Psychological Factors Can Affect the Clinical Outcome of Chemonucleolysis with Condoliase in Patients with Lumbar Disk Herniation.

Introduction: Condoliase-based chemonucleolysis is a minimally invasive intermediate treatment option between conservative approaches and surgical interventions for lumbar disk herniation (LDH). In this study, the effects of psychological factors on the clinical outcomes of condoliase therapy for LDH were assessed. Methods: This study involved patients with LDH who received condoliase injections over a 1-year follow-up period. Data from the visual analog scale (VAS) scores for leg and back pain, Oswestry Disability Index, and Hospital Anxiety and Depression Scale (HADS), which was utilized for the psychological assessment, were collected. Using magnetic resonance imaging, changes in disk height and degeneration were evaluated. Data were assessed at baseline and 1-month, 3-month, and 1-year follow-ups. Condoliase therapy was considered effective in patients whose VAS score for leg pain improved by ≥50% at 1 year from baseline and who did not require surgery. The patients were divided into two groups: those who reported effective treatment (Group E) and those who did not (Group I). Between these two groups, comparative analyses were carried out. Results: In this study, a total of 102 patients (70 men; mean age, 43.8±18.2 years) were included. Condoliase therapy was effective in 76 patients (74.5%). Thirty-five patients (34.3%) showed psychological factors (HADS-Anxiety [HADS-A]≥8 or HADS-Depression [HADS-D]≥8) preoperatively and had a significantly lower rate of effectiveness than did those without psychological factors. Group I demonstrated significantly higher baseline back pain VAS, HADS, and HADS-D scores when compared with Group E. Logistic regression analysis identified females and the baseline HADS-D score as independent factors that were related to the effectiveness of condoliase therapy. Conclusions: The patients with psychological factors tended to experience residual pain resulting in adverse effects on the clinical outcomes of chemonucleolysis with condoliase.

Evaluation of the changes in waistline asymmetry using digital photography in adolescents with idiopathic thoracolumbar/lumbar scoliosis after corrective surgery.

PURPOSE: Waist line asymmetry is a major cosmetic concern in patients with adolescent idiopathic scoliosis (AIS). The primary surgical goal in patients with AIS is to correct spinal deformities and prevent further progression while maintaining global alignment. Additionally, an important objective of surgical treatment is to address physical appearance by reducing asymmetry. This study aimed to evaluate changes in waistline asymmetry using digital photographs in adolescents with thoracolumbar/lumbar (TL/L) scoliosis who underwent corrective surgery. METHODS: We retrospectively analyzed the data of patients with Lenke types 5C and 6C AIS who underwent posterior fusion surgery with at least 2 years of follow-up. Waist line asymmetry was assessed using digital photography. The waist angle ratio (WAR), waist height angle (WHA), and waistline depth ratio (WLDR) were measured pre- and postoperatively. Radiographic parameters and the revised 22-item Scoliosis Research Society Questionnaire (SRS-22r) were also evaluated. RESULTS: Forty-two patients (40 females and 2 males; 34 with type 5C and 8 with type 6C) were included in the study. The WAR, WHA, and WLDR significantly improved after surgery (0.873 → 0.977, - 2.0° → 1.4°, and 0.321 → 0.899, respectively). Every waistline parameter moderately correlated with the apical vertebral translation of the TL/L curve (WAR: r = - 0.398, WHA: r = - 0.442, and WLDR: r = - 0.692), whereas no correlations were observed with the TL/L curve magnitude. No correlations were observed between the photographic parameters and SRS-22r scores. CONCLUSION: Lateral displacement of the apical vertebra on the TL/L curve correlated with waistline asymmetry. Preoperative waistline asymmetry improved with scoliosis correction. LEVEL OF EVIDENCE: Level 4.

5-year outcomes of surgical intervention in patients with adult spine deformity according to preoperative 5-item modified frailty index scores.

PURPOSE: Frailty increases vulnerability to dependency and/or death, and is important in predicting the risk for adverse effects following adult spinal deformity (ASD) surgery. For easy determination of frailty, the 5-item modified frailty index (mFI-5) was established. However, there are few reports that show the relationship between frailty and mid-term operative outcomes after ASD surgery. The objective of this retrospective study is to determine the correlation of frailty using mFi-5 scores with postoperative medical complications, patient reported outcome measures (PROMs), and radiographic alignment 5 years after ASD surgery. METHODS: 208 patients were divided into robust (R), pre-frail (PF), and frail (F) groups based on mFI-5 scores. Postoperative medical complications, preoperative and 5-year follow-up PROMs and radiographic alignment were evaluated. RESULTS: The study included 91, 79, and 38 patients in group R, PF, and F, respectively. There was no significant difference in age and sex. Discharge to care facility (16 (18%):21 (27%):16 (42%), p = 0.014) and postoperative cardiac complications (2 (2%):0 (0%):3 (8%), p = 0.031) were higher in frail patients. Preoperative ODI (38.3:45.3:54.7, p < 0.001) and SRS-22 (2.7:2.5:2.3, p = 0.004), 5-year postoperative ODI (27:27.2:37.9, p = 0.015), 5-year postoperative SVA (57.8°:78.5°:86.4°, p = 0.039) and 5-year postoperative TPA (23.9°:29.4°:29.5°, p = 0.011) were significantly worse in group F compared to group R. CONCLUSION: Postoperatively, frail patients are more likely to have cardiac complications, inferior PROMs and deterioration of post-correction global spinal alignment. Preoperative assessment using mFI-5 is beneficial to individualize risks, optimize patients, and manage postoperative expectations.

Impact of multi-rod reinforcement on rod fractures in adult spinal deformity: A retrospective case series with a minimum follow up of 5 years.

BACKGROUND: This study aimed to determine the impact of the multi-rod construct on rod fractures over a minimum follow-up period of five years in comparison to that with the conventional two-rod construct using the same technique, rod composition, and rod reinforcement method. METHODS: Data were retrospectively retrieved from a prospectively collected, single-center database. Consecutive patients >50 years of age who underwent thoracopelvic corrective fusion with planned two-stage anterior-posterior surgery and were followed up for at least five years were included in this study. The incidence of rod fracture in the conventional two-rod and multi-rod groups was investigated. RESULTS: A total of 58 patients (mean age, 68.9 years) were included in this study (follow-up rate, 73.4 %). Rod fracture was identified in 25 patients (43.1 %), within an average period of 25.1 months. The incidence of rod fracture in the multi-rod group was significantly lower than that in the two-rod group. However, there was no significant difference in the time to rod fracture between the two groups. Reinforcement of the multi-rod to the distal portion of the connector of the iliac screw had the lowest fracture rate and no cases of reoperation. CONCLUSIONS: The incidence of rod fracture was significantly lower using multi-rod reinforcement, but the timing of rod fracture did not differ, compared to that with the two-rod construct using the same surgical technique and rod material. Multi-rod reinforcement covering the distal portion of the iliac screw is recommended to reduce the risk of fracture and reoperation.

Long-term effects of diffuse idiopathic skeletal hyperostosis on physical function: A longitudinal analysis.

BACKGROUND: Cross-sectional studies on diffuse idiopathic skeletal hyperostosis have focused on its incidence and related factors. However, the long-term changes caused by the disease remain unclear. This longitudinal cohort study aimed to elucidate the progression of diffuse idiopathic skeletal hyperostosis and its effects on physical function, health-related quality of life, and spinal alignment. METHODS: We recruited 255 older adults (87 men and 168 women; average age, 71.3 years in 2014) who attended local health checkups in 2014 and 2020. Height, body weight, body mass index, blood pressure, grip strength, functional reach, and bone mineral density were measured. The prevalence, location, number of ossified contiguous vertebrae, and spinopelvic parameters were estimated using whole-spine standing radiographs. For health-related quality of life assessment, the Oswestry disability index and EuroQuol-5D were obtained. We performed a 1:1 case-control study with age and sex-matched patients with and without diffuse idiopathic skeletal hyperostosis and analyzed progression over a 6-year period. RESULTS: In 2014, 39 (15.3%) of 255 patients were diagnosed with diffuse idiopathic skeletal hyperostosis (24 males and 15 females), which occurred more frequently in the elderly and males. In 2020, 12 (4.3%) patients were newly diagnosed with diffuse idiopathic skeletal hyperostosis, and 28 (71.7%) of 39 patients diagnosed in 2014 showed varying degrees of progression. Compared with age- and sex-matched patients without diffuse idiopathic skeletal hyperostosis, patients with the condition had higher body mass index and lumbar bone mineral density, larger sagittal vertical axis, and greater T1-pelvic angle. Changes in physical function and spinal-pelvic parameters during the 6-year period did not differ between the groups. CONCLUSIONS: Over a 6-year period, the prevalence of diffuse idiopathic skeletal hyperostosis increased by 4.3%, and it progressed in 71.7% of patients. However, it had little effect on longitudinal physical function, health-related quality of life, and spinopelvic parameters in older adults.

The use of lateral lumbar interbody fusion for identifying adult patients with spinal deformities treatable by short corrective fusion in 2-stage surgery.

BACKGROUND: To investigate and compare the surgical outcomes of short and thoracopelvic corrective fusion with our two-stage technique using lateral lumbar interbody fusion (LLIF) and posterior open surgery. METHODS: Consecutive patients with adult spinal deformities who underwent a planned two-stage anterior-posterior surgery, using LLIF for the first stage and posterior open corrective fusion for the second stage, with a minimum of 2 years of follow-up were included. Patients who underwent lumbar or lumbosacral corrective fusion and thoracopelvic corrective fusion were categorized into the short group and thoracopelvic groups, respectively. We investigated the spinopelvic parameters and patient-reported outcome measurements. RESULTS: Seventy-four consecutive patients (8 men, 66 women; average age, 70.0 years) were included. Ten patients underwent short corrective fusion following significant improvements in the symptoms and radiographic parameters post-LLIF. Several preoperative spinopelvic parameters were better in the short group. Compared to the thoracopelvic group, those who underwent short fusion had a poorer alignment 2 years postoperatively but with comparable results and a significantly higher function score on the Scoliosis Research Society-22 r (SRS-22r) questionnaire. The mean Oswestry Disability Index and SRS-22r scores significantly improved during the 2-year postoperative follow-up in both the groups. CONCLUSIONS: Short corrective fusion can be considered in patients whose symptoms and radiographic parameters significantly improve following LLIF. Patients who undergo short fusion with LLIF application have poorer alignment than those who undergo thoracopelvic fusion 2 years postoperatively; however, the results are comparable, and the function score is significantly improved.

Effect of Unintended Tissue Injury on the Development of Thigh Symptoms After Lateral Lumbar Interbody Fusion in Patients With Adult Spinal Deformity: A Retrospective Case Series.

STUDY DESIGN: A retrospective case series. OBJECTIVE: This study aimed to investigate the effects of lateral lumbar interbody fusion (LLIF)-induced unintended tissue damage, including cage subsidence, cage malposition, and hematoma in the psoas major muscle, on the development of thigh symptoms. SUMMARY OF BACKGROUND DATA: Thigh symptoms are the most frequent complications after LLIF and are assumed to be caused by lumbar plexus compression and/or direct injury to the psoas major muscle. However, the causes and risk factors of thigh symptoms are yet to be fully understood. MATERIALS AND METHODS: Adult patients with spinal deformity who underwent two-stage surgery using LLIF and a posterior open fusion for the first and second stages, respectively, were included. Computed tomography and magnetic resonance imaging were routinely performed after LLIF before posterior surgery to investigate cage subsidence, cage malposition, and hematoma in the psoas muscle. We evaluated the development of thigh symptoms after LLIF and examined the effects of tissue injury on the occurrence of thigh symptoms. The differences in demographics and surgical and tissue damage parameters were compared between the groups with and without thigh symptoms using unpaired t tests and chi-squared tests. Factors associated with the development of thigh symptoms and muscle weakness were also assessed using logistic regression analysis. RESULTS: Overall, 130 patients [17 men and 113 women; mean age, 68.7 (range, 47-84)] were included. Thigh symptoms were observed in 52 (40.0%) patients, including muscle weakness and contralateral side symptoms in 20 (15.4%) and 9 (17.3%) patients, respectively. The factors significantly associated with thigh symptoms identified after multiple logistic regression analysis included hematoma (odds ratio: 2.27, 95% CI, 1.03-5.01) and approach from the right side (odds ratio: 2.64, 95% CI, 1.21-5.75). The presence of cage malposition was the only significant factor associated with muscle weakness (odds ratio: 4.12, 95% CI, 1.37-12.4). CONCLUSIONS: We found unintended tissue injury during LLIF was associated with thigh symptoms. We found that hematoma in the psoas major muscle and cage malposition were the factors associated with thigh symptoms and muscle weakness, respectively.

Symptoms of sacral fractures after posterior spinal instrumented fusion: A case series.

BACKGROUND: Improvements in spinal fusion devices and techniques have enabled stronger spinal fusion, resulting in excellent clinical outcomes. Nevertheless, complications associated with implants, such as screw misalignment, screw lubrication, cage dislocation, and skin issues, might occur. This study aimed to investigate the characteristics and symptoms of sacral fractures after spinal instrumented fusion. METHODS: This case series retrospectively examined the medical records of eight patients (one man and seven women; mean age: 74 years) diagnosed with sacral fractures after undergoing posterior spinal instrumented fusion from February 2015 to March 2022. RESULTS: The average number of fusion levels in all patients was 3.5 (range, 1-10). The lowest instrumented vertebrae (LIV) ranged from L5 to the ilium. Sacral fractures were diagnosed at 18.8 (range, 0.5-84) months postoperatively. The average time from consultation to diagnosis was nine days (range, 0-25 days). Two patients had subclinical fractures, two had H-shaped fractures with the LIV at L5, and four had U-shaped fractures, including screw holes. Buttock pain and lower extremity pain, the most commonly reported symptoms, were observed in seven patients each. There were also instances of leg numbness, muscle weakness, and unilateral leg pain that may be related to L5 or S1 radiculopathy. In all patients, leg and buttock pain were worse during movement and in the sitting position, and better while resting and in the supine position. Three patients were treated conservatively, and five were treated with extended fixation to the ilium. CONCLUSIONS: Sacral fractures following posterior spinal fusion can cause radiculopathy and buttock pain. Symptoms are especially severe when instability occurs in the pelvic region, such as during movements or sitting. As atypical radiculopathy may lead to delays in diagnosis, spine surgeons should recognize the symptoms of this condition.

Postoperative neurological complications in intradural extramedullary tumors: A 10-year experience of a single center.

BACKGROUND: Intradural extramedullary spinal cord tumors (IDEMs) cause neurological symptoms due to compression of the spinal cord and caudal nerves. The purpose of this study was to investigate the incidence of postoperative neurological complications after surgical resection of IDEM and to identify factors associated with such postoperative neurological complications. METHODS: We retrospectively analyzed 85 patients who underwent tumor resection for IDEM between 2010 and 2020. We investigated the postoperative worsening of neurological disorders. The patients were divided into two groups: those with and without postoperative neurological complications. Patient demographic characteristics, tumor level, histological type, and surgery-related factors were also compared. RESULTS: The mean age at the time of surgery was 57.4 years, and histological analysis revealed 45 cases of schwannoma, 34 cases of meningioma, three cases of myxopapillary ependymoma, one case of ependymoma, one case of hemangioblastoma and one case of lipoma. There were five cases (5.8%) of postoperative neurological complications, and four patients improved within 6 months after surgery, and one patient had residual worsening. There were no statistically significant differences in age, sex, tumor location, preoperative modified McCormick Scale grade, histology, tumor occupancy, or whether fixation was performed in the presence or absence of postoperative neurological complications. All four cases of meningioma with postoperative neurological complications had preoperative neuropathy and meningiomas were located in the anterior or lateral thoracic spine. CONCLUSIONS: Neurological complications after surgical resection for IDEM occurred in 5.8% of patients. Meningiomas with postoperative neurological complications located anteriorly or laterally in the thoracic spine.

Preoperative Symptom Duration Influences Neurological Recovery and Patient-Reported Outcome Measures After Surgical Treatment of Cervical Ossification of the Posterior Longitudinal Ligament.

STUDY DESIGN: A prospective multicenter study. OBJECTIVE: To investigate the effect of preoperative symptom duration on neurological recovery for the treatment of cervical ossification of the posterior longitudinal ligament (OPLL). SUMMARY OF BACKGROUND DATA: The optimal timing to perform surgery in the setting of cervical OPLL remains unknown. It is important to know the influence of symptom duration on postoperative outcomes to facilitate discussions regarding the timing of surgery. PATIENTS AND METHODS: The study included 395 patients (291 men and 104 women; mean age, 63.7 ± 11.4 yr): 204 were treated with laminoplasty, 90 with posterior decompression and fusion, 85 with anterior decompression and fusion, and 16 with other procedures. The Japanese Orthopedic Association (JOA) score and patient-reported outcomes of the JOA Cervical Myelopathy Evaluation Questionnaire were used to assess clinical outcomes preoperatively and 2 years after surgery. Logistic regression analysis was used to identify factors associated with the achievement of minimum clinically important difference (MCID) after surgery. RESULTS: The recovery rate was significantly lower in the group with symptom duration of ≥5 years compared with the groups with durations of <0.5 years, 0.5 to 1 year, and 1 to 2 years. Improvement of JOA Cervical Myelopathy Evaluation Questionnaire in the upper extremity function score ( P < 0.001), lower extremity function ( P = 0.039), quality of life ( P = 0.053), and bladder function ( P = 0.034) were all decreased when the symptom duration exceeded 2 years. Duration of symptoms ( P = 0.001), age ( P < 0.001), and body mass index ( P < 0.001) were significantly associated with the achievement of MCID. The cutoff value we established for symptom duration was 23 months (area under the curve, 0.616; sensitivity, 67.4%; specificity, 53.5%). CONCLUSIONS: Symptom duration had a significant impact on neurological recovery and patient-reported outcome measures in this series of patients undergoing surgery for cervical OPLL. Patients with symptom duration exceeding 23 months may be at greater risk of failing to achieve MCID after surgery. LEVEL OF EVIDENCE: 3.

Factors Associated With Loss of Cervical Lordosis After Laminoplasty for Patients With Cervical Ossification of the Posterior Longitudinal Ligament: Data From a Prospective Multicenter Study.

STUDY DESIGN: A prospective multicenter study. OBJECTIVE: The objective of this study was to investigate the incidence of loss of cervical lordosis after laminoplasty for cervical ossification of the posterior longitudinal ligament (OPLL). We also sought to determine associated risk factors and the relationship with patient-reported outcomes. SUMMARY OF BACKGROUND DATA: Loss of cervical lordosis is a sequelae often observed after laminoplasty, which may adversely impact surgical outcomes. Cervical kyphosis, especially in OPLL, is associated with reoperation, but risk factors and relationship to postoperative outcomes remain understudied at this time. MATERIALS AND METHODS: This study was conducted by the Japanese Multicenter Research Organization for Ossification of the Spinal Ligament. We included 165 patients who underwent laminoplasty and completed Japanese Orthopaedic Association (JOA) score or Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaires (JOACMEQ), as well as Visual Analog Scales (VAS) for pain, with imaging. The participants were divided into two groups: those with loss of cervical lordosis of >10° or 20° after surgery and those without loss of cervical lordosis. A paired t test was applied to evaluate the association between changes in cervical spinal angles, range of motion, and cervical JOA and VAS scores before and at 2 years postoperatively. Mann-Whitney U test was used for JOACMEQ. RESULTS: Postoperative loss of cervical lordosis >10° and >20° was observed in 32 (19.4%) and 7 (4.2%), respectively. JOA, JOACMEQ, and VAS scores were not significantly different between those with, and without, loss of cervical lordosis. Preoperative small extension range of motion (eROM) was significantly associated with postoperative loss of cervical lordosis, and the cutoff values of eROM were 7.4° [area under the curve (AUC): 0.76] and 8.2° (AUC: 0.92) for loss of cervical lordosis >10° and >20°, respectively. A large occupation ratio of OPLL was also associated with loss of cervical lordosis, with a cutoff value of 39.9% (AUC: 0.94). Laminoplasty resulted in functional improvement in most patient-reported outcomes; however, neck pain and bladder function tended to become worse postoperatively in cases with postoperative loss of cervical lordosis >20°. CONCLUSIONS: JOA, JOACMEQ, and VAS scores were not significantly different between those with, and without, loss of cervical lordosis. Preoperative small eROM and large OPLL may represent factors associated with loss of cervical lordosis after laminoplasty in patients with OPLL.

The relationship between frailty and spinal alignment in the elderly general population: a two-year longitudinal study.

PURPOSE: Frailty is caused by age-related decline in physical function, which may contribute to worsening spinal alignment. Cardiovascular Health Study (CHS)-criteria for assessing physical function seem more appropriate than frailty index which evaluate comorbiduty. However, there have been no reports investigating the relationship between frailty and spinal alignment using the CHS criteria. This study aimed to examine spinal radiographic parameters using the CHS criteria in volunteers participating in a health screening study. METHODS: The subjects were 211 volunteers (71 males and 140 females) aged 60-89 years old who participated in the TOEI study in 2018 and 2020. They were divided into three groups (R: robust, PF: pre-frailty, and F: frailty) according to the score of the Japanese version of the CHS (J-CHS) criteria in 2018. The radiographic parameters were evaluated using a whole-spine standing X-ray. RESULTS: There were 67 volunteers in group R, 124 volunteers in group PF, and 20 volunteers in group F. Of the five items in the J-CHS criteria, low activity was the most common in the PF group (64%). Low activity was also the most common in the F group (100%). Regarding spinal alignment, significant differences were found in C7SVA in 2020 (R:PF:F = 26:31:62 mm, P = 0.047), C2SVA in 2018 (20:34:63 mm, P = 0.019), and C2SVA in 2020 (37:47:78 mm, P = 0.041). CONCLUSION: Frailty was associated with a worsening in global alignment along the 2- year follow up. The frailty may begin with a decrease in activity and progression of exhaustion; preventing this progression is important through motivation to exercise. LEVEL OF EVIDENCE: II.

Clinical differences in preoperative symptoms and surgical outcomes between early and late-teen patients with Lenke type 5C adolescent idiopathic scoliosis.

PURPOSE: This study aimed to compare the clinical features and postoperative outcomes in patients with Lenke type 5C AIS in the early and late teens. METHODS: The study included eligible patients with AIS aged < 20 years with Lenke type 5C curves who underwent selective thoracolumbar/lumbar (TL/L) fusion. The patients were divided into two groups according to the age: younger (11-15 years) and older (16-19 years). Demographic data, radiographic parameters, and 22-item scoliosis research society questionnaire (revised) (SRS-22r) scores were compared. RESULTS: Seventy-three (female: 69, male: 4, mean age: 15.1 years) patients were included. There were 45 and 28 patients in the younger and older groups, respectively. The older group exhibited a significantly smaller TL/L curve than the younger group, whereas no between-group differences were identified regarding curve flexibility and fusion length. The change in coronal balance and subjacent disc angle from preoperative to 2 years after surgery was significantly greater in the younger group, although each curve was equally corrected. Preoperative SRS-22r scores in the older group were significantly worse; however, they improved to the level of the younger group at 2 years after surgery. Postoperative coronal malalignment was observed in six patients (21.4%) in the older group, whereas no cases in the younger group (p < 0.05). CONCLUSION: In patients with Lenke type 5C AIS, we showed that late teens had significantly worse SRS-22r scores than did early teens. Postoperative coronal malalignment was frequently observed in the late teens due to the reduced ability of compensation by subjacent disc wedging.

Occupancy Rate of Pedicle Screw Below 80% is a Risk Factor for Upper Instrumented Vertebral Fracture After Adult Spinal Deformity Surgery.

STUDY DESIGN: Retrospective study. OBJECTIVE: To determine whether an occupancy rate of a pedicle screw (ORPS) <80% in an upper instrumented vertebra (UIV) is a risk factor for UIV fracture (UIVF). SUMMARY OF BACKGROUND DATA: The ratio of the length of the pedicle screw to the anteroposterior diameter of the vertebral body at the UIV is defined as ORPS. Previous studies showed that the stress on the UIV is reduced to the greatest degree when ORPS is >80%. However, it remains unclear whether these results are clinically valid. PATIENTS AND METHODS: A total of 297 patients who had undergone adult spinal deformity surgery were included in the study. The group with an ORPS ≥80% and <80% was defined as the H (n = 198) and L (n = 99) group, respectively. Propensity score matching and logistic regression analysis were used to evaluate the association between ORPS and the development of UIVF adjusting for confounders. RESULTS: The mean age of both groups was 69 years. The average ORPS in the L and H groups was 70% and 85%, respectively. The incidence of UIVF was 30% in group L and 15% in group H ( P < 0.01). In addition, the 99 patients in group H were subdivided into 2 groups according to whether the screws penetrated the anterior wall of the vertebral body: 68 patients had no penetration (group U ), whereas 31 patients showed evidence of penetration (group B ). A total of 10% and 26% of the patients in the U and B groups, respectively, experienced UIVF ( P < 0.05). Logistic regression analysis indicated that ORPS <80% was significantly associated with UIVF ( P = 0.007, odds ratio: 3.9, 95% CI 1.4-10.5). CONCLUSION: To reduce UIVF, screw length should be set with a target ORPS of 80% or higher. If the screw penetrates the anterior wall of the vertebral body, the risk of UIVF is greater.

Optimal lowest instrumented vertebra selection with consideration of coronal and sagittal planes to prevent distal junctional complications in patients with Lenke type 1A and 2A adolescent idiopathic scoliosis.

PURPOSE: Postoperative distal adding-on and distal junctional kyphosis are major distal junctional complications after selective thoracic fusion in patients with adolescent idiopathic scoliosis (AIS). This study aimed to investigate the incidence of distal adding-on and distal junctional kyphosis and evaluate the validity of our selection criteria for the lowest instrumented vertebra (LIV) in patients with Lenke type 1A and 2A AIS. METHODS: We retrospectively analyzed the data of patients with Lenke type 1A and 2A AIS, who underwent posterior fusion surgery. LIV selection included the followings: (1) stable vertebra on traction film, (2) disc space neutralization below the LIV on the side-bending film, and (3) lordotic disc below the LIV on the lateral film. Radiographic parameters and the revised 22-item Scoliosis Research Society Questionnaire (SRS-22r) were evaluated. The incidence of postoperative distal adding-on and distal junctional kyphosis was also investigated. RESULTS: Ninety patients (83 women and 7 men; 64 with type 1A and 26 with type 2A) were included. After the operation, each curve and the SRS-22r of self-image, mental health, and subtotal domains were significantly improved. Distal adding-on occurred in three patients (3.3%, one in type 1A and two in type 2A) at 2 years postoperatively. No patients exhibited distal junctional kyphosis. CONCLUSIONS: Our LIV selection criteria could reduce the incidence of postoperative distal adding-on and distal junctional kyphosis in patients with Lenke type 1A and 2A AIS. LEVEL OF EVIDENCE: Level IV.

Why does knee flexion in the standing position occur? Spinal deformity or knee osteoarthritis.

Background: The interaction between knee osteoarthritis and spinal deformity and knee flexion (KF) remains unclear. We aimed to clarify the relationship between KF in the standing position and the severity of spinal deformity and knee osteoarthritis. Methods: We analyzed older volunteers aged over 60 years who participated in the musculoskeletal screening program. The participant's characteristics and standing radiographic parameters were assessed. After a preliminary analysis, a propensity score-matched model was established with adjustments for age, sex, and body mass index (BMI). Cases were divided into KF (knee angle [KA] ≥10°) and non-KF (KA <10°) groups. Results: In a preliminary analysis of 252 cases (42 KF and 210 non-KF), there were significant differences in age and BMI between the KF and non-KF groups (all p < 0.05). Using a one-to-one propensity score-matched analysis, 38 pairs of cases were selected. There were significantly higher values of C7 sagittal vertical axis, T1 pelvic angle, pelvic tilt, pelvic incidence minus lumbar lordosis, KA, ankle angle, and pelvic shift in the KF group than in the non-KF group (all p < 0.05). In the KF group, 71.1% of the cases had severe spinal deformity (defined as marked deformity by the SRS-Schwab classification), and 31.6% had severe knee osteoarthritis (defined as a Kellgren Lawrence grade ≥3). Of the 31.6%, 7.9% were attributable to knee osteoarthritis alone, and 23.7% to both knee osteoarthritis and spinal deformity. Conclusions: This study clarified that compensatory changes due to spinopelvic malalignment, not due to knee osteoarthritis alone, mainly affected KF in the standing position.

Medical complications following adult spinal deformity correction in patients with autoimmune disease.

OBJECTIVE: An aberrant inflammatory response, which plays a role in the development of postoperative complications, is observed in autoimmune diseases, Yet, there is a paucity of literature regarding the effects of autoimmune diseases after adult spinal deformity (ASD) surgery. The goal of this study was to determine the effects of autoimmune diseases (rheumatoid arthritis, systemic lupus erythematosus) on postoperative medical complications, patient-reported outcome measures (PROMs), and radiographic alignment in patients who underwent ASD surgery. METHODS: Propensity-score matching for age and sex was performed for patients with autoimmune disease (group A) and nonautoimmune patients (group NA1). Postoperative medical complications, preoperative and 2-year follow-up PROMs, and preoperative, immediate postoperative, and 2-year follow-up radiographic alignment were evaluated. RESULTS: Among 386 patients (27 in group A and 359 in group NA1), autoimmune patients had a higher incidence of respiratory complications (11.1% vs 2.2%, p = 0.036), gastrointestinal complications (14.8% vs 3.1%, p = 0.016), urinary tract infections (14.8% vs 3.1%, p = 0.016), cholecystitis (7.4% vs 0%, p = 0.005), and fever of unknown origin (14.8% vs 0%, p < 0.001). Autoimmune patients had worse preoperative ODI (54.2 vs 44.7, p = 0.004) and 2-year follow-up Scoliosis Research Society 22-item Questionnaire (SRS-22) scores (3.1 vs 3.5, p = 0.039), with higher preoperative sacral slope (23.4° vs 17.8°, p = 0.020). Propensity-score matching for age and sex yielded 27 pairs (group A and group NA2). Having at least one medical complication (group A 74.1% vs group NA2 22.2%, p < 0.001), total complications per person (1.3 vs 0.3, p = 0.010), prognostic nutrition index (44.8 vs 48.6, p = 0.034), steroid use (51.9% vs 0%, p < 0.001), immunosuppressant use (48.1% vs 0%, p < 0.001), length of hospital stay (38 vs 27 days, p = 0.018), and discharge to care facility (29.6% vs 7.4%, p = 0.036) were higher in group A. Preoperative ODI (54.2 vs 43.2, p = 0.011) and 2-year follow-up SRS-22 scores (3.1 vs 3.6 p = 0.019) were worse in group A. No differences were observed in radiographic alignment. CONCLUSIONS: Patients with autoimmune disease had higher complication rates and worse PROMs following ASD surgery in this study. There was no difference in spinal alignment compared with controls. Multidisciplinary planning and full disclosure of possible adverse effects should be completed prior to correction of ASD in patients with autoimmune disease.

Effect of corrective stresses on rods in adult spinal deformity surgery-finite element analysis.

BACKGROUND: The incidence of rod fracture after corrective surgery for adult spinal deformity (ASD) is high. Although many reports have investigated the effects of rod bending considering postoperative body motion, and countermeasures, there are no reports investigating the effects during intraoperative correction. The purpose of this study was to investigate the effect of ASD correction on rods by using finite element analysis (FEA) based on the rod shape changes before and after spinal corrective fusion. METHODS: Five ASD patients (mean age 73 years, all female) who underwent thoracic to pelvic fusion were included in this study. A 3D rod model was created using computer-aided design software from digital images of the intraoperatively bended rod and intraoperative X-ray images after corrective fusion. The 3D model of the bent rod was meshed by dividing each of the screw head intervals into 20 sections and cross-section of the rod into 48 sections. Two surgical fusion methods of stepwise fixation as the cantilever method and parallel fixation as the translational method were simulated to evaluate stress and bending moments on the rods during intraoperative correction. RESULTS: The stresses on the rods were 1500, 970, 930, 744, and 606 MPa in the five cases for stepwise fixation and 990, 660, 490, 508, and 437 MPa for parallel fixation, respectively, with parallel fixation having lower stresses in all cases. In all cases, maximum stress was found around the apex of the lumbar lordosis and near L5/S1. The bending moment was high around L2-4 in most cases. CONCLUSIONS: The external forces of intraoperative correction had the greatest effect on the lower lumbar region, especially around the apex of the lumbar lordosis.

Does Adult Spinal Deformity Affect Cardiac Function? A Prospective Perioperative Study.

STUDY DESIGN: Prospective comparative study. OBJECTIVE: The objective of this study was to investigate perioperative cardiac function using echocardiography in patients undergoing surgery for the adult spinal deformity (ASD). SUMMARY OF BACKGROUND DATA: Corrective surgery for ASD has increased, especially in older persons. However, perioperative complication rates remain high in ASD surgery, including cardiopulmonary complications. MATERIALS AND METHODS: This study included patients with ASD who underwent surgery between May 2016 and April 2018. A cardiologist performed all echocardiography imaging preoperatively and 2 weeks postoperatively. Left ventricular contractility was measured using left ventricular ejection fraction (LVEF), and right ventricular contractility was measured using tricuspid annular plane systolic excursion (TAPSE) and tricuspid annular peak systolic velocity (S'). Spinopelvic radiographic parameters, the apices of thoracic kyphosis and lumbar lordosis, and the inflection point where the vertebral curvature changes from kyphosis to lordosis were also measured. Differences between preoperative and postoperative measurements for continuous variables were analyzed using a paired Student t test. Differences in continuous and categorical variables between two independent groups were analyzed using an unpaired Student t test and Fisher exact test, respectively. Multivariate logistic regression analyses were performed to detect influential factors. RESULTS: Sixty-one patients were included [12 males and 49 females; average age, 64.0 (22-84) yr]. LVEF, TAPSE, and S', respectively changed from 64.4%, 24.9 mm, and 14.3 cm/s to 65.4%, 25 mm, and 15 cm/s postoperatively with no significance. However, in LVEF<59.3% (average-1 SD), TAPSE<17 mm, and S'<11.8 cm/s cases, respectively, these increased significantly from 55.7%, 17.9 mm, and 10.5 cm/s to 60.9%, 21.4 mm, and 14.2 cm/s postoperatively ( P =0.036, 0.029, and 0.022, respectively). The LVEF<59.3% group showed a significantly lower inflection point level (1.5 vs. 2.9) preoperatively ( P =0.007). The S'<11.8 cm/s group showed significantly larger thoracic kyphosis (28.3° vs. 19.4°) preoperatively ( P =0.013). CONCLUSIONS: Perioperative cardiac function did not deteriorate after surgery in patients with ASD. In those with lower cardiac function preoperatively, there were significant improvements noted postoperatively. The preoperative inflection point level was significantly lower in the lower LVEF group. Preoperative thoracic kyphosis was significantly larger in the lower tricuspid annular peak systolic velocity group.