Experimental and clinical evaluation of an absorbable biomaterial inducing an anti-adhesive barrier (Divide®)

Abstract

We evaluated the efficacy of a biomaterial composed of oxidised regenerated cellulose (Divide) in decreasing the formation of peri-tendinous adhesions in an experimental and clinical study. The experimental study was carried out in 47 New Zealand white rabbits whose Achilles tendons were subjected to a crush injury. The left Achilles tendon served as a control, while the right tendon was wrapped in a sheet of Divide®. Six weeks later the range of motion at the ankle was measured, the tendons were histologically analysed for peri-tendinous adhesions, the tendon sheath was examined using a scanning electron microscope for determining resorption of the biomaterial and the mechanical properties evaluated. The clinical study was performed on 22 patients; 16 requiring post-traumatic extensor tenolysis and six who underwent dorsal synovectomy for rheumatoid arthritis. A sheet of Divide® was placed either between the periosteum and the tendon or around the tendon in all patients. Total active motion and grip strength was evaluated in all patients pre-operatively and at regular intervals post-operatively. The experimental study showed that ankle range of motion was similar between the control and Divide® treated groups in two rabbits, better in the Divide® group in seven rabbits and better in the control group in two rabbits. The results were not statistically significant (P ≤ 0.262) since the numbers were quite low. Histological analysis showed that the treated tendon had a better gliding surface and minimal inflammation/reaction compared to the control group. Scanning electron microscopy on the 10th post-operative day revealed the formation of a new tendon sheath in the Divide® group. The mechanical properties of both the control and experimental Achilles tendon were similar and comparable to a human tendon. The clinical study demonstrated that Divide® was completely resorbed, perfectly biocompatible and non-allergenic. The mean T.A.M. improved from 159.4° to 187.3° (P ≤ 0.074) and grip strength from -26.7 kgF to 10.7 kgF on the 84th post-op day in the extensor tenolysis group (16 digits), while mean return of function to pre-operation level was achieved at 42nd post-operative day and grip strength increased from -3.4 kgF in the immediate, post-operative period to +5.7 kgF at the 84th day in the rheumatoid arthritis group. © 2008 The Author(s).