Browsing by Author "Sasso, Rick"

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    A comparison of the shock-absorbing properties of cervical disc prosthesis bearing materials
    (Elsevier, 2011) Dahl, Michael C.; Jacobsen, Stephen; Metcalf, Newton; Sasso, Rick; Ching, Randal P.; Department of Orthopaedic Surgery, IU School of Medicine
    BACKGROUND DATA: Cervical arthroplasty offers theoretical advantages over traditional spinal fusion, including elimination of adjacent segment disease and elimination of the risk of pseudoarthrosis formation. Initial studies of cervical arthroplasty have shown promising results, however, the ideal design characteristics for disc replacement constructs have not been determined. The current study seeks to quantify the differences in the shock absorption characteristics of three commonly used materials in cervical disc arthroplasty. METHODS: Three different nucleus materials, polyurethane (PU), polyethylene (PE) and a titanium-alloy (Ti) were tested in a humidity- and temperature-controlled chamber. Ten of each nucleus type underwent three separate mechanical testing protocols to measure 1) dynamic stiffness, 2) quasi-static stiffness, 3) energy absorption, and 4) energy dissipation. The results were compared using analysis of variance. RESULTS: PU had the lowest mean dynamic stiffness (435 ± 13 N/mm, P < .0001) and highest energy absorption (19.4 ± 0.1 N/mm, P < .0001) of all three nucleus materials tested. PU was found to have significantly higher energy dissipation (viscous damping ratio 0.017 ± 0,001, P < .0001) than the PE or TI nuclei. PU had the lowest quasi-static stiffness (598 ± 23 N/mm, P < .0001) of the nucleus materials tested. A biphasic response curve was observed for all of the PU nuclei tests. CONCLUSIONS: Polyurethane absorbs and dissipates more energy and is less stiff than either polyethylene or titanium. LEVEL OF EVIDENCE: Basic Science/Biomechanical Study. CLINICAL RELEVANCE: This study characterizes important differences in biomechanical properties of materials that are currently being used for different cervical disc prostheses.
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    Intraosseous basivertebral nerve ablation for the treatment of chronic low back pain: a prospective randomized double-blind sham-controlled multi-center study
    (Springer, 2019-04-30) Fischgrund, Jeffrey S.; Rhyne, Alfred; Franke, Jörg; Sasso, Rick; Kitchel, Scott; Bae, Hyun; Yeung, Christopher; Truumees, Eeric; Schaufele, Michael; Yuan, Philip; Vajkoczy, Peter; DePalma, Michael; Anderson, David G.; Thibodeau, Lee; Meyer, Bernhard; Orthopaedic Surgery, School of Medicine
    PurposeTo evaluate the safety and efficacy of radiofrequency (RF) ablation of the basivertebral nerve (BVN) for the treatment of chronic low back pain (CLBP) in a Food and Drug Administration approved Investigational Device Exemption trial. The BVN has been shown to innervate endplate nociceptors which are thought to be a source of CLBP.MethodsA total of 225 patients diagnosed with CLBP were randomized to either a sham (78 patients) or treatment (147 patients) intervention. The mean age within the study was 47 years (range 25–69) and the mean baseline ODI was 42. All patients had Type I or Type II Modic changes of the treated vertebral bodies. Patients were evaluated preoperatively, and at 2 weeks, 6 weeks and 3, 6 and 12 months postoperatively. The primary endpoint was the comparative change in ODI from baseline to 3 months.ResultsAt 3 months, the average ODI in the treatment arm decreased 20.5 points, as compared to a 15.2 point decrease in the sham arm (p = 0.019, per-protocol population). A responder analysis based on ODI decrease ≥ 10 points showed that 75.6% of patients in the treatment arm as compared to 55.3% in the sham control arm exhibited a clinically meaningful improvement at 3 months.ConclusionPatients treated with RF ablation of the BVN for CLBP exhibited significantly greater improvement in ODI at 3 months and a higher responder rate than sham treated controls. BVN ablation represents a potential minimally invasive treatment for the relief of chronic low back pain.Graphical abstract These slides can be retrieved under Electronic Supplementary Material. Open image in new window