Desmitis of the distal digital annular ligament in seven horses: MRI diagnosis and surgical treatment.
OBJECTIVE
(1) To describe the clinical signs and abnormalities observed on magnetic resonance imaging (MRI) in 7 horses with desmitis of the distal digital annular ligament (DDAL); (2) to describe the normal magnetic resonance (MR) appearance and thickness of the DDAL in health; and (3) to describe a tenoscopic surgical technique for treating horses with desmitis of the DDAL.


METHODS
Retrospective study.


METHODS
Horses (n=7) with desmitis of the DDAL.


METHODS
MR examinations of 20 sound horses were reviewed to determine the normal appearance of the DDAL. Dimensions obtained from these images were compared with MR findings from 7 horses with DDAL desmitis. Desmitis of the DDAL was treated by tenoscopic surgery and outcome assessed.


RESULTS
Horses with DDAL desmitis had lameness (grade 2-3 out of 5) that improved after a palmar digital nerve block. The affected DDAL was enlarged and had an abnormal signal on MR images of the feet. After tenoscopy and DDAL transection, 5 horses returned to athletic performance, including 2 horses that failed to respond to medical treatment and rest before surgery.


CONCLUSIONS
Primary desmitis of the DDAL is a cause of lameness in horses. Transection of the DDAL allowed 5 horses with this injury to return to athletic performance.


CONCLUSIONS
DDAL desmitis should be included in the differential diagnoses of horses with lameness that improves after a palmar digital nerve block but have no abnormalities observed on radiographs of the feet. Tenoscopic surgical transection of the DDAL is an effective treatment for some horses.
Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman, WA, USA. cohenjm@vet.upenn.edu
Jennifer M
JM
Cohen
Robert K
RK
Schneider
Chad J
CJ
Zubrod
Sarah N
SN
Sampson
Russell L
RL
Tucker
D000818:Animals; D016022:Case-Control Studies; D003937:Diagnosis, Differential; D005260:Female; D006734:Horse Diseases / Q000175:diagnosis* / Q000601:surgery*; D006736:Horses; D008022:Ligaments / Q000473:pathology / Q000601:surgery*; D008279:Magnetic Resonance Imaging / Q000662:veterinary; D008297:Male; D012189:Retrospective Studies; D012720:Severity of Illness Index; D052256:Tendinopathy / Q000175:diagnosis / Q000601:surgery / Q000662:veterinary*; D016896:Treatment Outcome