Experimental study of prognosis of chronic compartment syndrome.

There is little in the literature concerning the pathobiology and repair processes of impaired skeletal muscle after decompressive operation for chronic compartment syndrome (CCS), which would be valuable for prognosis. Repeated tourniquet compression through cuff inflation on rabbits' claves was performed daily for 2 hr, then stopped for 30 min, and applied for another 2 hr. The contralateral hindlimb, which was not compressed, served as a control. Rabbits were allocated to four groups: groups I and II were pressured with 80 and 120 mmHg for 3 days, and groups III and IV were pressured with 80 and 120 mmHg for 14 days. Skeletal muscle specimens from each group were obtained for histological and ultrastructural observation at day 1, 7, 14, and 28 post-compression. In groups I and II, a few necrotic fibers were observed and basal lamina was intact at 1 day after compression. Seven days after compression, there was an observable increase in the proliferation of satellite cells and development of myotube structures. Fourteen days after compression, regeneration of muscles was complete, and there was no significant difference compared with the control group. In groups III and IV, 1 day post-compression examination revealed a large area of necrotic fibers, fibrotic interstitium, and disintegratin basal lamina. Seven days later, proliferation of satellite cells was observed around the surviving basal lamina, and 28 days after compression we could see a large area of fibrosis. The degree of recovery of impaired muscle in rabbit's CCS-induced tissues is related to pressure and duration of compression. Complete recovery of the impaired muscle is determined by survival of basal lamina.