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. 2025 Nov 24;13(11):23259671251394040.
doi: 10.1177/23259671251394040. eCollection 2025 Nov.

Comparative Postoperative Changes Over Time in Patellar Height After Medial Patellofemoral Ligament Reconstruction With and Without Tibial Tubercle Osteotomy

Collin D R Hunter  1 , Benjamin T Johnson  1 , Anish Singh  1 , Madison Gardner  1 , Zoe D Trutner  1 , Stephen K Aoki  1 , Justin J Ernat  1
Affiliations

Comparative Postoperative Changes Over Time in Patellar Height After Medial Patellofemoral Ligament Reconstruction With and Without Tibial Tubercle Osteotomy

Collin D R Hunter et al. Orthop J Sports Med. .

Abstract

Background: The postoperative influence of medial patellofemoral ligament reconstruction (MPFLR)-performed alone or in conjunction with tibial tubercle osteotomy (MPFLR+TTO)-on patellar height is not well-understood.

Purpose/hypothesis: The purpose was to compare longitudinal changes in patellar height after MPFLR and MPFLR+TTO. It was hypothesized that knees undergoing MPFLR will experience a decrease in patellar height that is greater than that of knees undergoing MPFLR +TTO and that both cohorts will return to Caton-Deschamps index (CDI) measures near that of preoperative levels.

Study design: Cohort study; Level of evidence, 3.

Methods: This is a retrospective radiographic review of skeletally mature patients >15 years of age who underwent either an MPFLR or an MPFLR+TTO with lateral knee radiographs available from the preoperative period, 0 to 6 months (early) postoperatively, and >6 months (final) postoperatively. Exclusion criteria were (1) distalization TTO and (2) previous procedures, or procedures postoperatively near the extensor mechanism. CDI was used to quantify patellar height. Paired Student t tests and a repeated-measures analysis of variance was performed to evaluate the effect of CDI changes between MPFLR and MPFLR+TTO.

Results: A total of 62 knees in 61 patients (55% female [34/62 knees]) were included, with n = 27 knees undergoing MPFLR and n = 35 knees with MPFLR+TTO. Mean age was 25.9 ± 9.8 years (range, 15-58 years). Mean time from surgery to early postoperative imaging was 1.9 ± 1.4 months with MPFLR and 2.4 ± 0.8 months with MPFLR+TTO (P = .08). Mean time from surgery to final follow-up imaging was 26.3 ± 24.6 months with MPFLR and 23.4 ± 17.8 months with MPFLR+TTO (P = .59). Preoperative mean CDI values were comparable between the MPFLR and MPFLR+TTO (1.15 ± 0.20 vs 1.18 ± 0.13; P = .13). At early follow-up (0-6 months postoperatively), mean CDI values with MPFLR decreased to 1.01 ± 0.18, compared with MPFLR+TTO at 1.11 ± 0.15 (P = .003). At final follow-up (>1 year postoperatively), the CDI values were similar between MPFLR (1.13 ± 0.21) and MPFLR+TTO (1.13 ± 0.14) (P = .79).

Conclusion: Our study showed that MPFLR both with and without TTO demonstrated an eventual return toward preoperative patellar height, yet they followed different early postoperative trajectories. MPFLR demonstrated an early decrease in patellar height that progressively relengthened over time, whereas MPFLR+TTO exhibited almost no changes in patellar height.

Keywords: Caton-Deschamps; medial patellofemoral ligament reconstruction; patellar height; tibial tubercle osteotomy.

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Conflict of interest statement

One or more of the authors has declared the following potential conflict of interest or source of funding: S.K.A. has received consulting fees from Stryker. J.J.E. has received consulting fees from Depuy Synthes Products and Medical Device Business Services, support for education from Arthrex and Smith & Nephew, and a grant from Arthrex. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto. Ethical approval for this study was obtained from the University of Utah (No. 00071733).

Figures

A X-ray image shows the knee with markers A and B indicating a measurement calculation for medical analysis.
Figure 1.
The Caton-Deschamps index (A/B) is defined as the ratio of (A) the length of the articular surface, and (B) the distance from the inferior edge of the patellar articular surface to the anterior superior edge of the tibial plateau.
Depicts CDI values in MPFLR vs MPLFRTTO surgeries at pre-op, early post-op, and final post-op, noting MPFLR's initial CDI drop and recovery, contrasted against MPFLR TTO’s stability. Statistical analysis shown.
Figure 2.
Caton-Deschamps index (CDI) values measured preoperatively, at early postoperative (0-6 months), and at final postoperative (>1 year) time points after isolated medial patellofemoral ligament reconstruction (MPFLR) compared with MPFLR combined with tibial tubercle osteotomy (MPFLR+TTO). The MPFLR cohort demonstrated a significant initial decrease in patellar height followed by a return toward preoperative levels, whereas the MPFLR+TTO group exhibited more stable CDI values across all measured intervals. Statistical significance was determined using paired t tests and repeated-measures analysis of variance (P < .05).
See this image and copyright information in PMC

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