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An ice hockey player with an unusual elbow injury

Rob Powers, PA-C, ATC

Rob Powers is a PA in orthopedic surgery at Mattern & Associates, Dover, Delaware. He has indicated no relationships to disclose relating to the content of this article.

CASE

A 16-year-old right-hand-dominant male presented to the clinic with a complaint of left elbow pain. The patient, who played goalkeeper for his hockey team, stated that while tending goal, he caught the puck in his gloved left hand with his elbow flexed and his arm abducted. He denied striking his elbow on the far goal post. He denied any falls or contact that would have led to an elbow injury. He also denied any history of previous injury or pain associated with his left elbow. He complained of pain on the outer aspect of his elbow but denied any mechanical symptoms, locking, clicking, or catching with elbow movement. He had intermittent swelling of the affected elbow. He had continued playing hockey since the onset of elbow pain with only mild limitation secondary to the pain.

Physical examination demonstrated normal range of motion of the elbow without joint effusion. The ligaments were intact, with pain and point tenderness along the radiohumeral joint. Specifically, there was tenderness on the capitellum. No palpable loose bodies were noted. Radiographs of the elbow were obtained (see Figure 1). What does the radiograph show?

DISCUSSION

Figure 1 is an anteroposterior view of the elbow demonstrating osteochondritis dissecans (OCD) of the capitellum. The radial head appears normal, without flattening or evidence of articular surface derangement; however, evidence of sclerosis is visible along the posterior rim of the radial head, which suggests chronic repetitive valgus movements to the elbow. The capitellum demonstrates deformity with a white sclerotic border surrounding a visible defect that appears dark as compared to the surrounding cortical bone. The image provides radiographic evidence of a bony abnormality of the capitellum, suggesting OCD.

Osteochondritis dissecans typically affects 13- to 16-year-old adolescents. Panner’s disease is similar to OCD, but it is usually characterized as osteochondrosis and affects youngsters 7 to 12 years old. OCD of the elbow most often occurs in overhead-throwing athletes and in gymnasts. In this case, unusually, the affected joint is on the nondominant extremity that is not involved with throwing.

Although this patient’s injury initially appeared to have been caused by a traumatic event, MRI studies obtained after the initial radiographs disproved this theory. Figure 2 is a sagittal T1 image demonstrating a 1.3-cm osteochondral defect of the capitellum that appeared chronic, along with a 1-cm loose body in the posterolateral recess of the elbow that was not evident on plain films. These findings suggest a chronic injury, as is typical for OCD, even though the actual event that caused this patient to seek care was his injury while playing hockey. The hockey event may have dislodged the osteochondral fragment, causing elbow pain and swelling, because before this event the patient was free of pain.

OCD of the elbow typically results from constant, high-energy repetitive motions usually involved with throwing. The vascular supply to the capitellum is limited to one or two isolated vessels, which compromises the ability of the capitellum to heal itself after injury. The toggle effect the elbow goes through when a person throws is what causes the injury. During the cocking phase of throwing, the elbow is in a valgus stressed position with the radial head abutting the capitellum, forming a toggle or a solid back stop that helps deliver power and leverage to a throw while producing shear and compression forces on the capitellum. Going through this motion repeatedly decreases the ability of the articular cartilage of the capitellum to resist stress and ultimately produces injury. This same diminished capability to resist stress in turn prevents the articular cartilage from healing, leading to fragmentation of the articular surface of the capitellum and subsequent OCD. In unusual cases, a single isolated traumatic event can also produce OCD, as was initially assumed to be true for this patient.

Diagnosis of OCD starts with the history. What makes this case unusual is that the affected joint is on the nondominant extremity that is not involved with throwing. The patient had no pain before catching the hockey puck, but typically athletes will describe mild pain, swelling, and/or mechanical symptoms that lead the clinician to suspect some form of joint involvement. This patient denied any of these symptoms.

After plain films were obtained, the diagnosis of OCD involving the capitellum was clear. MRI was ordered to gauge the age, depth, and severity of the injury as well as to determine if any concomitant pathology was present. This MRI is how the loose body was found.

Treatment for OCD depends on the age of the patient. A skeletally immature athlete typically is restricted from overhead activities and is prescribed rest and ice. Skeletally mature athletes are usually treated surgically, which involves removal of any loose bodies in the joint. Surgery for the OCD itself depends on the severity of the injury and might include arthroscopic debridement/chondroplasty, drilling, microfracture, or in some cases an osteochondral autograft transfer system (OATS) procedure. Reattachment of the loose body itself is not advocated as it has an extremely poor success rate.

Debridement/chrondroplasty involves shaving the articular surface of the capitellum to smooth out the cartilage and typically produces a good result for small lesions. Larger lesions are treated either with the microfracture technique, which stimulates fibrocartilage to grow and fill in the defect, or with drilling of the defect, which also can stimulate healing. The OATS procedure involves utilizing an autogenous graft of bone and cartilage to replace the damaged articular surface of the capitellum. The trochlea of the knee is a good harvest site for this procedure.

Long-term outcome depends on whether the injury is recognized and treated appropriately and on the age of the patient. MRI was crucial in this instance as it revealed a loose body that was clearly not evident on radiographs. This finding meant that the patient required a procedure to remove the loose body and underscores the value of MRI in these cases. If surgery is not initially planned, as it might not be for a young person, MRI is crucial to confirm that surgery is in fact not needed to prevent possible future joint derangement from an undiscovered loose body. In some patients with severe injury, future athletic activity is prohibited. In this case, the patient was a nonthrower and aspired to play collegiate hockey. Surgical treatment was recommended because it would provide him with the best opportunity for a future in athletics. JAAPA

Julie Vajnar, PA-C, RT, department editor