Isolated MPFL reconstruction for recurrent lateral patellar instability in patients with TT-TG distance <25 mm: A calculated safe risk!

Abstract

Objectives: The objectives of the study were to describe the surgical technique of our modification of isolated medial patellofemoral ligament (MPFL) reconstruction, in patients with patellar instability. As per literature, isolated MPFL reconstruction is advocated if tibial tubercle-trochlear groove (TTTG) <20 mm. Our study proposes isolated MPFL reconstruction in patients with TT-TG <25 mm and aims to determine any predisposing anatomic variants to aid in the treatment algorithm. Materials and Methods: A retrospective analysis of 52 patients with patellar instability (TT-TG <25 mm), who underwent isolated MPFL reconstruction was undertaken. The study population was divided into two groups; TT-TG <20 mm and TT-TG = 20–24 mm. Both groups were assessed radiologically and on the basis of clinical and functional outcome (KUJALA score), over 5-year follow-up period. Results: The mean age of the study population was 21.98 years, with a female (63.5%) majority. Among the 52 patients included in the study, 39 patients (75%) had TT-TG <20 mm and 13 patients (25%) had TT-TG = 20–24 mm. We noticed statistically significant improvement in both groups with respect to clinical and functional outcome, with no reported complications. None of the patients had patella alta or high grades of trochlear dysplasia. Conclusion: MPFL reconstruction without concomitant bony procedures can be safely performed in patients with a TT-TG <25 mm, in the absence of patella alta or high-grade trochlear dysplasia. Our modification of isolated MPFL reconstruction has shown excellent long-term results. In addition, our technique uses only a single interference screw, thereby reducing cost of surgery and implant hardware.