An observational study of quality of motion in the aging cervical spine: sequence of segmental contributions in dynamic fluoroscopy recordings.

BACKGROUND: The term 'physiological motion of the spine' is commonly used although no proper definition exists. Previous work has revealed a consistent sequence of cervical segmental contributions in 80-90% of young healthy individuals. Age has been shown to be associated with a decreased quantity of motion. Therefore, it is of interest to study whether this sequence persists throughout aging. The aim of this prospective cohort study is to investigate if the consistent sequence of cervical segmental contributions in young asymptomatic individuals remains present in elderly asymptomatic individuals. METHODS: In this prospective cohort study, dynamic flexion to extension cinematographic recordings of the cervical spine were made in asymptomatic individuals aged 55-70 years old. Individuals without neck pain and without severe degenerative changes were included. Two recordings were made in each individual with a 2-to-4-week interval (T1 and T2). Segmental rotation of each individual segment between C4 and C7 was calculated to determine the sequence of segmental contributions. Secondary outcomes were segmental range of motion (sRoM) and sagittal alignment. RESULTS: Ten individuals, with an average age of 61 years, were included. The predefined consistent sequence of segmental contributions was found in 10% of the individuals at T1 and 0% at T2. sRoM and total range of motion (tRoM) were low in all participants. There was no statistically significant correlation between sagittal alignment, degeneration and sRoM in the respective segments, nor between cervical lordosis and tRoM. CONCLUSIONS: This study shows that aging is associated with loss of the consistent motion pattern that was observed in young asymptomatic individuals. The altered contribution of the cervical segments during extension did not appear to be correlated to the degree of degeneration or sagittal alignment. Trial registration clinicaltrials.gov NCT04222777, registered 10.01.2020.

A randomized controlled trial with extended long-term follow-up: Quality of cervical spine motion after anterior cervical discectomy (ACD) or anterior cervical discectomy with arthroplasty (ACDA).

Introduction: In previous research, a consistent sequence of segmental contributions during dynamic extension X-rays of the cervical spine was observed in 80-90% of healthy participants. Research question: To investigate whether this previously defined 'normal' sequence of segmental contributions was present in patients who underwent anterior cervical discectomy with arthroplasty (ACDA) or anterior cervical discectomy (ACD). Materials & methods: A randomized controlled trial with extended follow-up was conducted. Patients with single level cervical degenerative radiculopathy with a surgical indication were included and randomized. Dynamic X-ray recordings were made before surgery, one-year post-operative, and at long term follow-up. Results: A total of 27 patients were included, three in an ACDA pilot group and 24 were randomized to receive ACDA (N = 12) or ACD (N = 12). A total of 20 patients were available for follow-up. Preoperatively, 16.7% of patients in the ACDA group and 58.3% of patients in the ACD group showed a normal sequence. One-year post-operative, 66.7% showed a normal sequence in the ACDA group versus 30.0% in the ACD group (p = 0.036). After an average of 11-years follow-up, a normal sequence was observed in 9.1% of patients in the ACDA group and in none of the patients in the ACD group (p = 0.588). Discussion & conclusion: These findings suggest that while ACDA can restore and preserve a normal sequence of segmental contributions in the short term, this effect is not maintained in the long term. Throughout the process of ageing, not only the quantity, but also the quality of motion changes.

Low-Threshold-For-Surgery Versus Primarily-Conservative Treatment for Odontoid Fractures in the Elderly: Evaluating Practice Variation in The Netherlands.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: Odontoid fractures are the most common cervical spine fractures in the elderly. The optimal treatment remains controversial. The aim of this study was to compare results of a low-threshold-for-surgery strategy (surgery for dislocated fractures in relatively healthy patients) to a primarily-conservative strategy (for all patients). METHODS: Patient records from 5 medical centers were reviewed for patients who met the selection criteria (e.g. age ≥55 years, type II/III odontoid fractures). Demographics, fracture types/characteristics, fracture union/stability, clinical outcome and mortality were compared. The influence of age on outcome was studied (≥55-80 vs ≥80 years). RESULTS: A total of 173 patients were included: 120 treated with low-threshold-for-surgery (of which 22 primarily operated, and 23 secondarily) vs 53 treated primarily-conservative. No differences in demographics and fracture characteristics between the groups were identified. Fracture union (53% vs 43%) and fracture stability (90% vs 85%) at last follow-up did not differ between groups. The majority of patients (56%) achieved clinical improvement compared to baseline. Analysis of differences in clinical outcome between groups was infeasible due to data limitations. In both strategies, patients ≥80 years achieved worse union (64% vs 30%), worse stability (97% vs 77%), and - as to be expected - increased mortality <104 weeks (2% vs 22%). CONCLUSIONS: Union and stability rates did not differ between the treatment strategies. Advanced age (≥80 years) negatively influenced both radiological outcome and mortality. No cases of secondary neurological deficits were identified, suggesting that concerns for the consequences of under-treatment may be unjustified.

Advocating uniformity in spine surgery: a practical disease-specific guideline for trial-based economic evaluations.

OBJECTIVES: Despite the availability of general and national guidelines for the conduct and reporting of economic evaluations, there is heterogeneity in economic evolutions concerning spine surgery. This is partly the result of differing levels of adherence to the existing guidelines and the lack of disease-specific recommendations for economic evaluations. The extensive heterogeneity in study design, follow-up duration and outcome measurements limit the comparability of economic evaluations in spine surgery. This study has three objectives: (1) to create disease-specific recommendations for the design and conduct of trial-based economic evaluations in spine surgery, (2) to define recommendations for reporting economic evaluations in spine surgery as a complement to the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) 2022 checklist and (3) to discuss methodological challenges and defining the need for future research. DESIGN: A modified Delphi method according to the RAND/UCLA Appropriateness Method. SETTING: A four-step process was followed to create and validate disease-specific statements and recommendations for the conduct and reporting of trial-based economic evaluations in spine surgery. Consensus was defined as >75% agreement. PARTICIPANTS: A total of 20 experts were included in the expert group. Validation of the final recommendations was obtained in a Delphi panel, which consisted of 40 researchers in the field who were not included in the expert group. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome measure is a set of recommendations for the conduct and reporting, as a complement to the CHEERS 2022 checklist, of economic evaluations in spine surgery. RESULTS: A total of 31 recommendations are made. The Delphi panel confirmed consensus on all of the recommendations in the proposed guideline. CONCLUSION: This study provides an accessible and practical guideline for the conduct of trial-based economic evaluations in spine surgery. This disease-specific guideline is a complement to existing guidelines, and should aid in reaching uniformity and comparability.

Methodology of economic evaluations in spine surgery: a systematic review and qualitative assessment.

OBJECTIVES: The present study is a systematic review conducted as part of a methodological approach to develop evidence-based recommendations for economic evaluations in spine surgery. The aim of this systematic review is to evaluate the methodology and quality of currently available clinical cost-effectiveness studies in spine surgery. STUDY DESIGN: Systematic literature review. DATA SOURCES: PubMed, Web of Science, Embase, Cochrane, Cumulative Index to Nursing and Allied Health Literature, EconLit and The National Institute for Health Research Economic Evaluation Database were searched through 8 December 2022. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Studies were included if they met all of the following eligibility criteria: (1) spine surgery, (2) the study cost-effectiveness and (3) clinical study. Model-based studies were excluded. DATA EXTRACTION AND SYNTHESIS: The following data items were extracted and evaluated: pathology, number of participants, intervention(s), year, country, study design, time horizon, comparator(s), utility measurement, effectivity measurement, costs measured, perspective, main result and study quality. RESULTS: 130 economic evaluations were included. Seventy-four of these studies were retrospective studies. The majority of the studies had a time horizon shorter than 2 years. Utility measures varied between the EuroQol 5 dimensions and variations of the Short-Form Health Survey. Effect measures varied widely between Visual Analogue Scale for pain, Neck Disability Index, Oswestry Disability Index, reoperation rates and adverse events. All studies included direct costs from a healthcare perspective. Indirect costs were included in 47 studies. Total Consensus Health Economic Criteria scores ranged from 2 to 18, with a mean score of 12.0 over all 130 studies. CONCLUSIONS: The comparability of economic evaluations in spine surgery is extremely low due to different study designs, follow-up duration and outcome measurements such as utility, effectiveness and costs. This illustrates the need for uniformity in conducting and reporting economic evaluations in spine surgery.

Clinical adjacent segment pathology after anterior cervical discectomy, with and without fusion, for cervical degenerative disc disease: A single center retrospective cohort study with long-term follow-up.

Introduction: Clinical adjacent segment pathology (CASP) continues to be a cause of concern after anterior surgical treatment for single- or multilevel cervical degenerative disc disease (CDDD). The current literature reports inconsistent incidence rates and contended risk factors in the development of CASP. Research question: The aim is to determine the incidence of additional CASP-related surgeries after anterior cervical discectomy with fusion (ACDF) or without fusion (ACD) for CDDD. Secondary outcomes include risk factors for the development of CASP and long-term clinical outcomes. Materials & methods: This is a single-center, retrospective cohort study with a long-term follow up. Patients undergoing ACD(F) for CDDD between January 2012 and December 2019 were included. Results: A total of 601 patients were included, with an average follow-up period of 5.0 years. Most patients underwent ACDF with stand-alone cages (87.7%). CASP developed in 58 (9.7%) patients, 41 (70.7%) of which required additional adjacent level surgery. ACD significantly accelerated the development of CASP. The C2-C7 Cobb angle appeared less lordotic upon early post-operative imaging in ACDF patients that later-on developed CASP. Baseline degeneration at the index level and adjacent levels was not significantly different between patients with and without CASP. Discussion & conclusion: In this retrospective cohort, we observe a relatively low rate of additional surgery for CASP in ACDF with stand-alone cages. We suggest that surgical technique, fusion, segmental kyphosis and natural degeneration play a multifactorial role in the development of CASP. Complication rates were low and clinical outcomes were similar for all techniques used.

Research protocol: Cervical Arthroplasty Cost Effectiveness Study (CACES): economic evaluation of anterior cervical discectomy with arthroplasty (ACDA) versus anterior cervical discectomy with fusion (ACDF) in the surgical treatment of cervical degenerative disc disease - a randomized controlled trial.

INTRODUCTION: To date, there is no consensus on which anterior surgical technique is more cost-effective in treating cervical degenerative disc disease (CDDD). The most commonly used surgical treatment for patients with single- or multi-level symptomatic CDDD is anterior cervical discectomy with fusion (ACDF). However, new complaints of radiculopathy and/or myelopathy commonly develop at adjacent levels, also known as clinical adjacent segment pathology (CASP). The extent to which kinematics, surgery-induced fusion, natural history, and progression of disease play a role in the development of CASP remains unclear. Anterior cervical discectomy with arthroplasty (ACDA) is another treatment option that is thought to reduce the incidence of CASP by preserving motion in the operated segment. While ACDA is often discouraged, as the implant costs are higher while the clinical outcomes are similar to ACDF, preventing CASP might be a reason for ACDA to be a more cost-effective technique in the long term. METHODS AND ANALYSIS: In this randomized controlled trial, patients will be randomized to receive ACDF or ACDA in a 1:1 ratio. Adult patients with single- or multi-level CDDD and symptoms of radiculopathy and/or myelopathy will be included. The primary outcome is cost-effectiveness and cost-utility of both techniques from a healthcare and societal perspective. Secondary objectives are the differences in clinical and radiological outcomes between the two techniques, as well as the qualitative process surrounding anterior decompression surgery. All outcomes will be measured at baseline and every 6 months until 4 years post-surgery. DISCUSSION: High-quality evidence regarding the cost-effectiveness of both ACDA and ACDF is lacking; to date, there are no prospective trials from a societal perspective. Considering the aging of the population and the rising healthcare costs, there is an urgent need for a solid clinical cost-effectiveness trial addressing this question. TRIAL REGISTRATION: ClinicalTrials.gov NCT04623593. Registered on 29 September 2020.

A Systematic Review on Neurological Outcomes for Cervical Degenerative Myelopathy After Anterior Decompression Surgery: Motion Preservation vs Fusion.

BACKGROUND: Although it is well established that surgically treated patients with cervical degenerative myelopathy (CDM) improve irrespective of the anterior decompression technique used, no consensus exists on what technique is superior in terms of neurological recovery. A general concern exists that anterior cervical discectomy with arthroplasty (ACDA) leads to less favorable outcomes in CDM due to microtrauma caused by preserved mobility. It is remarkable that current literature mainly uses pain scores to assess clinical outcomes after anterior decompression surgery, especially considering that pain may not be the most relevant outcome for CDM. This systematic review evaluated the literature concerning neurological outcomes in patients with CDM treated with anterior decompression surgery and assessed by validated myelopathy scores. METHODS: Systematic searches were carried out in PubMed, EMBASE, Web of Science, CINAHL, and the Cochrane Library. Prospective studies were included when patients with isolated CDM were treated with anterior decompression surgery, and a validated myelopathy outcome score was used. RESULTS: A total of 11 studies were included from the 16,032 identified studies. All studies used the modified Japanese Orthopedic Association (JOA) outcome score and showed improvement for all anterior techniques. The mean improvement in anterior cervical discectomy and fusion (ACDF) was 4.80 and 3.64 for the modified JOA and JOA outcome scores, respectively. The JOA for ACDA showed a mean improvement of 5.51. The overall quality of the included articles was low to moderate according to the Cochrane tool. CONCLUSION: Neurological recovery of CDM is similar after all anterior decompression techniques, including ACDA when compared with ACDF. CLINICAL RELEVANCE: The current literature gives no reason to dissuade the use of ACDA in cervical myelopathy.

Evidence-based recommendations for economic evaluations in spine surgery: study protocol for a Delphi consensus.

INTRODUCTION: Considering the rising global healthcare expenses, economic evaluations are more important than ever. Even though the number of studies regarding costs and cost-effectiveness is increasing, the quality of these studies remains relatively low. This is mainly caused by abundant heterogeneity in methods used for determining, calculating and reporting cost data, despite current general guidelines for the conduct of economic evaluations. Disease-specific recommendations for the conduct of economic evaluations in the field of spine surgery, as complement to existing general guidelines, will ameliorate overall research quality, comparability and interpretability and thus, the overall quality. We aim to provide expert-based recommendations for the design, conduct, and reporting of economic evaluations in spine surgery. METHODS AND ANALYSIS: A modified Delphi study will be conducted to formulate expert-based recommendations. The following steps will be taken:(1) The conduct of a systematic review to identify relevant publications and identify relevant authors. Formation of an expert group and a Delphi-panel. (2) Drafting of statements based on articles included in the systematic literature review. Validation of drafted statements by the expert group. Step 2 can be repeated up to three times, statements can be discarded and adjusted in these rounds. Statements with more than 75% agreement will be accepted as consensus statements. (3) Validation of statements by the Delphi-panel. (4) Final recommendations. ETHICS AND DISSEMINATION: The underlying work is based on existing literature and published data and does not include participation of patients, and thus does not require ethical review approval. The final recommendations are intended for (clinical) researchers in the field of cost-effectiveness in spine surgery. The Delphi method ensures that the final output reflects the opinions of international participants and gives insight in the adherence level to the recommendations. The aim is to reach uniformity in design, conduct and reporting of these studies, as is currently lacking. This will provide a solid basis to determine cost-effectiveness of spine surgeries and consequently aid to limit the rising healthcare costs. The findings of this study and the final recommendations will be disseminated in conferences and seminars and will be published in an international peer-reviewed journal.

Ossification of the posterior longitudinal ligament at the craniocervical junction presenting with Brown-Séquard syndrome: A case report.

BACKGROUND: Several case reports about spinal cord compression due to hyperostosis at the craniocervical junction are available. However, compression at C1-C2 solely due to ossification of the posterior longitudinal ligament (OPLL) is rare. CASE DESCRIPTION: A 50-year-old Asian male, with a history of lumbar spinal canal stenosis, presented with a progressive quadriparesis within 3 months. Imaging showed central OPLL at the C1-C2 level contributing to severe spinal cord compression. The patient improved neurologically after a C1-C2 laminectomy. CONCLUSION: A patient presented with a progressive Brown-Séquard syndrome due to OPLL at the craniocervical junction (C1-C2 level) and improved following a decompressive laminectomy.

Effect of Anesthesia on Microelectrode Recordings during Deep Brain Stimulation Surgery in Tourette Syndrome Patients.

BACKGROUND: Deep brain stimulation (DBS) is an accepted treatment for patients with medication-resistant Tourette syndrome (TS). Sedation is commonly required during electrode implantation to attenuate anxiety, pain, and severe tics. Anesthetic agents potentially impair the quality of microelectrode recordings (MER). Little is known about the effect of these anesthetics on MER in patients with TS. We describe our experience with different sedative regimens on MER and tic severity in patients with TS. METHODS: The clinical records of all TS patients who underwent DBS surgery between 2010 and 2018 were reviewed. Demographic data, stimulation targets, anesthetic agents, perioperative complications, and MER from each hemisphere were collected and analyzed. Single-unit activity was identified by filtering spiking activity from broadband MER data and principal component analysis with K-means clustering. Vocal and motor tics which caused artifacts in the MER data were manually selected using visual and auditory inspection. RESULTS: Six patients underwent bilateral DBS electrode implantation. In all patients, the target was the anterior internal globus pallidus. Patient comfort and hemodynamic and respiratory stability were maintained with conscious sedation with one or more of the following anesthetic drugs: propofol, midazolam, remifentanil, clonidine, and dexmedetomidine. Good quality MER and clinical testing were obtained in 9 hemispheres of 6 patients. In 3 patients, MER quality was poor on one side. CONCLUSION: Cautiously applied sedative drugs can provide patient comfort, hemodynamic and respiratory stability, and suppress severe tics, with minimal interference with MER.

Ethics of Deep Brain Stimulation in Adolescent Patients with Refractory Tourette Syndrome: a Systematic Review and Two Case Discussions.

INTRODUCTION: Tourette Syndrome (TS) is a childhood onset disorder characterized by vocal and motor tics and often remits spontaneously during adolescence. For treatment refractory patients, Deep Brain Stimulation (DBS) may be considered. METHODS AND RESULTS: We discuss ethical problems encountered in two adolescent TS patients treated with DBS and systematically review the literature on the topic. Following surgery one patient experienced side effects without sufficient therapeutic effects and the stimulator was turned off. After a second series of behavioural treatment, he experienced a tic reduction of more than 50%. The second patient went through a period of behavioural disturbances that interfered with optimal programming, but eventually experienced a 70% tic reduction. Sixteen DBS surgeries in adolescent TS patients have been reported, none of which pays attention to ethical aspects. DISCUSSION: Specific ethical issues arise in adolescent TS patients undergoing DBS relating both to clinical practice as well as to research. Attention should be paid to selecting patients fairly, thorough examination and weighing of risks and benefits, protecting the health of children and adolescents receiving DBS, special issues concerning patient's autonomy, and the normative impact of quality of life. In research, registration of all TS cases in a central database covering a range of standardized information will facilitate further development of DBS for this indication. CONCLUSION: Clinical practice should be accompanied by ongoing ethical reflection, preferably covering not only theoretical thought but providing also insights in the views and perspectives of those concerned, that is patients, family members and professionals.

Thalamic Deep Brain Stimulation for Refractory Tourette Syndrome: Clinical Evidence for Increasing Disbalance of Therapeutic Effects and Side Effects at Long-Term Follow-Up.

OBJECTIVE: Thalamic deep brain stimulation (DBS) is effective in reducing tics in patients with refractory Tourette syndrome at the short-term. Here, we report on the long-term outcome. MATERIALS AND METHODS: Seven patients underwent bilateral DBS between 2001 and 2008. The target was the centromedian nucleus, substantia periventricularis and nucleus ventro-oralis internus cross point of the thalamus. The effect on tics and side effects were evaluated with a variable follow-up duration of 12 to 78 months. RESULTS: Patient 1 and 2 showed good tic improvements of 81.6% (60 months) and 50% (36 months), respectively. However, side effects like reducing levels of energy and visual disturbances increased. In patient 1, the target was changed to the anterior part of the internal pallidum and patient 2 switched the stimulator permanently off. Patient 3 experiences still satisfying results with a tic improvement of 88.9% (78 months). Patient 4 and 7 showed minor tic improvements of 34% (16 months) and 9% (60 months), respectively. In both patients side effects became more severe and the target was changed to the anterior part of the internal pallidum. Patient 5 showed a tic improvement of 27.5% (12 months) and went abroad for stimulation of the external globus pallidus. Patient 6 developed cerebellar atrophy. He experienced several nonstimulation related side effects and turned the stimulator off. CONCLUSIONS: There seems to be an increasing disbalance of therapeutic effects and side effects at long-term follow-up, often leading to either switching the stimulator off or new surgery with a different neuro-anatomic target.

Tonic and phasic changes in anteromedial globus pallidus activity in Tourette syndrome.

BACKGROUND: Tourette syndrome is a hyperkinetic neurodevelopmental disorder characterized by tics. OBJECTIVE: Assess the neuronal changes in the associative/limbic GP associated with Tourette syndrome. METHODS: Neurophysiological recordings were performed from the anterior (associative/limbic) GPe and GPi of 8 awake patients during DBS electrode implantation surgeries. RESULTS: The baseline firing rate of the neurons was low in a state-dependent manner in both segments of the GP. Tic-dependent transient rate changes were found in the activity of individual neurons of both segments around the time of the tic. Neither oscillatory activity of individual neurons nor correlations in their interactions were observed. CONCLUSIONS: The results demonstrate the involvement of the associative/limbic pathway in the underlying pathophysiology of Tourette syndrome and point to tonic and phasic modulations of basal ganglia output as a key mechanisms underlying the abnormal state of the disorder and the expression of individual tics, respectively. © 2017 International Parkinson and Movement Disorder Society.