Outcome and racing performance following standing fracture repair in 245 horses.

BACKGROUND: Repair of sagittal proximal phalanx (P1) and parasagittal metacarpal/metatarsal III (MC/MTIII) fractures has evolved over recent decades from a procedure carried out solely under general anaesthesia, to one commonly performed under standing sedation. To date, standing fracture repair has not been evaluated for large cohorts. OBJECTIVES: To determine short-term (survival to discharge) and long-term (return to racing) outcomes of horses undergoing standing repair of MC/MTIII and P1 fractures, and to compare pre-surgical and post-surgical racing performance. STUDY DESIGN: Single-centre retrospective cohort study. METHODS: Retrospective clinical record review of 245 cases undergoing standing repair of MC/MTIII or P1 fractures, 1 January 2007-30 June 2021. Data on signalment, fracture configuration and complications were collected and full race records were retrieved from the Racing Post Database (wwww.racingpost.com). Chi-squared and Mann-Whitney U tests were used to determine any difference in variables between horses that raced after surgery compared to those that did not. McNemar change and Wilcoxon signed-rank tests were used to compare pre- and post-surgical racing performance, p ≤ 0.05. RESULTS: Ninety-eight percent [95% confidence interval (CI): 96.2%-99.7%] of horses survived hospital discharge, and 75.1% (95% CI: 68.9%-81.4%) raced after surgery, a median of 241 days later. Horses that raced post-surgery were significantly less likely to have suffered from complications during hospitalisation than those that did not race again [17.3% (95% CI: 11%-24%) vs. 36.5% (95% CI: 23%-50%), p = 0.005]. Comparing pre- and post-operative racing performance, there was no significant difference in earnings per start [median £628.00, interquartile range (IQR) 115.90-1934.80 vs. £653.20, 51.00-1886.40, p = 0.7] or proportion of horses winning [51% (95% CI: 41%-61%) vs. 54% (95% CI: 44%-64%), p = 0.8] or being placed first-third [77% (95% CI: 68%-85%) vs. 71% (95% CI: 62%-80%, p = 0.5] in at least one race. MAIN LIMITATIONS: Retrospective nature of study with reliance on clinical records and public databases, limiting data available for analysis. CONCLUSIONS: Standing fracture repair is a viable treatment option for MC/MTIII or P1 fractures that returns horses to the racetrack within an acceptable time frame and is capable of restoring pre-surgical athletic ability.

Immediate pre-operative computed tomography for surgical planning of equine fracture repair: A retrospective review of 55 cases.

INTRODUCTION: Fracture configuration is often more complex than is radiographically appreciable. The objective of this study is to describe the influence of pre-operative computed tomography (CT) for surgical planning in a variety of fracture types. This has not been described in previous studies. MATERIALS AND METHODS: All cases with pre-operative radiographs, admitted for CT and surgical repair of a suspected limb fracture from January 2010-December 2020 were reviewed. CT was acquired under general anaesthesia in a multi-slice helical scanner; any surgery was then performed immediately. Three diplomates (two surgical; one diagnostic imaging) performed a blinded retrospective review of the radiographs and CT for each horse. A consensus decision was made on any change in surgical plan prior to and after CT review, and cases divided into three categories: CT of major, intermediate or minor relevance, as previously described by Genton et al, 2019. RESULTS: 55 cases were collated. Thoroughbred racehorses predominated. The median age was 3 years. A diverse range of fractures were presented: proximal phalanx (18/55), carpal (17/55), metacarpal/tarsal (11/55), sesamoid (5/55), tarsal (3/55), and middle phalanx (1/55). In 13 of 55 cases (23.6%, 95% CI[12%,35%]) CT was of major relevance. In 21 of 55 cases CT was of intermediate relevance (38.2%, 95% CI[25%,51%]). In 21 of 55 cases CT was of minor relevance (38.2%, 95% CI[25%,51%]). A Fisher's exact test demonstrated no statistical difference in CT relevance between fracture types (p<0.05). DISCUSSION/CONCLUSIONS: This study demonstrates that CT has a significant role in surgical planning, and in the majority (61.8%) of cases added additional information or significantly changed the surgical plan. In all cases CT ensured confidence in surgical planning.

Complications following equine sacroiliac region analgesia are uncommon: A study in 118 horses.

BACKGROUND: Diagnosis of sacroiliac region pain is supported by a positive response to sacroiliac region analgesia (SIRA). Varying techniques have been described for SIRA; with clinician preference often dictating method. Potential complications following SIRA include ataxia and recumbency. No study has specifically evaluated the prevalence of complications. OBJECTIVES: To describe the complication prevalence following SIRA in a referral clinic. STUDY DESIGN: Retrospective cohort study. METHODS: Review of records from horses presented to two of the authors at Rossdales, Newmarket, between January 2014 and December 2018, that underwent SIRA. Injection was performed using a blind midline approach with 20 mL mepivacaine (Intra-Epicaine 20mg/ml; Dechra) infiltrated through a straight 18 gauge 8.9cm spinal needle subdivided into four sub-locations per block. RESULTS: 118 horses were included, with 167 individual blocks. One horse showed a mild hindlimb gait abnormality following SIRA, which resolved uneventfully over 3 hours; complication rate 1/118 horses (0.85%; 95% CI: 0,2.5%), 1/167 joints (0.60%; 95% CI: 0,1.8%). SIRA subjectively improved lameness/performance in 132/167 (79%) joints. 49/118 (42%) received bilateral SIRA with 53/118 (45%) evaluated ridden following SIRA. MAIN LIMITATIONS: Small population numbers with low complication prevalence rate. CONCLUSIONS: SIRA, using the described technique, has a low (0.85%) prevalence of complications.

A lateral approach for screw repair in lag fashion of spiral third metacarpal and metatarsal medial condylar fractures in horses.

OBJECTIVE: To describe a lateral approach for screw fixation in lag fashion of simple spiral medial condylar fractures of the third metacarpus/metatarsus (MC3/MT3). STUDY DESIGN: Case series. ANIMALS: Thoroughbred racehorses (n=9). METHODS: Nondisplaced medial MC3/MT3 condylar fractures (3 thoracic, 6 pelvic limbs), with mean length 126 mm (range, 91-151 mm) were repaired by internal fixation, under general anesthesia, using multiple 4.5 mm cortical screws inserted in lag fashion from the lateral aspect of the limb, using radiographic or fluoroscopic guidance. Horses were recovered from anesthesia in half-limb casts; 7 unassisted and 2 using a rope-recovery system. Horses had 2 months box rest, 1 month in-hand walking, and follow-up radiographic examination at 3 months. RESULTS: Horses recovered uneventfully from anesthesia. Five horses raced; 1 returned to training, was persistently lame, and was retired to stud; 2 were retired directly to stud; and 1 horse was lost to follow-up. CONCLUSIONS: MC3/MT3 medial condylar fractures were successfully repaired by screws inserted n lag fashion form the lateral aspect. CLINICAL RELEVANCE: Use of a lateral approach to medial condylar MC3/MT3 fractures allows screw insertion perpendicular to the fracture plane without interference with palmar/plantar soft tissue structures or from the splint bones. Although repair was performed under general anesthesia, the technique should be adaptable to application in standing horses.