Isolated medial patellofemoral ligament reconstruction for recurrent patellar dislocation.

Background: Several medial patellofemoral ligament reconstruction procedures have been proposed to manage recurrent patellar dislocation. Hypothesis: Reconstruction of the medial patellofemoral ligament using a hamstring graft with a 2 transverse patellar tunnels technique is an effective treatment for recurrent patellar dislocation in patients without any evident predisposing factors. Study Design: Case series; Level of evidence, 4. Methods: Twenty-eight patients with chronic patellar instability without any anatomic predisposing factors, experiencing recurrent unilateral patellar dislocation, were included in the study. Evaluation included the modified Cincinnati and the Kujala scores, anthropometry, plain radiography, and isokinetic dynamometry. Results: The average follow-up was 3.1 years (range, 2.5-4 years). The mean modified Cincinnati score increased from 52 preoperatively to 89 (P = .001). The mean Kujala scores increased from 45 preoperatively to 83 (P = .03). The muscle volume of the thigh of the operated limb increased with time, but remained less well developed than the nonoperated limb (P = .04). The mean Insall-Salvati index was 1.1 (range, 0.9-1.2) preoperatively and remained within normal range (1.1 [range, 0.9 to 1.2]) (P = .07), at latest follow-up. Significant isokinetic strength differences were found between the operated and the contralateral limbs (.05 < P < .006), even at the latest follow-up. Three patients experienced a new patellar dislocation. Conclusion: Medial patellofemoral ligament reconstruction using hamstring tendon passed through a double patellar transverse bony tunnel technique is a safe, reliable management option for recurrent patellar dislocation in patients without any predisposing anatomic factors.