AOSSM/AANA Specialty Day 2020-Outcomes and Reoperation Rates After Tibial Tubercle Transfer and Medial Patellofemoral Ligament Reconstruction

Outcomes and Reoperation Rates After Tibial Tubercle Transfer and Medial Patellofemoral Ligament Reconstruction

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This retrospective case series evaluates outcomes and reoperation rates following medial patellofemoral ligament reconstruction (MPFLR), tibial tubercle transfer (TTT), and their combination in treating patellofemoral instability (PFI). Patellar instability affects an estimated 7 per 100,000 adults and 31 per 100,000 adolescents yearly, with recurrence rates of 30-60% reported in young patients. Factors contributing to instability include rotational deformity, valgus limb alignment, medial tissue incompetence, abnormal Q-angle, patella alta, and trochlear morphology.<br /><br />Data from 497 patients (65% female, average age 23) undergoing MPFLR, TTT, or combined procedures were analyzed, excluding patients with ACL/PCL injuries or unloading procedures. The overall reoperation rate was 24.5%, with 19.5% minor and 8% major reoperations; revision stabilization surgeries occurred in 5.8%. Reoperation was highest in isolated TTT cases (33.3%), significantly greater than MPFLR alone (18.5%) or combined procedures (26.2%) (p=0.007). The combined procedure group had the lowest rate of revision stabilization (3.85%). Logistic regression identified female sex (OR 2.23, p=0.0014) as a significant risk factor for reoperation; age and BMI were not significant.<br /><br />Bony anatomy influenced outcomes, with higher reoperation rates in patients with Dejour D trochlear dysplasia (29%) compared to A-C types (23%). Patella alta and trochlear dysplasia were also associated with higher recurrence risk. Patient-reported outcomes, collected at a mean 4.7 years follow-up (56% response rate), showed no clear difference between reoperation and non-reoperation groups.<br /><br />Strengths include the study’s large single-center sample and stratification by bony morphology. Limitations include its retrospective design and potential responder bias. The findings indicate that isolated TTT has the highest reoperation risk, while combined MPFLR and TTT may offer better stability. Female sex, patella alta, and severe trochlear dysplasia are key risk factors for failure and warrant consideration in surgical planning. Lack of clear treatment algorithms highlights need for individualized approaches based on anatomy and risk profile.

Keywords

medial patellofemoral ligament reconstruction

tibial tubercle transfer

patellofemoral instability

reoperation rates

patella alta

trochlear dysplasia

rotational deformity

valgus limb alignment

risk factors

revision stabilization surgery