Results of hemivertebrectomy and fusion for symptomatic thoracic disc herniation

We retrospectively analysed ten consecutive patients (age range 32-77 years) treated surgically from 1994 to 1999 for symptomatic thoracic disc herniation between the 6th and 12th thoracic discs. Clinically, eight patients had varying grades of back pain and eight patients had paraparesis. Radiography showed calcification in 50% of the herniated discs. Two patients had two-level thoracic disc herniation. Hemivertebrectomy followed by discectomy and fusion was carried out in all patients. Instrumentation with cages was performed in eight patients and bone grafting alone in two patients. The average follow-up was 24 months (range 13-36 months). Six patients had an excellent or good outcome, three had a fair outcome and one had a poor outcome. One patient had atelectasis, which recovered within 2 days of surgery. Another patient had developed complete paraplegia, detected at surgery by SSEPs, and underwent resurgery following magnetic resonance (MR) scan with complete corpectomy and instrumented fusion. At 2 years, she had a functional recovery. The patient with poor outcome had undergone a previous discectomy at T9/10. He developed severe back pain and generalised hyper-reflexia following corpectomy and fusion for disc herniation at T10/11. We advocate anterior transthoracic discectomy following partial corpectomy for symptomatic thoracic disc herniation between the 6th and 12th thoracic discs. This procedure offers improved access to the thoracic disc for an instrumented fusion, which is likely to decrease the risk of iatrogenic injury to the spinal cord.