Release and distribution of anti-tuberculosis drug delivery materials locally oriented in the rabbit radius / 中国组织工程研究

BACKGROUND:Polylactic acid-glycolic acid polymer is a sustained-release material with relatively large drug loading and long-term release abilities that can degrade with cel growth in the body. However, its poor hydrophily easily leads to aseptic inflammation that is detrimental to the body’s recovery. OBJECTIVE:To study the release and distribution of anti-tuberculosis drug delivery materials local y oriented within the rabbit radius. METHODS:After modeling, 20 New Zealand white rabbits with distal radius bone defect were randomly divided into a control group and an experimental group, which were respectively given implantation of isoniazid-rifampicin polylactic acid-glycolic acid polymer/β-tricalcium phosphate material and isoniazid-rifampicin polylactic acid-glycolic acid polymer into the defect. Then, X-ray examination of the defect region was conducted at weeks 4, 8, 12 post implantation. Histological observation and detection of peripheral blood or local blood concentration were performed at week 12. RESULTS AND CONCLUSION:After implantation, Lane-Sandhu X-ray scores were significantly higher in the experimental group than the control group (P<0.05). The defect in the experimental group was healed completely with less release residual among newborn bone trabeculae and osteocytes were markedly visible on the material surface, while in the control group, new bone tissues were interconnected with the surrounding bone tissues at the defect site, and less release residual was found. Both peripheral blood and local blood concentrations in the experimental group were significantly higher than those in the control group after implantation (P<0.05). To conclude, the anti-tuberculosis drug delivery material, isoniazid-rifampicin polylactic acid-glycolic acid polymer/β-tricalcium phosphate, has ideal release effect that can stably deliver anti-tuberculosis drugs for a long term at a high bactericidal concentration.

Internal fixation with different bone graftsvia pedicle approach for treatment of thoracic spinal tuberculosis / 中国组织工程研究

BACKGROUND:Lots of bone graft materials such as autologous iliac bone, autologous rib, titanium mesh plus alograft are available in the treatment of bone defects after spinal tuberculosis debridement. OBJECTIVE: To compare the fixation effect of different kinds of bone graft materialsvia pedicle approach fixation for treatment of thoracic spinal tuberculosis. METHODS: Totaly 40 patients with thoracic spinal tuberculosis were enroled, including 18 patients accompanied with paraplegia and 15 patients accompanied with kyphosis deformity. Both of them were subjected to by standard anti-tuberculosis treatment for 2-4 weeks and consequent posterior pedicle screw fixation combined with debridement/bone grafting fusion. They were grouped by the variables of bone graft materials: autologous iliac bone, autologous rib, titanium mesh plus alograft groups. Al patients were folowed up for 24 months. The lesion healing, bone graft fusion, rehabilitation of paraplegia, correction of kyphosis and incidence of adverse reaction were observed. RESULTS AND CONCLUSION: The time of bone graft fusion in the autologous iliac bone group was shorter than that in the autologous rib and titanium mesh plus alograft groups (P < 0.05), and there was no significant difference between autologous rib and titanium mesh plus alograft groups. No adverse phenomenons such as grafts and titanium mesh faling off, fracture and displacement, nonunion and pseudarthrosis, tuberculosis recurrence were found in these three groups. After the symptomatic therapy for 3-6 months, the muscle strength of patients with paraplegia and spinal kyphosis deformity basically recovered, spinal kyphosis deformity was basically corrected. These results demonstrate that the treatment effect of autologous iliac bone is the best; however, the treatment effect of autologous rib is as good as the titanium mesh plus allograft.

Clinical pedicle internal fixation combined with debridement and bone graft through intervertebral approach as treatment of segmental lumbosacral vertebral tuberculosis / 天津医药

Objective To discuss and observe the clinical effect of intervertebral pedicle internal fixation and debride?ment combined with bone graft through posterior approach/trans-intervertebral space approach on the treatment of uni/multi-segmental lumbosacral vertebral tuberculosis (TB). Methods A cohort of 37 patients, with single or multiple segmental ver?tebral destruction due to TB, were treated by trans-intervertebral debridement, posterior pedicle screw system internal fixa?tion and intervertebral bone graft. All patients underwent X-ray,CT and MRI examination to observe the combination treat?ment effect. Results Most patients (n=34) enjoyed primary healing, in which include only 4 cases that presented symptom of nerve root stretch injury during operation but all recovered after 3 months. Other 3 patients underwent secondary healing due to sinus but two were rectifying with anti-TB therapy and wound dressing. The other 1 case suffered from sinus tract was healed through second debridement and rectifying therapy. X-ray, CT and MR at 6 months after operation indicated that all patients present great graft osseous fusion, good recovering of height of vertebral body without kyphosis deformity nor internal fixation loosening nor screw breakage. Conclusion Intervertebral pedicle internal fixation and debridement combined with bone graft through posterior approach/trans-intervertebral space approach is with minimum invasion but good graft fusion ef?fects, harder fixation and satisfactory clinical effects in the treatment of uni/multi-segmental lumbosacral vertebral tuberculosis.