Acromioclavicular Separation

The AC joint is composed of the acromion of the scapula and the distal clavicle. The AC and coracoclavicular ligaments stabilize the joint (see Figure 25-1). AC joint injuries, including sprains, subluxations and dislocations, are referred to as shoulder separations and account for 10% of all shoulder injuries. Injury to the AC joint is usually caused by a fall onto the top of the shoulder, causing the scapula and acromion to be pushed inferiorly, and the clavicle, with its medial end attached to the sternum, to be elevated. AC separations have a 5 : 1 male-to-female ratio and are encountered most frequently in hockey, wrestling, and the martial arts. Examination reveals asymmetric enlargement of the AC joint with localized tenderness to the joint. Forward flexion, extension, and cross-chest adduction results in AC joint pain. Diagnosis is made clinically or by plain radiographs dedicated to the AC joint. Milder separations are typically treated nonoperatively with rehabilitation, and the far less common severe separations may require surgical repair.

Anterior Shoulder Dislocation

Anterior dislocation of the glenohumeral joint accounts for 90% of shoulder dislocations. Common mechanisms are falling onto an outstretched hand with a straight arm or making contact with another player with the shoulder abducted to 90 degrees and forcefully rotated externally. These patients experience the sudden onset of pain, a “pop,” and an inability to use the arm. This diagnosis is uncommon in pediatric athletes younger than 10 years of age; a shoulder deformity in younger patients often represents a proximal humeral fracture rather than an acute glenohumeral dislocation.

Examination reveals flattening of the deltoid prominence, prominence of the acromion, fullness of the subcoracoid region, and downward displacement of the axillary fold (Figure 25-2). It is also important to test for axillary and musculocutaneous nerve injury (see Figure 25-2).

Figure 25-2 Anterior dislocation of glenohumeral joint.

Evaluation requires axillary, anteroposterior (AP), and scapular Y radiographs both before and after reduction to rule out associated fracture. An acute glenohumeral joint dislocation is an orthopedic emergency and requires closed reduction. There are many techniques for closed reduction; two of the more common are the traction–countertraction technique and Stimson’s maneuver (see Figure 25-2). It is important to reexamine the neurovascular integrity of the arm after reduction. Surgical reduction is rarely indicated. After reduction, the arm is immobilized for 2 to 4 weeks followed by gradual rehabilitation. Up to 90% of patients with shoulder dislocations before age 20 years have a recurrence.

Elbow Dislocation

The elbow is the most commonly dislocated joint in children. Posterior dislocations are more common because of the shape of the olecranon process. They occur in older children, whose physes have closed, after falling backward onto an outstretched hand with the shoulder abducted. Simple dislocations can be seen in conjunction with associated fractures. On examination, an obvious deformity is noted, with the olecranon process displaced prominently behind the distal humerus (Figure 25-3). A careful neurovascular examination must be performed before and after reduction, paying particular attention to the median nerve. AP and lateral radiographs are useful in diagnosis. Isolated dislocation is treated by closed reduction. Unlike a shoulder dislocation, the greatest risk for an elbow dislocation is stiffness rather than recurrence. For this reason, immobilization is required for a short period of time, and return to full use is closely supervised.

Figure 25-3 Elbow dislocation.

Elbow Overuse Injuries

“Little League elbow” is a broad term for several different elbow problems. Medial elbow pain is a common complaint of overhand throwers caused by repeated valgus stress on the joint, which can be exacerbated by improper throwing mechanics. In preadolescents, traction apophysitis of the medial epicondyle is most likely. Patients have tenderness along the medial epicondyle that is aggravated by resisted wrist flexion. Treatment includes restricting throwing for 4 to 6 weeks, pain-free strengthening, and gradual reintroduction of throwing with proper instruction.

In an adolescent athlete with medial elbow pain, avulsion fracture of the medial epicondyle must be considered. These can typically be treated with immobilization, but avulsions with significant displacement or neurovascular compromise often require surgical intervention. In young adults with a fused growth plate, ulnar collateral ligament tears are more common.

Lateral epicondylitis, or “tennis elbow,” is caused by repetitive contraction of the extensor muscles at their origin on the lateral epicondyle. Tenderness is elicited over the lateral epicondyle, and pain is felt with passive wrist flexion and resisted wrist extension. Initial treatment includes conservative therapy, rehabilitation, and limitation of activity.

Avulsion Fractures

Avulsion fractures occur because of a sudden contraction of a muscle pulling on a developing apophysis and are commonly seen in sports such as soccer, ice hockey, gymnastics, and sprinting. The combination of intensive training at an inherently weak epiphyseal plate predisposes an athlete to an avulsion fracture. Athletes often describe a pop after a forceful kick followed by sudden pain. The most common sites of pelvic avulsion injuries are the anterior inferior iliac spine and the ischial tuberosity caused by the powerful contraction of the sartorius and rectus femoris muscles, respectively. Although commonly seen in the hip, developing athletes can sustain avulsion fractures at other sites as well (see the Elbow Injuries section above). Plain radiographs of the pelvis should be carefully examined when avulsion fractures are suspected, since they can often be quite subtle radiographically.

Femoral Neck Stress Fractures

Stress fractures are relatively common among runners and military trainees, and roughly 10% of them occur in the femoral neck. Femoral neck stress fractures are often overlooked or misdiagnosed, with dire consequences. Intensive or improper training regimens and hard running surfaces place patients at risk. Patients with femoral neck stress fractures present with a deep pain in the hip, groin, or thigh that is initially present only with activity and later becomes continuous. They have pain with internal and external rotation, as well as axial loading. Because initial radiographic findings are often negative, this diagnosis requires a high index of suspicion; a bone scan or magnetic resonance imaging scan (MRI) may be necessary. Initial treatment consists of rest, non–weight bearing, and conservative management, but certain types require surgical repair. These fractures can lead to avascular necrosis of the femoral head if not properly treated.

Patellar Dislocation

Patellar dislocations occur when the quadriceps contract to extend the knee but the patella is not in the intercondylar groove and gets displaced laterally. These dislocations typically occur in sports such as dance and gymnastics that involve a lot of jumping, twisting, and pivoting. This dislocation occurs more commonly in girls. Patients present with the knee flexed in intense pain and may describe a popping sensation (Figure 25-4). The examination reveals effusion, limited range of motion, the inability to bear weight, and a laterally displaced patella. Reduction should be performed promptly. With the patient supine with the hips flexed, the knee should be gently extended while medial pressure is applied to the dislocated patella. The practitioner performing the reduction will typically feel the patella return to the tibiofemoral tract. After reduction, radiographs should be taken to rule out a concomitant fracture, and the knee should be immobilized. Patellar subluxation may be observed if the history is consistent with dislocation but the pain has improved and the examination results are normal. Patellar dislocations commonly recur, with up to 15% of pediatric patients having a second event.

Figure 25-4 Subluxation and dislocation of patella.

Osgood-Schlatter Disease

Osgood-Schlatter disease, the most common overuse injury of the adolescent knee, occurs at the anterior tibial tubercle. Athletes involved in sports that involve substantial cutting, running, and jumping are at risk, and they typically present with pain, swelling, and prominence of the tibial tubercle (Figure 25-5). On physical examination, tenderness at the tibial tubercle can be elicited. Radiographs are not necessary to make this clinical diagnosis, but when obtained, they can demonstrate soft tissue swelling over the tibial tubercle or fragmentation of the tubercle. Osgood-Schlatter disease is typically a self-limited disease and usually resolves with closure of the tibial growth plate. Treatment involves symptomatic control with nonsteroidal antiinflammatory drugs and may involve limitation of activity until improvement of the pain and limp. Stretching of the quadriceps and hamstrings as well as physical therapy to strengthen the quadriceps can be helpful.

Figure 25-5 Osgood-Schlatter lesion.

Patellofemoral Pain Syndrome

Patellofemoral pain syndrome (PFPS) is the most common cause of knee pain in the outpatient setting and is the cause of up to 25% of all injuries in runners. Affecting one or both knees, PFPS occurs most commonly in adolescents and young adults, and affects females more often than males. PFPS is multifactorial resulting from overuse or overload of the knee, abnormal tracking of the patella, and muscular causes such as imbalances between the quadriceps. Patients with PFPS often have anterior knee pain or pain behind the patella. They typically complain of pain during running, going down stairs or inclines, or with prolonged sitting, which improves with ambulation. The patient may note a recent change in activity, such as an increase in a training regimen. Physical examination may reveal a medially displaced patella, tenderness of the articular surface of the patella while the knee is extended, crepitus, or a positive patellar stress test result. This test involves the physician fixing the patella against the femur and asking the patient to contract the quadriceps. This maneuver causes pain in patients with PFPS. PFPS is a clinical diagnosis, and radiographs are unnecessary before the initiation of care. Treatment includes avoiding activities that cause pain. Exercises to increase the strength of the quadriceps and flexibility of the hip, hamstring, calf, and iliotibial band are important in the recovery phase. Adjunctive therapies include foot orthosis, bracing, and patellar taping.

Osteochondritis Dissecans

Osteochondritis dissecans is a osteochondral lesion that affects subchondral bone and overlying articular cartilage. A fragment of bone or cartilage partially or completely separates from the joint surface. This disease process occurs most commonly in teenagers and usually affects one joint, most often the knee. The cause is not completely known but is likely a combination of factors, including genetic predisposition, trauma, and interruptions in the blood supply. The usual presentation is generalized pain, which worsens with a twisting motion, and swelling. Patients may complain of stiffness, weakness, or a mechanical sensation such as a popping, locking, or clicking in the knee. Radiographs can be helpful in determining the location of the lesion, but a bone scan or MRI may be necessary. Low-grade lesions heal spontaneously with conservative treatment. If a lesion loosens, internal fixation or debridement may be required.

Soft Tissue Injuries

Medial collateral ligament or lateral collateral ligament injuries are rare when the epiphysis is open because the involved ligaments are stronger than the growth plate. When present, swelling may be minimal, but tenderness will be present over the involved ligament. The knee should be tested for laxity with varus and valgus testing, as shown in Figure 25-6. Anterior cruciate ligament injuries involve rotational forces on a fixed foot. The patient will report a “pop” and rapid swelling with decreased range of motion. The Lachman test (Figure 25-7) is a method of detecting this injury. Arthroscopy or MRI is often needed for definitive diagnosis.

Figure 25-6 Abduction stress (forced valgus) test and adduction stress (forced varus) test.

Figure 25-7 Lachman test of the knee.

Shin Splints

Shin splints are a common overuse injury of the lower leg, presenting with pain along the medial tibia. Pain starts toward the end of exercise and begins earlier and lasts beyond the cessation of exercise if continued exercise occurs. Diagnosis can be made by history and physical examination. Radiographic studies are sometimes necessary to rule out a stress fracture. Treatment involves relative rest and correcting training errors. Fitness can be maintained with alternative exercises such as swimming or cycling.

Ankle Sprains

The ankle is a hinge joint formed by the distal tibia, distal fibula, and talus. Ankle injuries are extremely common in athletes. About 85% are sprains and, of those, 85% percent are inversion injuries. However, in a preadolescent patient, growth plate injuries (Salter-Harris fractures) are more common than sprains. A detailed history about the position of the ankle at the time of injury and the direction of forces are useful in making an assessment. If no deformity is obvious, the clinician should inspect for bruising and swelling and palpate the bony structures of the ankle, including the fibula, distal tibia, and proximal fifth metatarsal. The more common inversion mechanism produces injury to the lateral portion of the foot and ankle, usually the anterior talofibular ligament. The anterior draw test helps to assess the status of the ankle ligaments. A significant difference between the affected and unaffected ankle may suggest a tear of the anterior talofibular ligament. Passive and active range of motion should also be assessed.

Radiographs of the ankle should be obtained when patients are unable to bear weight or have malleolar tenderness. Children with point tenderness who are likely to have open growth plates should have radiographs to rule out Salter-Harris fractures. Early treatmen of ankle sprains includes RICE (rest, ice, compression, elevation) and early mobilization. Functional rehabilitation should begin on the day of injury. It includes range of motion exercise, muscle strengthening, and then activity-specific training.

Sever Disease

Sever disease is an inflammation of the apophysis at the posterior aspect of the calcaneus. It is twice as common in boys and occurs bilaterally 60% of the time. The presentation is between 8 and 13 years of age. Patients complain of heel pain related to activity. Sports involving running and jumping predispose children to Sever disease. There is tenderness to palpation at the insertion of the Achilles tendon into the calcaneus, and the heel cords are tight. Treatment includes relative rest, ice, massage, stretching, and strengthening of the Achilles tendon.