Lightning Podiums: Spinal Potpourri - 803B

Presented by: A. Kasis

Author(s):

M. Mawdsley(1), C. Jensen(1), A. Kasis(1)

(1) Northumbria NHS Trust, Orthopaedic Spine Surgery, Ashington, United Kingdom

Abstract

Introduction: Bone morphogenic protein 2 (BMP-2) are often used to enhance spinal fusion, and improve patients' outcomes. Severe post-operative radiculitis has been associated with the use of BMP-2. The inflammatory properties of BMP-2 seem to result in new post-operative radicular symptoms, however the mechanism of this is not fully understood. It is also unclear if BMP-2 has a direct effect on C reactive protein (CRP) levels, and if so for how long. The aim of this study is to monitor the effects of BMP-2 on CRP levels following spinal fusion. To our knowledge, this is the first study investigating the effect of BMP-2 in this way.

Methods: A prospective study of 45 consecutive patients who underwent lumbar spinal fusion for degenerative spine conditions. All patients had their CRP checked before surgery, 4 days after surgery and 2 weeks after surgery. Twenty-five patients underwent Anterior Lumbar Interbody Fusion (ALIF) using half a large dose of BMP-2 (LARGE KIT 8 mL with solution concentration of 1.5 mg/mL) - Group 1. Twenty patients underwent spinal fusion using iliac crest bone graft (ICBG) without using BMP-2 and were regarded as the control group - Group 2;10 of them whom underwent Posterior Lumbar Interbody Fusion(PLIF) using ICBG, and 10 others who underwent ALIF using ICBG.

Results: The mean pre-operative CRP for patients who underwent fusion with BMP-2 (Group 1) was 3 (range 1-12), the mean CRP after 4 days was 103.32 (range 66-252). At 2 weeks post-operatively the mean CRP was 5.65 (range 1-15). The mean pre-operative CRP for patients who had spine fusion without BMP-2 (All Group 2) was 3 (range 1-14). The mean CRP at 4 days was 97.3 (range 26-225). At 2 weeks the mean CRP was 13.4 (range 1-11). Further sub-analysis of Group 2 showed a mean pre-operative CRP of PLIF patients with ICBG was 2 (range 1-5), at 4 days the mean was 89 (range 84-122), and at two weeks the mean was 23 (5-104). The patient with CRP of 104 at 2 weeks was found to have a wound infection and was treated with antibiotics. The mean preoperative CRP for patients who had ALIF with ICBG was 1 (range 1-14), the mean CRP at 4 days was 97.5 (26-225), and the mean CRP at 2 weeks was 4.88 (range 1-11).

Conclusion: There was no statistical difference between the pre-operative CRP between the BMP-2 group and ICBG group. Similarly, there was no statistical difference between the CRP at 4 days and 2 weeks between the two groups. It appears that despite BMP being associated with post-operative inflammation in some reports, we did not find it to have an effect on the post-operative CRP levels - an acute phase protein and validated marker of acute inflammation.