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Study design A prospective, randomized, multicenter Food and Drug Administration Investigation Device Exemption study using total disc replacement as surgical treatment of degenerative disc disease at 1 or 2 contiguous levels of the cervical spine. Objective To evaluate the safety and effectiveness of total disc replacement at single or 2 contiguous levels through 48 months of follow-up. Summary of background data Cervical total disc replacement has been shown to be a safe and effective alternative to anterior cervical discectomy and fusion at 24 months. Its motion-preserving capabilities may avoid accelerating adjacent segment pathology and thereby lower the rate of associated complications. Methods Patients were randomized in a 2:1 ratio (total disc replacement [TDR]: anterior cervical discectomy and fusion [ACDF]) at 24 sites. Ultimately, 164 patients received TDR at 1 level and 225 patients received TDR at 2 contiguous levels. An additional 24 patients (15 one-level, 9 two-level) were treated with TDR as training cases.Outcome measures included neck disability index, visual analogue scale neck and arm pain, Short Form 12-item Health Survey (SF-12) Mental Composite Score (MCS) and Physical Composite Score (PCS), range of motion, major complication rates, and secondary surgery rates. Patients received follow-up examinations at regular intervals through 4 years after surgery. Results Preoperative characteristics were statistically similar for the 1- and 2-level patient groups. Four-year follow-up rates were 83.1% (1-level) and 89.0% (2-level). There was no statistically significant difference between 1- and 2-level TDR groups for all clinical outcome measures. Both TDR groups experienced significant improvement at each follow-up when compared with preoperative scores. One case of migration was reported in the 2-level TDR group. Conclusion A 4-year post hoc comparison of 1- and 2-level TDR patients concurrently enrolled in a 24-center, Food and Drug Administration Investigation Device Exemption clinical trial indicated no statistical differences between groups in clinical outcomes, overall complication rates, and subsequent surgery rates. Level of evidence 1.

Four novel antiviral WIN compounds, that contain a methyl tetrazole ring as well as isoxazole, pyridazine or acetylfuran rings, have had their structures determined in human rhinovirus serotype 14 at 2.9 A resolution. These compounds bind in the VP1 hydrophobic pocket, but are shifted significantly towards the pocket pore when compared to previously examined WIN compounds. A putative water network at the pocket pore is positioned to hydrogen bond with these four WIN compounds, and this network can account for potency differences seen in structurally similar WIN compounds.

This paper describes the use of a custom-configured computer-controlled firearms training simulator to measure perception response (reaction) time (RT) to a stimulus in which the degree of threat presented is a manipulable variable across trials. The computer records the number of frames of videotape traversed between the point of presentation of the threat in the video stimulus and the point at which the subject responds by drawing the firearm. For the purposes of data analysis, these frame-count measures are converted to RT measurements. Example data are presented that capture perception RT at both thedraw-stimulus and thefire-stimulus points in situations for which either only one threat or more than one threat exists. Other elements, such as degree of threat and accuracy of response, provide additional data.

Study design Prospective randomized clinical trials. Objective To compare the outcome data with respect to clinical success rates and incidence of adjacent level disease (ALD) in patients after total disc arthroplasty (TDA) or anterior cervical fusion (ACDF) for 1- and 2-level cervical disc disease. Summary of background data Previously published studies have provided evidence that ACDF procedure for cervical degenerative disc disease (DDD) may increase the stress on the nonoperated adjacent cervical segments, thus possibly increasing the risk of degeneration at these levels. The theoretical assumption that TDA may reduce the incidence of future ALD by preserving motion at the affected segments has, however, never been validated by clinical evidence. Methods One hundred seventy patients with established symptomatic cervical disc disease at 1 or 2 levels participated in 3 prospective randomized clinical trials at 2 institutions. Participating subjects were randomized to receive TDA (treatment; n = 113) or ACDF (control; n = 57) by 6 independent investigating surgeons. Visual analogue pain scores (0-100), Neck Disability Index, neurological examination, and cervical spine radiographs were collected at enrollment and then 6 weeks and 3, 6, 12, 24, 36, and 48 months after surgery. Patients with persistent symptoms during the follow-up period were investigated for adjacent segment disease (ASD) with computed tomography/magnetic resonance imaging of the cervical spine, neurophysiology, and subsequent active interventions. Results At the median follow-up of 42 months (range: 28-54 months), 9 (14.3%) ACDF and 19 (16.8%) TDA patients developed and were actively treated for ASD. Osteopenia dust energy x-ray absorptiometry T scores of -1.5 to -2.4) (P = 0.04; 95% confidence interval [CI]: 0.007-0.223) and concurrent lumbar degenerative disease (P = 0.02; 95% CI: 0.003-0.196) significantly increased the risk of ASD. Conclusion The risk of developing adjacent segment degeneration was equivalent at median 38 months after both ACDF and TDA procedures in cervical DDD. Osteopenia and concurrent lumbar DDD significantly increase the risk of ALD.

A prospective, randomized, multicenter, Food and Drug Administration-regulated Investigational Device Exemption clinical trial.To evaluate the safety and effectiveness of the ProDisc-L (Synthes Spine, West Chester, PA) lumbar total disc replacement compared to circumferential spinal fusion for the treatment of discogenic pain at 1 vertebral level between L3 and S1.As part of the Investigational Device Exemption clinical trial, favorable single center results of lumbar total disc replacement with the ProDisc-L have been reported previously.Two hundred eighty-six (286) patients were treated on protocol. Patients were evaluated before and after surgery, at 6 weeks, 3, 6, 12, 18, and 24 months. Evaluation at each visit included patient self-assessments, physical and neurologic examinations, and radiographic evaluation.Safety of ProDisc-L implantation was demonstrated with 0% major complications. At 24 months, 91.8% of investigational and 84.5% of control patients reported improvement in the Oswestry Low Back Pain Disability Questionnaire (Oswestry Disability Index [ODI]) from preoperative levels, and 77.2% of investigational and 64.8% of control patients met theor =15% Oswestry Disability Index improvement criteria. Overall neurologic success in the investigational group was superior to the control group (91.2% investigational and 81.4% control; P = 0.0341). At 6 weeks and 3 months follow-up time points, the ProDisc-L patients recorded SF-36 Health Survey scores significantly higher than the control group (P = 0.018, P = 0.0036, respectively). The visual analog scale pain assessment showed statistically significant improvement from preoperative levels regardless of treatment (P0.0001). Visual analog scale patient satisfaction at 24 months showed a statistically significant difference favoring investigational patients over the control group (P = 0.015). Radiographic range of motion was maintained within a normal functional range in 93.7% of investigational patients and averaged 7.7 degrees.ProDisc-L has been found to be safe and efficacious. In properly chosen patients, ProDisc-L has been shown to be superior to circumferential fusion by multiple clinical criteria.