caused by rotational stress placed on the proximal humeral epiphysis during overhead throwing. The growth plate is weakest to torsion stress, and is most susceptible to injury during periods of rapid growth commonly seen during puberty. Most chronic shoulder injuries occur in throwing athletes between 13 and 16 years of age. Genetic factors and gender have not been studied in association with little leaguer’s shoulder. An initial 3-month period of rest and activity modification will typically result in resolution of symptoms.Nonsteroidal anti-inflammatory drugs may be used as needed. After the rest period, a gradual return to baseline pitching is implemented until the patient is back to baseline. This protocol has a long-term success rate exceeding 90%.

-is an arthroscopic view of the intercondylar notch of a right knee from an anterolateral portal.What is the main function of the structure delineated by the black asterisks?

1) Resist anterior translation during knee flexion

2) Resist posterior translation during knee flexion

3) Resist rotatory loads during knee flexion

4) Resist rotatory loads during knee extension

-A 25-year-old wrestler has been experiencing increasing left knee pain since his last professional cage fight. He complains of both pain and instability on the medial side of his left knee. Examination reveals a grade 3 Lachman and pseudolaxity with valgus stress. Dial test findings are normal. Radiographs show medial degenerative changes and 5 degrees of varus alignment. What is the most appropriate treatment?

1) Rehabilitation with vibration-platform weight-bearing squats

2) Anterior cruciate ligament (ACL) reconstruction with autograft bone-tendon-bone

3) High-tibial osteotomy (HTO)

4) HTO plus ACL reconstruction at the same time

-What is an example of cognitive rest after concussion?

1) Playing chess

2) Increasing reading

3) Working online

4) Limiting video games

_**CLINICAL SITUATION FOR QUESTIONS 65 THROUGH 67**_

Figure 65 is the radiograph of a 24-year-old man who had left knee pain after sustaining a twisting injury while playing Ultimate Frisbee. On examination, he had a large effusion with tenderness over the lateral joint line. Pivot shift testing results were positive. Prone dial testing results at 30 degrees and 90 degrees were negative. An MRI scan shows a tear of the anterior cruciate ligament (ACL).

-Based on the radiograph, the attachment for which structure has been disrupted?

1) Iliotibial band

2) Popliteus tendon

3) Lateral meniscus

4) Lateral capsular ligament

-Compared with a transtibial technique, what effect will drilling the femoral tunnel through the anteromedial portal have?

1) Produces a longer femoral tunnel

2) Improves visualization while drilling

3) Should be performed at 90 degrees of knee flexion

4) Allows for independent access to the anatomic femoral insertion

-The patient requests anatomic double-bundle ACL reconstruction. Compared with transtibial singlebundle ACL reconstruction, anatomic double-bundle ACL reconstruction is more likely to

1) restore improved knee kinematics.

2) allow for earlier return to sports.

3) result in better clinical outcomes scores.

4) be associated with lower surgery cost.

FOR QUESTIONS 65 THROUGH 67
The radiograph shows a Segond fracture, an avulsion fracture involving the lateral capsular ligament.
This radiographic finding has been associated with ACL rupture in 75% to 100% of cases. Drilling the femoral tunnel through the anteromedial portal allows for independent access to the native femoral attachment. Fiber orientation is more oblique than with a transtibial technique and more closely resembles that of the native ligament. Double-bundle reconstruction attempts to duplicate native ACL anatomy.Biomechanical studies have shown that double-bundle reconstruction more
closely reproduces normal knee kinematics; however, this technique does not offer a clear advantage in terms of clinical outcomes.The iliotibial band inserts onto Gerdy’s tubercle. The popliteus tendon originates from the lateral femoral condyle. The lateral meniscus attaches near the intercondylar eminence at the anterior and posterior meniscal roots. Recent advances in ACL reconstruction focus on restoring the native ACL anatomy.Studies have determined that a knee flexion angle of 110 degrees is optimal to avoid blowout of the back wall and injury to the lateral structures while drilling.
Femoral tunnel length is typically shorter than with a transtibial approach and decreases with higher-flexion angles. Double-bundle reconstruction is associated with higher surgical costs because of the need for additional fixation and, in the case of allograft reconstruction, a second graft.

-A 42-year-old man has increasing pain and, to a lesser extent, some occasional left knee instability.Several years earlier he sustained a noncontact twisting injury to his knee. He had some initial soreness and pain but was able to resume his normal activities while avoiding sports. On examination, the patient has medial joint line pain, a grade 2+ Lachman, and a slight varus thrust. His radiographs reveal mild-tomoderate medial compartment osteoarthritis with varus alignment. What surgical treatment strategy likely will alleviate his pain?

1) Distal femoral osteotomy

2) Unicompartmental knee replacement

3) High tibial osteotomy (HTO), lateral closing wedge

4) HTO, medial opening wedge with decreased tibial slope

_**RESPONSES FOR QUESTIONS 69 THROUGH 71**_

Many clinical studies to date show that the extent of arthritis is the most common variable that has the greatest influence on outcome. The success rate of allograft transplantation is significantly diminished in patients who have grade IV chondromalacia of the knee or notable flattening and general joint incongruity.
REFERENCES: Carter TR: Meniscal allograft transplantation. Sports Med Arthroscopy Rev 1999;7:51-63.
Garrett JC: Meniscal transplantation: A review of 43 cases with two- to seven-year follow-up. Sports Med Arthroscopy Rev 1993;2:164-167.
van Arkel ER, de Boer HH: Human meniscal transplantation: Preliminary results at 2- to 5-year follow-up. J Bone Joint Surg Br 1995;77:589-595.

Pseudohypoparathyroidism (AHO) - end-organ insensitivity; in AHO, germline mutation that leads to loss of function of Galpha S (GNAS1); causes end-organ resistance to PTH
1/. PHP - short stature, short metacarpals (4th and 5th), rounded facies a. Mental retardation, tetany
b. Sex-linked dominant
2/. Laboratory features a. Hypocalcemia
b. Hyperphopshatemia c. Normal PTH

Studies examining the impact of graded water debt have clearly shown that the magnitude of core temperature and heart rate increase accompanying work are proportional to the magnitude of water debt at the onset of exercise. Though added thermal burden from hot climates is a factor, it appears to be less significant.
REFERENCES: Latzka WA, Montain SJ: Water and electrolyte requirements for exercise. Clin Sports Med 1999;18:513-524.
Montain SJ, Sawka MN, Latzka WA, et al: Thermal and cardiovascular strain from hypohydration: Influence of exercise intensity. Int J Sports Med 1998;19:87-91.
Sawka MN, Young AJ, Francesconi RP, et al: Thermoregulatory and blood responses during exercise at graded hypohydration levels. J Appl Physiol 1985;59:1394-1401.

DISCUSSION: Biomechanical in vitro studies of double-row fixation of rotator cuff tears during cyclic loading and tensile loading to failure have demonstrated that double-row fixation results in a higher ultimate tensile load when compared to single-row fixation. Peak-to-peak elongation, stiffness, and conditioning
elongation for double-row fixation were all similar to single-row fixation. These initial findings, however, may or may not lead to improved clinical outcomes.
REFERENCES: Ma CB, Comerford L, Wilson J, et al: Biomechanical evaluation of arthroscopic rotator cuff repairs: Double-row compared with single-row fixation. J Bone Joint Surg Am 2006;88:403-410. Kim DH, El

Attrache NS, Tibone JE, et al: Biomechanical comparison of single-row versus double-row suture anchor technique for rotator cuff repair. Am J Sports Med 2006;34:407-414.

Patients with macrodactyly should be followed up yearly. Although the parents may be difficult, this is not a reason to stop seeing a patient. The other answers choices are incorrect because treatment would be too late.

The translation and shortening are not problems and the amount of angulation will easily remodel with this fracture. There is nothing to be gained from operative reduction.

Anteromedial displacement of the tibial tubercle unloads the distal and lateral facets of the patella and shifts the forces to the proximal and medial facets. Therefore, if findings indicate arthrosis predominately in the medial and proximal areas of the patella, this is considered a relative contraindication because it may accentuate arthritic symptoms.
REFERENCES: Fulkerson JP: Anteromedialization of the tibial tuberosity for patellofemoral malalignment. Clin Orthop 1983;177:176-181.
Bellemans J, Cauwenberghs F, Witvrouw E, et al: Anteromedial tibial tubercle transfer in patients with chronic anterior knee pain and a subluxation-type patellar malalignment. Am J Sports Med 1997;25:375-381.
Kuroda R, Kambic H, Valdevit A, et al: Articular cartilage contact pressure after tibial tuberosity transfer: A cadaveric study. Am J Sports Med 2001;29:403-409.

Figure C and Illustration A (below) demonstrate the radiographic "double-arc" finding.
McKee et al described a unique "shear fracture of the distal articular surface of the humerus" which involved coronal fractures of the capitellum and a portion of the trochlea. He described the characteristic radiographic finding as the "double-arc sign" which represents the subchondral bone of the displaced capitellum and lateral trochlea ridge.
Incorrect Answers:
Figure A shows a radial head fracture. Figure B shows an elbow dislocation.
Figure D shows a pediatric lateral condyle fracture.
Figure E shows a pediatric medial epicondyle apophyseal avulsion fracture.