TUBERCULOUS KYPHOSIS — EVOLVING CONCEPTS IN PREVENTION AND TREATMENT

In spinal tuberculosis, children bone is easily destroyed, and as a result spinal deformity complicates in higher rates in comparison with the adult tuberculous spine. However, the pediatric spine with tuberculosis is more flexible than those of the adult-spine, because spontaneous intercorporal fusion of the diseased segments in children never occur. Thus, prevention and/or correction of the tuberculous kyphosis is easier than those of the adults. Also in particular by posterior tethering instrumentation surgery the formed kyphosis can be corrected gradually during growth period. The key message is that in pediatric spinal tuberculosis, spontaneous intercorporal fusion of the diseased segment hardly takes place even under the posterior instrument-aided stabilization and the coverage of antituberculous chemotherapy. Therefore, tuberculous spine in children even after cure should be observed until growth maturity.

In VivoandIn VitroStudy of a Polylactide-Fiber-Reinforcedβ-Tricalcium Phosphate Composite Cage in an Ovine Anterior Cervical Intercorporal Fusion Model

A poly-70L/30DL-lactide (PLA70)–β-tricalcium phosphate (β-TCP) composite implant reinforced by continuous PLA-96L/4D-lactide (PLA96) fibers was designed forin vivospinal fusion. The pilot study was performed with four sheep, using titanium cage implants as controls. The composite implants failed to direct bone growth as desired, whereas the bone contact and the proper integration were evident with controls 6 months after implantation. Therefore, the PLA70/β-TCP composite matrix material was further analyzed in thein vitroexperiment by human and ovine adipose stem cells (hASCs and oASCs). The composites proved to be biocompatible as confirmed by live/dead assay. The proliferation rate of oASCs was higher than that of hASCs at all times during the 28 d culture period. Furthermore, the composites had only a minor osteogenic effect on oASCs, whereas the hASC osteogenesis on PLA70/β-TCP composites was evident. In conclusion, the composite implant material can be applied with hASCs for tissue engineering but not be evaluatedin vivowith sheep.

A Technical Modification of Cloward's Posterior Lumbar Interbody Fusion

The concept of interbody (intercorporal) fusion as a useful treatment for intervertebral disc disease in the cervical area has been well received. Thirty-two years have passed since Cloward first introduced his technique of posterior lumbar intervertebral fusion. The author believes that the delayed acceptance of this procedure is due to fear of technical difficulties. A technical modification of Cloward's posterior lumbar interbody fusion is introduced. It entails better technique in controlling epidural bleeding by careful positioning of the patient and the use of oxidized cellulose as a tampon in the epidural space. The integrity of the facet is preserved through a more limited interlaminal approach. Osteosynthesis of the grafts is assured by multiple perforations of the cortical plate in accordance with Robinson's principle utilized in cervical interbody fusion. The author believes that the modification simplifies the Cloward posterior lumbar interbody fusion. It also assures better stability after surgery by retention of the facet and lessening the dangers of settlement of the graft by preservation of the cortical plate. In a series of 75 cases, tomograms made 4 months after operation have shown a viable graft with active osteosynthesis between the graft and the adjoining vertebral bodies in 94%.