Methods: Ambulatory patients who underwent single-level PVP for thoracolumbar OVF with a follow-up of at least 24 months were retrospectively reviewed. The patients were divided into two groups depending on the presence of symptomatic recollapse at the cemented vertebra: (1) recollapsed (RC) group and (2) noncollapsed (NC) group. The patient characteristics and radiographic measurements associated with sagittal imbalance were analyzed at each follow-up visit. Results: Overall, 134 patients (RC group, n=28; NC group, n=106) were enrolled. The mean fracture-free interval was 3.2 months (range, 1.2–25.1 months). The multivariate binary logistic regression analysis identified low bone mineral density (p =0.047), degree of dynamic mobility within the vertebra (p =0.025), and sagittal imbalance as significant risk factors for recollapse (p =0.013; odds ratio, 5.405). The progression of sagittal imbalance and thoracolumbar kyphosis (T10–L2) was more significant in the RC and sagittal imbalance groups than in the NC group (both p =0.000). Conclusions Sagittal imbalance, lower bone mineral density, and dynamic mobility within the vertebra are associated with the recollapse of cemented vertebrae following PVP. Sagittal imbalance, rather than local kyphosis or thoracolumbar kyphosis, is particularly significant in that it results in more progressive collapse and sagittal deformity and is accompanied by substantial back pain and neurological deficits. Therefore, a stricter and more active management, including anti-osteoporosis medication, is required for the treatment of OVF with sagittal imbalance of the spine.

Background: The purpose of this study was to compare clinical outcomes and complications of primary and revision surgery in patients with adult spinal deformity (ASD) accompanied by sagittal imbalance. Revision surgery has been associated with poor clinical outcomes and increased risk of complications. Previous studies comparing primary versus revision surgery included data for a wide variety of diseases and ages, but few investigated patients with ASD with sagittal imbalance undergoing anterior and posterior combined surgery. Methods: Retrospective cohort analysis of prospectively collected data. We identified 60 consecutive patients with ASD combined with sagittal imbalance who underwent primary or revision surgery; of these, 6 patients were excluded for lack of a minimal 2-year follow-up. Patients’ surgical and radiological data, clinical outcomes, and complications were reviewed. Results: There were 30 patients in the primary group and 24 patients in the revision group. Patient characteristics, including the prevalence of sarcopenia, were similar between the two groups. Pedicle subtraction osteotomy was performed more frequently in the revision group although there was no statistically significant difference between groups. The primary group had more proximal junctional problems, whereas the revision group had more rod breakage (p < 0.05). There were significant improvements in clinical outcomes in both groups when the preoperative and 2-year postoperative values were compared. The Oswestry disability index and visual analog scale score were similar in both groups 2 years postoperatively. Conclusions Considering the greater pain and disability at the time of the revision procedure, revision patients benefited more from surgery at the 2-year follow-up than the primary surgery patients. Complication rates were similar between the groups except for proximal junctional problems and rod breakage. Therefore, revision surgery should not be avoided in the treatment of ASD patients with sagittal imbalance.

Background: The purpose of this study was to compare clinical outcomes and complications of primary and revision surgery in patients with adult spinal deformity (ASD) accompanied by sagittal imbalance. Revision surgery has been associated with poor clinical outcomes and increased risk of complications. Previous studies comparing primary versus revision surgery included data for a wide variety of diseases and ages, but few investigated patients with ASD with sagittal imbalance undergoing anterior and posterior combined surgery. Methods: Retrospective cohort analysis of prospectively collected data. We identified 60 consecutive patients with ASD combined with sagittal imbalance who underwent primary or revision surgery; of these, 6 patients were excluded for lack of a minimal 2-year follow-up. Patients’ surgical and radiological data, clinical outcomes, and complications were reviewed. Results: There were 30 patients in the primary group and 24 patients in the revision group. Patient characteristics, including the prevalence of sarcopenia, were similar between the two groups. Pedicle subtraction osteotomy was performed more frequently in the revision group although there was no statistically significant difference between groups. The primary group had more proximal junctional problems, whereas the revision group had more rod breakage (p < 0.05). There were significant improvements in clinical outcomes in both groups when the preoperative and 2-year postoperative values were compared. The Oswestry disability index and visual analog scale score were similar in both groups 2 years postoperatively. Conclusions Considering the greater pain and disability at the time of the revision procedure, revision patients benefited more from surgery at the 2-year follow-up than the primary surgery patients. Complication rates were similar between the groups except for proximal junctional problems and rod breakage. Therefore, revision surgery should not be avoided in the treatment of ASD patients with sagittal imbalance.

Methods: Patients who completed a questionnaire on back-pain between October 2016 and October 2017 were enrolled in this study. Appendicular skeletal muscle index (ASMI), cross-sectional area (CSA) index, fatty infiltration (FI) rate of the paraspinal muscles, and lumbar extensor strength index (LESI) were measured and compared between no back-pain and back-pain group. Correlations between LESI and ASMI, CSA index, and FI rate were analyzed. The back-pain group was further divided according to ASMI into sarcopenia and non-sarcopenia subgroups and by our newly developed back muscle degeneration risk index based on correlation coefficients between LESI and CSA index, FI rate. Differences in ASMI, CSA index, FI rate, LESI, and Visual Analog Scale (VAS) score between subgroups were analyzed. Results: The ASMI, CSA index, FI rate, and LESI differed significantly between back-pain and pain-free groups. The LESI demonstrated the strongest correlation with FI rate. There were no significant differences in VAS score and back muscle degeneration index in the back-pain group when divided according to the presence of sarcopenia. However, there was a significant difference in VAS score between back-pain patients when classified according to high and low back muscle degeneration risk index. Conclusions We suggest that the degree of back pain is more strongly associated with back muscle degeneration than with sarcopenia. This back muscle degeneration risk index, reflecting both back muscle morphology and function, could be a useful parameter for evaluation of back pain and muscle degeneration.

STUDY DESIGN: Retrospective study. PURPOSE: Associations among risk factors related to adjacent segmental disease (ASD) remain unclear. We evaluated the risk factors and segmental lordosis ratio to prevent ASD developing after lumbar spinal fusion. OVERVIEW OF LITERATURE: Risk factors related to ASD development are age, sex, obesity, pre-existing degeneration, number of fusion segments, and decreased postoperative lumbar lordosis (LL). However, the associations among these factors are still unclear and should be clearly identified. METHODS: We retrospectively reviewed data on 274 patients who underwent lumbar spinal fusion of three segments or below for lumbar degenerative disease from January 2010 to December 2012, with over 5 years of follow-up. Patients with preoperative sagittal vertical axis (SVA) >5 cm were excluded due to sagittal imbalance. A total of 37 patients with ASD and 40 control patients (CTRL) were randomly selected in a similar distribution of matching variables: age, sex, and preoperative degenerative changes. Sex, age, number of fusion segments, radiologic measurements, L4–5–S1/L1–S1 LL ratio, and spinopelvic parameters (pelvic incidence [PI], pelvic tilt [PT], sacral slope [SS], and SVA) were analyzed. Logistic regression was used to analyze the correlation between PI–LL mismatch and L4–5–S1 segmental lordosis rate. RESULTS: No significant difference was found between ASDs and CTRL groups regarding age, sex, number of fusion segments, fusion method, and preoperative and postoperative spinopelvic parameters (PI, SS, PT, and LL). However, regarding the L4–5–S1/L1–S1 lordosis ratio, 50% (p=0.045), 60% (p=0.031), 70% (p=0.042), 80% (p=0.023), and 90% (p=0.023) were statistically significant; <20% (p=0.478), 30% (p=0.223), and 40% (p=0.089) were not statistically significant. In the postoperative PI–LL <10 group, ASD occurred less frequently than in the PI–LL >10 group, and the difference was statistically significant (p=0.048). CONCLUSIONS: Patients with a postoperative L4–5–S1/L1–S1 lordosis ratio >50% had less occurrence of ASD. Correcting LL according to PI and physiologic segmental lordosis ratio is important in preventing ASD.
Animals ; Follow-Up Studies ; Humans ; Incidence ; Logistic Models ; Lordosis ; Methods ; Obesity ; Retrospective Studies ; Risk Factors ; Spinal Fusion

STUDY DESIGN: Retrospective, single-center study. PURPOSE: We aimed to determine the perioperative complications of oblique lumbar interbody fusion (OLIF) as a first-stage procedure in combined anterior and posterior operation for adult spinal deformity (ASD) along with sagittal imbalance. Specifically, we aimed to identify the radiological and clinical types of perioperative surgical complications and the factors affecting these complications. OVERVIEW OF LITERATURE: OLIF has recently gained popularity, and there are several reports of good outcomes and only a few of complications with OLIF; however, a few studies have focused on the perioperative surgical complications of ASD along with sagittal imbalance. METHODS: The perioperative period was a 1-week interval between the anterior and posterior procedures. All patients underwent simple radiography and magnetic resonance imaging preoperatively and postoperatively. Cage placement was evaluated for displacement (i.e., subsidence and migration) and vertebral body fracture. Clinical patient complaints were evaluated perioperatively. Student t-test was used for data analysis. RESULTS: A total of 46 patients were included, totaling 138 fusion segments. A week after OLIF, 14 patients/33 segments (30.4%/23.9%) demonstrated endplate injury-associated cage placement change. Subsidence was the most common cage placement-related complication. As compared with patients without endplate injury, those with endplate injuries showed significantly larger correction angles and a higher proportion of them had larger height cages than the disk height in the full-extension lateral view. Although 32.6% of the patients experienced perioperative clinical complications, they were relatively minor and transient. The most common complication was severe postoperative pain (Visual Analog Scale score of >7), and hip flexor weakness spontaneously resolved within 1 week. CONCLUSIONS: OLIF yielded more than expected endplate injuries from treatment modalities for ASD along with sagittal imbalance. Therefore, surgeons should be cautious about endplate injury during OLIF procedures. It is difficult to accomplish lordosis correction via OLIF alone; therefore, surgeons should not attempt this impractical correction goal and insert an immoderate cage.

STUDY DESIGN: Retrospective study. OBJECTIVES: The purpose of this study was to assess the effect of sagittal spino-pelvic alignment on the clinical symptoms of thoracolumbar kyphosis (TLK; T10-L2 Cobb's angle >20°) in osteoporotic patients. SUMMARY OF LITERATURE REVIEW: Few studies have investigated the clinical symptoms and radiological features of TLK caused by degenerative changes. There is also controversy over whether clinical symptoms will deteriorate in patients with TLK or which treatment should be chosen according to the degree of TLK. MATERIALS AND METHODS: From May 2005 to May 2016, we reviewed 75 patients who were diagnosed with TLK (T10-L2 Cobb's angle >20°) and osteoporosis. Patients were excluded from the study if they had neurological symptoms, underlying spinal disorders, or unstable vertebral fractures. Fifty patients with TLK due to an osteoporotic vertebral compression fracture (group F) and 25 patients with senile TLK (group S) were assessed by clinical symptoms and radiological parameters. Thoracolumbar kyphosis angle and sagittal vertical axis (SVA) were also analyzed. Clinical symptoms were assessed using a visual analogue scale (VAS) and the Oswestry Disability Index (ODI). RESULTS: There were no significant differences in clinical symptoms (VAS, ODI) and radiological parameters between groups F and S, or according to the degree of TLK(20°–30°, 30°–40°, >40°). Clinical symptoms were significantly more severe in patients with sagittal imbalance (SVA >5 cm) than in those with sagittal balance. CONCLUSIONS: Sagittal imbalance is a more important factor affecting clinical symptoms than the cause or the degree of TLK. Therefore, sagittal imbalance should be considered in the management of TLK in osteoporotic patients.
Fractures, Compression ; Humans ; Kyphosis ; Osteoporosis ; Retrospective Studies

STUDY DESIGN: Prospective, single-center study.PURPOSE: The current trend of operative treatment for adult spinal deformity (ASD) is combined anterior-posterior staged surgery. When anterior surgery was first performed, oblique lumbar interbody fusion (OLIF) was employed; this method became increasing popular. This study aimed to determine the lordosis correction that can be achieved using OLIF and assess whether we can preoperatively predict the lordosis correction angle achieved using OLIF.OVERVIEW OF LITERATURE: Many previous studies on OLIF have shown improved clinical and radiologic outcomes. With the increase in the popularity of OLIF, several surgeons have started using larger cages to attain greater lordosis correction. Moreover, some studies have reported complications of OLIF because of immoderate cage insertion. To our knowledge, this is the first prospective study that attempted to determine whether it is possible to predict the lordosis correction angle achieved with OLIF preoperatively, using fullextension lateral view (FELV).METHODS: Forty-six patients with ASD were enrolled. All the operations were performed by a single surgeon in two stages (first, anterior and second, posterior) with a 1-week interval. Radiological evaluation was performed by comparing the Cobb’s angle of the segmental and regional lordosis obtained using preoperative and postoperative simple radiography (including the FELV) and magnetic resonance imaging (MRI).RESULTS: Regional lordosis (L1–S1) in the whole-spine standing lateral radiograph was −3.03°; however, in the supine lateral MRI, it was 20.92°. The regional lordosis of whole-spine standing lateral and supine lateral (MRI) was significantly different. In the FELV, regional lordosis was 25.72° and that in the postoperative supine lateral (MRI) was 25.02°; these values were not significantly different.CONCLUSIONS: Although OLIF offers many advantages, it alone plays a limited role in ASD treatment. Lordosis correction using OLIF as well as lordosis determined in the FELV was possible. Hence, our results suggest that FELV can help predict the lordosis correction angle preoperatively and thus aid the selection of the appropriate technique in the second staged operation.
Adult ; Animals ; Congenital Abnormalities ; Humans ; Leukemia Virus, Feline ; Lordosis ; Magnetic Resonance Imaging ; Methods ; Prospective Studies ; Radiography ; Surgeons

OBJECTIVES: The purpose of this study was to assess the effect of sagittal spino-pelvic alignment on the clinical symptoms of thoracolumbar kyphosis (TLK; T10-L2 Cobb's angle >20°) in osteoporotic patients.SUMMARY OF LITERATURE REVIEW: Few studies have investigated the clinical symptoms and radiological features of TLK caused by degenerative changes. There is also controversy over whether clinical symptoms will deteriorate in patients with TLK or which treatment should be chosen according to the degree of TLK. MATERIALS AND METHODS: From May 2005 to May 2016, we reviewed 75 patients who were diagnosed with TLK (T10-L2 Cobb's angle >20°) and osteoporosis. Patients were excluded from the study if they had neurological symptoms, underlying spinal disorders, or unstable vertebral fractures. Fifty patients with TLK due to an osteoporotic vertebral compression fracture (group F) and 25 patients with senile TLK (group S) were assessed by clinical symptoms and radiological parameters. Thoracolumbar kyphosis angle and sagittal vertical axis (SVA) were also analyzed. Clinical symptoms were assessed using a visual analogue scale (VAS) and the Oswestry Disability Index (ODI). RESULTS: There were no significant differences in clinical symptoms (VAS, ODI) and radiological parameters between groups F and S, or according to the degree of TLK(20°–30°, 30°–40°, >40°). Clinical symptoms were significantly more severe in patients with sagittal imbalance (SVA >5 cm) than in those with sagittal balance. CONCLUSIONS Sagittal imbalance is a more important factor affecting clinical symptoms than the cause or the degree of TLK. Therefore, sagittal imbalance should be considered in the management of TLK in osteoporotic patients.