Evaluation and Treatment of the Medial Patellofemoral Ligament (MPFL)
Evaluation and Treatment of the Medial Patellofemoral Ligament (MPFL) Basic Facts: 2-3% of all knee injuries 15-44% recurrence; 49% in those that have previously dislocated twice. ~ 16% re-dislocation in those treated non-op; ~ 33% have residual Sx; remaining 50% will be asymptomatic. Anatomy: Origin: superior medial aspect of the patella Insertion: space b/n adductor tubercle and medial epicondyle Some fibers blend with VMO Function: As knee flexes, VMO and MPFL pull patella medially to help it remain in trochlea Provides stability against lateral translation Biomechanics: Provides 50-60% restraint to lateral patellar translation at 0-30 degrees flexion If sectioned, patella displaces laterally even w/ all other medial stabilizers intact Loses tension as the knee is flexed, tightest b/n 25-30 degrees of knee flexion and creates a medial shift; this shift is not appreciated in knees w/ resected MPFL. Patella enters the trochlea around 15-20 degrees of knee...