Impact of malnutrition on mortality and neurological recovery of older patients with spinal cord injury.

This retrospective cohort study established malnutrition's impact on mortality and neurological recovery of older patients with cervical spinal cord injury (SCI). It included patients aged ≥ 65 years with traumatic cervical SCI treated conservatively or surgically. The Geriatric Nutritional Risk Index was calculated to assess nutritional-related risk. Overall, 789 patients (mean follow-up: 20.1 months) were examined and 47 had major nutritional-related risks on admission. One-year mortality rate, median survival time, neurological recovery, and activities of daily living (ADL) at 1 year post-injury were compared between patients with major nutrition-related risk and matched controls selected using 1:2 propensity score matching to adjust for age, pre-traumatic neurological impairment, and activity. In the Kaplan-Meier analysis, the median survival times were 44.9 and 76.5 months for patients with major nutrition-related risk and matched controls, respectively (p = 0.015). Matched controls had more individuals with a neurological improvement of American Spinal Injury Association Impairment Scale ≥ 1 grade (p = 0.039) and independence in ADL at 1 year post-injury than patients with major nutrition-related risk (p < 0.05). In conclusion, 6% of older patients with cervical SCI had major nutrition-related risks; they showed a significantly higher 1 year mortality rate, shorter survival time, poorer neurological improvement, and lower ADL at 1 year post-injury than matched controls.

Neurological recovery rate and predictive factors of incomplete AIS grade C spinal cord injury in the older aged population.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: To define the prognosis and predictive factors for neurological improvement in older patients with incomplete spinal cord injury (SCI) of American Spinal Injury Association Impairment Scale grade C (AIS-C). SETTINGS: Multi-institutions in Japan. METHODS: We included patients aged ≥65 years with traumatic SCI of AIS-C who were treated conservatively or surgically with >3 follow-up months. To identify factors related to neurological improvement, patients were divided into three groups according to their neurological status at the final follow-up, with univariate among-group comparisons of demographics, radiographic, and therapeutic factors. Significant variables were included in the multivariate logistic regression analysis. RESULTS: Overall, 296 older patients with SCI of AIS-C on admission were identified (average age: 75.2 years, average follow-up: 18.7 months). Among them, 190 (64.2%) patients improved to AIS-D and 21 (7.1%) patients improved to AIS-E at final follow-up. There were significant among-group differences in age (p = 0.026), body mass index (p = 0.007), status of pre-traumatic activities of daily living (ADL) (p = 0.037), and serum albumin concentrations (p = 0.011). Logistic regression analysis showed no significant differences in variables in the stratified group of patients who improved to AIS-D. Meanwhile, serum albumin was a significant variable in patients who improved to AIS-E (p = 0.026; OR: 6.20, pre-traumatic ADL was omitted due to data skewness). CONCLUSIONS: Most older patients with incomplete AIS-C SCI demonstrated at least 1 grade of neurological improvement. However, <10% of patients achieved complete recovery. Key predictors of complete recovery were high serum albumin levels on admission and independent pre-traumatic ADL. SPONSORSHIP: No funding was received for this study.

Early Versus Delayed Surgery for Elderly Traumatic Cervical Spinal Injury: A Nationwide Multicenter Study in Japan.

STUDY DESIGN: Retrospective multicenter study. OBJECTIVES: The effectiveness of early surgery for cervical spinal injury (CSI) has been demonstrated. However, whether early surgery improves outcomes in the elderly remains unclear. This study investigated whether early surgery for CSI in elderly affects complication rates and neurological outcomes. METHODS: This retrospective multicenter study included 462 patients. We included patients with traumatic acute cervical spinal cord injury aged ≥65 years who were treated surgically, whereas patients with American Spinal Injury Association (ASIA) Impairment Scale E, those with unknown operative procedures, and those waiting for surgery for >1 month were excluded. The minimum follow-up period was 6 months. Sixty-five patients (early group, 14.1%) underwent surgical treatment within 24 hours, whereas the remaining 397 patients (85.9%) underwent surgery on a standby basis (delayed group). The propensity score-matched cohorts of 63 cases were compared. RESULTS: Patients in the early group were significantly younger, had significantly more subaxial dislocations (and fractures), tetraplegia, significantly lower ASIA motor scores, and ambulatory abilities 6 months after injury. However, no significant differences in the rate of complications, ambulatory abilities, or ASIA Impairment Scale scores 6 months after injury were observed between the matched cohorts. At 6 months after injury, 61% of the patients in the early group (25% unsupported and 36% supported) and 53% of the patients in the delayed group (34% unsupported and 19% supported) were ambulatory. CONCLUSIONS: Early surgery is possible for CSI in elderly patients as the matched cohort reveals no significant difference in complication rates and neurological or ambulatory recovery between the early and delayed surgery groups.

Influence of the timing of surgery for cervical spinal cord injury without bone injury in the elderly: A retrospective multicenter study.

BACKGROUND: Although previous studies have demonstrated the advantages of early surgery for traumatic spinal cord injury (SCI), the appropriate surgical timing for cervical SCIs (CSCIs) without bone injury remains controversial. Here, we investigated the influence of relatively early surgery within 48 h of injury on the neurological recovery of elderly patients with CSCI and no bone injury. METHODS: In this retrospective multicenter study, we reviewed data from 159 consecutive patients aged ≥65 years with CSCI without bone injury who underwent surgery in participating centers between 2010 and 2020. Patients were followed up for at least 6 months following CSCI. We divided patients into relatively early (≤48 h after CSCI, n = 24) and late surgery (>48 h after CSCI, n = 135) groups, and baseline characteristics and neurological outcomes were compared between them. Multivariate analysis was performed to identify factors associated with neurological recovery. RESULTS: The relatively early surgery group demonstrated a lower prevalence of cardiac disease, poorer baseline American Spinal Injury Association (ASIA) impairment scale grade, and lower baseline ASIA motor score (AMS) than those of the late surgery group (P < 0.030, P < 0.001, and P < 0.001, respectively). Although the AMS was lower in the relatively early surgery group at 6 months following injury (P = 0.001), greater improvement in this score from baseline to 6-months post injury was observed (P = 0.010). Multiple linear regression analysis revealed that relatively early surgery did not affect postoperative improvement in AMS, rather, lower baseline AMS was associated with better AMS improvement (P < 0.001). Delirium (P = 0.006), pneumonia (P = 0.030), and diabetes mellitus (P = 0.039) negatively influenced postoperative improvement. CONCLUSIONS: Although further validation by future studies is required, relatively early surgery did not show a positive influence on neurological recovery after CSCI without bone injury in the elderly.

Erratum for A Novel Technique for Pars Defect Direct Repair with a Modified Smiley Face Rod for Spondylolysis and Isthmic Spondylolisthesis.

[This corrects the article DOI: 10.22603/ssrr.2023-0021.].

A Novel Technique for Pars Defect Direct Repair with a Modified Smiley Face Rod for Spondylolysis and Isthmic Spondylolisthesis.

Introduction: Lumbar spondylolysis is a common fatigue fracture of the pars interarticularis of the lamina of the lumbar spine in adolescent athletes presenting with pars clefts. Some pseudarthrotic lumbar spondylolysis causes low back pain or radiculopathy. This study presents a case of pseudarthrotic lumbar spondylolysis that was successfully treated using a modified smiley face rod technique. Technical Note: We developed a modified smiley face rod technique, which places pedicle screws in the lateral edge of the pedicle to preserve the erector spinae muscles and inserts a U-shaped rod between the spinous processes to preserve the supraspinous ligament. When a U-shaped rod penetrates the interspinous ligament subcutaneously, the resection of the supraspinous ligaments can be avoided. When the screw head is positioned more anterolaterally, a compression force is applied perpendicular to the surface of the pars cleft by rod clamping. This intrasegmental fusion technique preserves the mobile segment and simultaneously repairs the pars cleft. It is less invasive and more appropriate than interbody fusion for young athletes to avoid the possibility of future adjacent segment disorders. Conclusions: This is a minimally invasive procedure that can easily achieve bone fusion and should be introduced for patients who are suffering from the symptoms of pseudarthrotic lumbar spondylolysis.

Epidemiological differences between the sexes in adolescent patients with lumbar spondylolysis: a single-institution experience in Japan.

BACKGROUND: Lumbar spondylolysis, a common identifiable cause of low back pain in young athletes, reportedly has a higher incidence rate in males. However, the reason for its higher incidence in males is not clear. This study aimed to investigate the epidemiological differences between the sexes in adolescent patients with lumbar spondylolysis. METHODS: A retrospective study was conducted in 197 males and 64 females diagnosed with lumbar spondylolysis. These patients visited our institution from April 2014 to March 2020 with their main complaint being low back pain, and they were followed-up until the end of their treatment. We investigated associations between lumbar spondylosis, their background factors, and characteristics of the lesions and analyzed their treatment results. RESULTS: Males had a higher prevalence of spina bifida occulta (SBO) (p = 0.0026), more lesions with bone marrow edema (p = 0.0097), and more lesions in the L5 vertebrae (p = 0.021) than females. The popular sports disciplines were baseball, soccer, and track and field in males, and volleyball, basketball, softball in females. The dropout rate, age at diagnosis, bone union rate, and treatment period did not differ between the sexes. CONCLUSION: Lumbar spondylolysis was more common in males than in females. SBO, bone marrow edema, and L5 lesions were more frequent in males, and sports discipline varied between the sexes.

Prognosis of Cervical Diffuse Idiopathic Skeletal Hyperostosis-Related Spine Injuries in Elderly Patients: Analyses of Both Fracture and Spinal Cord Injury Without Fracture.

STUDY DESIGN: Retrospective multicenter study. OBJECTIVE: The purpose of this study was to compare the prognosis of elderly patients with injuries related to cervical diffuse idiopathic skeletal hyperostosis (cDISH) to matched control for each group, with and without fractures. METHODS: The current multicenter study was a retrospective analysis of 140 patients aged 65 years or older with cDISH-related cervical spine injuries; 106 fractures and 34 spinal cord injuries without fracture were identified. Propensity score-matched cohorts from 1363 patients without cDISH were generated and compared. Logistic regression analysis was performed to determine the risk of early mortality for patients with cDISH-related injury. RESULTS: Patients with cDISH-related injuries with fracture did not differ significantly in the incidence of each complication and ambulation or severity of paralysis compared to matched controls. In patients with cDISH-related injury without fracture, those who were nonambulatory at discharge comprised 55% vs 34% of controls, indicating significantly poorer ambulation in those with cDISH-related injuries (P = .023). There was no significant difference in the incidence of complications and ambulation or paralysis severity at 6 months as compared with controls. Fourteen patients died within 3 months. Logistic regression analysis identified complete paralysis (odds ratio [OR] 36.99) and age (OR 1.24) as significant risk factors for mortality. CONCLUSIONS: The current study showed no significant differences in the incidence of complications, ambulation outcomes between patients with cDISH-related injury with fracture and matched controls, and that the ambulation at discharge for patients with cDISH-related injury without fractures were significantly inferior to those of matched controls.

Sacroiliac Joint Ankylosis Decreases Intervertebral Fusion Rate in L5/S1 Single Intervertebral Transforaminal Lumbar Interbody Fusion.

Background Transforaminal lumbar interbody fusion (TLIF) is a common surgical procedure for lumbar spondylolisthesis and intervertebral foraminal stenosis. Sacroiliac joint ankylosis is also known to occur in patients without axial spondyloarthritis. When sacroiliac joint bony ankylosis occurs and sacroiliac joint mobility is lost, stresses from the lower extremities to the lumbar spine are no longer buffered and are expected to be concentrated between the fifth lumbar (L5) and the first sacral (S1) vertebrae. We hypothesized that sacroiliac joint bony ankylosis could adversely affect L5/S1 intervertebral fusion and investigated the postoperative intervertebral fusion rate in single intervertebral TLIF on L5/S1 among patients with bony ankylosis of the sacroiliac joint. Methods Seventy-two patients who had undergone TLIF in the L5/S1 single intervertebral segment since 2014 and had a follow-up of at least one year after surgery were included in the study. Seventy-two patients were divided into the following two groups for comparison: group A consisted of 17 patients with bony ankylosis of the sacroiliac joint on either side on preoperative CT, and group N consisted of 55 patients without ankylosis. We investigated the intervertebral segment fusion rate one year postoperatively. Fisher's exact tests were used for statistical analysis, with a significance level of P < 0.05. Results Twelve patients (71%) in group A and 50 patients (91%) in group N had a fusion of the L5/S1 intervertebral segment one year after TLIF surgery, with a significantly lower rate in group A (P = 0.049). Conclusions We conclude that the presence of preoperative sacroiliac joint bony ankylosis is a risk factor for postoperative intervertebral fusion failure after single-segment TLIF at L5/S1.

Prognostic impact of respiratory dysfunction in elderly patients with cervical spinal cord injury and/or fractures: a multicenter survey.

PURPOSE: To investigate the impact of early post-injury respiratory dysfunction for neurological and ambulatory ability recovery in patients with cervical spinal cord injury (SCI) and/or fractures. METHODS: We included 1,353 elderly patients with SCI and/or fractures from 78 institutions in Japan. Patients who required early tracheostomy and ventilator management and those who developed respiratory complications were included in the respiratory dysfunction group, which was further classified into mild and severe respiratory groups based on respiratory weaning management. Patient characteristics, laboratory data, neurological impairment scale scores, complications at injury, and surgical treatment were evaluated. We performed a propensity score-matched analysis to compare neurological outcomes and mobility between groups. RESULTS: Overall, 104 patients (7.8%) had impaired respiratory function. In propensity score-matched analysis, the respiratory dysfunction group had a lower home discharge and ambulation rates (p = 0.018, p = 0.001, respectively), and higher rate of severe paralysis (p < 0.001) at discharge. At the final follow-up, the respiratory dysfunction group had a lower ambulation rate (p = 0.004) and higher rate of severe paralysis (p < 0.001). Twenty-six patients with severe disability required respiratory management for up to 6 months post-injury and died of respiratory complications. The mild and severe respiratory dysfunction groups had a high percentage of severe paraplegic cases with low ambulatory ability; there was no significant difference between them. The severe respiratory dysfunction group tended to have a poorer prognosis. CONCLUSION: Respiratory dysfunction in elderly patients with SCI and/or cervical fracture in the early post-injury period reflects the severity of the condition and may be a useful prognostic predictor.

Percutaneous pedicle screw fixation was effective for bone regeneration after a huge vertebral defect due to intractable pyogenic spondylitis caused by methicillin-resistant Staphylococcus aureus: a case report.

BACKGROUND: Pyogenic spondylitis by methicillin-resistant Staphylococcus aureus (MRSA) is known to be intractable. In the past, the insertion of an implant into infected vertebra was considered contraindicated in affected patients because it may exacerbate the infection, but there are increasing numbers of reports indicating the usefulness of posterior fixation to correct instability and alleviate infection. Bone grafting is often required to repair large bone defect due to infection, but free grafts can exacerbate infection and are controversial. CASE PRESENTATION: We present the case of a 58-year-old Asian man with intractable pyogenic spondylitis who had repeated septic shocks due to MRSA. Back pain from repeated pyogenic spondylitis caused by a huge bone defect in L1-2 rendered him unable to sit. Posterior fixation by percutaneous pedicle screws (PPSs) without bone transplantation improved spinal stability and regenerated bone in the huge vertebral defect. He regained his activities of daily living, had no reoccurrence of pyogenic spondylitis nor bacteremia, and was completely cured of the infection without antibiotics after removal of all screws. CONCLUSIONS: For intractable MRSA pyogenic spondylitis with instability accompanied by a huge bone defect, posterior fixation using PPSs and administration of antibacterial agents stopped the infection, allowed the bone to regenerate, and recovered the patient's activities of daily living.

Delirium Risk Score in Elderly Patients with Cervical Spinal Cord Injury and/or Cervical Fracture.

The number of elderly patients with cervical trauma is increasing. Such patients are considered to be at high risk for delirium, which is an acute neuropsychological disorder that reduces the patient's capacity to interact with their environment due to impairments in cognition. This study aimed to establish a risk score that predicts delirium in elderly patients with cervical SCI and/or cervical fracture regardless of treatment type. This retrospective cohort study included 1512 patients aged ≥65 years with cervical SCI and/or cervical fracture. The risk factors for delirium according to treatment type (surgical or conservative) were calculated using multivariate logistic regression. A delirium risk score was established as the simple arithmetic sum of points assigned to variables that were significant in the multivariate analyses. Based on the statistical results, the delirium risk score was defined using six factors: old age (≥80 years), hypoalbuminemia, cervical fracture, major organ injury, dependence on pre-injury mobility, and comorbid diabetes. The score's area under the curve for the prediction of delirium was 0.66 (p < 0.001). Although the current scoring system must be validated with an independent dataset, the system remains beneficial because it can be used after screening examinations upon hospitalization and before deciding the treatment strategy.

Acute Lumbar Pyogenic Spondylitis With Multiple Abscesses Complicated by a Septic Shock That Required Emergency Surgical Open Drainage: A Case Report.

We treated a patient with pyogenic spondylitis complicated by septic shock, who was saved by emergency surgery. The patient was a 75-year-old man with back pain, fever, and weakness in the lower limbs four days before. Upon admission to our hospital, he had tachycardia, tachypnea, fever, and fluctuating vital signs. His quick sequential organ failure assessment (SOFA) score was 2. Emergent magnetic resonance imaging showed scattered intramuscular abscesses and an epidural abscess. Gram-positive cocci were detected in a blood sample. He was diagnosed with pyogenic spondylitis complicated by sepsis. Intravenous antimicrobial therapy with cefepime, vancomycin, and clindamycin was added. However, he developed tachycardia and hypotension three hours after arrival at our hospital, so he received a blood transfusion and noradrenaline and underwent emergent surgical open drainage since percutaneous drainage was difficult to perform because of scattered abscesses. Paralysis of the proximal lower extremities was recovered after surgery. Postoperatively, the causative organism was found to be methicillin-susceptible Staphylococcus aureus and intravenous antimicrobial therapy for 81 days. Three years after surgery, the patient remains free of recurrence with improvement in the activity of daily living to the extent that he could walk. The outcome of our patient suggests that surgery may be a lifesaving measure in cases whose uncontrollable vital signs by pyogenic spondylitis are complicated by sepsis. Preoperative judgment is extremely important in difficult-to-control cases because surgical invasion can be lethal.

Effects of Dementia on Outcomes after Cervical Spine Injuries in Elderly Patients: Evaluation of 1512 Cases in a Nationwide Multicenter Study in Japan.

We aimed to retrospectively investigate the demographic characteristics and short-term outcomes of traumatic cervical spine injuries in patients with dementia. We enrolled 1512 patients aged ≥ 65 years with traumatic cervical injuries registered in a multicenter study database. Patients were divided into two groups according to the presence of dementia, and 95 patients (6.3%) had dementia. Univariate analysis revealed that the dementia group comprised patients who were older and predominantly female and had lower body mass index, higher modified 5-item frailty index (mFI-5), lower pre-injury activities of daily living (ADLs), and a larger number of comorbidities than patients without dementia. Furthermore, 61 patient pairs were selected through propensity score matching with adjustments for age, sex, pre-injury ADLs, American Spinal Injury Association Impairment Scale score at the time of injury, and the administration of surgical treatment. In the univariate analysis of the matched groups, patients with dementia had significantly lower ADLs at 6 months and a higher incidence of dysphagia up to 6 months than patients without dementia. Kaplan-Meier analysis revealed that patients with dementia had a higher mortality than those without dementia until the last follow-up. Dementia was associated with poor ADLs and higher mortality rates after traumatic cervical spine injuries in elderly patients.

Characteristics of the cervical spine and cervical cord injuries in older adults with cervical ossification of the posterior longitudinal ligament.

Although the incidence of cervical spinal cord injury (CSCI) with ossification of the posterior longitudinal ligament (OPLL) has increased in older adults, its etiology and neurological outcomes remain unknown. We identified OPLL characteristics and determined whether they influence neurological severity and improvement of CSCI in older patients. This multicenter retrospective cohort study identified 1512 patients aged ≥ 65 years diagnosed with CSCI on admission during 2010-2020. We analyzed CSCI etiology in OPLL patients. We performed propensity score-adjusted analyses to compare neurological outcomes between patients with and without OPLL. Cases were matched based on variables influencing neurological prognosis. The primary neurological outcome was rated according to the American Spine Injury Association (ASIA) impairment scale (AIS) and ASIA motor score (AMS). In 332 OPLL patients, the male-to-female ratio was approximately 4:1. Half of all patients displayed low-energy trauma-induced injury and one-third had CSCI without a bony injury. Propensity score matching created 279 pairs. There was no significant difference in the AIS grade and AMS between patients with and without OPLL during hospitalization, 6 months, and 12 months following injury. OPLL patients tended to exhibit worse neurological findings during injury; nevertheless, OPLL was not associated with poor neurological improvement in older CSCI patients.

Epidemiology of Cervical Fracture/Cervical Spinal Cord Injury and Changes in Surgical Treatment Modalities in Elderly Individuals During a 10-year Period: A Nationwide Multicenter Study in Japan.

STUDY DESIGN: Retrospective multicenter study. OBJECTIVES: To investigate changes over a 10-years period in the profile of cervical spine and spinal cord injuries among the elderly in Japan. METHODS: The current multicenter study was a retrospective analysis of inpatients aged ≥65 years, suffering cervical fracture (CF) and/or cervical spinal cord injury (CSCI). We analyzed 1413 patients' epidemiology (from 2010 to 2019). Moreover, 727 patients who underwent surgical treatment were analyzed in 2 groups: the early (2010-2014) and late period (2015-2019). RESULTS: Both the number of patients and number of surgical patients showed a significant increasing trend (P < .001), while the mean age, the distribution of injury levels and paralysis severity, and the proportion of surgical indications remained the same. The number of surgical patients doubled from 228 to 499 from the early to late periods. Posterior surgery was the most common approach (90.4%), instrumentation surgery with screws increased significantly, and the range of fusion was significantly longer in the late period (2.1 vs 2.7 levels, P = .001). Significantly worsening neurological symptoms were recorded in the late period (1.3% vs 5.8%, P = .006), with C5 palsy being the major one. Otherwise, perioperative, major, and other complications, including mortality, did not differ significantly in incidence. CONCLUSIONS: Both the number of elderly CF and/or CSCI patients and number of patients undergoing surgery increased dramatically over the decade without any change in profile. Instrumentation surgeries with screws increased, without an increase in systemic complications.

Risk Factors for Early Mortality in Older Patients with Traumatic Cervical Spine Injuries-A Multicenter Retrospective Study of 1512 Cases.

For older patients with decreased reserve function, traumatic cervical spine injuries frequently lead to early mortality. However, the prognostic factors for early mortality remain unclear. This study included patients aged ≥65 years and hospitalized for treatment of traumatic cervical spine injuries in 78 hospitals between 2010 and 2020. Early mortality was defined as death within 90 days after injury. We evaluated the relationship between early mortality and the following factors: age, sex, body mass index, history of drinking and smoking, injury mechanisms, presence of a cervical spine fracture and dislocation, cervical ossification of the posterior longitudinal ligament, diffuse idiopathic skeletal hyperostosis, American Spinal Injury Association Impairment Scale, concomitant injury, pre-existing comorbidities, steroid administration, and treatment plan. Overall, 1512 patients (mean age, 75.8 ± 6.9 years) were included in the study. The early mortality rate was 4.0%. Multivariate analysis identified older age (OR = 1.1, p < 0.001), male sex (OR = 3.7, p = 0.009), cervical spine fracture (OR = 4.2, p < 0.001), complete motor paralysis (OR = 8.4, p < 0.001), and chronic kidney disease (OR = 5.3, p < 0.001) as risk factors for early mortality. Older age, male sex, cervical spine fracture, complete motor paralysis, and chronic kidney disease are prognostic factors for early mortality in older patients with traumatic cervical spine injuries.

The relationship between spinal alignment and activity of paravertebral muscle during gait in patients with adult spinal deformity: a retrospective study.

BACKGROUND: Spinal alignment in patients with adult spinal deformity (ASD) changes between rest and during gait. However, it remains unclear at which point the compensated walking posture breaks down and how muscles respond. This study used time-synchronized electromyography (EMG) to investigate the relationship between dynamic spinal alignment and muscle activity during maximum walking duration to reveal compensation mechanisms. METHODS: This study collected preoperative three-dimensional gait analysis data from patients who were candidates for corrective surgery for ASD from April 2015 to May 2019. We preoperatively obtained dynamic spinal alignment parameters from initiation to cessation of gait using a motion capture system with time-synchronized surface integrated EMG (iEMG). We compared chronological changes in dynamic spinal alignment parameters and iEMG values 1) immediately after gait initiation (first trial), 2) half of the distance walked (half trial), and 3) immediately before cessation (last trial). RESULTS: This study included 26 patients (22 women, four men) with ASD. Spinal sagittal vertical axis distance during gait (SpSVA) increased over time (first vs. half vs. last, 172.4 ± 74.8 mm vs. 179.9 ± 76.8 mm vs. 201.6 ± 83.1 mm; P < 0.001). Cervical paravertebral muscle (PVM) and gluteus maximus activity significantly increased (P < 0.01), but thoracic and lumbar PVM activity did not change. Dynamic spinal alignment showed significant correlation with all muscle activity (cervical PVM, r = 0.41-0.54; thoracic PVM, r = 0.49-0.66; gluteus maximus, r = 0.54-0.69; quadriceps, r = 0.46-0.55) except lumbar PVM activity. CONCLUSION: Spinal balance exacerbation occurred continuously in patients with ASD over maximum walking distance and not at specific points. To maintain horizontal gaze, cervical PVM and gluteus maximus were activated to compensate for a dynamic spinal alignment change. All muscle activities, except lumbar PVM, increased to compensate for the spinal malalignment over time.