Continuous passive motion after knee-joint arthrolysis under catheter peridural anesthesia.

The results of arthrolysis of a stiff knee are often poor because postoperative pain prevents the early active mobilization that is so essential. Adequate analgesia may be ensured by the use of continuous anesthesia via a peridural catheter; in combination with continuous passive motion, such analgesia is able to maintain, and often improve, the range of movement obtained at surgery. Twenty-two patients treated in this way showed improvement in the range of movement between 39 degrees and 120 degrees. Patients with post-traumatic knee stiffness achieved an average improvement in the range of movement of 93%, while those with stiffness following infection improved by only 55% on the average. The preoperative loss of movement does not appear to determine the end result; the etiology of the stiffness is more important.