Clinical and radiological outcomes following isolated double-bundle medial patellofemoral ligament reconstruction for patellar instability in mature and normal lower limb alignment patients: a 12-year follow-up case series.

Abstract

The Double Bundle Medial Patellofemoral Ligament (MPFL) Reconstruction is a reliable technique for patellar instability. Clinical studies have shown its effectiveness and reliability in minimum 5-year follow-up, however, its efficacy when it comes to more than 10 years after surgery are still unclear. This retrospective study aimed to assess the effectiveness at least 12 years postoperatively. A total of 68 patients with chronic patellar instability who underwent surgery from May 2005 to February 2010 were included prospectively. Tegner Activity Scale (TAS), Kujala score, Lysholm knee score, objective physical examination and radiological outcomes including Sulcus Angle (SA), Congruence Angle (CA), Patellar Tilt Angle (PTA) and Osteoarthritis Computed Tomography-Score (OACT-score) were assessed preoperatively, 6 years and 12 years postoperatively and survival rate was calculated at the last follow-up. Median follow-up time for the patients was 169.02 ± 14.11 months. At the last follow-up, 54 patients were enrolled in the end and underwent face-to-face follow-ups with mean TAS value of 7.35 ± 0.86, Kujala score of 93.81 ± 2.76 and Lysholm score of 92.06 ± 3.89. Radiological outcomes showed no abnormalities and were all under pathological threshold with mean SA value of 136.86 ± 3.67, CA value of -6.37 ± 2.76 and PTA value of 4.15 ± 3.03. Four patients showed OACT-score of 2 at the last follow-up. The 12-year survival rate was 96.3%. This retrospective minimum 12-year analysis showed satisfactory results in long-term follow-up of double bundle MPFL reconstruction and further confirmed it as an ideal technique to manage patellar instability.