Silicate-substituted calcium phosphate ceramic bone graft replacement for spinal fusion procedures.

STUDY DESIGN: Retrospective study. OBJECTIVE: To assess the clinical and radiographical outcomes in spinal fusion procedures using silicate-substituted calcium phosphate (Si-CaP). SUMMARY OF BACKGROUND DATA: Si-CaP is a newer-generation synthetic ceramic designed to maximize osteoinduction and osteoconduction. METHODS: This is a retrospective analysis of a prospectively collected patient database including 108 patients (204 individual spinal levels). Different surgical procedures performed included 25 anterior cervical discectomy and fusions, 17 posterior cervical fusions, 7 combined anterior and posterior cervical fusions, 10 thoracic fusion surgeries, 18 transforaminal lumbar interbody fusions with 12 axial lumbar interbody fusions, 11 transpsoas discectomy and fusions, and 8 combined thoracolumbar fusion procedures. Si-CaP was used as bone extender without any additional graft material, bone marrow aspirate, or bone morphogenetic protein. Clinical outcomes were assessed using the visual analogue scale (VAS), Oswestry Disability Index, and Neck Disability Index. Fusion was determined by the presence of bony bridging on 2 consecutive sections in at least 2 planes on computed tomographic imaging. RESULTS: At a follow-up of 12 (± 4.7) months, 90% of all patients demonstrated radiographical fusion. Fusion rates were highest in the cervical spine (97%) followed by thoracic and lumbar spines (86% and 81%, respectively). There were significant improvements in all clinical outcome measures-Oswestry Disability Index, 11.1 (± 10.2) and Neck Disability Index, 9.0 (± 11.4); VAS-back, 3.1(± 3.0); VAS-leg, 3.5 (± 3.6); VAS-neck, 3.7 (± 2.5); and VAS-arm 4.0 (± 3.2). There was no radiographical loosening of instrumentation due to infection or nonunion in this series, and no subsequent revisions for nonunion were required. CONCLUSION: Si-CaP is an alternative to autogenous bone graft in spinal arthrodesis procedures. At 12-month follow-up, we detected high levels of bony fusion using Si-CaP in combination with various surgical spinal techniques.

Lumbar juxtafacet cyst resection: the facet sparing contralateral minimally invasive surgical approach.

STUDY DESIGN: A retrospective review. OBJECTIVE: To report our approach and results using a contralateral minimally invasive spinal surgical muscle splitting approach that allows visualization of the cyst without extensive removal of the adjacent facet joint. SUMMARY OF BACKGROUND DATA: The use of tubular retractors for spinal surgery can potentially minimize tissue injury. Contralateral approaches may be beneficial in visualizing pathology that is located adjacent or under the facet joint. This approach has not been reported previously. METHODS: Sixteen consecutive patients were treated using this approach using tubular retractors and the operating microscope. A retrospective chart and imaging review was conducted to determine operative and clinical measures. Subsequently, patients were contacted to obtain long-term clinical follow-up. RESULTS: Nine patients had an excellent and 5 had a good outcome, with median follow-up of 18 months, 2 patients were lost due to lack of follow-up. The mean operative time was 105 minutes and in all cases the blood loss was <40 mL. No postoperative instability was noted. CONCLUSIONS: A contralateral approach using a tubular retractor system provides excellent visualization of the facet cyst allowing safe cyst resection and nerve root decompression without compromising the facet joint. Larger case series with longer follow-up are needed to assess stability.