Posterior Lumbar Fusion Surgery Research Articles

Preoperative and follow-up variations of psoas major muscle are related to S1 screw loosening in patients with degenerative lumbar spinal stenosis

BackgroundIt was reported the paraspinal muscle played an important role in spinal stability. The preoperative paraspinal muscle was related to S1 screw loosening. But the relationship between preoperative and postoperative change of psoas major muscle (PS) and S1 pedicle screw loosening in degenerative lumbar spinal stenosis (DLSS) patients has not been reported. This study investigated the effects of preoperative and follow-up variations in the psoas major muscle (PS) on the first sacral vertebra (S1) screw loosening in patients with DLSS.Methods212 patients with DLSS who underwent lumbar surgery were included. The patients were divided into the S1 screw loosening group and the S1 screw non-loosening group. Muscle parameters were measured preoperatively and at last follow-up magnetic resonance imaging. A logistic regression analysis was performed to investigate the risk factors for S1 screw loosening.ResultsThe S1 screw loosening rate was 36.32% (77/212). The relative total cross-sectional areas and relative functional cross-sectional areas (rfCSAs) of the PS at L2–S1 were significantly higher after surgery. The increased rfCSA values of the PS at L3–S1 in the S1 screw non-loosening group were significantly higher than those in the S1 screw loosening group. The regression analysis showed male, lower CT value of L1 and longer segment fusion were independent risk factors for S1 screw loosening, and postoperative hypertrophy of the PS was a protective factor for S1 screw loosening.ConclusionsCompared to the preoperative muscle, the PS size increased and fatty infiltration decreased after surgery from L2–3 to L5–S1 in patients with DLSS after short-segment lumbar fusion surgery. Postoperative hypertrophy of the PS might be considered as a protective factor for S1 screw loosening. MRI morphometric parameters and postoperative selected exercise of PS for DLSS patients after posterior lumbar fusion surgery might contribute to improvement of surgical outcome.

Efficacy of Liposomal Bupivacaine in Reducing Opioid Use After Posterior Lumbar Spinal Decompression and Fusion.

Despite improvements in drug therapy and treatment of lumbar spinal disorders, dependence on opioid medication for postoperative pain control remains a concern nationwide. This study assessed the ability to diminish the reliance on opioid medication postoperatively with the Food and Drug Administration-approved local anesthetic liposomal bupivacaine in open posterior lumbar decompression and fusion procedures. In addition, the possible effects of this modality on other parameters were studied regarding patients and their recovery. A retrospective chart review of 198 patients who underwent an open posterior lumbar laminectomy and fusion surgery with instrumentation treated by a single surgeon in a single institution was conducted. Ninety-nine patients who received liposomal bupivacaine administered intraoperatively were then matched by age, sex, and procedure with the same number of patients treated prior to the availability of liposomal bupivacaine. We evaluated how the use of liposomal bupivacaine affected the requirement for postoperative opioid medication, as well as related changes in length of stay, the use of antiemetics, and urinary retention postoperatively. The patients who received liposomal bupivacaine required less than half of the morphine milligram equivalents of narcotic medications during their hospital stay compared with patients who did not receive liposomal bupivacaine (approximately 57% reduction). The findings of this study suggest that the addition of liposomal bupivacaine to traditional pain management modalities can augment pain management for patients undergoing posterior lumbar surgery, as evidenced by the significant decrease in postoperative morphine milligram equivalents required. [Orthopedics. 202x;4x(x):xx-xx.].

High triglyceride-glucose index is associated with low postoperative satisfaction in patients with posterior instrumented lumbar fusion.

This study aimed to determine the effect of the preoperative triglyceride-glucose (TyG) index on the postoperative quality of life, patient satisfaction, and surgical outcomes in patients who underwent posterior lumbar instrumentation and fusion surgery. This was a retrospective single-center cohort study (n = 136). Patients were divided into three groups according to the TyG index: < 25th percentile (L), 25-75 percentile (N), and > 75th percentile (H). Pearson correlation analysis was used to evaluate the relationship between the TyG index and the quantitative variables. Scatterplot and receiver operating characteristic (ROC) curve analysis were used to assess the relationship of the preoperative TyG index with postoperative Oswestry disability index (ODI) and physical function (PF) scores. The TyG index showed a significant correlation with postoperative ODI score. TyG index showed a significant negative correlation with postoperative PF score. On ROC curve analysis, postoperative ODI score ≥ 38 (optimal cut-off) had 79% sensitivity and 92% specificity for predicting high TyG index (group H) (p = 0.016). Postoperative PF score ≤ 80 predicted group H patients with 97% sensitivity and 75% specificity (p = 0.001). The area under the ROC curve was 0.74 (p = 0.016) for the postoperative ODI and 0.79 (p = 0.001) for the postoperative PF. In patients who underwent posterior lumbar instrumentation and fusion surgery, a high preoperative TyG index may predict poor postoperative ODI and PF scores, indicating lower patient satisfaction.

MRI-based central sarcopenia negatively impacts the therapeutic effectiveness of single-segment lumbar fusion surgery in the elderly

Central sarcopenia is associated with the prognosis of various orthopedic surgeries in the elderly. This study aims to investigate its impact on the outcomes of single-segment lumbar fusion surgery in elderly patients. Retrospective analysis was conducted on 314 patients aged 60 to 80 who underwent single-segment posterior lumbar fusion surgery due to degenerative lumbar diseases. Patients were categorized into high psoas and L4 vertebral index (PLVI) and low PLVI groups according to the MRI-measured PLVI for central sarcopenia. Basic patient data, surgery-related parameters, functional assessments at preoperative and postoperative 3, 6, and 12 months, and X-ray-based fusion status were compared. The basic data of the two groups showed no significant differences. Parameters including the operative segment, preoperative hemoglobin levels, surgical duration, and intraoperative blood loss exhibited no significant variances. However, notable differences were observed in postoperative initial hemoglobin levels, transfusion requirements, and length of hospital stay between the two groups. During the postoperative follow-ups at 3, 6, and 12 months, the VAS scores for lower back pain and ODI scores in the lower PLVI group were significantly higher compared to the high PLVI group. Additionally, the EuroQoL 5D scores were notably lower in the low PLVI group. There were no significant differences between the groups in terms of leg pain VAS scores at each time point and the fusion status at 12 months postoperatively. MRI-based central sarcopenia has a negative impact on the therapeutic effectiveness following single-segment lumbar fusion surgery in elderly patients.

A Retrospective Study of Low Molecular Heparin for the Prevention of Postoperative Lower Extremity Thrombosis after Posterior Single-Segment Lumbar Fixation and Fusion Surgery

A Retrospective Study of Low Molecular Heparin for the Prevention of Postoperative Lower Extremity Thrombosis after Posterior Single-Segment Lumbar Fixation and Fusion Surgery

Does the Number of Interbody Devices Affect the Fusion Outcome in Short-Segment Posterior Lumbar Fusion?

Interbody devices (IBDs) have been shown to improve outcomes when used in posterior lumbar fusion (PLF) surgery; however,the exact extent of their clinical benefit remains a current topic of interest. Our primary objective in this study was to identify whether the use of an IBD at every level of fusion construct would affect fusion outcomes such as adjacent segment pathology (ASP) and pseudarthrosis after one- to three-level PLF surgery. This was a single-institution retrospective study. We studied the association of factors such as smoking status, BMI, gender, age, and number of IBDs on the development of ASP and pseudarthrosis. To study the effect of independent variables on ASP and pseudoarthrosis, univariate and multivariate regression analyses were used. The study included 2,061 patients with a history of posterior lumbar fusion who were identified and reviewed. Among these, 363 patients met our inclusion criteria; 247 patients had a minimum follow-up of six months and were finally included in the study. The median follow-up was 30 months. Among the 247 patients, 105 (42.5%) and 24 (9.7%) experienced ASP and pseudarthrosis, respectively. Gender and use of IBD significantly affected the presence of pseudarthrosis (with a higher rate in males and those without any IBDs). Gender, age, BMI, and use of IBDs did not affect ASP. Moreover, using an IBD at each fused level reduced the pseudarthrosis rate significantly compared to when IBDs were not used at all levels (7.3% vs. 27.6%, p <0.001), while there was no significant difference in the rate of ASP (43.6% vs. 34.5%, p = 0.35). In patients undergoing one- to three-level PLF surgery, the use of an IBD at all levels of the fusion construct significantly reduces the rate of pseudarthrosis. There was no significant correlation between the rates of ASP. Studies with a larger sample size and a longer follow-up time are suggested to validate our results for pseudoarthrosis and ASP. Our results suggest the use of an IBD per fusion level in short-segment PLF surgeries.

Incidence and Predictive Factors of New Onset Postoperative Sacroiliac Joint Pain After Posterior Lumbar Fusion Surgery for Degenerative Lumbar Disease.

To explore the incidence and predictive factors of new onset postoperative sacroiliac joint pain (PSJP) after posterior lumbar fusion surgery for degenerative lumbar disease. Three hundred and sixty-seven patient medical records from January 2020 to December 2021 were retrieved. The patients were divided into two groups: PSJP group and N-PSJP (non-postoperative sacroiliac joint pain group). To investigate potential risk factors for PSJP, HU value (Hounsfield unit value) was assessed on CT scans. ImageJ software was used to assess the fat and muscle of the lumbar multifidus muscle (LMM) in the axial MRI image, the red area was marked as fat and the rest were muscles to calculate the ratio of fatty infiltration. Patient characteristics, surgical variables and radiographic parameters were analyzed statistically. Twenty of 367 patients were diagnosed with PJSP at postoperative follow-up. Patients with PSJP presented with significantly higher HU value. For surgical variables, PSJP patients received more operations including distal fusion level at sacrum than the N-PSJP group. For radiographic parameters, most of the patients in the PSJP group had more severe fatty atrophic muscle in the LMM compared to the N-PSJP group. There was no statistically significant difference between the two groups in preoperative and postoperative lumbar lordosis (LL), angle of lumbar lordosis of fixed lumbar vertebrae (FV-LL), pelvic incidence (PI), sacrum slope (SS). The bivariate logistic regression model revealed preoperative fat infiltration rate of the LMM, and higher HU value were independently associated with PSJP. PSJP for degenerative lumbar disease was 5.4%, the predictive factors included preoperative severe infiltration of LMM, distal fusion level at sacrum and higher HU value.

Fat infiltration of the posterior paraspinal muscles is inversely associated with the fat infiltration of the psoas muscle: a potential compensatory mechanism in the lumbar spine

BackgroundThe function of the paraspinal muscles and especially the psoas muscle in maintaining an upright posture is not fully understood. While usually considered solely as a hip flexor, the psoas muscle and its complex anatomy suggest that the muscle has other functions involved in stabilizing the lumbar spine. The aim of this study is to determine how the psoas muscle and the posterior paraspinal muscles (PPM; erector spinae and multifidus) interact with each other.MethodsA retrospective review including patients undergoing posterior lumbar fusion surgery between 2014 and 2021 at a tertiary care center was conducted. Patients with a preoperative lumbar magnetic resonance imaging (MRI) scan performed within 12 months prior to surgery were considered eligible. Exclusion criteria included previous spinal surgery at any level, lumbar scoliosis with a Cobb Angle > 20° and patients with incompatible MRIs. MRI-based quantitative assessments of the cross-sectional area (CSA), the functional cross-sectional area (fCSA) and the fat area (FAT) at L4 was conducted. The degree of fat infiltration (FI) was further calculated. FI thresholds for FIPPM were defined according to literature and patients were divided into two groups (< or ≥ 50% FIPPM).ResultsOne hundred ninetypatients (57.9% female) with a median age of 64.7 years and median BMI of 28.3 kg/m2 met the inclusion criteria and were analyzed. Patients with a FIPPM ≥ 50% had a significantly lower FI in the psoas muscle in both sexes. Furthermore, a significant inverse correlation was evident between FIPPM and FIPsoas for both sexes. A significant positive correlation between FATPPM and fCSAPsoas was also found for both sexes. No significant differences were found for both sexes in both FIPPM groups.ConclusionAs the FIPPM increases, the FIPsoas decreases. Increased FI is a surrogate marker for a decrease in muscular strength. Since the psoas and the PPM both segmentally stabilize the lumbar spine, these results may be indicative of a potential compensatory mechanism. Due to the weakened PPM, the psoas may compensate for a loss in strength in order to stabilize the spine segmentally.

Comprehensive geriatric assessment to predict adverse events in elderly patients undergoing posterior lumbar fusion surgery.

Although comprehensive geriatric assessment (CGA) has been used widely, its impact on adverse events in elderly patients has not been fully examined. The present study aimed to investigate the relationships between subcomponents of CGA and adverse events (AEs) in elderly patients undergoing posterior lumbar fusion surgery. A total of 242 eligible elderly patients enrolled. Our CGA included activities of daily living, instrumental activities of daily living, nutritional status, cardiac function, pulmonary function, renal function, frailty, cognition, anxiety, depression, delirium, chronic pain score, comorbidity and polypharmacy. Comprehensive complication index was used to summarize postoperative complications and its severity. Logistic regression was performed to determine the relationships between subcomponents of a CGA and postoperative AEs. Present study found that female were more vulnerable to have AEs. Postoperative major AEs were associated with delirium (odds ratio (OR): 4.302, 95% confidence interval (CI) 1.720-10.761, p = 0.002), nutritional status (OR: 3.030, 95%CI 1.218-7.541, p = 0.017), cognitive impairment (OR: 4.122, 95%CI 1.179-14.407, p = 0.027), Charlson comorbidity index (CCI) (OR: 4.800, 95%CI 1.852-12.440, p = 0.001) and severe dependent (OR: 3.772, 95%CI 1.116-9.841, p = 0.007). Further analysis showed that delirium (OR: 2.824, 95%CI 1.068-7.467, p = 0.036) and CCI (OR: 3.221, 95%CI 1.184-8.766, p = 0.022) were independently related to major AEs. These results indicate that preoperative screening preoperative delirium, cognitive, nutrition and CCI are essential to prevent postoperative major AEs of the surgical elderly.

Posterior lumbar fusion surgery doesn’t change sexual activities in patients with lumbar degenerative disease: an observational study

BackgroundThere are few studies about sexual function in the patient with posterior lumbar spinal fusion for degenerative lumbar disease. The aim of this study is to investigate sexual activities in patients with lumbar degenerative disease before and after lumbar fusion surgery.MethodsWe recruited 35 patients who underwent lumbar spinal fusion at the age of 55 years or younger. They were 17 men and 18 women with a mean age of 47.4 years. After informed consent, the patients were asked to complete anonymous questionnaire concerning sexual desire, activity, and satisfaction before and after surgery.ResultsIn the presick period, 69% of the patients had sexual desire, and 79% achieved satisfaction during sexual activity. Lumbar degenerative disease decreased sexual desire and frequency of sexual activity in 40%, and 74% respectively. Before surgery, satisfaction in sexual activities decreased in 53%, and 55% of the patients felt discomfort during sexual activity. Adjustment in sexual position was required in 44% of man and 54% of woman. After surgery, Sexual desire, frequency of sexual activity and satisfaction did not regain after surgery in 94%, 93% and 92%, respectively.Those who did not feel discomfort after surgery was significantly lower VAS in both low back pain and leg pain than the patients felt discomfort (low back pain; p = 0.024, leg pain; p = 0.046).ConclusionThis study demonstrated that lumbar degenerative diseases decreased sexual desire, frequency of sexual activity and satisfaction, and little of the patients regained their sexual activities after posterior lumbar fusion surgery in the middle-aged patients.

P32. Preoperative penicillin allergy testing is economically justifiable prior to posterior lumbar fusion surgery

P32. Preoperative penicillin allergy testing is economically justifiable prior to posterior lumbar fusion surgery

Effect of Body Mass Index on Fusion Outcome After Short-Segment Posterior Lumbar Fusion

Obesity is a growing epidemic in the United States. While many adverse effects of obesity on surgical outcome are well studied, a direct correlation among obesity, pseudarthrosis, and adjacent segment pathology is not well defined. In this study we aimed to identify the effect of body mass index (BMI) on pseudarthrosis, adjacent segment pathology (ASP), and reoperation after short-segment (1-3 levels) open posterior lumbar fusion (PLF). This is a retrospective study of patients with degenerative spine pathologies who underwent 1-, 2-, or 3-level PLF surgery between 2010 and 2020. The relevant medical and imaging records were reviewed, and the following variables were recorded: age, gender, BMI, smoking status, surgical details, follow-up length, need for reoperation, indication for reoperation (pseudarthrosis or occurrence of ASP). We included363 patients in our study. Twenty-five patients (6.9%) developed pseudarthrosis, 109 (30%) developed ASP, and 104 patients (28.7%) underwent reoperation for either of these reasons. BMI was significantly less in those who developed pseudarthrosis compared with those who did not (28.6 ± 5.5 vs. 31.2 ± 6.2, respectively; P= 0.04). BMI was not significantly different in those who developed ASP or underwent reoperation compared with those who did not (P= 0.06 and 0.08, respectively). Multivariate regression analysis showed none of the variables in the model (age, gender, tobacco use, BMI, and its classes) significantly predicted pseudarthrosis, ASP, or reoperation (P > 0.1 for all variables). Obese patients undergoing short-segment open PLF have comparable results in terms of pseudarthrosis, ASP, and reoperation.

Development and validation of a risk prediction model for cage subsidence after instrumented posterior lumbar fusion based on machine learning: a retrospective observational cohort study.

Interbody cage subsidence is a common complication after instrumented posterior lumbar fusion surgery, several previous studies have shown that cage subsidence is related to multiple factors. But the current research has not combined these factors to predict the subsidence, there is a lack of an individualized and comprehensive evaluation of the risk of cage subsidence following the surgery. So we attempt to identify potential risk factors and develop a risk prediction model that can predict the possibility of subsidence by providing a Cage Subsidence Score (CSS) after surgery, and evaluate whether machine learning-related techniques can effectively predict the subsidence. This study reviewed 59 patients who underwent posterior lumbar fusion in our hospital from 2014 to 2019. They were divided into a subsidence group and a non-subsidence group according to whether the interbody fusion cage subsidence occurred during follow-up. Data were collected on the patient, including age, sex, cage segment, number of fusion segments, preoperative space height, postoperative space height, preoperative L4 lordosis Angle, postoperative L4 lordosis Angle, preoperative L5 lordosis Angle, postoperative PT, postoperative SS, postoperative PI. The conventional statistical analysis method was used to find potential risk factors that can lead to subsidence, then the results were incorporated into stepwise regression and machine learning algorithms, respectively, to build a model that could predict the subsidence. Finally the diagnostic efficiency of prediction is verified. Univariate analysis showed significant differences in pre-/postoperative intervertebral disc height, postoperative L4 segment lordosis, postoperative PT, and postoperative SS between the subsidence group and the non-subsidence group (p < 0.05). The CSS was trained by stepwise regression: 2 points for postoperative disc height > 14.68 mm, 3 points for postoperative L4 segment lordosis angle >16.91°, and 4 points for postoperative PT > 22.69°. If the total score is larger than 0.5, it is the high-risk subsidence group, while less than 0.5 is low-risk. The score obtains the area under the curve (AUC) of 0.857 and 0.806 in the development and validation set, respectively. The AUC of the GBM model based on the machine learning algorithm to predict the risk in the training set is 0.971 and the validation set is 0.889. The AUC of the avNNet model reached 0.931 in the training set and 0.868 in the validation set, respectively. The machine learning algorithm has advantages in some indicators, and we have preliminarily established a CSS that can predict the risk of postoperative subsidence after lumbar fusion and confirmed the important application prospect of machine learning in solving practical clinical problems.

Incidence, clinical features, and risk factors for acute pancreatitis following posterior instrumented fusion surgery for lumbar degenerative disease: a single-center, retrospective analysis of 20,929 patients.

The aim of this study is to identify the incidence, clinical features, and risk factors for postoperative acute pancreatitis (PAP) after lumbar surgery. We retrospectively analyzed patients who developed PAP after posterior lumbar fusion surgery. For each PAP patient, data were collected for four controls who underwent procedures in the same period and did not develop PAP. Statistical methods included univariate and multivariate analyses. Totally, 21 out of 20,929 patients were diagnosed with PAP (0.10%) after posterior lumbar fusion surgery. Patients with degenerative lumbar scoliosis were at higher risk of developing PAP (P < 0.05). With atypical clinical features, PAP occurred within 3days (0-5) after surgery. PAP patients had significantly higher incidence of osteoporosis (47.6 vs. 22.6%, P = 0.030) and fusion of L1/2(42.9 vs. 4.3%, P = 0.010), lower albumin (42.2 ± 4.1 vs. 44.3 ± 3.2g/L, P = 0.010), more fusion segments (median 4 vs. 3, P = 0.022), larger surgical invasiveness index (median 9 vs. 8, P = 0.007), longer operation duration (232 ± 109 vs. 185 ± 90min, P = 0.041), greater estimated blood loss (median 600 vs. 400mL, P = 0.025), lower intraoperative mean arterial pressure (87.2 ± 9.9 vs. 92.1 ± 8.8mmHg, P = 0.024). Multivariate logistic regression analysis found three independent risk factors: fusion of L1/2, surgical invasiveness index > 8, and intraoperative mean arterial pressure < 90mmHg. All patients were treated with conservative therapy and fully recovered after 8.1 (4-22) days. The incidence of PAP following posterior surgery for degenerative lumbar disease was 0.10%, and its clinical features were not typical. The fusion of L1/2, high surgical invasiveness index, and low intraoperative mean arterial pressure were independent risk factors for PAP after surgery for lumbar degenerative disease.

Association between immediate postoperative hypoalbuminemia and surgical site infection after posterior lumbar fusion surgery.

In this study, we intended to investigate the association between immediate postoperative hypoalbuminemia and surgical site infection (SSI), and determine a threshold value for postoperative hypoalbuminemia that can assist in risk stratification in patients after posterior lumbar fusion surgery. From January 2017 to December 2021, 466 consecutive patients who underwent posterior lumbar fusion surgery were selected to analyze the relationship between immediate postoperative hypoalbuminemia and SSI. Multivariate logistic regression analysis was performed to identify the independent risk factors of SSI and postoperative hypoalbuminemia. Receiver Operating Characteristic (ROC) analysis was used to determine the optimal value for postoperative hypoalbuminemia, and subsequent grouping was based on the identified threshold. Of the total 466 patients, 25 patients (5.4%) developed SSI after surgery, and lower postoperative albumin (OR: 0.716, 95% CI: 0.611-0.840, p < 0.001) was independently associated with SSI. ROC analysis showed that the cutoff value of postoperative hypoalbuminemia was 32g/L with a sensitivity of 0.760, specificity of 0.844, and a Youden index of 0.604. Postoperative SSI was more common in patients with postoperative hypoalbuminemia than in those without (21.6% vs. 1.6%, p < 0.001). Age, gender and operative duration were found to be independent predictors of postoperative hypoalbuminemia. This study showed that immediate postoperative hypoalbuminemia was an independent risk factor for the development of SSI in patients who underwent posterior lumbar fusion. Even in patients with a normal preoperative serum albumin level, there was an increased risk of SSI when the postoperative albumin within 24h was < 32g/L.

The change of Roussouly classification after posterior lumbar fusion surgery.

Roussouly classification is an important morphologic classification which can help to determine high local stress zones of the spine. Different lumbar morphologies of Roussouly type suggest different biomechanics leading to degenerative evolution. This study aimed both to describe the change of the Roussouly classification of the human spine after posterior lumbar fusion surgery and to explore the influencing factors of postoperative Roussouly type. The study is a retrospective case-control study on preoperative and postoperative Roussouly types. A total of 167 patients with lumbar degenerative disease who had undergone short-level transforaminal lumbar interbody fusion surgery between January 2014 and December 2017 in the Department of Orthopedic Surgery, First Affiliated Hospital, Air Force Medical University, were recruited. Preoperative and postoperative general data including gender, age, follow-up time, Oswestry disability index (ODI) score, visual analogue scale (VAS) score, diagnosis, and surgical segment were recorded. Clinical parameters including pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), lumbar lordosis (LL), thoracic kyphosis (TK), and sagittal vertical axis (SVA) were measured using Surgimap software, and the Roussouly classification was assessed. This study included 86 male patients and 81 female patients with a mean age of 52.0±12.4 [14-88] years. The mean follow-up time for these patients was 11.5±6.9 months. The value of sagittal alignment parameters changed after the posterior lumbar fusion surgery, except for the PI value (P=0.591). Roussouly classification changed after surgery. The preoperative Roussouly values of preoperative PI, SS, and LL were significantly different in patients of 4 postoperative Roussouly types. The Roussouly classification changes after posterior lumbar fusion surgery. This change is independent of gender, age, follow-up time, and the number of surgical segments. The preoperative Roussouly type and PI value are essential in predicting one's postoperative Roussouly type.

Three-Dimensional Hounsfield Units Measurement of Pedicle Screw Trajectory for Predicating Screw Loosening in Lumbar Fusion Surgery.

Dual-energy X-ray absorptiometry (DXA) is commonly used for evaluation of bone mineral density before spinal surgery, but frequently leads to overestimation in degenerative spinal diseases due to osteoproliferation factors. We introduce a novel method to compare the predictive ability of Hounsfield Units (HU) and DXA methods to predict screw loosening after lumbar interbody fusion surgery in degenerative spinal diseases by measuring HU of pedicle screw trajectory on computed tomography (CT) images preoperatively. This retrospective study was conducted on patients who underwent posterior lumbar fusion surgery for degenerative diseases. CT HUs measurement was performed using medical imaging software, including the cancellous region on cross-sections of the vertebral body and three-dimensional pedicle screw trajectory. Receiver operating characteristic (ROC) curve analyses were performed for the risk of pedicle screw loosening in association with the Hounsfield scale and preoperative BMD, and the area under the curve (AUC) and the cutoff values were calculated. A total of 90 patients were enrolled and were divided into loosening (n = 33, 36.7%) and non-loosening groups (n = 57, 63.3%). No significant differences in age, gender, length of fixation and preoperative BMD were found between both groups. The loosening group showed lower CT HU values in the vertebral body and screw trajectory than the non-loosening group. Screw trajectory HU (ST-HU) exhibited a higher AUC value than vertebral body HU (B-HU). The cutoff values of B-HU and ST-HU were 160 and 110 HUs, respectively. Three-dimensional pedicle screw trajectory HU values yields a stronger predictive value than vertebral body HU values and BMD and may provide more guidance for surgery. The risk of screw loosening is significantly increased at ST-HU <110 or B-HU <160 at L5 segment.

How Much Blood Loss Is Too Much for a 1-Level Open Lumbar Fusion?

Despite the known association between increased estimated blood loss (EBL) and suboptimal perioperative outcomes, the exact threshold of EBL that impacts outcomes following elective spine surgery remains unknown. In a cohort of patients undergoing elective 1-level open posterior lumbar fusion, we sought to identify EBL thresholds associated with: (1) prolonged length of stay (LOS), (2) postoperative complications, and (3) patient-reported outcomes (PROs). A retrospective, single-center study was performed of patients undergoing elective, 1-level open posterior lumbar fusion with and without interbody fusion between October 2010 and April 2021. The primary exposure variable was EBL. Primary outcomes included: (1) LOS, (2) 30-day complications, and (3) 3-month PROs. Minimum clinically important difference was set at 30% improvement from baseline. For purposes of receiver-operating characteristic curves, LOS was dichotomized as 1 vs ≥2 days. Of the 2028 patients undergoing posterior lumbar fusion surgery, 1183 underwent 1-level fusions, 763 (64.5%) with interbody fusion and 420 (35.5%) without. With interbody fusion: Median (interquartile range [IQR]) EBL was 350 mL (200-600), and median (IQR) LOS was 2 days (2-3). A positive linear association was found between EBL and LOS (P < 0.001) but not with PROs. EBL above 275 mL was associated with LOS beyond postoperative day 1 (POD1) (area under the curve [AUC] = 0.73, 95% CI 0.68-0.78, P < 0.001), with no significant association with overall complications or PROs. Without interbody fusion: Median EBL (IQR) was 300 mL (150-500), and median (IQR) LOS was 3 days (2-4). A positive linear association was found between EBL and LOS (P < 0.001) but not with PROs. EBL above 238 mL was associated with LOS beyond POD1 (AUC = 0.78, 95% CI 0.71-0.85, P < 0.001), with no impact on overall complications or PROs. In patients undergoing 1-level posterior lumbar fusion, EBL volumes greater than 275 and 238 mL in patients with and without interbody fusion, respectively, were associated with increased LOS beyond POD1. No effect was found regarding 30-day complications and 3-month PROs. Although EBL did not directly impact complications or PROs, surgeons may expect longer LOS when higher EBL is reported. EBL above 275 mL with an interbody and 238 mL without an interbody were associated with prolonged LOS beyond POD1 in 1-level open lumbar fusion.

Comparison of Lumbar Fusion Surgical Outcomes Between Patients with Lumbar Spinal Stenosis ≥80 Versus 65-79 Years Old.

BACKGROUND The efficacy of lumbar fusion surgery in patients age 80 years and older with lumbar spinal stenosis (LSS) is still controversial. This retrospective study aimed to evaluate the surgical outcomes of LSS patients ³80 vs 65-79 years. MATERIAL AND METHODS The study included 66 patients diagnosed with LSS from 2014 to 2020; 33 patients were ³80 years and 33 patients were 65-79 years. The 2 groups were matched for sex and surgical segment. All patients underwent posterior lumbar decompression, fixation, and fusion surgery. The Numerical Rating Scale (NRS) of leg and back pain, Oswestry Disability Index (ODI), Short-Form Health Survey (SF-36), and radiographic data were collected before surgery and at 3, 6, and 12 months postoperatively. RESULTS NRS (back) in the ≥80 years group was significantly higher than in the 65-79 years group at 3 months [2 (0-3) vs 1 (0-3), P=0.001]. Improvement of SF-36 (3 months: 15.7±4.9 vs 27.6±5.4, P<0.001; 6 months: 27.3±6.8 vs 31.5±5.6, P=0.011) and Physical Component Score (PCS) (3 months: 6.5±2.5 vs 17.0±3.6, P<0.001; 6 months: 15.9±3.4 vs 20.1±3.1, P<0.001) at 3 and 6 months in the ≥80 years group were significantly smaller than in 65-79 years group. There was a difference of Pfirrmann index of adjacent segment disc between the 2 groups at 12 months [≥80 vs 65-79 years group: 5.5 (4-8) vs 5 (3-8), P=0.003]. CONCLUSIONS Lumbar fusion surgery in patients ≥80 years with LSS can provide comparable improvements in clinical and radiographic outcomes compared with younger patients. Postoperative physiological function recovery was slower in patients ≥80 years.

The treatment effect of posterior lumbar fusion surgery on patients suffering from lumbar disc herniation concurrent with peroneal nerve paralysis.

The purpose of this study is to investigate the clinical effect of posterior lumbar fusion surgery on patients who suffer from lumbar disc herniation concurrent with peroneal nerve paralysis. The patients suffering from peroneal nerve paralysis and undergoing posterior lumbar fusion surgery between January 2012 and December 2019 were retrospectively reviewed. The data of the identified patients were then collected and processed. All patients were followed up post-operatively after discharge from the hospital. The data was analyzed in terms of Oswestry disability index (ODI), visual analogue scale (VAS) score, and relative lower-limb muscle strength. A total of 87 patients (52 males and 35 females) aged 54 ± 11 years met the inclusion criteria for this study. These patients stayed in hospital for 16 ± 6 days and were followed up for 81 ± 24 months. Data analysis showed that muscle strength of the tibialis anterior and extensor digitorum significantly recovered at the last follow-up with a grade of 3 (median), compared to grade 0 at admission (p < 0.001). Furthermore, the median VAS score decreased to 1 at the last follow-up from 6 at admission (p < 0.001), and the ODI greatly improved with 10% (median) at the last follow-up, while it was 58% at admission (p < 0.001). The ODI improvement rate was 60% on average at the last follow-up. Multivariate regression analysis regarding the ODI and muscle strength improvement rates showed that advanced age was a risk factor for postoperative recovery. Most of the patients suffering from lumbar disc herniation concurrent with peroneal nerve paralysis can improve after undergoing posterior lumbar fusion surgery, but few can reach full recovery. Advanced age might be a risk factor that affects the prognosis of these patients after surgery.