The Selection of Open or Percutaneous Endoscopic Lumbar Discectomy According to an Age Cut-off Point: Nationwide Cohort Study

Trends in degenerative lumbar spinal surgery during the early COVID-19 pandemic in Republic of Korea: A national study utilizing the national health insurance database

During the first year of the COVID-19 pandemic, the Republic of Korea (ROK) experienced three epidemic waves in February, August, and November 2020. These waves, combined with the overarching pandemic, significantly influenced trends in spinal surgery. This study aimed to investigate the trends in degenerative lumbar spinal surgery in ROK during the early COVID-19 pandemic, especially in relation to specific epidemic waves. Using the National Health Information Database in ROK, we identified all patients who underwent surgery for degenerative lumbar spinal diseases between January 1, 2019 and December 31, 2020. A joinpoint regression was used to assess temporal trends in spinal surgeries over the first year of the COVID-19 pandemic. The number of surgeries decreased following the first and second epidemic waves (p<0.01 and p = 0.34, respectively), but these were offset by compensatory increases later on (p<0.01 and p = 0.05, respectively). However, the third epidemic wave did not lead to a decrease in surgical volume, and the total number of surgeries remained comparable to the period before the pandemic. When compared to the pre-COVID-19 period, average LOH was reduced by 1 day during the COVID-19 period (p<0.01), while mean hospital costs increased significantly from 3,511 to 4,061 USD (p<0.01). Additionally, the transfer rate and the 30-day readmission rate significantly decreased (both p<0.01), while the reoperation rate remained stable (p = 0.36). Despite the impact of epidemic waves on monthly surgery numbers, a subsequent compensatory increase was observed, indicating that surgical care has adapted to the challenges of the pandemic. This adaptability, along with the stable total number of operations, highlights the potential for healthcare systems to continue elective spine surgery during public health crises with strategic resource allocation and patient triage. Policies should ensure that surgeries for degenerative spinal diseases, particularly those not requiring urgent care but crucial for patient quality of life, are not unnecessarily halted.

Screening patients requiring secondary lumbar surgery for degenerative lumbar spine diseases: a nationwide sample cohort study

This study aims to identify healthcare costs indicators predicting secondary surgery for degenerative lumbar spine disease (DLSD), which significantly impacts healthcare budgets. Analyzing data from the National Health Insurance Service-National Sample Cohort (NHIS-NSC) database of Republic of Korea (ROK), the study included 3881 patients who had surgery for lumbar disc herniation (LDH), lumbar spinal stenosis without spondylolisthesis (LSS without SPL), lumbar spinal stenosis with spondylolisthesis (LSS with SPL), and spondylolysis (SP) from 2006 to 2008. Patients were categorized into two groups: those undergoing secondary surgery (S-group) and those not (NS-group). Surgical and interim costs were compared, with S-group having higher secondary surgery costs ($1829.59 vs $1618.40 in NS-group, P = 0.002) and higher interim costs ($30.03; 1.86% of initial surgery costs vs $16.09; 0.99% of initial surgery costs in NS-group, P < 0.0001). The same trend was observed in LDH, LSS without SPL, and LSS with SPL (P < 0.0001). Monitoring interim costs trends post-initial surgery can effectively identify patients requiring secondary surgery.

Nationwide sample data analysis of additional surgery rate after anterior or posterior cervical spinal surgery

Surgical outcomes of degenerative cervical spinal disease are dependent on the selection of surgical techniques. Although a standardized decision cannot be made in an actual clinical setting, continued education is provided to standardize the medical practice among surgeons. Therefore, it is necessary to supervise and regularly update overall surgical outcomes. This study aimed to compare the rate of additional surgery between anterior and posterior surgeries for degenerative cervical spinal disease using the National Health Insurance Service-National Sample Cohort (NHIS-NSC) nationwide patient database. The NHIS-NSC is a population-based cohort with about a million participants. This retrospective cohort study included 741 adult patients (> 18 years) who underwent their first cervical spinal surgery for degenerative cervical spinal disease. The median follow-up period was 7.3 years. An event was defined as the registration of any type of cervical spinal surgery during the follow-up period. Event-free survival analysis was used for outcome analysis, and the following factors were used as covariates for adjustment: location of disease, sex, age, type of insurance, disability, type of hospital, Charles comorbidity Index, and osteoporosis. Anterior cervical surgery was selected for 75.0% of the patients, and posterior cervical surgery for the remaining 25.0%. Cervical radiculopathy due to foraminal stenosis, hard disc, or soft disc was the primary diagnosis in 78.0% of the patients, and central spinal stenosis was the primary diagnosis in 22.0% of them. Additional surgery was performed for 5.0% of the patients after anterior cervical surgery and 6.5% of the patients after posterior cervical surgery (adjusted subhazard ratio, 0.83; 95% confidence interval, 0.40-1.74). The rates of additional surgery were not different between anterior and posterior cervical surgeries. The results would be helpful in evaluating current practice as a whole and adjusting the health insurance policy.

Percutaneous Transforaminal Endoscopic Diskectomy for Lumbar Disk Herniation: Young (Age <60 years) versus Older (Age ≥60 years) Patients

BACKGROUND

 We compare the differences in the efficacy of percutaneous transforaminal endoscopic diskectomy (PTED) between the younger (age <60 years) and older (age ≥60 years) patients with lumbar disk herniation (LDH).

METHODS

 From December 2016 to December 2017, 128 patients with symptomatic LDH underwent PTED and were followed up. Forty-four 60 years old and above, including 19 males and 25 females with an average age of 68.7 (61-82) years, were classified as the elderly age group. Eighty-four patients younger than 60 years were classified as the young age group, which included 48 males and 36 females with an average age of 44.7 (16-58) years. The visual analog scale (VAS) scores, Japanese Orthopaedic Association (JOA) scores, and satisfaction rates of the two groups before and after surgery were compared.

RESULTS

 The operation was completed successfully in both groups. The average follow-up times of the elderly and young age groups were 18.47 ± 2.62 (12-23) and 17.90 ± 3.27 (12-23) months, respectively. One patient in the young age group had recurrence 7 months after surgery, and the symptoms were relieved after PTED was performed again. Two patients with nerve root injury after surgery in the young age group completely recovered after 2 months of conservative treatment. There were no significant surgical complications in the elderly age group. There was no significant difference in postoperative VAS, JOA, and MacNab scores between the two groups. The MacNab scores in the elderly age group were excellent for 28 patients, good for 10 patients, and fair for 6 patients; the satisfaction rate was 86.3%. In the young age group, scores were excellent for 63 patients, good for 14 patients, fair for 5 patients, and poor for 2 patients; the satisfaction rate was 91.7%.

CONCLUSION

 The clinical effectiveness of PTED for treatment of LDH in both elderly and young patients is satisfactory. Age is not a predictor of poor outcomes of PTED.

Early Readmission and Reoperation After Percutaneous Transforaminal Endoscopic Decompression for Degenerative Lumbar Spinal Stenosis: Incidence and Risk Factors

PURPOSE

To identify the incidence rates and risk factors for early readmission and reoperation after percutaneous transforaminal endoscopic decompression (PTED) for degenerative lumbar spinal stenosis (DLSS).

PATIENTS AND METHODS

A total of 1011 DLSS patients who underwent PTED were retrospectively evaluated. Of them, 58 were readmitted, and 31 underwent reoperation. The patients were matched with 174 control patients to perform case-control analyses. The clinical and preoperative imaging data of each patient were recorded. Univariate analyses were performed using independent sample t-tests and Fisher's exact tests. Furthermore, the risk factors for early readmission and reoperation were analyzed using multivariate logistic regression analyses.

RESULTS

The incidence rates of readmission and reoperation within 90 days after PTED were 5.7% and 3.1%, respectively. Age (odds ratio [OR]=1.054, p=0.001), BMI (OR=1.104, p=0.041), a history of lumbar surgery (OR=3.260, p=0.014), and the number of levels with radiological lumbar foraminal stenosis (LFS, OR=2.533, p<0.001) were independent risk factors for early readmission. The number of levels with radiological LFS (OR=5.049, p<0.001), the grade of surgical-level facet joint degeneration (OR=2.010, p=0.023), and a history of lumbar surgery (OR=10.091, p<0.001) were independent risk factors for early reoperation.

CONCLUSION

This study confirmed that aging, a higher BMI, a history of lumbar surgery, and more levels with radiological LFS were associated with a higher risk of early readmission. More levels with radiological LFS, a higher grade of surgical-level facet joint degeneration, and a history of lumbar surgery were predictors of early reoperation. These results are helpful in patient counseling and perioperative evaluation of PTED.

Earlier or heavier spinal loading is more likely to lead to recurrent lumbar disc herniation after percutaneous endoscopic lumbar discectomy

PURPOSE

To evaluate the clinical features of and risk factors for recurrent lumbar disc herniation (rLDH) after percutaneous endoscopic lumbar discectomy (PELD) in our clinical practice.

METHODS

A total of 942 consecutive patients who underwent single-level PELD from January 2013 to August 2019 were included. Patients were divided into the recurrence group and the nonrecurrence group. Patient characteristics, radiographic parameters and surgical variables were compared between the two groups. Univariate analysis and multiple logistic regression analysis were adopted to determine the risk factors for recurrence after PELD.

RESULTS

The prevalence of rLDH was 6.05%. Age, sex, tobacco use, duration of low back pain, body mass index (BMI), occupational lifting, herniated disc type, facet joint degeneration, operation time and time to ambulation were significantly different between the two groups. Univariate analysis showed that age (P < 0.001), sex (P = 0.019), BMI (P = 0.001), current smoking (P < 0.001), occupational lifting (P < 0.001), facet joint degeneration (P = 0.001), operation time (P = 0.002), and time to ambulation (P < 0.001) could be significantly associated with the incidence of rLDH after PELD. Multivariate analysis suggested that an older age (P < 0.001), the male sex (P = 0.017), a high BMI (P < 0.001), heavy work (P = 0.003), grade II facet joint degeneration (P < 0.001) and early ambulation (P < 0.001) were significantly related to rLDH after PELD.

CONCLUSIONS

An older age, the male sex, a higher BMI, heavy work, grade II facet joint degeneration, and early ambulation are independent significant risk factors for rLDH after PELD. Great importance should be attached to these risk factors to prevent rLDH. We suggest that patients control their weight, avoid heavy work, ambulate at an appropriate time, and perform strengthening rehabilitation exercises to reduce the incidence of rLDH.

Better Functional Outcome and Pain Relief in the Far-Lateral-Outside-in Percutaneous Endoscopic Transforaminal Discectomy

Background

Even though percutaneous endoscopic transforaminal discectomy (PETD) has been widely used for the surgical treatment of lumbar herniated disc, there are only a few studies directly comparing the clinical outcomes between microdiscectomy (MD) and PETD. Therefore, further studies are needed in order to compare the clinical outcomes between PETD and MD on a single level more thoroughly.

Methods

We proposed a far-lateral-outside-in technique for PETD to get an entry point without complex planning and facet violation. From September 2017 to September 2019, a total of 155 patients (69 with PETD and 86 with MD) were enrolled for this retrospective study, with the inclusion criteria: single level between L2 and S1, clinical sciatica for at least 6 weeks, and failed attempts with non-surgical treatments. Patients were excluded due to cauda equina syndrome, progressive neurologic deficits, history of lumbar spinal surgery, endplate modic changes, severe disc degeneration and less than 24 months of follow-up.

Results

PETD showed significantly shorter surgery time and less intraoperative blood loss compared to MD. The difference between PETD and MD in VAS back pain (but not VAS leg pain) at follow-up time was significant. The ODI improvement in the follow-up time of 6 months between the 2 groups showed a significant difference (PETD: 31.23±6.59, MD: 39.85±7.81, p < 0.001). MD had a significantly higher chance of postoperative wound infection and poor healing, while PETD was more likely to have recurrence of the herniated disc.

Conclusion

MD has been the gold standard procedure for LDH. However, with the advanced endoscopic technology and surgical technique, PETD has emerged as an alternative method due to higher functional outcome and less wound problems.

Direct medical costs after surgical or nonsurgical treatment for degenerative lumbar spinal disease: A nationwide matched cohort study with a 10-year follow-up

Objective

The demand for treating degenerative lumbar spinal disease has been increasing, leading to increased utilization of medical resources. Thus, we need to understand how the budget of insurance is currently used. The objective of the present study is to overview the utilization of the National Health Insurance Service (NHIS) by providing the direct insured cost between patients receiving surgery and patients receiving nonsurgical treatment for degenerative lumbar disease.

Methods

The NHIS-National Sample Cohort was utilized to select patients with lumbar disc herniation, spinal stenosis, spondylolisthesis or spondylolysis. A matched cohort study design was used to show direct medical costs of surgery (n = 2,698) and nonsurgical (n = 2,698) cohorts. Non-surgical treatment included medication, physiotherapy, injection, and chiropractic. The monthly costs of the surgery cohort and nonsurgical cohort were presented at initial treatment, posttreatment 1, 3, 6, 9, and 12 months and yearly thereafter for 10 years.

Results

The characteristics and matching factors were well-balanced between the matched cohorts. Overall, surgery cohort spent $50.84/patient/month, while the nonsurgical cohort spent $29.34/patient/month (p<0.01). Initially, surgery treatment led to more charge to NHIS ($2,762) than nonsurgical treatment ($180.4) (p<0.01). Compared with the non-surgical cohort, the surgery cohort charged $33/month more for the first 3 months, charged less at 12 months, and charged approximately the same over the course of 10 years.

Conclusion

Surgical treatment initially led to more government reimbursement than nonsurgical treatment, but the charges during follow-up period were not different. The results of the present study should be interpreted in light of the costs of medical services, indirect costs, societal cost, quality of life and societal willingness to pay in each country. The monetary figures are implied to be actual economic costs but those in the reimbursement system instead reflect reimbursement charges from the government.

Adjuvant surgical decision-making system for lumbar intervertebral disc herniation after percutaneous endoscopic lumber discectomy: a retrospective nonlinear multiple logistic regression prediction model based on a large sample

BACKGROUND CONTEXT

Lumbar disc herniation (LDH) is a common condition that can affects an individual' quality of life. In patients for whom conservative treatment is ineffective after 3 months, surgical treatment, such as percutaneous endoscopic lumbar discectomy (PELD), is recommended. Because PELD is minimally invasive and produces thorough nerve root decompression, both surgeons and patients often prefer it to other techniques.

PURPOSE

Surgeons find it challenging to prevent postoperative recurrent LDH (rLDH) when they use PELD. We created and verified a model for evaluating patients' recurrence risk factors before surgery so that surgeons can choose other surgical techniques when necessary.

STUDY DESIGN

Retrospective study.

PATIENT SAMPLE

One thousand eight hundred seven patients who underwent PELD at our hospital between 2012 and 2015 were enrolled.

OUTCOME MEASURE

The main outcome measure was rLDH at any follow-up time point.

METHODS

Data were retrospectively analyzed for 1807 patients who underwent PELD at our hospital at some point between 2012 and 2015; all patients had been monitored for at least 5 years after surgery. They were divided into a recurrence group and a nonrecurrence group. Clinical and radiological risk factors were assessed over time to determine their correlations with recurrence and to exclude less important factors. A nonlinear multivariate logistic regression model was established to predict the recurrence rate before surgery.

RESULTS

A total of 1706 patients were monitored after PELD; data were missing for 101 additional patients. The total recurrence rate was 10.38%, and the most common time from surgery to recurrence was 1 year. Ten risk factors were assessed and included in the analysis. Regarding clinical risk factors, patients with hypertension (p < .001; correlation coefficient R [R] = 0.235; odds ratio [OR] = 4.749), diabetes (p < .001; R = 0.381; OR = 16.797), a history of smoking (p < .001; R = 0.347; OR = 9.012), and a history of performing intense physical labor (p < .001; R = 0.409; OR = 19.592) had a higher recurrence rate. Regarding radiological risk factors, patients with disc degeneration (Pfirrmann grade III) (p < .001; R = 0.228; OR = 4.919), Modic changes (level 2) (p < .001; R = 0.309; OR = 7.934), herniation in the form of extrusion (p < .001; R = 0.365; OR = 12.228), a higher disc height index (DHI) (p < .001; R = 0.336), and a larger segmental range of motion (p < .001; R = 0.243) had a higher recurrence rate. When the lumbar motion angle was negative (p < .001; R = 0.318; OR = 13.680), the recurrence rate was high. The overall accuracy of the final model was 97.6% (1665 of 1706). The recognition rate for non-rLDH cases was 99.0% (1514 of 1529), and the rate for rLDH cases was 85.3% (151 of 177); the AUC was 0.9315. A simple model was used. For those patients with postoperative trauma (p < .001; R = 0.382; OR = 13.680), a comparison model was established, and the corresponding recurrence rate was 23.0% ± 25.0% (0-76%).

CONCLUSIONS

A large cohort of patients underwent long-term monitoring, and 11 risk factors were verified for assessing each patient's risks before surgery to predict the postoperative recurrence of LDH following PELD. The risk of recurrence may be effectively reduced with the use of alternative surgical techniques in high risk cases.

Nomograms for Predicting Recurrent Herniation in PETD with Preoperative Radiological Factors

Purpose

To investigate the preoperative radiological risk factors for recurrent lumbar disc herniation (rLDH) within 1 year after percutaneous endoscopic transforaminal discectomy (PETD).

Patients and Methods

A retrospective case–control study was conducted. Between January 2013 and November 2019, a total of 1210 patients with single-level L4/5 LDH who underwent PETD were enrolled in the present study. In total, 62 rLDH patients were diagnosed and collected based on the clinical and radiological manifestations, and 224 non-rLDH controls were selected from the remaining 1148 patients. Preoperative radiological parameters were collected and measured. An age threshold to distinguish patients into subgroups was established using the Youden index. The relationships between the risk factors and rLDH were evaluated by univariate and multivariate analyses in two subgroups. Predictive models were established based on logistic analysis. The area under the curve (AUC) of receiver operating characteristic (ROC) curves, calibration plots, and decision curve analysis (DCA) were used to assess the predictive models.

Results

In the present study, logistic analysis identified six significant predictors associated with rLDH in the young group: superior endplate concave angle (ECA), sacral slope, Modic changes, sagittal range of motion (sROM), extension intervertebral angle (IVA), and lumbar lordosis. Four significant predictors were identified in the elderly group: disc height index (DHI), retrolisthesis (posterior spondylolisthesis), sROM, and extension IVA. Validation of both models demonstrated excellent model discrimination (AUC= 0.940 and 0.946, respectively). DCA also showed excellent clinical utility and benefits.

Conclusion

The nomograms that we constructed could accurately predict individual patient recurrence risk. Individualized measures should be taken for patients of different ages with the above risk factors, and tailored postoperative surveillance of patients who underwent PETD can be planned.

Application of a targeted and quantificational foraminoplasty device in percutaneous transforaminal endoscopic discectomy for L5-S1 disc herniation: preliminary clinical outcomes

OBJECTIVE

Percutaneous transforaminal endoscopic discectomy (PTED) is minimally invasive and has been widely used to treat patients with lumbar disc herniation (LDH) due to its safety and efficiency. However, due to the unique anatomy of the L5-S1 level, the PTED procedure is often difficult to perform in the region. ZESSYS, a targeted and quantificational foraminoplasty device, may help to overcome these anatomical limitations. In this study, we assessed the efficiency and the short-term effects of PTED with ZESSYS at the L5-S1 level.

METHODS

Between January and August of 2018, fifty-six patients with lumbar disc herniation at the single level of L5-S1 and who underwent percutaneous transforaminal endoscopic discectomy were enrolled in this retrospective cohort study. They were segregated into the transforaminal endoscopic surgical system (TESSYS) group and the ZESSYS group. The puncture time, foraminoplasty time, decompression time, and fluoroscopy time were evaluated for operation efficiency. Clinical outcomes were assessed by the visual analog scale (VAS) score and Oswestry Disability Index (ODI) score. The MacNab criteria were used to evaluate patient subjective satisfaction at 12-month follow-up postoperatively.

RESULTS

The average puncture time (5.29 ± 2.05 min), foraminoplasty time (12.82 ± 2.52 min), and fluoroscopy time (26.29 ± 5.96 s) were all significantly shorter in the ZESSYS group than in the TESSYS group (average puncture time 8.07 ± 3.13 min, p < 0.01; foraminoplasty time, 17.18 ± 2.92 min, p < 0.01; fluoroscopy time, 34.73 ± 6.86 s; p < 0.01). No significant differences were observed between the 2 groups in the decompression time (p = 0.057). The VAS score of low back pain and leg pain, as well as the ODI score, improved at all time points postoperatively compared with preoperative, in both the TESSYS group and the ZESSYS group (P < 0.05). There were no significant differences in the VAS score of low back pain, VAS score of leg pain, and ODI score between the TESSYS group and the ZESSYS group at the same time points (P > 0.05). According to the MacNab criteria, the excellent and good rate at 12-month follow-up postoperatively was 85.7% in the TESSYS group and 89.3% in the ZESSYS group (P > 0.05).

CONCLUSION

The targeted and quantificational foraminoplasty device named ZESSYS was more efficient in the puncture and foraminoplasty procedures, effectively protecting the exiting nerve and minimizing the level of radiation exposure. The device is efficient and safe for PTED in treating lumbar disc herniation at the L5-S1 level.

Clinical Anatomy and Possible Clinical Significance of the Postcentral Branches of Spinal Arteries in the L1-L5 Levels

STUDY DESIGN

This was a dissection-based study of 10 embalmed human cadavers.

OBJECTIVE

The objective of this study was to identify and describe the postcentral branches in the L1-L5 intervertebral foramina (IVF) and to determine their possible clinical significance.

SUMMARY OF BACKGROUND DATA

The lower lumbar segmental arteries have been well studied. However, there are few articles with regard to the postcentral branches in the L1-L5 IVF.

MATERIALS AND METHODS

Eighty L1-L5 IVF from 10 embalmed cadavers were studied with a surgical microscope, and the postcentral branches were identified. The branches, origin, insertion, and spatial orientation of the postcentral branches in the L1-L5 IVF were examined. The diameter of the arteries was measured using a Vernier caliper.

RESULTS

In our study, the occurrence rate of a postcentral branch was 100.00% in the 80 IVFs. The postcentral branch was routinely divided into the following 2 types: type 1, postcentral branch main trunks (65.00%), which branch from the spinal arteries or lumbar arteries and then divide into 2 branches (superior and inferior branches), and type 2, superior and inferior branches, which branch straight from the spinal arteries (35.00%). The initial portion of the postcentral branches traveled around the anterolateral edge of the disk to the dorsum.

CONCLUSIONS

Postcentral branches of spinal arteries are common structures in IVF; there are 2 types of postcentral branches. Thorough understanding of the spinal arteries before percutaneous endoscopic lumbar discectomy may be an important step in reducing intraoperative bleeding and ensuring clear visualization, which may result in significant benefits for patients.

The Long-term Reoperation Rate Following Surgery for Lumbar Stenosis: A Nationwide Sample Cohort Study With a 10-year Follow-up

STUDY DESIGN

Retrospective cohort study of a nationwide sample database.

OBJECTIVE

The objective of the present study was to compare the long-term incidence of reoperation for lumbar spinal stenosis (LSS) after anterior fusion, posterior fusion, and decompression.

SUMMARY OF BACKGROUND DATA

Surgical treatment for LSS can be largely divided into 2 categories: decompression only and decompression with fusion. A previous nationwide study reported that fusion surgery was performed in 10% of patients with LSS, and the 10-year reoperation rate was approximately 17%. However, with the development of surgical techniques and changes in surgical trends, these results should be reassessed.

METHODS

The National Health Insurance Service-National Sample Cohort of the Republic of Korea was utilized to establish a cohort of adult patients (N = 1400) who first underwent surgery for LSS during 2005 to 2007. Patients were followed for 8 to 10 years. Considering death before reoperation as a competing event, reoperation hazards were compared among surgical techniques using a Fine and Gray regression model after adjustment for sex, age, diabetes, osteoporosis, Charlson comorbidity index, severity of disability, type of medical coverage, and type of hospital.

RESULTS

The overall cumulative incidence of reoperation was 6.2% at 2 years, 10.8% at 5 years, and 18.4% at 10 years. The cumulative incidence of reoperation was 20.6%, 12.6%, and 18.6% after anterior fusion, posterior fusion, and decompression, respectively, at 10 years postoperatively (P = 0.44). The first surgical technique did not affect the reoperation type (P = 0.27). Decompression was selected as the surgical technique for reoperation in 83.5% of patients after decompression, in 72.7% of patients after anterior fusion, and in 64.3% of patients after posterior fusion.

CONCLUSION

The initial surgical technique did not affect reoperation during the 10-year follow-up period. Decompression was the most commonly used technique for reoperation.

LEVEL OF EVIDENCE

4.

Learning curve of percutaneous endoscopic interlaminar lumbar discectomy versus open lumbar microdiscectomy at the L5-S1 level

Objective

Many studies on the clinical outcome of full endoscopic spine surgery versus open spine surgery have been published. However, only a few studies have compared the learning curves of percutaneous endoscopic interlaminar lumbar discectomy (PEILD) and open lumbar microdiscectomy (OLM) at the L5–S1 level. This study included patients with disc herniation at the L5–S1 level, who underwent PEILD or OLM performed by a single novice surgeon and compared the learning curves.

Methods

Fifty-six patients who underwent PEILD or OLM at the L5–S1 level and completed a minimum 1-year follow-up were enrolled in the study. The patients were allocated to the PEILD group (n = 27, September 2014 to August 2016) or an OLM group (n = 29, September 2012 to August 2014). The learning curves were retrospectively compared based on operation time and surgical outcomes, including complication, failure, and recurrence rates were retrospectively compared.

Results

Significant intergroup differences were not noted with respect to the baseline characteristics, including age, sex, body mass index, preoperative symptoms, or preoperative radiological findings. The mean operation time was significantly shorter in the PEILD group than in the OLM group (63.89±17.99 min versus 78.03±19.01 min, p = 0.006). Based on the operation time according to the number of cases, the learning curve was more difficult in the PEILD group according to the cumulative analysis (case number cut-off for proficiency was 18 in the PEILD group versus 10 in the OLM group) and linear regression analysis (proportionality constant for decrease in the operation time was -0.922 in the PEILD group versus -1.738 in the OLM group) than that in the OLM group. However, the surgical outcomes, including failure, surgical efficacy based on nerve root decompression, complication, and recurrence rates did not differ between the two groups.

Conclusion

Although the learning curve of PEILD was more difficult than that of OLM, the mean operation time was shorter in the PEILD group than that in the OLM group. Moreover, based on the surgical outcomes, PEILD showed efficacy and safety similar to those of OLM.

Long-Term Effect of Diabetes on Reoperation After Lumbar Spinal Surgery: A Nationwide Population-Based Sample Cohort Study

BACKGROUND

Diabetes mellitus (DM) is associated with poor postoperative outcomes and increased morbidity after surgeries. Some previous studies have addressed the close association between DM and those leading to reoperations, whereas others have rejected this theory. This study aimed to evaluate the long-term effect of DM on lumbar spinal surgery using data from a nationwide sample cohort.

METHODS

A population-based cohort comprised one million people, which is a 2.1% representative sample of the Korean population. The present study included adult patients with lumbar degenerative diseases (e.g., lumbar spinal stenosis and spondylolisthesis), who underwent their first lumbar surgery in 2006. The cumulative incidence function for reoperation was calculated and multivariate analysis was performed to define correlation between reoperation and independent factors.

RESULTS

A total of 2020 patients were enrolled and followed up for 10 years. Nondiabetic patients, patients with DM without complication (DwoC), and patients with DM with complication (DwC) accounted for 79.5%, 9.36%, and 11.14% of all patients, respectively. Reoperation incidence stratified by DM was 12.7% for nondiabetic patients, 22.2% for patients with DwoC, and 20.0% for patients with DwC in 10 years of follow-up. During the same period, death, a competing event of reoperation, occurred in 7.8% of nondiabetic patients, in 13.2% of patients with DwoC, and in 20.9% of patients with DwC.

CONCLUSIONS

DM increased 1.65 times the overall cumulative incidences of reoperation after lumbar spinal surgeries for 10 years of follow-up. The reoperation incidence for DwC may be lower than that for DwoC because of a high incidence of death as a competing event of reoperation.

The Long-term Reoperation Rate Following Surgery for Lumbar Herniated Intervertebral Disc Disease: A Nationwide Sample Cohort Study With a 10-year Follow-up

STUDY DESIGN

A retrospective cohort study of a nationwide sample database.

OBJECTIVE

The objective of the present study was to compare the long-term incidence of reoperation for lumbar herniated intervertebral disc disease (HIVD) after major surgical techniques (open discectomy, OD; laminectomy; percutaneous endoscopic lumbar discectomy, PELD; fusion).

SUMMARY OF BACKGROUND DATA

HIVD is a major spinal affliction; if the disease is intractable, surgery is recommended. Considering both the aging of patients and the chronicity of lumbar degenerative disease, the effect of surgical treatment for the lumbar spine should be durable for as long as possible.

METHODS

The National Health Insurance Service-National Sample Cohort (NHIS-NSC) of Republic of Korea was utilized to establish a cohort of adult patients (N = 1856) who underwent first surgery for lumbar HIVD during 2005 to 2007. Patients were followed for 8 to 10 years. Considering death before reoperation as a competing event, reoperation hazards were compared among surgical techniques using the Fine and Gray regression model after adjustment for age, gender, Charlson comorbidity score, osteoporosis, diabetes, the severity of disability, insurance type, and hospital type.

RESULTS

The overall cumulative incidences of reoperation were 4% at 1 year, 6% at 2 years, 8% at 3 years, 11% at 5 years, and 16% at 10 years. The cumulative incidences of reoperation were 16%, 14%, 16%, and 10% after OD, laminectomy, PELD, and fusion, respectively, at 10 years postoperation, with no difference among the surgical techniques. However, the distribution of reoperation types was significantly different according to the first surgical technique (P < 0.01). OD was selected as the reoperation surgical technique in 80% of patients after OD and in 81% of patients after PELD.

CONCLUSION

The probability of reoperation did not differ among OD, laminectomy, PELD, and fusion during the 10-year follow-up period. However, OD was the most commonly used technique in reoperation.

LEVEL OF EVIDENCE

4.

Minimally invasive surgical techniques for the therapy of far lateral disc herniation in middle-aged and elderly patients

To examine the clinical results of different minimally invasive techniques for the therapy of far lateral disc herniation in middle-aged and elderly patients. An endoscopic approach (percutaneous endoscopic lumbar discectomy; PELD), MIS-TLIF combined with contralateral translaminar screw (MIS-TLIF CTS), and MIS-TLIF combined with bilateral pedicle screws (MIS-TLIF BPS) were evaluated via a retrospective chart review. Data from 74 consecutive middle-aged and elderly patients with far lateral disc herniation were analyzed. All patients underwent surgery; 19 with PELD, 24 with MIS-TLIF CTS, and 31 with MIS-TLIF BPS. Clinical data included the length of the incision, duration of the operation, estimated blood loss, hospitalization time, operation cost, recurrence rate, and fusion rate. Preoperative and postoperative patient outcomes including the VAS, ODI scores and MacNab criteria were assessed and recorded. The mean follow-up time was 26.4 months (range from 14 to 46 months). Compared with the internal fixation groups, the length of the incision, duration of operation, estimated blood loss, and hospitalization time were obviously lower in the PELD group. The difference in operation cost among the three methods was statistically significant. The postoperative VAS scores for LBP and LP decreased significantly as compared with those recorded preoperatively. The postoperative ODI scores were lower than those recorded preoperatively. MacNab criteria rating excellent, good and fair results were in 27, 37 and 10 patients, respectively. Conclusion: PELD, MIS-TLIF CTS, and MIS-TLIF BPS are all effective minimally invasive techniques for the therapy of single segment far lateral lumbar disc herniation in middle-aged and elderly patients. PELD had a shorter operation time and less surgical trauma, being a less invasive and more economical method; however, there was no recurrence of disc herniation after fixation. Compared with MIS-TLIF BPS, MIS-TLIF CTS obtained a similar clinical effect and certain costs were saved.

Could the Splitting of the Annulus During Percutaneous Endoscopic Lumbar Diskectomy (PELD) Be a Culprit for Recurrent Disk Herniation?: An Analysis of the Reherniation Pattern After PELD

OBJECTIVE

To explore which preoperative radiologic variables have propensity for reherniation and to evaluate whether the inherent annulus splitting procedure during percutaneous endoscopic lumbar diskectomy (PELD) could prompt reherniation, we assessed the correlation between the anatomic location of annular penetration and reherniation.

METHODS

Three hundred and fifty patients who underwent PELD for central or subarticular disk herniation through a transforaminal approach were followed-up for at least 24 months. Fifty-four subjects that were reoperated for recurrent herniation were allocated as the reherniation group and the other 296 subjects were allocated as the non-reherniation group. The numerical rating scale score, another lumbosacral disk herniation (LDH) lesion in addition to the PELD level (another LDH), location (central or subarticular) and severity of LDH (protrusion or extrusion), and tear of the posterior longitudinal ligament (PLL) were compared between the 2 groups to identify which variables could be predictive factors for reherniation. To assess the influences of PELD on reherniation, location and severity of reherniation were compared with those of initial herniation.

RESULTS

The location at the subarticular region and the existence of a concomitant PLL tear during initial LDH were significantly related to subsequent reherniation. The location and severity of these reherniations were significantly retained when compared with those of primary herniation.

CONCLUSIONS

PLL tear and subarticular herniation were significantly related to recurrent disk herniation. Reherniation patterns after PELD generally matched those of primary herniation. The annulus penetrating step during PELD did not increase the risk of reherniation.

Trends in Incidence and Treatment of Herniated Lumbar Disc in Republic of Korea : A Nationwide Database Study

OBJECTIVE

This study aimed to determine the incidence and analyze trends of the herniated lumbar disc (HLD) based on a national database in the Republic of Korea (ROK) from January 2008 to December 2016.

METHODS

This study was a retrospective analysis of data obtained from the national health-claim database provided by the National Health Insurance Service for 2008-2016 using the International Classification of Diseases. The crude incidence and age-standardized incidence of HLD were calculated, and additional analysis was conducted according to age and sex. Changes in trends in treatment methods and some treatments were analyzed using the Korean Classification of Diseases procedure codes.

RESULTS

The number of patients diagnosed with HLD was 472245 in 2008 and increased to 537577 in 2012; however, it decreased to 478697 in 2016. The pattern of crude incidence and the standardized incidence were also similar. Overall, the incidence of HLD increased annually for the 30s, 40s, 50s, and 70s until 2012 and then decreased. However, the incidence of HLD for the 80s continued to increase. The crude incidence of HLD in female patients exceeded that of male patients in their middle age (30s or 40s) and was 1.5-1.6 times higher than in male patients in their 60s. The total number of open discectomy (OD) increased from 71598 in 2008 to 93942 in 2012 and then decreased to 85846 in 2016. The rate of younger patients (the 20s, 30s, and 40s) who underwent OD was decreased, and the rate of younger patients who underwent percutaneous endoscopic lumbar discectomy was increased. However, the rate of older patients (the 70s and 80s) who underwent OD was continuously increased.

CONCLUSION

This nationwide data on HLD from 2008 to 2016 in the ROK demonstrated that the crude incidence and the standardized incidence increased until 2012 and then decreased. The annual crude incidence was different according to age and sex. These findings may be considered when deciding future health policy, especially in countries with a similar national health insurance system (or with plans to adopt).

Clinical efficacy of percutaneous transforaminal endoscopic discectomy in treating adolescent lumbar disc herniation

Ten years ago, endoscopic techniques began to prevail in clinical treatment of lumbar disc herniation (LDH), but to date, few studies have reported the clinical efficacy of percutaneous transforaminal endoscopic discectomy (PTED) in treating adolescent LDH. This study aimed to evaluate the surgical outcomes of PTED in treating adolescent patients with LDH.Between June 2012 and June 2016, retrospective analysis of 43 adolescent patients diagnosed with single-segment LDH at spine surgery at the Second Affiliated Hospital of Anhui Medical University. The patients' lower limb pain was evaluated using visual analogue scale (VAS) scores and the Oswestry Disability Index (ODI). The VAS is the most commonly-used quantitative method for assessing the degree of pain in clinical practice. The measurement method is to draw a 10 cm horizontal line on a piece of paper, 1 end of which is 0, indicating no pain, while the other end is 10, which means severe pain, and the middle part indicates different degrees of pain. The clinician then asks the patient to make a mark on the line to indicate the degree of pain based on how he or she feels. The ODI is the most widely-used assessment method internationally for lumbar or leg pain at present. The ODI questionnaire is composed of 10 questions, covering pain intensity, independent living, carrying, walking, sitting, standing, sleep, travel, sex, and social life. Every category comprises 6 options, with the highest score for each question being 5 points. Thus the 1st option is worth 0 points, the last option scores 5 points, and higher scores represent more serious dysfunction. Patient satisfaction was evaluated using the modified MacNab score. Clinical outcomes were measured preoperatively, and at 3 days, 6 months, and 12 months postoperatively.All 43 patients were followed up for 12 to 24 months. The average follow-up time was 18.33 months. The VAS scores and ODI scores at 3 days, 6 months, and 12 months postoperatively were significantly lower than before surgery. The difference was statistically significant (P < .001). The differences in VAS scores and ODI scores at 3 days, 6 months, and 12 months after surgery were also statistically significant (P < .001). According to the modified MacNab criteria, 26 cases were rated excellent, 14 cases were good, and 3 cases were acceptable at the final follow-up, and 93.02% of these patients had excellent outcomes.The PTED is an effective and safe surgical method for the treatment of adolescent patients with LDH, but high-quality randomized controlled trials are still required to further verify these findings.

Increased Proportion of Fusion Surgery for Degenerative Lumbar Spondylolisthesis and Changes in Reoperation Rate: A Nationwide Cohort Study With a Minimum 5-Year Follow-up

STUDY DESIGN

A retrospective cohort study.

OBJECTIVE

The objectives of the present study were to examine the changes in the number of surgeries, surgical methods selected, and reoperation rates between the years 2003 and 2008.

SUMMARY OF BACKGROUND DATA

The selection of the appropriate surgical method between decompression-only (D) and decompression plus fusion (DF) represents a challenging clinical dilemma in patients with degenerative lumbar spinal spondylolisthesis. DF is selected in greater than 90% of patients, mostly due to the associated low reoperation rate. However, the outcomes of D have been improved with minimally invasive decompression surgery techniques.

METHODS

The Health Insurance Review and Assessment Service database was used to create cohorts of all Korean patients who underwent surgery for degenerative lumbar spinal spondylolisthesis in 2003 (2003 cohort, n = 5624) and 2008 (2008 cohort, n = 11,706). All patients were followed up for at least 5 years. Reoperation was defined as the occurrence of any type of second lumbar surgery during the follow-up period. The probabilities of reoperation were calculated using the Kaplan-Meier method.

RESULTS

The number of surgeries increased 2.08-fold in 2008. Patients older than 60 years comprised 38.6% of the 2003 cohort and 52.4% of the 2008 cohort. The proportion of DF surgery was 31.13% in the 2003 cohort but 91.54% in the 2008 cohort. However, the high proportion of fusion surgery failed to reduce the reoperation probability in the 2008 cohort (8.1%) compared with that in the 2003 cohort (6.2%). The cost of DF was US$5264 and that of D was $2719 in 2008. DF decreased the reoperation probability by 1% at the cost of $421/patient in the 2008 cohort.

CONCLUSION

The increased proportion of fusion surgery without improvement in reoperation probability in an aging society may be cautiously addressed in deciding future health policies.

LEVEL OF EVIDENCE

4.

Percutaneous transforaminal endoscopic discectomy in the treatment of senior patients with lumbar degenerative disc disease

The aim of the current study was to analyze the efficacy of percutaneous transforaminal endoscopic discectomy (PTED) in the treatment of lumbar degenerative disc disease for senior patients. The clinical and follow-up data of senior patients were retrospectively reviewed. Patients were divided into a PTED group and an open surgery group. Parameters were analyzed, including surgery time, intraoperative fluoroscopy time, intraoperative blood loss, postoperative complications, visual analog scale (VAS) and Japan Orthopedic Association (JOA) scores. Compared with the open surgery group, the surgery time and intraoperative blood loss were decreased, while the intraoperative fluoroscopy time was increased, in the PTED group (P<0.001). Significant improvements in VAS and JOA scores were identified within both groups from preoperative to 12 months following surgery (P<0.001). VAS and JOA scores were significantly improved in the PTEN group compared with the open surgery group at 1 week after surgery (P<0.001), but there was no significant difference between groups prior to and at 12 months following surgery. The incidence of venous thrombosis of the lower extremities in the PTED group was decreased compared with the open surgery group (P<0.05). In the open surgery group, patients suffered from multiple postoperative complications, including constipation, urinary system infection, wound infection, gastrointestinal hemorrhagic stress ulcer, pneumonia, pulmonary embolism, mortality following myocardial infarction, mortality following cerebral infarction, and hemiplegia following cerebral hemorrhage. By contrast, patients in the PTED group did not experience any of these complications. In conclusion, PTED resulted in reduced trauma and a lower incidence of severe complications compared with open surgery, which suggests that PTED is a safe and effective minimally invasive surgery for senior patients with lumbar degenerative disc disease.

Increased Volume of Surgery for Lumbar Spinal Stenosis and Changes in Surgical Methods and Outcomes: A Nationwide Cohort Study with a 5-Year Follow-Up

OBJECTIVE

Examining spine surgery patterns over time is crucial to provide insights into variations and changes in clinical decision making. Changes in the number of surgeries, surgical methods, reoperation rates, and cost-effectiveness were analyzed for all patients who underwent surgery for lumbar spinal stenosis without spondylolisthesis in 2003 (2003 cohort) and 2008 (2008 cohort).

METHODS

The national health insurance database was used to create the 2003 cohort (n = 10,990) and 2008 cohort (n = 27,942). The surgical methods were classified into decompression and fusion surgery. The cumulative reoperation probability between those surgeries was calculated using the Kaplan-Meier method in the 2003 cohort and 2008 cohort. Comparison of the incremental cost-effectiveness ratios showed the additional direct cost of a 1% change in the reoperation probability.

RESULTS

The surgical volume increased 2.54-fold in the 2008 cohort. The age-adjusted number of surgeries per 1 million people increased 2.6-fold (from 154 in the 2003 cohort to 399 in the 2008 cohort) in aged patients and 1.9-fold (from 154 in the 2003 cohort to 291 in the 2008 cohort) in patients 20-59 years old in the 2008 cohort. The proportion of fusion surgeries increased from 20.3% in the 2003 cohort to 37.0% in the 2008 cohort. In total, the 5-year reoperation probabilities increased from 8.1% in the 2003 cohort to 11.2% in the 2008 cohort. Fusion decreased the reoperation probability by 1% at the cost of 1,711 U.S. dollars.

CONCLUSIONS

The increased numbers of spinal surgeries, fusion surgeries, and surgeries in older patients in a recent cohort were noteworthy. However, the increased surgical volume and fusion surgeries did not reduce the reoperation rate.

Increased Volume of Lumbar Surgeries for Herniated Intervertebral Disc Disease and Cost-Effectiveness Analysis: A Nationwide Cohort Study

STUDY DESIGN

Retrospective cohort study of a nationwide database.

OBJECTIVE

The primary objective was to summarize the use of surgical methods for lumbar herniated intervertebral disc disease (HIVD) at two different time periods under the national health insurance system. The secondary objective was to perform a cost-effectiveness analysis by utilizing incremental cost-effectiveness ratio (ICER).

SUMMARY OF BACKGROUND DATA

The selection of surgical method for HIVD may or may not be consistent with cost effectiveness under national health insurance system, but this issue has rarely been analyzed.

METHODS

The data of all patients who underwent surgeries for HIVD in 2003 (n = 17,997) and 2008 (n = 38,264) were retrieved. The surgical methods included open discectomy (OD), fusion surgery, laminectomy, and percutaneous endoscopic lumbar discectomy (PELD). The hospitals were classified as tertiary-referral hospitals (≥300 beds), medium-sized hospitals (30-300 beds), or clinics (<30 beds). ICER showed the difference in the mean total cost per 1% decrease in the reoperation probability among surgical methods. The total cost included the costs of the index surgery and the reoperation.

RESULTS

In 2008, the number of surgeries increased by 2.13-fold. The number of hospitals increased by 34.75% (731 in 2003 and 985 in 2008). The proportion of medium-sized hospitals increased from 62.79% to 70.86%, but the proportion of surgeries performed at those hospitals increased from 61.31% to 85.08%. The probability of reoperation was highest after laminectomy (10.77%), followed by OD (10.50%), PELD (9.20%), and fusion surgery (7.56%). The ICERs indicated that PELD was a cost-effective surgical method. The proportion of OD increased from 71.21% to 84.12%, but that of PELD decreased from 16.68% to 4.57%.

CONCLUSION

The choice of surgical method might not always be consistent with cost-effectiveness strategies, and a high proportion of medium-sized hospitals may be responsible for this change.

LEVEL OF EVIDENCE

4.

Short-term clinical efficacy of percutaneous transforaminal endoscopic discectomy in treating young patients with lumbar disc herniation

Background

In the last decades, full-endoscopic techniques to treat lumbar disc herniation (LDH) have gained popularity in clinical practice. However, few studies have described the safety and efficacy of percutaneous transforaminal endoscopic discectomy (PTED) in treating younger patients with LDH. This study aims to evaluate the preliminary surgical outcome and complication of PTED in treating younger patients with LDH.

Methods

Between June 2012 and June 2016, 72 young patients (< 45 years old) who underwent PTED for single-level LDH were prospectively followed up. All patients were followed up for at least 12 months (range 12–35 months). Pain was measured using visual analogue scale (VAS) scores. Patient satisfaction was evaluated using the MacNab outcome scale. Clinical outcomes were measured preoperatively, at 2 days and 6 months, and 12 months postoperatively.

Results

The mean VAS score for back pain was 5.1 ± 2.3 preoperatively and 3.1 ± 1.2, 2.1 ± 0.5, and 2.0 ± 0.7 at 2 days, 6 months, and 12 months postoperatively, respectively. The VAS score for leg pain was 7.1 ± 2.6 preoperatively and 3.0 ± 1.1, 2.1 ± 1.3, and 1.9 ± 0.8 at 2 days, 6 months, and 12 months postoperatively, respectively. These postoperative scores were all significantly different when compared with preoperative scores (P < 0.001). According to the modified MacNab outcome scale, excellent was obtained in 43 patients, good was obtained in 25 patients, and fair was obtained in 4 patients, and 94.44% of these patients had excellent and good outcomes at the final follow-up. There were no complications related to surgery, and no spinal instability was detected.

Conclusion

PTED appears to be an effective and safe intervention for younger patients with LDH. High-quality randomized controlled trials are required to further study the efficacy and safety of PTED in treating younger patients with LDH.