Non-surgical and surgical management of metacarpo/metatarsophalangeal joint dorsal chip fracture in the Thoroughbred racehorse.

Background Arthroscopy is considered the treatment of choice for dorsal osteochondral chip fractures of the metacarpo/metatarsophalangeal (MCP/MTP) joints in the racehorse; however, there is no published research on non-surgical management of this injury. Objectives To compare clinical features, intra-articular medication use and return to racing in Thoroughbred racehorses with non-surgically (non-SX) or surgically (SX) managed MCP/MTP dorsal chip fracture. Study design Retrospective observational study conducted between 2006 and 2014. Methods Radiographs of Thoroughbred racehorses were reviewed to identify MCP/MTP dorsal osteochondral chip fractures. Clinical and intra-articular medication data were obtained from veterinary records, and return to racing data from a public online resource. Results A total of 98 MCP/MTP horses with dorsal chip fractures were identified (70 non-SX, 28 SX). Median age was 2 years (range 2-7 years). Osteochondral chip fractures predominantly involved the forelimbs (n = 92, 93.9%) and the majority were considered by the treating clinician to be clinically active (n = 85, 86.7%). Significantly more SX horses had a reported ongoing problem associated with the affected joint than non-SX horses (P = 0.002), however there was no significant difference between non-SX and SX horses in the number of intra-articular medications of affected joint per month of follow-up (P = 0.22). The proportion of horses racing post-diagnosis was not significantly different between non-SX (55/70; 78.6%, 95% CI 69.0, 88.2%) and SX horses (24/28; 85.7%, 95% CI 72.8, 98.73%) (P = 0.57). Median time to first start following diagnosis for non-SX (106 days, range 1-326) was significantly shorter than for SX horses (203 days, range 9-559) (P = 0.002). Main limitations Management technique was not randomised or blinded, with few surgically managed horses. Conclusions The results contribute to the current evidence base used to guide management of osteochondral chip fractures of the MCP/MTP joints in the racehorse, and indicate that non-surgical management may be a valid treatment option for some injuries.