Aims. The aim of this study was to identify the risk factors for adverse events following the surgical correction of cervical spinal deformities in adults. Methods. We identified adult patients who underwent corrective cervical spinal surgery between 1 January 2007 and 31 December 2015 from the MarketScan database. The baseline comorbidities and characteristics of the operation were recorded. Adverse events were defined as the development of a complication, an unanticipated deleterious postoperative event, or further surgery. Patients aged < 18 years and those with a previous history of tumour or trauma were excluded from the study. Results. A total of 13,549 adults in the database underwent primary corrective surgery for a cervical spinal deformity during the study period. A total of 3,785 (27.9%) had a complication within 90 days of the procedure, and 3,893 (28.7%) required further surgery within two years. In multivariate analysis, male sex (odds ratio (OR) 0.90 (95% confidence interval (CI) 0.8 to 0.9); p = 0.019) and a posterior approach (compared with a combined surgical approach, OR 0.66 (95% CI 0.5 to 0.8); p < 0.001) significantly decreased the risk of complications. Osteoporosis (OR 1.41 (95% CI 1.3 to 1.6); p < 0.001), dyspnoea (OR 1.48 (95% CI 1.3 to 1.6); p < 0.001), cerebrovascular accident (OR 1.81 (95% CI 1.6 to 2.0); p < 0.001), a posterior approach (compared with an anterior approach, OR 1.23 (95% CI 1.1 to 1.4); p < 0.001), and the use of bone morphogenic protein (BMP) (OR 1.22 (95% CI 1.1 to 1.4); p = 0.003) significantly increased the risks of 90-day complications. In multivariate regression analysis, preoperative dyspnoea (OR 1.50 (95% CI 1.3 to 1.7); p < 0.001), a posterior approach (compared with an anterior approach, OR 2.80 (95% CI 2.4 to 3.2; p < 0.001), and postoperative dysphagia (OR 2.50 (95% CI 1.8 to 3.4); p < 0.001) were associated with a significantly increased risk of further surgery two years postoperatively. A posterior approach (compared with a combined approach, OR 0.32 (95% CI 0.3 to 0.4); p < 0.001), the use of BMP (OR 0.48 (95% CI 0.4 to 0.5); p < 0.001) were associated with a significantly decreased risk of further surgery at this time. Conclusion. The surgical approach and intraoperative use of BMP strongly influence the risk of further surgery, whereas the comorbidity burden and the characteristics of the operation influence the rates of early complications in adult patients undergoing corrective cervical spinal surgery. These data may aid surgeons in patient selection and surgical planning. Cite this article: Bone Joint J 2021;103-B(4):734–738

Aims. The purpose of this retrospective study was to investigate the clinical relevance of increased facet joint distraction as a result of anterior cervical decompression and fusion (ACDF) for trauma. Patients and Methods. A total of 155 patients (130 men, 25 women. Mean age 42.7 years; 16 to 87) who had undergone ACDF between 1 January 2001 and 1 January 2016 were included in the study. Outcome measures included the Neck Disability Index (NDI) and visual analogue scale (VAS) for pain. Lateral cervical spine radiographs taken in the immediate postoperative period were reviewed to compare the interfacet distance of the operated segment with those of the facet joints above and below. Results. There was a statistically significant relationship between greater facet distraction and increased NDI and VAS pain scores. This was further confirmed by Spearman correlation, which showed evidence of a moderate correlation between both NDI score and facet joint distraction (Spearman correlation coefficient 0.34; p < 0.001) and VAS score and facet distraction (Spearman correlation coefficient 0.52; p < 0.001). Furthermore, there was a discernible transition point between outcome scores. Significantly worse outcomes, in terms of both NDI scores (17.8 vs 8.2; p < 0.001) and VAS scores (4.5 vs 1.3; p < 0.001), were seen with facet distraction of 3 mm or more. Patients who went on to have a posterior fusion also had increased NDI and VAS scores, independent of facet distraction. Conclusion. After undergoing ACDF for the treatment of cervical spine injury, patients with facet joint distraction of 3 mm or more have worse NDI and VAS pain scores. Cite this article: Bone Joint J 2018;100-B:1201–7

This study evaluates factors related to myelopathic symptoms in patients with ossification of the posterior longitudinal ligament (OPLL). A total of 87 patients with OPLL were included. Of these, 53 (Group I) had no symptoms or presented with neck pain and radiculopathy and 34 (Group II) had myelopathic symptoms. Gender, age, and history of trauma were evaluated in the two groups. The range of movement of the cervical spine was measured using plain radiographs. The number of involved segments, type of OPLL, and maximal compression ratio were analysed using CT and signal change in the spinal cord was evaluated using MRI.

The patients’ age was found to be significant (p = 0.001). No difference was found between gender and the range of movement in the two groups. The maximum compression of the spinal canal showed a difference (p = 0.03). The signal change of the spinal cord was different between the two groups. In patients with OPLL of the cervical spine, myelopathic symptoms are not related to the range of movement or the number of involved segments.

Aims. The optimal procedure for the treatment of ossification of the posterior longitudinal ligament (OPLL) remains controversial. The aim of this study was to compare the outcome of anterior cervical ossified posterior longitudinal ligament en bloc resection (ACOE) with posterior laminectomy and fusion with bone graft and internal fixation (PTLF) for the surgical management of patients with this condition. Methods. Between July 2017 and July 2019, 40 patients with cervical OPLL were equally randomized to undergo surgery with an ACOE or a PTLF. The clinical and radiological results were compared between the two groups. Results. The Japanese Orthopaedic Association (JOA) score and recovery rate in the ACOE group were significantly higher than those in the PTLF group during two years postoperatively, provided that the canal occupying ratio (COR) was > 50%, or the K-line was negative. There was no significant difference in JOA scores and rate of recovery between the two groups in those in whom the COR was < 50%, or the K-line was positive. There was no significant difference in the Cobb angle between C2 and C7, sagittal vertical axis, cervical range of motion (ROM), and complications between the two groups. Conclusion. Compared with PTLF, ACOE is a preferred surgical approach for the surgical management of patients with cervical OPLL in that it offers a better therapeutic outcome when the COR is > 50%, or the K-line is negative, and it also preserves better cervical curvature and sagittal balance. The prognosis of ACOE is similar to that of PTLE when the COR is < 50%, or the K-line is positive. Cite this article: Bone Joint J 2023;105-B(4):412–421

In multilevel posterior cervical instrumented fusions, extending the fusion across the cervico-thoracic junction at T1 or T2 (CTJ) has been associated with decreased rate of re-operation and pseudarthrosis but with longer surgical time and increased blood loss. The impact on patient reported outcomes (PROs) remains unclear. The primary objective was to determine whether extending the fusion through the CTJ influenced PROs at 3 and 12 months after surgery. Secondary objectives were to compare the number of patients reaching the minimally clinically important difference (MCID) for the PROs and mJOA, operative time duration, intra-operative blood loss (IOBL), length of stay (LOS), discharge disposition, adverse events (AEs), re-operation within 12 months of the surgery, and patient satisfaction. This is a retrospective analysis of prospectively collected data from a multicenter observational cohort study of patients with degenerative cervical myelopathy. Patients who underwent a posterior instrumented fusion of 4 levels of greater (between C2-T2) between January 2015 and October 2020 with 12 months follow-up were included. PROS (NDI, EQ5D, SF-12 PCS and MCS, NRS arm and neck pain) and mJOA were compared using ANCOVA, adjusted for baseline differences. Patient demographics, comorbidities and surgical details were abstracted. Percentafe of patient reaching MCID for these outcomes was compared using chi-square test. Operative duration, IOBL, AEs, re-operation, discharge disposittion, LOS and satisfaction were compared using chi-square test for categorical variables and independent samples t-tests for continuous variables. A total of 206 patients were included in this study (105 patients not crossing the CTJ and 101 crossing the CTJ). Patients who underwent a construct extending through the CTJ were more likely to be female and had worse baseline EQ5D and NDI scores (p> 0.05). When adjusted for baseline difference, there was no statistically significant difference between the two groups for the PROs and mJOA at 3 and 12 months. Surgical duration was longer (p 0.05). Satisfaction with the surgery was high in both groups but significantly different at 12 months (80% versus 72%, p= 0.042 for the group not crossing the CTJ and the group crossing the CTJ, respectively). The percentage of patients reaching MCID for the NDI score was 55% in the non-crossing group versus 69% in the group extending through the CTJ (p= 0.06). Up to 12 months after the surgery, there was no statistically significant differences in PROs between posterior construct extended to or not extended to the upper thoracic spine. The adverse event profile did not differ significantly, but longer surgical time and blood loss were associated with construct extending across the CTJ

We present data relating to the Bryan disc arthroplasty for the treatment of cervical spondylosis in 46 patients. Patients with either radiculopathy or myelopathy had a cervical discectomy followed by implantation of a cervical disc prosthesis. Patients were reviewed at six weeks, six months and one year and assessment included three outcome measures, a visual analogue scale (VAS), the short form 36 (SF-36) and the neck disability index (NDI). The results were categorised according to a modification of Odom’s criteria. Radiological evaluation, by an independent radiologist, sought evidence of movement, stability and subsidence of the prosthesis. A highly significant difference was found for all three outcome measurements, comparing the pre-operative with the post-operative values: VAS (Z = 6.42, p < 0.0001), SF-36 (mental component) (Z = −5.02, p < 0.0001), SF-36 (physical component) (Z = −5.00, p < 0.0001) and NDI (Z = 7.03, p < 0.0001). The Bryan cervical disc prosthesis seems reliable and safe in the treatment of patients with cervical spondylosis

We present a novel method of performing an ‘open-door’ cervical laminoplasty. The complete laminotomy is sited on alternate sides at successive levels, thereby allowing the posterior arch to be elevated to alternate sides. Foraminotomies can be carried out on either side to relieve root compression. The midline structures are preserved. We undertook this procedure in 23 elderly patients with a spondylotic myelopathy. Each was assessed clinically and radiologically before and after their operation. Follow-up was for a minimum of three years (mean 4.5 years; 3 to 7). Using the modified Japanese Orthopaedic Association scoring system, the mean pre-operative score was 8.1 (6 to 10), which improved post-operatively to a mean of 12.7 (11 to 14). The mean percentage improvement was 61% (50% to 85.7%) after three years. The canal/vertebral body ratio improved from a mean of 0.65 (0.33 to 0.73) pre-operatively to 0.94 (0.5 to 1.07) postoperatively. Alternating cervical laminoplasty can be performed safely in elderly patients with minimal morbidity and good results

A retrospective follow-up study was done, assessing regional practices in acute cervical reduction in hospitals in the Western Cape. The constitutional court ruled on the urgency in managing cervical dislocations, and our task is to ensure that medical treatment is optimized to comply with best medical practice and the apex court. A questionnaire was distributed and completed by emergency departments at each hospital, the results retrieved, analysed, and compared to a similar survey done in 2016. Protocols for managing cervical spine dislocations had improved from 80% having no protocols to only over half of facilities (52,6%) not having protocols in place. Inadequate equipment availability remained a problem with only 50% of facilities having adequate equipment available in 2016 to 43,6% in 2023. 10,3% of participants did not know if there was equipment available. In terms of knowledge, there remained poor formal training with a drop from 93% participants identifying that the main indication to attempt emergency cervical reduction was acute cervical dislocation with worsening neurology, to only 46,2%. However, there was an increase in the number of participants who thought reduction was safe. The same percentage of participants from 2016 to 2023 would attempt emergency cervical reduction if given adequate training. Previously we found that most Western Cape hospitals had inadequate protocols, training, and equipment for cervical reductions. In 2023, more hospitals in the Province have protocols in place for cervical reductions and the same percentage of doctors would attempt emergency cervical reduction with adequate training. However, equipment and training for management of acute cervical dislocations has not improved. We conclude that most Western Cape Hospitals are unprepared to adequately manage acute cervical dislocations

Aims. Surgical approaches to cervical ossification of the posterior longitudinal ligament (OPLL) remain controversial. The purpose of the present study was to analyze and compare the long-term neurological recovery following anterior decompression with fusion (ADF) and posterior laminectomy and fusion with bone graft and internal fixation (PLF) based on > ten-year follow-up outcomes in a single centre. Methods. Included in this retrospective cohort study were 48 patients (12 females; mean age 55.79 years (SD 8.94)) who were diagnosed with cervical OPLL, received treatment in our centre, and were followed up for 10.22 to 15.25 years. Of them, 24 patients (six females; mean age 52.88 years (SD 8.79)) received ADF, and the other 24 patients (five females; mean age 56.25 years (SD 9.44)) received PLF. Clinical data including age, sex, and the OPLL canal-occupying ratio were analyzed and compared. The primary outcome was Japanese Orthopaedic Association (JOA) score, and the secondary outcome was visual analogue scale neck pain. Results. Compared with the baseline, neurological function improved significantly after surgery in all patients of both groups (p < 0.001). The JOA recovery rate in the ADF group was significantly higher than that in the PLF group (p < 0.001). There was no significant difference in postoperative cervical pain between the two groups (p = 0.387). The operating time was longer and intraoperative blood loss was greater in the PLF group than the ADF group. More complications were observed in the ADF group than in the PLF group, although the difference was not statistically significant. Conclusion. Long-term neurological function improved significantly after surgery in both groups, with the improvement more pronounced in the ADF group. There was no significant difference in postoperative neck pain between the two groups. The operating time was shorter and intraoperative blood loss was lower in the ADF group; however, the incidence of perioperative complications was higher. Cite this article: Bone Jt Open 2024;5(9):768–775

Aims. Developmental cervical spinal stenosis (DcSS) is a well-known predisposing factor for degenerative cervical myelopathy (DCM) but there is a lack of consensus on its definition. This study aims to define DcSS based on MRI, and its multilevel characteristics, to assess the prevalence of DcSS in the general population, and to evaluate the presence of DcSS in the prediction of developing DCM. Methods. This cross-sectional study analyzed MRI spine morphological parameters at C3 to C7 (including anteroposterior (AP) diameter of spinal canal, spinal cord, and vertebral body) from DCM patients (n = 95) and individuals recruited from the general population (n = 2,019). Level-specific median AP spinal canal diameter from DCM patients was used to screen for stenotic levels in the population-based cohort. An individual with multilevel (≥ 3 vertebral levels) AP canal diameter smaller than the DCM median values was considered as having DcSS. The most optimal cut-off canal diameter per level for DcSS was determined by receiver operating characteristic analyses, and multivariable logistic regression was performed for the prediction of developing DCM that required surgery. Results. A total of 2,114 individuals aged 64.6 years (SD 11.9) who underwent surgery from March 2009 to December 2016 were studied. The most optimal cut-off canal diameters for DcSS are: C3 < 12.9 mm, C4 < 11.8 mm, C5 < 11.9 mm, C6 < 12.3 mm, and C7 < 13.3 mm. Overall, 13.0% (262 of 2,019) of the population-based cohort had multilevel DcSS. Multilevel DcSS (odds ratio (OR) 6.12 (95% CI 3.97 to 9.42); p < 0.001) and male sex (OR 4.06 (95% CI 2.55 to 6.45); p < 0.001) were predictors of developing DCM. Conclusion. This is the first MRI-based study for defining DcSS with multilevel canal narrowing. Level-specific cut-off canal diameters for DcSS can be used for early identification of individuals at risk of developing DCM. Individuals with DcSS at ≥ three levels and male sex are recommended for close monitoring or early intervention to avoid traumatic spinal cord injuries from stenosis. Cite this article: Bone Joint J 2024;106-B(11):1333–1341

Introduction. Degeneration of the cervical spine can lead to neurological symptoms that require surgical intervention. Often, an anterior cervical discectomy (ACD) with fusion is performed with interposition of a cage. However, a cage substantially increases health care costs. The polymer polymethylmethacrylate (PMMA) is an alternative to cages, associated with lower costs. The reported high-occurrence of non-fusion with PMMA is often seen as a drawback, but evidence for a correlation between radiological fusion and clinical outcome is absent. To investigate if the lower rate of fusion with PMMA has negative effects on long-term clinical outcome, we assessed the clinical results of ACD with PMMA as a intervertebral spacer with a 5–10 year follow-up. Methods. A retrospective cohort study among all patients who underwent a mono-level ACD with PMMA for degenerative cervical disease, between 2007–2012, was performed. Patients filled out an online questionnaire, developed to assess clinical long-term outcome, complications and re-operation rates. The primary outcome measure was the Neck Disability Index (NDI), secondary outcome measures were re-operation and complication rates. Results. Of 196 eligible patients, 90 patients were assessed (response rate 53%). The average NDI score at follow-up (mean 7.5 years) was 19.0 points ± 18.0 points. Complications occurred in 10% and re-operation in 8.8%. Conclusion. This study provides evidence of good long-term clinical results of ACD with PMMA, as the results were similar with long-term outcomes of ACD with a cage as spacer. Therefore, the results of this study may suggest that the use of PMMA is an lower-cost alternative. No conflicts of interests. No funding obtained

Background: Smaller versions of threaded lumbar cages were developed for cervical spine to obviate the need for allograft, iliac autograft use and to provide initial stability before fusion. Clinical trials of threaded cervical fusion cages have shown higher fusion rates and lower rates of graft-donor site complications. Study design/Aims: Prospective. Radiological and clinical outcomes of an age, sex and diagnosis matched patient population who underwent cervical fusion with (A) BAK/C cages filled with autograft reamings (Center-pulse Spine-tech Inc., Minneapolis, MN) (N=50) were compared with (B) Anterior cervical decompression and fusion (ACDF, N=50). Methods: Patients with symptomatic cervical discogenic radiculopathy were treated with either anterior cervical discectomy with uninstrumented bone-only fusion (ACDF) or BAK/C fusion cage(s). Independent radiographic assessment of fusion was made and patient-based outcome was assessed by a Short Form (SF)-36 Health Status Questionnaire. All patients had minimum follow up of at least 2 years. Results: Similar outcomes were noted for duration of surgery, hospital stay, improvements in neck pain and radicular pain in the affected limb, improvements in the SF-36 Physical Component subscale and Mental Component subscale, and the patients’ perception of overall surgical outcome. Symptom improvements were maintained at 2 years. Iliac crest harvesting was carried out as a standard procedure in all cases of ACDF whereas only 2 cases in BAK/C group required the same. Average operative time of 115 minutes and 145 minutes, blood loss of 110ml and 175ml and hospital stay of 1.5 and 3.5 days were noted for BAK/C and ACDF groups respectively. Successful fusion was achieved in 49 cases in BAK/C and 46 patients in ACDF group. None of the patients in the BAK/C group had reappearance of symptoms while 3 patients in ACDF group had developed symptomatic adjacent level disc disease. The complication rate for the ACDF group was 9% compared with an overall complication rate of 3% with BAK/C. Complications that necessitated a second operative procedure included. Graft dislodgement (N=3) and. Cage subsidence, both requiring re-operation in the form of ACDF with plate supplementation. Conclusions: These results demonstrate that outcomes after a cervical fusion procedure with a threaded cage are the same as those of a conventional uninstrumented bone-only anterior discectomy and fusion with a low risk of complications, less operative time and rare need for autogenous bone graft harvest

Aims: The Attempt to lay down indications for simultaneous applications Cornerstone Carbon Cage (CCS) and titanium plate in surgical treatment of cervical spondylosis with ligamental instability. Methods: Between November 2001 and august 2002 13 patient with ligamental instability underwent applications CCS and cervical plate during one ormultilevel cervical discectomy due to degenerative or posttraumatic cervical spondylosis. We never used external þxation. Results: There were no complications after operations. Preoperative symptoms withdrew in all patient. Good stabilisation was obtained in whole operated group. Conclusions: Simultaneous applications CCS and cervical plate is an effective method in surgical treatment cervical spondylosis with ligament instability. Appropriate stabilisation was obtained without additional external collar þxations and without necessity of autogenic bone graft

Study design. Prospective clinical and radiological analysis of children with complex cervical deformities for the safety of cervical pedicle screw insertion. Objectives. To analyse the possibility, safety and efficacy of cervical pedicle screw insertion in complex pediatric cervical deformities, where conventional stabilisation techniques would not have provided rigid fixation. Summary of Background Data. Although the usage of cervical pedicle screws (CPS) in adults has become established, the feasibility and safety of its application in children has not been described previously in the literature. Methods. Sixteen children of mean age 9.7 ± 2.6 years (range: 3 - 13) requiring spinal stabilization for cranio-vertebral junction anomalies (n=10), cervico-thoracic kyphosis/ kyphoscoliosis (n=5) and cervical tumor excision (n=1) formed the study group. Feasibility of CPS insertion was assessed by computerised tomography images. Standard 3.0 mm titanium pedicle screws were inserted using intraoperative Iso-C C arm based 3 D computer navigation and the containment was post operatively evaluated with CT scan. Results. Based on preoperative CT imaging, 55 pedicles were selected for screw fixation. Intra operatively CPS was successfully inserted at 51 levels and at four sclerosed pedicles (7.3%), screws could not be inserted. At 42 levels, the screws were inserted in the classical description of pedicle screw application and in nine deformed vertebra, the screws were inserted in a non-classical fashion, taking purchase in the three columns of the cervical vertebra. Forty five (88.3%) screws were fully contained, six (11.7 %) had a non-critical breach and none had a critical breach. No perioperative complications related to pedicle screw insertion were noted. Conclusion. Safe insertion of cervical pedicle screws is possible in children. Iso-C navigation provides real time virtual imaging and improves the safety and accuracy of successful pedicle fixation even in altered vertebral anatomy. Pedicle width morphometrics do not restrict screw insertion

Introduction: A prospective, randomized, controlled study has been conducted to compare the clinical outcomes of patients treated with an Artificial Cervical Disc to patients who receive fusion after cervical discectomy for the treatment of primary cervical disc disease. It is hypothesized that maintenance of motion after anterior cervical discectomy will prevent the high rate of adjacent level premature degeneration. The primary purpose of the study is to prove equivalence (non inferiority) of outcome of the disc prosthesis in the short term compared with fusion. Methods: In four centers, 60 patients with primary, single level cervical disc disease producing radiculopathy and/or myelopathy are randomized prospectively to receive anterior cervical discectomy with either fusion or artificial cervical disc placement. The patients are evaluated with pre and postoperative serial flexion-extension cervical x-rays at 6 weeks, 3, 6, 12, and 24 months. At the same intervals, the patients have pre and postoperative neck disability indexes, visual pain analogue scales, European myelopathy scores, SF-36 general health scores, and neurological status examinations assessing the patient’s reflex, motor and sensory function. Results: Data is presented for the first 47 patients. At 6 weeks the neck disability index reduced by 36.1 for the investigational group compared to 34.8 for the fusion group. The pain score had reduced by 8.2 for the investigational group and by 9.9 for the control group. This improvement appeared to be maintained until the 12 month followup. In general there appeared to be a slightly better outcome for the investigational group. Both pain score and disability scores improved statistically significantly compared to the pre op scores (p< 0.001 all comparisons). Analysis of non inferiority of outcome for the investigational group using ANCOVA with the preoperative score as the covariate and a non inferiority margin of 5 points showed statistical significance at 6 and 12 weeks for Neck disability index. Operative time appeared slightly less (2.3 hrs) for the investigational group compared to the fusion group(2.5hrs). Blood loss also appeared higher in the fusion group (165 mls compared to 91 mls). Hospital stay was equivalent (2.8 days and 2.9 days). Discussion: Anterior cervical discectomy and fusion has a good short term outcome though there is a high incidence of failure at adjacent levels over time. It is hypothesized that the maintenance of motion of a segment will prevent adjacent premature degeneration. It will take long term followup studies however to prove this. In the mean time, the justification to insert artificial cervical prostheses rests on being able to prove equivalence of outcome between fusion and prosthesis in the short term. This paper shows that the outcomes appear to be equivalent. Early statistical evidence is available for some of the outcome measures at early post op followup. Further statistical power will be available when the full 60 cases are available for study and this may give further weight to the hypothesis of equivalence of outcome

INTRODUCTION: A prospective, randomised, controlled study has been conducted to compare the clinical outcomes of patients treated with an Artificial Cervical Disc to patients who receive fusion after cervical discectomy for the treatment of primary cervical disc disease. It is hypothesised that maintenance of motion after anterior cervical discectomy will prevent the high rate of adjacent level premature degeneration. The primary purpose of the study is to prove equivalence (non inferiority) of outcome of the disc prosthesis in the short term compared with fusion. METHODS: In four centres, 60 patients with primary, single level cervical disc disease producing radiculopathy and/or myelopathy are randomised prospectively to receive anterior cervical discectomy with either fusion or artificial cervical disc placement. The patients are evaluated with pre- and post-operative serial flexion-extension cervical X-rays at six weeks, three, six, 12, and 24 months. At the same intervals, the patients have pre- and post-operative neck disability indexes, visual pain analogue scales, European myelopathy scores, SF-36 general health scores, and neurological status examinations assessing the patient’s reflex, motor and sensory function. RESULTS: Data are presented for the first 47 patients. At six weeks the neck disability index reduced by 36.1 for the investigational group compared to 34.8 for the fusion group. The pain score had reduced by 8.2 for the investigational group and by 9.9 for the control group. This improvement appeared to be maintained until the 12 month follow-up. In general there appeared to be a slightly better outcome for the investigational group. Both pain score and disability scores improved statistically significantly compared to the pre-operative scores (p< 0.001 all comparisons). Analysis of non inferiority of outcome for the investigational group using ANCOVA with the pre-operative score as the covariate and a non inferiority margin of five points showed statistical significance at six and 12 weeks for Neck disability index. Operative time appeared slightly less (2.3 hours) for the investigational group compared to the fusion group (2.5 hours). Blood loss also appeared higher in the fusion group (165 mls compared to 91 mls). Hospital stay was equivalent (2.8 days and 2.9 days). DISCUSSION: Anterior cervical discectomy and fusion has a good short term outcome though there is a high incidence of failure at adjacent levels over time. It is hypothesised that the maintenance of motion of a segment will prevent adjacent premature degeneration. It will take long term follow-up studies however to prove this. In the meantime, the justification to insert artificial cervical prostheses rests on being able to prove equivalence of outcome between fusion and prosthesis in the short term. This paper shows that the outcomes appear to be equivalent. Early statistical evidence is available for some of the outcome measures at early post-operative follow-up. Further statistical power will be available when the full 60 cases are available for study and this may give further weight to the hypothesis of equivalence of outcome

Introduction: A prospective, randomized, controlled study has been conducted to compare the clinical outcomes of patients treated with an artificial cervical disc to patients who receive fusion after cervical discectomy for the treatment of primary cervical disc disease. It is hypothesized that maintenance of motion after anterior cervical discectomy will prevent the high rate of adjacent level premature degeneration. The primary purpose of the study is to prove equivalence (non inferiority) of outcome of the disc prosthesis in the short term compared with fusion. Enrolment has closed and this is a report of the data with 50 cases with 6 month follow-up and 9 cases having reached 24 month final follow-up. Methods: In four centres, 52 patients with primary, single level cervical disc disease producing radiculopathy and/or myelopathy were randomised prospectively to receive anterior cervical discectomy with either fusion or artificial cervical disc replacement. The patients were evaluated with pre- and post-operative serial flexion-extension cervical x-rays at 6 weeks, 3, 6, 12, and 24 months. At the same intervals, the patients had pre and postoperative neck disability indexes, visual pain analogue scales, European myelopathy scores, SF-36 general health scores, and neurological status examinations assessing the patient’s reflex, motor and sensory function. Results: At 6 weeks the neck disability index reduced by 34.1 for the investigational group compared to 35.2 for the fusion group. The pain score had reduced by 7.7 for the investigational group and by 9.7 for the control group. This improvement appeared to be maintained until the 12 month follow-up. The mean pain scores at 24 months were similar (4.3 and 5.6 respectively) In general there appeared to be a slightly better outcome for the investigational group, though the investigational group showed slightly less preoperative pain (p=0.091) and disability (p=0.055) than the fusion group. Both pain score and disability scores improved statistically significantly compared to the pre op scores (p< 0.001 all comparisons). Analysis of non-inferiority of outcome for the investigational group using ANCOVA with the preoperative score as the covariate and a non-inferiority margin of 5 points (5%) showed statistical significance at 12 weeks for Neck Disability Index. Discussion: Anterior cervical discectomy and fusion has a good short-term outcome though there is a high incidence of failure at adjacent levels over time. It is hypothesized that the maintenance of motion of a segment will prevent adjacent premature degeneration. It will take long term follow-up studies however to prove this. In the mean time, the justification to insert artificial cervical prostheses rests on being able to prove equivalence of outcome between fusion and prosthesis in the short term. This paper shows that the outcomes appear to be equivalent. Though there is insufficient power to prove equivalence with a clinical margin of 5%

Introduction A prospective, randomised, controlled study has been conducted to compare the clinical outcomes of patients treated with a Presige® artificial cervical disc (Medtronic Sofamor Danek, Memphis, TN) to patients who receive fusion after cervical discectomy for the treatment of primary cervical disc disease. It is hypothesized that maintenance of motion after anterior cervical discectomy will prevent the high rate of adjacent level premature degeneration. The primary purposes of the study are to (1) prove equivalence (non inferiority) of outcome of the disc prosthesis in the short term compared with fusion; and (2) to asses the ability of the prosthesis to maintain motion. Enrolment has closed and this is a report of the data with 50 cases with 6 month follow-up and 9 cases having reached 24 month final follow-up. Methods In four centres, 52 patients with primary, single level cervical disc disease producing radiculopathy and/or myelopathy were randomised prospectively to receive anterior cervical discectomy with either fusion or artificial cervical disc replacement. The patients were evaluated with pre and postoperative serial flexion-extension cervical x-rays at 6 weeks, 3, 6, 12, and 24 months. At the same intervals, the patients had pre and postoperative neck disability indexes, visual pain analogue scales, European myelopathy scores, SF-36 general health scores, and neurological status examinations assessing the patient’s reflex, motor and sensory function. Results At 6 weeks the neck disability index reduced by 34.1 for the investigational group compared to 35.2 for the fusion group. The improvement seen in the treatment groups was statistically equivalent (p < 0.05, non-inferiority margin = 10) up to the 24-month follow-up interval. The pain score had reduced by 7.7 for the investigational group and by 9.7 for the control group. Both groups improved statistically from preoperatively though statistical equivalence could not be shown. This improvement appeared to be maintained until the 12 month follow-up. Mean arm pain scores improved in both groups with statistical equivalence being demonstrated (p < 0.05, non-inferiority margin = 10). The adverse events in both groups were similar. Analysis of range motion showed a mean preoperative range of motion in the arthroplasty group of 5.9 degrees and 6.3 degrees in the fusion group. At twelve months the arthroplasty group had a mean range of motion of 5.9 degrees and the fusion group had a mean range of motion of 1.1 degrees. Discussion Anterior cervical discectomy and fusion has a good short term outcome though there is a high incidence of failure at adjacent levels over time. It is hypothesised that the maintenance of motion of a segment will prevent adjacent premature degeneration. It will take long term follow-up studies however to prove this. In the mean time, the justification to insert artificial cervical prostheses rests on being able to prove equivalence of outcome between fusion and prosthesis in the short term. This paper shows that, in the short to medium term, the clinical outcomes appear to be equivalent to fusion. And that range of motion is maintained

Aims. The aim of this study was to investigate whether the type of cervical disc herniation influences the severity of symptoms at the time of presentation, and the outcome after surgical treatment. Methods. The type and extent of disc herniation at the time of presentation in 108 patients who underwent anterior discectomy for cervical radiculopathy were analyzed on MRI, using a four-point scale. These were dichotomized into disc bulge and disc herniation groups. Clinical outcomes were evaluated using the Neck Disability Index (NDI), 36-Item Short Form Survey (SF-36), and a visual analogue scale (VAS) for pain in the neck and arm at baseline and two years postoperatively. The perceived recovery was also assessed at this time. Results. At baseline, 46 patients had a disc bulge and 62 had a herniation. There was no significant difference in the mean NDI and SF-36 between the two groups at baseline. Those in the disc bulge group had a mean NDI of 44.6 (SD 15.2) compared with 43.8 (SD 16.0) in the herniation group (p = 0.799), and a mean SF-36 of 59.2 (SD 6.9) compared with 59.4 (SD 7.7) (p = 0.895). Likewise, there was no significant difference in the incidence of disabling arm pain in the disc bulge and herniation groups (84% vs 73%; p = 0.163), and no significant difference in the incidence of disabling neck pain in the two groups (70.5% (n = 31) vs 63% (n = 39); p = 0.491). At two years after surgery, no significant difference was found in any of the clinical parameters between the two groups. Conclusion. In patients with cervical radiculopathy, the type and extent of disc herniation measured on MRI prior to surgery correlated neither to the severity of the symptoms at presentation, nor to clinical outcomes at two years postoperatively. Cite this article: Bone Joint J 2022;104-B(11):1242–1248

Aims. The aim of this study was to use diffusion tensor imaging (DTI) to investigate changes in diffusion metrics in patients with cervical spondylotic myelopathy (CSM) up to five years after decompressive surgery. We correlated these changes with clinical outcomes as scored by the Modified Japanese Orthopedic Association (mJOA) method, Neck Disability Index (NDI), and Visual Analogue Scale (VAS). Methods. We used multi-shot, high-resolution, diffusion tensor imaging (ms-DTI) in patients with cervical spondylotic myelopathy (CSM) to investigate the change in diffusion metrics and clinical outcomes up to five years after anterior cervical interbody discectomy and fusion (ACDF). High signal intensity was identified on T2-weighted imaging, along with DTI metrics such as fractional anisotropy (FA). MJOA, NDI, and VAS scores were also collected and compared at each follow-up point. Spearman correlations identified correspondence between FA and clinical outcome scores. Results. Significant differences in mJOA scores and FA values were found between preoperative and postoperative timepoints up to two years after surgery. FA at the level of maximum cord compression (MCL) preoperatively was significantly correlated with the preoperative mJOA score. FA postoperatively was also significantly correlated with the postoperative mJOA score. There was no statistical relationship between NDI and mJOA or VAS. Conclusion. ms-DTI can detect microstructural changes in affected cord segments and reflect functional improvement. Both FA values and mJOA scores showed maximum recovery two years after surgery. The DTI metrics are significantly associated with pre- and postoperative mJOA scores. DTI metrics are a more sensitive, timely, and quantifiable surrogate for evaluating patients with CSM and a potential quantifiable biomarker for spinal cord dysfunction. Cite this article: Bone Joint J 2020;102-B(9):1210–1218