It is important to assess spinal injuries, both in terms of cord damage and column damage, shortly after the trauma has occurred. A decision should then be made concerning the eventual stability of the bony vertebral column. If a lesion is unlikely to heal soundly by bone or if one is unable to obtain a reduction by conservative measures, one should consider surgical stabilisation of the damaged spine in the subacute phase. At the same time as one stabilISES THe spine with metallic fixation, bone grafts should be added for ultimate stability. If an unstable spine is encountered in the later stages of treatment, surgical stabilisation is again indicated. Metallic fixation can greatly aid in stabilising the spine until bone grafts can mature. Osteotomies of the spine through a combined transthoracic and posterior approach can be extremely valuable in correcting deformity. While there is no role for decompressive surgery after spinal cord injury, there is still a definite role for surgery in balancing and stabilising the vertebral column. (+info)
The cellular changes during osteogenesis in bone and bone marrow composite autografts.
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Osteogenesis in and around autografts has been studied in the hope of identifying the osteoblast precursor. Fresh autografts of cortical bone with its constituent bone marrow were implanted into intramuscular sites in rats. The grafts were removed at intervals over a four week period and examined by light and electron microscopy. A chronological sequence of degenerative, reparative and differentiative events was found and described. The relative contributions of the host and graft components to post-grafting osteogenesis are discussed and the problem of the origin of the osteoblast cells is examined, taking into account present views about the interrelationships between skeletal connective tissue cells and their precursors. It is concluded that, in the investigation described, the presence of host granulation tissue was necessary for osteogenesis and it is postulated that osteoblast progenitor cells can arise from this granulation tissue, their differentiation along the osteogenic line being stimulated in some way by the presence of the graft bone. (+info)
Intraosseous neurilemmoma of the cervical spine causing paraparesis and treated by resection and grafting.
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A neurilemmoma presented as an expanding lesion of the bodies of C6 and C7 vertebrae and caused local neurological signs together with a spastic paraparesis. This tumour was treated by preliminary posterior fusion, followed by its complete removal via an anterior approach and stabilization by anterior spinal fusion. Other cases in the literature are reviewed and discussed. (+info)
Bone marrow-derived antigen-presenting cells are required for the generation of cytotoxic T lymphocyte responses to viruses and use transporter associated with antigen presentation (TAP)-dependent and -independent pathways of antigen presentation.
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Bone marrow (BM)-derived professional antigen-presenting cells (pAPCs) are required for the generation of cytotoxic T lymphocyte (CTL) responses to vaccinia virus and poliovirus. Furthermore, these BM-derived pAPCs require a functional transporter associated with antigen presentation (TAP). In this report we analyze the requirements for BM-derived pAPCs and TAP in the initiation of CTL responses to lymphocytic choriomeningitis virus (LCMV) and influenza virus (Flu). Our results indicate a requirement for BM-derived pAPCs for the CTL responses to these viruses. However, we found that the generation of CTLs to one LCMV epitope (LCMV nucleoprotein 396-404) was dependent on BM-derived pAPCs but, surprisingly, TAP independent. The study of the CTL response to Flu confirmed the existence of this BM-derived pAPC-dependent/TAP-independent CTL response and indicated that the TAP-independent pathway is approximately 10-300-fold less efficient than the TAP-dependent pathway. (+info)
Osteoarticular allograft in surgery for high-grade malignant tumours of bone.
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We assessed the results of 17 limb-salvage procedures using osteoarticular allografts after wide resection of high-grade malignant bone tumours. All patients received chemotherapy. At the five-year follow-up, three patients had died from metastases. The allografts survived for five years in only seven patients all of whom had good function, ranging from 73% to 90% of normal. The allografts were removed because of fracture in seven patients and infection in one, and in all of these a second limb-salvage procedure was undertaken. With such a low rate of survival of osteoarticular allografts, we believe that their use in the management of high-grade malignant bone tumours should, at best, be considered a temporary solution. (+info)
Vascularised fibular grafts. An experience of 102 patients.
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The results and complications of 104 vascularised fibular grafts in 102 patients are presented. Bony union was ultimately achieved in 97 patients, with primary union in 84 (84%). The mean time to union was 15.5 weeks (8 to 40). In 13 patients, primary union was achieved at one end of the fibula and secondary union at the other end. In these patients, the mean time to union was 31.1 weeks (24 to 40). Five patients failed to achieve union, with a resultant pseudarthrosis (3 patients) or amputation (2 patients). There were various complications. Immediate thrombosis occurred in 14 cases. In two of 23 patients with osteomyelitis, infection recurred at two and six months after surgery, respectively. Both patients had active osteomyelitis less than one month before the operation. Bony infection occurred in a patient with a synovial sarcoma of the forearm one year after surgery. In 15 patients, 19 fractures of the fibular graft occurred after bony union, all except one within one year after union. In patients in whom an external fixator had been used, fracture occurred soon after its removal. Union was difficult to achieve in cases of congenital pseudarthrosis of the tibia. Appropriate alignment of the fibular graft is an important factor in preventing stress fracture. The vascularised fibula should be protected during the first year after union. Postoperative complications at the donor site included transient palsy of the superficial peroneal nerve in three patients, contracture of flexor hallucis longus in two and valgus deformity of the ankle in three. Vascularised fibular grafts are useful in the reconstruction of massive bony defects. We believe that meticulous preoperative planning, including choosing which vessels to select in the recipient and the type of fixation devices to use, and care in the introduction of the vascularised fibula, can improve the results and prevent complications. (+info)
The influence of avascularity on the mechanical properties of human bone-patellar-tendon-bone grafts.
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Our aim was to analyse the effect of avascularity on the morphology and mechanical properties (tensile strength, viscoelasticity) of human bone-patellar-tendon-bone (BPTB) grafts in vitro. These were harvested at postmortem and stored submerged in denaturated human plasma at a constant pH, pO2, pCO2, temperature and humidity under sterile conditions. Mechanical testing was performed two and four weeks after removal of the graft. The mean ultimate strength was 1085.7 +/- 255.8 N (control), 1009.0 +/- 314.9 N (two weeks cultured) and 1076.8 +/- 414.8 N (four weeks cultured). There was no significant difference in linear stiffness or deformation to failure between the groups. There was a difference in viscoelasticity between the control group and the avascular grafts and the latter had significant lower peak load-to-load ratios after 15 minutes compared with the control group. After two and four weeks the graft contained viable fibroblasts. There was regular cellularity in the superficial layers and decreased cellularity in the midportion. The structure of the collagen including the crimp pattern appeared to be normal in polarised light. We conclude that avascularity does not significantly affect ultimate failure loads or stiffness of BPTB grafts. Slight changes in viscoelasticity were induced, but the significance of the increased stress relaxation is not fully understood. (+info)
An x-ray study of valgus ankles in spina bifida children with valgus flat foot deformity.
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Radiological examination of the ankles of spina bifida children with flail lower limbs and valgus flat foot deformity has revealed a high incidence of abnormal valgus tilt of the ankle-joint. A study of ankle X-rays of spina bifida children before and after extra-articular subtalar fusion in which the bone graft is removed from the ipsilateral tibia has shown that the valgus tilt of the mortice may increase after this procedure. (+info)