Clinical outcome of Patella stability after fixation of Osteochondral fracture in Acute Primary Traumatic Patella Dislocation without MPFL Repair or Reconstruction

Abstract

Introduction: Conservative management is advisable for acute primary traumatic patella dislocation (PTPD). Surgical treatment is reserved for osteochondral fractures (OCF), medial patello femoral ligament (MPFL) avulsion/tear, compound injuries, and any underlying bony abnormalities requiring correction. MPFL repair (at avulsed site) or reconstruction along with underlying bony correction in PTPD is controversial. The purpose of this study is to evaluate patella stability after fixation of OCF in PTPD without performing MPFL repair or reconstruction, even in the presence of any underlying bony abnormalities. Material and Methods: This is a retrospective study of eight patients who had PTPD with OCF along with MPFL injury who presented between 2016 and 2019. Pre-operative X-rays and MRI were done to assess the status of MPFL, identify the presence of OCF and to calculate Insall-Salvati index, Tibial Tuberosity-Trochlear groove distance and Trochlear dysplasia. All patients underwent surgery by open approach and OCF fixation by bioabsorbable pins or suture material. MPFL was neither repaired at avulsed site nor reconstructed and even no bony corrections were done. Results: Average size of OCF fragments is 15*7 mm and all involving medial facet of patella. Lysholm score improved significantly from 32.8 to 94.8 and Kujala score from 49.1 to 96 at the end of 6 months. None of the patient had patella instability till latest follow-up, average follow-up period is 4.5 years (3–6 years). Clinically, apprehension test was negative in all cases with full ROM. Post-operative imaging including X-ray and MRI showed complete healing of the OCF along with complete healing/regeneration of MPFL with same pre-existing bony abnormalities if present preoperatively. Conclusion: This study shows excellent patella stability and full knee function along with complete union of OCF and complete healing/regeneration of MPFL in PTPD even in the presence of underlying bony abnormality. Hence, in PTPD with OCF, there is no need to repair/reconstruct MPFL or to correct underlying bony pathology, only OCF fixation is required.