Complications and failure of MPFL reconstruction with free tendon grafts in cases of patellofemoral instability.

BACKGROUND: Reconstruction of the medial patellofemoral ligament (MPFL) using free tendon grafts has become a widespread treatment option for patellofemoral instability. As the numbers of cases gradually grow, so do the reports of possible peri- and postoperative complications following this procedure. OBJECTIVE: The present review summarizes all known complications of MPFL reconstruction with regard to postoperative outcome and seeks to highlight possible pitfalls that may occur during treatment. CONCLUSIONS: MPFL reconstruction generally has to be regarded as a safe procedure today due to low patellar re-dislocation rates. Complication rates however are not trivial owing to the complexity of the underlying pathology. Complications can arise from graft fixation or femoral tunnel placement. Postoperative flexion deficits and medial knee pain have been described as predominant complaints. Anatomical preconditions as the grade of trochlear dysplasia, axis or torsion of the lower extremity have to be considered in search of causes for possible graft failure as well as in the thorough preoperative planning of the procedure.