Mixed Reality-Based Navigation for Pedicle Screw Placement: A Preliminary Study Using a 3D-Printed Spine Model.

Background and objectives Mixed reality (MR) is one of the image processing technologies that allows the user to manipulate three-dimensional (3D) virtual images (hologram). The aim of this study was to evaluate the accuracy of MR-based pedicle screw (PS) placement using 3D spine models. Materials and methods Using the preoperative CT data of a patient with adolescent idiopathic scoliosis (AIS) who had undergone posterior spinal fusion in our hospital, a 3D-printed spine model was created. On the other hand, a 3D hologram of the same patient was automatically created using the preoperative CT data uploaded to the Holoeyes MD service website (Holoeyes Inc., Tokyo, Japan). Using a Magic Leap One® headset (Magic Leap Inc., Plantation, FL), the 3D hologram with lines of predetermined PS trajectories was superimposed onto the 3D-printed spine model and PS were inserted bilaterally along with the trajectory lines from T5 to L3. As a control, we used a readymade 3D spine model of AIS and inserted PS bilaterally with a freehand technique from T4 to L3. The rate of pedicle violation was compared between the MR-based and freehand techniques. Results A total of 22 and 24 PS were placed into the 3D-printed spine model of our patient and the readymade 3D spine model, respectively. The rate of pedicle violation was 4.5% (1/22 screws) in the MR-based technique and 29.2% (7/24 screws) in the freehand technique (P = 0.049). Conclusions We demonstrated a significantly lower rate of PS misplacement in the MR-based technique than in the freehand technique. Therefore, an MR-assisted system is a promising tool for PS placement in terms of feasibility, safety, and accuracy, warranting further studies including cadaveric and clinical studies.

Neck and shoulder pain in thoracic adolescent idiopathic scoliosis 10 years after posterior spinal fusion.

PURPOSE: We aimed to determine the clinical significance of neck and shoulder pain (NSP) 10 years after posterior spinal fusion (PSF) for thoracic adolescent idiopathic scoliosis (AIS) and the relationship between radiographic parameters and NSP. METHODS: Of 72 patients who underwent PSF for thoracic AIS (Lenke 1 or 2) between 2000 and 2013, we included 52 (46 females; Lenke type 1 in 34 patients and type 2 in 18; mean age, 25.6 years) who underwent NSP evaluation using visual analog scale (VAS, 10 cm) 10 years postoperatively (follow-up rate, 72.2%). Correlation analyses were performed using Spearman's rank correlation coefficient (r). RESULTS: The VAS for NSP was 2.6 cm in median and 3.4 cm in mean at 10 years. The VAS had significant negative correlations with several SRS-22 domain scores (rs = - 0.348 for pain, - 0.347 for function, - 0.308 for mental health, and - 0.372 for total) (p < 0.05). In addition, the VAS score was significantly correlated with cervical lordosis (CL) (rs = 0.296), lumbar lordosis (rs = - 0.299), and sacral slope (rs = 0.362) (p < 0.05). Furthermore, at the 10-year follow-up, CL was significantly negatively correlated with T1 slope (rs = - 0.763) and thoracic kyphosis (TK) (- 0.554 for T1-12 and - 0.344 for T5-12) (p < 0.02). CONCLUSION: NSP was associated with deterioration in SRS-22 scores, indicating that NSP is a clinically significant long-term issue in PSF for thoracic AIS. Restoring or maintaining the TK and T1 slopes, which are controllable factors during PSF, may improve cervical lordosis and alleviate NSP at 10-year follow-up.

Delayed paraparesis after posterior spinal fusion for congenital scoliosis: a case report.

INTRODUCTION: Although multimodal intraoperative neuromonitoring (IONM), which has high sensitivity and specificity, is typically performed during spinal deformity surgery, neurological status may deteriorate with delay after surgical maneuvers. Here, we report a rare case of delayed postoperative neurological deficit (DPND) that was not detected by IONM during posterior spinal fusion (PSF) for congenital scoliosis. CASE PRESENTATION: A 14-year-old male presented with congenital scoliosis associated with T3 and T10 hemivertebrae. Preoperative Cobb angle of proximal thoracic (PT) and main thoracic (MT) curves were 50° and 41°, respectively. PSF (T1-L1) without hemivertebrectomy was performed, and the curves were corrected to 31° and 21° in the PT and MT curves, respectively, without any abnormal findings in IONM, blood pressure, or hemoglobin level. However, postoperative neurological examination revealed complete loss of motor function. A revision surgery, release of the curve correction by removing the rods, was immediately performed and muscle strength completely recovered on the first postoperative day. Five days postoperatively, PSF was achieved with less curve correction (36° in the PT curve and 26° in the MT curve), without postoperative neurological deficits. DISCUSSION: Possible mechanisms of DPND in our patient are spinal cord ischemia due to spinal cord traction caused by scoliosis correction and spinal cord kinking by the pedicle at the concave side. Understanding the possible mechanisms of intra- and postoperative neural injury is essential for appropriate intervention in each situation. Additionally, IONM should be continued to at least skin closure to detect DPND observed in our patient.

Anatomical Pelvic Parameters Using the Anterior Pelvic Plane: Normative Values and Estimation of the Standing Sagittal Alignment in Healthy Volunteers.

Introduction: In this study, we aim to estimate the natural standing sagittal alignment in patients with adult spinal deformity (ASD), firstly by investigating the normative values of anatomical pelvic parameters based on the anterior pelvic plane (APP) in a healthy population, and to clarify the relationships between the anatomical and positional pelvic parameters in standing position. Methods: The images of biplanar slot-scanning full-body stereoradiography in 140 healthy Japanese volunteers (mean age, 39.5 years; 59.3% female) were examined. In addition to three-dimensional measurements including pelvic incidence (PI), sacral slope (SS), and pelvic tilt (PT), the APP angle (APPA; anterior tilting=positive) was measured as the angle between the APP and the vertical line using the two-dimensional lateral image. Anatomical SS and PT (aSS and aPT) were calculated as the angles of SS and PT in reference to APP. Results: The mean (range) values of APPA, aSS, and aPT were determined to be 0.7° (-16.8°/15.5°), 36.8° (18.3°/64.9°), and 13.2° (-0.6°/28.7°), respectively. Moreover, SS was found to be significantly correlated with PI and aSS, while PT was significantly correlated with PI, aSS, aPT, and body weight. Also, PT was significantly larger in females than in males. Multiple linear regression analysis deduced the following equations: SS=0.404×aSS+0.203×PI+12.463, PT=-0.391×aSS+0.774×PI+1.950×sex (male=0, female=1)-12.971, wherein aSS had the greatest effect for predicting SS among the included factors and PI had the greatest effect for predicting PT. In addition, no significant differences were noted between PT/PI and aPT/PI. Conclusions: As per the results of this study, significant correlations were noted among parameters and predicting models for positional parameters (SS and PT) using anatomical parameters (aSS and aPT) in a healthy population. This novel measurement concept based on the APP has been considered to be useful in estimating natural SS and PT in standing position using the anatomical pelvic parameters in patients with ASD.

Gait Analysis by the Severity of Gait Disturbance in Patients with Compressive Cervical Myelopathy.

Introduction: Gait disturbance due to compressive cervical myelopathy has been previously described. However, data on how gait disturbance varies with the degree of lower extremity motor impairment are limited. Therefore, we investigated the characteristics of gait analysis based on severity and determined how gait disturbance progresses in compressive cervical myelopathy. Methods: We enrolled 44 patients (32 men and 12 women; mean age, 65.0 years) out of 108 consecutive patients with compressive cervical myelopathy who underwent spinal cord decompression surgery in our hospital. The exclusion criteria were inability to gait and complications affecting gait. Twenty-two patients with Japanese Orthopaedic Association scores 1 or 2 for lower extremity motor functions were assigned to the severe group, and 22 patients who scored 3 or 4 were assigned to the moderate group. Gait analysis was performed preoperatively using a long thin-type sensor sheet, and 25 healthy volunteers were assigned to the control group. Results: Stride length, swing phase, and gait speed decreased whereas step angle, stance phase, and double support duration increased as myelopathy progressed. Step width was significantly larger in the severe group than in the moderate and control groups. The cutoff values based on severe myelopathy with the inability to ascend or descend stairs without support were 60% for the stride length percentage of body height and 100 cm/s for gait speed. Conclusions: Decreases in stride length, swing phase, and gait speed and increases in step angle, stance phase, and double support duration are compensatory changes as cervical myelopathy progresses. Step width is a compensatory change that is not significantly altered in moderate myelopathy but increases when gait becomes affected, such that the patient cannot ascend or descend stairs without support.

Characteristics of back pain in patients with adolescent idiopathic scoliosis: Considerations in candidates for corrective surgery.

BACKGROUND: Previous studies have demonstrated that the point prevalence of back pain ranges from 12 % to 33 % and that the lifetime prevalence of back pain ranges from 28 % to 51 % in adolescents. However, few studies on back pain in patients with Adolescent idiopathic scoliosis (AIS) have been conducted, and these studies had significant limitations, including a lack of comparative controls and detailed information about scoliotic deformity or pain location. This study aimed to determine whether adolescents with AIS experience back pain in specific regions. METHODS: This retrospective case-control study included 189 female adolescents with AIS who underwent corrective fusion from 2008 to 2020. Questionnaires on back pain and health-related quality of life (HRQOL) using the Scoliosis Research Society Outcomes Instrument-22 (SRS-22) were conducted preoperatively. The control group included 2909 general female adolescents. RESULTS: The mean Cobb angles in the main thoracic and thoracolumbar/lumbar curves were 51.4 ± 15.3° and 40.4 ± 12.9°. Back pain characteristics included higher point prevalence (25.9 %) and lifetime prevalence (64.6 %) compared to healthy controls. Adolescents with back pain showed lower scores in the pain and mental health domains of the SRS-22. Adolescents with major thoracic AIS showed more back pain in the upper and middle right back compared to adolescents with major thoracolumbar/lumbar AIS. CONCLUSION: The point and lifetime prevalence of back pain were definitely higher in patients with AIS, which affected their HRQOL. There was a relationship between pain around the right scapula and the right major thoracic curve with a rib hump deformity.

Usefulness and limitations of intraoperative pathological diagnosis using frozen sections for spinal cord tumors.

BACKGROUND: Intraoperative pathological diagnosis has a major influence on the intra- and postoperative management of spinal cord tumors. Thus, the aim of this study was to assess the reliability of intraoperative pathological diagnosis for spinal cord lesions by comparing it with the final pathological diagnosis and to determine its usefulness and limitations. METHOD: Three-hundred and three consecutive patients (mean age, 53.9 years) with neoplastic spinal cord lesions who underwent initial surgery between 2000 and 2021 were included. The anatomical locations of the spinal cord tumors and the implementation rate of intraoperative pathological diagnosis in each tumor type were evaluated. As the primary outcome, we determined the concordance rates between the intraoperative pathological diagnosis and the final diagnosis. When the intraoperative pathological diagnosis and final diagnosis were the same, the diagnosis was defined as a "match." Otherwise, the diagnosis was defined as a "mismatch." RESULTS: The overall implementation rate of intraoperative pathological diagnosis was 53%, with implementation rates of 71%, 45%, 47%, and 50% for intramedullary, intradural extramedullary, extradural, and dumbbell tumors, respectively. The overall concordance rate was 87.6%, with concordance rates of 80%, 95%, 75%, and 90% for intramedullary, intradural extramedullary, extradural, and dumbbell tumors, respectively (p < 0.05). The diagnoses of ependymomas, low-grade astrocytomas, and high-grade astrocytomas was occasionally difficult among intramedullary tumors. Among intradural extramedullary tumors, differentiation between grade 1 meningioma and high-grade meningioma was difficult using intraoperative pathological diagnosis. CONCLUSIONS: Surgeons must recognize the lower accuracy of intraoperative pathological diagnosis for intramedullary and extradural lesions and make a final decision by considering the intraoperative gross findings, preoperative clinical course, and imaging.

Impact of spinal sagittal malalignment on locomotive syndrome and physical function in community-dwelling middle aged and older women.

BACKGROUND: Adult spinal deformity has a substantially debilitating effect on older people's physical and mental health. However, the impact of sagittal malalignment on locomotive syndrome (LS), sarcopenia, and physical function in community-dwelling older women has not yet been clarified. This study aimed to investigate the association between these factors in community-dwelling middle aged and older women. METHODS: A total of 361 women were recruited from participants performing aquatic exercises in a rural area of Japan. The body mass index, skeletal muscle mass index, trunk muscle mass, spinal inclination angle (SIA), grip strength, timed up-and-go test (TUG), maximum stride of the participants, and one-leg standing time were measured. Low back pain (LBP)- and health-related quality of life (HRQOL) were evaluated using the Oswestry Disability Index (ODI) and the Short-Form 8 questionnaire. Associations between the global sagittal alignment using SIA and investigating parameters were analyzed. RESULTS: The prevalence of sarcopenia was 3.6%. The prevalence of LS (stages 1, 2, and 3) was 43.8% (158 of 361), and the number of participants in each LS stage was 203 (stage 0), 95 (stage 1), 28 (stage 2), and 35 (stage 3). The SIA was significantly correlated with the 25-question geriatric locomotive function scale (r' = 0.292, p < 0.001), ODI (r' = 0.267, p < 0.001), and TUG (r' = 0.453, p < 0.001) after adjusting for age. In the receiver-operating characteristic curve analysis, the cutoff values of SIA for LS ≥ stage 2 and ODI ≥ 20% were 5°. CONCLUSIONS: LBP-related QOL and physical performance were significantly associated with global sagittal alignment. Global sagittal alignment was correlated with the three-stage category of LS. The spinal inclination of 5° was a cutoff value to predict exacerbation of mobility function and HRQOL status.

Marriage and childbirth of patients who were surgically and non-surgically treated for adolescent idiopathic scoliosis: a survey at the age of 30 years or older.

PURPOSE: We aimed to investigate the marital status and childbirth in adolescent idiopathic scoliosis (AIS) patients. METHODS: This study included women who were treated surgically or non-surgically for AIS with a scoliosis magnitude ≥ 30° before surgery or at skeletal maturity and were followed up until age 30 years or older. Patients were divided into surgically treated (S-AIS, n = 55) and non-surgically treated AIS groups (N-AIS, n = 86). Data from the national fertility survey were used as control values. RESULTS: There were no significant differences in age at the final follow-up between the S- (40.7 years) and N-AIS (42.1 years) groups. The unmarried rate among all women and the nulliparous rate among married women in the S-AIS group (29.1% and 18.4%, respectively) were similar to those in the N-AIS group (26.7% and 16.1%, respectively). The mean number of children per married woman also did not differ between the S- and N-AIS groups (1.5 vs 1.4). Compared to the control group, after adjusting for age, the common odds ratio in the AIS group was 1.56 (p = 0.031) for unmarried status and 1.88 (p = 0.026) for nulliparity among married women. Moreover, the mean number of children per married woman was significantly lower in the AIS group than in the control group (1.3 vs 1.7, p < 0.001). CONCLUSION: Surgically and non-surgically treated women with AIS had a similar status with regard to marriage and childbirth, while women with AIS were more likely to be unmarried and nulliparous and to have fewer children compared to the nationwide population.

Evaluating flexibility and predicting curve correction using fulcrum-bending radiographs in Lenke type 2 adolescent idiopathic scoliosis.

BACKGROUND: Fulcrum-bending (FB) correction is considered to provide the best estimation of main thoracic (MT) curve flexibility and postoperative correction in surgical treatment for adolescent idiopathic scoliosis (AIS). However, few studies evaluated the usefulness of FB radiographs for proximal thoracic (PT) curve. We aimed to perform flexibility assessments using both active side-bending (SB) and FB radiographs and evaluate surgical outcomes after posterior spinal fusion (PSF) for Lenke type 2 AIS. METHODS: This study included 38 consecutive patients with Lenke type 2 AIS who underwent PSF using a pedicle screw construct with a minimum 2-year follow-up. Radiographic parameters, including correction rate, SB and FB flexibility, and FB correction index (FBCI: [correction rate/FB flexibility] × 100), were evaluated preoperatively, immediately after surgery, and at the 2-year follow-up. The clinical outcomes were preoperatively evaluated using the Scoliosis Research Outcomes Instrument-22 and at the follow-up. RESULTS: All scoliosis curves significantly improved and shoulder balance shifted toward left shoulder elevation (all comparisons, p < 0.0001). There were significant differences between the SB and FB corrections in the PT and MT curves (p < 0.0001). The magnitudes of the discrepancies between the SB and FB corrections in the PT and MT curves were 11.2° ± 5.2° and 11.6° ± 7.2°, respectively. FB correction did not differ from postoperative Cobb angles correction immediately after surgery or at the 2-year follow-up; the mean FBCIs in the PT and MT curves were 98.8% and 105.5%, respectively. The self-image domain SRS-22 scores had significantly increased at the 2-year follow-up (p < 0.0001). CONCLUSIONS: There were significant differences between the SB and FB corrections, and FB correction tended to approximate the postoperative curve correction (FBCI = 100%) for PT and MT curves in patients with Lenke type 2 AIS. FB flexibility is more reliable than SB flexibility in evaluating actual curve flexibility even for the PT curve.

Low back pain significantly influences locomotive syndrome in older people: Evaluation using the 3-stage categories.

BACKGROUND: The Japanese Orthopaedic Association (JOA) introduced the concept of locomotive syndrome (LS), which indicates a decline in mobility function by musculoskeletal disorders with new 3-staged category. Additionally, sarcopenia indicates a decline in the quantity and/or quality of skeletal muscle. However, the relationship between low back pain (LBP) and LS or sarcopenia in older people has not been sufficiently understood. This study aimed to investigate the association between them through a cross-sectional locomotorium survey. METHODS: A total of 302 participants were drawn from the aquatic exercise participants in a rural area of Japan. The body mass index, body fat percentage, skeletal muscle mass index (SMI), spinal inclination angle (SIA), grip strength, timed up-and-go test (TUG), and maximum stride of the participants were measured. LBP and LBP-related quality of life (QOL) were evaluated using the Oswestry Disability Index (ODI), visual analogue scale (VAS) of LBP, and the Short-Form 8 (SF-8). Associations between the investigating parameters and sarcopenia or LS were analyzed. RESULTS: There were no significant differences in the findings except grip strength between the non-sarcopenia and sarcopenia groups. However, the LS group showed significantly larger SIA, higher ODI, higher VAS of LBP, lower physical component score (PCS) of the SF-8, longer time in TUG, and lower value in maximum stride than the non-LS group. In addition, the ODI and PCS of the SF-8 significantly deteriorated as the LS stage progressed, and the GLFS-25 score was significantly correlated with ODI (r = 0.706, p < 0.001) and PCS (r = -0.643, p < 0.001) scores. CONCLUSIONS: LBP, LBP-related QOL, and physical performance were found to be significantly associated with LS, not sarcopenia, with LBP-related QOL and physical function being closely correlated with 3-stage categories of LS. Thus, these results suggested that LBP is a key factor for LS prevalence.

Axial Neck-Shoulder Pain After Posterior Correction and Fusion for Adolescent Idiopathic Scoliosis With Structural Thoracic Curve: Does Cranial Fusion Level Affect Neck Symptoms?

STUDY DESIGN: A retrospective cohort study using prospectively collected data. OBJECTIVES: To investigate the incidence and impact of fusion to the upper thoracic spine on neck-shoulder symptoms after posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS). SUMMARY OF BACKGROUND DATA: Axial neck-shoulder pain is established as a sequela of posterior cervical spine surgery and is mainly caused by the dissection of extensor muscles in the cervical and upper thoracic spine. MATERIALS AND METHODS: Sixty-three female patients with AIS who underwent PSF using segmental pedicle screw constructs for structural main thoracic curve with a minimum 2-year follow-up were included. Axial neck-shoulder pain was assessed using the visual analog scale and cervical spine function domain score of the Japanese Orthopedic Association Cervical Myelopathy Evaluation Questionnaire. The patients were divided into 2 groups, a higher group (underwent fusion up to T3 or above, n=27) and a lower group (underwent fusion up to T4 or below, n=36), and radiologic and clinical outcomes were compared. RESULTS: The incidence of axial neck-shoulder pain (visual analog scale ≥30) preoperatively and at the 2-year follow-up was 29 and 40%, respectively. The pain and mental health domains of the Scoliosis Research Society-22 and cervical spine function domain of the Japanese Orthopedic Association Cervical Myelopathy Evaluation Questionnaire were correlated with the severity of axial neck pain. In the comparison of clinical outcomes between the 2 groups, the pain domain score of the Scoliosis Research Society-22 in the lower group was significantly better than that in the higher group at the 2-year follow-up ( P <0.05). Other parameters showed no significant differences preoperatively or at the 2-year follow-up. CONCLUSION: Female patients with AIS had a relatively high incidence of axial neck-shoulder pain after PSF, which affected their health-related quality of life. Both groups showed similar clinical outcomes, and the cranial fusion level did not affect axial neck-shoulder pain and cervical spine function. LEVEL OF EVIDENCE: Level 3.

Association of success of brace treatment and various aspects of in-brace correction in patients with adolescent idiopathic scoliosis.

BACKGROUND: Although skeletal maturity and brace wear time contribute to the success of brace treatment in adolescent idiopathic scoliosis (AIS), the extent of initial in-brace correction for ensuring successful outcomes remains unclear. We hypothesized that the degree of initial in-brace correction correlates with brace success in patients with AIS. METHOD: The study included 135 AIS patients with a major Cobb angle of 20°-40° treated with a thoracic lumbosacral orthosis for at least one year and followed up for skeletal maturity. The subjects were divided into two groups: the skeletally immature group (group I, n = 72), who met the Bracing in Adolescent Idiopathic Scoliosis Trial study protocol at the start of brace treatment, and the skeletally mature group (group M, n = 63). Treatment success was defined as not needing surgical treatment and a major Cobb angle <40° at the end of brace treatment. RESULTS: In both groups, the mean major Cobb angles before treatment, while wearing the brace, and at the end of brace treatment were 30.6°/31.7°, 22.9°/24.2°, and 38.8°/33.9° (p < 0.05), respectively, and the treatment success rate was 56.9% and 77.8%, respectively (p < 0.05). Univariate regression analysis revealed the following risk factors: Risser grade 0 in group I, major Cobb angles before treatment, initial in-brace major Cobb angle, and in-brace correction rate in both groups. Cutoff values of in-brace major Cobb angle for treatment success calculated by ROC curve in groups I and M were 24° and 29°, respectively. CONCLUSIONS: In-brace major scoliosis correction of <25° in patients with immature skeletal status and <30° in patients with mature skeletal structure should be aimed at to achieve significant brace treatment success.

Effect of adjuvant therapy with teriparatide in patients with thoracolumbar osteoporotic vertebral fractures who underwent vertebroplasty with posterior spinal fusion.

Teriparatide (TPTD) administration has a potent osteogenic action and promotes the healing of osteoporotic vertebral fractures (OVFs). We aimed to investigate the outcomes of vertebroplasty with posterior spinal fusion (VP + PSF) and determine the impact of perioperative TPTD administration. We included 73 patients (18 male and 55 female patients; mean age: 78 years) with thoracolumbar OVFs who underwent VP + PSF and were followed-up for at least 2 years. Twenty-three patients who received TPTD perioperatively for > 3 months were included in the TPTD group, and the remaining 50 patients were included in the non-TPTD group. Radiographic findings regarding sagittal alignment and clinical outcomes in both groups were compared. The mean duration of TPTD administration was 17.5 ± 5.0 months (range 4-24 months). The mean loss of correction of local kyphosis angle in the TPTD group (4.0°) was lesser than that in the non-TPTD group (7.5°; p < 0.05); however, no significant differences were observed between the groups regarding global sagittal alignment, the occurrence of subsequent vertebral fractures, pedicle screw loosening and treatment-efficacy rates of clinical outcomes. Local kyphosis correction in patients who underwent VP + PSF for OVFs could be maintained through perioperative TPTD administration; however, TPTD administration had little effect on clinical outcomes.

Impact of the flexibility of the spinal deformity on low back pain and disc degeneration in adult patients nonoperatively treated for adolescent idiopathic scoliosis with thoracolumbar or lumbar curves.

PURPOSE: To evaluate the impact of the flexibility of thoracolumbar or lumbar (TL/L) curves on low back pain (LBP) and disc degeneration in adult patients nonoperatively treated for adolescent idiopathic scoliosis (AIS). METHODS: Forty-seven adult patients (46 women; mean age, 40.5 years) nonoperatively treated for AIS with TL/L curves were included. The patients completed radiological examinations, magnetic resonance imaging, and a questionnaire survey for LBP evaluation. The flexibility of the spinal deformity was evaluated using supine side-bending radiographs. Radiographic measurements were correlated with scores for LBP and disc degeneration. RESULTS: The average magnitude and flexibility of the TL/L curve were 49.0° and 56%, respectively. The magnitudes of the TL/L curve and disc wedging were significantly correlated with LBP (|r|= 0.3-0.4). The flexibility of the TL/L curve and disc wedging, and the lumbar lateral range of motion (ROM) were significantly correlated with LBP and disc degeneration (|r|= 0.3-0.5). After controlling for the magnitudes of the TL/L curve and disc wedging, the flexibility of L4/5 disc wedging and the lumbar lateral ROM remained significantly correlated with the Scoliosis Research Society-22 pain score (partial correlation coefficient [r'] = 0.5 and 0.3), Oswestry Disability Index (- 0.3 and - 0.3), and disc degeneration (- 0.4 and 0.3). CONCLUSION: In AIS patients with TL/L curves, the flexibility of L4/5 disc wedging and the lumbar lateral ROM were significantly correlated with LBP and disc degeneration, independent of the magnitudes of the coronal deformities. Our findings indicate that maintaining or improving lumbar flexibility may be beneficial for preventing or treating LBP.

Five-year longitudinal study of frailty prevalence and course assessed using the Kihon Checklist among community-dwelling older adults in Japan.

The aim of this study was to analyze the 5-year natural course of frailty status assessed with the Kihon Checklist (KCL) and the risk factors of transition towards frailty in community-dwelling older adults. We used the data from the postal KCL survey conducted by the municipal government between 2011 and 2016. The sample of the current study consisted of 551 older adults (265 men and 286 women) aged 65-70 years in 2011. The median KCL score increased from 2 (interquartile range 1-3) in 2011 to 3 (1-5) in 2016 (p < 0.001). Hence, the prevalence of frailty increased from 8.0 to 12.3% (p < 0.001). Regarding the 5-year transitions in frailty status, 68.3% of participants remained unchanged, while 21.4% transitioned towards a worse frailty status, and 10.3% towards an improved status. Of the 507 respondents who were robust or prefrail at the baseline, 44 experienced a transition towards frailty, indicating that the 5-year incidence of frailty was 8.7%. These 44 individuals had higher body mass indexes (BMI) and lower physical activity scores on the KCL than others (p < 0.05), the latter of which was an independent predictor of transition toward frailty in the multivariate analysis. This study was the first to evaluate the 5-year natural course of frailty status assessed using the KCL in community-dwelling elderly adults, in which the prevalence of frailty increased by 4.3%. To prevent transition towards frailty, maintaining optimal physical activity is recommended.

Repeated cerebellar infarction in the affected nondominant vertebral artery distribution with reversible vertebral artery occlusion elicited by head tilt: illustrative case.

BACKGROUND: Bow hunter's syndrome or stroke (BHS) is characterized by rotational vertebrobasilar insufficiency elicited by rotation of the neck. It is caused by dynamic and reversible occlusion of the vertebral artery (VA). Reversible symptoms of rotational vertebrobasilar insufficiency are described as bow hunter's syndrome, although brain infarction is rarely reported as bow hunter's stroke. OBSERVATIONS: A 70-year-old man experienced repeated cerebellar infarctions three times in the posterior inferior cerebellar artery (PICA) distribution of the nondominant right VA connecting the basilar artery. The onset of symptoms indicating cerebellar infarcts and the patient's head position changes were unrelated. Dynamic digital angiography (DA) revealed that the nondominant right VA was occluded by an osteophyte from the C4 vertebral body, and the right PICA branches were shown to be passing through the distal right VA from the left VA. These findings were observed when the patient's head was tilted to the right. An arterio-arterial embolic mechanism was suggested as the cause of repeated cerebellar infarctions. LESSONS: Transient nondominant VA occlusion has been rarely reported as a cause of BHS when the head is tilted. To confirm the diagnosis of BHS, additional head tilt is recommended when performing dynamic DA in patients with a cervical osteophyte.

Impact of L4/5 Posterior Interbody Fusion With or Without Decompression on Spinopelvic Alignment and Health-related Quality-of-Life Outcomes.

STUDY DESIGN: This was a retrospective case control study. OBJECTIVE: The objective was to determine the impact of single-level interbody fusion at L4/5 with or without concomitant decompression on various spinopelvic parameters and health-related quality-of-life (HRQOL) outcomes. SUMMARY OF BACKGROUND DATA: Recently, focus has swayed from a regional concern to a global sagittal alignment, more comprehensive approach in multilevel, corrective fusion for adult spinal deformity. However, only a few comprehensive studies have investigated the relationships between the various related spinopelvic parameters and HRQOL outcomes using single-level interbody fusion. MATERIALS AND METHODS: In total, 119 patients with lumbar degenerative disorders (mean age, 68 y; 38 males and 81 females) who underwent L4/5 single-level posterior interbody fusion with a minimum 2-year follow-up were included. Participants were divided into 2 groups according to preoperative sagittal modifiers of the SRS-Schwab adult spinal deformity classification. The correlation between spinopelvic parameters and HRQOL outcomes was investigated. Negative or positive values indicated lordosis. HRQOL outcomes were assessed using visual analog scale scores, Japanese Orthopedic Association Back Pain Evaluation Questionnaires (JOABPEQ), and short form-36 (SF-36). RESULTS: L4/5 local lordosis increased from 6.4±4.4 degrees preoperatively to 11.3±4.5 degrees at 2 years postoperatively (P<0.0001). Further analysis of the results also showed a correlation between change in L4/5 local lordosis and change in lumbar lordosis (LL) (rs=0.229, P=0.0143). The high pelvic incidence-LL (≥20 degrees, n=28) and high sagittal vertical axis groups (≥5 cm, n=29) had lower scores in walking ability, social life domains of JOABPEQ, and physical component summary scores of SF-36 preoperatively, and 2 years postoperatively. Fusion status did not affect the HRQOL outcomes, except that concomitant decompression at the adjacent disk level yielded lower SF-36 physical component summary scores 2 years postoperatively. CONCLUSIONS: Improvement in L4/5 local lordosis possibly triggers a simultaneous sequence of change in total LL after posterior single-level fusion. HRQOL outcomes were negatively affected by both preoperative and postoperative pelvic incidence-LL mismatch and global sagittal malalignment. LEVEL OF EVIDENCE: Level III.

Health-Related Quality of Life in Nonoperated Patients With Adolescent Idiopathic Scoliosis in the Middle Years: A Mean 25-Year Follow-up Study.

STUDY DESIGN: A retrospective long-term follow-up study. OBJECTIVE: To investigate the health-related quality of life (HRQOL) status in middle-aged patients with adolescent idiopathic scoliosis (AIS) treated non-surgically. SUMMARY OF BACKGROUND DATA: The HRQOL status using various established questionnaires for non-operated AIS patients has not been fully investigated in long-term follow-up surveys. METHODS: Inclusion criteria were non-surgical treatment for AIS, more than or equl to 30° major scoliosis at skeletal maturity (Risser grade ≥4), and age more than or equl to 30 years at the time of the survey. A total of 107 AIS patients were included and divided into three groups (single main thoracic [MT] curve group; n = 50, single thoracolumbar/lumbar [TL/L] curve group; n = 19, and double-major [DM] curve group; n = 38) based on curve location at skeletal maturity. Age- and sex-matched volunteers were selected as the control group. RESULTS: There were no significant differences in age at survey, body mass index, bone mineral density of the femoral neck, and skeletal muscle mass index among the groups. In all groups, major scoliosis progressed by approximately 0.5°/yr from the time of skeletal maturity to the survey. The thoracolumbar (TL/L) and double-major (DM) groups showed significantly worse visual analog scale scores for low back pain compared with the main thoracice (MT) group (P < 0.05). The all-scoliosis groups showed significantly worse scores for self-image domain of the Scoliosis Research Society Outcome Instrument-22 (SRS-22) than the control group (P < 0.0001). The TL/L group showed significantly worse scores for walking ability and social function domains of the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) (P < 0.05). There were no significant differences in Oswestory Disability Index and Short-Form-12 among the four groups. CONCLUSION: AIS patients with single MT curve maintain equal HRQOL status compared with healthy controls. Patients with structural TL/L curves are likely to experience greater annual TL/L curve progression and have substantial low back pain or worse low back pain-specific HRQOL status during middle age. LEVEL OF EVIDENCE: 4.

Rib Hyperostosis as a Risk Factor for Poor Prognosis in Cervical Spine Injury Patients With Diffuse Idiopathic Skeletal Hyperostosis.

STUDY DESIGN: Retrospective multi-center study. OBJECTIVE: To identify the morphological features of costovertebral joints and ribs in surgically managed cervical injury patients with diffuse idiopathic skeletal hyperostosis (DISH) and to examine its impact on their vital prognosis. SUMMARY OF BACKGROUND DATA: Several reports have indicated that DISH is an independent risk factor for mortality after spinal fracture. The reason for the high mortality in cervical injury patients with DISH is unclear, although some reports have suggested a possible association between pulmonary complications and mortality. METHODS: From 1999 to 2017, a total of 50 DISH patients (44 males) with cervical spine injuries who underwent spinal surgery were enrolled (average age 74 yrs). Prognosis and clinical risk factor data were collected; the morphological features of the patients' costovertebral joints and ribs were evaluated with computed tomography. The influence of each proposed risk factor and thoracic morphological feature on mortality was tested with univariate and multivariate analyses. RESULTS: The survival rate at 5 years after surgery was 52.3%. Nineteen (38%) patients died, and the most common cause of death was pneumonia (68%). Costovertebral bone excrescences and rib hyperostosis were found to be thoracic pathognomonic signs; their frequencies were 94% and 82%, respectively, and these conditions occurred in an average of 7.0 joints and 4.7 bones, respectively. The results of the log-rank test showed a significant difference in age, injury severity score (ISS), costovertebral bone excrescences, and rib hyperostosis. The results of age-adjusted multivariate analysis indicated that age (hazard ratio [HR] = 8.65, 95% confidence interval [CI] = 1.10-68.28, P = 0.041) and rib hyperostosis (HR = 3.82, 95% CI = 1.38-10.57, P = 0.010) were associated with mortality. CONCLUSION: Reduced chest wall mobility associated with rib hyperostosis in cervical spine injury patients with DISH leads to a poor prognosis. LEVEL OF EVIDENCE: 3.