AAOS Sports Medicine Board Review (Set 2): Knee, Shoulder & Ankle Injuries

Closed kinetic chain exercises are used early in the rehabilitation process. The distal segment is fixed, and an axial load is applied which provides glenohumeral compression and reduces the demand on the rotator cuff. These exercises stimulate co-contractions of the scapular and rotator cuff muscles, load scapular stabilizers, and facilitate active motion. Facilitated active motion exercises use proximal segment motion to stimulate and facilitate motion in the target tissue. These exercises are often performed in diagonal movements. Resistive active motion exercises are used later in the rehabilitation process. These are typically open kinetic chain exercises that involve active glenohumeral motion with extrinsic loads such as weights or exercise tubing. During the later stages of upper extremity rehabilitation, plyometrics are added. These exercises help to prepare the athlete for return to sport. When performed at slower speeds, these exercises emphasize stabilization and control. As the speeds increase, muscles begin to work in the stretch-shortening sequence associated with sports participation. Garrick JG (ed): Orthopaedic Knowledge Update: Sports Medicine 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004, pp 129-136.

Hypertrophic cardiomyopathy (HCM) accounts for up to 50% of cases of sudden death in young athletes. HCM phenotype becomes evident by age 13 to 14 years. Those at higher risk include individuals with cardiac symptoms, a family history of inherited cardiac disease, and those with a family history of premature sudden death. Echocardiography is useful for detecting structural heart disease, including the cardiomyopathies and valvular abnormalities. Trained adolescent athletes demonstrated greater absolute left ventricular wall thickness (LVWT) compared to controls. HCM should be considered in any trained adolescent male athlete with a LVWT of more than 12 mm (female of more than 11 mm) and a nondilated ventricle. Adolescent and adult athletes differ with respect to the range of LVWT measurements, as a manifestation of left ventricular hypertrophy (LVH). Differentiating LVH ("athlete's heart") from HCM involves looking at additional echocardiographic features. Sharma and associates reported that adolescents with HCM had a small or normal-sized left ventricle (less than 48 mm) chamber size, while those with LVH had a chamber size at the upper limits of normal (52 mm to 60 mm). Sharma S, Maron BJ, Whyte G, et al: Physiologic limits of left ventricular hypertrophy in elite junior athletes: Relevance to differential diagnosis of athlete's heart and hypertrophic cardiomyopathy. J Am College Cardiol 2002;40:1431-1436. Maron BJ, Spirito P, Wesley Y, et al: Development and progression of left ventricular hypertrophy in children with hypertrophic cardiomyopathy. N Engl J Med 1986;315:610-614.

The MRI scans reveal a severe avulsion injury of the adductor muscle from the pubic ramus with muscle edema and hemorrhage. Injury to the adductor muscle group, a "pulled groin," is caused by forceful external rotation of an abducted leg. Pain is immediate and severe in the groin region. Tenderness is at the site of injury along the subcutaneous border of the pubic ramus. Treatment is dictated by the severity of the symptoms but generally consists of rest, ice, and protected weight bearing, followed by a rehabilitation program that begins with gentle stretching and progresses to resistance exercise with a gradual return to sports. Immobilization should be avoided because this promotes muscle tightness and scarring. No data exist to suggest that open repair yields a better outcome than nonsurgical management. Tenotomy has been performed in high-level athletes with chronic groin pain following injury. Gilmore J: Groin pain in the soccer athlete: Fact, fiction, and treatment. Clin Sports Med 1998;17:787-793.

The athlete has symptoms referable to the axillary, musculocutaneous, and suprascapular nerves resulting from an injury to the upper trunk of the brachial plexus. This portion of the plexus is formed by contributions of the fourth through sixth cervical nerve roots. This area is often contused or stretched following a tackling maneuver that results in either depression of the shoulder from contact at Erb's point or traction of the upper plexus from forced stretching of the neck to the contralateral side. Schenck CD: Anatomy of the innervation of the upper extremity, in Torg JS (ed): Athletic Injuries to the Head, Neck, and Face, ed 2. St Louis, MO, Mosby-Year Book, 1991.

Horseback riding is a sport that directly affects the jockey's spine. Tsirikos and associates reported the results of a study of 32 jockeys. They found that equestrian sports, especially professional horseback riding, apart from the increased risk of direct spinal injury caused by a fall from the horse, can lead to progressive spinal degeneration as a result of repetitive trauma and increased physical stress on the spine. It is associated with spondylosis of the cervical spine and lumbar spine. Tsirikos A, Papagelopoulos PJ, Giannakopoulos PN, et al: Degenerative spondyloarthropathy of the cervical and lumbar spine in jockeys. Orthop 2001;24:561-564.

Infectious mononucleosis commonly affects adolescents and young adults. It is a febrile illness accompanied by acute pharyngitis. Splenomegaly may occur and predispose the athlete to splenic rupture. Splenic rupture has been reported in nonathletes as well as in patients with normal-sized spleens. Clinical evidence supports a return to all sports 4 weeks after the onset of symptoms provided that the spleen has returned to normal size. Auwaerter PG: Infectious mononucleosis: Return to play. Clin Sports Med 2004;23:485-497.

Microfracture is a marrow stimulation technique where stem cells from the underlying subchondral bone marrow can form at the base of the lesion. The rationale for this technique is based on these cells differentiating into cells that will produce an articular cartilage repair. Biopsy findings in animals and humans have demonstrated primarily a fibrocartilagenous repair tissue and not articular cartilage. The collagen type found in hyaline or articular cartilage is of the type II variety. Fibrocartilage possesses mostly type I and III cartilage. Buckwalter JA, Mankin HJ: Articular cartilage: Degeneration and osteoarthritis, repair, regeneration, and transplantation. Instr Course Lect 1998;47:487-504.

Flexor hallucis longus tendinitis is a common cause of posterior ankle pain in dancers. It tends to be more posteromedial and is characterized by a clicking or catching sensation posteromedially with motion of the great toe. A painful os trigonum typically causes more posterolateral ankle pain and may occur after an ankle sprain or plantar flexion injury where there may be a fracture of the os trigonum. Garrick JG (ed): Orthopaedic Knowledge Update: Sports Medicine 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004, pp 249-261.

Kinematic analysis of both menisci demonstrates anterior movement with extension and posterior movement with flexion. The lateral meniscus has more mobility than the medial meniscus because of less soft-tissue attachments. Insall JN, Scott WN (eds): Surgery of the Knee, ed 3. New York, NY, Churchill Livingstone, 2001, vol 1, p 474. Thompson WO, Thaete FL, Fu FH, et al: Tibial meniscal dynamics using 3D reconstructions of MR images, in Proceedings of the Orthopaedic Research Society 1990;389.

The imaging studies reveal a navicular stress fracture. This condition is secondary to chronic overuse (often running on hard surfaces) and results in vague, ill-defined pain in the midfoot. These fractures can be missed on radiographs but are well-defined on CT or MRI. Tarsal navicular fractures are typically oriented in the sagittal plane. Surgery is typically indicated for the high-level athlete because of the high risk for nonunion and persistent symptoms following nonsurgical management. Internal fixation is the treatment of choice. Torg JS, Pavlov H, Cooley JH, et al: Stress fractures of the tarsal navicular. J Bone Joint Surg Am 1982;64:700-712.

The player's symptoms represent more than the mere "burner syndrome," which leads to unilateral symptoms that typically last less than 1 minute. Return to play following a burner is allowed following nonsurgical management and once the symptoms have subsided and the player exhibits normal strength and motion of the neck and upper extremities. This player has the history, symptoms, and examination findings that are consistent with cervical neurapraxia. Return to play in contact sports is contraindicated with bilateral symptoms prior to MRI evaluation of the cervical spine. CT of the brain is indicated with a history of loss of consciousness or other symptoms suggestive of a concussion. Torg JS, Sennett B, Pavlov H, et al: Spear tackler's spine: An entity precluding participation in tackle football and collision activities that expose the cervical spine to axial energy inputs. Am J Sports Med 1993;21:640-649. Torg JS: Cervical spinal stenosis with cord neurapraxia and transient quadriplegia. Sports Med 1995;20:429-434.

Age of menarche is the most accurate clinical factor to assess the degree of skeletal maturity in the female athlete. Such an assessment is necessary prior to ACL reconstruction in a skeletally immature female because of the risk of damage to the distal femoral and proximal tibial physes. Height of an older male sibling is not relevant to the female athlete. Parental height and recent change in shoe size are only moderately useful in predicting final growth, and hence, skeletal maturity. The presence of breast buds occurs early in adolescent development; therefore, its presence suggests a high likelihood of future growth. Micheli LJ, Foster TE: Acute knee injuries in the immature athlete. Instr Course Lect 1993;42:473-481. Stanitski CL: Anterior cruciate ligament injury in the skeletally immature patient: Diagnosis and treatment. J Am Acad Orthop Surg 1995;3:146-158.

When considering the diagnosis of scapholunate ligament injury, standard radiographic views of the hand will not always reveal widening of the scapholunate gap. Although MRI may reveal injury to the ligaments, the PA clenched fist view can be obtained in the office during the initial patient visit. Arthroscopy is not a first-line diagnostic tool. Walsh JJ, Berger RA, Cooney WP: Current status of scapholunate interosseous ligament injuries. J Am Acad Orthop Surg 2002;10:32-42.

The MRI scan reveals a partial patellar tendon rupture in conjunction with chronic patellar tendinitis. Mild and moderate patellar tendinitis may be treated nonsurgically with rest, stretching, strengthening, and anti-inflammatory drugs. Severe tendinopathy or extensor mechanism disruption is best treated surgically with tendon debridement and repair. Al-Duri ZA, Aichroth PM: Surgical aspects of patella tendonitis: Techniques and results. Am J Knee Surg 2001;14:43-50.

Hook of the hamate fractures typically occur as a result of direct force from swinging a bat, golf club, or racket. Pain is localized to the hypothenar eminence. The injury is best seen on a carpal tunnel view. CT will confirm the diagnosis. Chronic cases can be associated with neuropathy of the ulnar nerve. Excision of the hook through the fracture site usually yields satisfactory results, allowing the athlete to return to competition. Parker RD, Berkowitz MS, Brahms MA, et al: Hook of the hamate fractures in athletes. Am J Sports Med 1986;14:517-523.

A Jones fracture occurs at the metaphyseal-diaphyseal junction of the fifth metatarsal. It is often an acute fracture in conjunction with a chronic stress-related injury. It requires either a short leg cast with strict non-weight-bearing or surgical fixation. In the high performance athlete, the need for rapid return to sport activity usually requires surgical intervention, most commonly with an intramedullary screw. Brodsky JW, Krause JO: Stress fractures of the foot and ankle, in Delee JC, Drez D (eds): Orthopaedic Sports Medicine, ed 2. Philadelphia, PA, Saunders, 2003, vol 2, pp 2391-2409.

Anterior superior iliac spine avulsion fractures are caused by sudden, forceful contractions of the sartorius and tensor fascia lata. These injuries occur in young athletes through the growth plate with the hip extended and the knee flexed, such as while sprinting or swinging a baseball bat. The athlete will often report a pop or snap at the time of injury. Displaced fractures usually can be seen on radiographs. CT or MRI can be obtained to confirm the diagnosis. In most patients, nonsurgical management consisting of rest and protected weight bearing yields satisfactory outcomes. Surgery is usually reserved for fractures with displacement of more than 3 cm and painful nonunions. Garrick JG (ed): Orthopaedic Knowledge Update: Sports Medicine 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004, pp 139-153.

Heat stroke consists of hyperthermia (greater than 105.8 degrees F [41 degrees C]), central nervous system dysfunction, and cessation of sweating with hot, dry skin. It is a medical emergency that results from failure of the thermoregulatory mechanisms of the body. It has a high death rate and requires rapid reduction in body core temperature. Heat syncope is characterized by a transient loss of consciousness with peripheral vasodilation and decreased cardiac output with normal body temperature. Heat cramps involve painful contractions of large muscle groups because of decreased hydration and a decrease of serum sodium and chloride. Heat exhaustion is distinguished by a core temperature of less than 102.2 degrees F (39 degrees C) and an absence of central nervous system dysfunction. Hypernatremic heat exhaustion results from inadequate water replacement. Knochel JP: Environmental heat illness: An eclectic review. Arch Intern Med 1974;133:841-864. Hubbard RW, Gaffin SL, Squire DL: Heat related illness, in Wilderness Medicine, ed 3. St Louis, MO, Mosby, 1995, p 167.

Success of a meniscal allograft transplantation is strongly dependent on accurate graft sizing, typically within 5% of the native meniscus. Previous studies have established that donor cell viability is not mandatory for the survival of these grafts since they are replaced by the recipient's cells (at least peripherally) within several weeks. Thus, cryopreservation of the graft to ensure cell viability is not necessary. There is a limited immune response to musculoskeletal allografts; therefore, immunosuppression, as is required for visceral organ transplantation, is not indicated. Wirth CA, Kohn D: Meniscal transplantation and replacement, in Fu FH, Harner CD, Vince JG (eds): Knee Surgery. Baltimore, MD, Williams & Wilkins, 1994, vol 1, pp 631-641. Brautigan BE, Johnson DL, Caborn DM, et al: Allograft tissues, in Drez D, DeLee JD, Miller MD (eds): Orthopaedic Sports Medicine: Principles and Practice, ed 2. Philadelphia, PA, WB Saunders, 2003, pp 205-213.

Users of anabolic steroids often display increased feelings of hostility and aggression. Although reports of psychotic, depressive, and manic behavior have been reported with the use of steroids, they are rare. Drug dependence, such as seen with narcotics, is not a feature of steroid use. Hartgens F, Kuipers H: Effects of androgenic-anabolic steroids in athletes. Sports Med 2004;34:513-554.

Endoscopic ACL reconstructive techniques may result in a vertical graft placement. The reconstructed ligament will resist anterior translation of the tibia but the graft will not restore rotatory stability. Decreased flexion and extension are caused by placement of the femoral tunnel too anterior and posterior, respectively. Impingement of the graft on the femoral notch is caused by anterior placement of the tibial tunnel or inadequate notchplasty. Scopp JM, Jasper LE, Belkoff SM, et al: The effect of oblique femoral tunnel placement on rotational constraint of the knee reconstructed using patellar tendon autografts. Arthroscopy 2004;20:294-299.

Several cutting studies have evaluated the primary static restraints and the role of the glenohumeral ligaments in providing static stability. With the arm at the side in adduction, the superior glenohumeral ligament and coracohumeral ligament are the primary restraints to inferior translation. The middle glenohumeral ligament functions with the arm in 45 degrees of abduction and resists anterior translation. The inferior glenohumeral ligament is the primary restraint to anterior translation at 90 degrees of abduction. Warner JJ, Deng XH, Warren RF, et al: Static capsuloligamentous restraints to superior-inferior translation of the glenohumeral joint. Am J Sports Med 1992;20:675-685.

Carbohydrate loading is the practice of maximizing glycogen stores by decreasing training and increasing carbohydrate intake the week before an endurance event. Nonendurance athletes do not benefit from this because glycogen depletion is not the limiting factor during a normal competition. Potential side effects of carbohydrate loading are water retention, muscle stiffness, and weight gain. Coyle EF, Hagberg JM, Hurley BF, et al: Carbohydrate feeding during prolonged strenuous exercise can delay fatigue. J Appl Physiol 1983;55:230-235. Costill DL, Sherman WM, Fink WJ, et al: The role of dietary carbohydrates in muscle glycogen resynthesis after strenuous running. Am J Clin Nutr 1981;34:1831-1836.

Type V acromioclavicular dislocations are characterized by elevation of the clavicle of 100% to 300% and involve extensive soft-tissue stripping. The treatment of choice is surgical reduction of the acromioclavicular joint and some type of stabilization. Treatment of type III injuries is controversial. Lemos MJ: The evaluation and treatment of the injured acromioclavicular joint in athletes. Am J Sports Med 1998;26:137-144.

Both the medial collateral ligament and the olecranon contribute to valgus stability of the elbow. Excessive olecranon resection increases the demand placed on the medial collateral ligament in resisting valgus forces during throwing. Bone removal from the olecranon should be limited to osteophytes. Garrick JG (ed): Orthopaedic Knowledge Update: Sports Medicine 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004, pp 101-111.