To date, the goals of spinal surgery have been easy to define: to ‘decompress’, to ‘realign’ and to ‘fuse’. More recent refinements have been directed towards two new goals: to ‘preserve’ and to ‘protect’.

Preservation of the enveloping soft tissues minimises bleeding and scarring, and reduces pain. This can be facilitated by minimal and alternate access surgery, using techniques such as percutaneous pedicle screw insertion, transpsoas and transsacral vertebral access and endoscopic scoliosis correction. Protection of the neural elements improves the safety of spinal surgery and allows the surgeon to perform more complex procedures. Methods have been developed to accurately guide the surgeon to the target structure or pathology while avoiding neural structures, and to monitor spinal cord and nerve function. Both approaches allow safer instrumentation and deformity correction.

In the past, protection of important structures has been achieved by wide exposures, sacrificing preservation of soft tissues. As this shortcoming has been recognised, techniques have been developed that have radically reduced wound size but often compromised vision and put neurovascular elements at risk. Refinements have attempted to balance these goals. At present, we have a variety of techniques available to us but were hare hampered by cost and complexity. The future will hopefully bring further improvements but perhaps new ideas and approaches that challenge our current concepts of invasive spinal surgery.

Introduction: Bone morphogenetic protein (BMP) has become widely used in the interbody space as part of a lumbar fusion. Complications can occur but are not completely understood or well documented.

Methods: A prospective review of consecutive lumbar interbody fusions performed by a single surgeon was undertaken over a 2-year period. Early complications (defined as occurring within the first six weeks) were noted. The interbody cages (titanium Syncage, Synthes cages for ALIFs and PEEK Capstone, Medtronic cages for TLIFs) were filled with Infuse BMP-collagen sponge. Until early 2007, the amount of Infuse used was not strictly measured but after that time, only enough to fill the cage was used, with the volume assessed according to the manufacturer’s guidelines. Patients were routinely assessed preoperatively and at the six-week postoperative review using a visual analogue scale and the Oswestry disability score. Plain x-ray and MRI were obtained preoperatively, and plain x-ray was obtained postoperatively. In addition, if early problems developed, MRI scan was obtained. The incidence of complications was compared to that seen in similar procedures but where BMP was not used.

Results: 114 patients, including 78 transforaminal inter-body fusions (TLIFs) and 36 anterior lumbar interbody fusions (ALIFs) were available for review. Early complications were noted in 10 of 114 patients. Two (both with TLIF) were not directly linked with BMP use: in the first, the cage migrated posteriorly and in the second, a deep infection developed. The remaining eight were associated with an exaggerated inflammatory response likely related to BMP use. Severe back pain associated with marked vertebral body inflammation seen on MRI was noted in two ALIF patients. The response occurred within 2 weeks of surgery, and settled with conservative treatment. Severe back pain and recurrence of leg pain developed in six TLIF patients. Fluid cyst formation within the spinal canal was seen on MRI in 4 of these. The cyst extended from the region of the posterior aspect of the cage into the canal and toward the area of the excised facet joint, resulting in compression of the exiting nerve root. In one case, the surgical site was re-explored and the cyst removed. In two cases, the cyst was aspirated under CT guidance and injected with steroid. In the final case a course of oral Prednisone was administered. In the remaining two TLIF cases, there was a diffuse inflammatory response in the region of the posterior aspect of the cage and adjacent epidural space but without discrete cyst formation. In one, oral Prednisone was prescribed. The second was treated expectantly. The majority of these complications were noted in 2007, after the dose of BMP was titrated in line with the manufacturer’s guidelines. In contrast, no such complications were seen when a similar technique but without BMP was undertaken in 33 posterior and 41 anterior interbody fusions.

Discussion: The incidence of an exaggerated inflammatory response with BMP in the lumbar spine may be under-recognised. The majority of complications published to date relate to vertebral osteolysis and bony overgrowth, although a number of adverse responses to BMP reported to the FDA relate to fluid cyst formation or inflammation. With the rapid increase in BMP use, it is important that surgeons are aware of potential complications, and possible strategies to prevent and address them.

Introduction: Prosthetic Disc surgery is a rapidly growing field in patients with symptomatic degenerative disc disease. Few reports of long-term follow up are yet published, but several authors have published case series including reports of significant complications and difficulties with revision surgery¹. Advocates of disc replacement surgery have claimed that Osteolysis, whilst being a potential problem associated with artificial disc replacement, has not yet been reported².

Methods: We present what we believe is the first histologically proven case of significant Osteolysis associated with artificial disc replacement in the world literature. We also present a literature review of the laboratory research into performance of artificial disc replacement, focusing on wear debris and particle generation.

Results: Our report involves a 42-year-old lady with degenerative disc disease who underwent L5/S1 anterior lumbar interbody fusion in July 1999, with a simultaneous L4/L5 Charite disc prosthesis. In May of 2002 she developed significant back pain, and further investigation, including biopsy revealed polymer disintegration and associated Osteolysis. Attempted revision surgery in May 2003, using a combined anterior approach by a vascular and spinal surgeon, led to damage to the adherent common iliac vessels and inferior vena cava, and the attempt to remove the prosthesis was abandoned. Histological samples taken at surgery confirmed the presence of polyethylene wear debris. Posterior instrumented fusion was performed in June 2003 and the patient made a successful recovery.

Discussion: It is important in modern spinal practice to be fully aware of both reported and potential risks of the use of new prostheses. We report an important complication associated with the use of artificial disc replacement. Revision of such prostheses is challenging, and we advise a combined surgical approach.

Introduction Charcot arthropathy is a well recognised complication in denervated synovial joints. This is a late complication of traumatic spinal cord injury that is rarely reported in the literature. Early recognition is important and can be difficult as the clinical presentation can vary from pain, deformity, autonomic dysreflexia and audible noises with motion.

Methods We present 5 cases of Charcot’s arthropathy of the spine in patients with in patients with traumatic paraplegia. All patients had spinal surgery to stabilise the spine shortly after the acute injury.

Results The average time from initial injury to presentation with Charcot’s arthropathy was 27 years (range 10–41). A combination of localised and neuropathic pain was the dominant symptom (4 patients) causing re-presentation, but other symptoms included deformity (1 patient). The level of the initial spinal cord injury was at the thoracolumbar junction patients. The Charcot joint level was usually 1 to 2 segments caudal to the spinal fusion. The features noted on plain radiology were destructive changes of the endplate in 4 patients and deformity in 1. With one exception, all patients went on to have MRI to exclude infection and subsequently all were surgically stabilised. All patients were treated surgically. One had an anterior approach, one had posterior approach and one had staged anterior and posterior approaches. The remaining two had anterior and posterior stabilisation through a lateral extra-cavitary approach.

At an average follow-up of 36 months all patients reported good relief of their symptoms, and had returned to their best function post-injury.

Discussion Surgical stabilisation in this series yielded very good results. We observed a wide variation in presenting symptoms and therefore would indicate that a high index of suspicion is required. We believe that MRI is mandatory to exclude infection and would advocate early stabilisation. The lateral extra-cavitary approach allows posterior and anterior stabilisation in a single procedure and in now the preferred method in our institution. As patients with spinal cord injuries live increasingly active lives, this problem will be seen more frequently.

Introduction The devastating and permanent effects of complete spinal cord injury are well documented. In animal models, olfactory ensheathing cells (OEC) transplanted into areas of complete spinal cord injury have promoted regeneration of the neural elements with reconnection of the descending motor pathways. This reproducible anatomical finding is associated with significant motor functional recovery. Accordingly, cellular transplantation therapies have been advocated for human spinal cord injury.

In a single-blind, Phase I clinical trial, we aimed to test the feasibility and safety of transplantation of autologous olfactory ensheathing cells into the spinal cord of three humans with complete spinal cord injury. This paper describes the trial and the surgical procedures and presents twelve month safety data.

Methods Six patients with paraplegia resulting from chronic (6 – 36 months post-injury) traumatic spinal cord injury (thoracic) were enrolled in the trial. Exclusion criteria included the presence of vertebral column instability, syringomyelia, an implanted spinal device or instrumentation and the presence of psychological instability. The patients were allocated to a treatment group and a control group. No intervention was undertaken to the control group.

Olfactory ensheathing cells were harvested from each subject in the surgery group, grown and purified in vitro. After exposure via laminectomy, durotomy and adhesolysis, the cells were injected into the region of injured spinal cord.

All patients are tested on enrollment and then at regular intervals up to three years by a group of assessors who are blinded to the treatment or control group status. These assessments include physical, radiological, neurophysiological and psychosocial parameters.

Results All surgery patients exhibited continuity of presumed pia through the cystic region at the site of injury. The spinal cord adjacent to the cyst appeared macroscopically normal. There were no complications of surgery evident in the peri-operative period. At twelve months there was no evidence of tumour formation, syrinx development, clinical or psychosocial deterioration.

Discussion The dictum, primum non nocere, is especially relevant to the emerging field of human spinal cord regeneration. Animal models promise such exciting potentials for therapy in this devastating condition, that the possibilities need to be fully explored. Anecdotal, non-trial based reports suggest that equivalent results may be able to be obtained in humans. However, science and care should guide the endeavours in this controversial field.

This is the first reported trial of OEC’s in human spinal cord injury. Twelve-month data in a small cohort shows that there is no evidence of adverse events that would preclude completion of the current trial and the development of efficacy trials.

Introduction Locking plates are the most used devices for achieving anterior cervical spinal fusion and offer considerable advantages such as faster and easier implantation and fewer implant-related failures than older plate systems. Recently polyaxial locking screws were introduced to make the implantation of these plates even easier by facilitating the implantation of the screw in all directions. However polyaxial screws may have the disadvantage of losing the angular stability with subsequent failure of the plate. The aim of this study was the radiological follow up of the patients with polyaxial screw and to compare them with the conventional looking plates.

Methods Patients underwent anterior cervical discectomy and fusion in which either ventral cervical locking plates or a polyaxial locking screw were used for indications including cervical spondylotic radiculopathy, disc herniation, trauma, and myelopathy. Patients underwent anterior cervical discectomy and interbody fusion and / or corpectomy. Preoperative and postoperative radiographic data included sagittal angle, translation, and settling of the graft.

Results One hundred and forty patients were investigated (mean age of 49 years) with an average follow up period of 21.5 months (range from 4 to 50 months). All underwent anterior cervical plate fusion as a component of the surgical treatment for symptomatic degenerative cervical spinal disease (55%) or for vertebral destruction caused by trauma (45%).100 (71%) of patients were treated with a conventional locking plate and 29 % with a plate with polyaxial screw fixation. Besides plate fixation, 4 of the 140 patients had a combined ventrodorsal fusion. In 46 cases (25%), one or more vertebral bodies were removed and replaced with either iliac bone graft (two levels, 21% of all cases) or fibula strutgraft (4%). In the group with conventional locking plates no patient had to be revised, 3 showed a subluxation (up to 1/3 of the vertebral body diameter) and 2 screw back out posteriorly without clinical relevance. In the group with the plate with polyaxial screw fixation two patient had to be revised (posterior stabilisation) because of subluxation due to loss of angular stability of the screws and one patient developed subluxation of 1/3 of the vertebral body also due to loss of angular stability.

Discussion The complication rate and the revision rate for anterior cervical discectomy and fusion with plates with and without polyaxial screw fixation were similarly low. Polyaxial screw may have the theoretical disadvantage of loosening with loss of the angular stability and subsequent failure necessitating revision.

Introduction: Anterior lumbar interbody fusion (ALIF) with posterior stabilisation is an established treatment for degenerative disc disease.¹ Some previous reports have advocated a goal of 360 degree fusion, and condemned posterior stabilisation as it does not achieve fusion of the posterior facet joints.² Others have claimed that the concept of a ‘locked pseudarthrosis’ gives satisfactory clinical results.³ There is also a contention that private or self-funding patients achieve better results after spinal fusion compared to those treated under compensation or Dept. Veterans Affairs (DVA) schemes.

Methods: Twenty patients who had undergone an ALIF with posterior stabilisation were retrospectively reviewed. All had a follow-up greater than 12 months. 13 patients were private and 7 non-private. The groups were aged and sex matched. Radiological assessment of fusion was made with reconstruction CT scans. Oswestry Disability Index (ODI) scores were recorded preoperatively, 6 months and 12 months post operation.

Results: Patients with locked pseudarthrosis showed no significant difference in outcome compared to those with radiological fusion. Both groups showed signifi cant improvement in ODI scores after ALIF (mean preop. = 52 – range 16-74; mean postop. = 18 – range 0-52; p< 0.01). There was a significantly greater improvement (p< 0.02) in ODI scores in private patients (mean reduction = 41 points) compared to worker’s compensation or DVA patients (mean reduction = 22 points).

Discussion: The results indicate that ALIF with posterior stabilisation can achieve good clinical results even with a ‘locked pseudarthrosis’. While there is no significant difference between outcomes in different health funding groups shown in the study, carefully patient select for this treatment is the key to success.

Introduction: Prosthetic disc surgery is a rapidly growing field in patients with symptomatic degenerative disc disease. Few reports of long-term follow up are yet published, but several authors have published case series including a report of significant complications and difficulties with revision surgery¹. Advocates of disc replacement surgery have claimed that osteolysis, whilst being a potential problem associated with artificial disc replacement, has not yet been reported.

Methods: The literature relating to the laboratory research into performance of artificial disc replacement, focusing on wear debris and particle generation is reviewed. Reports of complications are reviewed. A case of significant osteolysis associated with artificial disc replacement is reported.

Results: Our report involves a 42-year-old lady with degenerative disc disease who underwent L5/S1 anterior lumbar interbody fusion in July 1999, with a simultaneous L4/L5 Charité disc prosthesis. In May of 2002 she developed significant back pain, and further investigation revealed polymer disintegration and associated osteolysis. Attempted revision surgery in May 2003, using a combined anterior approach by a vascular and spinal surgeon, led to damage to the adherent common iliac vessels and inferior vena cava, and the attempt to remove the prosthesis was abandoned. Histological samples taken at surgery confirmed the presence of polyethylene wear debris. Posterior instrumented fusion was performed in June 2003 and the patient made a successful recovery.

Discussion: It is important in modern spinal practice to be fully aware of both reported and potential risks of the use of new prostheses. Wear of an artificial disc causing osteolysis is anticipated. This is believed to be the first case in the world literature of this important complication associated with the use of artificial disc replacement. Revision of disc prostheses with osteoly-sis is challenging, and a combined surgical approach is advised.

Introduction: Sports injuries to the cervical spine account for about one in ten of all cervical spine injuries. They occur at all levels of participation. Fortunately, the number of patients suffering spinal cord injury is relatively small. Neurological injuries may range from transient quadriparesis through to complete quadriplegia. The decision to allow sportsmen to return to sport following a cervical spine injury is complex. It is based on such factors as history, clinical examination, the nature of the injury, as well as age and other psychosocial factors. The evidence that exists to aid this decision process is at times conflicting. The aim of this presentation is to review some of the contentious issues that exist in the decision making by reference to case presentations of high level sportsmen who were treated following a variety of cervical spine injuries.

Methods: Four high-level rugby players (22–31 years old) presented with different cervical spine injuries sustained during sporting activities. Two subjects sustained a “stinger” and two a transient quadriparesis which rapidly resolved. Radiological evaluation included assessment of spinal canal diameter.¹

Results: Two had a C5-6 disc bulge with developmental spinal stenosis. A third had a congenital fusion C2-3 with a disc bulge and developmental stenosis at C3-4. Case 4 had degenerative disc disease at C5-6. All were treated non-operatively and returned to sport. All suffered a recurrence of the neurological symptoms and subsequently underwent an anterior interbody fusion (Case 4 for subluxation of C6-7). Three successfully resumed rugby six months after surgery while one elected not to continue.

Discussion: The decision to allow a patient to return to contact sports following a cervical spine injury may be difficult. The four cases presented highlight some of these contentious issues such as transient neurological deficit and the effect that surgery may have on a patient’s ability to return safely to sport. A review of the literature may assist in the decision making.^1,2 This may be conflicting and difficult to interpret. Neurological signs, instability, displacement, fusion of more than one level and occipito-atlanto-axial pathologies are considered absolute contraindications.³