Medial Patellofemoral Ligament Reconstruction During Primary Total Knee Arthroplasty in Patients With Pre-existing Patellar Instability: Surgical Technique.

The medial patellofemoral ligament (MPFL) is vital for patellar stability and tracking within the trochlear groove in early flexion. Although MPFL reconstruction is a well-established treatment for patellar instability in native knees, its role during primary total knee arthroplasty (TKA) remains incompletely defined. This manuscript describes a technique for concurrent MPFL reconstruction during primary TKA in select group of patients with a documented history of chronic patellar instability and persistent intraoperative maltracking despite appropriate component positioning and soft tissue balancing. Key surgical steps include individualized patellar fixation based on bone stock and resurfacing status, isometric femoral tunnel placement, graft tensioning, and selective lateral retinacular lengthening. The described technique provides a reproducible option for addressing persistent patellar instability during primary TKA in highly selected patients with longstanding instability and appropriate implant positioning. Given the risks of arthrofibrosis and the limited available evidence, the procedure should be reserved for very select cases.