Background: A common problem achieving lumbar spinal fusion is developing a pseudarthrosis. The current gold standard in achieving fusion is the use of autograft from pelvis or posterior elements of the spine. However the potential limitations of insufficient quantity and donor site morbidity have led to the use of bone graft alternatives such as DBM which contains osteoinductive BMPs.

Aims & Methods: A prospective randomized control trial comparing the effectiveness of Demineralised Bone Matrix (DBM Putty)/autograft composite with autograft in lumbar postero-lateral or 270 degree spinal fusion.

35 patients were required for the study. They were randomized to have DBM and autograft on one side of the posterior approach and autograft alone on other side of the same approach. Patients were followed up with interval radiographs for total of 24mons. To date 32 patients have been recruited and with an average follow up a15.3 months. The mineralization of fusion mass lateral to the instrumentation on each side was graded as Absent, Mild (< 50%), Moderate (> 50%) or Complete fusion (100%). The assessment was made by independent orthopaedic consultant and a musculoskeletal radiologist who were blinded to graft assignment.

Results: The sex distribution was 17:15 male to females with a mean age of 55.2 (21–87years) and an average follow up of 15.3mons (3–24mons). 50% of patients had single level fusion and the remainder had more than one level fusion. At 12months, on the side of DBM 28% had complete fusion, 65% had moderate fusion, and 7% had no fusion mass. During the same period on the other side (non DBM side) approx 25% did not show any sign of fusion. There was no correlation with number of levels, age or sex.

Conclusions: Osteoinductive properties of DBM would appear to enhance the consolidation of the lumbar spinal fusion. DBM reduces the amount of harvested autograft graft and also minimises the morbidity of donor site complications.

Aim: To assess the outcome of patients with chronic discogenic lumbar back pain who underwent intradiscal electro thermal therapy (IDET).

Design: A prospective longitudinal study

Subjects: Patients undergoing IDET in our unit between April 2000 and October 2007 were included in the study after assessment with discography and diagnostic imaging. Discographic concordant symptoms with subsequent abolition with local anaesthetic led to inclusion in the study regardless of discogram volume.

Outcome Measures: Subjects were assessed preoperatively with VAS pain scores, SF36, demographic data and pain diagrams. Then were then reassessed postoperatively with the, VAS pain scores SF36, employment status and subjective outcome at 6, and 12 months.

Results: 83 patients were treated with IDET. We had a follow up rate of 75% leaving a cohort of 65 patients. Mean follow up 7.6 months.

Overall there was a mean improvement in pain VAS scores of 1.9 (p=0.0875).

SF36 scores showed minimal improvement in both physical and mental parameters and there was minimal improvement in subjective outcome in 55% of patients.

However it was observed that a small subgroup of patients (30%) aged less than 40 with low volume positive discography and single level disease mean pain VAS scores improved by 3.78 from 7.52 to 3.74. 72% of these patients reported a subjective improvement in symptoms and SF36 scores improved significantly compared to the overall group.

Further analysis also revealed that the use of pain diagrams when interpreted according to the principles of Mann et al was the predictive value.

Conclusions: Patient selection seems to be crucial in determining a successful outcome using IDET. We still perform this procedure on those patients aged less than 40 with single level disease, positive low volume discography, no facet joint arthritis and an organic pre procedure pain diagram.