We carried out a prospective study to determine whether the addition of a recombinant human bone morphogenetic protein (rhBMP-2) to a machined allograft spacer would improve the rate of intervertebral body fusion in the spine. We studied 77 patients who were to undergo an interbody fusion with allograft and instrumentation. The first 36 patients received allograft with adjuvant rhBMP-2 (allograft/rhBMP-2 group), and the next 41, allograft and demineralised bone matrix (allograft/demineralised bone matrix group). Each patient was assessed clinically and radiologically both pre-operatively and at each follow-up visit using standard methods. Follow-up continued for two years. Every patient in the allograft/rhBMP-2 group had fused by six months. However, early graft lucency and significant (> 10%) subsidence were seen radiologically in 27 of 55 levels in this group. The mean graft height subsidence was 27% (13% to 42%) for anterior lumbar interbody fusion, 24% (13% to 40%) for transforaminal lumbar interbody fusion, and 53% (40% to 58%) for anterior cervical discectomy and fusion. Those who had undergone fusion using allograft and demineralised bone matrix lost only a mean of 4.6% (0% to 15%) of their graft height. Although a high rate of fusion (100%) was achieved with rhBMP-2, significant subsidence occurred in more than half of the levels (23 of 37) in the lumbar spine and 33% (6 of 18) in the cervical spine. A 98% fusion rate (62 of 63 levels) was achieved without rhBMP-2 and without the associated graft subsidence. Consequently, we no longer use rhBMP-2 with allograft in our practice if the allograft has to provide significant structural support

Aims

Degenerative cervical spondylosis (DCS) is a common musculoskeletal disease that encompasses a wide range of progressive degenerative changes and affects all components of the cervical spine. DCS imposes very large social and economic burdens. However, its genetic basis remains elusive.

We reviewed 15 consecutive patients, 11 women and four men, with a mean age of 48.7 years (37.3 to 62.6), who between July 2004 and August 2007 had undergone percutaneous sacroiliac fusion using hollow modular anchorage screws filled with demineralised bone matrix. Each patient was carefully assessed to exclude other conditions and underwent pre-operative CT and MR scans. The diagnosis of symptomatic sacroiliac disease was confirmed by an injection of local anaesthetic and steroid under image intensifier control. The short form-36 questionnaire and Majeed’s scoring system were used for pre- and post-operative functional evaluation. Post-operative radiological evaluation was performed using plain radiographs. Intra-operative blood loss was minimal and there were no post-operative clinical or radiological complications. The mean follow-up was for 17 months (9 to 39). The mean short form-36 scores improved from 37 (23 to 51) to 80 (67 to 92) for physical function and from 53 (34 to 73) to 86 (70 to 98) for general health (p = 0.037). The mean Majeed’s score improved from 37 (18 to 54) pre-operatively to 79 (63 to 96) post-operatively (p = 0.014). There were 13 good to excellent results. The remaining two patients improved in short form-36 from a mean of 29 (26 to 35) to 48 (44 to 52). Their persistent pain was probably due to concurrent lumbar pathology. We conclude that percutaneous hollow modular anchorage screws are a satisfactory method of achieving sacroiliac fusion

Introduction. Elastic fibres are constructed of a central core of elastin surrounded by microfibrils that are composed mainly of fibrillin-1 and fibrillin-2. Patients with mutations in the gene encoding fibrillin-1 or fibrillin-2 develop Marfan syndrome or Beals syndrome (congenital contractural arachnodactyly), respectively. Scoliosis is one of the clinical manifestations in these patients, but how a defect in the elastic proteins could lead to a spinal deformity is not clear. On the one hand, the mutations could induce scoliosis via mechanical means as they could lead to alterations in the biomechanics of the elastic fibre system. On the other hand, elastic fibres also bind growth factors such as transforming growth factor β (TGFβ) and bone morphogenic proteins (BMPs), and the mutations could hence change patterns of spinal growth. Methods. We have investigated the localisation of elastic proteins in different spinal tissues at different stages of curve development in mouse models and in human tissue obtained during scoliosis surgery. Results. Elastic proteins were observed not only in the spinal connective tissues such as ligaments and intervertebral discs, but also in muscle and the bone matrix. The distribution of the different elastic proteins was tissue specific. Additionally, elastic proteins were also detected in the matrix of the vertebral-body growth plates (figure), which has not been reported previously. Conclusions. These observations suggest that elastic proteins could have several functions in the spinal column. Their presence and organisation in the growth plate suggests that they could play an important part in orchestration of spinal growth; a fibrillin mutation-induced malfunction in this regard could be a factor in the development of scoliosis

A literature review of bone graft substitutes for spinal fusion was undertaken from peer reviewed journals to form a basis for guidelines on their clinical use. A PubMed search of peer reviewed journals between Jan 1960 and Dec 2009 for clinical trials of bone graft substitutes in spinal fusion was performed. Emphasis was placed on RCTs. Small and duplicated RCTs were excluded. If no RCTs were available the next best clinical evidence was assessed. Data were extracted for fusion rates and complications. Of 929 potential spinal fusion studies, 7 RCTs met the inclusion criteria for BMP-2, 3 for BMP-7, 2 for Tricalcium Phosphate and 1 for Tricalcium Phosphate/Hydroxyapatite (TCP/HA). No clinical RCTs were found for Demineralised Bone Matrix (DBM), Calcium Sulphate or Calcium Silicate. There is strong evidence that BMP-2 with TCP/HA achieves similar or higher spinal fusion rates than autograft alone. BMP-7 achieved similar results to autograft. 3 RCTs support the use of TCP or TCP/HA and autograft as a graft extender with similar results to autograft alone. The best clinical evidence to support the use of DBMs are case control studies. The osteoinductive potential of DBM appears to be very low however. There are no clinical studies to support the use of Calcium Silicate. The current literature supports the use of BMP-2 with HA/TCP as a graft substitute. TCP or HA/TCP with Autograft is supported as a graft extender. There is not enough clinical evidence to support other bone graft substitutes. This study did not require ethics approval and no financial support was received

To determine the current practice of scoliosis surgery in the UK. A 10 point questionnaire was constructed to identify the philosophy of surgeons on various aspects of scoliosis surgery such as choice of implant, bone graft, autologous blood transfusion (ABT), cord monitoring and computer assisted surgery. Results are compared with the current best evidence. Consultants and Fellows attending the 2009 British Scoliosis Society meeting. 50 questionnaires were completed: 45 Consultants and 5 Fellows. All pedicle screw construct favored by 25/50, hybrid 24/50 (one undecided). Posterior construct of less than 10 levels, 20/50 would not cross-link, 11/50 used one and 19/20 used two or more. More than ten levels 17/50 considered cross-links unnecessary, 4/50 used one and 29/50 used two or more. 88% preferred titanium alloy implants, while a mixture of stainless steel and cobalt chrome was used by others. For bone graft, substitutes (24), iliac crest (14), allograft (12) and demineralised bone matrix (9) in addition to local bone. 10/50 would use recombinant bone morphogenetic protein (3 for revision cases only). 39/50 routinely used intra-operative cell salvage or ABT drains and 4/50 never used autologous blood. All used cord monitoring, Sensory (19/50), Motor (2/50) and combined (29/50). None used computer-aided surgery. 26 operated alone 12 operated in pairs and 12 varied depending on type of case. This survey has brought to light interesting variations in scoliosis surgery in UK. It may reflect the conflicting evidence in the literature

Background. For bone grafting procedures, the use of autologous bone is considered the gold standard, as it is has a better healing capacity compared to other alternatives as allograft and synthetic bone substitutes. However, as there are several drawbacks related to autografting (infection, nerve- or vascular damage, chronic pain problems, abdominal herniation), there has been a targeted effort to improve the healing capacities of synthetic bone substitutes. Aim. To evaluate the performance of a carbonated osteoionductive hydroxyapatite (CHA) scaffold of clinical relevant size (Ø=15mm, H=50mm) in a sheep model of multi level posterolateral intertransverse lumbar spine fusion after activation with autologous bone marrow nuclear cells (BMNC) in a flow perfusion bioreactor. Method. Two groups were included in the study, autograft (n=6) and CHA scaffold (n=6) CHA. A paired design was used between and within the groups as lumbar posterolateral arthrodesis was performed in sheep on two levels (L2-L3, L5-L6) +/− BMNC, respectively. Before implantation, the CHA scaffold was cultured in a flow perfusion bioreactor system with BMNC for 21 days, and the autograft group was supplemented with isolated BMNC during the procedure. Micro tomography was used to evaluate fusion rate and the microarchitectural properties of the explants after an observation period of four months. Results. In the autograft group, the healing rate was 83.3% irrespective of the presence BMNC, and in the CHA group, 66.7% fused in the presence of BMNC, and 33.3% without. The microarchitectural data suggested the autograft group to be superior to the CHA scaffold regarding mechanical properties, however porosity decreased significantly (p=0.001) in the CHA scaffold group suggesting deposition of mineralized bone matrix. Conclusion. Based on the fusion rate and micro architectural properties, we consider the CHA scaffold fully capable of new bone formation, and that the presence of BMNC has a positive effect on the fusion rate in a challenging model of bone healing

Objectives

We performed a systematic review of the literature to determine the safety and efficacy of bone morphogenetic protein (BMP) compared with bone graft when used specifically for revision spinal fusion surgery secondary to pseudarthrosis.