Synovial Chondromatosis: A Rare Differential Diagnosis of Hip Pain in a Child.

INTRODUCTION: Primary synovial chondromatosis (SC) is a disease of the synovium occurring in the third to fifth decade of life with the peak incidence in the fifth decade and commonly involves the knee in 50% cases. The diagnosis of SC is primarily radiological and intraoperative. Primary SC of the hip is rare, and their prevalence is not known.

CASE REPORT: A 7-year-old female child presented with pain and limp left hip for 6 weeks. She had a stiff hip gait. Clinical examination revealed a fixed abduction, flexion deformity, and restricted internal rotation with apparent lengthening of 2 cm. The ultrasonography revealed synovial effusion with synovial deposits. Magnetic resonance imaging revealed features of tuberculous synovitis, inflammatory synovitis, or a rare possibility of SC. Arthrotomy was performed following failed hip aspiration. Multiple chondral loose bodies were noted on incision of capsule. Partial synovectomy was also performed. The synovium histopathology revealed multiple synovial chondral inclusions. A final diagnosis of SC was made.

CONCLUSION: We report this case of primary SC, 7-year-old female patient with symptoms of hip pain, limp, and fixed deformities restricting hip function as a first of its kind in the mentioned age group. Hence, although rare SC may be considered as one of the differential diagnosis in hip symptoms in children <10 years of age.