New York State College of Veterinary Medicine, University of Cornell, Ithaca, New York 14853, USA.
Collateral desmitis of the distal interphalangeal joint in 18 horses (2001–2002)
Article first published online: 5 JAN 2010
2004 EVJ Ltd
Equine Veterinary Journal
Volume 36, Issue 2, pages 160–166, March 2004
How to Cite
Dyson, S. J., Murray, R., Schramme, M. and Branch, M. (2004), Collateral desmitis of the distal interphalangeal joint in 18 horses (2001–2002). Equine Veterinary Journal, 36: 160–166. doi: 10.2746/0425164044868693
- Issue published online: 5 JAN 2010
- Article first published online: 5 JAN 2010
- Paper received for publication 17.04.03; Accepted 12.06.03
- collateral ligament;
- distal interphalangeal joint;
Reasons for performing study: There have been no previously published case series of horses examined using either scintigraphy or MRI to diagnose collateral ligament injuries not detectable using ultrasonography or radiography, nor have other concurrent soft tissue lesions been described.
Objectives: To describe the clinical features of horses with desmitis of the collateral ligaments of the distal interphalangeal (DIP) joint and to evaluate the results of radiographic, ultrasonographic, scintigraphic and magnetic resonance imaging (MRI) examinations.
Methods: Horses were examined between January 2001 and January 2003 and were selected for inclusion in the study if there was unequivocal evidence of collateral desmitis of the DIP joint based on ultrasonography or MRI. Subject details, case history, results of clinical examination and responses to local analgesic techniques were reviewed. The results of radiographic, ultrasonographic, scintigraphic and MRI examinations were assessed.
Results: Eighteen horses were identified with desmitis of a collateral ligament of the DIP joint, 3 horses (Group I) based on ultrasonography alone, 7 (Group II) with positive ultrasonographic and magnetic resonance images and 8 (Group III) with no lesion detectable using ultrasonography, but lesions identified using MRI. Seventeen horses had forelimb injuries and one a hindlimb injury. The medial collateral ligament was injured most frequently (13 horses). In the majority of horses, no localising clinical signs were seen. Lameness was invariably worse in circles compared with straight lines. Lameness was improved by palmar digital analgesia in 16 horses (87%), but only 6 were nonlame. Intra-articular analgesia of the DIP joint produced improvement in lameness in 6/15 horses (40%). In 16 horses, no radiographic abnormality related to the DIP joint or collateral ligament attachments was identified. Eight of 14 horses (57%) had focal, moderately or intensely increased radiopharmaceutical uptake (IRU) at the site of insertion of the injured collateral ligament on the distal phalanx. Alteration in size and signal in the injured collateral ligament was identified using MRI. In addition, 5 horses had abnormal mineralisation and fluid in the distal phalanx at the insertion of the ligament. Eleven horses had concurrent soft tissue injuries involving the deep digital flexor tendon, distal sesamoidean impar ligament, navicular bursa or collateral ligament of the navicular bone.
Conclusions and potential relevance: Collateral desmitis of the DIP joint should be considered as a cause of foot lameness. Although some injuries are detectable ultrasonographically, false negative results occur. Focal IRU at the ligament insertion on the distal phalanx may be indicative of injury in some horses. MRI is useful for both characterisation of the injury and identification of any concurrent injuries. Further follow-up information is required to determine factors influencing prognosis.;