A BIOMECHANICAL COMPARISON OF LATERAL RETINACULAR RELEASES

A lateral patellar retinacular release that transects the tendon of th e vastus lateralis muscle may result in significant complications. To avoid such complications, the superior extent must be limited, and max imizing the inferior extent may be important in achieving an adequate release. The effective release of the patella from its lateral retinac ulum was examined for 2 incision lengths using 10 fresh-frozen human c adaveric knees and comparing the medial displacement of the patella re lative to the femur for 3 study groups (control, intact retinacula; Gr oup A, retinacula cut from the inferior third of the vastus lateralis tendon down to the anterolateral arthroscopic portal; and Group B, ret inacula cut from the inferior third of the vastus lateralis tendon dow n to the tibial tubercle) when a 22-N medially directed force was appl ied to the patella with the knee at 30 degrees and 60 degrees of flexi on. The extended release (Group B) resulted in a significantly more ef fective release when compared with the standard release (Group A) or c ontrol group. This technique may allow an adequate release of the pate lla while preserving the function of the vastus lateralis muscle.