Michael J. Medvecky, MD, FAAOS

The study by Sochacki and colleagues provided a systematic review of the existing literature on the anatomic analysis of the origin of the MPFL in relation to the distal femoral physis. The implications of physeal arrest if performing an anatomical MPFL reconstruction has previously led toward non-anatomical reconstructions. The proximity of the adductor tendon and its attachment site at the adductor tubercle has been utilized for fixation of grafts in the skeletally immature but may have altered biomechanical forces due to its proximal and posterior position in relation to the MPFL origin.

This review identified that the MPFL attachment site is in 93% of specimens an average of 7 mm distal to the distal femoral physis. An additional surgical pearl highlighted in this review was the fact that the distal femoral physis becomes distal to the MPFL origin at a point 10.5 mm lateral to the MPFL attachment site on the medial femur. A direct lateral drilling has the potential for disrupting this physis. They advocate directing the drill distal and anterior in relation to the coronal plane to avoid injury to the distal femoral physis. The benefit of intraoperative fluoroscopy to verify tunnel positioning is highlighted.

The systematic review gives support to the ability to provide anatomic MPFL reconstruction in the skeletally immature patient. The benefit of an anatomic reconstruction is the potential for a more normal or improved biomechanical environment, enhanced stability and improved tolerance of return to previous activity level. The technical considerations are of high importance to lessen injury to the distal femoral physis that may not been seen from an external, extracortical perspective.