One-year follow up of a prospective case control study of 60 patients Does an interspinous device (CoflexTM) improve the outcome of decompressive surgery in lumbar spinal stenosis? One-year follow up of a prospective case control study of 60 patients By Tariq E. Awad Lecturer of Neurosurgery Suez Canal University 8-7-2010

Introduction and Rationale LSS due to degenerative changes is a disabling disease common in the elderly. Decompressive surgery was shown to be a successful in relieving symptoms of LSS & being superior to conservative treatment in long-term examinations . No clear evidence about the most effective technique of decompression or the extend of that decompression. Interspinous-based dynamic stabilization after decompression is currently being investigated as a good additional procedure which might improve the clinical outcome.

Device Information CoflexTM device is one of the dynamic interspinous implants (Paradigm Spine, LCC, New York, NY), formerly Interspinous ‘U’. It is a compressible U-shaped titan device It is interposed between the spinous process after decompressive surgery. First invented in 1994 by the French orthopaedic surgeon Jacques Samani as an alternative to arthrodesis, to protect adjacent levels after spinal surgery & for the protection of degenerative segments following decompressive surgery.

Aim of implanting Coflex interspinous devices Unload the facet joints. Restore foraminal height. Dynamic provide stability especially in extension but still allow motion in the treated segment stop the progressive course of degenerative disc disease and foster the healing of the least severe lesions.

Aim of implanting Coflex interspinous devices In vitro studies have demonstrated a reduction in facet joint forces by 68% and annulus pressures by 63%. (Swanson et al 2005) This procedure is fully reversible, leaving all subsequent surgical options open including disc replacement, full laminectomy and fusion.

Aim of the Work To evaluate the surgical outcomes of decompressive surgery in comparison to decompressive surgery & additional implantation of the CoflexTM interspinous Device to assess safety & efficacy of the implant.

Clinical Materials, Patients and Methods Study Design: A prospective controlled, non randomized, clinical trial Patient Population Between May 2008 and April 2010, At Suez Canal University Hospital (Ismailia, Egypt) 60 patients indicated for decompressive surgery were included in this study. Patients were categorized into 2 groups ( each had 30 patients): A) Group 1: undercutting-group (UC) B) Group 2: Coflex-Group (CO)

Methods

Surgical procedure

Results Distribution of the treated level in the Coflex-group & the undercutting –group.

Results ODI preoperatively & at each follow up in the 2 groups. All follow up scores are significant improved (p<0.001) compared to base line with no significant difference

Results VAS preoperatively and at each follow up in the two treatment groups. All follow up scores are significant improved (p<0.001) compared to base line with no significant difference Walking distance over time. All patients had a significant prolonged walking distance (p<0.001) with no significant main difference between the operation method was found.

Results Subjective satisfaction and subjective operation decision.

Case Examples 55 ys M c/o NC for 6 months WD 100 m

Conclusion After decompressive surgery for lumbar spinal stenosis, all measured parameters improved significantly (p<0.001) compared to base line, independent of the operation method. The additional placement of a CoflexTM interspinous device seems to be a safe procedure but did not improve the clinical outcome at the 12-month follow up interval. No difference in the patient satisfaction & the subjective operative decision was noted between the groups treated with or without CoflexTM implant.

Conclusion This study has a limitation in the short- term follow up period of 12 month, the missing randomization and the number of patient being included. While there is no current evidence of the efficacy of the Coflex device, we have to collect more data in a longer follow up

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