Establishing a Gold Standard for Noninvasive Identification of Painful Lumbar Discs: Prospective Comparison of Magnetic Resonance Spectroscopy vs Low-Pressure Provocation Discography.

PURPOSE: Verifying lumbar disc pain can present a clinical challenge. Low-pressure provocative discography (PD) has served as the gold standard, although it is invasive and often a challenge to interpret. We reported that magnetic resonance spectroscopy (MRS) biomarkers accurately predict PD results in lumbar discs and improved outcomes for patients with surgery at positive MRS levels versus nonsurgery. To further substantiate MRS for diagnosing painful discs, we report a prospective comparison of 2 MRS-derived measures: NOCISCORE (pain) and SI-SCORE (degeneration severity). METHODS: Lumbar MRS and software-based postprocessing (NOCISCAN-LS, Aclarion Inc.) was performed in 44 discs in 14 patients (prospective cohort [PC]). PC data were compared to prior data used to establish the NOCISCORE (training cohort [TC]). The NOCISCORE was converted to an ordinal value (high/intermediate/low; NOCI+/mild/-) and compared against painful (P) versus nonpainful (NP) control diagnosis (PD) for 19 discs where PD was performed in the PC (12 NP; 7 P). Sensitivity, specificity, and positive and negative predictive values were calculated. The SI-SCORE was compared against MRI Pfirrmann Grades for 465 discs in 126 patients (PC plus TC). RESULTS: For the PC, MRS (NOCI+/-) compared to PD (P/NP) with an accuracy of 87% and sensitivity and specificity of 100%. The positive and negative predictive values of MRS were 100%. NOCISCOREs were significantly higher for PD+ versus PD- discs for PC and TC (P < 0.05), and the NOCISCORE distributions for PD+/- group were not statistically different between the PC and TC (P > 0.05). SI-SCORES differed between Pfirrmann Grades 1 and 2 (less degenerated) versus Grades 3 and 4 (more degenerated; P < 0.05), with a progressively decreasing trend with Pfirrmann Grades 1-5. CONCLUSION: These current data provide prospective confirmation of the predictive value of disc MRS for distinguishing painful discs and for assessing the disc structural integrity. CLINICAL RELEVANCE: NOCISCAN is an adoptable, noninvasive, and objectively quantitative test to improve management of low back pain patients.

Magnetic resonance spectroscopy (MRS) identification of chemically painful lumbar discs leads to improved 6-, 12-, and 24-month outcomes for discogenic low back pain surgeries.

PURPOSE: MRS was shown to reliably quantify relative levels of degenerative pain biomarkers, differentiating painful versus non-painful discs in patients with chronic discogenic low back pain (DLBP), and this correlates with surgical success rates. We now report results based on more patients and longer follow-up. METHODS: Disc MRS was performed in DLBP patients who subsequently received lumbar surgery. Custom post-processing (NOCISCAN-LS®; Aclarion Inc.) calculated disc-specific NOCISCORES® that reflect relative differences in degenerative pain biomarkers for diagnosing chemically painful discs. Outcomes in 78 patients were evaluated using Oswestry Disability Index (ODI) scores. Surgical success (≥ 15-point ODI improvement) was compared between surgeries that were "Concordant" (Group C) versus "Discordant" (Group D) with NOCISCORE-based diagnosis for painful discs. RESULTS: Success rates were higher for Group C versus Group D: 6 months (88% vs. 62%; p = 0.01), 12 months (91% vs. 56%; p < 0.001), and 24 months (85% vs. 63%; p = 0.07). Success rates for Group C surgeries were also higher than Group D surgeries in a variety of sub-group comparisons. Group C had a greater reduction in ODI from pre-operative to follow-up than Group D [absolute change (% change), (p)]: 6 months: - 35 (- 61%) versus - 23 (- 39%), (p < 0.05); 12 months: - 39 (- 69%) versus - 22 (- 39%), (p < 0.01); and 24 months: - 38 (- 66%) versus - 26 (- 48%), (p < 0.05). CONCLUSION: More successful, sustained outcomes were obtained when surgically treating chemically painful discs identified by NOCISCAN-LS post-processed disc MRS exams. Results suggest that NOCISCAN-LS provides a valuable new diagnostic tool to help clinicians better select treatment levels.

Cervical Disc Arthroplasty for Axial Neck Pain: Comparison of Outcomes to 2 Other Common Cervical Conditions.

BACKGROUND: Cervical disc arthroplasty (CDA) is an established treatment for degenerative disc disease with radiculopathy and/or myelopathy. There is, however, little published evidence of its effectiveness to relieve pain and improve function in patients with a primary diagnosis of axial neck pain. Such patients were excluded from all previous Food and Drug Administration clinical trials for CDA. We compare the outcomes of patients who underwent CDA for 3 common cervical conditions from 2003 to 2018. METHODS: Seven hundred and eighty-two CDA patients at a single site were grouped by primary diagnosis: predominant axial neck pain (ANP) (n = 257), predominant radiculopathy (RAD) (n = 331), or a combination of both (ANP + RAD) (n = 195). Mixed models for repeated measures predicted and analyzed scores at all time points, adjusting for diagnosis group, time point, and, if statistically significant, number of operative levels and demographic characteristics. Outcome measures included the Neck Disability Index, numerical pain scales (intensity plus frequency), the Veterans RAND 12 Item Health Survey (VR-12) Physical Component Score, the Mental Component Score, and reoperations. Patients were assessed preoperatively and postoperatively at 6 weeks, 3 months, 6 months, 1 year, and annually thereafter. RESULTS: At baseline, arm pain scores in the ANP group were statistically lower (P = .0002) than in the RAD and ANP + RAD groups, consistent with preoperative diagnoses. Surgeries included 40.8% 1-level, 41.6% 2-level, 14.7% 3-level, and 2.9% 4-level. For all outcome measures, improvements were statistically significant from baseline to each postoperative time point without statistical difference between the 3 diagnosis groups. In total, 45/782 patients (5.8%) underwent a secondary surgery: 3.5% ANP, 5.8% RAD, and 8.7% ANP + RAD. Days to reoperation did not statistically differ between groups (P = .489). CONCLUSIONS: Appropriately selected patients with predominant axial neck pain treated with CDA may achieve clinical and functional outcomes comparable to patients with a primary diagnosis of radiculopathy or of axial neck pain with concomitant radiculopathy. CLINICAL RELEVANCE: This study provides information that should help clinicians decide whether to offer CDA for patients with a primary diagnosis of axial neck pain and to appropriately counsel such patients about expected outcomes. LEVEL OF EVIDENCE: 4.

Multilevel Cervical Disc Arthroplasty: Long-Term Outcomes at 3 and 4 Levels.

BACKGROUND: Multilevel cervical degenerative disc disease in 2 or more segments poses treatment challenges. Anterior cervical discectomy and fusion is a viable treatment option, but one with high rates of adjacent segment disease and pseudoarthrosis. Cervical disc arthroplasty (CDA) is approved by the US Food and Drug Administration for the treatment of 1- and 2-level cervical pathology, with established long-term safety and effectiveness. Limited evidence exists for CDA at more than 2 levels. This study investigates the long-term outcomes of 3- and 4-level CDA out to 7 years. METHODS: In a retrospective review of prospectively collected data, patient demographics and surgical characteristics were collected. Patient-reported outcomes (PROs) were collected preoperatively and at 6 weeks, 3 months, 6 months, and 12 months postoperatively, and annually thereafter, including: Neck Disability Index (NDI), numeric rating scales for neck pain and arm pain, the Veterans Rand 12-item Health Survey physical component summary (PCS) score and mental component summary (MCS) score, and patient satisfaction scores. Secondary surgery data were also collected. Predictive methods using mixed-effects regression models were used to analyze the data. RESULTS: Data for 139 CDAs were available for evaluation (n = 116 three-level and n = 23 four-level). Statistical improvement was shown for all PRO scores at all postoperative intervals (P < .001). From preoperatively to 7 years postoperatively, mean NDI decreased from 57.9 to 31.3 (45.9% improvement), mean neck pain decreased from 15.6 to 7.9 (49.4% improvement), mean arm pain decreased from 12.2 to 5.6 (54.1% improvement), mean PCS increased from 29.2 to 41.4 (41.8% improvement), and mean MCS increased from 37.1 to 44.5 (19.9% improvement). Five (3.6%) 3-level patients underwent secondary surgery. Patient satisfaction exceeded 88% 7 years after surgery. CONCLUSION: Statistical improvement in PROs, with a low rate of secondary surgeries out to 7 years, demonstrates that 3- and 4-level CDA may be performed safely and effectively in appropriately selected patients. LEVEL OF EVIDENCE: 4.

Occurrence and clinical implications of heterotopic ossification after cervical disc arthroplasty with the Prestige LP Cervical Disc at 2 contiguous levels.

OBJECTIVE: The authors sought to assess the impact of heterotopic ossification (HO) on clinical outcomes and angular range of motion (ROM) after cervical disc arthroplasty (CDA) performed with the Prestige LP Cervical Disc (Prestige LP disc) at 2 levels. METHODS: HO was assessed and graded from 0 to IV for increasing severity on lateral neutral radiographs at each visit in 209 patients who underwent implantation of Prestige LP discs at 2 cervical levels in a clinical trial with extended 10-year follow-up. ROM was compared by using HO grade, and clinical outcomes were compared between HO subgroups (grade 0-II vs III/IV) based on HO severity at 2 and 10 years after surgery. RESULTS: The grade III/IV HO incidence at either or both index levels was 24.2% (48/198) at 2 years and 39.0% (57/146) at 10 years. No statistical difference was found in overall success; neurological success; or Neck Disability Index (NDI), neck pain, arm pain, or SF-36 Physical Component Summary (PCS) scores between the HO subgroups (grade 0-II vs III/IV) at either 2 or 10 years. The cumulative rate of possible implant-related adverse events (AEs) was higher in patients having grade III/IV HO at 2 years (56.3%) and 10 years (47.8%) compared with those having grade 0-II HO at 2 years (24.4%) and 10 years (17.9%), specifically in 2 subcategories: spinal events and HOs reported by the investigators. No statistical difference was found between the HO subgroups in possible implant-related serious AEs or secondary surgeries at the index or adjacent levels. The average angular ROMs at index levels were lower in subjects with higher-grade HO at 2 and 10 years. The average ROMs at the superior level were 8.8°, 6.6°, 3.2°, and 0.3°, respectively, for the HO grade 0/I, II, III, and IV groups at 10 years, and 7.9°, 6.2°, 3.7°, and 0.6°, respectively, at the inferior level. CONCLUSIONS: Radiographically severe (grade III or IV) HO after CDA with the Prestige LP disc at 2 levels did not significantly affect efficacy or safety outcomes (severe AEs or secondary surgeries). However, severe HO, particularly grade IV HO, significantly limited ROM, as expected.

Two-level cervical disc arthroplasty versus anterior cervical discectomy and fusion: 10-year outcomes of a prospective, randomized investigational device exemption clinical trial.

OBJECTIVE: The authors assessed the 10-year clinical safety and effectiveness of cervical disc arthroplasty (CDA) to treat degenerative cervical spine disease at 2 adjacent levels compared to anterior cervical discectomy and fusion (ACDF). METHODS: A prospective, randomized, controlled, multicenter FDA-approved clinical trial was conducted comparing the low-profile titanium ceramic composite-based Prestige LP Cervical Disc (n = 209) at two levels with ACDF (n = 188). Ten-year follow-up data from a postapproval study were available on 148 CDA and 118 ACDF patients and are reported here. Clinical and radiographic evaluations were completed preoperatively, intraoperatively, and at regular postoperative follow-up intervals for up to 10 years. The primary endpoint was overall success, a composite variable that included key safety and efficacy considerations. Ten-year follow-up rates were 86.0% for CDA and 84.9% for ACDF. RESULTS: From 2 to 10 years, CDA demonstrated statistical superiority over ACDF for overall success, with rates at 10 years of 80.4% versus 62.2%, respectively (posterior probability of superiority [PPS] = 99.9%). Neck Disability Index (NDI) success was also superior, with rates at 10 years of 88.4% versus 76.5% (PPS = 99.5%), as was neurological success (92.6% vs 86.1%; PPS = 95.6%). Improvements from preoperative results in NDI and neck pain scores were consistently statistically superior for CDA compared to ACDF. All other study effectiveness measures were at least noninferior for CDA compared to ACDF through the 10-year follow-up period, including disc height. Mean angular ranges of motion at treated levels were maintained in the CDA group for up to 10 years. The rates of grade IV heterotopic ossification (HO) at the superior and inferior levels were 8.2% and 10.3%, respectively. The rate of severe HO (grade III or IV) did not increase significantly from 7 years (42.4%) to 10 years (39.0%). The CDA group had fewer serious (grade 3-4) implant-related or implant/surgical procedure-related adverse events (3.8% vs 8.1%; posterior mean 95% Bayesian credible interval [BCI] of the log hazard ratio [LHR] -0.92 [-1.88, -0.01]). The CDA group also had statistically fewer secondary surgical procedures at the index levels (4.7%) than the ACDF group (17.6%) (LHR [95% BCI] -1.39 [-2.15, -0.61]) as well as at adjacent levels (9.0% vs 17.9%). CONCLUSIONS: The Prestige LP Cervical Disc, implanted at two adjacent levels, maintains improved clinical outcomes and segmental motion 10 years after surgery and is a safe and effective alternative to fusion.Clinical trial registration no.: NCT00637156 (clinicaltrials.gov).

Lumbar disc arthroplasty versus anterior lumbar interbody fusion: 5-year outcomes for patients in the Maverick disc investigational device exemption study.

OBJECTIVE: Despite evidence of its safety and effectiveness, the use of lumbar disc arthroplasty has been slow to expand due in part to concerns about late complications and the risks of revision surgery associated with early devices. More recently, FDA approval of newer devices and improving reimbursements have reversed this trend in the United States. Additional long-term data on lumbar disc arthroplasty are still needed. This study reports the 5-year results of the FDA investigational device exemption clinical trial of the Medtronic Spinal and Biologics' Maverick total disc replacement. METHODS: Patients with single-level degenerative disc disease from L4 to S1 were randomized 2:1 at 31 investigational sites. In the period from April 2003 to August 2004, 405 patients received the investigational device and 172 patients underwent the control procedure of anterior lumbar interbody fusion. Outcome measures included the Oswestry Disability Index (ODI), numeric rating scales (NRSs) for back and leg pain, the SF-36, disc height, interbody motion, heterotopic ossification (investigational device), adverse events (AEs), additional surgeries, and neurological status. Treatment was considered an overall success when all of the following criteria were met: 1) ODI score improvement ≥ 15 points over the preoperative score; 2) maintenance or improvement in neurological status compared with preoperatively; 3) disc height success, that is, no more than a 2-mm reduction in anterior or posterior height; 4) no serious AEs caused by the implant or by the implant and the surgical procedure; and 5) no additional surgery classified as a failure. RESULTS: Compared to that in the control group, improvement in the investigational group was statistically greater according to the ODI and SF-36 Physical Component Summary (PCS) at 1, 2, and 5 years; the NRS for back pain at 1 and 2 years; and the NRS for leg pain at 1 year. The rates of heterotopic ossification increased over time: 1.0% (4/382) at 1 year, 2.6% (9/345) at 2 years, and 5.9% (11/187) at 5 years. Investigational patients had fewer device-related AEs and serious device-related AEs than the control patients at both 2 and 5 years postoperatively. Noninferiority of the composite measure overall success was demonstrated at all follow-up intervals; superiority was demonstrated at 1 and 2 years. CONCLUSIONS: Lumbar disc arthroplasty is a safe and effective treatment for single-level lumbar degenerative disc disease, resulting in improved physical function and reduced pain up to 5 years after surgery.Clinical trial registration no.: NCT00635843 (clinicaltrials.gov).

Cervical disc arthroplasty: 10-year outcomes of the Prestige LP cervical disc at a single level.

OBJECTIVE: Food and Drug Administration-approved investigational device exemption (IDE) studies have provided level I evidence supporting cervical disc arthroplasty (CDA) as a safe and effective alternative to anterior cervical discectomy and fusion (ACDF). Long-term CDA outcomes continue to be evaluated. Here, the authors present outcomes at 10 years postoperatively for the single-level CDA arm of an IDE study (postapproval study). METHODS: The primary endpoint was overall success, a composite variable composed of five criteria: 1) Neck Disability Index score improvement ≥ 15 points; 2) maintenance or improvement in neurological status; 3) no decline in anterior or posterior functional spinal unit (FSU) height of more than 2 mm compared to 6 weeks postoperatively; 4) no serious adverse event (AE) caused by the implant or the implant and the surgical procedure; and 5) no additional surgery classified as a failure. Additional safety and effectiveness measures included numeric rating scales for neck pain and arm pain, SF-36 quality-of-life physical and mental components, patient satisfaction, range of motion, and AEs. RESULTS: From the reported assessments at 7 years postoperatively to the 10-year postoperative follow-up, the scores for all patient-reported outcomes, rate of overall success (without FSU), and proportion of patients at least maintaining their neurological function remained stable for the CDA group. Nine patients had secondary surgery at the index level, increasing the secondary surgery cumulative rate from 6.6% to 10.3%. In that same time frame, four patients experienced a serious implant or implant/surgical procedure-related AE, for a 10-year cumulative rate of 7.8%. Seven patients had any second surgery at adjacent levels, for a 10-year cumulative rate of 13.8%. Average angular motion at both the index and adjacent levels was well maintained without creating hypermobility. Class IV heterotopic ossification increased from 1.2% at 2 years to 4.6% at 7 years and 9.0% at 10 years. Patient satisfaction was > 90% at 10 years. CONCLUSIONS: CDA remained safe and effective out to 10 years postoperatively, with results comparable to 7-year outcomes and with high patient satisfaction.Clinical trial registration no.: NCT00667459 (clinicaltrials.gov).

Magnetic resonance spectroscopy (MRS) can identify painful lumbar discs and may facilitate improved clinical outcomes of lumbar surgeries for discogenic pain.

PURPOSE: The goal of this study was to refine clinical MRS to optimize performance and then determine whether MRS-derived biomarkers reliably identify painful discs, quantify degeneration severity, and forecast surgical outcomes for chronic low back pain (CLBP) patients. METHODS: We performed an observational diagnostic development and accuracy study. Six hundred and twenty-three (623) discs in 139 patients were scanned using MRS, with 275 discs also receiving provocative discography (PD). MRS data were used to quantify spectral features related to disc structure (collagen and proteoglycan) and acidity (lactate, alanine, propionate). Ratios of acidity to structure were used to calculate pain potential. MRS-SCOREs were compared to PD and Pfirrmann grade. Clinical utility was judged by evaluating surgical success for 75 of the subjects who underwent lumbar surgery. RESULTS: Two hundred and six (206) discs had both a successful MRS and independent pain diagnosis. When comparing to PD, MRS had a total accuracy of 85%, sensitivity of 82%, and specificity of 88%. These increased to 93%, 91%, and 93% respectively, in non-herniated discs. The MRS structure measures differed significantly between Pfirrmann grades, except grade I versus grade II. When all MRS positive discs were treated, surgical success was 97% versus 57% when the treated level was MRS negative, or 54% when the non-treated adjacent level was MRS positive. CONCLUSION: MRS correlates with PD and may support improved surgical outcomes for CLBP patients. Noninvasive MRS is a potentially valuable approach to clarifying pain mechanisms and designing CLBP therapies that are customized to the patient. These slides can be retrieved under Electronic Supplementary Material.

One-Level Versus 2-Level Treatment With Cervical Disc Arthroplasty or Fusion: Outcomes Up to 7 Years.

BACKGROUND: Anterior cervical discectomy and fusion (ACDF) and cervical disc arthroplasty (CDA) have been used to treat degenerative disc disease at single as well as multiple cervical levels. This study compares the safety and efficacy of 1-level versus 2-level CDA and ACDF. METHODS: In total, 545 and 397 patients with degenerative disc disease were studied in 1-level and 2-level Food and Drug Administration (FDA)-approved clinical trials, respectively: CDA (n = 280 and 209), ACDF (n = 265 and 188). Data from these studies were used to compare 1- versus 2-level procedures: the propensity score method was used to adjust for potential confounding effects, and adjusted mean outcome safety and efficacy scores at 2 and 7 years postsurgery were compared between 1-level and 2-level procedures within treatment type. RESULTS: One-level and 2-level procedures had similar rates of improvement in overall success and patient-reported outcomes scores for both CDA and ACDF. There were no statistical differences in rates of implant-related adverse events (AEs) or serious implant-related AEs between 1-level and 2-level CDA. The 7-year rate of implant-related AEs was higher for 2-level than 1-level ACDF (27.7% vs 18.9%, P ≤ .036), though the rates of serious implant-related AEs between ACDF groups did not differ significantly. Secondary surgery rates were not statistically different between 1-level and 2-level procedures (CDA or ACDF) at the index or adjacent levels at 2 or 7 years. Grade IV heterotopic ossification at 7 years was reported in 4.6% of 1-level CDA patients and 8.6%/7.3% at the superior/inferior levels, respectively, of 2-level CDA patients. CONCLUSIONS: One- and 2-level CDA appear equally safe and effective in the treatment of cervical degenerative disc disease. Two-level ACDF appears to be as effective as 1-level ACDF but with a higher rate of some AEs at long-term follow-up. LEVEL OF EVIDENCE: 2. CLINICAL TRIALS: clinicaltrials.gov: NCT00667459, NCT00642876, and NCT00637156.

Safety and Efficiency of Cervical Disc Arthroplasty in Ambulatory Surgery Centers vs. Hospital Settings.

BACKGROUND: Outpatient surgery has been shown safe and effective for anterior cervical discectomy and fusion (ACDF), and more recently, for 1-level cervical disc arthroplasty (CDA). The purpose of this analysis is to compare the safety and efficiency of 1-level and 2-level CDA performed in an ambulatory surgery center (ASC) and in a hospital setting. METHODS: The study was a retrospective collection and analysis of data from consecutive CDA patients treated in ASCs compared to a historical control group of patients treated in hospital settings who were classified as outpatient (0 or 1-night stay) or inpatient (2 or more nights). Surgery time, blood loss, return to work, adverse events (AEs), and subsequent surgeries were compared. RESULTS: The sample consisted of 145 ASC patients, 348 hospital outpatients, and 65 hospital inpatients. A greater proportion of 2-level surgeries were performed in hospital than ASC. Surgery times were significantly shorter in ASCs than outpatient or inpatient 1-level (63.6 ± 21.6, 86.5 ± 35.8, and 116.7 ± 48.4 minutes, respectively) and 2-level (92.4 ± 37.3, 126.7 ± 43.8, and 140.3 ± 54.5 minutes, respectively) surgeries. Estimated blood loss was also significantly less in ASC than outpatient and inpatient 1-level (18.5 ± 30.6, 43.7 ± 35.9, and 85.7 ± 98.0 mL, respectively) and 2-level (21.1 ± 12.3, 67.8 ± 94.9, and 64.9 ± 66.1 mL). There were no hospital admissions and no subsequent surgeries among ASC patients. ASC patients had 1 AE (0.7%) and hospital patients had 10 AEs (2.4%). Working patients returned to work after a similar number of days off, but fewer ASC patients had returned to work by the end of the 90-day period. CONCLUSIONS: Both 1- and 2-level CDA may be performed safely in an ASC. Surgeries in ASCs are of shorter duration and performed with less blood loss without increased AEs.

Treatment of Cervical Myelopathy: Long-term Outcomes of Arthroplasty for Myelopathy Versus Radiculopathy, And Arthroplasty Versus Arthrodesis for Myelopathy.

STUDY DESIGN: Analysis of 2- and 7-year outcomes from a clinical trial comparing 2-level cervical disk arthroplasty (CDA) to anterior cervical discectomy and fusion (ACDF) in 287 patients with radiculopathy alone, and 110 patients with myelopathy alone or myelopathy with radiculopathy. OBJECTIVE: To compare the long-term safety and effectiveness of CDA for myelopathy versus radiculopathy. SUMMARY OF BACKGROUND DATA: CDA for myelopathy is safe and effective in short term. MATERIALS AND METHODS: We analyzed Neck Disability Index (NDI), neck/arm pain, SF-36, neurological status, adverse events (AEs), and secondary surgeries at index and adjacent levels. RESULTS: All groups improved significantly for NDI, neck/arm pain, and physical component summary (PCS) scores from preoperative to postoperative. CDA Myelopathy versus CDA Radiculopathy: 2- and 7-year improvements were not significantly different. The 7-year score improvements for CDA Myelopathy and CDA Radiculopathy were: NDI (37.8 vs. 35.8, P=0.352), neck pain (12.0 vs. 12.1, P=0.477), arm pain (11.6 vs. 9.6, P=0.480), and PCS (14.1 vs. 13.7, P=0.863). The 2 groups had similar proportions of patients who maintained or improved their neurological status (87.2% vs. 93.5%, P=0.218), similar rates of serious AEs (54.5% vs. 57.5%, P=0.291) and similar rates of secondary surgeries at index (3.7% vs. 4.4%, P=0.839) and adjacent levels (3.7% vs. 7.6%, P=0.367). CDA Myelopathy versus ACDF myelopathy: 2 and 7-year improvements were not significantly different. The 7-year CDA and ACDF score improvements were: NDI (37.8 vs. 31.1, P=0.147), neck pain (12.0 vs. 10.4, P=0.337), arm pain (11.6 vs. 11.4, P=0.791), and PCS (14.1 vs. 11.2, P=0.363). The 2 groups had statistically similar proportions who maintained or improved their neurological status (87.2% vs. 96.2%, P=0.409), statistically similar overall rates of secondary surgeries at the index levels (3.7% vs. 9.4%, P=0.374), and statistically similar rates of secondary surgeries at adjacent levels (3.7% vs. 15.4%, P=0.088). CDA group demonstrated lower rates of serious AEs than ACDF (54.5% vs. 65.9%, P=0.019). CONCLUSIONS: CDA for myelopathy is a safe and effective long-term treatment.

Comparison of Lumbar Total Disc Replacement With Surgical Spinal Fusion for the Treatment of Single-Level Degenerative Disc Disease: A Meta-Analysis of 5-Year Outcomes From Randomized Controlled Trials.

STUDY DESIGN: Meta-analysis. OBJECTIVES: To evaluate the long-term efficacy and safety of total disc replacement (TDR) compared with fusion in patients with functionally disabling chronic low back pain due to single-level lumbar degenerative disc disease (DDD) at 5 years. METHODS: PubMed and Cochrane Central Register of Controlled Trials databases were searched for randomized controlled trials reporting outcomes at 5 years for TDR compared with fusion in patients with single-level lumbar DDD. Outcomes included Oswestry Disability Index (ODI) success, back pain scores, reoperations, and patient satisfaction. All analyses were conducted using a random-effects model; analyses were reported as relative risk (RR) ratios and mean differences (MDs). Sensitivity analyses were conducted for different outcome definitions, high loss to follow-up, and high heterogeneity. RESULTS: The meta-analysis included 4 studies. TDR patients had a significantly greater likelihood of ODI success (RR 1.0912; 95% CI 1.0004, 1.1903) and patient satisfaction (RR 1.13; 95% CI 1.03, 1.24) and a significantly lower risk of reoperation (RR 0.52; 95% CI 0.35, 0.77) than fusion patients. There was no association with improvement in back pain scores whether patients received TDR or fusion (MD -2.79; 95% CI -8.09, 2.51). Most results were robust to sensitivity analyses. Results for ODI success and patient satisfaction were sensitive to different outcome definitions but remained in favor of TDR. CONCLUSIONS: TDR is an effective alternative to fusion for lumbar DDD. It offers several clinical advantages over the longer term that can benefit the patient and reduce health care burden, without additional safety consequences.

Assessment of health-related quality of life in spine treatment: conversion from SF-36 to VR-12.

BACKGROUND CONTEXT: Health-related quality-of-life outcomes have been collected with the Medical Outcomes Study (MOS) Short Form 36 (SF-36) survey. Boston University School of Public Health has developed algorithms for the conversion of SF-36 to Veterans RAND 12-Item Health Survey (VR-12) Physical Component Summary (PCS) and Mental Component Summary (MCS) scores. PURPOSE: The purpose of the present study is to investigate the conversion of the SF-36 to VR-12 PCS and MCS scores. STUDY DESIGN: Preoperative and postoperative SF-36 were collected from patients who underwent lumbar or cervical surgery from a single surgeon between August 1998 and January 2013. METHODS: Short Form 36 PCS and MCS scores were calculated following their original instructions. The SF-36 answers were then converted to VR-12 PCS and MCS scores following the algorithm provided by the Boston University School of Public Health. The mean score, preoperative to postoperative change, and proportions of patients who reach the minimum detectable change were compared between SF-36 and VR-12. RESULTS: A total of 1,968 patients (1,559 lumbar and 409 cervical) had completed preoperative and postoperative SF-36. The values of the SF-36 and VR-12 mean scores were extremely similar, with score differences ranging from 0.77 to 1.82. The preoperative to postoperative improvement was highly significant (p<.001) for both SF-36 and VR-12 scores. The mean change scores were similar, with a difference of up to 0.93 for PCS and up to 0.37 for MCS. Minimum detectable change (MDC) values were almost identical for SF-36 and VR-12, with a difference of 0.12 for PCS and up to 0.41 for MCS. The proportions of patients whose change in score reached MDC were also nearly identical for SF-36 and VR-12. About 90% of the patients above SF-36 MDC were also above VR-12 MDC. CONCLUSIONS: The converted VR-12 scores, similar to the SF-36 scores, detect a significant postoperative improvement in PCS and MCS scores. The calculated MDC values and the proportions of patients whose score improvement reach MDC are similar for both SF-36 and VR-12.

Serum Metal Concentrations in Patients With Titanium Ceramic Composite Cervical Disc Replacements.

STUDY DESIGN: Prospective longitudinal study. OBJECTIVE: The serum titanium (Ti) concentrations were examined in patients implanted with a PRESTIGE LP Cervical Disc System (Medtronic, Inc., Memphis, TN). The metal-on-metal disc with ball-in-trough articulation is made of titanium alloy/titanium carbide composite (Ti-6Al-4 V/TiC). SUMMARY OF BACKGROUND DATA: Cervical disc arthroplasty provides a motion-preserving treatment alternative to anterior cervical discectomy and fusion for degenerative cervical disc disease. The articulating surfaces have a tendency to generate in vivo wear in the form of insoluble particulates (debris) and soluble metal ions. Not much information is available on the long-term metal concentrations observed in cervical disc arthroplasty and how these compare with the metal concentrations in Ti-based posterior fixation devices and other joint replacement implants. METHODS: Thirty patients were enrolled after strict exclusion criteria that included no previous permanent metal implants and no professional exposure to metal particles. High-resolution inductively coupled plasma-mass spectrometry was used to assay blood serum titanium concentrations preoperatively and at 3, 6, 12, 24, 36, 60, and 84 months after surgery. The detection limit for Ti was 0.2 ng/mL. The Friedman test was used to make longitudinal statistical comparisons. RESULTS: The median serum Ti concentrations determined preoperatively, and at 3, 6, 12, 24, 36, 60, and 84 months were 0.10, 1.22, 1.15, 1.27, 1.21, 1.46, 1.34, and 1.42 ng/mL, respectively. The serum Ti concentrations at all postoperative time points were significantly higher than that at the preoperative time point (Friedman P < 0.01). CONCLUSION: The long-term postoperative serum Ti concentrations were significantly higher than the preoperative concentrations. The observed serum Ti concentrations in this study are lower than the reported concentrations in patients receiving posterior spinal instrumentation and metal or ceramic-on-polyethylene hip prostheses with Ti-alloy based stems and acetabular components. LEVEL OF EVIDENCE: 3.

Observational Study of Depression in Patients Undergoing Cervical Disc Arthroplasty: Evidence of a Correlation between Pain Relief and Resolution of Depression.

BACKGROUND: Depression has been associated with inferior outcomes following lumbar spine surgery. Our purpose was to investigate the prevalence of depression and its impact on the outcomes of a large sample of cervical disc arthroplasty patients and to examine the change in depression occurring in conjunction with changes in disability and pain. METHODS: A cohort of 271 patients who underwent single or multi-level cervical disc arthroplasty at a single orthopedic center filled out the Neck Disability Index, Medical Outcomes Study SF-36, numerical rating scales for neck pain and arm pain, preoperatively and 12-month postoperatively. Patients were classified as Depressed or Non-Depressed, based on their preoperative SF-36 Mental Component Summary (MCS) score. Preoperative scores, 12-month postoperative scores, and change in scores (adjusted for preoperative scores, smoking status, and strenuous job) were compared between Depressed and Non-Depressed. Next, patients in the 2 groups were subdivided into 4 groups: Always Depressed, Never Depressed, No Longer Depressed, and Newly Depressed, based on their combined preoperative and postoperative MCS scores. The same score comparisons were conducted among the 4 groups. RESULTS: Forty-four percent (118 of 271) of the patients in our sample were Depressed. Despite a significant improvement after surgery, Depressed patients had poorer pre- and postoperative scores than Non-Depressed patients for NDI, MCS, neck pain and arm pain. Two-thirds (80 of 118) of the Depressed patients were No Longer Depressed at 12 months and had postoperative scores similar to the Never Depressed patients. Eight percent (12 of 153) of the Non-Depressed patients became Newly Depressed by 12 months and had postoperative scores similar to the Always Depressed patients. CONCLUSIONS: Depression is a common occurrence in patients with cervical disorders. Relief from pain and disability after cervical disc arthroplasty can be associated with relief from depression, but poor outcomes may also result in patients becoming depressed.

The Effect of Workers' Compensation Status on Outcomes of Cervical Disc Arthroplasty: A Prospective, Comparative, Observational Study.

BACKGROUND: Receiving Workers' Compensation benefits has been associated with inferior outcomes after lumbar fusion. The purpose of our study was to compare the outcomes of cervical disc arthroplasty between patients receiving and those not receiving Workers' Compensation. METHODS: Patient-reported outcomes, reoperations, complications, and return-to-work status were analyzed at one year after surgery in an observational cohort of consecutive patients who underwent single-level or multilevel cervical disc arthroplasty for symptomatic cervical disc conditions, including radiculopathy or discogenic pain with or without radiculopathy, exclusive of myelopathy. RESULTS: Of the 189 patients who underwent cervical disc arthroplasty, 144 received Workers' Compensation and forty-five did not. The mean scores on all patient-reported measures improved significantly from preoperative baseline to one year after surgery (p < 0.001), and the improvement in patient-reported outcomes did not differ significantly between the Workers' Compensation and the non-Workers' Compensation group (respectively, 22.7 compared with 25.0 for the Neck Disability Index; 8.3 compared with 9.6 for the Short Form (SF)-36 physical component summary; 7.9 compared with 9.6 for the SF-36 mental component summary; 3.5 compared with 3.7 for neck pain; and 2.6 compared with 2.8 for arm pain). The two groups also did not differ significantly in the rate of reoperations (7.6% for those receiving Workers' Compensation compared with 13.3% for those not receiving Workers' Compensation) and complications (2.8% compared with 4.4%, respectively). At one year after surgery, the proportion of patients who had returned to work was comparable (77.7% in the Workers' Compensation group and 79.4% in the non-Workers' Compensation group); however, the patients receiving Workers' Compensation had significantly more days off before returning to work (a mean of 145.2 compared with 61.9 days; p = 0.001). CONCLUSIONS: After cervical disc arthroplasty, patients receiving Workers' Compensation had outcomes that were similar to those of patients not receiving Workers' Compensation in terms of patient-reported outcomes, surgery-related complications, reoperations, and return-to-work status. Patients receiving Workers' Compensation remained off work for a longer interval than did patients not receiving Workers' Compensation. LEVEL OF EVIDENCE: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.