Risk factors for persistent numbness following decompression surgery for lumbar spinal stenosis

Predictors of Persistent Postoperative Numbness Following Lumbar Fusion in Patients Older Than 75 Years: A Minimum 2-Year Follow-up

OBJECTIVE

To evaluate the preoperative and perioperative predictors of persistent leg numbness following lumbar fusion in patients aged ≥ 75 years.

METHODS

This single-center retrospective study examined 304 patients aged ≥ 75 years who underwent lumbar fusion for lumbar degenerative disease (102 men, 202 women; mean age, 79.2 [75-90] years). The visual analogue scale (VAS) score for leg numbness was examined preoperatively and at 2 years postoperatively. The persistent leg numbness group included patients with a 2-year postoperative VAS score for leg numbness ≥ 5 points. The demographic data were also reviewed. A multivariate stepwise logistic regression analysis was performed for variables with univariate analysis values of p < 0.2 on univariate analysis.

RESULTS

In total, 71 patients (23.4%) experienced persistent postoperative leg numbness. Multivariate logistic regression analysis revealed that a history of lumbar decompression, longer symptom duration, and a preoperative VAS score for leg numbness ≥ 5 points were associated with greater postoperative persistent leg numbness following lumbar fusion. In contrast, other factors, such as sex, body mass index, vertebral fracture, diabetes mellitus, depression, symptom duration, dural injury, operative time, and estimated blood loss, were not.

CONCLUSION

A history of preoperative lumbar decompression, longer symptom duration, and greater preoperative VAS scores for leg numbness were preoperative predictors of persistent postoperative leg numbness following lumbar fusion in older patients. Although lumbar fusion is expected to improve leg numbness, surgeons should consider the surgical history, duration, and preoperative numbness intensity and explain the potential postoperative persistent leg numbness in advance.

Prognostic factors for residual symptoms following percutaneous endoscopic lumbar discectomy

To explore the risk factors for residual symptoms following percutaneous endoscopic lumbar discectomy (PELD). A retrospective case-controlled study. From January 2015 to December 2020, consecutive patients who underwent PELD for lumbar disc herniation (LDH) in our department were retrospectively studied. All the patients were followed-up at least two years. Residual symptoms were analyzed for association with baseline data, clinical feature, physical examination, and radiographic characteristics, which were used to detected the risk factors. A total of 339 patients were included in this study, with a mean follow-up of 28.7 ± 3.6 months. Of the enrolled patients, 90 (26.5%) patients experienced residual low back pain (LBP), and 76 (22.4%) patients experienced leg numbness (LN). Multivariate logistic regression analysis revealed that intervertebral disc calcification on CT scans (odd ratio, 0.480; 95% confidence interval: 0.247 ~ 0.932; P < 0.05) was independent risk factor for postoperative residual LBP with odd ratio and longer symptom duration was risk factor for postoperative residual LN (odd ratio, 2.231; 95% confidence interval:1.066 ~ 4.671; P < 0.05). Residual symptoms following transforaminal endoscopic surgery are quite prevalent. Intervertebral disc calcification is a protective factor for residual low back pain, and a longer symptom duration is a risk factor for residual leg numbness.

Risk factors for postoperative complaints in patients following lumbar decompression and fusion: Analyses focusing on preoperative symptoms

BACKGROUND

Several patients complained of residual symptoms following lumbar decompressive surgery for lumbar degenerative disease (LDD). However, few studies analyze this dissatisfaction by focusing on preoperative patients' symptoms. This study was conduct to determine the factors that could predict the patients' postoperative complaints by focusing on their preoperative symptoms.

METHODS

Four hundred and seventeen consecutive patients who underwent lumbar decompression and fusion surgery for LDD were included. Postoperative complaint was defined by at least twice same complaint during the outpatient follow-up of 6,12, 18 and 24 months after surgery. A comparative analysis was performed between complaint group (group C, N = 168) and non-complaint group (group NC, N = 249). Demographic, operative, symptomatic, and clinical factors were compared between the groups by univariate and multivariate analyses.

RESULTS

The main preoperative chief complaints were radiating pain (318/417, 76.2%). However, most common postoperative complaint was residual radiating pain (60/168, 35.7%) followed by tingling sensation (43/168, 25.6%). The presence of psychiatric disease (adjusted odds ratio [aOR], 4.666; P = 0.017), longer pain duration (aOR, 1.021; P < 0.001), pain to below the knee (aOR, 2.326; P = 0.001), preoperative tingling sensation (aOR, 2.631; P < 0.001), preoperative sensory and motor power decrease (aOR, 2.152 and 1.678; P = 0,047 and 0.011, respectively) were significantly correlated with postoperative patients' complaints in multivariate analysis.

CONCLUSIONS

The postoperative patients' complaints could be predicted and explained in advance by checking the preoperative characteristics of patients' symptoms, including the duration and site carefully. This could be helpful to enhance the understanding of the surgical results preoperatively, which could control the anticipation of the patients.

Balancing ability of patients with lumbar spinal canal stenosis

PURPOSE

To determine the relationship between postural sway and the severity of lumbar spinal canal stenosis as well as the effect on postoperative improvement.

METHODS

Stabilometry was performed before and 6 months after surgery in 52 patients (29 men and 23 women; mean age, 74.1 ± 7.8 years) who underwent decompression surgery for lumbar spinal canal stenosis. The environmental area (EA; the area surrounding the circumference of the stabilogram) and locus length per EA (L/EA) were evaluated. The patients were divided into moderate (n = 22) and severe (n = 30) groups according to the severity of canal stenosis. Patient characteristics and parameters were compared between the groups before and after surgery, including the visual analog scale (VAS) score for leg pain, Oswestry Disability Index (ODI), EA, and L/EA. In addition, factors affecting EA and L/EA were evaluated using multiple regression analysis.

RESULTS

Age (p = 0.031), preoperative EA (p < 0.001), preoperative L/EA (p = 0.032), and sagittal vertical axis (p = 0.033) were significantly different between groups. The VAS score and ODI significantly improved postoperatively in both groups (p < 0.001). The EA significantly improved postoperatively only in the severe group (p < 0.001), whereas the L/EA did not significantly improve in either group. Multiple regression analysis showed that only the severity of canal stenosis was significantly associated with preoperative EA (p = 0.030), whereas age (p = 0.040) and severity of canal stenosis (p = 0.030) were significantly associated with preoperative L/EA. Diabetes was significantly associated with postoperative EA (p = 0.046) and L/EA (p = 0.030).

CONCLUSION

The severity of canal stenosis affected abnormal postural sway, which improved after decompression surgery.

Effect of Lower Extremity Osteoarthritis on Outcomes of Lumbar Decompression

BACKGROUND

The purpose of this study is to evaluate how hip or knee osteoarthritis (OA) and total joint arthroplasty impact the outcomes of patients undergoing lumbar decompression.

METHODS

A retrospective review of 342 patients undergoing lumbar decompression without fusion from January 2019 and June 2021 at a single institution was performed. Univariate and multivariate analyses were used to compare outcomes between patients with and without concomitant hip or knee OA.

RESULTS

Forty-six percent of patients had a hip or knee OA diagnosis and were higher risk as they were older, had higher BMIs, were more likely to be former smokers, had higher ASA scores, and were more likely to undergo 3+ level surgery. Postoperatively, after adjusting for differences between groups, hip or knee OA patients were more likely to be readmitted (OR=12.45, p=0.026) or have a complication (OR=13.77, p=0.031). However, patient reported outcomes as measured by Patient Reported Outcomes Measurement Information System-physical function. were similar at 1-3 months and 3-6 months. Higher levels of physical function were observed at 3-6 months postoperatively in hip OA patients with a history of THA.

CONCLUSION

Patients with concomitant hip or knee OA are at higher risk for readmission and postoperative complications but may achieve similar levels of physical function as those without OA.

Characteristics of the Patients with Poor Clinical Outcomes After Symptomatic Postoperative Lumbar Epidural Hematoma

OBJECTIVE

Symptomatic postoperative lumbar epidural hematoma (PLEH) may lead to poor outcomes even after evacuation. This study aimed to verify the short-term clinical outcomes after the evacuation of PLEH and to clarify the characteristics of the patients with poor postoperative outcomes.

METHODS

Twenty-five patients (average age; 70.4 years) underwent PLEH evacuation after lumbar spine surgery. The mean follow-up period was 12.0 (range 3-37) months. Pre and postoperative Japanese Orthopedic Association scores and visual analog scale (VAS) of low back pain (LBP), leg pain, and leg numbness were retrospectively collected. The dural sac cross-sectional area at the most compressed level was measured on magnetic resonance imaging. The patients were classified into 2 groups: poor outcome group (P group) had less than 50% of Japanese Orthopedic Associationrecovery rate and good group (G group) with 50% or more recovery rate.

RESULTS

The rate of delayed evacuation (over 24 hours of onset) was significantly higher in P group than in G group (P = 0.027). There was no significant difference in dural sac cross-sectional areabetween the 2 groups (P = 0.438). VAS of LBP, leg pain, and leg numbness in G group significantly improved postoperatively. Although VAS of LBP and leg pain in P group significantly improved postoperatively, there was no significant difference between the pre and postoperative VAS of leg numbness.

CONCLUSIONS

Delayed evacuation of PLEH can lead to poor postoperative outcomes after lumbar spine surgery. Moreover, patients with poor outcomes remained with postoperative leg numbness. Early evacuation of symptomatic PLEH is key to avoid poor outcomes and persistent leg numbness.

Delta large-channel technique versus microscopy-assisted laminar fenestration decompression for lumbar spinal stenosis: a one-year prospective cohort study

PURPOSE

When it comes to treating lumbar spinal stenosis (LSS), a procedure known as microscope-assisted fenestration decompression has expediently become the gold standard. With the advancement of spinal endoscopy, the Delta large-channel approach has shown promising clinical outcomes in the management of lumbar spinal stenosis. However, case studies of this method being used to treat lumbar spinal stenosis are still uncommon. The purpose of this research was to examine how well microscopy-assisted laminectomy and the Delta large-channel approach work in treating LSS in the clinic.

METHODS

From May 2018 to June 2020, 149 patients diagnosed with LSS were divided into 80 patients in Delta large-channel technique groups (FE group) and 69 patients in microscope groups (Micro group). Lower back and lower limb pain were measured using the visual analogue scale (VAS-LBP and VAS-LP), while lower limb numbness was evaluated using the 11-point numerical rating scale (NRS-LN); modified Oswestry Disability Index (ODI) was used to evaluate the quality of life, and modified MacNab criteria were used to assess the clinical efficacy before surgery and at one week, three months, six months, and 12 months after surgery. All patients had single-level lumbar spinal stenosis, and clinical data such as hospital stay, operation time, intraoperative blood loss were statistically analyzed.

RESULTS

Finally, 111 patients (62 in FE group and 49 in Micro group) completed follow-up. Compared with preoperative results, postoperative VAS-LBP, VAS-LP, NRS-LN score and modified ODI score were significantly improved in 2 groups (P < 0.05), but there was no significant difference in postoperative follow-up at each time point (P > 0.05), Except 1 week after surgery, VAS-LBP in FE group was lower than that in Micro group (P < 0.05). It is noteworthy that the FE group had a shorter hospital stay, less intraoperative blood loss, and a quicker time of getting out of bed when compared with the microscope group，but the operation time was just the opposite (P < 0.05). The excellent and good rate was 83.87% in FE group and 85.71% in Micro group (P > 0.05).

CONCLUSIONS

Both microscope-assisted laminar fenestration decompression and Delta large-channel procedures provide satisfactory treatment outcomes, however the Delta large-channel approach has some potential advantages for the treatment of LSS, including quicker recovery and sooner reduced VAS-LBP. Long-term consequences, however, will necessitate additional follow-up and research.

Risk Factors in the Prediction of Leg Numbness after Spinal Endoscopic Surgery: Evaluation and Development of a Nomogram

Purpose

This study aims at constructing a clinical predictive model that predicted the risk factors for leg numbness after spinal endoscopic surgery.

Methods

We collected the clinical data of patients, including general information, imaging parameters, and clinical score, from our hospital's electronic database. Based on the postoperative leg numbness visual analog scale (LN-VAS), the clinical data were divided into the leg numbness group (≥25) and the improvement group (<25). All parameters were included in the least absolute shrinkage and selection operator (LASSO) regression analysis, while the parameters with the area under the curve (AUC) greater than 0.7 were selected to construct nomograms. Furthermore, the accuracy and validity of the model were evaluated using the C-index, decision curve analysis (DCA), calibration curve, and receiver operating characteristic curve (ROC).

Results

A total of 73 patients' clinical data were included in the training set, where 51 patients were assigned to the improvement group and 22 to the leg numbness group. The nomogram was constructed using four selected parameters, including symptom duration, lumbar spinal stenosis (LSS), pelvic incidence (PI), and preoperative low back pain visual analog scale (LBP-VAS). The nomogram predictions were found to range between 0.01 and 0.99. The values of the C-index, AUC, and internally validated C-index were 0.96, 0.96, and 0.94, respectively. Our result showed that the clinical net benefit of the nomogram ranged between 0.01 and 0.99.

Conclusion

Our clinical prediction model demonstrated high predictive ability and clinical validity. Moreover, we found that symptom duration, LSS, PI, and preoperative LBP-VAS were the predictive risk factors for leg numbness after spinal endoscopic surgery.

Development and validation of machine learning-based predictive model for clinical outcome of decompression surgery for lumbar spinal canal stenosis

BACKGROUND CONTEXT

Although the results of decompression surgery for lumbar spinal canal stenosis (LSS) are favorable, it is still difficult to predict the postoperative health-related quality of life of patients before surgery.

PURPOSE

The purpose of this study was to develop and validate a machine learning model to predict the postoperative outcome of decompression surgery for patients with LSS.

STUDY DESIGN/SETTING

A multicentered retrospective study.

PATIENT SAMPLE

A total of 848 patients who underwent decompression surgery for LSS at an academic hospital, tertiary center, and private hospital were included (age 71±9 years, 68% male, 91% LSS, level treated 1.8±0.8, operation time 69±37 minutes, blood loss 48±113 mL, and length of hospital stay 12±5 days).

OUTCOME MEASURES

Baseline and 2 years postoperative health-related quality of life.

METHODS

The subjects were randomly assigned in a 7:3 ratio to a model building cohort and a testing cohort to test the models' accuracy. Twelve predictive algorithms using 68 preoperative factors were used to predict each domain of the Japanese Orthopedic Association Back Pain Evaluation Questionnaire and visual analog scale scores at 2 years postoperatively. The final predictive values were generated using an ensemble of the top five algorithms in prediction accuracy.

RESULTS

The correlation coefficients of the top algorithms for each domain established using the preoperative factors were excellent (correlation coefficient: 0.95-0.97 [relative error: 0.06-0.14]). The performance evaluation of each Japanese Orthopedic Association Back Pain Evaluation Questionnaire domain and visual analog scale score by the ensemble of the top five algorithms in the testing cohort was favorable (mean absolute error [MAE] 8.9-17.4, median difference [MD] 8.1-15.6/100 points), with the highest accuracy for mental status (MAE 8.9, MD 8.1) and the lowest for buttock and leg numbness (MAE 1.7, MD 1.6/10 points). A strong linear correlation was observed between the predicted and measured values (linear correlation 0.82-0.89), while 4% to 6% of the subjects had predicted values of greater than±3 standard deviations of the MAE.

CONCLUSIONS

We successfully developed a machine learning model to predict the postoperative outcomes of decompression surgery for patients with LSS using patient data from three different institutions in three different settings. Thorough analyses for the subjects with deviations from the actual measured values may further improve the predictive probability of this model.

Impact of leg numbness on patient satisfaction following decompression surgery for lumbar spinal stenosis

Decompression surgery is the most common surgical treatment for lumbar spinal stenosis (LSS). Relatively low satisfaction rate was reported. Patients often complaint of residual numbness despite significant pain relief. We hypothesized that numbness had a significant impact on patient satisfaction, but had not been evaluated, which is associated with low satisfaction rate. This study aimed to examine how much numbness is associated with patient satisfaction. We retrospectively reviewed prospectively collected data from consecutive patients who underwent decompression without fusion for LSS. We evaluated the Numeric Rating Scale (NRS) scores of low back pain (LBP), leg pain, and leg numbness preoperatively and at the final follow-up visit. Improvement was evaluated using minimum clinically important differences (MCIDs). Patient satisfaction was evaluated using the question, "How satisfied are you with the overall result of your back operation?". There are four possible answers consisting of "very satisfied (4-point)", "somewhat satisfied (3-point)", "somewhat dissatisfied (2-point)", or "very dissatisfied (1-point)". Spearman correlation was used to evaluate the association between patient satisfaction and reaching MCIDs. A total of 116 patients were included. All three components had correlation with patient satisfaction with the correlation efficient of 0.30 in LBP, 0.22 in leg pain, and 0.33 in numbness. Numbness had greatest correlation efficient value. We showed that numbness has a greater impact than leg/back pain on patient satisfaction in patients undergoing decompression for LSS. We suggest not only LBP and leg pain but also numbness should be evaluated pre- and postoperatively.

Percutaneous spinal endoscopy with unilateral interlaminar approach to perform bilateral decompression for central lumbar spinal stenosis: radiographic and clinical assessment

Background

Recently, a percutaneous spinal endoscopy unilateral posterior interlaminar approach to perform bilateral decompression has been proposed for use in treatment of lumbar spinal stenosis, As a development and supplement to traditional surgery, its advantages regarding therapeutic effects and prognosis, such as minor soft tissue damage, little intraoperative blood loss, and a quick return to daily life. However, there are few analyses of this surgery with a follow-up of more than 1 year,we conducted this study in order to quantitatively investigate radiographic and clinical efficacies of this surgery for central lumbar spinal stenosis.

Materials and methods

Forty-six patients with central lumbar spinal stenosis were enrolled from January 2017 to July 2018. The visual analog scale (VAS) for back pain and leg pain, Oswestry disability index (ODI), modified MacNab criteria were used to evaluate clinical efficiency at preoperative and postoperative time points. The intervertebral height index (IHI), cross-sectional area of the spinal canal (CSAC), calibrated disc signal (CDS) and spinal stability were examined to assess radiographic decompression efficiency via magnetic resonance imaging and X-ray at preoperative and postoperative time points.

Results

The VAS score for lower back pain and leg pain improved from 7.50 ± 0.78 to 1.70 ± 0.66 and from 7.30 ± 0.79 to 1.74 ± 0.68, respectively, and the ODI improved from 72.35 ± 8.15 to 16.15 ± 4.51. In terms of modified MacNab criteria, 91.3% of the patients achieved good or excellent outcomes. Furthermore, significant changes after surgery were observed for the percentage of CSAC, increasing from 125.3 ± 53.9 to 201.4 ± 78 mm²; however, no significant differences were observed for the remaining measurement indicators.

Conclusions

The clinical and radiographic efficacies of this surgery for central lumbar spinal stenosis were good in short-term follow-up, and this surgery did not cause meaningful changes in IHI, CDS, and spine stability in short-term follow-up. The effect of long-term follow-up needs further investigation.