2016 Volume 30 Issue 2 Pages 176-184
Object : We experienced 20 cases treated with X-STOP PEEK® for lumbar spinal canal stenosis, and report their preliminary results.
Materials and Methods : Twenty patients underwent insertion of an interspinous spacer (X-STOP PEEK®) for lumbar spinal canal stenosis, and postoperative neurological symptoms, Japanese Orthopedic Association (JOA) score, cross-sectional area of the spinal canal, and the height of the inter-vertebral space were evaluated.
Results : Of the 20 patients, 15 were males and 5 were female, and their age at operation was 53 to 82 years (mean : 73 years). The follow-up period was 12 to 38 months (mean : 24 months). The pre-operative JOA score was 4 to 15 (mean : 9.9), the 1-month post operative JOA score was 20 to 26 (mean : 24), and the JOA score recovery rate (R. R. %) was 61% to 96% (mean : 75%). The 1-year postoperative JOA score was 9 to 26 (mean : 23), and the R. R. was 13% to 96% (mean : 70%). The preoperative cross-sectional area of the spinal canal was 2.1 mm2 to 6.1 mm2 (mean : 4.2 mm2) and the inter-vertebral space was 3.2 mm to 5.5 mm (mean : 4.3 mm) ; the 1-year postoperative cross-sectional area of the spinal canal was 4.0 mm2 to 9.4 mm2 (mean : 6.1 mm2) and the inter-vertebral space was 4.5 mm to 8.7 mm (mean : 7.2 mm). One case (5%) had neurological deterioration due to fracture of a spinous process and dislocation of the X-STOP, and required conventional posterior decompression one year later ; two other cases (10%) had a fractured spinous process, of which one had neurological deterioration. No peri-operative complicationa occurred.
Conclusion : Insertion of an interspinous spacer (X-STOP PEEK®) for lumbar spinal canal stenosis improved the JOA score by increasing the cross-sectional area of the spinal canal and the inter-vertebral space at the 1-year follow-up. However, the effectiveness was slightly decreased on long-term follow-up. Fracture of the spinous process between the levels at which X-STOP was inserted induced neurological deterioration. Case selection should include those without an indication for conventional decompression surgery, to ensure cost-effective management.
