Background: There has been recent debate regarding the optimal surgical management strategy for recurrent patellofemoral instability in the presence of an increased tibial tuberosity-trochlear groove (TT-TG) distance. In particular, performing a combined tibial tuberosity osteotomy (TTO) and medial patellofemoral ligament reconstruction (MPFLR) for patients with a TT-TG >20 mm has been questioned, with the hypothesis that an isolated MPFLR (iMPFLR) would be just as effective.
Purpose: To pool and compare outcomes after MPFLR+TTO versus iMPFLR in patients with a TT-TG >20 mm.
Study design: Systematic review; Level of evidence, 4.
Methods: PubMed-MEDLINE, Embase, Web of Science, and Cochrane Central were searched, and a systematic review was performed. Included were studies that reported postoperative redislocation rates and/or functional outcome scores for patients with recurrent patellar instability and a TT-TG >20 mm who underwent either MPFLR+TTO or iMPFLR and had minimum 2-year follow-up data. Methodologic quality was assessed using the modified Coleman Methodology Score (mCMS). A proportional meta-analysis comparing redislocation, subjective instability, and total complication rates was performed, and mean postoperative functional outcome scores were pooled using a random-effects model with a restricted maximum likelihood estimator.
Results: In total, 1548 studies were screened, from which 13 were included for analysis. Of the 386 included patients (406 knees), 276 underwent MPFLR+TTO and 110 underwent iMPFLR. The mean mCMS was 61.3 ± 10.5 (range, 48-77). The pooled postoperative redislocation rate was 1.22% (95% CI, 0.22%-7%), with no significant difference between the study groups (P = .9995). The pooled complication rate was 10.17% (95% CI, 6.2%-16.3%) with no difference between groups (P = .9275), although the MPFLR+TTO group had higher heterogeneity in complication rates (I2 = 79.4%) compared with iMPFLR (I2 = 0%). There was no group difference in the pooled postoperative Lysholm scores (P = .5177), but patients who underwent iMPFLR had significantly higher postoperative Kujala scores compared with those who underwent MPFLR+TTO (P = .0283).
Conclusion: Even in the presence of previously indicative anatomic factors (TT-TG >20 mm), TTO combined with MPFLR does not seem to confer additional benefit compared with iMPFLR. This finding could be advantageous in minimizing the burden of additional surgery with its associated risks. The study findings should, however, be interpreted with caution given the heterogeneity of the studies.
Keywords: MPFL; TT-TG; TTO; knee; meta-analysis; patellofemoral instability.
© The Author(s) 2023.