Diagnosis and management of equine hock collateral ligament injuries

This report caught my eye because of the surprising difficulty of diagnosing collateral ligament injury and the fair to good prognosis with conservative management. You would think that such injuries would have obvious signs referring to the collateral ligaments of the hock but not so. Instead, remarkable lameness and generalized swelling of the hock, including joint capsule distension, have been the typical signs. Also apparent in the article is that while ultrasound is the way to diagnose these lesions, it requires skill and experience because of the complicated nature of the soft tissues in these regions. Taken from the summary: “Although uncommon, these lesions should be considered in the differential diagnosis of a swollen hock with associated lameness, emphasizing the importance of a careful clinical and ultrasonographic examination for a correct diagnosis and appropriate management.”
DrO

Conservative management of equine tarsal collateral ligament injuries may allow return to normal performance
J Am Vet Med Assoc. 2023 Apr 11;1-9. doi: 10.2460/javma.22.12.0597. Online ahead of print.
Authors
Claudia Fraschetto 1 , Michaël Dancot 2 , Maxime Vandersmissen 2 , Jean-Marie Denoix 1 , Virginie Coudry 1
Affiliations

1 1Center of Imaging and Research on the Equine Locomotor Injuries, Normandie Equine Vallée, Goustranville, France.
2 2Diagnostic Imaging Unit, Faculty of Veterinary Medicine, University of Liège, Liège, Belgium.

Abstract

Objective: To describe type and distribution of tarsal collateral ligament (CL) injuries and to assess the long-term outcome in horses treated conservatively.

Animals: 78 horses (median age, 7 years [IQR, 4 to 9.75 years]) of different breeds and disciplines.

Procedures: Retrospective analysis (2000 through 2020) of horses with tarsal CL lesions diagnosed on ultrasound. The resting time, ability to return to work, and performance level after the injury were compared between horses having a single ligament (group S) or multiple ligaments (group M) affected and according to the case severity.

Results: Most of the horses (57/78) presented a single CL injury, while 21 had multiple CLs affected simultaneously, for a total of 108 CLs injured and 111 lesions. In both groups, the short lateral CL (SLCL) was the most commonly affected (44/108), followed by the long medial CL (LMCL; 27/108). Enthesopathies (72.1%) were more frequent than desmopathies alone (27.9%) and involved mostly the proximal insertion of the SLCL and the distal attachment of the LMCL. Conservative treatment (n = 62) consisted mainly of stall rest. The median resting time (120 days [IQR, 60 to 180 days]) did not significantly differ between the 2 groups (group S vs M) or according to the severity. Most horses (50/62) were able to return to work within 6 months. Horses that did not return (12/62) were more likely to have severe lesions (P = .01). Thirty-eight horses were able to perform at a level equal to or higher than before the injury.

Clinical relevance: This study highlights the importance of thorough ultrasound assessment of tarsal CL injuries and demonstrates that conservative management is a viable option to allow these horses to return to previous performance level.