Clinical signs and results of treatment in cats with patellar luxation: 42 cases (1992-2002).
OBJECTIVE
To describe clinical signs and results of treatment in cats with patellar luxation.


METHODS
Retrospective case series.


METHODS
42 cats in which patellar luxation had been diagnosed on the basis of results of palpation of the stifle joints.


METHODS
Degree of luxation was graded on a scale from 1 to 4, and severity of lameness was graded on a scale from 0 to 5. Radiographs of stifle joints were evaluated for signs of osteoarthritis. Long-term function was classified as poor, fair, good, or excellent.


RESULTS
34 cats had bilateral luxation and 8 had unilateral luxation. Only 7 (17%) cats had a history of trauma. Mean age of the cats was 3.3 years, and mean weight was 4.26 kg (9.4 lb); 26 (62%) were domestic shorthairs. Seventy-three of the 76 (95%) affected joints had medial patellar luxation. Luxation grades could be assigned to 65 joints, with grade 2 (30 joints) and 3 (22 joints) luxation being most common. Lameness grades could be assigned to 73 joints, with grade 1 lameness (27 joints) most common. Outcome was excellent for 8 of 17 joints treated without surgery and for 23 of 35 joints treated surgically. Complications attributable to surgery were reported in 8 cats.


CONCLUSIONS
Patellar luxation should be considered as a cause of hind limb lameness in cats. Low-grade luxation can be associated with lameness of the same severity as high-grade luxation. Surgical correction of patellar luxation in cats with grade 2 or 3 lameness can result in a favorable outcome.
Loughin
Catherine A
CA
Long Island Veterinary Specialists, 163 S Service Rd, Plainview, NY 11803, USA.
Kerwin
Sharon C
SC
Hosgood
Giselle
G
Ringwood
P Brendon
PB
Williams
Jamie
J
Stefanacci
Joseph D
JD
McCarthy
Robert J
RJ
D000818:Animals; D002371:Cat Diseases / Q000473:pathology / Q000601:surgery*; D002415:Cats; D005260:Female; D007794:Lameness, Animal / Q000209:etiology / Q000601:surgery; D008297:Male; D010003:Osteoarthritis / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000473:pathology / Q000662:veterinary; D031222:Patellar Dislocation / Q000473:pathology / Q000601:surgery / Q000662:veterinary*; D011859:Radiography; D016059:Range of Motion, Articular; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013264:Stifle / Q000601:surgery*; D016896:Treatment Outcome