The purpose of this study was to establish the relationship between the anterior and posterior spinal elements and identify which morphological changes in the ageing spine has the greatest influence in determining the loss of lumbar lordosis.

Study Design: Prospective Cohort Study.

Summary of Background Data: It has previously been suggested that fulcrum bending radiographs (Cheung et al Luk 1997) and traction radiography under anaesthetic (Davis et al 2003) predict the flexibility and correction obtained following surgery better than conventional supine bending radiographs.

Objective: To compare fulcrum bending radiographs and traction radiographs for the prediction of surgical correction of idiopathic scoliosis.

Subjects: The study was based on 16 patients with a diagnosis of idiopathic scoliosis who underwent corrective surgery.

Outcome measures: The Cobb angle of the major curve was compared on the standing AP and fulcrum bending radiograph taken in the pre-op assessment clinic, the traction film undertaken under anaesthetic immediately prior to surgery and the first post operative standing radiograph taken. The post operative correction of the major curve was analysed using regression techniques and adjusted for the base line curve angle of the major curve.

Results: The results were presented as an estimate of the parameter coefficient in the model associated with 95% confidence intervals. The median pre-operative Cobb angle of the major curve was 69 degrees, on the fulcrum bending film was 47 degrees, on the traction film was 30 degrees, and on the first post operative film was 30 degrees. There was no evidence to suggest that the fulcrum Cobb had an effect on the post operative correction of the major curve. There was however evidence to suggest that the traction Cobb angle had an effect on the post operative correction of the major curve (parameter estimate 0.87) 95% CI (0.174, 1.399), T value = 2.83, P = 0.016.

Conclusion: Traction radiographs under anaesthetic better predict the surgical correction obtained in adolescent idiopathic scoliosis compared to fulcrum bending radiographs. These two techniques have not been directly compared before.

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.