Purpose

There remains controversy regarding the addition of tibial tubercle osteotomy (TTO) to medial patellofemoral reconstruction (MPFLR) in the setting of patella instability surgery. Our purpose was to evaluate the impact of performing a concomitant tibial tubercle osteotomy (TTO) with a medial patellofemoral ligament reconstruction (MPFLR) on post-operative complications, re-operations and costs up to two years following primary surgery. Our hypothesis was that concomitant TTO will not influence complication rates but will reduce re-operation rates at the expense of increased cost as compared to isolated MPFLR.

Methods

We queried the MarketScan database in order to identify patients who underwent primary MPFLR from 2007-2015. Patients were stratified into cohorts based on concomitant TTO performed on the same day as index MPFLR. To minimize the effect of potential confounding on the direct comparison of patients undergoing the two procedures, a propensity-score match (PSM) was utilized. A greedy nearest-neighbor algorithm was employed to match patient cohorts with a 7:1 MPFLR to MPFLR + TTO ratio. Reoperations, complications, and costs were followed for two years post-index procedure. Patients without laterality codes were excluded. Results were analyzed statistically.

Results

This study identified 968 patients who underwent primary MPFLR. Patients were stratified into two groups: 1) MPFLR only or 2) MPFLR + TTO. After matching the cohorts, mean age, sex distribution, and rates of baseline diabetes, hyperlipidemia, hypertension, tobacco use, and obesity were similar. Patients in the two cohorts experienced similar rates of post-operative complications (MPFLR + TTO: 9.9%, MPFLR: 8.7%, p= 0.6694). Rates of dislocation (MPFLR + TTO: 5.8%, MPFLR: 4.3%, p = 0.4434), stiffness (MPFLR + TTO: 0.8%, MPFLR: 2.5%, p = 0.2538), infection (MPFLR + TTO: 0.8%, MPFLR: 0.6%, p = 0.7559), and wound complication (MPFLR + TTO: 0.8% vs MPFLR: 0.8%, p = 1.000) were similarly low. Performing a concomitant TTO decreased revision surgery for instability (revision MPFLR) rates (6.6% vs 11.1%, p = 0.1327); however, this difference was not statistically significant. Hardware removal rates (MPFLR + TTO: 9.9%, MPFLR: 1.9%, p < 0.0001) were higher in the MPFLR + TTO cohort. Patients who underwent a concomitant TTO were associated with higher payments through 2 years of index surgery when compared to MPFLR only patients ($25,740 vs $17,727, p < 0.0001).

Conclusions

Concomitant TTO does not lead to increased post-operative complications following primary MPFLR; however, its performance may lead to increased healthcare resource utilization through 2-years of follow-up. Further research should investigate the impact of a concomitant TTO and MPFLR on long-term MPFL stability and failure rates.