Progression of radiographic evidence of osteoarthritis following tibial plateau leveling osteotomy in dogs with cranial cruciate ligament rupture: 295 cases (2001-2005).

OBJECTIVE

To determine whether radiographic signs of osteoarthritis became progressively worse and tibial slope angle (TSA) changed substantially following tibial plateau leveling osteotomy for treatment of cranial cruciate ligament rupture in dogs.

DESIGN

Retrospective case series.

ANIMALS

295 dogs (373 stifle joints).

PROCEDURES

Medical records were reviewed. Radiographs obtained before and 8 weeks after surgery were used to determine the degenerative joint disease (DJD) score, calculated as the sum of individual scores (0 through 3) assigned to 30 radiographic factors. Radiographs obtained immediately and 8 weeks after surgery were used to measureTSA. For dogs that underwent bilateral surgery, data for the first joint treated were used in analyses. Data for the second joint treated in dogs that underwent bilateral surgery were analyzed separately.

RESULTS

A small, but significant, increase was found in mean DJD score 8 weeks after surgery, compared with mean preoperative score. An inverse relationship was found between preoperative DJD score and the difference between postoperative and preoperative DJD scores. Mean TSA 8 weeks after surgery was significantly higher than mean TSA immediately after surgery. Analysis of data for the second stifle joints in the 78 dogs that underwent bilateral surgery yielded similar results.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggested that there was a small, but measurable, increase in the severity of radiographic changes attributed to osteoarthritis in the stifle joints of dogs that underwent tibial plateau leveling osteotomy because of cranial cruciate ligament rupture.