Which Domains of the ODI Best Predict Change in Physical Function in Patients After Surgery for Degenerative Lumbar Spondylolisthesis?

STUDY DESIGN: A retrospective review. OBJECTIVE: The purpose of this study is to determine the differential improvement of the various individual items of the Oswestry Disability Index (ODI) and to determine their relationship to other measures of Health Related Quality of Life (HRQOL). SUMMARY OF BACKGROUND DATA: The ODI is an easily scored, common, 10-item questionnaire about symptoms relevant to lumbar spine pathology. It is not clear if all of the items can be reliably applied to spine surgery. The purpose of this study is to determine the differential improvement of the various individual items of the ODI and to determine their relationship to other measures of HRQOL. METHODS: Analysis of a prospective registry of patients treated at an academic medical center was undertaken. At baseline, standardized outcome measures including ODI and SF12 PCS were collected on all patients undergoing elective fusion surgery for degenerative spondylolisthesis. Multiple linear regressions were performed using change in SF12 PCS as the dependent variable and change in ODI components as the independent variables. RESULTS: Baseline and 1-year follow-up data were collected on 196 patients (mean age 60.4 years). There were statistically significant differences in improvement among ODI items. Surprisingly, the most improvement after surgery was noted in the standing, sex life, and social life domains. The least improvement was noted in the personal care, sleeping, and sitting domains. Linear regression for change in ODI components versus change in SF-12 PCS revealed a significant correlation (R = 0.353, P ≤ 0.001). The only retained domains in the final model were change in lifting, standing, and traveling as predictors for ΔPCS. CONCLUSION: All domains of the ODI do not improve equally after surgery for degenerative spondylolisthesis. Some of the domains that improve most (e.g., sex life) have no discernible relationship to the known pathophysiology of degenerative spondylolisthesis. Based upon these results, we conclude that the item bank and composite scoring of the ODI are inappropriate for evaluating quality of life in studies of surgically treated degenerative spondylolisthesis patients. LEVEL OF EVIDENCE: 3.

No difference in postoperative complications, pain, and functional outcomes up to 2 years after incidental durotomy in lumbar spinal fusion: a prospective, multi-institutional, propensity-matched analysis of 1,741 patients.

BACKGROUND: Incidental durotomies occur in up to 17% of spinal operations. Controversy exists regarding the short- and long-term consequences of durotomies. PURPOSE: The primary aim of this study was to assess the effect of incidental durotomies on the immediate postoperative complications and patient-reported outcome measures. STUDY DESIGN: Prospective study. PATIENT SAMPLE: A total of 1,741 patients undergoing index lumbar spine fusion were selected from a multi-institutional prospective data registry. OUTCOME MEASURES: Patient-reported outcome measures used in this study included back pain (BP-Visual Analog Scale), leg pain (LP-Visual Analog Scale), and Oswestry Disability Index. METHODS: A total of 1,741 patients were selected from a multi-institutional prospective data registry, who underwent primary lumbar fusion for low back pain and/or radiculopathy between January 2003 and December 2010. We collected and analyzed data on patient demographics, postoperative complications, back pain, leg pain, and functional disability over 2 years, with risk-adjusted propensity score modeling. RESULTS: Incidental durotomies occurred in 70 patients (4%). Compared with the control group (n=1,671), there was no significant difference in postoperative infection (p=.32), need for reoperation (p=.85), or symptomatic neurologic damage (p=.66). At 1- and 2-year follow-up, there was no difference in patient-reported outcomes of back pain (BP-Visual Analog Scale), leg pain (LP-Visual Analog Scale), or functional disability (Oswestry Disability Index) (p>.3), with results remaining consistent in the propensity-matched cohort analysis (p>.4). CONCLUSION: Within the context of an on-going debate on the consequences of incidental durotomy, we found no difference in neurologic symptoms, infection, reoperation, back pain, leg pain, or functional disability over a 2-year follow-up period.

Collagen and proteoglycan abnormalities in the GDF-5-deficient mice and molecular changes when treating disk cells with recombinant growth factor.

STUDY DESIGN: A magnetic resonance image, histologic, biochemical, and gene expression study was conducted to characterize the effects of growth and development factor-5 (GDF-5) deficiency on the health of the intervertebral disc. OBJECTIVE: To determine the effect of GDF-5 deficiency on extracellular matrix and gene expression on the intervertebral disc. SUMMARY OF BACKGROUND DATA: Developmental and degenerative changes in intervertebral disc are not fully understood. Molecular abnormalities and spontaneous mutations that lead to the deficiency in a normal protein have been useful in understanding the function of certain molecules and the role they play in the structure and health of certain tissues. Although the role of GDF-5 in the disc has not been elucidated, this factor may have an important role in the disc as a result of the well-documented effect of GDF-5 in other chondrogenic tissues. METHODS.: Intervertebral discs of 20-week-old GDF-5 (-/-) and (+/+) mice were examined radiographically, histologically, biochemically, and with gene expression studies. Cells isolated from GDF-5-deficient mouse discs were treated with recombinant GDF-5 and gene expression was subsequently analyzed. RESULTS: GDF-5 (-/-) mice demonstrated significantly lower T2-weighted signal intensity in the central region of their lumbar discs, and disc histology revealed loss of the normal lamellar architecture of the anulus fibrosus and a shrunken, disorganized nucleus pulposus. Biochemical analysis revealed decreased proteoglycan content but no appreciable change in total collagen content of the discs. Significant downregulation of both aggrecan and type II collagen mRNA, without an appreciable change in type I collagen expression, was noted on gene expression studies. Recombinant GDF-5 treatment of disc cells from the GDF-5-deficient mice resulted in a dose-dependent upregulation of the aggrecan and type II collagen genes. CONCLUSION: The intervertebral disc is markedly affected by GDF-5 deficiency. This relatively simple (single gene) system with a known molecular defect may be useful in studies designed to define the response of the intervertebral disc to treatment with growth factor in vivo.