Search

Background Multiple studies describe the outcomes of patients undergoing single-level and multilevel posterolateral lumbar fusion (PLF). However, a comparison of outcomes between single-level and two-level PLF is lacking. The aim of this prospective cohort study was to compare outcomes between single-level and two-level instrumented PLF. Methods A total of 42 patients were enrolled at nine US centers between October 2015 and June 2017. Data included radiologic outcomes, visual analog scale (VAS) Back and Leg Pain, disability per the Oswestry Disability Index (ODI), and health-related quality of life (QoL) per 36-Item Short Form Survey version 2.0 (SF-36v2) at six weeks and three, six, 12, and 24 months. Results Twelve-month and 24-month follow-ups were completed by 38 (90.5%) and 32 (76.2%) subjects, respectively. The average age was 67 years, and 54.8% were female. Twenty-six received single-level PLF, and 16 received two-level PLF. In the single-level group, there was one reoperation, two postoperative infections, and one dural tear. In the two-level group, there was one postoperative infection. The surgeon computed tomography (CT)-based evaluation of fusion rate was 67.6% (25/37) at 12-month follow-up and 94.1% (32/34) at 24-month follow-up. The third-party evaluation of fusion rate was 52.8% (19/36) at six months, 81.1% (30/37) at 12 months, and 86.5% (32/37) at 24 months. There was a tendency toward a higher fusion rate in single-level compared with two-level PLF. The ODI, SF-36v2 Mental Component Score (MCS), and VAS Back Pain and Leg Pain outcomes improved by the first follow-up visit in both the single-level and two-level groups. Improvement in the ODI was 5.86 (95% confidence interval (CI): 0.03-11.69) points greater in the single-level group compared with the two-level group. Conclusions Compared with the two-level PLF subjects, single-level PLF subjects had better functional outcomes and reported higher satisfaction with the outcome of surgery but showed similar fusion, pain, and generic health-related quality of life outcomes. Both single-level and two-level PLF subjects demonstrated high fusion rates in association with improvements in pain, functional, and quality of life outcomes, as well as high satisfaction levels.

Aims To investigate the effect of polyethylene manufacturing characteristics and irradiation dose on the survival of cemented and reverse hybrid total hip arthroplasties (THAs). Methods In this registry study, data from the National Joint Registry of England, Wales, Northern Ireland and the Isle of Man (NJR) were linked with manufacturing data supplied by manufacturers. The primary endpoint was revision of any component. Cox proportional hazard regression was a primary analytic approach adjusting for competing risk of death, patient characteristics, head composition, and stem fixation. Results A total of 290,770 primary THAs were successfully linked with manufacturing characteristics. Overall 4,708 revisions were analyzed, 1,260 of which were due to aseptic loosening. Total radiation dose was identified as a risk factor and included in the Cox model. For statistical modelling of aseptic loosening, THAs were grouped into three categories: G1 (no radiation); G2 ( > 0 to < 5 Mrad); and G3 ( ≥ 5 Mrad). G1 had the worst survivorship. The Cox regression hazard ratio for revision due to aseptic loosening for G2 was 0.7 (95% confidence interval (CI) 0.58 to 0.83), and for G3 0.4 (95% CI 0.30 to 0.53). Male sex and uncemented stem fixation were associated with higher risk of revision and ceramic heads with lower risk. Conclusion Polyethylene irradiation was associated with reduced risk of revision for aseptic loosening. Radiation doses of ≥ 5 Mrad were associated with a further reduction in risk. Cite this article: Bone Joint Res 2020;9(9):563–571.

Study Design: Secondary analysis of data from the multicenter, randomized, parallel-controlled Food and Drug Administration (FDA) investigational device exemption study. Objective: Studies on outcomes following anterior cervical discectomy and fusion (ACDF) in individuals with diabetes are scarce. We compared 24-month radiological and clinical outcomes in individuals with and without diabetes undergoing single-level ACDF with either i-FACTOR or local autologous bone. Methods: Between 2006 and 2013, 319 individuals with single-level degenerative disc disease (DDD) and no previous fusion at the index level underwent ACDF. The presence of diabetes determined the 2 cohorts. Data collected included radiological fusion evaluation, neurological outcomes, Neck Disability Index (NDI), Visual Analog Scale (VAS) scores, and the 36-Item Short Form Survey Version 2 (SF-36v2) Physical and Mental component summary scores. Results: There were 35 individuals with diabetes (11.1%; average body mass index [BMI] = 32.99 kg/m2; SD = 5.72) and 284 without (average BMI = 28.32 kg/m2; SD = 5.67). The number of nondiabetic smokers was significantly higher than diabetic smokers: 73 (25.70%) and 3 (8.57%), respectively. Preoperative scores of NDI, VAS arm pain, and SF-36v2 were similar between the diabetic and nondiabetic participants at baseline; however, VAS neck pain differed significantly between the cohorts at baseline ( P = .0089). Maximum improvement for NDI, VAS neck and arm pain, and SF-36v2 PCS and MCS scores was seen at 6 months in both cohorts and remained stable until 24 months. Conclusions: ACDF is effective for cervical radiculopathy in patients with diabetes. Diabetes is not a contraindication for patients requiring single-level surgery for cervical DDD.

Aims The aim of this study was to identify the effect of the manufacturing characteristics of polyethylene acetabular liners on the survival of cementless and hybrid total hip arthroplasty (THA). Methods Prospective cohort study using linked National Joint Registry (NJR) and manufacturer data. The primary endpoint was revision for aseptic loosening. Cox proportional hazard regression was the primary analytical approach. Manufacturing variables included resin type, crosslinking radiation dose, terminal sterilization method, terminal sterilization radiation dose, stabilization treatment, total radiation dose, packaging, and face asymmetry. Total radiation dose was further divided into G1 (no radiation), G2 (> 0 Mrad to < 5 Mrad), G3 (≥ 5 Mrad to < 10 Mrad), and G4 (≥ 10 Mrad). Results A total of 5,329 THAs were revised, 1,290 of which were due to aseptic loosening. Total radiation dose, face asymmetry, and stabilization treatments were found to significantly affect implant survival. G1 had the highest revision risk for any reason and for aseptic loosening and G3 and G4 the lowest. Compared with G1, the adjusted hazard ratio for G2 was 0.74 (95% confidence interval (CI) 0.64 to 0.86), G3 was 0.36 (95% CI 0.30 to 0.43), and G4 was 0.38 (95% CI 0.31 to 0.47). The cumulative incidence of revision for aseptic loosening at 12 years was 0.52 and 0.54 per 100 THAs for G3 and G4, respectively, compared with 1.95 per 100 THAs in G1. Asymmetrical liners had a lower revision risk due to aseptic loosening and reasons other than aseptic loosening compared with symmetric (flat) liners. In G3 and G4, stabilization with vitamin E and heating above melting point performed best. Conclusion Polyethylene liners with a total radiation dose of ≥ 5 Mrad, an asymmetrical liner face, and stabilization with heating above the melting point demonstrate best survival. Cite this article: Bone Joint J 2020;102-B(1):90–101

Aims The aim of our study was to investigate the effect of asymmetric crosslinked polyethylene liner use on the risk of revision of cementless and hybrid total hip arthroplasties (THAs). Methods We undertook a registry study combining the National Joint Registry dataset with polyethylene manufacturing characteristics as supplied by the manufacturers. The primary endpoint was revision for any reason. We performed further analyses on other reasons including instability, aseptic loosening, wear, and liner dissociation. The primary analytic approach was Cox proportional hazard regression. Results A total of 213,146 THAs were included in the analysis. Overall, 2,997 revisions were recorded, 1,569 in THAs with a flat liner and 1,428 in THAs using an asymmetric liner. Flat liner THAs had a higher risk of revision for any reason than asymmetric liner THAs when implanted through a Hardinge/anterolateral approach (hazard ratio (HR) 1.169, 95% confidence interval (CI) 1.022 to 1.337) and through a posterior approach (HR 1.122, 95% CI 1.108 to 1.346). There was no increased risk of revision for aseptic loosening when asymmetric liners were used for any surgical approach. A separate analysis of the three most frequently used crosslinked polyethylene liners was in agreement with this finding. When analyzing THAs with flat liners only, THAs implanted through a Hardinge/anterolateral approach were associated with a reduced risk of revision for instability compared to posterior approach THAs (HR 0.561 (95% CI 0.446 to 0.706)). When analyzing THAs with an asymmetric liner, there was no significant difference in the risk of revision for instability between the two approaches (HR 0.838 (95% CI 0.633 to 1.110)). Conclusion For THAs implanted through the posterior approach, the use of asymmetric liners reduces the risk of revision for instability and revision for any reason. In THAs implanted through a Hardinge/anterolateral approach, the use of an asymmetric liner was associated with a reduced risk of revision. The effect on revision for instability was less pronounced than in the posterior approach. Cite this article: Bone Joint J 2021;103-B(9):1479–1487.

Background Preoperative duration of symptoms may significantly impact outcomes in patients treated surgically for degenerative cervical myelopathy (DCM). Objective To (i) analyze whether duration of symptoms is associated with preoperative functional impairment, disability, and quality of life and (ii) determine the optimal timing for decompressive surgery. Methods Patients with DCM were prospectively enrolled in either the AOSpine North American or International study at 26 global sites (n = 757). Postoperative functional impairment was evaluated at 1-yr using the modified Japanese Orthopaedic Association (mJOA) score. Change scores between baseline and 1-yr were computed for the mJOA. Duration of symptoms was dichotomized into a "short" and "long" group at several cut-offs. Analysis of covariance was used to evaluate differences in change scores on the mJOA between duration of symptoms groups in 4-mo increments. Results Our cohort consisted of 424 men and 255 women, with a mean duration of symptoms of 26.1 ± 36.4 mo (0.25-252 mo). Duration of symptoms was not correlated with preoperative mJOA, Nurick, Neck Disability Index, or Short-Form (SF)-36 Physical and Mental Component Scores. Patients with a duration of symptoms shorter than 4 mo had significantly better functional outcomes on the mJOA than patients with a longer duration of symptoms (>4 mo). Thirty-two months was also a significant cut-off. Conclusion Patients who are operated on within 4 mo of symptom presentation have better mJOA outcomes than those treated after 4 mo. It is recommended that patients with DCM are diagnosed in a timely fashion and managed appropriately.

Background Whilst bony fixation of hip replacement has stable solutions, there remains controversy over which bearing best optimizes longevity and function. Ceramic-on-ceramic (CoC) bearing combinations are associated with lower risk of revision due to aseptic loosening and dislocation. Evidence for long-term functional outcomes of modern, 4th generation CoC bearings is limited. The aim of this study was to analyze outcomes and complications of the R3™ Acetabular System (Smith & Nephew, Inc., Cordova, TN, USA) in combination with BIOLOX® Delta ceramic femoral head in patients undergoing primary total hip arthroplasty (THA). Methods Between June 2009 and May 2011, 175 patients (178 hips) were enrolled into a prospective, study at 6 sites in Europe and prospectively followed-up at 3 months and 1, 3, 5, and 7 years postoperative. Results Total WOMAC score improved from 63 (range, 22–91) preoperative to 8 (range, 0–8) at 1-year follow-up and remained unchanged at 7-year follow-up. Modified Harris hip score improved from 45 (range, 10–87) preoperative to 83 (range, 25–100) at 3 months, 91 (range, 42–100) at 1 year, and 92 (range, 46, 100) at 7 years. UCLA Activity Rating Scale score improved from 3.3 (range, 1–8) preoperative to 6.2 (range, 2–8) at 1 year; it marginally declined to 5.8 (range, 3–8) at 7-year follow-up. There were 4 trochanteric fractures and 5 patients died of unrelated reasons. Three hips were revised (2 periprosthetic fractures and 1 subluxation). The 7-year cumulative survival rate was 98.3%. Conclusion Clinical and functional improvements of THA with CoC bearing are maintained at 7 years postoperative. Trial registration ClinicalTrials.Gov, NCT03566082, Registered 10 January 2018—retrospectively registered

Background: Whilst bony fixation of hip replacement has stable solutions, there remains controversy over which bearing best optimizes longevity and function. Ceramic-on-ceramic (CoC) bearing combinations are associated with lower risk of revision due to aseptic loosening and dislocation. Evidence for long-term functional outcomes of modern, 4th generation CoC bearings is limited. The aim of this study was to analyze outcomes and complications of the R3™ Acetabular System (Smith & Nephew, Inc., Cordova, TN, USA) in combination with BIOLOX® Delta ceramic femoral head in patients undergoing primary total hip arthroplasty (THA).Methods: Between June 2009 and May 2011, 175 patients (178 hips) were enrolled into a prospective, study at 6 sites in Europe and prospectively followed-up at 3 months and 1, 3, 5, and 7 years postoperative. Results: Total WOMAC score improved from 63 (range, 22-91) preoperative to 8 (range, 0- 8) at 1-year follow-up and remained unchanged at 7-year follow-up. Modified Harris Hip Score improved from 45 (range, 10-87) preoperative to 83 (range, 25-100) at 3 months, 91 (range, 42-100) at 1 year, and 92 (range, 46, 100) at 7 years. UCLA Activity Rating Scale score improved from 3.3 (range, 1-8) preoperative to 6.2 (range, 2-8) at 1 year; it marginally declined to 5.8 (range, 3-8) at 7-year follow-up. There were 4 trochanteric fractures and 5 patients died of unrelated reasons. Three hips were revised (2 periprosthetic fractures and 1 subluxation). The 7-year cumulative survival rate was 98.3%. Conclusion: Clinical and functional improvements of THA with CoC bearing are maintained at 7 years postoperative.

Summary Background Degenerative cervical myelopathy represents the most common form of non-traumatic spinal cord injury. This trial investigated whether riluzole enhances outcomes in patients undergoing decompression surgery for degenerative cervical myelopathy. Methods This multicentre, double-blind, placebo-controlled, randomised, phase 3 trial was done at 16 university-affiliated centres in Canada and the USA. Patients with moderate-to-severe degenerative cervical myelopathy aged 18–80 years, who had a modified Japanese Orthopaedic Association (mJOA) score of 8–14, were eligible. Patients were randomly assigned (1:1) to receive either oral riluzole (50 mg twice a day for 14 days before surgery and then for 28 days after surgery) or placebo. Randomisation was done using permuted blocks stratified by study site. Patients, physicians, and outcome assessors remained masked to treatment group allocation. The primary endpoint was change in mJOA score from baseline to 6 months in the intention-to-treat (ITT) population, defined as all individuals who underwent randomisation and surgical decompression. Adverse events were analysed in the modified intention-to-treat (mITT) population, defined as all patients who underwent randomisation, including those who did not ultimately undergo surgical decompression. This study is registered with ClinicalTrials.gov , NCT01257828 . Findings From Jan 31, 2012, to May 16, 2017, 408 patients were screened. Of those screened, 300 were eligible (mITT population); 290 patients underwent decompression surgery (ITT population) and received either riluzole (n=141) or placebo (n=149). There was no difference between the riluzole and placebo groups in the primary endpoint of change in mJOA score at 6-month follow-up: 2·45 points (95% CI 2·08 to 2·82 points) versus 2·83 points (2·47 to 3·19), difference −0·38 points (−0·90 to 0·13; p=0·14). The most common adverse events were neck or arm or shoulder pain, arm paraesthesia, dysphagia, and worsening of myelopathy. There were 43 serious adverse events in 33 (22%) of 147 patients in the riluzole group and 34 serious adverse events in 29 (19%) of 153 patients in the placebo group. The most frequent severe adverse events were osteoarthrosis of non-spinal joints, worsening of myelopathy, and wound complications. Interpretation In this trial, adjuvant treatment for 6 weeks perioperatively with riluzole did not improve functional recovery beyond decompressive surgery in patients with moderate-to-severe degenerative cervical myelopathy. Whether riluzole has other benefits in this patient population merits further study. Funding AOSpine North America.

The aim of this study was to identify the effect of the manufacturing characteristics of polyethylene acetabular liners on the survival of cementless and hybrid total hip arthroplasty (THA).Prospective cohort study using linked National Joint Registry (NJR) and manufacturer data. The primary endpoint was revision for aseptic loosening. Cox proportional hazard regression was the primary analytical approach. Manufacturing variables included resin type, crosslinking radiation dose, terminal sterilization method, terminal sterilization radiation dose, stabilization treatment, total radiation dose, packaging, and face asymmetry. Total radiation dose was further divided into G1 (no radiation), G2 (0 Mrad to5 Mrad), G3 (≥ 5 Mrad to10 Mrad), and G4 (≥ 10 Mrad).A total of 5,329 THAs were revised, 1,290 of which were due to aseptic loosening. Total radiation dose, face asymmetry, and stabilization treatments were found to significantly affect implant survival. G1 had the highest revision risk for any reason and for aseptic loosening and G3 and G4 the lowest. Compared with G1, the adjusted hazard ratio for G2 was 0.74 (95% confidence interval (CI) 0.64 to 0.86), G3 was 0.36 (95% CI 0.30 to 0.43), and G4 was 0.38 (95% CI 0.31 to 0.47). The cumulative incidence of revision for aseptic loosening at 12 years was 0.52 and 0.54 per 100 THAs for G3 and G4, respectively, compared with 1.95 per 100 THAs in G1. Asymmetrical liners had a lower revision risk due to aseptic loosening and reasons other than aseptic loosening compared with symmetric (flat) liners. In G3 and G4, stabilization with vitamin E and heating above melting point performed best.Polyethylene liners with a total radiation dose of ≥ 5 Mrad, an asymmetrical liner face, and stabilization with heating above the melting point demonstrate best survival. Cite this article

Introduction Total knee arthroplasty (TKA) can provide pain relief and good long-term results. However, nearly 30% of post-surgical patients are unsatisfied due to persistent pain and functional deficits. A second-generation bi-cruciate stabilized TKA device has a post-cam mechanism with an asymmetric femoral component, a polyethylene insert, and a medially concave and laterally convex shape. The device is designed to provide guided motion, and thus improve knee kinematics by more closely approximating a normal knee. The aim of this study was to evaluate early complication and revision rates of the second-generation device and to compare its clinical performance to the first-generation device. Materials and methods In this retrospective, longitudinal, non-concurrent cohort study, 140 TKAs were performed using the second-generation device on 131 patients from 2012 to 2016, and 155 TKAs were performed using the first-generation device on 138 patients from 2009 to 2012. Primary outcomes were occurrence of revisions and reoperations. Results There were 31 reoperations [3.21 per 100 observed component years (OCY)] in 22 (2.28 per 100 OCY) TKAs in the first-generation device cohort compared to five reoperations (1.92 per 100 OCY) in four TKAs (1.54 per 100 OCY) in the second-generation device cohort. The adjusted hazard ratio (HR) was 3.50 (P = 0.0254). There were 21 revisions (2.17 per 100 OCY) in 16 (1.66 per 100 OCY) TKAs in the first-generation device cohort, compared to only three revisions (1.15 per 100 OCY) in two TKAs (0.77 per 100 OCY) in the second-generation device cohort. The adjusted HR was 4.16 (P = 0.0693). Conclusion The improved design of the second-generation device appears to be associated with a lower risk of reoperation and revision compared to that of the first-generation device. Level of evidence III.

BACKGROUND This study was designed to identify preoperative predictors of survival in surgically treated patients with metastatic epidural spinal cord compression (MESCC), to examine how these predictors are related to 8 prognostic models, and to perform the first full external validation of these models in accordance with the Transparent Reporting of a Multivariable Prediction Model for Individual Prognosis or Diagnosis (TRIPOD) statement. METHODS One hundred forty-two surgically treated patients with MESCC were enrolled in a prospective, multicenter North American cohort study and were followed for 12 months or until death. Cox regression was used. Noncollinear predictors with

Degenerative cervical myelopathy (DCM) is a progressive degenerative spine disease and the most common cause of spinal cord impairment in adults worldwide. Few studies have reported on regional variations in demographics, clinical presentation, disease causation, and surgical effectiveness.The objective of this study was to evaluate differences in demographics, causative pathology, management strategies, surgical outcomes, length of hospital stay, and complications across four geographic regions.This is a multicenter international prospective cohort study.This study includes a total of 757 symptomatic patients with DCM undergoing surgical decompression of the cervical spine.The outcome measures are the Neck Disability Index (NDI), the Short Form 36 version 2 (SF-36v2), the modified Japanese Orthopaedic Association (mJOA) scale, and the Nurick grade.The baseline characteristics, disease causation, surgical approaches, and outcomes at 12 and 24 months were compared among four regions: Europe, Asia Pacific, Latin America, and North America.Patients from Europe and North America were, on average, older than those from Latin America and Asia Pacific (p=.0055). Patients from Latin America had a significantly longer duration of symptoms than those from the other three regions (p.0001). The most frequent causes of myelopathy were spondylosis and disc herniation. Ossification of the posterior longitudinal ligament was most prevalent in Asia Pacific (35.33%) and in Europe (31.75%), and hypertrophy of the ligamentum flavum was most prevalent in Latin America (61.25%). Surgical approaches varied by region; the majority of cases in Europe (71.43%), Asia Pacific (60.67%), and North America (59.10%) were managed anteriorly, whereas the posterior approach was more common in Latin America (66.25%). At the 24-month follow-up, patients from North America and Asia Pacific exhibited greater improvements in mJOA and Nurick scores than those from Europe and Latin America. Patients from Asia Pacific and Latin America demonstrated the most improvement on the NDI and SF-36v2 PCS. The longest duration of hospital stay was in Asia Pacific (14.16 days), and the highest rate of complications (34.9%) was reported in Europe.Regional differences in demographics, causation, and surgical approaches are significant for patients with DCM. Despite these variations, surgical decompression for DCM appears effective in all regions. Observed differences in the extent of postoperative improvements among the regions should encourage the standardization of care across centers and the development of international guidelines for the management of DCM.

BACKGROUND CONTEXT 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. PURPOSE We report 6-year clinical and radiological outcomes of post-approval study. STUDY DESIGN/SETTING 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. PATIENT SAMPLE 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. OUTCOME MEASURES Radiological, clinical, and patient-reported outcomes. METHODS 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. RESULTS 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. CONCLUSIONS 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. FDA DEVICE/DRUG STATUS I-Factor (Approved for this indication)

Background i-Factor™ Bone Graft (Cerapedics Inc, Westminster, Colorado) is a composite bone substitute material consisting of P-15 synthetic collagen fragment adsorbed onto anorganic bone mineral suspended in an inert biocompatible hydrogel carrier. A pivotal, noninferiority, US FDA Investigational Device Exemption study demonstrated the benefits of i-Factor™ compared to local autograft bone in single-level anterior cervical discectomy and fusion at 1-yr postoperative. Objective To report 2-yr follow-up. Methods Subjects randomly received either autograft (n = 154) or i-Factor™ (n = 165) in a cortical ring allograft and followed using radiological, clinical, and patient-reported outcomes. Results At 2 yr, the fusion rate was 97.30% and 94.44% in i-Factor™ and autograft subjects, respectively (P = .2513), and neurological success rate was 94.87% (i-Factor™) and 93.79% (autograft; P = .7869). Neck Disability Index improved 28.30 (i-Factor™) and 26.95 (autograft; P = .1448); Visual Analog Scale arm pain improved 5.43 (i-Factor™) and 4.97 (autograft) (p = .2763); Visual Analog Scale neck pain improved 4.78 (i-Factor™) and 4.41 (autograft; P = .1652), Short Form-36 (SF-36v2) Physical Component Score improved 10.23 (i-Factor™) and 10.18 (autograft; P = .4507), and SF36v2 Mental Component Score improved 7.88 (i-FactorTM) and 7.53 (autograft; P = .9872). The composite endpoint of overall success (fusion, Neck Disability Index improvement >15, neurological success, and absence of re-operations) was greater in i-Factor™ subjects compared to autograft subjects (69.83% and 56.35%, respectively, P = .0302). Twelve (7.45%) i-Factor™ subjects and 16 (10.53%) autograft subjects underwent re-operation (P = .3411). There were no allergic reactions associated with i-Factor™. Conclusion Use of i-Factor™ in anterior cervical discectomy and fusion is effective and safe, and results in similar outcomes compared to local autograft bone at 2 yr following surgery.

Study design Analysis of a combined prospective dataset. Objective To compare clinical outcomes in patients with and without preexisting depression or bipolar disorder undergoing surgery for degenerative cervical myelopathy (DCM). Summary of background data Psychiatric comorbidities, including depression, have been associated with worse clinical outcomes after lumbar spine surgery; however, it is unclear whether these psychiatric disorders are also predictive of outcomes in patients undergoing surgery for the treatment of DCM. Methods Four hundred and one patients with symptomatic DCM were enrolled in the prospective AOSpine International or North America study at twelve North American sites. Patients were evaluated preoperatively and at 6, 12, and 24 months using the modified Japanese Orthopedic Association scale (mJOA), Nurick score, Neck Disability Index (NDI), and Short- Form 36v2 (SF-36v2) Health Survey. A mixed model analytic approach was used to evaluate differences in outcomes at 24 months among patients with and without psychiatric disorders, while controlling for relevant baseline characteristics and surgical factors. Results Ninety-seven patients (24.19%) were diagnosed with preexisting depression or bipolar disorder. There were more females (65.98%) with these psychiatric disorders than males (34.02%) (P Conclusion Patients with depression or bipolar disorder have smaller functional and quality of life improvements after surgery compared to patients without psychiatric comorbidities. Level of evidence 2.

Degenerative cervical myelopathy (DCM) represents the most common cause of non-traumatic spinal cord impairment in adults. Surgery has been shown to improve neurologic symptoms and functional status, but it is costly. As sustainability concerns in the field of health care rise, the value of care has come to the forefront of policy decision-making. Evidence for both health-related quality of life outcomes and financial expenditures is needed to inform resource allocation decisions.This study aimed to estimate the lifetime incremental cost-utility of surgical treatment for DCM.This is a prospective observational cohort study at a Canadian tertiary care facility.We recruited all patients undergoing surgery for DCM at a single center between 2005 and 2011 who were enrolled in either the AOSpine Cervical Spondylotic Myelopathy (CSM)-North America study or the AOSpine CSM-International study.Health utility was measured at baseline and at 6, 12, and 24 months following surgery using the Short Form-6D (SF-6D) health utility score. Resource expenditures were calculated on an individual level, from the hospital payer perspective over the 24-month follow-up period. All costs were obtained from a micro-cost database maintained by the institutional finance department and reported in Canadian dollars, inflated to January 2015 values.Quality-adjusted life year (QALY) gains for the study period were determined using an area under the curve calculation with a linear interpolation estimate. Lifetime incremental cost-to-utility ratios (ICUR) for surgery were estimated using a Markov state transition model. Structural uncertainty arising from lifetime extrapolation and the single-arm cohort design of the study were accounted for by constructing two models. The first included a highly conservative assumption that individuals undergoing nonoperative management would not experience any lifetime neurologic decline. This constraint was relaxed in the second model to permit more general parameters based on the established natural history. Deterministic and probabilistic sensitivity analyses were employed to account for parameter uncertainty. All QALY gains and costs were discounted at a base of 3% per annum. Statistical significance was set at the .05 level.The analysis included 171 patients; follow-up was 96.5%. Mean age was 58.2±12.0 years and baseline health utility was 0.56±0.14. Mean QALY gained over the 24-month study period was 0.139 (95% confidence interval: 0.109-0.170, p.001) and the mean 2-year cost of treatment was $19,217.82±12,404.23. Cost associated with the operation comprised 65.7% of the total. The remainder was apportioned over presurgical preparation and postsurgical recovery. Three patients required a reoperation over the 2-year follow-up period. The costs of revision surgery represented 1.85% of the total costs. Using the conservative model structure, the estimated lifetime ICUR of surgical intervention was $20,547.84/QALY gained, with 94.7% of estimates falling within the World Health Organization definition of "very cost-effective" ($54,000 CAD). Using the more general model structure, the estimated lifetime ICUR of surgical intervention was $11,496.02/QALY gained, with 97.9% of estimates meeting the criteria to be considered "very cost-effective."Surgery for DCM is associated with a significant quality of life improvement. The intervention is cost-effective and, from the perspective of the hospital payer, should be supported.

BACKGROUND: The JOURNEY II Bi-Cruciate Stabilizing Total Knee System (BLINDED) is a second-generation guided-motion knee implant that has been used in over 100,000 primary total knee arthroplasties (TKAs) worldwide. However, performance information is limited. METHODS: Data for 2059 primary TKAs were abstracted at 7 US and 3 European sites. Estimates of cumulative incidence of revision were compared with registry data for cemented posterior-stabilized implants. RESULTS: Average age was 64.3 years (range, 18-91); 58.5% were females; and 12.3% TKAs were in subjects younger than 55 years. Patellae were resurfaced in 95.9%. Median time since primary TKA was 4.2 years; longest was 6.1 years; and 78.9% were 3 years or more since primary TKA. Of 67 revisions (3.2%), 20 (30%) involved femoral or tibial component removal compared to 42% in the Australian Joint Registry (Australian Orthopedic Association National Joint Replacement Registry). All-component revisions accounted for 15 of 67, femoral component only for 2 of 67, tibial component only for 3 of 67, patellar component with/without tibial insert exchange for 17 of 67, and isolated tibial insert exchange for 30 of 67. In addition, there were 18 reoperations without component exchange. Component revision indications were infection (33%), mechanical loosening (21%), fracture of bone around the joint (16%), and instability (15%). Kaplan-Meier revision estimate was 3.1 and 3.6 per 100 TKAs at 3 and 5 years, respectively, compared to Australian Orthopedic Association National Joint Replacement Registry estimates of 3.1 and 4.1 per 100 TKAs. CONCLUSION: The revision rate for the second-generation implant was similar to cemented posterior-stabilized registry controls. ispartof: JOURNAL OF ARTHROPLASTY vol:34 issue:7 pages:S201-S208 ispartof: location:United States status: published

Background Surgery for cervical spondylotic myelopathy (CSM) is generally safe and effective. Nonetheless, complications occur in 11% to 38% of patients. Knowledge of important predictors of complications will help clinicians identify high-risk patients and institute prevention and management strategies. Objective To identify clinical and surgical predictors of perioperative complications in CSM patients. Methods Four hundred seventy-nine surgical CSM patients were enrolled in the prospective CSM-International study at 16 sites. A panel of physicians reviewed all adverse events and classified each as related or unrelated to surgery. Univariate analyses were performed to determine differences between patients who experienced a perioperative complication and those who did not. A complication prediction rule was developed using multiple logistic regression. Results Seventy-eight patients experienced 89 perioperative complications (16.25%). On univariate analysis, the major clinical risk factors were ossification of the posterior longitudinal ligament (OPLL) (P = .055), number of comorbidities (P = .002), comorbidity score (P = .006), diabetes mellitus (P = .001), and coexisting gastrointestinal (P = .039) and cardiovascular (P = .046) disorders. Patients undergoing a 2-stage surgery (P = .002) and those with a longer operative duration (P = .001) were at greater risk of perioperative complications. A final prediction model consisted of diabetes mellitus (odds ratio [OR] = 1.96, P = .060), number of comorbidities (OR = 1.20, P = .069), operative duration (OR = 1.07, P = .002), and OPLL (OR = 1.75, P = .040). Conclusion Surgical CSM patients have a higher risk of perioperative complications if they have a greater number of comorbidities, coexisting diabetes mellitus, OPLL, and a longer operative duration. Surgeons can use this information to discuss the risks and benefits of surgery with patients, to plan case-specific preventive strategies, and to ensure appropriate management in the perioperative period. Abbreviations BMI, body mass indexCSM, cervical spondylotic myelopathymJOA, modified Japanese Orthopaedic AssociationOPLL, ossification of the posterior longitudinal ligament.

STUDY DESIGN A prospective, randomized, controlled, parallel, single-blinded noninferiority multicenter pivotal FDA IDE trial. OBJECTIVE The objective of this study was to investigate efficacy and safety of i-Factor Bone Graft (i-Factor) compared with local autograft in single-level anterior cervical discectomy and fusion (ACDF) for cervical radiculopathy. SUMMARY OF BACKGROUND DATA i-Factor is a composite bone substitute material consisting of the P-15 synthetic collagen fragment adsorbed onto anorganic bone mineral and suspended in an inert biocompatible hydrogel carrier. P-15 has demonstrated bone healing efficacy in dental, orthopedic, and nonhuman applications. METHODS Patients randomly received either autograft (N = 154) or i-Factor (N = 165) in a cortical ring allograft. Study success was defined as noninferiority in fusion, Neck Disability Index (NDI), and Neurological Success endpoints, and similar adverse events profile at 12 months. RESULTS At 12 months (follow-up rate 87%), both i-Factor and autograft subjects demonstrated a high fusion rate (88.97% and 85.82%, respectively, noninferiority P = 0.0004), significant improvements in NDI (28.75 and 27.40, respectively, noninferiority P

Purpose Although surgery is used increasingly as a strategy to complement treatment with radiation and chemotherapy in patients with metastatic epidural spinal cord compression (MESCC), the impact of surgery on health-related quality of life (HRQoL) is not well established. We aimed to prospectively evaluate survival, neurologic, functional, and HRQoL outcomes in patients with MESCC who underwent surgical management. Patients and Methods One hundred forty-two patients with a single symptomatic MESCC lesion who were treated surgically were enrolled onto a prospective North American multicenter study and were observed at least up to 12 months. Clinical data, including Brief Pain Inventory, ASIA (American Spinal Injury Association) impairment scale, SF-36 Short Form Health Survey, Oswestry Disability Index, and EuroQol 5 dimensions (EQ-5D) scores, were obtained preoperatively, and at 6 weeks and 3, 6, 9, and 12 months postoperatively. Results Median survival time was 7.7 months. The 30-day and 12-month mortality rates were 9% and 62%, respectively. There was improvement at 6 months postoperatively for ambulatory status (McNemar test, P < .001), lower extremity and total motor scores (Wilcoxon signed rank test, P < .001), and at 6 weeks and 3, 6, and 12 months for Oswestry Disability Index, EQ-5D, and pain interference (paired t test, P < .013). Moreover, at 3 months after surgery, the ASIA impairment scale grade was improved (Stuart-Maxwell test P = .004). SF-36 scores improved postoperatively in six of eight scales. The incidence of wound complications was 10% and 2 patients required a second surgery (screw malposition and epidural hematoma). Conclusion Surgical intervention, as an adjunct to radiation and chemotherapy, provides immediate and sustained improvement in pain, neurologic, functional, and HRQoL outcomes, with acceptable risks in patients with a focal symptomatic MESCC lesion who have at least a 3 month survival prognosis.

Background: Cervical spondylotic myelopathy (CSM) is a progressive spinal condition that is often managed surgically. Knowledge of important predictors of surgical outcome can provide decision support to surgeons and enable them to effectively manage their patients’ expectations. The purpose of this study was to identify the most important clinical predictors of surgical outcome in patients with CSM using data from two multinational prospective studies. Methods: A total of 757 patients treated surgically for CSM participated in either the CSM-North America or the CSM-International study. The model was designed to distinguish between patients who achieved a modified Japanese Orthopaedic Association (mJOA) score of ≥16 at the one-year follow-up and those who did not (mJOA < 16). A score of 16 was chosen as the cutoff as an mJOA of ≥16 translates to minimal impairment. Univariate analyses evaluated the relationship between outcome and various clinical predictors. Multivariate Poisson regression was used to create the final prediction rule and estimate relative risks. Results: Based on univariate analyses, the probability of achieving a score of ≥16 decreased with the presence of certain symptoms, including gait dysfunction, the presence of certain signs such as lower limb spasticity, positive smoking status, higher comorbidity score, more severe preoperative myelopathy, and older age. The final model consisted of six significant and clinically relevant predictors: baseline severity score (relative risk [RR], 1.11; 95% confidence interval [CI], 1.07 to 1.15), impaired gait (RR, 0.76 [ref. = absence]; 95% CI, 0.66 to 0.88), age (RR, 0.91 per decade; 95% CI, 0.85 to 0.96), comorbidity score (RR, 0.93; 95% CI, 0.88 to 0.98), smoking status (RR, 0.78 [ref. = non-smoking]; 95% CI, 0.65 to 0.93), and duration of symptoms (RR, 0.95; 95% CI, 0.90 to 0.99). Conclusions: Patients were more likely to achieve a score of ≥16 (indicating minimal impairment) if they were younger, had milder preoperative myelopathy, did not smoke, had fewer and less severe comorbidities, did not present with impaired gait, and had shorter symptom duration. Level of Evidence: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Analysis of the prospective AOSpine CSM-International and North America datasets and survey of AO Spine International.This study aims to define the minimum clinically important difference (MCID) of the modified Japanese Orthopaedic Association (mJOA) in patients with degenerative cervical myelopathy (DCM).The mJOA is the most frequently used clinician-administered tool to assess functional status in patients with DCM. By defining its MCID, clinicians can better evaluate treatment outcomes for this condition.Three methods were used to determine the MCID of the mJOA: (1) distribution-based, (2) anchor-based and receiver operating characteristic (ROC) analysis, and (3) professional opinion. Distribution-based methods were used to estimate the MCID by computing the half standard deviation and standard error of measurement. Using anchor-based methods, mJOA at 12 months after surgery was compared between patients who were "slightly improved" on the Neck Disability Index (NDI) and those who were "unchanged." ROC analysis was performed to compute a discrete integer value for the MCID that yielded the smallest difference between sensitivity and specificity. We repeated anchor-based methods for patients with mild (mJOA: 15-17), moderate (mJOA: 12-14), and severe disease (mJOA12).The half standard deviation of the baseline mJOA was 1.36 and the standard error of measurement was 1.21. The difference in mJOA between patients who "slightly improved" on the NDI and "unchanged" patients was 1.11. ROC analysis yielded a value of 2 for the MCID. The survey of 416 spine professionals confirmed these estimates: the mean response was 1.65 ± 0.66. The MCID significantly varied depending on myelopathy severity: ROC analysis yielded a threshold of 1 for mild, 2 for moderate, and 3 for severe patients.The MCID of the mJOA is estimated to be between 1 and 2 points and varies with myelopathy severity. This knowledge will enable clinicians to identify meaningful functional improvements in DCM patients.N/A.

Background Modern bearing surface options have increased implant survivorship after total hip arthroplasty (THA). We utilized data from the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man (NJR) to analyze implant survivorship after THAs with uncemented acetabular components with different bearing combinations. Methods Polyethylene (PE) manufacturing properties supplied by the manufacturers were used to subdivide the NJR data set into cross-linked PE (XLPE) and conventional PE groups. Overall and cause-specific revisions for various bearing combinations were analyzed using Kaplan-Meier and multivariate Cox proportional hazard regression survival analyses. Results Of 420,339 primary THAs, 8,025 were revised during an average follow-up period of 4.4 years (maximum, 13.3 years). In the Cox regression model with metal on conventional PE as the reference, the lowest risk of revision for any reason was for ceramicized metal on XLPE (hazard ratio [HR] = 0.58, 95% confidence interval [CI] = 0.48, 0.71), followed by ceramic on XLPE (HR = 0.66, 95% CI = 0.60, 0.72), ceramic on PE (HR = 0.74, 95% CI = 0.66, 0.82), ceramic on ceramic (HR = 0.77, 95% CI = 0.72, 0.82), and metal on XLPE (HR = 0.81, 95% CI = 0.76, 0.87). A similar pattern was observed when patients under the age of 55 years were analyzed independently. Younger age, male sex, and cementless stem fixation were associated with a higher risk of revision. Conclusions In a fully adjusted model, ceramicized metal on XLPE and ceramic on XLPE were associated with the lowest risk of revision for any reason. This finding was sustained when patients under the age of 55 years were analyzed independently. On the basis of the NJR data set, use of XLPE markedly reduces the risk of revision. Level of evidence Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

STUDY DESIGN A prospective observational international study. OBJECTIVE The aim of this study was to evaluate outcomes of decompressive surgery in patients with very severe degenerative cervical myelopathy (DCM). SUMMARY OF BACKGROUND DATA Although decompressive surgery has been evidenced as a safe and effective approach for patients with myelopathic deficiencies, studies have suggested residual disability following treatment in patients with more severe disease presentation. METHODS Postoperative outcomes of 60 patients with very severe DCM (modified Japanese Orthopaedic Association [mJOA] score ≤8) were compared to outcomes of 188 patients with severe DCM (mJOA 9-11). Postimputation follow-up rate was 93.1%. Unadjusted and adjusted analyses were performed using two-way repeated measures of covariance. RESULTS The two cohorts were similar in demographics, length of duration of myelopathy symptoms, source of stenosis, and surgical approaches used to decompress the spine. The very severe and severe cohorts differed in preoperative Nurick grades (4.97 vs. 3.91, respectively, P

BACKGROUND CONTEXT Surgical decompression has been shown to improve long-term function, disability and quality of life (QOL) in degenerative cervical myelopathy (DCM); however, the role of surgery, and the effect on functional and QOL outcomes, in elderly patients with DCM is controversial. PURPOSE To investigate the effect of older age (over 70) on the functional and QOL impairment and outcomes after DCM surgery compared to younger adults. STUDY DESIGN/SETTING Prospective, multicentre observational studies on the outcomes of surgery for DCM; the AO Spine CSM-North America and the CSM-International studies. PATIENT SAMPLE A harmonized, combined dataset of 757 patients enrolled from both studies. OUTCOME MEASURES Functional assessment was performed with the modified Japanese Orthopedic Association score (mJOA). QOL outcomes were measured by the SF-36 physical and mental component scores. METHODS Of 757 patients enrolled in both studies, 107 patients were identified as elderly (70 years or older) at the time of surgery. Outcomes and functional status were assessed at 6-, 12- and 24-month intervals. In addition to unadjusted univariate analyses, multiple linear regression was used to evaluate the effect of age ≥70 on change in outcome scores adjusting for diabetes, cardiac comorbidities, cigarette smoking, psychiatric disorders, number of operated levels, surgical approach and baseline mJOA. RESULTS The baseline mJOA in the elderly group was significantly lower than the younger group (11.0 [95% CI 10.4-11.5] vs 12.9 [12.7-13.1]; p= CONCLUSIONS In this combined dataset from 2 large prospectively collected multicentre studies on DCM surgery, the group aged 70 or greater demonstrated significantly worse functional and QOL recovery when compared to the younger cohort after adjusting for the effect of comorbidities, number of operated levels, surgical approach and baseline mJOA. Elderly patients undergoing surgery for DCM should therefore be counseled appropriately regarding expectations of surgery. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Background: Riluzole is a sodium channel-blocking agent used in treating amyotrophic lateral sclerosis. It has been approved by the U.S. Food and Drug Administration, Canadian and Australian authorities, and in many other countries. A phase I trial of riluzole for acute spinal cord injury (SCI) provided safety and pharmacokinetic data and suggested neuroprotective benefits. A phase IIB/III double-blinded randomized controlled trial (RCT) started in January 2014 (https://clinicaltrials.gov, NCT01597518). This article describes the pathophysiological rationale, preclinical experience and design of the phase IIB/III RCT of Riluzole in Acute Spinal Cord Injury Study (RISCIS). Objectives: The primary objective of the trial is to evaluate the superiority of riluzole, at a dose of 100 mg BID in the first 24 h followed by 50 mg BID for the following 13 days post injury, compared with placebo in improving neurological motor outcomes in patients with C4–C8 level, International Standards for Neurological Classification of Spinal Cord Injury Examination (ISNCSCI) grade A, B or C acute (within 12 h post injury) SCI. Setting: Acute trauma centers worldwide Methods: A double-blind, multi-center, placebo-controlled RCT will enroll 351 participants randomized 1:1 to riluzole and placebo. The primary end point is the change between 180 days and baseline in ISNCSCI Motor Score. This study has 90% power to detect a change of nine points in ISNCSCI Motor Score at one-sided α=0.025. Results: Currently enrolling in 11 centers. Conclusion: This study will provide class I evidence regarding the safety and neuroprotective efficacy of riluzole in patients with acute cervical SCI.

Background Modern knee prostheses are designed to more closely replicate normal knee kinematics. The JOURNEY II Bi-Cruciate Stabilized Total Knee System (Smith & Nephew Inc., Memphis, TN) is a second-generation motion-guided knee system that demonstrates axial rotation patterns during flexion, which resemble those of the normal knee. The aim of this study was to assess the short-term safety and effectiveness of this system in standard clinical practice. Methods A total of 186 subjects (209 primary total knee arthroplasties [TKAs]) were enrolled at 12 U.S. sites. Subjects were operated on between December 2011 and October 2013 and followed for 24 months. Radiographic, clinical, and patient-reported outcome data were collected at 6-, 12-, and 24-month postoperatively. Results At 24-month follow-up, the average objective Knee Society Score was 96.20 (standard deviation [SD] = 6.63), the average satisfaction score was 35.22 (SD = 6.63), the average expectation score was 10.91 (SD = 3.16), and the average functional activities score was 81.49 (SD = 14.65). On a 0-10 scale, pain level for walking was 0.79 (SD = 1.51) and 1.50 (SD = 1.97) for climbing stairs or inclines. The cumulative incidence of reoperation at 2-year follow-up was 1.48% (95% confidence interval [CI] 0.48%-4.52%). Ten TKAs in 7 patients were treated with closed manipulations for stiffness. Iliotibial band syndrome was reported in 2 TKAs. Two deep infections occurred, 1 requiring reoperation. No dislocations occurred in the study cohort. Conclusions In short-term follow-up, the JOURNEY II Bi-Cruciate Stabilized Guided Motion Total Knee System appears to be a safe and effective device for TKA.

This study was designed to identify preoperative predictors of survival in surgically treated patients with metastatic epidural spinal cord compression (MESCC), to examine how these predictors are related to 8 prognostic models, and to perform the first full external validation of these models in accordance with the Transparent Reporting of a Multivariable Prediction Model for Individual Prognosis or Diagnosis (TRIPOD) statement.One hundred forty-two surgically treated patients with MESCC were enrolled in a prospective, multicenter North American cohort study and were followed for 12 months or until death. Cox regression was used. Noncollinear predictors with 10% missing data, with ≥ 10 events per stratum, and with P .05 in a univariate analysis were tested through a backward stepwise selection. For the original and revised Tokuhashi prognostic scoring systems (PSSs), Tomita PSS, modified Bauer PSS, van der Linden PSS, Bartels model, Oswestry Spinal Risk Index, and Bollen PSS, this study examined calibration graphically, discrimination with Harrell c-statistics, and survival stratified by risk groups with the Kaplan-Meier method and log-rank test.The following were significant in the univariate analysis: type of primary tumor, sex, organ metastasis, body mass index, preoperative radiotherapy to MESCC, physical component (PC) of the 36-Item Short Form Health Survey, version 2 (SF-36v2), and EuroQol 5-Dimension (EQ-5D) Questionnaire. Breast, prostate and thyroid primary tumor (HR: 2.9; P =.0005), presence of organ metastasis (hazard ratio (HR): 2.0; P = .005) and SF-36v2 PC (HR: 0.95; P.0001) were associated with survival in multivariable analysis. Predicted prognoses poorly matched observed values on calibration plots; Bartels model calibration slope was 0.45. Bollen PSS (0.61; 95% CI: 0.58-0.64) and Bartels model (0.68; 95% CI: 0.65-0.71) had the lowest and highest c-statistics, respectively.The primary tumor type (breast, prostate, or thyroid), an absence of organ metastasis, and a lower degree of physical disability are preoperative predictors of longer survival for surgical MESCC patients. These results are in keeping with current models. This full external validation of 8 prognostic PSSs or model of survival in surgical MESCC patients has revealed that calibration is poor, especially for long-term survivors, whereas discrimination is possibly helpful.

Background Although dysphagia is a common complication after anterior cervical decompression and fusion, important risk factors have not been rigorously evaluated. Furthermore, the impact of dysphagia on neurological and quality-of-life outcomes is not fully understood. The aim of this study was to determine the prevalence of and risk factors for dysphagia, and the impact of this complication on short and long-term clinical outcomes, in patients treated with anterior cervical decompression and fusion. Methods Four hundred and seventy patients undergoing a 1-stage anterior or 2-stage anteroposterior cervical decompression and fusion were enrolled in the prospective AOSpine CSM (Cervical Spondylotic Myelopathy) North America or International study at 26 global sites. Logistic regression analyses were conducted to determine important clinical and surgical predictors of perioperative dysphagia. Preoperatively and at each follow-up visit, patients were evaluated using the modified Japanese Orthopaedic Association scale (mJOA), Nurick score, Neck Disability Index (NDI), and Short Form-36 Health Survey (SF-36). A 2-way repeated-measures analysis of covariance was used to evaluate differences in outcomes at 6 and 24 months between patients with and those without dysphagia, while controlling for relevant baseline characteristics and surgical factors. Results The overall prevalence of dysphagia was 6.2%. Bivariate analysis showed the major risk factors for perioperative dysphagia to be a higher comorbidity score, older age, a cardiovascular or endocrine disorder, a lower SF-36 Physical Component Summary score, 2-stage surgery, and a greater number of decompressed levels. Multivariable analysis showed patients to be at an increased risk of perioperative dysphagia if they had an endocrine disorder, a greater number of decompressed segments, or 2-stage surgery. Both short and long-term improvements in functional, disability, and quality-of-life scores were comparable between patients with and those without dysphagia. Conclusions The most important predictors of dysphagia are an endocrine disorder, a greater number of decompressed levels, and 2-stage surgery. At the time of both short and long-term follow-up, patients with perioperative dysphagia exhibited improvements in functional, disability, and quality-of life scores that were similar to those of patients without dysphagia. Level of evidence Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Item does not contain fulltext PURPOSE: We aimed to determine cut-offs between mild, moderate and severe myelopathy on the modified Japanese Orthopedic Association (mJOA) score. METHODS: Between December 2005 and January 2011, 757 patients with clinically diagnosed DCM were enrolled in the prospective AOSpine North America (n = 278) or International (n = 479) study at 26 sites. Functional status and quality of life were evaluated at baseline using a variety of outcome measures. Using the Nurick score as an anchor, receiver operating curve (ROC) analysis was conducted to determine cut-offs between mild, moderate and severe disease. The validity of the identified cut-offs was evaluated by examining whether patients in different severity groups differed in terms of impairment, disability, quality of life and number of signs and symptoms. RESULTS: A mJOA of 14 was determined to be the cut-off between mild and moderate myelopathy and a mJOA of 11 was the cut-off score between moderate and severe disease. Patients in the severe myelopathy group (n = 254) had significantly reduced quality of life and functional status and a greater number of signs and symptoms compared to patients classified as mild (n = 190) or moderate (n = 296). CONCLUSIONS: Mild myelopathy can be defined as mJOA from 15 to 17, moderate as mJOA from 12 to 14 and severe as mJOA from 0 to 11. These categories should be adopted worldwide to standardize clinical assessment of DCM.

This study introduced a prototype of an axial-stress bioreactor system that supports long-term growth and development of engineered tissues. The main features of this bioreactor are an integrated substance exchanger and feedback control of pH and PO₂. A 21-day study was conducted to validate the system's ability to maintain a stable environment, while remaining sterile. Our results showed that the pH, PO₂, and nutrient (glucose) remained balanced at appropriate levels, while metabolic waste (lactic acid) was removed. No bacteria or fungi were detected in the system or tissue; thus, demonstrating that it was sterile. These data indicate the bioreactor's strong potential for long-term tissue culture. To explore this idea, the effect of dynamic culture, including cyclic compression and automatic substance exchange, on mouse bone-marrow mesenchymal stem cells (BMSCs) seeded in decalcified bone matrix was studied using the bioreactor prototype. Histological sections of the engineered tissues showed higher cell densities in scaffolds in dynamic culture compared to those in static culture, while cell cycle analysis showed that dynamic culture promoted BMSC proliferation (proliferation index, PI=34.02±1.77) more effectively than static culture (PI=26.66±1.81). The results from a methyl thiazolyl tetrazolium assay were consistent with the loading experimental data. Furthermore, elevated alkaline phosphatase activity and calcium content were observed in dynamic condition compared to static culture. In conclusion, this bioreactor system supplies a method of modulating the pH and PO₂ in defined ranges with only small fluctuations; it can be used as a physiological or pathological analog. Automatic control of the environment is a practical solution for long-term, steady-state culture for future commercialization.

Background context Cervical spondylotic myelopathy (CSM) is a chronic spinal cord disease and can lead to progressive or stepwise neurologic decline. Several factors may influence this process, including extent of spinal cord compression, duration of symptoms, and medical comorbidities. Diabetes is a systemic disease that can impact multiple organ systems, including the central and peripheral nervous systems. There has been little information regarding the effect of diabetes on patients with coexistent CSM. Purpose To provide empirical data regarding the effect of diabetes on treatment outcomes in patients who underwent surgical decompression for coexistent CSM. Study design/setting Large prospective multicenter cohort study of patients with and without diabetes who underwent decompressive surgery for CSM. Patient sample Two hundred thirty-six patients without and 42 patients with diabetes were enrolled. Of these, 37 were mild cases and five were moderate cases. Four required insulin. There were no severe cases associated with end-organ damage. Outcome measures Self-report measures include Neck Disability Index and version 2 of 36-Item Short Form Health Survey (SF-36v2), and functional measures include modified Japanese Orthopedic Association (mJOA) score and Nurick grade. Methods We compared presurgery symptoms and treatment outcomes between patients with and without diabetes using univariate and multivariate models, adjusting for demographics and comorbidities. Results Diabetic patients were older, less likely to smoke, and more likely to be on social security disability insurance. Patients with diabetes presented with a worse Nurick grade, but there were no differences in mJOA and SF-36v2 at presentation. Overall, there was a significant improvement in all outcome parameters at 12 and 24 months. There was no difference in the level of improvement between the patients with and without diabetes, except in the SF-36v2 Physical Functioning, in which diabetic patients experienced significantly less improvement. There were no differences in surgical complication rates between diabetic patients and nondiabetic patients. Conclusions Except for a worse Nurick grade, diabetes does not seem to affect severity of symptoms at presentation for surgery. More importantly, with the exception of the SF-36v2 Physical Functioning scores, outcomes of surgical treatment are similar in patients with diabetes and without diabetes. Surgical decompression is effective and should be offered to patients with diabetes who have symptomatic CSM and are appropriate surgical candidates.

BACKGROUND CONTEXT There is convincing evidence from the preclinical realm that the pharmacologic agent riluzole attenuates certain aspects of the secondary injury cascade leading to diminished neurological tissue destruction in animal SCI models. The safety and pharmacokinetic profile of riluzole have been studied in a multicenter pilot study in 36 patients. Efficacy of riluzole in acute human SCI has not been established. PURPOSE This study aims to investigate efficacy of riluzole in acute SCI. STUDY DESIGN/SETTING This is an ongoing multicenter, international double-blinded phase III RCT. PATIENT SAMPLE A total of 351 patients with acute C4–C8 SCI and ASIA impairment grade A, B or C OUTCOME MEASURES Primary outcome is the change in ASIA motor score (AMS) between baseline and 180 days. Other outcomes include ASIA upper and lower extremity MS; ASIA sensory score; ASIA grade; SCIM); SF-36v2; EQ-5D and GRASSP. METHODS A total of 351 patients with acute C4–C8 SCI and ASIA impairment grade A, B or C randomized 1:1 to riluzole and placebo. Primary outcome is the change in ASIA motor score (AMS) between baseline and 180 days. Other outcomes include ASIA upper and lower extremity MS; ASIA sensory score; ASIA grade; SCIM); SF-36v2; EQ-5D and GRASSP. Two-stage sequential adaptive trial statistical design has 90% power to detect 9 points difference in the ASIA motor score at one-sidedalpha=.025. RESULTS A matched cohort analysis performed in the Phase I study showed that riluzole treated cervical SCI patients experienced an additional 15.5 points in AMS recovery at 90 days post injury. Although the phase I study was underpowered to investigate efficacy the current phase III study is poised to definitive address this question. To date, 112 subjects have been enrolled. Average age of the enrolled subjects is 48.0 (SD 16.4); 84% males. ASIA at arrival and preInjury status, ASIA grade A (48%), B (27%), C (25%). GRASSP 64.6 (SD 61.4), SF35v2 PCS 53.0(SD 9.0) SF36v2 MCS 54.3 (SD 11.5). CONCLUSIONS This is a Phase III study of riluzole in acute SCI. FDA DEVICE/DRUG STATUS Riluzole (Not approved for this indication).

Background: The effect on functional and quality of life (QOL) outcomes of surgery in elderly degenerative cervical myelopathy (DCM) patients has not been definitively established. Objective: To evaluate the effect of older age on the functional and QOL outcomes after surgery in an international, multi-center cohort of patients with DCM. Methods: 107 patients aged over 70 years old (mean 75.6 &plusmn, 4.4 years) were enrolled in the AOSpine CSM-North America and International studies. A propensity-matched cohort of 107 patients was generated from the remaining 650 adults aged &lt, 70 years old (mean 56.3 &plusmn, 9.6 years), matched to gender, complexity of surgery, co-morbidities, and baseline functional impairment (modified Japanese Orthopedic Association scale (mJOA). Functional, disability, and QOL outcomes were compared at baseline and at two years post-operatively, along with peri-operative adverse events. Results: Both cohorts were equivalently matched. At two years, both cohorts showed significant functional improvement from the baseline but the magnitude was greater in the younger cohort (mJOA 3.8 (3.2&ndash, 4.4) vs. 2.6 (2.0&ndash, 3.3), p = 0.007). This difference between groups was also observed in the SF-36 physical component summary (PCS) and mental component summary (MCS) outcomes (p = &lt, 0.001, p = 0.007), but not present in the neck disability index (NDI) scores (p = 0.094). Adverse events were non-significantly higher in the elderly cohort (22.4% vs. 15%, p = 0.161). Conclusions: Elderly patients showed an improvement in functional and QOL outcomes after surgery for DCM, but the magnitude of improvement was less when compared to the matched younger adult cohort. An age over 70 was not associated with an increased risk of adverse events.

STUDY DESIGN A prospective observational multicenter study. OBJECTIVE To help solve the debate regarding whether the anterior or posterior surgical approach is optimal for patients with cervical spondylotic myelopathy (CSM). SUMMARY OF BACKGROUND DATA The optimal surgical approach to treat CSM remains debated with varying opinions favoring anterior versus posterior surgical approaches. We present an analysis of a prospective observational multicenter study examining outcomes of surgical treatment for CSM. METHODS A total of 278 subjects from 12 sites in North America received anterior/posterior or combined surgery at the discretion of the surgeon. This study focused on subjects who had either anterior or posterior surgery (n = 264, follow-up rate, 87%). Outcome measures included the modified Japanese Orthopedic Assessment scale, the Nurick scale, the Neck Disability Index, and the Short-Form 36 (SF-36) Health Survey version 2 Physical and Mental Component Scores. RESULTS One hundred and sixty-nine patients were treated anteriorly and 95 underwent posterior surgery. Anterior surgical cases were younger and had less severe myelopathy as assessed by mJOA and Nurick scores. There were no baseline differences in Neck Disability Index or SF-36 between the anterior and posterior cases. Improvement in the mJOA was significantly lower in the anterior group than posterior group (2.47 vs. 3.62, respectively, P < 0.01), although the groups started at different levels of baseline impairment. The extent of improvement in the Nurick Scale, Neck Disability Index, SF-36 version 2 Physical Component Score, and SF-36 version 2 Mental Component Score did not differ between the groups. CONCLUSION Patients with CSM show significant improvements in several health-related outcome measures with either anterior or posterior surgery. Importantly, patients treated with anterior techniques were younger, with less severe impairment and more focal pathology. We demonstrate for the first time that, when patient and disease factors are controlled for, anterior and posterior surgical techniques have equivalent efficacy in the treatment of CSM. LEVEL OF EVIDENCE 3.

Study design Descriptive article and narrative review. Objective To explain the rationale and design of the cervical spondylotic myelopathy (CSM)-Protect clinical trial that aims to elucidate the efficacy and safety of riluzole in the context of CSM. Summary of background data CSM is the most common cause of spinal cord-related dysfunction internationally. Although surgery is effective in preventing the progression of impairment, and in some cases improving functional outcomes, many patients continue to exhibit significant disability in the postoperative setting. Evidence from preclinical studies suggests that glutamate-related excitotoxicity may contribute to the pathology of CSM and that administration of the sodium and glutamate-blocking medication riluzole, when combined with spinal cord decompression, may mitigate this effect and improve neurobehavioral outcomes. Although riluzole is FDA approved and has been shown to be safe and effective in the context of amyotrophic lateral sclerosis, its efficacy and safety in the context of CSM remain unknown. Methods Descriptive article with narrative review of the literature. Results In addition to providing pertinent preclinical background on the topic, this descriptive article and narrative review discusses the design and current status of an ongoing phase III randomized controlled trial evaluating the efficacy and safety of riluzole, combined with surgical decompression, in the treatment of CSM. Conclusion On the basis of current projections, we estimate that the interim analysis for this study will take place in the spring of 2014, at which time an adaptive sample size adjustment may take place.

Study design Subgroup analysis of a prospective multicenter study. Objective Outcome analysis of nonoperatively treated elderly patients with type II odontoid fractures, including assessment of consequence of a fracture nonunion. Summary of background data Odontoid fractures are among the most common fractures in the elderly, and controversy exists regarding treatment. Methods Subgroup analysis of a prospective multicenter study of elderly patients (≥65 yr) with type II odontoid fracture. Neck Disability Index and Short-Form 36 (SF-36) version 2 were collected at baseline and 6 and 12 months. Fifty-eight (36.5%) of the 159 patients were treated nonoperatively. Results Of the 58 patients initially treated nonoperatively, 8 died within 90 days and were excluded. Of the remaining 50 patients, 11 (22.0%) developed nonunion, with 7 (63.6%) requiring surgery. Four of the 39 (10.3%) patients classified as having "successful union" required surgery due to late fracture displacement. Thus, 15 (30.0%) patients developed primary or secondary nonunion and 11 (22.0%) required surgery. The overall 12-month mortality was 14.0% (nonunion = 2, union = 5; P= 0.6407). For union and nonunion groups, Neck Disability Index and SF-36 version 2 declined significantly at 12 months compared with preinjury values (P 0.05); however, it is important to emphasize that the 12-month outcomes for the nonunion patients reflect the status of the patient after delayed surgical treatment in the majority of these cases. Conclusion Nonoperative treatment for type II odontoid fracture in the elderly has high rates of nonunion and mortality. Patients with nonunion did not report worse outcomes compared with those who achieved union at 12 months; however, the majority of patients with nonunion required delayed surgical treatment. These findings may prove useful for patients who are not surgical candidates or elect for nonoperative treatment. Level of evidence 2.

Background: Cervical spondylotic myelopathy is a progressive spine disease and the most common cause of spinal cord dysfunction worldwide. The objective of this study was to develop a prediction model, based on data from a prospective multi-center study, relating a combination of clinical and imaging variables to surgical outcome in patients with cervical spondylotic myelopathy. Methods: Two hundred and seventy-eight patients diagnosed with cervical spondylotic myelopathy treated surgically were enrolled at twelve different sites in the multi-center AOSpine North America study. Univariate analyses were performed to evaluate the relationship between outcome, assessed with the modified Japanese Orthopaedic Association (mJOA) score, and various clinical and imaging predictors. A set of important candidate variables for the final model was selected on the basis of author consensus, literature support, and statistical findings. Logistic regression was used to formulate the final model. Results: Univariate analyses demonstrated that the odds of a successful outcome decreased with a longer duration of symptoms (odds ratio [OR] = 0.80, 95% confidence interval [CI] = 0.65 to 0.98, p = 0.030); a lower baseline mJOA score (OR = 0.74, 95% CI = 0.65 to 0.84, p < 0.0001); the presence of psychological comorbidities (OR = 0.51, 95% CI = 0.29 to 0.92, p = 0.024); the presence of broad-based, unstable gait (OR = 2.72, 95% CI = 1.47 to 5.06, p = 0.0018) or other gait impairment (OR = 3.56, 95% CI = 1.75 to 7.22, p = 0.0005); and older age (OR = 0.96, 95% CI = 0.93 to 0.98, p = 0.0004). The dependent variable, the mJOA score at one year, was dichotomized for logistic regression: a “successful” outcome was defined as a final score of ≥16 and a “failed” outcome was a score of