A COMPARISON OF 2 SURGICAL APPROACHES TO THE SCAPULOHUMERAL JOINT IN DOGS

Two scapulohumeral arthrotomy techniques were evaluated and compared i n 10 normal, young adult greyhounds. A caudolateral approach with cran iodorsal retraction of the teres minor muscle (no-tenotomy) and a cran iolateral approach with tenotomy of the infraspinatus tendon were each performed unilaterally in 5 dogs. The dogs were evaluated using force plate gait analysis, lameness evaluation, radiography, and goniometry for 5 weeks and then euthanatized. Tenotomy sites and sections of the humeral articular cartilage were collected from shoulder joints that had been operated on and examined microscopically. The same surgical a pproach was then performed on the contralateral shoulder in the cadave rs and exposure of the humeral articular cartilage was measured using planimetry. Peak vertical force applied to the operated limbs in the t enotomy group was significantly less than preoperative levels on day 3 and significantly less than the notenotomy group on days 21 and 28. T he peak vertical force applied to the operated limbs in the no-tenotom y group was not significantly different from preoperative levels durin g the study. Scapulohumeral arthrotomy by tenotomy of the infraspinatu s resulted in decreased range-of-motion and joint extension compared w ith joints operated on without tenotomies, but provided significantly greater exposure to the articular surface. Scapulohumeral arthrotomy w ith craniodorsal retraction of the teres minor muscle did not signific antly alter goniometric measurements compared with unoperated joints. Both techniques resulted in similar subjective lameness scores and cau sed no gross microscopic or radiographic evidence of articular cartila ge damage. (C)Copyright 1995 by The American College of veterinary sur geons