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Many early cervical total disc replacements (TDRs) produced motion through a ball-and-socket action, with metal endplates articulating with a plastic core. PEEK is used increasingly for spinal implants due to its mechanical properties and lack of artifact on imaging. A cervical TDR was designed with commercially pure titanium-coated PEEK endplates and a biconvex zirconia toughened alumina ceramic core. The purpose of this study was to compare this PEEK-on-ceramic TDR to anterior cervical discectomy and fusion (ACDF) to treat single-level cervical disc degeneration. This was a prospective, nonrandomized, multicenter Food and Drug Administration (FDA) Investigational Device Exemption (IDE) trial comparing the investigational group to a propensity-matched historic control group. Patients received the PEEK-on-ceramic Simplify® Cervical Artificial Disc (n=150 patients from 16 sites). The historic control group included 117 propensity-matched ACDF patients from an earlier cervical TDR IDE trial employing the same inclusion/exclusion criteria. All patients were treated for single-level symptomatic cervical disc degeneration. The primary outcome was a composite 5-point success classification at 24-month follow-up requiring: >15 point (of 100) improvement in Neck Disability Index (NDI) score; 2) maintenance/improvement in neurologic status; 3) no device failure; 4) no reoperation/revision/removal and/or supplemental fixation at the index level, and 5) no major adverse events. Outcome measures included NDI, visual analog scale (VAS) assessing neck and arm pain, neurological status, adverse events and subsequent surgery. Radiographic assessment included flexion/extension range of motion. Facet joints were assessed at 24 months comparing pre- to postoperative MRI images using a published 4-point scale. Evaluations were performed preoperatively and postoperatively within 2 and 6 weeks, and 3, 6, 12 and 24 months. The control was propensity match with ACDF patients from an earlier TDR vs ACDF trial, which used the same inclusion criteria and primary outcome assessments. The overall composite success rate was significantly greater in the TDR group vs ACDF (93.0% vs 73.6%; p<0.001). Mean NDI, neck pain and arm pain scores improved significantly in both groups at all follow-up points. Mean NDI scores in the TDR group were significantly lower than ACDF scores at all follow-up points all p<0.01). Secondary surgical intervention was undertaken in 4 (2.7%) patients at the index level in the TDR group and 6 (5.1%) in the ACDF group. There were no significant differences in the rates of serious adverse events when comparing the two groups. The mean segmental range of motion of the treated level in the TDR group was 7.3° prior to surgery. This increased to 8.6° at 3-month follow-up and continued to increase to 9.6° at 24 months (p<0.001). Facet joint assessment by MRI at 24-month follow-up in the TDR group showed little change from preoperative. The results of this study found that the Simplify® Cervical Artificial Disc produced outcomes similar or superior on some measures, including superiority in the composite success classification, compared with ACDF, for the treatment of single-level symptomatic cervical disc degeneration. ROM at the treated level increased from the preoperative value and was maintained throughout follow-up. Safety of the PEEK-on-ceramic disc was established with no device failures in the series. These results support that the device is a viable alternative to ACDF. Simplify Cervical Disc Replacement (Approved for this indication) [ABSTRACT FROM AUTHOR]

Interspinous process distraction (IPD) devices aim to alleviate back and leg pain by limiting extension and unloading the 3-joint complex at the affected lumbar level. IPDs may offer a treatment option for painful degenerative disc disease (DDD) that is not yet indicated for fusion or disc replacement. To compare the safety and effectiveness of IPD and nonoperative treatment after 2 years for the treatment of moderate lumbar DDD. A prospective, randomized, controlled FDA IDE clinical trial at 23 US centers (ClinicalTrials.gov: NCT00456378). A total of 278 patients with moderate low back pain for less than 1 year and radiographic evidence of single-level DDD between L2 and L5 who failed at least 6 weeks but less than 6 months of conservative management were randomized and treated with investigational IPD (n=181) or control nonoperative treatment (n=97). The primary endpoint was Overall Success, a composite variable that included: 1) Oswestry Disability Index (ODI) score improvement of ≥ 15 points; and 2) no serious adverse event (AE) caused by the implant or by both the implant and surgical procedure (IPD) or caused by the nonoperative treatment (control); and 3) no secondary surgery (IPD) or treatment surgery (control) at the involved level. Additional safety and effectiveness endpoints included back and leg pain numerical (0-20) rating scales, SF-36 PCS/MCS, AEs and secondary surgeries. Investigational treatment consisted of the IPD implantation (without decompression) and nonoperative treatments, as necessary. Control treatment consisted of information/ education on low back pain, medication, physical therapy, and epidural and/or facet joint steroidal injections. Clinical and radiographic assessments were performed preoperatively, intra-operatively, and postoperatively up to 2 years. Statistical analyses used Bayesian methods with non-informative priors. Last observation was carried forward (LOCF) for patients lost to follow-up including patients receiving surgery (control crossovers) or additional surgery (IPD investigational) at the involved level. Baseline demographic characteristics and outcomes scores were not statistically different between the two groups, except back pain (16.8 for investigational vs 16.1 for control, p=0.033). The IPD rate of Overall Success at 24-months was statistically superior to control (observed rate of 63.0% vs 13.4%, respectively; posterior probability of superiority (pps) > 99.9%). The improvement in outcomes for IPD was statistically superior to control (pps > 99.9%) for: ODI (26.4 vs 1.1), back pain (8.4 vs 1.2), leg pain (4.9 vs -1.1, PCS (12.6 vs.1.4), and MCS (4.4 vs -0.8). Spinous process bony erosion increased slowly to 33.7% (61/181) of patients but was not related to clinical outcomes. Treatment-related serious AEs in the control group were associated with increasing low back pain. Fifteen (8.3%) IPD and 34 (35.1%) control patients experienced a treatment-related serious AE. Twenty (11.0%) IPD patients had secondary surgery and 10 (10.3%) control patients had treatment surgery at the index level. After 6 months of nonoperative treatment, control patients had the option to crossover to IPD: 57 (58.8%) control patients had crossed over by 24 months. These analyses support the superiority of this IPD over conservative care for moderate back pain in appropriately selected patients. DIAM™ Spinal Stabilization System (Investigational/Not approved) [ABSTRACT FROM AUTHOR]