Minimal Reduction in Patellar Height Following Anteromedializing Tibial Tubercle Osteotomy With Medial Patellofemoral Ligament Reconstruction

Purpose To assess whether anteromedializing tibial tubercle osteotomy (AMZ TTO) results in reduction in patellar height when performed alongside medial patellofemoral ligament reconstruction (MPFLR) for the treatment of patellar instability. Methods We performed a retrospective review of patients who underwent AMZ TTO with MPFLR between 2017 and 2024. Patients were included if they had recurrent patellar instability, underwent AMZ without intentional distalization, and had preoperative and postoperative perfect lateral radiographs obtained between 20° and 40° of flexion. A minimum postoperative radiographic follow‐up of 1 week was required. Patellar height was measured using the Caton‐Deschamps Index (CDI). Further comparisons were done based on patients’ quadriceps status at their postoperative visit, grouped by the ability to perform a straight leg raise (SLR). Results A total of 33 knees met inclusion criteria. There were 4 (12%) male patients and 29 (88%) female patients. The left knee was involved in 18 (55%). The mean age was 26.49 ± 10.7 years. The mean body mass index was 25.68 ± 5.64. Patients’ preoperative and postoperative CDIs were measured an average of 109 (13‐239) days before and 76 (13‐221) days after surgery, respectively. Following AMZ TTO and MPFLR, the mean CDI significantly decreased from 1.11 to 1.07 (Δ = −0.037 ± 0.06, P = .002). Patients with preoperative patella alta (N = 8) had a significant reduction in CDI (1.29‐1.23, Δ = −0.056 ± 0.050, P = .02), whereas the difference was not significant for those without preoperative patella alta (1.05‐1.02, Δ = −0.031 ± 0.068, P = .05). No significant difference was found in preoperative to postoperative CDI change between the 2 groups ( P = .22). CDI change was compared across 3 groups based on SLR ability: normal SLR, SLR with extensor lag, and unable to SLR. No significant difference was found by analysis of variance, and post hoc Tukey's tests also showed no significant pairwise differences (all P > .05). Conclusions AMZ TTO performed with concomitant MPFLR and without intentional distalization produced a small but statistically significant early decrease in CDI that is unlikely to be clinically meaningful. Level of Evidence Level IV, retrospective therapeutic case series.