Aims

Cauda equina syndrome (CES) can be associated with chronic severe lower back pain and long-term autonomic dysfunction. This study assesses the recently defined core outcome set for CES in a cohort of patients using validated questionnaires.

To determine whether neurophysiological electrical pedicle testing (EPT) is a useful aid in the detection of malpostioned pedicle screw tracts

EPT data from 246 screws in 32 spinal operations on 32 patients over a 5 year period (2009–2014) were recorded and analysed. In addition to physical palpation, a ball-tipped electrode delivered stimuli and the output was recorded by evoked electromyogram (EMG). When breach threshold values were recorded, the surgeon rechecked the tract for breaches and responded appropriately. In addition, standard motor evoked potential (MEP) and sensory evoked potential(SEP) spinal cord monitoring was performed.

There were 24(9.8%) pedicle breaches by tract testing and 8(3.3%) by screw testing. In 11 instances in 7 patients where the tract testing showed a breach, the tract was redirected and subsequent screw testing showed adequate integrity of the pedicle. The total time for tract and screw testing was 25 seconds.

There were no associated changes in MEP or SEP monitoring with any of the recorded pedicle breaches and none of the patients had any post-operative neurological deficit.

EPT for the pedicle screw and tract is a safe, simple, practical and reliable technique which improves the accuracy of screw placement. Further studies would be required to confirm (and possibly revise) the threshold levels and to demonstrate whether EPT reduces the risk of misplaced screws or post-operative neurological deficit.

Aim:

An analysis of significant neuromonitoring changes (NMCs) and evaluation of the efficacy of multimodality neuromonitoring in spinal deformity surgery.

Introduction and aims: Surgical decompression for lumbar stenosis entails a risk of iatrogenic instability. Consequently, laminectomy has been largely superseded by the more conservative procedure of fenestration, but the decompression may be compromised. We describe an additional technique of undercutting laminectomy, which conserves stability while maximising decompression, and the results are presented.

Method: Forty-nine patients with lumbar spinal stenosis were treated by fenestration, medial facetectomy and removal with curved osteotomes of the ventral aspect of the lamina superior to the involved facets together with the attached ligamentum flavum. The results were assessed at a mean follow-up period of three years and four months using walking distance and a pain analogue scale as outcome measures, and surgical complications were recorded. The radiological results were assessed in 25 patients by measurement on MRI scan of the spinal canal cross-sectional area pre- and post-operatively.

Results: Ten patients had undercutting laminectomy at one level, 19 at two levels, 14 at three levels and four at four levels. Medical co-morbidity was present in most patients; 11 were ASA 1, 25 ASA2 and 11 ASA 3. Pre-operatively, all patients reported leg pain or numbness and 20 patients reported back pain. All but one had limited walking distance, the mean being 564 metres (range 5m–8000m). Post-operatively the mean pain score was 3.3 and the mean walking distance 762 metres. Forty-one patients said they felt the operation had been worthwhile and six said they did not. Surgical complications occurred in five patients, consisting of dural tear in four patients (repaired with no sequelae) and a wound haematoma requiring drainage in one patient. The mean spinal canal cross-sectional area at the level of maximal stenosis pre-operatively was 28mm² and postoperatively was 75mm², giving a mean increase of 133%. No patients had any evidence of iatrogenic instability as judged by the development of degenerative spondylolisthesis or scoliosis.

Conclusion: The technique described achieves excellent decompression of the stenotic lumbar canal as measured radiologically, while largely preserving the facet joints. In relation to published reports on fenestration and medial facetectomy alone, the clinical results are at least as good.

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 influence of timing of surgery on functional outcomes following spinal cord injury remains controversial. Animal studies suggest that the rate, degree, and duration of cord compression are the principal determinants of spinal cord injury (SCI) severity and prognosis for recovery. Delamarter et al, (J Bone Joint Surg Am 1995) have shown that when experimental cord compression in dogs is relieved within 1 hour, full motor recovery can be achieved. It is suggested by some clinically based research that definitive surgical treatment for unstable injuries results in fewer sequelae than prolonged immobilization and allows more rapid entry into rehabilitation. It is however the timing of this surgery which remains controversial. It has been suggested that early surgical management promotes neurological recovery by limiting secondary damage caused by inflammation, oedema, ischemia and instability. To date few studies have found a link between neurological recovery and timing of surgery (Fehlings, et al; Spine 2001).

Methods Data was gathered retrospectively by chart review of patients referred to the Princess Alexandra hospital with spinal cord injury. Patients were age matched into high and low velocity groups. This data was studied to assess the effects of energy of injury and timing of surgical intervention on neurological outcome. Patients either had anterior, posterior, or combined surgery, external immobilization or traction depending on the preference of the treating surgeon.

Results A cohort of 43 patients all of whom had spinal cord injury was retrospectively studied. Of these, 21 had a high energy injury (eg. MVA) and 21 had a low energy injury (eg. rugby). 28 had anterior stabilization 7 had traction, 4 had external immobilization 2 had a combined anterior / posterior fixation and 1 had posterior stabilization. The data suggest that the prognosis for recovery following a spinal cord injury is unrelated to the energy involved. The low energy group improved on average 0.6 ASIA grades (SEM 0.16) while the high energy improved 0.7 ASIA grades (SEM 0.17). The timing of definitive intervention for patients with incomplete cord lesions was shown to significantly (p=0.029) effect ultimate functional outcomes. Those with early (within 8hrs) intervention improved an average of 1.4 ASIA grades (SEM 0.21) and those with late intervention improved 0.6 ASIA grades (SEM 0.19). This effect was present in both high and low energy injury groups.

Discussion The timing of definitive intervention for spinal cord injury is still controversial. However there is Class II evidence that early surgery can be done safely in a patient with spinal cord injury (Fehlings, et al; Spine 2001). The findings from this retrospective study suggest that early surgical intervention may improve neurological recovery.

Introduction The purpose of this prospective controlled study was to define indications and analyse the clinical and radiographic results of cages in the surgical treatment of traumatic cervical spine instability.

Methods 53 patients were treated by monosegmental anterior discectomy and interbody fusion using either autologous tricortical iliac crest bone graft and cervical spine locking plate (CSLP) (bone graft group, n= 26) or Syncage-C (Synthes) filled with autologous cancellous bone grafts and CSLP (cage group n=27). Indications for surgery were traumatic cervical spine instability were classified by the cervical fracture classification of Blauth et al¹ as B1, B2, B3, C2 or C3 fractures. Intraoperative parameters (operative time, blood loss radiation time and intra- and perioperative complications) were documented. Prior to surgery and at follow-up (6 and 12 months) evaluation included measurement of neck pain, shoulder/arm pain and Neck Pain Disability Index (NPDI). Neurological function was assessed using the ASIA scale. Radiographic evaluation included plain X-rays, flexion-extension views and CT-scans. Patient satisfaction was measured on a five-point Likert scale.

Results There was no statistically significant difference between the two groups in the demographic data. One patient in the bone graft group was not available for the 1-year follow-up evaluation; however, all patients were available for the 2-year follow-up. Operation time was significantly shorter (p< 0.05) in the cage group (67 +/− 6 min) than in the bone graft group (78 +/− 9 min). After 6 and 12 months there was no difference between both groups in pain or NPDI, neurological and overall outcome. The neurological improvement of the two groups was not statistically different. Although the cage group showed a trend for better maintenance of lordosis after 12 months, there was no statistically significant difference between groups in all radiographic parameters. There were no implant-related complications during the follow-up. General complications included one patient with eczema due to the stiff collar (cage group) and one patient with pneumonia (cage group). Complications associated with the harvesting of iliac crest bone grafts included 14 patients (9 patients in the bone graft group, 5 patients in the cage group) with prolonged pain (> 3 months) at the donor site, one superficial wound healing problem (bone graft group) which healed under conservative treatment and one hematoma (bone graft group) which required additional surgery.

Discussion Cages offer a valid alternative to a tricortical iliac crest bone graft in the surgical treatment of mono-segmental traumatic cervical spine instability. Although there was no significant difference between the cage and the bone graft group in the functional and radiographic outcome, less donor site morbidity and a shorter operation time make cages cost effective in this selected group of patients. Although the cages are expensive, less donor site morbidity, shorter operation time and reduced hospital stay might result in cost-effectiveness of this implant.