Relationship between mechanical thresholds and limb use in dogs with coxofemoral joint oa-associated pain and the modulating effects of pain alleviation from total hip replacement on mechanical thresholds.

Abstract

OBJECTIVES: To compare von Frey mechanical quantitative sensory thresholds (mQSTvF ) between pelvic limbs in dogs before unilateral total hip replacement (THR) surgery; to correlate ground reaction forces (GRF) with mQSTvF ; to assess changes in mQSTvF after THR surgery. STUDY DESIGN: Prospective clinical study. ANIMALS: Dogs (n = 44). METHODS: mQSTvF and GRF measured using a pressure sensitive walkway were evaluated before, and 3, 6, and 12 months after, unilateral THR. Measurements were recorded from the affected (operated) pelvic limb (APL) and the non-operated pelvic limb (NPL). Random effects analysis and forwards stepwise linear regression models were used to evaluate the influence of time since surgery and patient factors on mQSTvF thresholds. RESULTS: There were no significant correlations between mQSTvF data and age, bodyweight or the GRF variables. Preoperative mQSTvF measured at the APL and NPL did not differ (P = .909). mQSTvF thresholds increased significantly after 12 months in NPL (P = .047) and APL (P = .001). In addition to time, APL mQSTvF values were significantly affected by sex (higher in males, P = .010) and body condition score (higher in leaner dogs, P = .035) and NPL mQSTvF values by sex (P = .038). CONCLUSION: Successful unilateral THR results in decreased central sensitization after 12 months.