Preoperative Factors Predict Postoperative Trajectories of Pain and Disability Following Surgery for Degenerative Lumbar Spinal Stenosis.

STUDY DESIGN: Longitudinal analysis of prospectively collected data. OBJECTIVE: Investigate potential predictors of poor outcome following surgery for degenerative lumbar spinal stenosis (LSS). SUMMARY OF BACKGROUND DATA: LSS is the most common reason for an older person to undergo spinal surgery, yet little information is available to inform patient selection. METHODS: We recruited LSS surgical candidates from 13 orthopedic and neurological surgery centers. Potential outcome predictors included demographic, health, clinical, and surgery-related variables. Outcome measures were leg and back numeric pain rating scales and Oswestry disability index scores obtained before surgery and after 3, 12, and 24 postoperative months. We classified surgical outcomes based on trajectories of leg pain and a composite measure of overall outcome (leg pain, back pain, and disability). RESULTS: Data from 529 patients (mean [SD] age = 66.5 [9.1] yrs; 46% female) were included. In total, 36.1% and 27.6% of patients were classified as experiencing a poor leg pain outcome and overall outcome, respectively. For both outcomes, patients receiving compensation or with depression/depression risk were more likely, and patients participating in regular exercise were less likely to have poor outcomes. Lower health-related quality of life, previous spine surgery, and preoperative anticonvulsant medication use were associated with poor leg pain outcome. Patients with ASA scores more than two, greater preoperative disability, and longer pain duration or surgical waits were more likely to have a poor overall outcome. Patients who received preoperative chiropractic or physiotherapy treatment were less likely to report a poor overall outcome. Multivariable models demonstrated poor-to acceptable (leg pain) and excellent (overall outcome) discrimination. CONCLUSION: Approximately one in three patients with LSS experience a poor clinical outcome consistent with surgical non-response. Demographic, health, and clinical factors were more predictive of clinical outcome than surgery-related factors. These predictors may assist surgeons with patient selection and inform shared decision-making for patients with symptomatic LSS. LEVEL OF EVIDENCE: 2.

Calcification in human intervertebral disc degeneration and scoliosis.

Calcification is a pathological process that may lead to impairment of nutrient supply and disc metabolism in degenerative and scoliotic intervertebral discs (IVDs). The purpose of this study was to assess the calcification potential of IVDs in degenerative disc disease (DDD) and adolescent idiopathic scoliosis (AIS). For this purpose, 34 IVDs from 16 adult patients with DDD and 25 IVDs from 9 adolescent patients with AIS were obtained at surgery. The concave and convex parts of the scoliotic discs were analyzed separately. Von Kossa staining was performed to visualize calcium deposits, while type X collagen (COL X) expression associated with endochondral ossification was measured by immunohistochemistry. Alkaline phosphatase activity and calcium and inorganic phosphate concentrations were used as indicators of calcification potential. Results showed the presence of calcium deposits and COL X in degenerative and scoliotic IVDs, but not in control discs, and the level of the indicators of calcification potential was consistently higher in degenerative and scoliotic discs than in control discs. The results suggest that disc degeneration in adults is associated with ongoing mineral deposition and that mineralization in AIS discs might reflect a premature degenerative process.