The spine journal : official journal of the North American Spine Society
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Clinical Trial
Ten-year survival and clinical outcome of the AcroFlex lumbar disc replacement for the treatment of symptomatic disc degeneration.
We have previously reported on the osseointegration, stability, and preserved motion of the AcroFlex lumbar disc replacement (LDR) in a nonhuman primate model. Detailed biomechanical testing of the device predicted implant survival for at least 10 years of in vivo use. Significant improvements in the clinical outcome were reported at 2 years. However, mechanical failure of the polyolefin rubber was detected by fine-cut computed tomography (CT) in a number of subjects within 2 years. As a result, no further devices were implanted. ⋯ The cumulative survival was 60.7% at 10 years when the first revision surgery was taken as the end point. The etiology of the implant failure prompting the revision included failure of osseointegration, midsubstance elastomeric tears, and osteolysis. Further use of this implant is not justified. The incidence of adjacent-level disc degeneration for the AcroFlex was comparable with that observed adjacent to the spinal fusion. Salvage procedures involving conversion to spinal fusion are technically demanding, but appear to improve outcomes modestly.
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Besides their clinical impact, the economic impact of health care-related adverse events (AEs) is significant. Although a number of studies have attempted to estimate the economic impact of AEs, few have directly linked costs to clinician-reported event severity. ⋯ In this surgical spine cohort, AEs accounted for 16% of the total cost of in-hospital care. Higher severity AEs were progressively more costly on a per-case basis; however, the more frequent lower severity events (ie, Grade I and II) also had a substantial aggregate cost (43%). These results suggest that a strong business case exists for patient safety strategies focused not only on severe AEs but also on the reduction of lower severity events that may be more amenable to prevention efforts.
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Comparative Study
Biomechanical evaluation of stand-alone lumbar polyether-ether-ketone interbody cage with integrated screws.
Stand-alone interbody cages with integrated screws potentially provide a biomechanically stable solution for anterior lumbar interbody fusion (ALIF) that alleviates the need for additional exposure for supplemental fixation, thereby reducing the chance of additional complications and morbidity. ⋯ Biomechanical testing revealed that the stand-alone cage with integrated screws provides more immediate stability than a cage alone and provides equivalent stability to ALIF constructs with supplemental fixation in lateral bending and axial rotation. Additional flexion-extension rigidity of the anterior cage maybe realized by the addition of a spinous process plate that was found to be as stable as supplemental bilateral PS.