title: Radiographic and arthroscopic findings associated with subchondral lucency of the distal radial carpal bone in 71 horses.
abstract: Case records and radiographs of 71 horses with subchondral lucency, without radiographic evidence of fracture, located on the distal radial carpal bone were examined retrospectively. All horses had lameness and/or joint effusion referable to the carpus. Distal radial carpal bone subchondral lucency was found as a solitary lesion or as a lesion concurrent and symmetric to a contralateral distal radial carpal bone chip fracture. The lesion appeared radiographically as a lucency or shadow on the distal dorsal margin of the radial carpal bone and was most evident on the flexed lateromedial and dorsolateral-palmaromedial oblique projections. Sixty-four joints in 55 horses underwent arthroscopic surgery. Surgical findings included osteochondral fragmentation in 44 joints, cartilage fragmentation with subchondral bone softening in 17 joints and cartilage fraying in 3 joints. Corresponding third carpal bone lesions were observed in 18 joints and moderate to severe synovitis was present in 24 joints. Carpal bone subchondral radiolucency without a fracture fragment observed on radiographs indicated cartilage and bone damage. In some cases, small chip fractures (1-2 mm) were present within the cartilage debris examined at surgery, yet were not radiographically visible. Follow-up information was obtained on 50 of the operated horses and 14 nonoperated horses. Forty (80%) of the surgically treated horses returned to racing, with 34 (68%) of these horses (20 of 26 with subchondral lucency as a solitary lesion) racing at a level of competition equal to or better than the pre-injury level. Of the 14 horses which were not operated, 6 (42%) returned to racing of which only 2 (14%) raced at the same pre-injury level of competition. Radiographic evidence of radial or intermediate carpal bone subchondral lucency is an indication of cartilage and bone damage which is best treated with arthroscopic surgery.
authors.affiliation: Marion duPont Scott Equine Medical Center, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Leesburg 22075, USA.
authors.forename: R M
authors.initials: RM
authors.lastname: Dabareiner
authors.forename: N A
authors.initials: NA
authors.lastname: White
authors.forename: K E
authors.initials: KE
authors.lastname: Sullins
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use; D001182:Arthroscopy / Q000379:methods / Q000662:veterinary; D001847:Bone Diseases / Q000473:pathology / Q000662:veterinary*; D002350:Carpus, Animal / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D005260:Female; D006734:Horse Diseases / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000628:therapy; D006736:Horses; D006820:Hyaluronic Acid / Q000627:therapeutic use; D008297:Male; D011859:Radiography; D012189:Retrospective Studies; D013585:Synovitis / Q000000981:diagnostic imaging / Q000473:pathology / Q000662:veterinary; D016896:Treatment Outcome
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D006820:Hyaluronic Acid