Lateral Facet Syndrome of the Patella

Abstract

Thirty-eight knees in 34 patients with an average age of 22 years were diagnosed as having lateral facet syndrome (LFS), a painful compressive arthropathy of the lateral facet of the patella. This diagnosis was based on the physical findings of tenderness at the lateral patellofemoral joint line, tenderness over the vastus lateralis obliquus (VLO) tendon just above the patella, a positive medial apprehension test, and marked resistance to medial patellar displacement with the knee flexed 30 degrees. The most common complaints were patellar pain with activity, pain with prolonged knee flexion, intermittent knee swelling, and giving way. At surgery, the VLO, the lateral retinaculum (LR), and the anterior fibers of the iliotibial tract (ITT) were sequentially divided from the lateral border of the patella. Each was temporarily reattached to a cuff of soft tissue left on the patella using surgical clamps to determine its contribution to lateral restraint. The VLO was found to be the primary restraint in one-half of the knees. In one-third of the knees, all three of the structures contributed equally. In six knees, the primary restraint was the anterior fibers of the ITT, whereas the LR was the primary restraint in only two. The distal ends of these three structures were then resected to prevent rescarring and retethering. At a minimum follow-up period of two years, 87% had satisfactory relief of their patellar pain, had returned to normal activities, and had no or minimal physical findings of LFS. The procedure is recommended for patients who have failed other procedures and in those whose symptoms cannot be controlled by activity modification, exercises, bracing, or medication.