Clinical features, diagnostic imaging findings and concurrent injuries in 71 sports horses with suspensory branch injuries

Abstract

SummaryThere are limited data concerning suspensory ligament branch (SLB) injuries in sports horses. This retrospective study aimed to describe the limb and mediolateral distribution of SLB injuries, the case history of injured horses, clinical signs, response to diagnostic analgesia, presence of other injuries, ultrasonographic features, radiological abnormalities and outcome. Case records of sports horses with ultrasonographic evidence of SLB injury (1998–2012) were reviewed. Ultrasonographic images were assessed subjectively and objectively. Descriptive statistics were used to describe horse data and injury distribution. Pearson's Chi‐square tests were used to test sidedness, forelimbs and hindlimbs, and medial and lateral branches. Pearson's Chi‐square tests were used to test for the ability to detect SLB enlargement by palpation and ultrasonography. Seventy‐one horses had injuries in 88 limbs, 42 forelimbs and 46 hindlimbs; 39/71 (54.9%) horses with only one branch injured, 18 (25.3%) with 2, 3 (4.2%) with 3, and 11 (15.5%) with 4. There was no significant difference in the proportion of injured medial and lateral branches, forelimbs or hindlimbs, left fore vs. right fore, or left hind vs. right hind. Forelimb injuries were overrepresented in event horses (76.2%) and hindlimb injuries in dressage horses (87.1%). Twenty‐eight horses had primary SLB injuries; 43 had other concurrent injuries in the same limb, 23 involving the suspensory apparatus. There was a significant difference (P = 0.011 in the ability to detect palpable enlargement of an SLB (60/171, 35.1%), compared with enlargement detected ultrasonographically (111/171, 64.9%). Periligamentous fibrosis was present in 78.7% of injured hindlimb SLBs and in 35.8% of forelimbs. Of horses with primary SLB injuries, 43.5% returned to full athletic function at their previous level for at least one year and up to 5 years. Periligamentous fibrosis or hyperextension of the fetlock adversely influenced outcome.