Hip arthroscopic Surgery after a Diagnosis of Premature Osteoarthritis of the Hip in Three Unicyclists: A Case Series

INTRODUCTION: Although an association between femoroacetabular impingement (FAI) and sports has been reported, there are no reports regarding arthroscopic findings of osteoarthritis due to FAI in adolescent unicyclists. CASE REPORT: We present three cases of experienced unicyclists with coxarthrosis at puberty (three girls aged 17, 15, and 12 years). All three girls had bone morphology characteristics of FAI (two unicyclists with cam-type FAI and one with mixed-type FAI). None of them had a history of trauma or abnormal blood test result. The patients underwent hip arthroscopic surgery and intra-articular evaluation/treatment (acetabular labral repair, synovectomy, bone marrow stimulation [microfracture], and capsular closure). Arthroscopic findings included severe and extensive cartilage and acetabular labrum damages. After surgery, only two patients were able to return to competition. The characteristics of the unicycle competition may have led to puberty coxarthrosis due to FAI. CONCLUSION: Hip joint symptoms in adolescent unicyclists have a risk for causing severe and extensive damages to the labrum and articular cartilages at an early stage, thereby requiring preventive and attention-seeking measures.