Purpose:This study evaluated the results after one year from Orthotrac pneumatic vest (OPV) vs. EZ form brace as an additional therapy in patients with discopathy and leg pain. Our hypothesis was that the OPV would result in greater pain relief and increased self-reported functionality than the EZ.
Study Design/Setting:Prospective randomized clinical trial with follow-up at 6, 12, 26 and 52 weeks. This study was reviewed and approved by the Institutional Review Board at Presbyterian Hospital in Dallas, Texas.
Patient Sample:Patients (93) with back pain failing 4 weeks of conservative care, confirmed discopathy and radiating leg pain were solicited. Inclusion required ability to stand upright and have consistent relief lying down. Candidates (87) were initially evaluated. A subgroup (25) did not enter therapy because of intervening clinical improvement, travel distance or change in interest. Sixty-two were participants.
Outcome Measures: Self-reported visual analog scale (VAS) and Oswestry scores were primary outcomes.
Methods:Consenting patients received an OPV or EZ based on prospective randomization scheme under separate security. Assessment was by independent evaluator at 6, 12, 26 and 52 weeks. Once randomized, the patient saw the principal investigator, blinded to assessment and outcomes, for fitting. Analysis was by repeated measures ANOVA. A secondary analysis of change scores between the initial and 52-week outcome was by unpaired t-test. A logit model was created to define patient characteristics of successful outcome as improvement „d25% in VAS.
Results:A total of 21 patients failing conservative care elected to have surgery. Another 5 voluntarily withdrew. Despite randomization methods, an initial difference in pain levels (OPV-VAS 60¡Ó23; EZ-VAS 42¡Ó21; p „T 0.045) remained. No initial differences in Oswestry scores (p „T 0.28) were noted. The 36 non-operated patients were evaluated on primary outcomes. Repeated measures ANOVA on the groups found both improved with time. VAS showed significant group-time interaction effect in favor of OPV (F=3.08, p=0.031). VAS difference scores between the initial and 52-week evaluations were 40.1¡Ó27 for OPV and 19.4¡Ó21.8 for EZ (p=0.014). For Oswestry they were 11.1¡Ó18.3 for OPV and 11¡Ó10.7 for the EZ (p=0.985). Three logit variables were statistically significant. They were ¡§group¡¨ (p=0.008), SF-36 mental health (p=0.021) and energy/fatigue scores (p=0.012).
Discussion: Both groups improved in pain and function over time, consistent with results of other studies. Use of OPV in discopathy patients with leg pain resulted in a significantly greater improvement in pain levels. The greatest improvement was during the initial 12-week interval. A significant group-time interaction favoring the OPV was observed. Logit suggested that use of the OPV had a 30% greater probability of success. A 10-point increase in mental health and energy/fatigue scores was associated with a 25% and 29% increased likelihood of success, respectively.
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