Biomechanical research progress of interspinous process device in lumbar degenerative disease / 国际外科学杂志

The implantation of interspinous process device is a minimal invasive surgical procedure for degenerative lumbar spinal diseases. At present, a variety of interspinous process devices designed can be subdivided into three categories based on different application principles: interspinous distraction device, interspinous fixation device and interspinous fusion device. The interspinous distraction devices distract interspinous interspace, enlarge spinal canal area and alleviate neurological symptom, which are mainly applied for lumbar spinal stenosis with intermittent neurogenic claudication. Interspinous fixation device has been used as an alternative technique to the pedicle screw fixation in lumbar interbody fusion due to gripping and fixating to spinous process. Interspinous fusion device utilizes rigid fixation to support fusion, which can be used as not only simple distraction device but also additional instrumentation for direct decompression and interbody fusion. All types of interspinous process devices are different in biomechanical characteristics due to its application concept. In this review, the author mainly focus on biomechanical research progress of interspinous process device in lumbar degenerative disease.

Role of Coflex as an Adjunct to Decompression for Symptomatic Lumbar Spinal Stenosis

STUDY DESIGN: Prospective cohort study. PURPOSE: To assess whether additional implantation of Coflex following spinal decompression provided better clinical outcomes compared to decompression alone for symptomatic lumbar spinal stenosis (LSS) and to determine whether improvement in clinical outcomes correlated with changes in the radiological indices studied. OVERVIEW OF LITERATURE: Literature on benefits of additional Coflex implantation compared to decompression alone for symptomatic LSS is limited. METHODS: Patients with symptomatic LSS who met the study criteria were offered spinal decompression with Coflex implantation. Those patients who accepted Coflex implantation were placed in the Coflex group (n=22); while those opting for decompression alone, were placed in the comparison group (n=24). Clinical outcomes were assessed preoperatively, six-months, one-year and two-years postoperatively, using the Oswestry disability index, 100 mm visual analogue scale (VAS)-back pain and VAS-leg pain, and short form-36 (SF-36). Radiological indices (disc height, foraminal height and sagittal angle) were assessed preoperatively, six months, one year, and two years postoperatively. RESULTS: Both groups showed statistically significant (p<0.001) improvement in all the clinical outcome indicators at all points in time as compared to the preoperative status. However, improvement in the Coflex group was significantly greater (p<0.001) than the comparison group. Changes in the radiological indices did not correlate significantly with the improvement in clinical outcome indicators. CONCLUSIONS: Additional Coflex implantation after spinal decompression in symptomatic LSS offers better clinical outcomes than decompression alone in the short-term. Changes in radiological indices do not correlate with the improvements in clinical outcomes after surgery for symptomatic LSS.