Tibial tubercle proximalization as quadriceps lengthening in treating severe habitual patellar dislocation in adults.

Abstract

To describe a novel 'four-in-one' procedure - including tibial tubercle proximalization, extensive lateral release, tibial tubercle medialization, and medial patellofemoral ligament reconstruction - for treating severe habitual patellar dislocation (HPD) in adults, and to report its early clinical outcomes. Thirteen patients (13 knees) with severe primary HPD received this procedure. Results of the physical examinations, including apprehension tests and patellar tracking throughout full range of motion, were recorded pre-operatively and at final follow-up. Radiological assessments included standard anteroposterior view, true lateral view at 30° knee flexion, axial views of the patellofemoral joint at both 30° and maximum angle of knee flexion, and computed tomography scans at full knee extension pre-operatively and at final follow-up. Subjective patellofemoral functions were evaluated with the Kujala functional score before the index procedure and at final follow-up visit. All 13 patients were followed for an average period of 35.5 months (range, 25-49). After the index 'four-in-one' procedure no patient reported reoccurrence of patellar dislocation at the final follow-up visit. Radiographically, there was a statistically significant improvement in the congruence angle from 75.2 ± 16.3° pre-operatively to -7.2 ± 5.4° postoperatively (P < 0.01) and in the lateral patellofemoral angle from -66.3 ± 8.3° pre-operatively to 6.3 ± 2.6° postoperatively (P < 0.01). The average pre-operative Kujala functional score was 41.4 and average postoperative score was 94.9 (P < 0.05). The novel 'four-in-one' procedure effectively treated HPD in adults with severe quadriceps contracture.