OSTEOCHONDRITIS DISSECANS OF THE CAPITELLUM

JEFFREY GUTTMAN, M.D., Resident, Orthopaedic Surgery

CRAIG MORGAN, M.D., Attending, Orthopaedic Surgery

June 4, 1996

CLINICAL CASE PRESENTATION

ORTHOPAEDIC DEPARTMENT

THE ALFRED I. DUPONT INSTITUTE

WILMINGTON, DELAWARE

CASE HISTORY:

This Patient is a 14 year old right hand dominant male who complains of right elbow pain, swelling, and decreased ROM which has occurred intermittently over the past year. He also describes clicking and "catching" of the elbow. He claims that the pain has been getting progressively worse and that it is worst after throwing when he plays dodgeball. On physical examination, the patient has a minimal joint effusion and is tender over his radiocapitellar joint line. He also lacks 15 degrees of terminal elbow extension, but has full flexion. There is some crepitus with ROM. Plain X-rays of the elbow show focal islands of subchondral bone adjacent to the articular surface of the capitellum demarcated by a rarefied area. The patient was scheduled for an elbow arthroscopy and possible drilling of the lesion vs. debridement and removal of loose bodies. During the arthroscopy the lesion was noted to be almost completely detached. It was debrided and excised. No drilling was performed.

INTRODUCTION:

• Focal lesion of capitellum
• One of numerous entities under term "Little League elbow"

(medial epicondyle avulsion, delayed or accelerated growth medial epicondyle, medial epicondyle apophysitis, delayed closure med. epicondyle growth plate, osteochondrosis or OCD capitellum, deformity of radial head, olecranon apophysitis)

• Throwing athletes - baseball pitcher, tennis (serve), football (pass), javelin thrower, gymnast
• Not as common as medial elbow injury
• One of leading causes of permanent elbow disability in young throwing athletes

HISTORY:

• Panner (1927) - first described lesion in capitellum similar to Perthes disease of hip

(different etiology, onset, prognosis than OCD)

• Brogdon & Crow (1960) - "Little League elbow;" described assoc. b/w pitching and medial epicondylar injuries
• Adams (1965) - lateral elbow joint damage secondary to pitching (6 cases of OCD of capitellum)

CAUSES:

• Trauma/excessive use - well documented secondary to repetitive stress to elbow of pitching; almost always dominant elbow
• Vascular anatomy - may make capitellum more vulnerable to trauma
• Genetic factors - high incidence of bilateral disease; common occurrence among relatives of affected patients

BIOMECHANICS:

• Elbow stabilizers :
• medial - MCL
• lateral - bony articulation of radial head/capitellum
• posterior - olecranon/olecranon fossa articulation
• These structures resist valgus forces of throwing and can be injured
• Valgus stress is the major pathologic mechanism of elbow (causes medial tension and lateral compression)
• Compression overload of lateral articular surface - radial head abuts capitellum
• occurs mainly during early and late cocking phases
• also during follow through with rapid, maximal pronation

HISTORY AND PHYSICAL:

• Age 13 - 16. Usually male.
• Throwing athlete
• Insidious onset elbow pain; worse after throwing
• Dominant arm
• Decreased ROM (particularly extension)
• Crepitus, grinding
• Later c/o locking, catching with severe pain

RADIOGRAPHIC FINDINGS:

• Plain XRays
• focal island of subchondral bone adjacent to articular surface of capitellum demarcated by rarefied zone
• radiolucent, cystic-like area
• irregular ossification of capitellum
• radial head changes (irregularity, hypertrophy)
• loose bodies
• Initial XRay may be negative
• Tomogram may help determine whether articular surface and subchondral bone are dissected from capitellum

CLASSIFICATION:

• Type I : Intact lesion; no evidence of fracture of articular surface
• Type II : Partial detachment of lesion
• Type III : Completely detached loose body

TREATMENT:

Conservative

• For Type I lesions can try rest, NSAIDs, avoiding all throwing activities
• If severe pain, splint 3-4 wks. Then begin active ROM
• Protect elbow until see radiographic evidence of revascularization and healing

Surgical

• Indications : if conservative treatment fails to relieve pain or gain elbow extension; locked elbow; more aggressive approach: any painful OCD (including Type 1)
• Arthrotomy/arthroscopy
• Drilling
• Debridement
• Removal loose bodies
• Internal fixation loose fragments, bone grafting poor results

Prognosis

• Often marks end of hard painless throwing
• Usually cannot return to pitching
• Promising results with arthroscopy/drilling Type I lesions
• Symptoms improvement with debridement, removal loose bodies

REFERENCES:

I . Andrews, J. Bony Injuries about the Elbow in Young Throwing Athletes. Instr. Course Lect. 34: 323-331, 1985.

2. Bauer, M., et al. Osteochondritis Dissecans of the Elbow. CORR 284: 156-160, 1992.

3. Brown, R., et al. Osteochondritis of the Capitellum. J of Sports Med, Vol. 2, No. 1: 27-46, 1974.

4. Jackson, D., et al. Osteochondritis in the Female Gymnasts Elbow. Arthroscopy 5(2): 129-136, 1989.

5 . McManama, G., et al. The Surgical Treatment of Osteochondritis of the Capitellum. Am J Sports Med 13(l): 11-21, 1985.

6. Pappas, A. Elbow Problems Associated with Baseball during Childhood and Adolescence. CORR 164:30-41, 1982.

7. Smith, M. Osteochondritis of the Humeral Capitellum. JBJS 46B, No. 1: 50-54, 1964.

8. Waugh, T., et al. Surgical Management of Osteochondritis Dissecans of the Capitellum. Am J Sports Med 4(3): 121-128, 1976.