Long-term effects of tibial plateau leveling osteotomy and tibial tuberosity advancement on tibial plateau subchondral bone density in dogs.

OBJECTIVE

To evaluate long-term loading patterns using subchondral bone density (SBD) distribution of the tibial plateau after tibial plateau leveling osteotomy (TPLO) and tibial tuberosity advancement (TTA).

STUDY

DESIGN

Cross-sectional study.

ANIMALS: Adult (> 2 years), medium to large breed dogs (>20 kg) that had been treated with TPLO or TTA at least 1 year prior to the study were recruited. A normal cohort of similar age and weight dogs with normal physical and orthopedic examinations served as control.

METHODS

Dogs were sedated for computed tomography (CT) of the stifle, and DICOM (digital imaging and communications in medicine) files were processed for CT osteoabsorptiometry (CTOAM). Tibial plateaus were sampled at 6 zones, and CTOAM was used to determine regional and maximal areas of SBD as a marker of joint loading.

RESULTS

Data were collected on 48 stifles in 31 dogs (15 TPLO, 11 TTA, 22 control). Lower Hounsfield unit (HU) values were measured in the caudal and mid-region of the lateral tibial plateau after TPLO and compared to normal. HU values did not differ between joints treated with TTA and those in the control group.

CONCLUSION

TPLO may alter stifle load distribution relative to the normal control group. There were no differences between TTA and the control group.

CLINICAL SIGNIFICANCE/IMPACT: Despite ongoing osteoarthritis (OA) in dogs after surgical intervention for cranial cruciate disease, changes in tibial SBD are minor and may not correlate with clinical function.