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Various total disc replacement (TDR) designs have been compared to anterior cervical discectomy and fusion (ACDF) with favorable short and long-term outcomes in FDA-approved investigational device exemption (IDE) trials. The unique design of M6-C, with a compressible viscoelastic nuclear core and an annular structure, has previously demonstrated favorable clinical outcomes through 24 months. To evaluate the long-term safety and effectiveness of the M6-C compressible artificial cervical disc and compare to ACDF at 5 years. Prospective, multicenter, concurrently and historically controlled, FDA-approved IDE clinical trial. Subjects with one-level symptomatic degenerative cervical radiculopathy were enrolled and received M6-C (n=160) or ACDF (n=189) treatment as part of the IDE study. Safety outcomes were evaluated at 5 years for all subjects. The primary effectiveness endpoint was available at 5 years for 113 M6-C subjects and 106 ACDF controls. The primary endpoint of this analysis was composite clinical success (CCS) at 60 months. Secondary endpoints were function and pain (neck disability index, VAS), physical quality of life (SF-36, SF-12), safety, neurologic, and radiographic assessments. Propensity score subclassification was used to control for selection bias and match baseline covariates of the control group to the M6-C subjects. Sixty-month CCS rates were estimated for each treatment group using a generalized linear model controlling for propensity score. At 5 years postoperatively, the M6-C treatment resulted in 82.3% CCS while the ACDF group showed 67.0% CCS (superiority p=.013). Secondary endpoints indicated that significantly more M6-C subjects achieved VAS neck and arm pain improvements and showed maintained or improved physical functioning on quality-of-life measures compared to baseline assessments. The M6-C group-maintained flexion-extension motion, with significantly greater increases from baseline disc height and disc angle than observed in the control group. The rates of M6-C subsequent surgical interventions (SSI; 3.1%) and definitely device- or procedure-related serious adverse events (SAE failure; 3.1%) were similar to ACDF rates (SSI=5.3%, SAE failure=4.8%; p>.05 for both). Subjects treated with the M6-C artificial disc demonstrated superior 5-year achievement of clinical success when compared to ACDF controls. In addition, significantly more subjects in the M6-C group showed improved pain and physical functioning scores than observed in ACDF subjects, with no difference in reoperation rates or safety outcomes. [ABSTRACT FROM AUTHOR]

Degenerative spondylolisthesis (DS) with lumbar spinal stenosis (LSS) is commonly treated with decompression and fusion. The LimiFlex Dynamic Sagittal Tether (DST) is an investigational stabilization device for patients with DS and LSS. The purpose of this study is to assess the clinical and radiographic outcomes of decompression and DST compared to transforaminal lumbar interbody fusion (TLIF) for patients with DS and LSS. Multicenter prospective concurrently controlled study. Patients undergoing treatment (decompression and DST or TLIF stabilization) of Grade I Meyerding lumbar degenerative spondylolisthesis. Patients undergoing treatment (decompression and DST or TLIF stabilization) of Grade I Meyerding lumbar degenerative spondylolisthesis. Patients with single-level Grade I DS with LSS were enrolled in the FDA-IDE study (NCT03115983) comparing decompression with DST and decompression with TLIF. Clinical and radiographic outcomes were assessed at baseline and 6-week, 3, 6, 12 and 24-month follow-up. All propensity score (PS) selected patients who had 24-month follow-up were included in this interim analysis. Summary statistics are reported, as well as paired t-tests to assess within-group changes. At 24 months, 228 PS-selected patients (129DST/99TLIF) had clinical follow-up and 197 (117DST/80TLIF) had radiographic follow-up. Mean characteristics of DST and TLIF groupswere: age 65.5/64.1 yrs; BMI 28.1/30.5; CCI 0.43/0.41, respectively. Mean perioperative outcomes for DST/TLIF were: procedure time 112/189 min; EBL 53/232 mL; LOS 0.7/3.2 nights. A significant reduction at 24 months for mean VAS-leg/hip (79.5 to 22.9), VAS-back (66.8 to 19.0) and ODI (52.8 to 13.2) was reported for DST patients (all p < 0.01) with 91% achieving 15-point ODI improvement. TLIF patients demonstrated similar improvements for VAS-leg (80.6 to 24.4), VAS-back (68.1 to 26.1) and ODI (52.3 to 20.9) (all p < 0.01), with 80% achieving 15-point ODI improvement. While there was no difference at baseline, the DST group had lower ODI at all postoperative timepoints. Within the 24 months, 9% of each group had additional surgery at the index or adjacent level. At 24 months, the DST group had mean reductions of 1.7° ROM and 0.4mm translation in flexion/extension images compared to 3.8° and 1.0mm reductions in the TLIF group. Considering the index and adjacent segments together (IAS), the index segment accounted for 30% of IAS ROM at baseline and 27% at 24 months in the DST group compared to 29% at baseline and 13% at 24 months in the TLIF group. These results suggest that decompression with DST stabilization for spondylolisthesis can achieve significant clinical improvement as is expected with fusion, without an increase in reoperations during the 24 months postoperative period. Similarly, statistically significant improvements in patient-reported outcomes were demonstrated in each group, with lower disability scores in the DTB group at all postoperative timepoints. Imaging demonstrated no increased instability in the DST group with maintained distribution of motion between the index and adjacent segments. While these groups were PS-selected, further analyses should include quantitative comparison between groups with PS-adjusted differences per the predefined composite clinical success criteria for a definitive comparison of outcomes. LimiFlex Dynamic Sagittal Tether (Investigational/Not Approved). [ABSTRACT FROM AUTHOR]

Degenerative spondylolisthesis (DS) with lumbar spinal stenosis (LSS) is commonly treated with decompression and fusion. The LimiFlex Dynamic Sagittal Tether (DST) is an investigational stabilization device for patients with DS and LSS. Assess return to work (RTW) and activities of daily living (ADL) receiving either decompression and DST stabilization (D+DST) or decompression and transforaminal lumbar interbody fusion (D+TLIF). Interim analysis from a multicenter, concurrently controlled study. Patients undergoing treatment (D+DST or D+TLIF) of Grade I Meyerding lumbar DS. Propensity score (PS) selected patients with 12-month follow-up were included. Time to RTW and activities of daily living, as well as Oswestry disability index (ODI). PS-selected IDE study subjects with 12 months of follow-up were included in this analysis. Study records queried for work status preoperatively and at 12 months, as well as time to RTW and ADL, and change in disability (Oswestry Disability Index; ODI) at 12 months vs preop. Outcomes were compared using student's t-tests. PS-selected subjects totaled 267 (136 D+DST, 131 D+TLIF). Preoperatively, 49% of D+DST and 43% of D+TLIF subjects were working (p=0.14) and 7% D+DST and 11% D+TLIF were not working due to spinal condition (NWSC) (p=0.13). At 12 months postop, 44% of D+DST and 34% of D+TLIF subjects were working (p=0.05) and 2% D+DST and 10% D+TLIF were NWSC (p<0.01). Proportion of D+DST NWSC was significantly lower 12 months postop compared to preop (p=0.02). Mean±SD RTW time for D+DST/D+TLIF subjects was 5.4±6.6/11.8±9.6 weeks (p<0.01) and return to ADL time was 5.5±6.5/10.0±9.5 weeks (p<0.01). Mean±SD reduction in disability at 12 months from baseline was 38.1±18.4 for the D+DST group and 31.8±20.7 for the D+TLIF group (p<0.01) with effect sizes of -2.1 and -1.5, respectively. The primary objective of surgery for symptomatic DS is resolution of symptoms so patients can return to their normal ADL and work. Both D+DST and D+TLIF treated patients demonstrated a significant reduction in disability at 12-month follow-up. Significantly faster RTW and ADL were observed for D+DST compared to D+TLIF patients, by an average of more than 5 weeks. The proportion of D+DST patients NWSC was significantly less than at 12 months. Results indicate a significant advantage of earlier recovery for the D+DST patients allowing earlier RTW and earlier increase in ADLs compared to D+TLIF, with similar or greater improvements in disability after one year for patients treated with decompression and stabilization for symptomatic DS. Longer-term follow-up assessment with propensity score-adjusted outcomes will demonstrate whether this advantage and long-term outcomes are durable and generalizable. This abstract does not discuss or include any applicable devices or drugs. [ABSTRACT FROM AUTHOR]

Study Design. Prospective randomized controlled trial. Objective. Compare range of motion (ROM) and adjacent segment degeneration (ASD) following cervical disc arthroplasty (CDA) versus anterior cervical discectomy and fusion (ACDF) at 20-year follow-up. Summary of Background Data. Anterior cervical discectomy and fusion is the standard of treatment for single-level cervical disc degeneration causing radiculopathy. CDA is claimed to reduce shear strain, and adjacent-level ROM changes are hypothesized to hasten ASD with ACDF. Materials and Methods. This study collected data on 47 patients randomized to ACDF or CDA. Lateral cervical spine radiographs were evaluated preoperatively, postoperatively, and at 20 years for alignment, ROM, ASD, and heterotopic ossification. Results. Eighty-two percent (18/22) of CDA patients and 84% (21/25) of ACDF patients followed up at 20 years. At 20 years, total cervical (C2--C7) ROM was statistically different between the CDA and fusion groups (47.8° vs. 33.4°, P=0.005). Total cervical ROM was not significantly different between preoperative and 20-year periods following CDA (45.6° vs. 47.4°, P=0.772) or ACDF (40.6° vs.33.0°, P=0.192). Differences in postoperative and 20-year index-level ROM following CDA were not significant (10.1° vs. 10.2°, P=0.952). Final ASD grading was statistically lower following CDA versus ACDF at both adjacent levels (P<0.005). Twenty-year adjacent-level ossification development was increased following ACDF versus CDA (P<0.001). Polyethylene mean thickness decreased from 9.4 mm immediately postoperatively to 9.1 mm at 20-year follow up (P=0.013). Differences in adjacent-level ROM from preoperative to 20-year follow-up in both the ACDF and CDA groups did not meet statistical significance (P>0.05). Conclusions. Cervical disc arthroplasty maintains index-level and total cervical ROM with very long-term follow-up. Total cervical ROM was higher at 20 years in CDA relative to ACDF. CDA results in lower rates of ASD and adjacent-level ossification development than ACDF. [ABSTRACT FROM AUTHOR]

Case: A 61-year-old woman with recurrent left L5 radiculopathy underwent revision L4-5 decompression complicated by incidental durotomy requiring primary repair. Postoperative course was complicated by wound drainage and headache. Repeat magnetic resonance imaging demonstrated cerebrospinal fluid dissecting a plane deep to the dura mater but superficial to the arachnoid, with the collection compressing the cauda equina in an atypical horizontal and linear fashion. Nonoperative treatment was ineffective, and she required revision decompression and dural repair. Conclusion: Spine surgeons should recognize this finding on postoperative imaging as a potential sign of an incomplete dural repair necessitating return to the operating room. [ABSTRACT FROM AUTHOR]

i-FACTOR is a composite bone substitute material consisting of a P-15 synthetic collagen fragment adsorbed onto an organic bone mineral and suspended in an inert biocompatible hydrogel carrier. Previous analyses of the US FDA IDE study demonstrated the benefits of i-FACTOR compared to local autograft bone in single-level ACDF at 12- and 24-months postoperative. We report 6-year clinical and radiological outcomes of post-approval study. Subjects from a completed, prospective, randomized, controlled, multicenter clinical trial that was conducted at 22 North American sites were enrolled in a post-approval study and we report 6-year outcomes. Of 319 subjects that participated in the IDE study, 220 were enrolled into post-approval 6 years follow-up autograft (n = 114) or i-FACTOR (n = 105) in a cortical ring allograft. Radiological, clinical, and patient-reported outcomes. Subjects completed prospective, randomized, controlled, multicenter clinical trial that was conducted at 22 North American sites were enrolled into post-approval study 6 years follow-up. Fusion rates at 72 months were 99.0% in i-FACTOR subjects and 98.2% in autograft subjects, with a difference of 0.8% (95% C.I., (95% CI -2.3%, 4.0%). Mean improvement in NDI in i-FACTOR subjects was 28.56 (95% CI 24.79, 32.33) compared to 29.17 (95% CI 25.46, 32.88) in autograft subjects, with a difference of -0.61 (2.793) (95% CI -6.10, 4.88). Neurologic success rate at 72 months was 95.89% in i-FACTOR subjects and 93.33% in autograft subjects, with a difference of 2.6% (95% CI, -4.70%, 9.81%). Overall success rate was 68% in i-Factor and 62% in autograft subjects. Safety outcomes were similar between the 2 treatment groups. Secondary surgery at any cervical level occurred in 20 (18.9%) i-FACTOR subjects and 23 (20.2%) autograft subjects (p=0.866). Pain and SF-36 outcomes were similar between the groups at all study visits. There were no adverse reactions associated with i-FACTOR. At 6 years, i-FACTOR in ACDF resulted in similar outcomes compared to local autograft. Safety outcomes are acceptable and clinical and functional outcomes for i-FACTOR in the previous studies are confirmed. I-Factor (Approved for this indication) [ABSTRACT FROM AUTHOR]

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]