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.

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.

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.

Preoperative Malnutrition-Associated Spinal Malalignment with Patient-Reported Outcome Measures in Adult Spinal Deformity Surgery: A 2-Year Follow-Up Study.

Introduction: Malnutrition could lead to additional medical complications, and the prognostic nutrition index (PNI) is evaluated to assess the nutritional status of patients. However, the midterm postoperative outcomes of malnutrition in patients with adult spinal deformity (ASD) are unclear. This study aims to investigate postoperative midterm spinal alignment and patients' reported outcome measures (PROMs) in malnourished patients with ASD. Methods: This study recruited 303 ASD patients who underwent surgery. Adult patients ≥50 years old were categorized into the PNI <50 (L group) and the PNI ≥50 (H group) groups. Demographic data, medical complications, mechanical complications, radiographic parameters, Oswestry Disability Index (ODI), and Scoliosis Research Society-22 (SRS-22) were analyzed. Results: In this study, 303 patients participated, with 132 and 171 patients in the L and H groups, respectively. Significant differences were noted between the L and H groups in body mass index (22.5 vs. 23.6 kg/m2, p=0.011), autoimmune disease (9.8% vs. 2.3%, p=0.005), and total number of medical complications (47.7% vs. 33.3%, p=0.011). The T1 slope was significantly higher in the L group than in the H group preoperatively (36.5 vs. 32.8°, p=0.042). However, no significant differences were noted in mechanical complications, ODI, SRS-22 scores, or radiographic parameters 2 years postoperatively between the L and H groups, except for the sagittal vertical axis (73.1 vs. 55.7 mm, p=0.014). Conclusions: No significant difference was noted in the incidence of mechanical complications and PROMs 2 years postoperatively. Malnourished status was related to medical complications and global malalignment. However, good surgical outcomes can be expected even for malnourished patients.

How Is Degenerative Lumbar Scoliosis Associated with Spinopelvic and Lower-Extremity Alignments in the Elderly.

STUDY DESIGN: A retrospective cohort study. PURPOSE: Our aim is to investigate the relationship between degenerative lumbar scoliosis (DLS), and whole-body alignment, including spinopelvic and lower extremity alignments. OVERVIEW OF LITERATURE: DLS is a deformity commonly associated with aging. However, the correlation between whole-body alignment and DLS remains controversial. METHODS: Adult volunteers aged over 50 years were included in the study after participating in the screening program. Characteristic data and standing radiographic parameters were assessed. A propensity score model was established with adjustments for age and sex after a preliminary analysis, and cases were divided into DLS (Cobb angle >10°) and non-DLS (Cobb angle ≤10°) groups. RESULTS: There were significant differences in age, sex, C2 sagittal vertical axis (C2-SVA), C7-SVA, T1 pelvic angle (TPA), lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), PI minus LL (PI-LL), knee angle, ankle angle, pelvic shift, C7-center sacral vertical line, L4 tilt, femur-tibia angle, and hip-knee-ankle angle (all p <0.05) using a preliminary analysis of 261 cases (75 DLS and 186 non-DLS). A one-to-one propensity score-matched analysis was used after 70 pairs of cases were selected. There were no significant differences in the characteristic data for lower extremity parameters. There were still significantly higher values of C2-SVA, TPA, PI, PT, and PI-LL in DLS group than in non-DLS group (all p <0.05). CONCLUSIONS: This study showed an important relationship between DLS and sagittal spinal deformity. However, DLS was not associated with the sagittal and coronal lower extremity alignments.

Perioperative lumbar subarachnoid drainage could not prevent postoperative CSF leakage after spinal cord tumor resection using an artificial dura mater.

BACKGROUND: Cerebrospinal fluid (CSF) leakage occurs in patients who undergo dural repair using artificial dura mater. This study aimed to determine if perioperative lumbar subarachnoid drainage could reduce the incidence of postoperative CSF leakage in cases of dural repair using artificial dura mater. METHODS: We retrospectively analyzed 84 patients (41 men, 43 women; mean age, 52.2 ± 20.1 years) who underwent intradural spinal cord tumor resection and dural repair using artificial dura mater. These patients were divided according to whether they underwent perioperative lumbar subarachnoid drainage (39 patients: D group) or had no drainage (45 patients: ND group). The incidence of radiographic and symptomatic CSF leakage as well as baseline characteristics and operative data were compared between the two groups. RESULTS: Radiographic CSF leakage was observed in 21 patients (25.0%), including 10 (25.6%) in the D group and 11 (24.4%) in the ND group. Symptomatic CSF leakage was observed in 12 patients (14.2%), including six (15,4%) in the D group and 11 (13.3%) in the ND group. There were no significant differences in the incidence of subcutaneous CSF accumulation and symptomatic CSF leakage between the two groups. In cases with symptomatic CSF leakage, the onset time of CSF leakage tended to be earlier (5.7 days vs 15.7 days), and the treatment period tended to be longer (5.8 weeks vs 2.8 weeks) in the ND group than in the D group. CONCLUSIONS: Perioperative lumbar subarachnoid drainage did not reduce the incidence of either radiographic or symptomatic CSF leakage. However, it might shorten the treatment period and reduce refractory CSF leakage, which requires multiple treatments over a long period.

Sex differences between the relationship of trunk muscle mass and whole body sagittal plane alignment in older adults.

BACKGROUND: This study aimed to clarify sex differences in the relationship between trunk muscle mass, aging, and whole-body sagittal alignment. METHODS: Subjects aged 60-89 years who underwent musculoskeletal screening in 2018 were included in the study. Subject demographics, trunk muscle mass (TMM) measured by bioelectrical impedance analysis (BIA), and spinopelvic and lower extremity alignment parameters measured from standing radiographic images were investigated. Additionally, TMM was corrected for BMI (TMM/BMI). The relationship between trunk muscle and whole-body sagittal alignment was analyzed for each age group (young-old group (60-74 years) and old-old group (>75 years)) and sex. RESULTS: A total of 281 (mean age 75.4 ± 6.7 years, 100 males and 181 females) were enrolled. The trunk muscle mass in both men and women significantly decreased with age. Regarding TMM/BMI, there was no significant difference in men, but there was a significant difference between females in the young-old and old-old groups (p < 0.001). TMM/BMI was significantly correlated with sagittal vertical axis (SVA) and knee flexion angle (KF) in both sexes. In females, TMM/BMI was significantly correlated with thoracic kyphosis in the young-old group, whereas in the old-old group, TMM/BMI was correlated with SVA, PI-LL, and KF. CONCLUSIONS: TMM was related to trunk anteverion and lower extremity alignment in both sexes. However, the relationship between TMM on alignment differs between sexes. Thoracic hyperkyphosis in young-old adults indicated a decrease in muscle mass, which may be a sign of future malalignment.

Characteristics of pedicle screw misplacement using freehand technique in degenerative scoliosis surgery.

PURPOSE: This study aimed to estimate the accuracy of pedicle screw (PS) placement in degenerative scoliosis surgery, characterize a patient population with PS misplacement, and analyze the association between misplaced PS vector and lumbar coronal curve. METHODS: In this study, 122 patients (average age 68.6 years), who underwent corrective and decompression surgery, were selected retrospectively. PS accuracy was evaluated in the thoracic to lumbar spine. We identified characteristics of misplacement in each patient. Screw positions were categorized into grade A, entirely in the pedicle; grade B, < 2 mm breach; grade C, 2-4 mm breach; and grade D, > 4 mm breach using postoperative computed tomography. RESULTS: The mean preoperative lumbar coronal curve was 32.3 ± 18.4°, and the number of fused vertebrae was 8.9 ± 2.8. A total of 2032 PS were categorized as follows: grade A, 1897 PS (93.3%); grade B, 67 (3.3%); grade C, 26 (1.3%); and grade D, 43 (2.1%). One PS (grade D), inserted at T5, needed surgery for removal due to neurological deficit. The misplacement group (grades C and D) had a significantly stronger lumbar coronal curve and apical vertebral rotation than the accuracy group (grades A and B). Misplaced PS vector (direction and degree) was significantly correlated with inserted vertebral rotation. Grade D misplacement was distributed mainly around the transitional vertebra of the lumbar curve. CONCLUSIONS: The accuracy of PS insertion in the thoracic to lumbar spine was high in DS surgery, but the need for care was highlighted in the transitional vertebra.

Risk Factors for Cervical Deformity After Posterior Cervical Decompression Surgery: A Multicenter Study.

STUDY DESIGN: Retrospective multicenter study. OBJECTIVE: Posterior decompression surgery for cervical spondylotic myelopathy (CSM) and ossification of the posterior longitudinal ligament (OPLL) is a common surgery; however, it can cause postoperative cervical deformity (CD). The purpose of this study was to investigate the risk factors for CD. METHODS: The participants were 193 patients underwent laminoplasty or laminectomy for CSM or OPLL. CD was defined as a C2-7 sagittal vertical axis (SVA) ≥ 40 mm or a cervical lordosis angle (CL) ≤ -10°. The participants were divided into 2 groups: NCD (without CD before surgery), CD (with CD before surgery). NCD group was divided based on the presence of CD 1 year after surgery as follows: postoperative CD (PCD) and no PCD (NPCD). RESULTS: There were 153 patients (NCD), 40 (CD), 126 (NPCD), and 27 (PCD). There was significant difference in the number of decompressed lamina (NPCD: PCD = 4.1:4.5), the presence of C2 decompression (2: 11%), and C5 palsy (0: 11%). The risk factors for onset of CD, PCD, and CL ≤ -10° as assessed by multiple logistic regression analysis were preoperative C2-7 SVA ≥ 30 mm (odds ratio [OR]: 19.0), decompression of C2 or C7 lamina (OR 3.1), and preoperative CL ≤ 2° (OR 42.0), respectively. CONCLUSIONS: To prevent postoperative CD, it is important to avoid decompression of the C2 or C7 lamina. Moreover, in case with C2-7 SVA ≥ 30 mm or CL ≤ 2° before surgery, it is important to explain the risks and consider adding fusion surgery.