Operative treatment for separation of distal tibiofibular syndesmosis.

OBJECTIVE: To study the influence of separation of distal tibiofibular syndesmosis on ankle joint and to compare various operative methods so as to find suitable stabilization for separated distal tibiofibular syndesmosis. METHODS: From July 1997 to July 2002, we treated 87 patients (64 males and 23 females, aged 18-54 years) with separation of distal tibiofibular syndesmosis, among whom, 79 were combined with fracture of malleolus. Manipulative reduction, internal fixation with cancellous screws and external fixation with plaster support were performed on 37 patients, fixation with plate and screws for fibular fracture and fixation with cancellous screws for distal tibiofibular syndesmosis on 34 patients, and repair of the distal tibiofibular ligaments with tendon of peroneus longus, reduction of the separated distal tibiofibular syndesmosis, and fixation with cancellous screws on 16 patients. The ankle joint had been dorsiflexed for 30 degrees when the distal tibiofibular syndesmosis was fixed with cancellous screws. And the cancellous screws were taken out at 8-10 weeks after operation. RESULTS: These patients were followed up for at least two years. The curative effects were assessed according to the complaints of the patients and the contour, function and radiogram of the ankle joint: excellent in 55 patients (63%), good in 18 patients (21%), and fair in 14 patients (16%). Separation of distal tibiofibular syndesmosis recurred in 2 patients, who underwent a reoperation for repairing the distal tibiofibular ligaments with tendon of peroneus longus and recovered. One cancellous screw was broken off. No necrosis developed in the anterior skin of the ankle mortise. CONCLUSIONS: Separation of distal tibiofibular syndesmosis can be treated with various reasonable operations. Repair with tendon of the peroneus longus can get excellent outcomes for complete separation of the distal tibiofibular syndesmosis.

[Experimental study on the prevention of epidural scar adhesion with polycaprolactone/polylactic acid membrane].

OBJECTIVE: To evaluate the ability of a polycaprolactone/polylactic acid (PCL/PLA) membrane to inhibit epidural scar adhesion after laminectomy, and observe the responsive changes of the pain media in the spinal cord. METHODS: L(1), L(3) laminectomies were performed on 96 Wistar rats. The rats were divided into 3 groups: None-implant Control Group (NC), Autologous free fat graft group (AFFG) and PCL/PLA membrane group (PCL/PLAm). The rats were killed at 1, 3, 6, and 12 weeks postoperatively. Epidural scar formation and adhesion were observed grossly and histologically. Reverse transcription polymerase chain reaction (RT-PCR) were used to analyses the expression of Transforming growth factor beta (TGF-beta) in the epidural scar. Immunohistochemistry stain and RT-PCR were performed to evaluate the expression of the substance P and the c-fos gene in the relevant spinal cord, and the results were analyzed statistically. RESULTS: Gross evaluation and histological evaluation showed that in the NC lamina defect site had much scar tissue and had wide and tight adhesions to the dura; in the AFFG, with the fat degrading gradually, the adhesions were increased; whereas in the PCL/PLAm group, there were slightly adhesions to the dura. RT-PCR showed that the expression of the TGF-beta was much less in the PCL/PLAm group than in the NC group. The insertion of the PCL/PLA membrane and the fat patch reduced the expression of the substance P and the c-fos gene in the spinal cord. CONCLUSION: The insertion of the PCL/PLA membrane reduces scar formation and separates fibrosis tissue from the dura, the results indicate that PCL/PLA membrane is an effective way of reducing peridural scar formation and preventing the failed back surgery syndrome.