Frailty and Malnutrition as Predictors of Major Complications Following Posterior Thoracolumbar Fusion in Elderly Patients: A Retrospective Cohort Study.

BACKGROUND CONTEXT: The number of elderly patients with degenerative spinal deformity (DSD) is increasing, and posterior thoracolumbar fusion surgery is an effective treatment option, but there are often postoperative major complications, which may hinder the benefit for elderly patients. Currently, there is no consensus on the best risk assessment technique for predicting major complications in elderly patients undergoing long-segment fusion surgery. PURPOSE: This study constructs a risk assessment model using the Modified 5-Item Frailty Index (mFI-5) and serum albumin and evaluates its predictive value. STUDY DESIGN: This is a retrospective analysis of a prospectively established database of DSD. PATIENT SAMPLE: Consecutive patients (aged 65 and older) who underwent open posterior thoracolumbar fusion surgery for DSD between April 2018 and December 2023 were included. OUTCOME MEASURES: Outcome measures included postoperative major complications, length of hospital stay [LOS], readmission and reoperation within 30 days, discharge disposition, physiological function recovery. METHODS: The study reviewed consecutive patients who underwent open posterior thoracolumbar fusion surgery for DSD. Patients were divided into three groups based on the presence or absence of frailty or frailty combined with malnutrition. Spearman ρ analysis was used to assess the correlation between mFI-5 and serum albumin levels. Univariate analyses and multivariate logistic regression were conducted to explore the relationship between frailty and malnutrition defined by mFI-5 and serum albumin and major postoperative complications. Finally, the Receiver Operating Characteristic (ROC) curve was used to evaluate the predictive value of this model for major complications. RESULTS: Compared to the Normal group (n = 59), both the Frailty group (n = 121) and the Frailty and Malnutrition group (n = 50) had higher rates of major complications (21.5% vs. 8.5%, p = .035; 28% vs. 8.5%, p = .002). Multivariate logistic regression showed that frailty and malnutrition status, higher ASA score, and more bleeding were independent predictors of major postoperative complications. The ROC curve demonstrated that frailty combined with malnutrition defined by mFI-5 and serum albumin had a larger area under the curve compared to mFI-5 or serum albumin alone (AUC: 0.676; 95% CI: 1.101-14.129; p < .001). CONCLUSIONS: Compared to considering frailty or malnutrition alone, the combined assessment of frailty and malnutrition using mFI-5 and serum albumin is valuable in predicting major complications in elderly patients undergoing posterior thoracolumbar fusion surgery. LEVEL OF EVIDENCE: III.

Association between delayed ambulation and increased risk of adverse events after lumbar fusion surgery in elderly patients.

PURPOSE: The relationship between delayed ambulation (DA) and postoperative adverse events (AEs) following transforaminal lumbar interbody fusion (TLIF) in elderly patients remains elusive. The aim of our study was to evaluate the effects of DA on the postoperative AEs including complications, readmission and prolonged length of hospital stay (LOS). METHODS: This was a retrospective analysis of a prospectively established database of elderly patients (aged 65 years and older) who underwent TLIF surgery. The early ambulation (EA) group was defined as patients ambulated within 48 h after surgery, whereas the delayed ambulation (DA) group was patients ambulated at a minimum of 48 h postoperatively. The DA patients were 1:1 propensity-score matched to the EA patients based on age, gender and the number of fused segments. Univariate analysis was used to compare postoperative outcomes between the two groups, and multivariate logistic regression analysis was used to identify risk factors for adverse events and DA. RESULTS: After excluding 125 patients for various reasons, 1025 patients (≤ 48 h: N = 659 and > 48 h: N = 366) were included in the final analysis. After propensity score matching, there were 326 matched patients in each group. There were no significant differences in the baseline data and the surgery-related variables between the two groups (p > 0.05). The patients in the DA group had a significant higher incidence of postoperative AEs (46.0% vs. 34.0%, p = 0.002) and longer LOS (p = 0.001). Multivariate logistic regression identified that age, operative time, diabetes, and DA were independently associated with postoperative AEs, whereas greater age, higher international normalized ratio, and intraoperative estimated blood loss were identified as independent risk factors for DA. CONCLUSIONS: Delayed ambulation was an independent risk factor for postoperative AEs after TLIF in elderly patients. Older age, increased intraoperative blood loss and worse coagulation function were associated with delayed ambulation.

The impact of frailty on clinical outcomes of older patients undergoing enhanced recovery after lumbar fusion surgery: a prospective cohort study.

BACKGROUND: Frailty is recognized as a surrogate for physiological age and has been established as a valid and independent predictor of postoperative morbidity, mortality, and complications. Enhanced recovery after surgery (ERAS) can enhance surgical safety by minimizing stress responses in frail patients, enabling surgeons to discharge patients earlier. However, the question of whether and to what extent the frailty impacts the post-ERAS outcomes in older patients remains. MATERIALS AND METHODS: An evidence-based ERAS program was implemented in our center from January 2019. This is a prospective cohort study of patients aged ≥75 years who underwent open transforaminal lumbar interbody fusion (TLIF) for degenerative spine disease from April 2019 to October 2021. Frailty was assessed with the Fried frailty scale (FP scale), and patients were categorized as non/prefrail (FP 0-2) or frail (FP ≥ 3). The preoperative variables, operative data, postoperative outcomes, and follow-up information were compared between the two groups. Univariate and multivariate logistic regression analyses were used to identify risk factors for 90-day major complications and prolonged length of hospital stay after surgery. RESULTS: A total of 245 patients (age of 79.8±3.4 year) who had a preoperative FP score recorded and underwent scheduled TLIF surgery were included in the final analysis. Comparisons between nonfrail and prefrail/frail patients revealed no significant difference in age, sex, and surgery-related variables. Even after adjusting for multiple comparisons, the association between Fried frailty and ADL-dependency, IADL-dependency, and malnutrition remained significant. Preoperative frailty was associated with increased rates of postoperative adverse events. A higher CCI grade was an independent predictor for 90-day major complications, while Fried frailty and MNA-SF scores <12 were predictive of poor postoperative recovery. CONCLUSION: Frail older patients had more adverse post-ERAS outcomes after TLIF compared to non/prefrail older patients. Continued research and multidisciplinary collaboration will be essential to refine and optimize protocols for surgical care in frail older adults.

Development and external validation of a nomogram for predicting postoperative adverse events in elderly patients undergoing lumbar fusion surgery: comparison of three predictive models.

BACKGROUND: The burden of lumbar degenerative diseases (LDD) has increased substantially with the unprecedented aging population. Identifying elderly patients with high risk of postoperative adverse events (AEs) and establishing individualized perioperative management is critical to mitigate added costs and optimize cost-effectiveness to the healthcare system. We aimed to develop a predictive tool for AEs in elderly patients with transforaminal lumbar interbody fusion (TLIF), utilizing multivariate logistic regression, single classification and regression tree (hereafter, "classification tree"), and random forest machine learning algorithms. METHODS: This study was a retrospective review of a prospective Geriatric Lumbar Disease Database (age ≥ 65). Our outcome measure was postoperative AEs, including prolonged hospital stays, postoperative complications, readmission, and reoperation within 90 days. Patients were grouped as either having at least one adverse event (AEs group) or not (No-AEs group). Three models for predicting postoperative AEs were developed using training dataset and internal validation using testing dataset. Finally, online tool was developed to assess its validity in the clinical setting (external validation). RESULTS: The development set included 1025 patients (mean [SD] age, 72.8 [5.6] years; 632 [61.7%] female), and the external validation set included 175 patients (73.2 [5.9] years; 97 [55.4%] female). The predictive ability of our three models was comparable, with no significant differences in AUC (0.73 vs. 0.72 vs. 0.70, respectively). The logistic regression model had a higher net benefit for clinical intervention than the other models. A nomogram based on logistic regression was developed, and the C-index of external validation for AEs was 0.69 (95% CI 0.65-0.76). CONCLUSION: The predictive ability of our three models was comparable. Logistic regression model had a higher net benefit for clinical intervention than the other models. Our nomogram and online tool ( https://xuanwumodel.shinyapps.io/Model_for_AEs/ ) could inform physicians about elderly patients with a high risk of AEs within the 90 days after TLIF surgery.

Comparison of Four Nutritional Screening Tools for Predicting Postoperative Adverse Events Following Degenerative Spinal Deformity Surgery.

STUDY DESIGN: A retrospective study. OBJECTIVE: To compare the mini nutritional assessment-short form (MNA-SF), geriatric nutritional risk index, prognostic nutritional index (PNI), and preoperative serum albumin level as predictors of postoperative adverse events (AEs) in degenerative spine deformity (DSD) patients. SUMMARY OF BACKGROUND DATA: Although various nutritional screening tools have been well evaluated in patients undergoing spinal fusion surgery, the most suitable tool for the DSD population remains uncertain at present. PATIENTS AND METHODS: The authors reviewed consecutive patients who underwent thoracolumbar fusion surgery for DSD between August 2016 and May 2023. Four screening tools were used to assess preoperative nutritional status. Patients were divided into two categories according to each screening tool, and the four screening tools were compared regarding their predictive power for postoperative AEs, including the rates of extended length of hospital stays (LOS), complications, and readmission within three months. Physical functional indicators such as time to first ambulation, nonhome discharge, and postoperative LOS were assessed as secondary outcome measures. A multivariable logistic regression analysis was used to identify factors associated with postoperative AEs. RESULTS: A total of 228 patients were included. The demographic characteristics, underlying disease, and magnitude of correction were not significantly different between well-nourished and malnourished groups. The nutritional risks shown by MNA-SF and albumin level were significantly associated with infectious complications ( P <0.05). The nutritional risk shown by MNA-SF was significantly associated with nonhome discharge, prolonged postoperative LOS (12.5±8.2 vs. 10.3±6.1, P =0.039), and delayed ambulation (3.7±2.1 vs. 2.2±1.8, P =0.001). Multivariable logistic regression revealed that PNI <50 was significantly associated with total AEs and minor AEs after DSD surgery. CONCLUSIONS: PNI was significantly associated with the incidence of total AEs and minor AEs, while preoperative albumin level and MNA-SF were more effective in predicting postoperative infectious complications and delayed recovery of physical function, respectively. LEVEL OF EVIDENCE: Level III.

Development and external validation of a predictive model for prolonged length of hospital stay in elderly patients undergoing lumbar fusion surgery: comparison of three predictive models.

PURPOSE: This study aimed to develop a predictive model for prolonged length of hospital stay (pLOS) in elderly patients undergoing lumbar fusion surgery, utilizing multivariate logistic regression, single classification and regression tree (hereafter, "classification tree") and random forest machine-learning algorithms. METHODS: This study was a retrospective review of a prospective Geriatric Lumbar Disease Database. The primary outcome measure was pLOS, which was defined as the LOS greater than the 75th percentile. All patients were grouped as pLOS group and non-pLOS. Three models (including logistic regression, single-classification tree and random forest algorithms) for predicting pLOS were developed using training dataset and internal validation using testing dataset. Finally, online tool based on our model was developed to assess its validity in the clinical setting (external validation). RESULTS: The development set included 1025 patients (mean [SD] age, 72.8 [5.6] years; 632 [61.7%] female), and the external validation set included 175 patients (73.2 [5.9] years; 97[55.4%] female). Multivariate logistic analyses revealed that older age (odds ratio [OR] 1.06, p < 0.001), higher BMI (OR 1.08, p = 0.002), number of fused segments (OR 1.41, p < 0.001), longer operative time (OR 1.02, p < 0.001), and diabetes (OR 1.05, p = 0.046) were independent risk factors for pLOS in elderly patients undergoing lumbar fusion surgery. The single-classification tree revealed that operative time ≥ 232 min, delayed ambulation, and BMI ≥ 30 kg/m2 as particularly influential predictors for pLOS. A random forest model was developed using the remaining 14 variables. Intraoperative EBL, operative time, delayed ambulation, age, number of fused segments, BMI, and RBC count were the most significant variables in the final model. The predictive ability of our three models was comparable, with no significant differences in AUC (0.73 vs. 0.71 vs. 0.70, respectively). The logistic regression model had a higher net benefit for clinical intervention than the other models. The nomogram was developed, and the C-index of external validation for PLOS was 0.69 (95% CI, 0.65-0.76). CONCLUSION: This investigation produced three predictive models for pLOS in elderly patients undergoing lumbar fusion surgery. The predictive ability of our three models was comparable. Logistic regression model had a higher net benefit for clinical intervention than the other models. Our predictive model could inform physicians about elderly patients with a high risk of pLOS after surgery.

Deep learning-driven diagnosis of multi-type vertebra diseases based on computed tomography images.

Background: Osteoporotic vertebral compression fractures (OVCFs) are the most common type of fragility fracture. Distinguishing between OVCFs and other types of vertebra diseases, such as old fractures (OFs), Schmorl's node (SN), Kummell's disease (KD), and previous surgery (PS), is critical for subsequent surgery and treatment. Combining with advanced deep learning (DL) technologies, this study plans to develop a DL-driven diagnostic system for diagnosing multi-type vertebra diseases. Methods: We established a large-scale dataset based on the computed tomography (CT) images of 1,051 patients with OVCFs from Luhe Hospital and used data of 46 patients from Xuanwu Hospital as alternative hospital validation dataset. Each patient underwent one examination. The dataset contained 11,417 CT slices and 19,718 manually annotated vertebrae with diseases. A two-stage DL-based system was developed to diagnose five vertebra diseases. The proposed system consisted of a vertebra detection module (VDModule) and a vertebra classification module (VCModule). Results: The training and testing dataset for the VDModule consisted of 9,135 and 3,212 vertebrae, respectively. The VDModule using the ResNet18-based Faster region-based convolutional neural network (R-CNN) model achieved an area under the curve (AUC), false-positive (FP) rate, and false-negative (FN) rate of 0.982, 1.52%, and 1.33%, respectively, in the testing dataset. The training dataset for VCModule consisted of 14,584 and 47,604 diseased and normal vertebrae, respectively. The testing dataset consisted of 4,489 and 15,122 diseased and normal vertebrae, respectively. The ResNet50-based VCModule achieved an average sensitivity and specificity of 0.919 and 0.995, respectively, in diagnosing four kinds of vertebra diseases except for SN in the testing dataset. In the alternative hospital validation dataset, the ResNet50-based VCModule achieved an average sensitivity and specificity of 0.891 and 0.989, respectively, in diagnosing four kinds of vertebra diseases except for SN. Conclusions: Our proposed DL system can accurately diagnose four vertebra diseases and has strong potential to facilitate the accurate and rapid diagnosis of vertebral diseases.

Safety and benefit of ambulation within 24 hours in elderly patients undergoing lumbar fusion: propensity score matching study of 882 patients.

BACKGROUND CONTEXT: Elderly patients are less likely to recover from lumbar spine fusion (LSF) as rapidly compared with younger patients. However, there is still a lack of research on the effect of early ambulation on elderly patients undergoing LSF surgery for lumbar degenerative disorders. PURPOSE: To evaluate the safety and benefit of ambulation within 24 hours in elderly patients who underwent LSF. STUDY DESIGN: A retrospective study. PATIENT SAMPLE: Consecutive patients (aged 65 and older) who underwent elective transforaminal lumbar interbody fusion surgery for degenerative disorders from January 2019 to October 2022. OUTCOME MEASURES: Outcome measures included postoperative complications, postoperative drainage (mL), laboratory test data, length of hospital stay [LOS], readmission and reoperation within 3 months. METHODS: Early ambulation patients (ambulation within 24 hours after surgery) were propensity-score matched 1:1 to a delayed ambulation patients (ambulation at a minimum of 48 hours postoperatively) based on age, intraoperative blood loss, and number of fused segments. The incidence of postoperative adverse events (AEs, including rates of complications, readmission, and prolonged LOS) and the average LOS were used to assess the safety and benefit of early ambulation, respectively. Multivariable regression analysis was performed to assess the association between early ambulation and postoperative AEs. The risk factors for delayed ambulation were also determined using multivariable logistic analyses. RESULTS: A total of 998 patients with LSF surgery were reviewed in this study. After excluding 116 patients for various reasons, 882 patients (<24 hours: N=350, 24-48 hours: N=230, and >48 hours: N= 302) were included in the final analysis. After matching, sex, BMI, preoperative comorbidities, laboratory test data and surgery-related variables were comparable between the groups. The incidence of postoperative AEs was significantly lower in the EA group (44.3% vs. 64.0%, p<.001). The average postoperative LOS of the EA group was 2 days shorter than the DA group (6.5 days vs. 8.5 days, p<.001). Patients in the EA group had a significantly lower rate of prolonged LOS compared with the DA group (35.1% vs. 55.3%, p<.001). There was no significant difference in postoperative drainage volumes between the two groups. Multivariable analysis identified older age (odds ratio [OR] 1.07, p<.001), increased intraoperative EBL (OR 1.002, p=.001), and higher international normalization ratio (OR 10.57, p=.032) as significant independent risk factors for delayed ambulation. CONCLUSIONS: Ambulation within 24 hours after LSF surgery is independently associated fewer AEs and shorter hospital stays in elderly patients. Implementing the goal of ambulation within 24 hours after LSF surgery into enhanced recovery after surgery protocols for elderly patients seems appropriate. Older age, increased intraoperative blood loss and worse coagulation function are associated with delayed ambulation.

Compensation Characteristics of Spinal Sagittal Malalignment According to Pelvic Incidence in Elderly Patients with Degenerative Lumbar Spinal Stenosis.

OBJECTIVE: Compensation characteristics of spinal sagittal malalignment according to pelvic incidence (PI) have yet to be elucidated. This study aimed to investigate the difference in compensatory segments according to PI in elderly patients with degenerative lumbar spinal stenosis (DLSS). METHODS: This retrospective study included 196 patients (143 females, 53 males) suffering from DLSS with an average age of 66.73 years in our department. Sagittal parameters were obtained on the whole spinal lateral radiograph, including T1-T12 slope (T1S-T12S), Cobb angle (CA) of the functional units of the thoracic spine, thoracic kyphosis (TK), lumbar lordosis (LL), sacral slope (SS), pelvic tilt (PT), PI, the ratio of PT to PI (PT/PI), PI minus LL mismatch (PI-LL), sagittal vertical axis (SVA). Patients were divided into the low and high PI groups according to the median value of PI. With reference to the value of SVA and PI-LL, each PI group was further grouped into the balance subgroup (SVA < 50 mm, PI-LL ≤10°), hidden imbalance subgroup (SVA < 50 mm, PI-LL > 10°), and imbalance subgroup (SVA ≥50 mm). Independent samples t-test/Mann-Whitney U test, one-way ANOVA/Kruskal-Wallis test, and Person correlation analysis were utilized for statistical test. RESULTS: The median value of PI was 47.65°. 96 and 100 patients were assigned to low and high PI groups, respectively. Correlation analysis indicated that the T8-T12 slope and T10-T12 slope were associated with PI-LL in the high and low PI groups, respectively (all, p < 0.01). For segmental lordosis, T8-9 to T11-12 CA and T10-11 to T11-12 CA were associated with PI-LL in the high and low PI groups, respectively (all, p < 0.01). In the high PI cohort, T8-12 CA and PT increased significantly from the balance to imbalance subgroups (both, p < 0.05). In the low PI cohort, T10-12 CA and PT first increased and then decreased from the balance to imbalance subgroups (both, p < 0.05). CONCLUSION: T8-12 was the main compensatory segment of the thoracic spine in patients with high PI, while it was T10-12 in patients with low PI. In addition, the compensation potential of the lower thoracic spine and pelvis in patients with low PI was inferior to those with high PI.

The effect of sagittal alignment, coronal balance, and segmental stability on preoperative patient-reported outcomes in patients with degenerative lumbar spondylolisthesis.

OBJECTIVE: The aim of this study was to investigate the association between spinal alignment and preoperative patient-reported outcomes (PROs) in patients with degenerative lumbar spondylolisthesis (DLS) and to identify the independent risk factors for worse preoperative PROs. METHODS: In total, 101 patients suffering from DLS were retrospectively studied within a single medical center. Age, sex, height, weight, and body mass index were uniformly recorded. PRO-related indicators include the Oswestry Disability Index (ODI), the Japanese Orthopedic Association's (JOA) score, and the visual analog scale (VAS) for back and leg pain. Sagittal alignment, coronal balance, and stability of the L4/5 level were evaluated through whole-spine anteroposterior and lateral radiographs and dynamic lumbar X-ray. RESULTS: Increasing age (P = 0.005), higher sagittal vertical axis (SVA) (P < 0.001), and global coronal imbalance (GCI) (P = 0.023) were independent risk factors for higher ODI. Patients with GCI had lower JOA scores (P = 0.001) than those with balanced coronal alignment. Unstable spondylolisthesis (P < 0.001) and GCI (P = 0.009) were two vital predictors of VAS-back pain. Increasing age (P = 0.031), local coronal imbalance (LCI) (P < 0.001), and GCI (P < 0.001) were associated with higher VAS-leg pain. Moreover, patients with coronal imbalance also exhibited significant sagittal malalignment based on the subgroup analysis. CONCLUSION: DLS patients with higher SVA, unstable spondylolistheses, a combination of LCI/GCI, or increasing age were predisposed to have more severe subjective symptoms before surgery.

Association between periodontitis and disc structural failure in older adults with lumbar degenerative disorders: A prospective cohort study.

BACKGROUND: Bacterial microbiome as a putative trigger of inflammation might indicate the cascade of mouth-gut-disc axis for causing intervertebral disc (IVD) structural failures (such as IVD degeneration and endplate change) processed. However, direct evidence for the mouth-gut-disc axis still unclear. Therefore, it is interesting to explore periodontal inflammation related to IVD structural failures and clinical outcomes. METHODS: This prospective cohort study enrolled older adults (aged ≥ 75 years) who scheduled to undergo elective open lumbar spine surgery. Demographic, radiological, clinical, and periodontal parameters were recorded. Independent samples t-test and Pearson's correlation analysis were calculated. RESULTS: A total of 141 patients with lumbar degenerative disorders (56 males and 85 females; age 79.73 ± 3.34 years) were divided into edentulous group (19 patients), No/Mild group (84 patients), and Moderate/Severe group (38 patients). The incidence rates of IVD degeneration in each lumbar segmental level based on Pfirrmann grade and endplate change in the fourth and fifth lumbar vertebrae, and Visual Analogue Scale (VAS) low back pain (LBP) and leg pain of patients at preoperative in dentate group was significantly higher compared with edentulous group, especially the comparisons between Moderate/Severe and edentulous groups. There were no significant differences in the range of motion, lumbar lordosis, pelvic incidence, pelvic tilt, sacral slope, and disc height between dentate and edentulous groups. There was a positive association between plaque index (PLI) and pain scores (VAS LBP: r = 0.215, P = 0.030 and VAS leg pain: r = 0.309, P = 0.005), but no significant difference in Oswestry disability index (ODI) score. CONCLUSION: Results show that the severity of periodontitis is associated with higher incidence rates of IVD degeneration and endplate change and clinical outcomes in older adults with lumbar degenerative disorders. Furthermore, the discovery of these relationships unveils a novel mechanism through which the alterations in oral microbiome composition potentially promote IVD degeneration and pain.

Cervical sagittal alignment changes following anterior cervical discectomy and fusion, laminectomy with fusion, and laminoplasty for multisegmental cervical spondylotic myelopathy.

OBJECTIVE: Cervical sagittal alignment changes (CSACs) influence outcomes and health-related quality-of-life. Anterior cervical discectomy and fusion (ACDF), laminectomy with fusion (LCF), and laminoplasty (LP) are common treatments for multisegmental cervical spondylotic myelopathy; however, these approaches need to be compared. METHODS: Our study included 167 patients who underwent ACDF, LCF, or LP. Patients were divided into four groups according to C2-C7 Cobb angle (CL): kyphosis (CL < 0°), straight (0° ≤ CL < 10°), lordosis (10° ≤ CL < 20°), and extreme lordosis (20° ≤ CL) groups. CSACs consist of two parts. CSAC from the preoperative period to the postoperative period is surgical correction change (SCC). CSAC from the postoperative period to the final follow-up period is postoperative lordosis preserving (PLP). Outcomes were evaluated using the Japanese Orthopaedic Association score and the neck disability index. RESULTS: ACDF, LCF, and LP had equivalent outcomes. ACDF had greater SCC than LCF and LP. During follow-up, lordosis decreased in the ACDF and LCF groups but increased in the LP group. For straight alignment, ACDF had greater CSAC and greater SCC than the LCF and LP groups but similar PLP. For lordosis alignment, ACDF and LP had positive PLP, and LCF had negative PLP. For extreme lordosis, ACDF, LP, and LCF had negative PLP; however, cervical lordosis in the LP group was relatively stable during follow-up. CONCLUSIONS: ACDF, LCF, and LP have different CSAC, SCC, and PLP according to a four-type cervical sagittal alignment classification. Preoperative cervical alignment is an important consideration in deciding the type of surgical treatment in CSM.

The ratio of cervical lordosis to C7 slope represents the reciprocal change between cervical sagittal alignment and global spinal alignment.

PURPOSE: This retrospective cross-sectional study investigated variations in the ratio of cervical lordosis to C7 slope (CL/C7S) at different stages of global sagittal balance to better understand how global sagittal alignment affects cervical alignment. METHODS: A total of 255 patients with the degenerative lumbar disease were retrospectively studied within a single medical center. Whole spine radiographs were used to evaluate sagittal parameters, mainly including occiput-C2 lordosis (OC2), cervical lordosis (CL), C7 slope (C7S), the ratio of cervical lordosis to C7 slope (CL/C7S), cervical sagittal vertical axis (CSVA), thoracic kyphosis (TK), lumbar lordosis (LL), pelvic tilt (PT), pelvic incidence (PI), PI minus LL mismatch (PI-LL), and sagittal vertical axis (SVA). Patients were divided into the balance group (SVA < 50 mm, PI-LL ≤ 10°), hidden imbalance group (SVA < 50 mm, PI-LL > 10°), and imbalance group (SVA > 50 mm). RESULTS: Significant correlations were found between CL/C7S and OC2 (r = - 0.334), CSVA (r = - 0.504), PI-LL (r = 0.189), and SVA (r = 0.309). Multivariable linear regression analysis indicated that patients in the hidden imbalance group had lower CL/C7S than those in the balance group (B = - 0.234, P < 0.001), whereas the value of CL/C7S in patients with imbalanced sagittal alignment was higher than those with balanced alignment (B = 0.164, P = 0.011). The mean value of CL/C7S was 0.71, 0.51, and 0.97 in the balance, hidden imbalance, and imbalance groups, respectively. The global spine tended to tilt forward as the LL decreased, while TK, PT, PI-LL, and SVA increased (all, P < 0.001) from the balance stage to the imbalance stage. CONCLUSIONS: CL/C7S tended to be lower when the thoracic extension increased to maintain global sagittal balance at the hidden imbalance stage. Inversely, CL/C7S increased significantly when the global spine showed severe anterior malalignment.

The effect of interlaminar Coflex stabilization in the topping-off procedure on local and global spinal sagittal alignment.

PURPOSE: To investigate the effect of interlaminar Coflex stabilization (ICS) at various segments in the topping-off procedure on local and global spinal sagittal alignment. METHODS: Eighty-nine consecutive patients with degenerative lumbar spinal stenosis (DLSS) who underwent ICS and transforaminal lumbar interbody fusion (TLIF) were retrospectively reviewed. They were divided into Group A (L4-L5 ICS + L5-S1 TLIF), Group B (L3-L4 ICS + L4-S1 TLIF), and Group C (L2-L3 ICS + L3-S1 TLIF) according to their fusion levels. The measured local sagittal parameters included the implanted segmental angle (ISA), intervertebral disc angle (IDA), intervertebral foreman height (IFH), and disc height. The assessed global sagittal parameters included thoracic kyphosis, lumbar lordosis (LL), the fused segment angle (FSA), the sacral slope, the pelvic tilt, pelvic incidence, and the sagittal vertical axis. The Oswestry Disability Index (ODI) and visual analog scales (VAS) were recorded to evaluate the clinical outcomes. RESULTS: Regarding the local alignment parameters, the ISA and IDA decreased immediately after surgery in Groups A and B, followed by an increase at the last follow-up (all, P < 0.05). Conversely, the IFH of Groups A and B first increased after surgery and then decreased to approximately the original value (all, P < 0.05). No significant differences were evident between the local sagittal parameters at different time points in Group C. Regarding the global sagittal profiles, the LL and FSA exhibited a significant postoperative increase (both at P < 0.05) in all the groups. All three groups displayed significant improvements in the ODI, VAS-back pain, and VAS-leg pain. Furthermore, 4.5% (4/89) of the patients exhibited radiographic adjacent segment degeneration (ASD) at the last follow-up. CONCLUSION: ICS during topping-off surgery led to a temporary loss of local lordosis, especially in the lower lumbar segment, while the intervertebral space realigned after middle-term follow-up. The topping-off procedure with ICS is a feasible and promising surgical option of DLSS since it reduces fusion levels and prevents ASD development.

The implementation of enhanced recovery after surgery pathway in patients undergoing posterior thoracolumbar fusion for degenerative spinal deformity.

PURPOSE: The prevalence of degenerative spinal deformity (DSD) and the increased cost of correction surgery impose substantial burdens on the health care and insurance system. The aim of our study was to investigate the effects of the implementation of Enhanced Recovery After Surgery (ERAS) protocol on postoperative outcomes after complex spinal surgery. METHODS: A retrospective analysis of prospectively established database of DSD was performed. The consecutive patients who underwent open correction surgery for degenerative spinal deformity between August 2016 and February 2022 were reviewed. We extracted demographic data, preoperative radiographic parameters, and surgery-related variables. The ERAS patients were 1:1 propensity-score matched to a historical cohort by the same surgical team based on age, gender, BMI, and number of levels fused. We then compared the length of hospital stay (LOS), physiological functional recovery, and the rates of complications and readmissions within 90 days after surgery between the groups. RESULTS: There were 108 patients included, 54 patients in the ERAS cohort, and 54 patients matched control patients in the historical cohort. The historical and ERAS cohorts were not significantly different regarding demographic characteristics, comorbidities, preoperative parameters, operative time, and reoperation rate (P > 0.05). Patients in the ERAS group had significantly shorter postoperative LOS (12.0 days vs. 15.1 days, P = 0.001), average days of drain and urinary catheters placement (3.5 days vs. 4.4 days and 1.9 days vs 4.8 days, respectively), and lower 90-day readmission rate (1.8% vs. 12.9%, P = 0.027). The first day of assisted-walking and bowel movement occurred on average 1.9 days (2.5 days vs. 4.4 days, P = 0.001) and 1.7 days (1.9 days vs. 3.6 days, P = 0.001) earlier respectively in the ERAS group. Moreover, the rate of postoperative urinary retention (3.7% vs. 16.7%, P = 0.026) and surgical site infection (0% vs. 7.4%, P = 0.046) were significantly lower with ERAS protocol applied. CONCLUSIONS: Our study confirmed that the ERAS protocol was safe and essential for patients undergoing thoracolumbar deformity surgery for DSD. The ERAS protocol was associated with a shorter postoperative LOS, a lower rate of 90-day readmission, less rehabilitation discharge, and less postoperative complications.

Preoperative Zung depression scale predicts outcomes in older patients undergoing short-segment fusion surgery for degenerative lumbar spinal disease.

PURPOSE: To identify the relationship between depression measured by Zung depression rating scale (ZDRS) and postoperative outcomes (including the patients reported outcomes [PRO] and clinical outcomes) two years after short-segment fusion surgery for degenerative lumbar spinal disease in older patients (aged 75 years and older). METHODS: We enrolled patients who underwent short-segment fusion surgery for lumbar degenerative disease from May 2018 to June 2020. All patients were assessed for depression using the ZDRS. Patients were included in the depression group and not-depressed group based on their scores. Preoperative baseline data were collected on characteristics, comorbidities, laboratory data, pain levels (visual analogue scale [VAS]), functional status (Oswestry Disability Index [ODI]), and surgery-related variables. The primary outcomes were PRO measures, including VAS, ODI and satisfaction two years after lumbar fusion surgery. Other outcomes included postoperative complications, the length of stay, and reoperation. Univariate and multivariate analyses were performed to identify the risk factors for poor satisfaction. RESULTS: A total of 231 patients (201 in not-depressed and 30 in depressed group) were enrolled in this study. There were no significant differences between the two groups for baseline data. Depressed group had higher rates of choices for dissatisfaction (36.7% vs. 14.0%, p = 0.015), higher VAS scores of low back pain (2.8 ± 2.3 vs. 1.6 ± 1.7, p = 0.012), and worse functional status (31.5 ± 22.5 vs 21.8 ± 19.9, p = 0.015) than the not-depressed group. Depressed patients reported significantly higher rates of postoperative complications and readmissions. Multivariate regression analysis revealed that depression (p = 0.001) was independently associated with postoperative dissatisfaction. CONCLUSION: Preoperative depression was a risk factor for postoperative dissatisfaction, worse functional status, readmission, and complications in older patients undergoing lumbar fusion surgery. Preoperative screening using the Zung depression scale helps inform decision-making when considering fusion surgery for patients aged 75 and older.

Impact of cervical and global spine sagittal alignment on cervical curvature changes after posterior cervical laminoplasty.

OBJECTIVE: To analyze the correlation between the changes in cervical curvature and the sagittal parameters of spino-pelvic and clinical efficacy after posterior laminoplasty (LP). METHODS: The patients with cervical spondylosis treated with LP from June 2018 to December 2020 were reviewed. The preoperative and follow-up spine full-length films were measured. The measured data included C2-C7 Cobb angle, C2-7 sagittal vertical axis (SVA), T1 slope (T1S), pelvic incidence, sacral slope (SS), pelvic tilt (PT), lumbar lordosis (LL), thoracic kyphosis (TK), and C7-SVA. Japanese Orthopaedic Association (JOA) score and neck disability index (NDI) score were recorded before surgery and follow-up. RESULTS: There were 56 patients in this study. There were no significant differences in spino-pelvic sagittal parameters before and after surgery; however, the JOA score significantly improved. The changes in postoperative cervical lordosis correlated with SS, PT, LL, T1S, and C7-SVA (P < 0.05). Regression analysis showed that T1S and C7-SVA were associated with reducing cervical lordosis (P = 0.021 and P = 0.001, respectively). Patients with larger T1S combined with larger C7-SVA had more cervical lordosis loss, poor JOA improvement, and high postoperative NDI scores (P < 0.001, P = 0.018, and P < 0.001, respectively). CONCLUSION: Patients should be examined with full-length spine film before surgery to evaluate the cervical and spino-pelvic sagittal balance. T1S and C7-SVA correlated with changes in cervical sagittal alignment after LP. LEVEL OF EVIDENCE: III.

Paraspinal muscle degeneration and lower bone mineral density as predictors of proximal junctional kyphosis in elderly patients with degenerative spinal diseases: a propensity score matched case-control analysis.

STUDY DESIGN: Retrospective case-control study. OBJECTIVES: Proximal junctional kyphosis (PJK) is a postoperative complication involving the proximal segments which is commonly seen in patients with degenerative spine diseases (DSD). The purpose of the present study was to identify predictive factors for postoperative PJK in elderly patients with DSD. METHODS: We reviewed elderly patients with DSD who underwent thoracolumbar fusion involving no less than 3 levels. Patients who developed PJK were propensity score-matched with patients with DSD who received the same procedure but did not develop PJK. Demographic characteristics, sagittal vertical axis (SVA), computed tomography (CT) value (Hounsfield unit), and paraspinal muscle parameters were compared between PJK and non-PJK groups. RESULTS: Eighty-three PJK and non-PJK patients were selected by propensity score matching for age, sex, history of smoking, body mass index, number of fused segments, and upper instrumented vertebra (UIV) location. SVA showed no significant difference between the two groups. In PJK group, fatty infiltration (FI) in erector spinae and multifidus was significantly greater, while the relative cross-sectional area (rCSA) of erector spinae was significantly smaller than that in non-PJK group. CT value was significantly lower in PJK group. Lower erector spinae rCSA and CT value of the UIV, higher erector spinae FI and multifidus FI were identified as predictors of postoperative PJK. CONCLUSIONS: PJK is a common complication in older patients with DSD. Paraspinal muscle degeneration and low bone mineral density of the UIV are predictors of PJK. Protective measures targeting paraspinal muscles and the UIV may help prevent postoperative PJK.

Changes in T1 slope and cervical sagittal vertical axis correlate to improved neurological function recovery after cervical laminoplasty.

Purpose: To investigate the influence of changes in T1 slope (T1S) and cervical sagittal vertical axis (CSVA) on cervical laminoplasty outcomes. Methods: Eighty-one patients with cervical spondylotic myelopathy (CSM) treated with cervical laminoplasty were enrolled in this study. Demographic parameters included age and follow-up time. Imaging data included occiput-C2 lordosis (OC2), C2-C7 Cobb angle (CL), T1S, CSVA. Outcome assessment indicators included the Japanese Orthopedic Association (JOA) score, JOA recovery rate, and neck disability index (NDI). All patients were grouped based on preoperative T1S and variation in CL after surgery, respectively. Patients with decreased CL postoperatively were further grouped according to whether they were combined with T1S reduction. Results: There were no significant differences in the final JOA score, JOA recovery rate, or NDI between patients with different T1S. Patients with loss of CL postoperatively had lower JOA score and JOA recovery rate, but higher NDI than patients with sustained CL. Furthermore, patients with CL loss but compensate for it with reduction in T1S had lower CSVA, higher JOA score and JOA recovery rate than those with CL loss alone. Conclusions: Decreased T1S postoperatively prevents the tendency of the cervical spine to tilt forward by regulating CSVA and facilitates recovery of neurological function after cervical laminoplasty.

The discrepancy between preoperative cervical sagittal vertical axis and T1 slope predisposes inferior clinical outcomes in patients with cervical spondylotic myelopathy after cervical laminoplasty.

Objective: Cervical sagittal parameters have been widely used to predict clinical outcomes in patients with cervical spondylotic myelopathy (CSM). This study aims to coin a novel cervical sagittal parameter defined as the ratio of cervical sagittal vertical axis to T1 slope (CSVA/T1S) and to investigate the correlation between CSVA/T1S and postoperative HRQOL after laminoplasty. Methods: A total of 102 CSM patients treated with cervical laminoplasty from our database were retrospectively reviewed. All patients were followed up for >12 months. Radiological parameters were measured using lateral cervical radiographs, including occiput-C2 lordosis (OC2), cervical lordosis (CL), CSVA, and T1S. Clinical parameters included the Japanese Orthopedic Association (JOA) score, neck disability index (NDI), and JOA recovery rate. Patients were grouped by preoperative T1S, T1S-CL, and CSVA/T1S value, respectively. Clinical and radiological outcomes were compared between the groups. Results: Patients with high CSVA/T1S had greater OC2 and CSVA but lower CL than those in the low CSVA/T1S group pre-and postoperatively. With respect to HRQOL results, the final NDI was 12.46 ± 9.11% in the low CSVA/T1S group, which was significantly lower than that in the high CSVA/T1S group (17.68 ± 8.81%, P = 0.040). Moreover, only CSVA/T1S was detected to be significantly correlated with final NDI (r = 0.310, P = 0.027). No significant correlation was found between clinical results and other cervical sagittal parameters, including T1S, CSVA, and T1S-CL. Conclusions: Preoperative CSVA/T1S was correlated with postoperative NDI in patients with CSM after cervical laminoplasty. Patients with low preoperative CSVA/T1S achieved better neurological function improvement after cervical laminoplasty. Cervical laminoplasty could be an appropriate choice for patients with lower preoperative CSVA/T1S.