Hip Joint Cartilage Defects in Professional Ballet Dancers: A 5-year Longitudinal Study.

ABSTRACT

OBJECTIVE: A causal link between ballet, hip pain, and pathology has not been established. Change in ballet dancers' hip pain and cartilage defect scores were investigated over 5 years. DESIGN: Longitudinal. SETTING: Professional ballet company. PARTICIPANTS: Twenty-one professional ballet dancers (52% men). INDEPENDENT VARIABLES Baseline and follow-up Copenhagen Hip and Groin Outcome Score (HAGOS-pain subscale); incidence of hip-related pain and levels of dance participation collected daily over 5 years; bony morphology measured on baseline 3T magnetic resonance imaging (MRI). MAIN OUTCOME MEASURE: Change in cartilage defect score on MRI between baseline and 5-year follow-up. RESULTS: Cartilage scores did not increase in 19 (90%) dancers. There was one new cartilage defect and one progressed in severity. At follow-up, all 6 dancers with cartilage defects were men. Group HAGOS pain scores were high 97.5 (7.5) and not related to cartilage defects (P = 0.12). Five (83%) dancers with baseline cartilage defects reported HAGOS pain scores <100 at follow-up. There were no time-loss hip injuries over 5 years. Two (33%) dancers with cartilage defects recorded hip-related pain (one reported minor training modification). Femoral neck-shaft angles (NSAs) were lower in men with cartilage defects [129.3 degrees (3.4 degrees)] compared with those without cartilage defects [138.4 degrees (4.5 degrees); P = 0.004]. CONCLUSIONS: Elite level ballet did not negatively affect cartilage health over 5 years. Cartilage defects were related to low femoral NSAs. Most cartilage defects did not progress and there was minimal impact on dance participation and pain levels. Longer follow-up is required to determine the long-term sequelae for those with cartilage defects. LEVEL OF EVIDENCE 1b.