ObjectiveTo discuss the effectiveness of operative treatments for different kinds of old injury of extensor tendon in zone II so as to choose the best surgical approach based on the classification of injury. MethodsBetween May 2006 and May 2014, 68 cases of old injury of extensor tendon in zone II were treated. Among them, there were 50 males and 18 females with an average age of 36 years (range, 18-52 years). The causes included contusion injury in 50 cases, avulsion injury in 11 cases, and burn injury in 7 cases. The left side was involved in 21 cases and the right side in 47 cases. The injured finger involved the index finger in 18 cases, the middle finger in 21 cases, the ring finger in 24 cases, and the little finger in 5 cases. The disease duration was 1.5 months to 1 year (mean, 6.75 months). The central slip of extensor was repaired directly in 32 patients who had normal passive motion. Side cross stitch (8 cases) or Littler-Eaton (10 cases) method was used in 18 patients who can not extend actively and passively. Tendon graft was performed in 11 patients with tendon defect. Joint release was given in 7 patients with contracture after burn injury. ResultsPrimary healing of incision was obtained in all cases. Sixty-eight cases were followed up 3-12 months (mean, 6.9 months). Three cases had tendon adhesion in varying degrees and suffered from pain, which was treated conservatively by functional exercise. Recurrence was observed in 2 cases, and extensor tendon was repaired again. According to total active motion (TAM) function assessment, the results were excellent in 52 cases, good in 11 cases, fair in 3 cases, and poor in 2 cases with an excellent and good rate of 92.6%. ConclusionAdaptive operation method for old injury of extensor tendon in zone II should be selected based on the type of injury. The results will be satisfactory if correct method is chosen.
Objective To study the effect of dimethyloxalylglycine (DMOG) on angiogenesis in Choke Ⅱ zone of rats cross-zone perforator flaps and its mechanism. Methods One hundred and twenty-six adult male Sprague Dawley rats were randomly divided into DMOG group, YC-1 group, and control group, with 42 rats in each group. Cross-zone perforator flap model with size of 12 cm×3 cm was made on the back of rats in the three groups. DMOG group was intraperitoneally injected with DMOG (40 mg/kg) at 1 day before operation, 2 hours before operation, and 1, 2, and 3 days after operation; YC-1 group and control group were intraperitoneally injected with YC-1 (10 mg/kg) and the same amount of normal saline at the same time points, respectively. The survival of flap was observed after operation. At 7 days after operation, the survival area of flap in each group was measured and the survival rate of flap was calculated. Flap transmittance test, gelatin-lead oxide angiography, and HE staining were used to observed the angiogenesis in the Choke Ⅱ zone of flaps in each group. Immunohistochemical staining and Western blot were used to detect the expressions of vascular endothelial growth factor (VEGF) and hypoxia-inducible factor 1α (HIF-1α) in Choke Ⅱ zone of flaps in each group. The expressions of VEGF and HIF-1α were also determined by ELISA at 3, 5, and 7 days. Results At 7 days after operation, there was no obvious necrosis at the distal end of the flap in DMOG group, while necrosis occurred in both the control group and YC-1 group, mainly located at the distal end. The flap survival rate of DMOG group was 90.28%±1.37%, which was significantly higher than that of YC-1 group (84.28%±1.45%) and control group (85.83%±1.60%) (P<0.05). DMOG group had more angiogenesis in Choke Ⅱ zone and the vascular structure was clear and complete. In YC-1 group and control group, the vessels in Choke Ⅱ zone was less and the vascular structure was disordered. The number of vessels was (25.56±1.29)/field in the DMOG group, which was significantly higher than that in the YC-1 group [(7.38±0.54)/field] and the control group [(14.48±0.91)/field] (P<0.05). At 3, 5, and 7 days after operation, HIF-1α and VEGF expressions in ChokeⅡzone of DMOG group were significantly higher than those in YC-1 group and control group (P<0.05). ConclusionDMOG can promote angiogenesis in Choke Ⅱ zone, accelerate the early angiogenesis of the flap, improve the microcirculation and blood supply in the potential zone of the flap, reduce the injury of flap ischemia and hypoxia, and increase the survival rate of the flap.