Supratuberositary tibial deformational osteotomy: For patellofemoral instability due to excessive tibial torsion

Background: Patellofemoral instability is a multifactorial condition often associated with coronal malalignment, trochlear dysplasia, and increased tibial tuberosity–trochlear groove (TT-TG) distance. While medial patellofemoral ligament reconstruction and tibial tubercle osteotomy are common, excessive external tibial torsion is an under-recognized contributor to recurrent instability and persistent anterior knee pain.

Objective: This article describes the indications, preoperative imaging protocols, and surgical technique for supratuberositary tibial derotational osteotomy to address patellofemoral maltracking.

Key Points: Surgical intervention is indicated for symptomatic patients with external tibial torsion exceeding 40° and a TT-TG distance greater than 20 mm. Preoperative assessment requires a CT rotational profile to measure femoral anteversion, knee rotation, and tibial torsion. The procedure involves an anterolateral approach distal to Gerdy’s tubercle, followed by a transverse osteotomy proximal to the tibial tubercle. Intraoperative correction is guided by Schanz pins and a sterile goniometer, with an estimated 0.7 mm reduction in TT-TG distance for every 1° of derotation. Fixation is achieved using lateral compression staples or specifically designed plates. Potential risks include the need for fibular osteotomy when corrections exceed 15° and the requirement for peroneal nerve neurolysis in high-degree rotations. Postoperative protocols emphasize immediate mobilization and progressive weight bearing to mitigate arthrofibrosis.

Conclusion: Supratuberositary tibial derotational osteotomy is an effective technique for correcting patellofemoral instability in the presence of significant torsional deformities. Precise preoperative planning and intraoperative alignment are essential to restore joint mechanics and improve clinical outcomes.