Anteromedial tibial tubercle transfer in patients with chronic anterior knee pain and a subluxation-type patellar malalignment

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 angle >20 degrees, tilt angle >8 degrees) and were treated with an isolated anteromedial tibial tubercle transfer. Fifteen patients (Group 2) had combined subluxation and tilt malalignment (congruence angle >20 degrees, tilt angle <8 degrees) and underwent anteromedial tibial tubercle transfer combined with a lateral release. Pre- and postoperative evaluations included clinical and radiographic examinations, Lysholm and Kujala patellofemoral scores, and standing-alignment computed tomography scans in 15 degrees of flexion taken transversely at the midpatellar. In all but one patient a dramatic improvement in Lysholm and Kujala scores was noted. The congruence angle improved in all patients except one, with an average improvement of 16 degrees in Group 1 and of 14 degrees in Group 2. The tilt angle remained relatively unchanged (change, -0.5 degrees) in Group 1, but it improved by 11 degrees 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.