Surgical treatment of recurrent habitual patellar dislocation associated with severe trochlear hypoplasia and generalized ligament laxity

Introduction: Recurrent habitual patellar dislocation can be treated by soft tissue reconstruction or osteotomy or combination of both. However, no single surgical procedure can address the complex issue. We have successfully treated three patients (four knees) with trochlea hypoplasia and generalized ligament laxity with different surgical techniques. Patients and Methods: From January 2001 to November 2008, four knees of three female patients were presented with recurrent habitual dislocation of the patella and generalized ligament laxity. Different surgical procedures were performed, including Insall proximal realignment in two knees, Roux-Goldthwait procedure in one knee, and combined trochleoplasty and tibial tubercle transfer in one knee. This article reports the functional and radiographic assessments at a mean follow-up of 3.4 years. Results: The modified Cincinnati score increased from 74 ± 9 preoperatively to 88 ± 6 at latest follow-up; and the Kujala patellofemoral disorder score increased from 75 ± 10 to 86 ± 11. No recurrent dislocation occurred on all knees. Radiographic parameters improved, including congruence angle and axial linear patellar displacement. The sulcus angle improved in patient who underwent combined trochleoplasty and tibial tubercle transfer. Conclusions: Surgical treatment for recurrent habitual dislocation of the patella varied according to the severity of the anatomical abnormality and the patellar stability assessed intraoperatively. In severe cases, combined trochleoplasty and tibia tubercle transfer is indicated to correct the recurrent dislocation of the patella. Proper patient selection and good surgical technique are the keys to success.