Frequency, imaging findings, risk factors, and long-term sequelae of distal clavicular osteolysis in young patients.

OBJECTIVE: Atraumatic distal clavicular osteolysis (DCO) has been described in adult male weightlifters. Our purpose was to investigate the frequency, magnetic resonance imaging (MRI) characteristics, risk factors, and long-term sequelae of DCO in young patients.

MATERIALS AND METHODS: Individuals with atraumatic DCO were identified in a retrospective review of 1,432 consecutive MRI shoulder reports in patients between 13 and 19 years of age. MRI findings of DCO, association with athletic activity, short-term clinical outcome after 3-6 months, and long-term clinical and MRI outcome after 2 years were analyzed. A pre-MRI questionnaire assessed the patients' athletic history including overhead activity and weightlifting.

RESULTS: At a mean age of 15.9 years, 6.5 % (93/1432) of patients had atraumatic DCO, and 24 % were females. The combination of an overhead sport (basketball, volleyball, tennis, swimming) and supplemental weight training was a risk factor for DCO (odds ratio = 38, p = 0.01). Ninety-three percent of patients responded to conservative therapy. On follow-up imaging, 71 % of DCO patients had acromioclavicular (AC) joint osteoarthritis (vs. 35 % in controls, p = 0.006); 79 % had flattening of the distal clavicle and interval widening of the AC joint to a mean of 5.0 mm (compared to 2.4 mm in controls, p < 0.001). Severity of DCO edema was associated with pain (p < 0.02) at initial presentation and with AC joint osteoarthritis (p = 0.004) on follow-up.

CONCLUSION: In athletic teenagers, the combination of weightlifting and overhead activity is a risk factor for atraumatic DCO, and females are affected in 24 %. Long-term sequelae include widening of the AC joint and AC joint osteoarthritis.