Adverse Events After Cervical Spinal Manipulation - A Systematic Review and Meta-Analysis of Randomized Clinical Trials.

BACKGROUND: Cervical manipulations are widely used by physiotherapists, chiropractors, osteopaths, and medical doctors for musculoskeletal dysfunctions like neck pain and cervicogenic headache. The use of cervical manipulation remains controversial, since it is often considered to pose a risk for not only benign adverse events (AEs), such as aggravation of pain or muscle soreness, but also severe AEs such as strokes in the vertebrobasilar or carotid artery following dissections. Studies finding an association between cervical manipulation and serious AEs such as artery dissections are mainly case control studies or case reports. These study designs are not appropriate for investigating incidences and therefore do not imply causal relationships. Randomized controlled trials (RCTs) are considered the gold standard study designs for assessing the unconfounded effects of benefits and harms, such as AEs, associated with therapies. OBJECTIVE: Due to the unclear risk level of AEs associated with high-velocity, low-amplitude (HVLA) cervical manipulation, the aim of this study was to extract available information from RCTs and thereby synthesize the comparative risk of AEs following cervical manipulation to that of various control interventions. STUDY DESIGN: Systematic review and meta-analysis. METHODS: A systematic literature search was conducted in the PubMed and Cochrane databases. This search included RCTs in which cervical HVLA manipulations were applied and AEs were reported. Two independent reviewers performed the study selection, the methodological quality assessment, and the GRADE approach. Incidence rate ratios (IRR) were calculated. The study quality was assessed by using the risk of bias 2 (RoB-2) tool, and the certainty of evidence was determined by using the GRADE approach. RESULTS: Fourteen articles were included in the systematic review and meta-analysis. The pooled IRR indicates no statistically significant differences between the manipulation and control groups. All the reported AEs were classified as mild, and none of the AEs reported were serious or moderate. LIMITATIONS: The search strategy was limited to literature in English or German. Furthermore, selection bias may have occurred, since only PubMed and Cochrane were used as databases, and searching was done by hand. RCTs had to be excluded if the results did not indicate the group in which the AEs occurred. A mandatory criterion for inclusion in the meta-analysis was a quantitative reproduction of the frequencies of AEs that could be attributed to specific interventions. CONCLUSION: In summary, HVLA manipulation does not impose an increased risk of mild or moderate AEs compared to various control interventions. However, these results must be interpreted with caution, since RCTs are not appropriate for detecting the rare serious AEs. In addition, future RCTs should follow a standardized protocol for reporting AEs in clinical trials.

Association between chiropractic spinal manipulation and cauda equina syndrome in adults with low back pain: Retrospective cohort study of US academic health centers.

BACKGROUND: Cauda equina syndrome (CES) is a lumbosacral surgical emergency that has been associated with chiropractic spinal manipulation (CSM) in case reports. However, identifying if there is a potential causal effect is complicated by the heightened incidence of CES among those with low back pain (LBP). The study hypothesis was that there would be no increase in the risk of CES in adults with LBP following CSM compared to a propensity-matched cohort following physical therapy (PT) evaluation without spinal manipulation over a three-month follow-up period. METHODS: A query of a United States network (TriNetX, Inc.) was conducted, searching health records of more than 107 million patients attending academic health centers, yielding data ranging from 20 years prior to the search date (July 30, 2023). Patients aged 18 or older with LBP were included, excluding those with pre-existing CES, incontinence, or serious pathology that may cause CES. Patients were divided into two cohorts: (1) LBP patients receiving CSM or (2) LBP patients receiving PT evaluation without spinal manipulation. Propensity score matching controlled for confounding variables associated with CES. RESULTS: 67,220 patients per cohort (mean age 51 years) remained after propensity matching. CES incidence was 0.07% (95% confidence intervals [CI]: 0.05-0.09%) in the CSM cohort compared to 0.11% (95% CI: 0.09-0.14%) in the PT evaluation cohort, yielding a risk ratio and 95% CI of 0.60 (0.42-0.86; p = .0052). Both cohorts showed a higher rate of CES during the first two weeks of follow-up. CONCLUSIONS: These findings suggest that CSM is not a risk factor for CES. Considering prior epidemiologic evidence, patients with LBP may have an elevated risk of CES independent of treatment. These findings warrant further corroboration. In the meantime, clinicians should be vigilant to identify LBP patients with CES and promptly refer them for surgical evaluation.

Dosing of lumbar spinal manipulative therapy and its association with escalated spine care: A cohort study of insurance claims.

OBJECTIVE: The objective of this study was to evaluate the relationship between three distinct spinal manipulative therapy dose groups and escalated spine care by analyzing insurance claims from a cohort of patients with low back pain. METHODS: We compared three distinct spinal manipulative therapy dose groups (low = 1 SMT visits, moderate = 2-12 SMT visits, high = 13+ SMT visits), to a control group (no spinal manipulative therapy) regarding the outcome of escalated spine care. Escalated spine care procedures include imaging studies, injection procedures, emergency department visits, surgery, and opioid medication use. Propensity score matching was performed to address treatment selection bias. Modified Poisson regression modeling was used to estimate the relative risk of spine care escalation among three spinal manipulative therapy doses, adjusting for age, sex, retrospective risk score and claim count. RESULTS: 83,025 claims were categorized into 11,114 unique low back pain episodes; 8,137 claims had 0 spinal manipulative therapy visits, with the remaining episodes classified as low dose (n = 404), moderate dose (n = 1,763) or high dose (n = 810). After propensity score matching, 5,348 episodes remained; 2,454 had 0 spinal manipulative therapy visits with the remaining episodes classified as low dose (n = 404), moderate dose (n = 1,761), or high dose (n = 729). The estimated relative risk (vs no spinal manipulative therapy) for any escalated spine care was 0.45 (95% confidence interval 0.38, 0.55, p <0.001), 0.58 (95% confidence interval 0.53, 0.63, p <0.001), and 1.03 (95% confidence interval 0.95, 1.13, p = 0.461) for low, moderate, and high dose spinal manipulative therapy groups, respectively. CONCLUSIONS: For claims associated with initial episodes of low back pain, low and moderate dose spinal manipulative therapy groups were associated with a 55% and 42% reduction, respectively, in the relative risk of any escalated spine care.

Benefits and Harms of Spinal Manipulative Therapy for Treating Recent and Persistent Nonspecific Neck Pain: A Systematic Review With Meta-analysis.

OBJECTIVE: We aimed to estimate the benefits and harms of cervical spinal manipulative therapy (SMT) for treating neck pain. DESIGN: Intervention systematic review with meta-analysis of randomized controlled trials (RCTs). LITERATURE SEARCH: We searched the MEDLINE, Cochrane CENTRAL, Embase, CINAHL, PEDro, Chiropractic Literature Index bibliographic databases, and grey literature sources, up to June 6, 2022. STUDY SELECTION CRITERIA: RCTs evaluating SMT compared to guideline-recommended and nonrecommended interventions, sham SMT, and no intervention for adults with neck pain were eligible for our systematic review. Prespecified outcomes included pain, range of motion, disability, health-related quality of life. DATA SYNTHESIS: Random-effects meta-analysis for clinically homogenous RCTs at short-term and long-term outcomes. Risk of bias was assessed using the Cochrane Risk of Bias 2.0 Tool. We used the Grading of Recommendations, Assessment, Development, and Evaluations approach to judge the certainty of evidence. RESULTS: We included 28 RCTs. There was very low to low certainty evidence that SMT was more effective than recommended interventions for improving pain at short term (standardized mean difference [SMD], 0.66; 95% confidence interval [CI]: 0.35, 0.97) and long term (SMD, 0.73; 95% CI: 0.31, 1.16), and for reducing disability at short-term (SMD, 0.95; 95% CI: 0.48, 1.42) and long term (SMD, 0.65; 95% CI: 0.23, 1.06). Transient side effects only were found (eg, muscle soreness). CONCLUSION: There was very low certainty evidence supporting cervical SMT as an intervention to reduce pain and improve disability in people with neck pain. J Orthop Sports Phys Ther 2023;53(9):510-528. Epub: 10 August 2023. doi:10.2519/jospt.2023.11708.

The association between cervical artery dissection and spinal manipulation among US adults.

PURPOSE: Cervical artery dissection (CeAD), which includes both vertebral artery dissection (VAD) and carotid artery dissection (CAD), is the most serious safety concern associated with cervical spinal manipulation (CSM). We evaluated the association between CSM and CeAD among US adults. METHODS: Through analysis of health claims data, we employed a case-control study with matched controls, a case-control design in which controls were diagnosed with ischemic stroke, and a case-crossover design in which recent exposures were compared to exposures in the same case that occurred 6-7 months earlier. We evaluated the association between CeAD and the 3-level exposure, CSM versus office visit for medical evaluation and management (E&M) versus neither, with E&M set as the referent group. RESULTS: We identified 2337 VAD cases and 2916 CAD cases. Compared to population controls, VAD cases were 0.17 (95% CI 0.09 to 0.32) times as likely to have received CSM in the previous week as compared to E&M. In other words, E&M was about 5 times more likely than CSM in the previous week in cases, relative to controls. CSM was 2.53 (95% CI 1.71 to 3.68) times as likely as E&M in the previous week among individuals with VAD than among individuals experiencing a stroke without CeAD. In the case-crossover study, CSM was 0.38 (95% CI 0.15 to 0.91) times as likely as E&M in the week before a VAD, relative to 6 months earlier. In other words, E&M was approximately 3 times more likely than CSM in the previous week in cases, relative to controls. Results for the 14-day and 30-day timeframes were similar to those at one week. CONCLUSION: Among privately insured US adults, the overall risk of CeAD is very low. Prior receipt of CSM was more likely than E&M among VAD patients as compared to stroke patients. However, for CAD patients as compared to stroke patients, as well as for both VAD and CAD patients in comparison with population controls and in case-crossover analysis, prior receipt of E&M was more likely than CSM.

Reporting of adverse events associated with spinal manipulation in randomised clinical trials: an updated systematic review.

OBJECTIVES: To describe if there has been a change in the reporting of adverse events associated with spinal manipulation in randomised clinical trials (RCTs) since 2016. DESIGN: A systematic literature review. DATA SOURCES: Databases were searched from March 2016 to May 2022: MEDLINE (Ovid), Embase, CINAHL, ICL, PEDro and Cochrane Library. The following search terms and their derivatives were adapted for each platform: spinal manipulation; chiropractic; osteopathy; physiotherapy; naprapathy; medical manipulation and clinical trial. METHODS: Domains of interest (pertaining to adverse events) included: completeness and location of reporting; nomenclature and description; spinal location and practitioner delivering manipulation; methodological quality of the studies and details of the publishing journal. Frequencies and proportions of studies reporting on each of these domains were calculated. Univariable and multivariable logistic regression models were fitted to examine the effect of potential predictors on the likelihood of studies reporting on adverse events. RESULTS: There were 5399 records identified by the electronic searches, of which 154 (2.9%) were included in the analysis. Of these, 94 (61.0%) reported on adverse events with only 23.4% providing an explicit description of what constituted an adverse event. Reporting of adverse events in the abstract has increased (n=29, 30.9%) while reporting in the results section has decreased (n=83, 88.3%) over the past 6 years. Spinal manipulation was delivered to 7518 participants in the included studies. No serious adverse events were reported in any of these studies. CONCLUSIONS: While the current level of reporting of adverse events associated with spinal manipulation in RCTs has increased since our 2016 publication on the same topic, the level remains low and inconsistent with established standards. As such, it is imperative for authors, journal editors and administrators of clinical trial registries to ensure there is more balanced reporting of both benefits and harms in RCTs involving spinal manipulation.

Mechanisms of chiropractic spinal manipulative therapy for patients with chronic primary low back pain: protocol for a mechanistic randomised placebo-controlled trial.

INTRODUCTION: Chronic low back pain (CLBP) is a highly prevalent and disabling condition. Identifying subgroups of patients afflicted with CLBP is a current research priority, for which a classification system based on pain mechanisms was proposed. Spinal manipulative therapy (SMT) is recommended for the management of CLBP. Yet, little data are available regarding its mechanisms of action, making it difficult to match this intervention to the patients who may benefit the most. It was suggested that SMT may influence mechanisms associated with central sensitisation. Therefore, classifying patients with CLBP according to central sensitisation mechanisms may help predict their response to SMT. METHODS AND ANALYSIS: This protocol describes a randomised placebo-controlled trial aiming to examine which variables linked to central sensitisation may help predict the clinical response to SMT in a cohort of patients with CLBP. One hundred patients with chronic primary low back pain will be randomised to receive 12 sessions of SMT or placebo SMT over a 4-week period. Pain intensity and disability will be assessed as primary outcomes after completing the 4-week treatment (primary endpoint), and at 4-week and 12-week follow-ups. Baseline values of two pain questionnaires, lumbar pressure pain thresholds, concentrations of an inflammatory cytokine and expectations of pain relief will be entered as predictors of the response to SMT in a multiple regression model. Changes in these variables after treatment will be used in a second multiple regression model. The reference values of these predictors will be measured from 50 age and sex-matched healthy controls to allow interpretation of values in patients. Mixed analyses of variance will also be conducted to compare the primary outcomes and the predictors between groups (SMT vs placebo) over time (baseline vs post-treatment). ETHICS AND DISSEMINATION: Ethical approval was granted by the Fundación Jiménez Díaz Clinical Research Ethics Committee. TRIAL REGISTRATION NUMBER: NCT05162924.

Spinal manipulation and adverse event reporting in the pregnant patient limits estimation of relative risk: a narrative review.

OBJECTIVE: To describe variability in spinal manipulation technique details and adverse event (AE) documentation of spinal manipulation during pregnancy. METHODS: Five databases were searched for peer-reviewed investigations of spinal manipulation during pregnancy. Criteria for inclusion was as follows: high velocity, low amplitude thrust manipulation performed, subjects pregnant during manipulation, and English language. Studies were excluded when participants were not currently pregnant, and when the manipulation performed was not high-velocity, low-amplitude thrust. Data extraction included study design, number of participants, gestational age, spinal region, number of manipulations, manipulation technique details, profession of manipulator, AE reporting (Yes vs. No), type, and number of AE. RESULTS: Out of 18 studies included in the review, only three provide details of the spinal manipulation technique. The reported variables include patient position, practitioner position, and direction of thrust. Fourteen studies documented AE; however, only seven provide AE details. DISCUSSION: Reporting of spinal manipulation techniques and AE during pregnancy were inconsistent. Replication of methods in future investigations is limited without more detailed documentation of manipulation techniques performed. Furthermore, determining the relative risk and safety of spinal manipulation during pregnancy is not possible without more detailed reporting of AE. Due to these inconsistencies, a checklist is proposed for standardized reporting of spinal manipulation techniques and AE. With more consistent reporting of these parameters, results of future investigations may allow for more definitive and generalizable safety recommendations on spinal manipulation during pregnancy.

Identifying Patient Characteristics Associated With the Occurrence of Post Treatment Non-serious Adverse Events After Cervical Spine Manual Therapy Treatment in Patients With Neck Pain.

OBJECTIVES: To compare prevalence rates of serious and non-serious adverse events after manipulation and mobilization and to identify risk factors of serious and non-serious adverse events following 4 types of manual therapy treatment in patients with neck pain. DESIGN: A prospective cohort study in primary care manual therapy practice. PARTICIPANTS: Patients with neck pain (N=686) provided data on adverse events after 1014 manipulation treatments, 829 mobilization treatments, 437 combined manipulation and mobilization treatments, and 891 treatments consisting of "other treatment modality". INTERVENTIONS: Usual care manual therapy. MAIN OUTCOME MEASURES: A chi-square test was performed to explore differences in prevalence rates. Logistic regression analysis was performed within the 4 treatment groups. A priori we defined associations between patient-characteristics and adverse events of odds ratio (OR)>2 or OR<0.5 as clinically relevant. RESULTS: No serious adverse events, such as cervical artery dissection or stroke, were reported. With regard to non-serious adverse events, we found that these are common after manual therapy treatment: prevalence rates are ranging from 0.3% to 64.7%. We found a statistically significant difference between the 4 types of treatments, detrimental to mobilization treatment. Logistic regression analysis resulted in 3 main predictors related to non-serious adverse events after manual therapy treatment: smoking (OR ranges from 2.10 [95% confidence interval [CI] 1.37-3.11] to 3.33 [95% CI 1.83-5.93]), the presence of comorbidity (OR ranges from 2.32 [95% CI 1.22-4.44] to 3.88 [95% CI 1.62-9.26]), and female sex (OR ranges from 0.22 [95% CI 0.11-0.46] to 0.49 [95% CI 0.28-0.86]). CONCLUSION: There is a significant difference in the occurrence of non-serious adverse events after mobilization compared with manipulation or a combination of manipulation and mobilization. Non-serious adverse events in manual therapy practice are common and are associated with smoking and the presence of comorbidity. In addition, women are more likely to report non-serious adverse events.

Association between cervical artery dissection and spinal manipulative therapy -a medicare claims analysis.

BACKGROUND: Cervical artery dissection and subsequent ischemic stroke is the most serious safety concern associated with cervical spinal manipulation. METHODS: We evaluated the association between cervical spinal manipulation and cervical artery dissection among older Medicare beneficiaries in the United States. We employed case-control and case-crossover designs in the analysis of claims data for individuals aged 65+, continuously enrolled in Medicare Part A (covering hospitalizations) and Part B (covering outpatient encounters) for at least two consecutive years during 2007-2015. The primary exposure was cervical spinal manipulation; the secondary exposure was a clinical encounter for evaluation and management for neck pain or headache. We created a 3-level categorical variable, (1) any cervical spinal manipulation, 2) evaluation and management but no cervical spinal manipulation and (3) neither cervical spinal manipulation nor evaluation and management. The primary outcomes were occurrence of cervical artery dissection, either (1) vertebral artery dissection or (2) carotid artery dissection. The cases had a new primary diagnosis on at least one inpatient hospital claim or primary/secondary diagnosis for outpatient claims on at least two separate days. Cases were compared to 3 different control groups: (1) matched population controls having at least one claim in the same year as the case; (2) ischemic stroke controls without cervical artery dissection; and (3) case-crossover analysis comparing cases to themselves in the time period 6-7 months prior to their cervical artery dissection. We made each comparison across three different time frames: up to (1) 7 days; (2) 14 days; and (3) 30 days prior to index event. RESULTS: The odds of cervical spinal manipulation versus evaluation and management did not significantly differ between vertebral artery dissection cases and any of the control groups at any of the timepoints (ORs 0.84 to 1.88; p > 0.05). Results for carotid artery dissection cases were similar. CONCLUSION: Among Medicare beneficiaries aged 65 and older who received cervical spinal manipulation, the risk of cervical artery dissection is no greater than that among control groups.

Chiropractic Management of Neck Pain Complicated by Symptomatic Vertebral Artery Stenosis and Dizziness.

BACKGROUND Vertebrobasilar insufficiency (VBI) is most often caused by vertebrobasilar atherosclerosis, often presenting with dizziness and occasionally neck pain. Little research or guidelines regarding management of neck pain in affected patients exists. CASE REPORT A 62-year-old male hypertensive smoker presented to a chiropractor with a 13-year history of insidious-onset neck pain, dizziness, and occipital headache with a Dizziness Handicap Inventory (DHI) of 52%. The patient had known VBI, caused by bilateral vertebral artery plaques, and cervical spondylosis, and was treated with multiple cardiovascular medications. The chiropractor referred patient to a neurosurgeon, who cleared him to receive manual therapies provided manual-thrust cervical spinal manipulative therapy (SMT) was not performed. The chiropractor administered thoracic SMT and cervicothoracic soft tissue manipulation. The neck pain and dizziness mostly resolved by 1 month. At 1-year follow-up, DHI was 0%; at 2 years it was 8%. A literature search revealed 4 cases in which a chiropractor used manual therapies for a patient with VBI. Including the present case, all patients had neck pain, 60% had dizziness, and all were treated with SMT either avoiding manual cervical manipulation altogether or modifying it to avoid or limit cervical rotation, yielding positive outcomes. CONCLUSIONS The present and previous cases provide limited evidence that some carefully considered chiropractic manual therapies can afford patients with VBI relief from concurrent neck pain and possibly dizziness. Given the paucity of research, cervical SMT cannot be recommended in such patients. These findings do not apply to vertebral artery dissection, for which SMT is an absolute contraindication.

Definition and classification for adverse events following spinal and peripheral joint manipulation and mobilization: A scoping review.

INTRODUCTION: Spinal and peripheral joint manipulation and mobilization are interventions used by many healthcare providers to manage musculoskeletal conditions. Although there are many reports of adverse events (or undesirable outcomes) following such interventions, there is no common definition for an adverse event or clarity on any severity classification. This impedes advances of patient safety initiatives and practice. This scoping review mapped the evidence of adverse event definitions and classification systems following spinal and peripheral joint manipulation and mobilization for musculoskeletal conditions in adults. METHODS: An electronic search of the following databases was performed from inception to February 2021: MEDLINE, EMBASE, CINAHL, Scopus, AMED, ICL, PEDro, Cochrane Library, Open Grey and Open Theses and Dissertations. Studies including adults (18 to 65 years old) with a musculoskeletal condition receiving spinal or peripheral joint manipulation or mobilization and providing an adverse event definition and/or classification were included. All study designs of peer-reviewed publications were considered. Data from included studies were charted using a standardized data extraction form and synthesised using narrative analysis. RESULTS: From 8248 identified studies, 98 were included in the final synthesis. A direct definition for an adverse event and/or classification system was provided in 69 studies, while 29 provided an indirect definition and/or classification system. The most common descriptors to define an adverse event were causality, symptom severity, onset and duration. Twenty-three studies that provided a classification system described only the end anchors (e.g., mild/minor and/or serious) of the classification while 26 described multiple categories (e.g., moderate, severe). CONCLUSION: A vast array of terms, definition and classification systems were identified. There is no one common definition or classification for adverse events following spinal and peripheral joint manipulation and mobilization. Findings support the urgent need for consensus on the terms, definition and classification system for adverse events related to these interventions.

Immediate effects of spinal manipulation on painful sensitivity and postural stability in patients with chronic nonspecific low back pain: study protocol for a controlled randomised clinical trial.

BACKGROUND: Low back pain is one of the main public health concerns. Chronic low back pain (cLBP) reduces functional capacity and affects postural stability. Although health professionals widely use spinal manipulation, its immediate effect on painful sensitivity and postural stability is lacking. This study aims to verify the immediate effects of lumbar spinal manipulation on the pressure pain threshold and postural stability in individuals with cLBP. METHODS: A two-arm, placebo-controlled clinical trial with parallel groups and examiner-blinded will be conducted with 80 participants with cLBP from an outpatient physical therapy department, randomly allocated at a 1:1 distribution. The experimental group will receive a lumbar spinal manipulation technique, and the placebo group will receive a simulated lumbar spinal manipulation. Both groups will receive one session of treatment and will be evaluated before and immediately after the intervention. The primary outcomes will be the pressure pain threshold and postural stability. Pain intensity and patient's expectation will be assessed as a secondary outcome. The pressure pain threshold will be assessed using a pressure algometer in 6 different anatomical regions. The evaluation of postural stability will be performed in a baropodometry exam by displacing the centre of pressure. The pain intensity will be measured using the Numeric Pain Rating Scale. A Likert scale will be used for the patient's expectation about the treatment. A two-way analysis of variance will compare the effect of the interventions between groups. DISCUSSION: This study will provide insights regarding the immediate effects of spinal manipulation in patients with cLBP against a simulated spinal manipulation using objective outcomes and considering patients' expectations regarding the treatment. TRIAL REGISTRATION: Brazilian Registry of Clinical Trials RBR-3ksq2c . Registered on 13 July 2020.

Clinical decision-making for spinal manipulation for persistent spinal pain following lumbar surgery: a protocol for a systematic review and meta-analysis of individual participant data.

INTRODUCTION: There are limited available research and guidance regarding the use of spinal manipulative therapy (SMT) in patients with low back-related symptoms following lumbar spine surgery, a condition called persistent spinal pain syndrome type 2 (PSPS-2). This publication outlines a review protocol to identify and synthesise individual participant data (IPD) to examine associations between patient, clinical and surgical variables and SMT application in adults with PSPS-2. METHODS AND ANALYSIS: PubMed, OVID, Web of Science, Scopus, PEDro, Index to Chiropractic Literature and KoreaMed will be searched from inception to 1 January 2022 without language restrictions. Case reports, series, observational studies and cases from grey literature of adults receiving SMT for PSPS-2 will be included. Two investigators will independently screen citations, abstracts and full-text articles. A risk-of-bias assessment will be performed in duplicate to rate cases according to exposure and outcome ascertainment and data completeness. Data extraction will be performed in duplicate and missing IPD will be requested from corresponding authors. Multiple binary logistic regression will be used to identify independent predictors of the use of lumbar-SMT, lumbar-manual-thrust SMT and SMT within 1-year postsurgery. Patient, clinical and surgical variables will be summarised using descriptive statistics, while SMT-related outcomes (lumbar-SMT, lumbar-manual-thrust SMT and 1-year surgery-to-SMT interval) will be described using adjusted ORs with 95% CIs. ETHICS AND DISSEMINATION: This study was deemed not human subjects research by the University Hospitals' institutional review board. The results of this review will be disseminated at conferences and/or published in a peer-reviewed journal. PROSPERO REGISTRATION NUMBER: CRD42021250039.

Effects of cervical rotatory manipulation on the cervical spinal cord: a finite element study.

BACKGROUND: Little information is available concerning the biomechanism involved in the spinal cord injury after cervical rotatory manipulation (CRM). The primary purpose of this study was to explore the biomechanical and kinematic effects of CRM on a healthy spinal cord. METHODS: A finite element (FE) model of the basilaris cranii, C1-C7 vertebral bodies, nerve root complex and vertebral canal contents was constructed and validated against in vivo and in vitro published data. The FE model simulated CRM in the flexion, extension and neutral positions. The stress distribution, forma and relative position of the spinal cord were observed. RESULTS: Lower von Mises stress was observed on the spinal cord after CRM in the flexion position. The spinal cord in CRM in the flexion and neutral positions had a lower sagittal diameter and cross-sectional area. In addition, the spinal cord was anteriorly positioned after CRM in the flexion position, while the spinal cord was posteriorly positioned after CRM in the extension and neutral positions. CONCLUSION: CRM in the flexion position is less likely to injure the spinal cord, but caution is warranted when posterior vertebral osteophytes or disc herniations exist.

Spinal manipulative therapy and cervical artery dissection: A retrospective comparison with spontaneous, traumatic, and iatrogenic etiologies at a single academic medical center.

OBJECTIVE: Cervical artery dissection (CAD) has been associated with spinal manipulative therapy (SMT). Although uncommonly reported, SMT-associated CADs hold devastating neurological consequences, warranting further exploration. We endeavored to investigate this association through the comparison of all CAD etiologies at a single academic medical center. METHODS: A retrospective chart review was conducted of patients diagnosed with CAD or transferred to our institution for primary management of CAD during the 10-year period from 2010 to 2020 (n = 578). Patients were divided into SMT-associated (within 1 month of presentation), spontaneous, traumatic, and iatrogenic cohorts. RESULTS: SMT-associated dissections represented 23/578 (4%) of all dissections and 5.9% of vertebral artery dissections specifically. These patients were generally younger than those in the spontaneous (p = .004) and iatrogenic groups (p < .001), and more often non-smokers or former smokers compared to the spontaneous (p = .009), traumatic (p = .001), and iatrogenic (p = .008) groups. Additionally, the SMT group had a higher mean low-density lipoprotein (LDL) than the spontaneous (p = .009) and traumatic (p = .003) types. SMT-associated CADs were more often vertebral and bilateral, compared to the spontaneous (p = .003; p < .001), traumatic (p = .047; p = .004), and iatrogenic (p = .002; p = .002) groups. Outcomes including infarct (p = .112), medical treatment (p = .523), intervention (p = .47), and length of stay (p = .512) were similar between the SMT and spontaneous groups. CONCLUSIONS: In this unique study comparing SMT-associated CADs with other dissection etiologies, SMT-associated CADs were uncommon and not associated with worse clinical outcomes. However, SMT-associated CADs were more likely to be bilateral and affected the vertebral arteries in young, non-smoking patients with high LDL.

Clinical Efficacy and Safety of "Three-Dimensional Balanced Manipulation" in the Treatment of Cervical Spondylotic Radiculopathy by Finite Element Analysis.

Cervical spondylotic radiculopathy (CSR) is the most commonly encountered cervical spine disorder. Cervical manipulation has been demonstrated as an effective therapy for patients. However, the mechanisms of manipulations have not been elucidated. A total of 120 cervical spondylotic radiculopathy patients were divided into the "three-dimensional balanced manipulation" treatment group (TBM group) and control group randomly. The control group was treated with traditional massage; the TBM treatment group was treated with "three-dimensional balanced manipulation" based on traditional massage. The symptoms and clinical efficacy of the patients were compared before and after treatment for one month. A three-dimensional finite element model was established. The mechanical parameters were imported to simulate TBM, and finite element analysis was performed. The results showed that the total effective rate was significantly higher in the TBM group compared with the control group. The biomechanical analysis showed the vertebral body stress was mainly distributed in the C3/4 spinous processes; the deformation mainly concentrated in the anterior processes of the C3 vertebral body. The intervertebral disc stress in the C3~C7 segment was mainly distributed in the anterior part of the C3/4 intervertebral disc, and the deformation extends to the posterior part of the C3/4 nucleus pulposus. In summary, these data are suggesting that TBM was effective in CSR treatment. The results of the finite element model and biomechanical analysis provide an important foundation for effectively avoiding iatrogenic injuries and improving the effect of TBM in the treatment of CSR patients.