Tibial tuberosity osteotomy and medial patellofemoral ligament reconstruction for patella dislocation following total knee arthroplasty: A double fixation technique

Abstract

Introduction: Patella instability post total knee arthroplasty (TKA) is a rare complication. Tibial tubercle osteotomy (TTO) with medial patellofemoral ligament reconstruction (MPFLr) has not been well described for this indication. This paper describes a surgical technique to address the unique challenges faced when performing TTO and MPFLr in the prosthetic knee. Technique: This technique and video describe a TTO and MPFLr via an extensile incision and medial sub-vastus approach. A 6 cm long TTO is performed, if indicated, to medialise the extensor mechanism up to 1 cm and fixed with ×2 4.5 mm cortical screws. For the MPFLr, a quadriceps tendon autograft is utilized, with the natural insertion to the superior pole of the patella being left undisturbed. The graft is first attached with an interference screw and then reinforced with an endobutton to provide crucial cortical fixation to overcome the problem of low bone mineral density encountered in this area of the femur following TKA. Results: Five patients underwent MPFLr using the described technique. No failures or recurrence of instability occurred at the last follow-up. Pre-operative mean patella tilt and shift were 44° and 3.5 cm, respectively. Post-operatively, mean tilt and shift were 4.1° and 0.4 cm, respectively. There was one wound dehiscence requiring surgical debridement and closure. Conclusion: This paper describes a surgical technique to perform a TTO and MPFLr for patella instability post-TKA. The described method highlights key adaptations to address the unique challenges in this patient population.

What is the best fixation method in medial patellofemoral ligament reconstruction? A biomechanical comparison of common methods for femoral graft attachment

“…Multiple methods exist for bony attachment of the graft to the patellar and femoral sites in MPFLr as screw fixation, endobutton, suture anchors [5,6,[10][11][12][13][14] and soft tissue fixation [15]. Several studies have examined the biomechanical performance of fixation devices for the patella [5,10,11,[16][17][18][19], less for the femur [20,21] and in some studies, it has been simultaneously tested (femur and patella) limiting interpretation of individual fixation methods [22][23][24][25].…”

Surgical techniques for medial Patellofemoral ligament reconstruction: a systematic review and meta‐analysis of level I and II studies

“…Interference screw fixation involves using a biocompatible screw to compress the graft against the bone [7]. Endobutton fixation involves looping the graft with an endobutton device, and suture anchor fixation involves using sutures to tie the graft through holes in the bone [7, 32]. Despite various individual studies on graft options, tunnel techniques, and fixation strategies, there is no comprehensive source outlining the optimal strategies for each aspect of MPFLR.…”