Podium (Sports) 06

Outcome evaluation of medial patello-femoral ligament reconstruction in recurrent patellar dislocation using double tunnel technique

Vishnu Senthil, MD
Senior Resident, GRH, Chennai, India

Introduction: Recurrent patellar instability is a common problem after initial dislocation due to non-healing of the medial patellofemoral ligament (MPFL). MPFL reconstruction lead to improved clinical outcome. MPFL reconstruction aims at graft attachment over the Schottle’s point of medial femoral condyle. Malposition of Femoral tunnel may affect the clinical and radiological outcome after MPFL reconstruction.

Materials and Methods: Retro-prospective study involving 21 patients with a minimum followup of 2 years. Clinical evaluation included preoperative and postoperative apprehension test, maltracking and patellar tilt along with Kujala and Lysholm score. MPFL reconstruction was done by transverse tunnels in patella and anatomic placement of femoral tunnels using Semitendinosus graft. The femoral tunnel position was decided by manual palpation of adductor tubercle and medial epicondyle without fluoroscopy guidance. Graft was fixed in femoral tunnel by interference screw. Post-operatively, position of femoral tunnel (Schottle’s point) was assessed using a CT scan and was correlated with clinical outcome.

Results: Mean follow up was 35.2 months (range 24-47 months). None of the patients had dislocation after surgery. All the patients with preoperative positive apprehension, maltracking and lateral patella tilt turned negative at final follow up. Mean preoperative kujala and lysholm score were 53.16 and 58.79, post-operative score was 92.16 and 94.53 respectively with a P value "0" for both which is statistically significant .The center of the femoral tunnel was found to be placed at the Schottle’s point in 47.3% (n=9) of the cases and in the rest anterior or posterior to the Schottle’s point. The distance of femoral tunnel from Schottle’s point was found to be within the mean radius of 8.32 +/- 2.3 mm calculated using the methos proposed by schottle et al .There were none superior inferior placements with respect to Schottle’s point when assessed using squares method proposed by servien et al. There were no difference in clinical scores of patients who had femoral tunnel at Schottle’s point or away.

Conclusion: MPFL reconstruction improves the functional outcome in patients with patellar dislocation. The anteroposterior deviation of femoral tunnel from the Schottle’s point does not have any effect over the clinical outcome. Manual palpation of anatomic landmarks is an effective method for deciding the position of femoral tunnel which will reduce the use of fluoroscopy and subsequently radiation exposure.