34th Annual Scientific Meeting proceedings

Objectives:

Arthroscopy is the gold standard for treating dorsal tarsocrural osteochondritis dissecans (OCD) but few surgeons routinely inspect the plantar joint pouch. This study aims to standardize joint evaluation by developing a wear-line scoring (WLS) system, to assess the accuracy of dorsal evaluations in representing total cartilage damage, and to explore associations among WLS and various parameters.

Methods:

Data were collected from horses undergoing arthroscopy for tarsocrural OCD treatment. Parameters included age, sex, breed, pre-operative joint effusion grade (0-3), inflammation grade (0-4), fragment size and location, and the presence of detached fragments or concurrent OC lesions. A WLS (0-3) was assigned to dorsal flexed (DF), dorsal extended (DE), and plantar (PL) lateral and medial talus ridges, together the total WLS. Statistical analyses included Spearman’s rank correlation and Wilcoxon signed-rank tests to compare different WLS. Regression models were used to explore associations between parameters.

Results:

A total of 225 joints were included. The PL WLS showed a strong correlation with total WLS (r=0,916; P<0.001) and was significantly higher than DF WLS and mean DF+DE WLS (P<0,001). Horses with inflammation grades >0 had increased odds of elevated effusion grade (P<0.001) and elevated WLS (P<0.05). OC lesions increased the likelihood of elevated WLS (P=0.027). Higher inflammation grades were linked to larger fragment sizes (P<0,001) and detached fragments (P=0.026).

Conclusions:

Routine arthroscopic assessment of the plantar tarsocrural pouch is recommend when treating dorsal lesions, as this provides a more accurate assessment of total joint wear. Future research should focus on clinical follow-up and prognosis.