# Comparative Radiographic Analysis of Trochleoplasties for Patellar Luxation Correction: Inter-Observer Agreement of a Modified Osteoarthritis Scoring System

## TL;DR

This study compared two surgical techniques for correcting patellar luxation in small dogs and found no major differences in osteoarthritis progression over time.

## Contribution

The study introduces a modified osteoarthritis scoring system with high inter-observer agreement for evaluating surgical outcomes in patellar luxation.

## Key findings

- Both surgical techniques showed increased osteoarthritis over time, with no significant differences between them.
- The modified OA scoring system proved reliable for tracking OA progression after surgery.
- TBR showed slightly worse outcomes in some cases, but overall results were not significantly different from TWR.

## Abstract

Patellar luxation is a common knee problem in small breed dogs, where the patella most often is displaced medially, often requiring surgery for a permanent stabilization. This study compares two surgical techniques in 25 small dogs with moderate to severe patellar luxation to see which technique led to better long-term outcomes. Radiographs were taken before and at least one year after surgery to track joint changes. Three experienced veterinarians reviewed the radiographs using a scoring system to evaluate osteoarthritis (OA) progression. The results revealed that the degree of osteoarthritis increased in both groups over time, but one group had slightly worse outcomes in some cases. Overall, no major differences were found between the two treatment options regarding the extent of osteoarthritis development. The scoring system used in this study proved to be useful for tracking OA progression after surgical treatment of patellar luxation. More research with larger groups of dogs and additional tests, such as movement analysis, are needed to better understand how surgery affects long-term outcomes.

Patellar luxation is common in small breed dogs and is often treated surgically. This study compares the long-term outcomes of two surgical techniques, trochlear wedge recession (TWR) and trochlear block recession (TBR), for medial patellar luxation (MPL) with regard to osteoarthritis (OA) progression. High inter-observer agreement was hypothesized for the use of a modified OA scoring system and fewer OA changes in the TBR group. This study included 25 dogs (<15 kg) with grade-2 or -3 MPLs treated at the University of Veterinary Medicine Vienna (2016–2021). A total of 32 stifle joints (TWR Group n = 11, TBR Group n = 21) were evaluated pre-operatively and at least one year post-operatively using a modified OA scoring system. A statistical analysis was conducted to compare OA progression between the techniques. The inter-observer agreement was high. The OA scores increased in both groups post-operatively, with TBR demonstrating a greater progression at specific points. Overall, no significant differences were found between the techniques. These findings suggest that OA progression does not significantly differ between TWR and TBR. The modified OA scoring system has shown to be reliable for assessing OA progression after treatment. Further prospective studies with larger study populations incorporating clinical assessments are needed for a better understanding of the surgical impacts on OA development.