AAOS Sports Medicine MCQs (Set 3): Knee Ligament Injuries & Shoulder Instability | ABOS Review

The MRI scans reveal a large posterior paralabral cyst associated with a posterior-superior labral tear. The cyst appears as a well-defined, smoothly marginated mass with low signal intensity on T1-weighted MRI scans and with high signal intensity on T2-weighted MRI scans. MRI also reveals changes in the supraspinatus and infraspinatus muscles secondary to denervation, including decreased muscle bulk and fatty infiltration. MRI has the added advantage, compared with other imaging modalities, of detecting intra-articular lesions, such as labral tears, which are frequently associated with ganglion cysts of the shoulder. In this case of a professional baseball player with a space-occupying lesion causing nerve compression with an associated labral tear, the treatment of choice is arthroscopic decompression of the cyst and repair of the tear. Acromioplasty would not address the primary pathology in this patient. Cummins CA, Messer TM, Nuber GW: Suprascapular nerve entrapment. J Bone Joint Surg Am 2000;82:415-424.

Federal courts have ruled that a student-athlete does not have a constitutional right to participate in athletics against medical advice. As long as the student retains his scholarship, the college is under no legal or ethical obligation to allow the student to participate in sports. A waiver would not hold up in court and would not indemnify the college or the team physician against suit. No equipment has been shown to be effective in preventing transient quadriplegia. Mathias MB: The competing demands of sport and health: An essay on the history of ethics in sports medicine. Clin Sports Med 2004;23:195-214.

Miller and associates reported the results of a cadaveric study of the vascular risk of a posterior approach for posterior cruciate ligament reconstruction using the tibial inlay technique. The average distance from the screw to the popliteal artery was 21.1 mm (range, 18.1 mm to 31.7 mm). Other approaches, such as the transtibial tunnel technique which involves drilling an anterior-posterior tunnel, have also been studied in cadavers. Matava and associates noted that increasing flexion reduces but does not completely eliminate the risk of arterial injury during arthroscopic posterior cruciate ligament reconstruction. However, this study did not use the small, medial utility incision recommended by Fanelli and associates, which creates an interval for the surgeon's finger between the medial gastrocnemius and the posteromedial capsule so that any migration of the guidepin can be palpated and changed prior to any injury to the posterior neurovascular bundle. Matava MJ, Sethi NS, Totty WG: Proximity of the posterior cruciate ligament insertion to the popliteal artery as a function of the knee flexion angle: Implications for posterior cruciate ligament reconstruction. Arthroscopy 2000;16:796-804. Miller MD, Kline AJ, Gonzales J, et al: Vascular risk associated with posterior approach for posterior cruciate ligament reconstruction using the tibial inlay technique. J Knee Surg 2002;15:137-140.

Cadaveric studies have shown that external rotation of the tibia is most pronounced following transection of the posterior cruciate and lateral collateral ligaments with the knee at 90 degrees of flexion. Isolated release of the lateral collateral ligament results in increased external tibial rotation at 30 degrees. Gollehon DL, Torzilli PA, Warren RF: The role of the posterolateral and cruciate ligaments in the stability of the human knee: A biomechanical study. J Bone Joint Surg Am 1987;69:233-242. Cooper DE: Tests for posterolateral instability of the knee in normal subjects: Results of examination under anesthesia. J Bone Joint Surg Am 1991;73:30-36.

The imaging studies reveal findings typical of the os trigonum syndrome. This condition results from inflammation between the os trigonum and the adjacent talus. The symptoms of posterior ankle pain are exacerbated by plantar flexion, which stresses the fibrous union between these two bones. Definitive management of the high-level athlete involves excision of the os trigonum from a medial approach, although arthroscopic excision has also been described. The os trigonum is not an intra-articular structure; therefore, ankle arthroscopy is neither diagnostic nor therapeutic. Abramowitz Y, Wollstein R, Barzilay Y, et al: Outcome of resection of a symptomatic os trigonum. J Bone Joint Surg Am 2003;85:1051-1057. Mouhsine E, Crevoisier X, Leyvraz P, et al: Post-traumatic overload or acute syndrome of the os trigonum: A possible cause of posterior ankle impingement. Knee Surg Sports Traumatol Arthrosc 2004;12:250-253.

Injuries to the MCL usually result from repetitive high valgus stress on the medial aspect of the elbow joint due to overhead throwing or racquet sports. Excessive stresses during the late cocking and acceleration phase of throwing can injure the anterior band of the MCL. Clinically, the injuries may present as chronic or acute, and a pop may be noted in the latter. Associated ulnar nerve involvement is common. Valgus instability is present in about 25% of patients. Patients typically are athletes who participate in throwing and have localized medial elbow pain and tenderness along the course of a ligament that extends from the medial epicondyle of the distal humerus to the sublime tubercle of the ulna. Surgical reconstruction is the procedure of choice in an athlete desiring a return to a high level of throwing. Miller MD, Cooper DE, Warner JJP (eds): Review of Sports Medicine and Arthroscopy. Philadelphia, PA, WB Saunders, 1995, p 230. Arendt EA (ed): Orthopaedic Knowledge Update: Sports Medicine 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, p 227.

There is almost universal acceptance that an athlete may return to play after blunt head trauma only if he or she is totally asymptomatic. Mild residual symptoms are considered an absolute contraindication for return to play. Returning to play after a cardiovascular challenge or sport-specific activities is permitted on the pretext that the athlete is totally asymptomatic prior to these maneuvers. Neuropsychiatric testing is being used more frequently to monitor residual cognitive effects after head trauma. It has not been used as a return to play criterion. Garrick J (ed): Orthopaedic Knowledge Update: Sports Medicine 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004, pp 29-48.

Proper hydration prior to an athletic event is the most important determinant of performance. It is virtually impossible to keep pace with fluid loss during an athletic competition. When a net loss of fluid occurs and the athlete is properly prehydrated, this fluid loss will not adversely affect performance. It is not necessary to load up on carbohydrates prior to a 10K race, or to replace calories burned during the race. Hyponatremia can develop in ultra-endurance athletes, especially marathoners, if they hydrate without replacing electrolytes lost through sweating; however, this is highly unlikely for a 10K race. Newmark SR, Toppo FR, Adams G: Fluid and electrolyte replacement in the ultramarathon runner. Am J Sports Med 1991;19:389-391.

The MRI scan shows a dislocated peroneus brevis tendon with disruption of the peroneal retinaculum. This injury is commonly seen in skiers and is the result of peroneal contraction with the ankle everted and dorsiflexed. Nonsurgical management is rarely successful; therefore, repair of the peroneal retinaculum is the treatment of choice. Eckert WR, Davis EA Jr: Acute rupture of the peroneal retinaculum. J Bone Joint Surg Am 1976;58:670-672. Murr S: Dislocation of the peroneal tendons with marginal fracture of the lateral malleolus. J Bone Joint Surg Br 1961;43:563-565.

Nonsurgical management is considered for proximal tears as well as partial tears in some individuals. Surgical management is often not appropriate in older or sedentary patients. However, patients treated nonsurgically will have a significant cosmetic defect, as well as weakness in adduction and internal rotation. Schepsis AA, Grafe MW, Jones HP, et al: Rupture of the pectoralis major muscle: Outcome or repair of acute and chronic injuries: Am J Sports Med 2000;28:9-15.

Coxa saltans (snapping hip syndrome) can occur in two forms: external/lateral or interior/medial/anterior. This patient has the external/lateral form. The external/lateral form involves the iliotibial band, tensor fascia, or gluteus medius, which snaps over the greater trochanter. The external form usually can be treated with physical therapy alone; however, several recent studies report satisfactory results with surgical treatment. Faraj and associates reported good results from surgical Z-plasty in a series of 10 patients. White and associates reported good results in a series of 16 patients with 17 hips who underwent surgical release of an external snapping hip. The interior/medial/anterior form can involve the iliopsoas tendon, acetabular labrum, subluxation of the hip, and loose bodies. White RA, Hughes MS, Burd T, et al: A new operative approach in the correction of external coxa saltans: The snapping hip. Am J Sports Med 2004;32:1504-1508. Faraj AA, Moulton A, Sirivastava VM: Snapping iliotibial band: Report of ten cases and review of the literature. Acta Orthop Belg 2001;67:19-23.

Low dose gamma irradiation (less than 3.0 megarads) with antibiotic soaks is one of the most common techniques for secondary sterilization. Elimination of HIV with gamma irradiation requires doses estimated to be greater than 3.5 megarads. Gamma irradiation levels of 4 megarads have been shown to alter the mechanical properties of human infrapatellar tendons. Ethylene oxide, also used for allograft sterilization, has been associated with a chronic inflammatory process that resolved after graft removal. Jackson DW, Windler GE, Simon TM: Intraarticular reaction associated with the use of freeze-dried, ethylene oxide-sterilized bone-patella tendon-bone allografts in the reconstruction of the anterior cruciate ligament. Am J Sports Med 1990;18:1-10. Conway B, Tomford W, Mankin HJ, et al: Radiosensitivity of HIV-1: Potential application to sterilization of bone allografts. AIDS 1991;5:608-609.

Ganglia involving the cruciate ligaments have been recently reported as a cause of knee pain that interferes with knee flexion and extension. The symptoms are poorly localized in this patient and not along the medial joint line, making the diagnosis of a torn medial meniscus less likely. In addition, the MRI findings do not show a significant medial meniscal lesion. A Baker's cyst is usually posteromedial and extends posterior to the interval between the medial head of the gastrocnemius and semimembranosus. MRI scans show a fluid-filled lesion with an increased signal on T1- and T2-weighted images. A lipoma would be bright on the T1-weighted image only. Deutsch A, Veltri DM, Altchek DW, et al: Symptomatic intraarticular ganglia of the cruciate ligaments of the knee. Arthroscopy 1994;10:219-223.

The imaging study demonstrates characteristics of Little Leaguer's shoulder, including physeal widening. This condition is secondary to overuse (typically throwing) and responds well to rest from the inciting activity. There is no evidence from the patient's history or examination that he has an impingement syndrome, nor is there any indication of labral pathology on the MRI scan. The changes in the proximal humerus are classic for this condition and are not suggestive of a neoplastic process requiring biopsy for definitive diagnosis. Lipscomb AB: Baseball pitching injuries in growing athletes. J Sports Med 1975;3:25-34. Cahill BR, Tullos HS, Fain RH: Little league shoulder: Lesions of the proximal humeral epiphyseal plate. J Sports Med 1974;2:150-152.

The patient has chronic posterolateral instability with a varus knee alignment; therefore, the most effective treatment is a valgus-producing HTO. A repeat soft-tissue reconstruction without correction of the varus alignment will most likely fail. An ACL reconstruction is not indicated with a normal Lachman's test. Physical therapy and bracing will have little effect. Naudie DD, Amendola A, Fowler PJ: Opening wedge high tibial osteotomy for symptomatic hyperextension-varus thrust. Am J Sports Med 2004;32:60-70.

Avulsion of the terminal extensor tendon from the distal phalanx (mallet or baseball finger) may or may not be associated with a bony avulsion. The injury is caused by forcible flexion of the DIP joint while catching a ball or hitting an object with the finger extended. Most authorities recommend continuous extension splinting to the DIP joint for 6 weeks, followed by nighttime splinting for an additional 6 weeks. It must be emphasized to the patient that at no time during the initial 6 weeks of treatment should the DIP joint be allowed to fall into flexion or an additional 6 weeks of continuous splinting is required. Miller MD, Cooper DE, Warner JP (eds): Review of Sports Medicine and Arthroscopy. Philadelphia, PA, WB Saunders, 1995, p 255. Rettig AC: Closed tendon injuries of the hand and wrist in the athlete. Clin Sports Med 1992;11:77-99.

Rehabilitation of the quadriceps muscle following a partial tear of the PCL has been associated with a favorable outcome. The quadriceps acts an antagonist to the PCL because its contraction results in anterior tibial translation, which reduces the tensile stress on the injured ligament. Strengthening of the hamstring musculature increases posterior tibial translation and is contraindicated during the early rehabilitative phase following a PCL injury. Brace use has not been found to significantly alter the outcome following nonsurgical management of PCL tears. Parolie JM, Bergfeld JA: Long-term results of nonoperative treatment of isolated posterior cruciate ligament injuries in the athlete. Am J Sports Med 1986;14:35-38.

When you are employed as a team physician, you are obligated to inform the players and the team organization of all athletically relevant medical issues. This differs significantly from the normal rule of patient confidentiality. If the player came to see you and you were not the team physician, you may not inform the team unless the player so desires. As the team physician, you are not obligated to inform the media. Tucker AM: Ethics and the professional team physician. Clin Sports Med 2004;23:227-241.

Sports hernias may be one of the most common causes of groin pain in athletes. Resisted hip adduction is painful in the case of groin disruption. Radiation of pain into the testicles and/or adductor region is often present. Sports hernias are associated with weakening of the posterior inguinal wall. In contrast with sports hernias, traditional or classic hernias can be readily detected on physical examination. Diagnostic imaging studies are not helpful and only serve to help exclude other diagnoses. Systemic high-dose steroids or sacroiliac joint injections have no role in treatment. High success rates have been reported for laparoscopic hernia repair in athletes. Kluin J, den Hoed PT, van Linschoten R, et al: Endoscopic evaluation and treatment of groin pain in the athlete. Am J Sports Med 2004;32:944-949. Genitsaris M, Goulimaris I, Sikas N: Laparoscopic repair of groin pain in athletes. Am J Sports Med 2004;32:1238-1242.

The patient has sustained an iatrogenic injury to the lateral ulnar collateral ligament. This injury has been reported after lateral approaches to the elbow. The orbicular, annular, and lateral radial collateral ligaments have a much less important role in lateral elbow stability. The anterior band of the ulnar collateral ligament is on the medial side of the elbow and is important for valgus stability. O'Driscoll SW, Bell DF, Morrey BF: Posterolateral rotatory instability of the elbow. J Bone Joint Surg Am 1991;73:440-446.

Stress fractures in female long distance runners are frequently associated with the Female Athletic Triad. The triad consists of osteoporosis, amenorrhea, and altered eating habits. A thorough menstrual history, including age of menarche, history of amenorrhea, and use of oral contraceptives, is imperative. Amenorrhea leads to osteoporosis and predisposes the athlete to fractures. An MRI of the hip is not necessary because a fracture is evident on the radiograph. Serum calcium levels are normal in osteoporosis, a family history would be noncontributory, and it is highly unlikely that a contralateral hip radiograph will yield useful information. Bennell KL, Malcolm SA, Thomas SA, et al: Risk factors for stress fractures in track and field athletes: A twelve-month prospective study. Am J Sports Med 1996;24:810-818.

Stress fractures of the navicular are often seen in running and jumping sports. Whereas most individuals heal with nonsurgical management consisting of 6 weeks of casting, this gymnast has had pain for 1 year and nonsurgical management has failed. Open reduction with bone grafting is the preferred treatment. Quirk RM: Stress fractures of the navicular. Foot Ankle Int 1998;19:494-496.

There is a spectrum of heat-related conditions. Heat cramps are the mildest form of heat illness. In heat exhaustion, cramps are associated with headache and weakness, and the skin is pale and moist. Treatment of heat cramps or heat exhaustion consists of removing and loosening excess clothing, applying ice to the axilla and groin, ingestion of cool water, and cool water sprays. This patient demonstrates symptoms of heat stroke which is a medical emergency. The core body temperature may be as high as 106 to 110 degrees F (41.1 to 43.3 degrees C). In heat stroke, the patient may no longer be sweating, and the skin may be hot and red. The athlete is usually confused, weak, nauseated, and may have seizure activity. Central nervous system depression has been called the most important marker of heat stroke, and progresses from confusion and bizarre behavior to collapse, delirium, and coma. Bizarre behavior is often the first sign of heat stroke. The patient needs to be treated and moved to a medical facility rapidly. During transfer, IV fluids and cooling of the athlete should be initiated. The best treatment of heat-related illness appears to be prevention with adequate hydration and monitoring of conditions (temperature and humidity), with cancellation of competition when conditions do not comply with guidelines. Griffin LY: Emergency preparedness: Things to consider before the game starts. J Bone Joint Surg Am 2005;87:894-902. Barker TA, Motz HA, Gersoff WK: Environmental factors in athletic performance, in Fu FH, Stone DA (eds): Sports Injuries, ed 2. Philadelphia, PA, Lippincott, 2001, pp 67-68.

Ford and associates studied 81 high school basketball players and found that females landed with greater total valgus knee loading and a greater maximum valgus knee angle than male athletes. Hewett and associates reported in a study of 205 female athletes that those with increased dynamic valgus and high abduction loads were at increased risk of anterior cruciate ligament injury. Hewett TE, Myer GD, Ford KR, et al: Biomechanical measures of neuromuscular control and valgus loading of the knee predict anterior cruciate ligament injury risk in female athletes: A prospective study. Am J Sports Med 2005;33:492-501.

Insufficient caloric intake caused by either a poor diet or an eating disorder is the most common cause for the loss of menses in a female athlete. In the face of adequate caloric intake, stress is unlikely to cause amenorrhea. Oral contraceptives control menses but do not eliminate it. Diabetes mellitus does not cause the new onset of amenorrhea. Pregnancy can be a cause in a sexually active athlete. Chromosomal abnormalities can result in delayed or absent menarche but not the onset of amenorrhea in a postmenarchal female. Constantini NW: Clinical consequences of amenorrhea. Sports Med 1994;17:213-223.