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The optimal surgical intervention for lateral patellar instability remains a topic of controversy despite satisfactory clinical outcomes and low re‐dislocation rates reported in numerous studies following medial patellofemoral ligament reconstruction (MPFLR) with and without tibial tubercle transfer (TTT). The purpose of this systematic review and meta‐analysis is to investigate the hypothesis that combining MPFLR with TTT provides reduced complication rates and improved clinical outcomes to isolated MPFLR in patients with lateral patellar instability. We conducted a comprehensive systematic review and meta‐analysis of comparative trials involving MPFLR with and without TTT, sourcing data from PubMed, the Cochrane Library, Embase, and Web of Science. The primary clinical outcomes analyzed included the Kujala score, the Lysholm score, complication rates, and the Caton–Deschamps index (CDI). Random or fixed effects were used for the meta‐analysis. Postoperatively, there were no significant differences observed in the Kujala and Lysholm scores between MPFLR and MPFLR + TTT (p = 0.053). At the final follow‐up, the CDI had decreased 0.015 (95% CI −0.044, 0.013; p = 0.289) points in the MPFLR group, with no statistical significance. In contrast, the MPFLR + TTT group demonstrated a significant decrease of 0.207 (95% CI −0.240, −0.174; p = 0.000) points in CDI. Notably, the complication rate was higher in the MPFLR + TTT group compared to the MPFLR‐only group (RR = 2.472; 95% CI 1.638, 3.731; p = 0.000). Both MPFLR and MPFLR + TTT procedures yield significant improvements in the Kujala and Lysholm scores. However, the MPFLR + TTT approach results in an apparent improvement in CDI and corrects patellar maltracking, particularly in cases involving high tibial tuberosity‐trochlear groove (TT‐TG) (>20 mm) or patella alta (CDI > 1.2), while MPFLR alone cannot. It is essential to consider the higher complication rate of MPFLR + TTT, which suggests that MPFLR alone may be sufficient for patients without high TT‐TG or patella alta. [ABSTRACT FROM AUTHOR]

Objective: The tibial tubercle‐trochlear groove (TT‐TG) distance is now routinely utilized to help determine whether a realignment procedure is necessary for patients with patellar instability. The tibial tubercle‐posterior cruciate ligament (TT‐PCL) distance has been explored as an alternative measurement. The aim of this study is to compare the reliability of TT‐TG and TT‐PCL; to explore whether there is a relationship between the TT‐PCL and the TT‐TG distance; to determine whether there is a relationship between the TT‐TG and TT‐PCL distances and knee rotation; and to compare the abilities of the TT‐PCL distance and the TT‐TG distance with predicted patellar instability. Method: This systematic review was performed in accordance with PRISMA guidelines. Three databases, PubMed, EMBASE, and Cochrane Central Register of Controlled Trials, were searched from inception to September 2021 to identify clinical studies comparing TT‐TG and TT‐PCL distances to patellar instability. Data on patient baseline characteristics, TT‐TG and TT‐PCL distances, inter‐observer reliability, and area under the receiver‐operating characteristic curve (AUC) were recorded. The methodological quality of the studies was assessed using the quality assessment form recommended by the Agency for Healthcare Research and Quality (AHRQ). Result: Twenty studies were included in the final analysis, comprising 2330 knees from 2260 patients. The current study showed that TT‐TG and TT‐PCL have similar observer reliability. The inter‐ and intra‐observer reliability of TT‐TG ranged from 0.807 to 0.98 and 0.553 to 0.99, respectively. The inter‐ and intra‐observer reliability of TT‐PCL ranged from 0.553 to 0.99 and 0.88 to 0.981, respectively. Six studies compared the AUC for predicting patellar instability and showed that TT‐TG had better predictive performance than TT‐PCL. Three studies reported a correlation between TT‐TG and knee rotation, but no such relationship was found for TT‐PCL. Eight studies reported a weak or moderate correlation between TT‐TG and TT‐PCL. Conclusion: TT‐TG and TT‐PCL have similar inter‐ and intra‐rater reliability (as measured by ICC), but TT‐TG has greater discriminatory power to predict patellar instability than TT‐PCL (as measured by AUC values and odds ratio). However, considering trochlear dysplasia and individual variations, future studies need to find more accurate and individualized methods to predict patellar instability. [ABSTRACT FROM AUTHOR]