Anteromedial Tibial Tubercle Transfer in Patients with Chronic Anterior Knee Pain and a Subluxation-Type Patellar Malalignment

Abstract

We performed a prospective analysis of 29 Fulkerson anteromedial tibial tubercle transfers in patients with chronic anterior knee pain. The average followup was 32 months (range, 25 to 44). Fourteen patients (Group 1) had subluxation-type malalignment (congruence an gle >20°, tilt angle >8°) and were treated with an isolated anteromedial tibial tubercle transfer. Fifteen patients (Group 2) had combined subluxation and tilt malalignment (congruence angle >20°, tilt angle <8°) and underwent anteromedial tibial tubercle transfer combined with a lateral release. Pre- and postopera tive evaluations included clinical and radiographic ex aminations, Lysholm and Kujala patellofemoral scores, and standing-alignment computed tomography scans in 15° of flexion taken transversely at the midpatellar. In all but one patient a dramatic improvement in Lysh olm and Kujala scores was noted. The congruence angle improved in all patients except one, with an average improvement of 16° in Group 1 and of 14° in Group 2. The tilt angle remained relatively unchanged (change, -0.5°) in Group 1, but it improved by 11 ° in Group 2. We conclude that an isolated anteromedial tibial tubercle transfer can consistently improve patellar subluxation and, when combined with a lateral release, can improve patellar subluxation and tilt, resulting in improved functional scores for patients with chronic anterior knee pain.