Treatment of patellar instability in a case of hereditary onycho-osteodysplasia (nail-patella syndrome) with medial patellofemoral ligament reconstruction: A case report

Hereditary onycho-osteodysplasia, also known as nail-patella syndrome (NPS), is a rare genetic disorder that is primarily characterized by poorly developed nails and patella. Patients with NPS frequently suffer from patellar instability that requires surgical management. The present case report describes a 25-year-old man with NPS. The patient presented with left knee pain and was found to have recurrent left patellar dislocation. The knee pain was first reported 1-year after a minor knee trauma incident. Following complete evaluation, a diagnosis of NPS was reached. The patient underwent surgical intervention using medial patellofemoral ligament (MPFL) reconstruction with a gracilis tendon autograft looped through two transverse 3.2-mm drill holes in the patella and fixed at the natural MPFL insertion site on the medial femoral condyle with an interference screw. The surgery resulted in stabilization of the patella in the femoral trochlea and the patient did not have any subsequent dislocations or subluxations. The patient had an excellent range of knee movement in the follow-up period. This case indicates that MPFL reconstruction in patients with patellar dislocation secondary to NPS can successfully restore normal patellar tracking and result in good range of movement and functional activity.