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

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. 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. 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. 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.