Objective: This study investigates whether fixation down to lumbar spine only can prevent pelvic tilt compared to pelvic fixation, in the surgical treatment of Duchenne Muscular Dystrophy (DMD).

Design: Retrospective and prospective clinical outcome study, with long-term follow up.

Materials and Methods: Nineteen cases of DMD with scoliosis had early stabilisation (mean age 11.5 years, range 9–16) with sublaminar wires and rods, and pedicle screws up to the lumbar spine. This cohort was followed up for a mean 4.2 years (3–10 years). 31 cases in another centre had late stabilisation (mean age 14.5 years, range 10–17), with Luque rod and sublaminar wire fixation, and pelvic fixation using L-rod (22 cases) configuration or Galveston technique (9 cases) and were followed up for 4.6 years (0.5–11.5 years). Post-op morbidity, Cobb angle correction and pelvic obliquity data were collected retrospectively and prospectively for comparison.

Results: In the lumbar fixation group FVC was 58%, the mean Cobb angle and pelvic obliquity were 19.8° and 9° preoperative, 3.2° and 2.2° direct postoperative, and 5.2° and 2.9° at final follow up respectively. The mean estimated blood loss was 3.3 litres and average hospital stay 7.7 days. In the pelvic fixation group FVC was 44%, the mean Cobb angle and pelvic obliquity were 48° and 19.8° preoperative, 16.7° and 7.2° direct postoperative, and 22° and 11.6° at final follow up respectively. The mean blood loss (4.1 litres) and the average hospital stay (17 days) were significantly higher (p< 0.05) compared to the lumbar fixation group. The pelvic fixation group had higher complication rate at the lower end of fixation. No progression of the pelvic obliquity was noted in the lumbar fixation group during follow up

Conclusion: Lumbar fixation may be adequate for scoliosis in DMD, if the stabilisation is performed early, before the pelvis becomes tilted, and scoliosis becomes significant. The caudal pedicular fixation in the lumbar spine stops rotation of the spine around the rods, and prevent pelvic tilt to occur. Pelvic fixation may be necessary in presence of established pelvic obliquity and larger scoliosis, but is associated with higher morbidity and complications.

Objective: To demonstrate possible advantages of combined (motor and sensory) versus single modality (either motor or sensory) intraoperative spinal cord monitoring

Design: Retrospective and prospective clinical study

Materials and Methods: One hundred and twenty-six consecutive operations in 97 patients had peroperative monitoring the lower limb motor evoked potentials (MEPs) to multi- pulse transcranial electrical stimulation (TES), and tibial nerve somatosensory evoked potentials (SEPs). Seventy-nine patients had spinal deformity surgery, and eighteen had surgery for trauma, tumor or disc herniation

Results: Combined motor and sensory monitoring was successfully achieved in 104 of 126 (82%) operations. Monitoring was limited to MEPs alone in two, and SEPs alone in eighteen cases. Neither MEPs nor SEPs were obtainable in two cases with Friedreich’s ataxia. Significant evoked potentials (EP) changes occurred in one or both modalities in 16 patients, in association with instrumentation (10) or systemic changes (6). After appropriate remedial measures, SEPs recovered either fully or partially in all cases (8/8) and MEPs in 10/15. New neurodeficits developed post-operatively in six of the sixteen patients with abnormal EPs, including two in whom SEPs had either not changed or recovered fully after remedial measures. One patient developed S3–5 sensory loss despite full recovery of both SEPs and MEPs. Two patients without neurological consequences had persistent MEP changes. Normal MEPs (but not SEPs) at the end of the operation correctly predicted the absence of new motor deficits. There were no false negative MEP changes.

Conclusion: MEPs are more sensitive than SEPs, but may rarely raise false positive alarm. SEPs are unaffected by anaesthetics and can be monitored more frequently. Combined monitoring is safe, complimentary to each other, and increases sensitivity and predictivity of adverse neorological consequences. True incidence of false positive MEP or SEP changes are difficult to define. Remedial measures after monitoring changes may help cord ischaemia to recover and absence of neurological deficit, therefore, may not indicate a false positive monitoring change.

Objective: To asses the outcome of hermivertebrectomy and fusion for symptomatic thoracic disc herniation.

Design: A retrospective case analysis

Subjects: Between 1993 and 1999, ten patients (M5, F5) were treated surgically for thoracic disc herniation by the two senior authors (JKW & SHM). The average age of patients at presentation was 5Oyears (range 32–77years). Two patients had two level disc herniations (total 12 disc herniation). The most common sites of disc herniation were at T10/11(4 patients). Duration of diffuse mid thoracic hock pain in eight patients varied from one week to six months. The initial neurological evaluation demonstrated weakness and spasticity of varying grades in eight patients, of which five had paraplegia and three had monoparesis. Sensory changes below the level of the lesion were found in eight patients. Sphincter dysfunction was noted in seven patients. Hemivertebrectomy followed by discectomy and fusion was carried out in all patients. Instrumentation with cages was performed in eight patients and only bone grafting in two patients. Spinal cord monitoring was used in all cases.

Outcome Measures: The average follow up was 24 months (range 13–36 months). Pre-operative and postoperative neurological grading was done using MRC grading for motor and sensory deficit. Asymptomatic patients with full activity were regarded as a successful outcome.

Results: Three patients had excellent, three had good, three had fair and one had poor outcome. Seven out of eight patients with cages had radiological fusion. The cage stabilises the segment and maintains the spinal height till bony fusion takes place. One patient with hone graft alone had recurrence of symptoms and had a re-surgery with a poor outcome. Six patients had residual back pain of varying degrees. One patient had atelectasis, which recovered within two days of surgery. One patient had suffered from complete paraplegia immediately after surgery detected by SSEPs. She underwent a MRI scan within the hour and was reoperated. She had complete corpectomy and instrumented fusion. At two years she was walking with a support.

Conclusion: Exposure of the norrnal tissue above and below herniated disc by hemivertebrectomy facilitates the safe removal of the disc and reduces the risk of further neurological damage. Cages were found to have advantages over autogenous strut only grafts. However, persistent back pain in some cases remains an unsolved problem.