Evaluation of a joint distractor to facilitate arthroscopy of the hip joint in dogs.

ABSTRACT

OBJECTIVE: To evaluate the technical feasibility and efficacy of a hip joint distraction technique, any potential ligamentous damage linked to the procedure, and the effect of joint venting on the maximum distraction achieved. METHODS: Twenty hip joints from 11 canine cadavers were evaluated radiographically by standard and stressed projections. Joint distraction was applied with loads from 40 up to 200 N, in 40 N increments, and fluoroscopic images were obtained at each load. At 200 N, a needle was inserted into the joint to achieve a venting effect, and the space was measured again. Standard and stressed radiographs were performed to evaluate potential laxity changes. RESULTS: Distraction caused a significant increase in joint space at each load of distraction, although there were some variations. Joint venting produced a significant increase in joint space. A statistically significant difference in joint laxity evaluated radiographically before and after the procedure was recorded. CLINICAL SIGNIFICANCE: Use of the distraction apparatus resulted in an increase in joint space. This could be useful for clinical situations where a larger joint space is required such as for arthroscopic procedures. However, loads in excess of 200 N may induce significant increases in joint laxity.