AANA Lab Course 1002 -3rd Annual Fellows/Chief Residents-Tibial Tubercle Osteotomy, Questions

Tibial Tubercle Osteotomy, Questions – Aman Dhawan, M.D.

Pdf Summary

Dr. Aman Dhawan, an Associate Professor in Orthopaedics at Penn State Health, presented a detailed overview of Tibial Tubercle Osteotomy (TTO) for treating patellar instability. The case discussed involved a 26-year-old female with a decade-long history of recurrent, traumatic patellar instability unresponsive to bracing and physical therapy. Clinical findings included borderline hyperlaxity (Beighton score 4), a positive J sign, weak medial soft tissue restraints, normal patellar height, and a tibial tubercle-to-trochlear groove (TT-TG) distance of 21 mm on CT, indicating lateralization of the tibial tubercle.<br /><br />Indications for TTO include patellar instability with TT-TG distance over 20 mm, patella alta that may require distalization and medialization, and chondrosis or degenerative joint disease (DJD) of the patellofemoral joint, especially distal and lateral lesions. Contraindications include proximal or medial patellar lesions, advanced trochlear DJD, open tibial tubercle physes, and inflammatory arthritis.<br /><br />The surgical technique involves an initial knee arthroscopy for chondral assessment and lateral release, followed by an anteromedialization (AMZ) osteotomy creating a 7-8 cm tibial bone shingle with a distal hinge intact. The osteotomy is translated about 12-15 mm anteromedially to reduce retropatellar contact pressures by roughly 30%. Fixation is achieved with at least three bicortical screws, ensuring at least 50% bone contact to promote union. Postoperatively, patients remain toe-touch weight-bearing for six weeks and initiate range-of-motion exercises immediately to prevent stiffness, progressing to low-impact cardio at three months and full activity by 7-9 months.<br /><br />Key strategies to avoid complications include avoiding excessive anteriorization to prevent skin issues, meticulous surgical technique to prevent fractures, and pie-crusting the anterior compartment fascia to reduce compartment syndrome risk. Dr. Dhawan emphasized the importance of proper technique and rehabilitation to achieve successful outcomes in patellar instability management using TTO.

Keywords

Tibial Tubercle Osteotomy

Patellar Instability

TT-TG Distance

Anteromedialization Osteotomy

Patella Alta

Chondrosis

Degenerative Joint Disease

Knee Arthroscopy

Postoperative Rehabilitation

Complication Prevention