Survey on Actual Management of Osteoporosis with the Japanese Medical Data Vision Database in Elderly Patients Undergoing Spinal Fusion

Background: No actual data on spinal fusion and management of osteoporosis in Japan have been reported. The aim of the survey was to investigate pre- and post-operative management of osteoporosis, including testing and prescription, in elderly patients undergoing spinal fusion in Japan. Methods: Medical data on patients aged 65 years or older undergoing spinal fusion from April 2018 to March 2022 were extracted from the medical data vision (MDV) database containing health insurance claims data from Japanese acute care hospitals to investigate fusion area, pre- and post-operative osteoporosis tests (bone mineral density and osteoporosis markers), prescriptions of osteoporosis medications, and other information. Results: The analysis set consisted of 26,959 patients. Annual pre-operative BMD testing rates and osteoporosis markers testing rates were higher than the post-operative rates without significant annual changes. The post-operative prescription rate of osteoporosis medications throughout the target period was approximately two times higher than the preoperative rate. The drug with highest pre- and post-operative prescription rates was teriparatide (TPTD) followed by bisphosphonates, showing that the prescription rate of TPTD proportionally increased with the length of fusion area. Conclusions: It was suggested that patients aged 65 years or older undergoing spinal fusion might receive insufficient osteoporosis tests. Despite no trend in the testing rate with the length of fusion area, some tendency was observed in the selection of osteoporosis medications. In patients with osteoporosis undergoing spinal fusion, early examination, diagnosis, and therapeutic intervention may improve the prognoses, and solid testing and prescriptions are therefore expected.

Spinal Anesthesia Reduces Perioperative Polypharmacy and Opioid Burden in Patients Over 65 Who Undergo Transforaminal Lumbar Interbody Fusion

BACKGROUND

Polypharmacy and opioid administration are thought to increase the risk of postoperative cognitive dysfunction and delirium in elderly patients. Spinal anesthesia (SA) holds potential to reduce perioperative polypharmacy in spine surgery. As more geriatric patients undergo spine surgery, understanding how SA can reduce polypharmacy and opioid administration is warranted. We aim to compare the perioperative polypharmacy and dose of administered opioids in patients ≥65 years who undergo transforaminal lumbar interbody fusion (TLIF) under SA versus general anesthesia (GA).

METHODS

A retrospective analysis of 200 patients receiving a single-surgeon TLIF procedure at a single academic center (2014-2021) was performed. Patients underwent the procedure with SA (n = 120) or GA (n = 80). Demographic, procedural, and medication data were extracted from the medical record. Opioid consumption was quantified as morphine milligram equivalents (MME). Statistical analyses included χ2 or Student's t-test.

RESULTS

Patients receiving SA were administered 7.45 medications on average versus 12.7 for GA patients (P < 0.001). Average perioperative opioid consumption was 5.17 MME and 20.2 MME in SA and GA patients, respectively (P < 0.001). The number of patients receiving antiemetics and opioids remained comparable postoperatively, with a mean of 32.2 MME in the GA group versus 27.5 MME in the SA group (P = 0.14). Antiemetics were administered less often as a prophylactic in the SA group (32%) versus 86% in the GA group (P < 0.001).

CONCLUSIONS

SA reduces perioperative polypharmacy in patients ≥65 years undergoing TLIF procedures. Further research is necessary to determine if this reduction correlates to a decrease the incidence of postoperative cognitive dysfunction and delirium.

Clinical and Economic Outcomes of Patients with Osteoporosis Undergoing Spine Fusion Surgery in Japan

Introduction

Spinal fusion surgery with instrumentation is a treatment of choice for many spinal disorders; however, there is little data related to factors associated with early and late outcomes, especially among patients with poor bone quality (e.g., osteoporosis). We conducted this study to characterize the epidemiology and outcomes of patients undergoing spinal fusion surgery with instrumentation in Japan, especially in patients with poor bone quality and those needing additional fixation methods.

Methods

This retrospective observational study used real-world health insurance claims data from the Japanese Medical Data Vision. Adult patients undergoing an index spinal fusion procedure from April 1, 2010, to September 30, 2017, with procedural details, length of stay (LOS), total in-hospital costs, spine-related reoperation, all-cause readmission, and postoperative complications recorded. Data were summarized descriptively overall, by osteoporosis status, and additional fixation method used, and were analyzed in bivariate analyses. Multivariate logistic and linear regressions were used to explore associations between covariates and variables of interest.

Results

A total of 22,932 patients (mean age, 67.3 years; 51.2% male) met the study criteria and were included. A total of 5,288 (23.0%) patients had osteoporosis, and 2,507 (10.9%) needed additional fixation methods; these patients were older, more frequently female, and had higher Elixhauser comorbidity index scores. Osteoporosis and additional fixation use were also associated with longer LOS, higher hospital costs, and higher rates of complications.

Conclusions

Patients with osteoporosis and those needing additional fixation methods have a higher risk for procedural and postoperative complications, reoperation, longer LOS, and higher total hospital costs.

Comparative efficacy of robotic-assisted and freehand techniques for pedicle screw placement in spinal disorders: a meta-analysis and systematic review

The efficacy and safety of robotic-assisted pedicle screw placement compared to traditional fluoroscopy-guided techniques are of great interest in the field of spinal surgery. This systematic review and meta-analysis aimed to compare the outcomes of these two methods in patients with spinal diseases. Following the PRISMA guidelines, we conducted a systematic search across PubMed, Embase, Web of Science, and Cochrane Library. We included randomized controlled trials comparing robotic-assisted and fluoroscopy-guided pedicle screw placement in patients with spinal diseases. Outcome measures included the accuracy of pedicle screw placement, postoperative complication rates, intraoperative radiation exposure time, and duration of surgery. Data were analyzed using Stata software. Our analysis included 12 studies. It revealed significantly higher accuracy in pedicle screw placement with robotic assistance (odds ratio [OR] = 2.83, 95% confidence interval [CI] = 2.20-3.64, P < 0.01). Postoperative complication rates, intraoperative radiation exposure time, and duration of surgery were similar between the two techniques (OR = 0.72, 95% CI = 0.31 to 1.68, P = 0.56 for complication rates; weighted mean difference [WMD] = - 0.13, 95% CI = - 0.93 to 0.68, P = 0.86 for radiation exposure time; WMD = 0.30, 95% CI = - 0.06 to 0.66, P = 0.06 for duration of surgery). Robotic-assisted pedicle screw placement offers superior placement accuracy compared to fluoroscopy-guided techniques. Postoperative complication rates, intraoperative radiation exposure time, and duration of surgery were comparable for both methods. Future studies should explore the potential for fewer complications with the robotic-assisted approach as suggested by the lower point estimate.

Utility of desflurane as an anesthetic in motor-evoked potentials in spine surgery and the facilitating effect in tetanic stimulation of bilateral median nerves

Although desflurane is a safe and controllable inhalation anesthetic used in spinal surgery, to our knowledge, there have been no reports of successful motor-evoked potential (MEP) recordings under general anesthesia with desflurane alone. A high desflurane concentration may reduce the risk of intraoperative awareness but can also reduce the success of MEP recording. Therefore, we aimed to evaluate the reliability of MEP monitoring and investigate whether tetanic stimulation can augment MEP amplitude under general anesthesia with high-concentration desflurane during spinal surgery. We prospectively evaluated 46 patients who were scheduled to undergo lumbar surgery at a single center between 2018 and 2020. Anesthesia was maintained with an end-tidal concentration of 4% desflurane and remifentanil. Compound muscle action potentials were recorded bilaterally from the abductor pollicis brevis, abductor hallucis, tibialis anterior, gastrocnemius, and quadriceps. For post-tetanic MEPs (p-MEPs), tetanic stimulation was applied to the median nerves (p-MEPm) and tibial nerves (p-MEPt) separately before transcranial stimulation. The average success rates for conventional MEP (c-MEP), p-MEPm, and p-MEPt were 77.9%, 80%, and 79.3%, respectively. The p-MEPm amplitudes were significantly higher than the c-MEP amplitudes in all muscles (P < 0.05), whereas the p-MEPt amplitudes were not significantly different from the c-MEP amplitudes. The MEP recording success rates for the gastrocnemius and quadriceps were inadequate. However, bilateral median nerve tetanic stimulation can effectively augment MEPs safely under general anesthesia with high-concentration desflurane in patients who undergo spinal surgery.

Morphological description of sagittal lumbar spinal alignment using curve magnitude, span, and apex-the multiethnic alignment normative study (MEANS)

BACKGROUND CONTEXT

Current definition of lumbar lordosis uses the L1-S1 angle. Prevailing classification of sagittal spinal morphology, derived from a young adult population, classifies the spine into four subtypes defined by their sacral slope (SS) and curve morphology.

PURPOSE

To describe physiological sagittal alignment of the lumbar spine across age groups using three main parameters that dictate the lumbar curve: angular magnitude, span, and apex.

STUDY DESIGN

A large, multicenter, cross-sectional radiographic comparison study.

PATIENT SAMPLE

Four hundred sixty-eight healthy, asymptomatic subjects aged 18 to 80 years from five countries (184 males, 284 females; 98 France, 119 Japan, 79 Singapore, 80 Tunisia, 92 USA, mean age 40.61±14.99 years).

OUTCOME MEASURES

Sagittal lumbar profile subtypes clustered based on lumbar curve angular magnitude (ie, Cobb angle of the lumbar lordosis), span, and apex, and described by sagittal radiographic parameters.

METHODS

Subjects underwent whole-body low-dose EOS stereoradiographs. Comparisons between conventional L1-S1 lumbar lordosis (cLL) and true lumbar lordosis (tLL, defined by the inflection-S1 angle) were conducted. Using the K-means clustering algorithm, lumbar curve angular magnitude, span and apex were used to classify sagittal spinal morphology into subtypes, stratified across age groups. Further univariate and multivariate analyses were conducted to compare radiographic parameters across subtypes, and identify predictors for the lumbar curve's angular magnitude, span and apex.

RESULTS

Mean cLL was -57.27±11.37°, and tLL was -62.62±10.76°. Using tLL, instead of cLL, to describe sagittal spinal morphology, we found significant differences in terms of angular magnitude of the lumbar curve, the median thoracolumbar inflection vertebral level and pelvic incidence-lumbar lordosis mismatch Multivariate analysis found a larger SS, more positive T9 tilt, and more kyphotic T4-T12 predictive for a more lordotic tLL, while a larger overhang distance predicted for a less lordotic tLL (p-values<.001). In addition, a larger T9 tilt, less lordotic L1-L5 and smaller PT were predictors of a more caudal thoracolumbar inflection and lumbar apical vertebral levels (p-values<.001). Sagittal lumbar profiles of subjects age<30 years, 30≤age<60 years and age≥60 years, could be classified into 4, 6, and 3 subtypes, respectively.

CONCLUSIONS

Sagittal lumbar profile subtypes vary across age groups, with more homogenous morphologies at the extremes of ages. Improved understanding of the morphological evolution of sagittal spinal profiles with age in asymptomatic individuals will help guide future individualized surgical treatment.

Characteristics of pedicle screw misplacement using freehand technique in degenerative scoliosis surgery

PURPOSE

This study aimed to estimate the accuracy of pedicle screw (PS) placement in degenerative scoliosis surgery, characterize a patient population with PS misplacement, and analyze the association between misplaced PS vector and lumbar coronal curve.

METHODS

In this study, 122 patients (average age 68.6 years), who underwent corrective and decompression surgery, were selected retrospectively. PS accuracy was evaluated in the thoracic to lumbar spine. We identified characteristics of misplacement in each patient. Screw positions were categorized into grade A, entirely in the pedicle; grade B, < 2 mm breach; grade C, 2-4 mm breach; and grade D, > 4 mm breach using postoperative computed tomography.

RESULTS

The mean preoperative lumbar coronal curve was 32.3 ± 18.4°, and the number of fused vertebrae was 8.9 ± 2.8. A total of 2032 PS were categorized as follows: grade A, 1897 PS (93.3%); grade B, 67 (3.3%); grade C, 26 (1.3%); and grade D, 43 (2.1%). One PS (grade D), inserted at T5, needed surgery for removal due to neurological deficit. The misplacement group (grades C and D) had a significantly stronger lumbar coronal curve and apical vertebral rotation than the accuracy group (grades A and B). Misplaced PS vector (direction and degree) was significantly correlated with inserted vertebral rotation. Grade D misplacement was distributed mainly around the transitional vertebra of the lumbar curve.

CONCLUSIONS

The accuracy of PS insertion in the thoracic to lumbar spine was high in DS surgery, but the need for care was highlighted in the transitional vertebra.

Tibial nerve SEPs in diagnosing lumbar spinal stenosis: The utility of segmental evaluation using P15 and N21

Objective

To establish the utility of the additional evaluation of the P15 potential generated at the greater sciatic foramen in the tibial nerve somatosensory evoked potentials (SEPs) in diagnosing lumbar spinal stenosis (LSS).

Methods

We retrospectively reviewed tibial nerve SEP findings in patients having MRI-confirmed LSS at the cauda equina or conus/epiconus region. P15 and N21 potentials were recorded and the following findings were defined as localizing abnormalities: 1) normal P15 latency either with prolonged P15-N21 interval or with absent N21; 2) decreased ratio of the N21 amplitude to P15 amplitude. As non-localizing abnormalities, N21 and P38 latencies were also evaluated. Tibial nerve F-wave findings were also investigated.

Results

According to the entry criteria, 18 patients were included, 15 with cauda equina lesions and 3 with conus/epiconus lesions. Localizing abnormalities in SEPs were found in 67% of patients, achieving significantly higher sensitivity than delayed P38 latency (28%), and higher sensitivity than N21 abnormalities (39%), though this was not significant. Localizing abnormalities were observed even in 6 out of 11 patients lacking both sensory symptoms and signs. Tibial nerve F-wave was abnormal in 36% of 14 patients with F-wave examinations, whereas the localizing abnormalities in SEPs were found in 64% of the same patient population. P15 amplitude was depressed in 4 patients (22%), which may indicate the involvement of the dorsal root ganglion in LSS, although its latency was normal even for these patients.

Conclusions

Tibial nerve SEPs with the recording of P15 and N21 potentials achieved sufficiently high sensitivity in diagnosing LSS. They have the advantage over F-wave in that they can localize the lesion at the cauda equina or conus/epiconus level.

Significance

Tibial nerve SEPs are promising in evaluating LSS, especially in documenting sensory tract involvement in cases lacking sensory symptoms/signs.

Acupuncture for postoperative pain of lumbar disc herniation: A systematic review and meta-analysis

BACKGROUND

Evidence for the effects of acupuncture on postoperative pain of Lumbar disc herniation (LDH) is inconsistent. We conducted this systematic review and meta-analysis to evaluate the efficacy of acupuncture for postoperative pain of LDH.

METHODS

We performed a comprehensive search on PubMed, Embase, Web of Science, Cochrane Central, and four Chinese databases (CNKI, Wan Fang, CBMdisc, and VIP) for articles published before September 2021. The data extraction table was made for the ten included studies, and the risk of bias was assessed using the Cochrane collaboration tool, followed by statistical analysis using RevMan 5.3.

RESULTS

A total of ten studies involving 838patients were included. The statistical meta-analysis showed that acupuncture treatment was significantly better than drugs in improving cure rate (OR = 2.24, 95% CI = [1.58, 3.19], P < .00001) and the total effectiveness rate (OR = 4.85, 95% CI = [2.59, 9.08], P < .00001). And the results from the meta-analysis showed that acupuncture group was superior to control group in debasing visual analog scale score (MD = -1.26, 95% CI = [-1.72, -0.79], P < .00001) and improving Japanese Orthopaedic Association score (MD = 4.21, 95% CI = [1.53, 6.90], P < .00001). In addition, acupuncture was statistically significantly better than drugs (OR = 0.27, 95% CI = [0.11, 0.62], P = .002) in the incidence of adverse events, However, there was no statistically significant difference between acupuncture and rehabilitation (OR = 0.36, 95% CI = [0.07, 1.98], P = .24).

CONCLUSION

Acupuncture is an effective and safe treatment for postoperative pain of LDH. It can be recommended to manage patients with postoperative pain of LDH. However, considering the unsatisfactory quality of the included studies, more high-quality randomized controlled trials with a large sample size are needed to elucidate this issue.

Development of a Novel Diagnostic Support Tool for Degenerative Cervical Myelopathy Combining 10-s Grip and Release Test and Grip Strength: A Pilot Study

Early diagnosis of degenerative cervical myelopathy (DCM) is desirable, as delayed treatment can cause irreversible spinal cord injury and subsequent activity of daily living (ADL) impairment. We attempted to develop a straightforward and accurate diagnostic tool for DCM by combining the grip and release test (GRT) and grip strength. As a pilot study, we measured the GRT and grip strength of patients with DCM (n = 247) and a control group (n = 721). Receiver operating characteristic analysis was performed using the lower left and right. The Youden index was used to set cutoff values by sex and age group. The diagnostic performance of each test varied by sex and age, and a diagnostic support tool was created to determine any abnormal results in a test. The calculated M/F cutoff values for GRT were as follows: 40–59 years, 21/18; 60–69 years, 17/17; 70–79 years, 15/15; and 80–89 years, 11/12. The calculated M/F cutoff values for grip strength 32/20, 29/13, 21/15, and 19/10. When either GRT or grip strength was judged as positive, the overall sensitivity was 88.2%, specificity was 78.1%, positive likelihood ratio was 4.03, and the negative likelihood ratio was 0.15. This novel diagnostic support tool was superior to using GRT and grip strength alone in the early DCM diagnosis. Future research to obtain age- and sex-specific data is necessary to validate and further improve the tool.

Neurogenic lower urinary tract dysfunction in association with severity of degenerative spinal diseases: Short-term outcomes of decompression surgery

OBJECTIVES

Cervical myelopathy (CM) and lumbar canal stenosis (LCS) are common degenerative spinal diseases among the elderly, and the major associated complaints include lower urinary tract symptoms (LUTS). The aim of this study was to investigate subjective and objective urological parameters of patients undergoing decompression surgery for CM and LCS.

METHODS

We retrospectively reviewed patients who underwent evaluation by the International Prostate Symptom Score (IPSS) and uroflowmetry before decompression surgery for CM and LCS. Patients with comorbidities that can affect LUTS were excluded. Postoperative changes were evaluated in patients followed up within 1 month.

RESULTS

Among referrals to urological consultations for LUTS, 231 patients were evaluated preoperatively. Moderate-severe urinary symptoms (IPSS ≥ 8) were present in 59.8% of 92 CM patients and 64.0% of 139 LCS patients. Poor voiding patterns defined as maximum urinary flow rate <12 mL/s or postvoid residual volume >100 mL were identified in 26.1% of CM and 25.2% of LCS. While IPSS did not associate with disease severity, poor voiders presented with worse Japanese Orthopedic Association scores. Moreover, poor voiders suffered for a longer period of time from orthopedic symptoms due to LCS. In followed-up patients (CM, n = 32; LCS, n = 47), total IPSS, storage subscores, and voiding subscores were significantly improved after surgery, as was voiding time from uroflowmetry.

CONCLUSIONS

This study demonstrated high prevalence of lower urinary tract dysfunction of CM and LCS as well as short-term effectiveness of decompression surgery. These results would encourage urologists to consider an orthopedic consultation when lower urinary tract dysfunction is identified in patients with degenerative spinal diseases.

Efficacy of Nerve Root Block for the Treatment of Lumbar Spinal Canal Stenosis in Adults Older Than 80 Years of Age

Background: Patients with advanced lumbar spinal canal stenosis (LCS) often prefer non-operative treatment owing to decreased physiological function and comorbidities. Although the therapeutic value of selective nerve root block (SNRB) for LCS is confirmed, there are few reports of its effectiveness in the elderly. We investigated the efficacy of SNRB for LCS in patients over 80 years of age.

Methods: The subjects were 112 patients aged over 80 years (mean age: 84 years; 45 men and 67 women ) with medication-resistant LCS without cauda equina syndrome who underwent SNRB. Cases with acute-onset lumbar disc herniation were excluded. We retrospectively investigated and compared the presence or absence of surgery, effect of SNRB, number of procedures, duration of disease, and magnetic resonance imaging findings. Patients who could avoid the surgery by SNRB were defined as the effective group. Patients whose symptoms were not relieved by SNRB and who underwent surgery and those whose symptoms were not relieved but who continued conservative treatment were defined as the ineffective group. A total of one to seven SNRBs were performed in both groups, and the same spine surgeon performed the entire procedure from SNRB to surgery.

Results: There were 86 nonoperative patients (69 effective cases) and 26 operative patients; the overall rate of effectiveness was 61% (69/112 patients). The area of the spinal canal at the responsible level was 108.63 mm² in the effective group compared with 77.06 mm² in the ineffective group. This was significantly narrower in the ineffective group (p=0.0094). There was no significant difference in the duration of illness, number of blocks, or hernia complication rate between the groups. No patient experienced severe neuralgia that may have been caused by neuropathy during SNRB.

Discussion: Our outcome showed that more than 60% of older patients with LCS showed symptomatic improvement with SNRB. SNRB can be performed relatively safely in the elderly and appears to be a favorable treatment option for older patients with various risks, such as poor general condition.

Conclusions: Multiple sessions of SNRB may provide older patients with symptomatic improvement and may be an option for treatment.

Return to golf after adult degenerative and deformity spine surgery: a preliminary case series of how surgery impacts golf play and performance

Background

Golf is a commonly played sport among older adults, and degenerative and/or deformity spine pathology can severely impact older individuals' ability to play golf. In a cohort of self-identified, avid golfers undergoing degenerative or deformity spine surgery, we report their: (I) presentation, (II) operative treatment, and (III) return-to-play (RTP) process.

Methods

A retrospective case series of self-identified, avid golfers undergoing spine surgery at a single institution from 2015-2019 was undertaken. Demographic, presenting, operative, RTP data, along with numerical rating scale (NRS) pain scores were collected. The first and full RTP time postoperatively, in addition to the following golf metrics: 18-hole rounds per month, handicap, and self-perceived effort/performance were obtained.

Results

A total of 6 golfers were included, 3 undergoing each degenerative and deformity operations. Mean age was 60 years, and 5 of 6 (83%) patients were female. All patients were self-identified, avid golfers with a mean experience of 31 years. Mean preoperative NRS back/neck pain was 9.7, which decreased to 0.8 postoperatively (P<0.001). Players undergoing smaller operations (lumbar fusion/cervical laminoplasty) returned to golf sooner than patients undergoing larger deformity corrections, with a mean first RTP of 4.3 months for degenerative patients vs. 9.7 months among deformity patients. All patients played either the same or more rounds of golf after surgery once they reached full RTP. The handicap of all players improved after surgery to better than before surgery, except for one high-level golfer with a handicap of 9 preoperatively that went to 15 postoperatively following an extensive revision deformity reconstruction.

Conclusions

All patients returned to playing golf at or more frequently than their preoperative status. Degenerative patients returned to play sooner than deformity patients. All patients performed at a higher level after surgery, except for one high-level golfer whose handicap worsened slightly. These data provide baseline information for future prospective studies of golfers undergoing spine surgery.

Outcomes of lumbar spinal fusion in super-elderly patients aged 80 years and over: Comparison with patients aged 65 years and over, and under 80 years

Despite the increasing prevalence of spinal surgery in super-elderly (SE) patients, the outcomes and complication rates have not been fully elucidated. The purpose of this study was to compare the outcomes and complications of lumbar spinal fusion for degenerative lumbar spinal stenosis (DLSS) in SE patients aged 80 years and over with those in patients aged 65 years and over, and under 80 years.This study analyzed 160 patients who underwent spinal fusion for DLSS between January 2011 and November 2019. Thirty patients in the SE group (group SE, ≥80 years) and 130 patients in the elderly group (group E, ≥65 years and <80 years) were enrolled. The performance status was evaluated by preoperative American society of anesthesiologists (ASA) score. Visual analog scales for back pain (VAS-BP) and leg pain (VAS-LP), and Korean Oswestry disability index (K-ODI) were used to assess clinical outcomes preoperatively and 1 year postoperatively. Percent changes of VAS-BP, VAS-LP and K-ODI were also analyzed. Fusion rates were evaluated by computed tomography 6 months and 1 year postoperatively. Furthermore, bone mineral density, operative time, estimated blood loss, blood transfusion, hospital days, hospitalization in intensive care unit and postoperative complications were compared.The average age of group SE was 82.0 years and that of group E was 71.6 years. There were no differences in preoperative ASA score, preoperative or postoperative VAS BP and VAS-LP, bone mineral density, operative time, estimated blood loss, blood transfusion, hospital days, hospitalization in intensive care unit and fusion rates between the groups. Preoperative and postoperative K-ODI were higher in group SE than group E (all P < .05). However, percent changes of VAS-BP, VAS-LP and K-ODI showed no significant differences. Overall early and late complications were not significantly different between the groups; however postoperative delirium was more common in group SE than group E (P = .027). SE status was the only risk factor for postoperative delirium with odds ratio of 3.4 (P = .018).Spinal fusion surgery is considerable treatment to improve the quality of life of SE patients with DLSS, however careful perioperative management is needed to prevent postoperative delirium.

The Effect of Patient Position on Psoas Morphology and in Lumbar Lordosis

INTRODUCTION

Among the interbody fusions, lateral lumbar interbody fusion allows access to the lumbar spine through the major psoas muscle, which offers several advantages to the spine surgeon. However, some of its drawbacks cause surgeons to avoid using it as a daily practice. Therefore, to address some of these challenges, we propose the prone transpsoas technique, differing mainly from the traditional technique on patient position-moving from lateral to prone decubitus, theoretically enhancing the lordosis and impacting the psoas morphology.

METHODS

Twenty-four consecutive patients were invited to have magnetic resonance imaging examinations in 3 different positions (prone, dorsal, lateral). Two observers measured the following parameters: vertebral body size, psoas diameter, psoas anterior border distance, plexus distance, total lumbar lordosis, distal lumbar lordosis, and proximal lumbar lordosis. Values of P < 0.05 were deemed significant.

RESULTS

The prone position yielded a significant increase in the lumbar lordosis, both in L1-S1 (57° vs. 46.5°) and proximal lordosis (40.4° vs. 36.9°) compared with the lateral position. Regarding the morphologic aspects, patients in the prone position presented lesser psoas muscles forward shift, but no difference was noted in the plexus position neither for L3-L4 nor L4-L5.

CONCLUSIONS

The prone position resulted in a significantly increased lumbar lordosis, both distal and proximal, which may enable the spine surgeon to achieve significant sagittal restoration just by positioning. The prone position also produced a posterior retraction of the psoas muscle. However, it did not significantly affect the position of the plexus concerning the vertebral body.

Predictors for quality of life improvement after surgery for degenerative cervical myelopathy: a prospective multi-center study

BACKGROUND

Degenerative cervical myelopathy (DCM) can significantly impair a patient's quality of life (QOL). In this study, we aimed to identify predictors associated with QOL improvement after surgery for DCM.

METHODS

This study included 148 patients who underwent surgery for DCM. The European QOL-5 Dimension (EQ-5D) score, the Japanese Orthopedic Association for the assessment of cervical myelopathy (C-JOA) score, and the Nurick grade were used as outcome measures. Radiographic examinations were performed at enrollment. The associations of baseline variables with changes in EQ-5D scores from preoperative to 1-year postoperative assessment were investigated using a multivariable linear regression model.

RESULTS

The EQ-5D and C-JOA scores and the Nurick grade improved after surgery (P < 0.001, P < 0.001, and P < 0.001, respectively). Univariable analysis revealed that preoperative EQ-5D and C-JOA scores were significantly associated with increased EQ-5D scores from preoperative assessment to 1 year after surgery (P < 0.0001 and P = 0.045). Multivariable regression analysis showed that the independent preoperative predictors of change in QOL were lumbar lordosis (LL), sacral slope (SS), and T1 pelvic angle (TPA). According to the prediction model, the increased EQ-5D score from preoperatively to 1 year after surgery = 0.308 - 0.493 × EQ-5D + 0.006 × LL - 0.008 × SS + 0.004 × TPA.

CONCLUSIONS

Preoperative LL, SS, and TPA significantly impacted the QOL of patients who underwent surgery for DCM. Less improvement in QOL after surgery was achieved in patients with smaller LL and TPA and larger SS values. Patients with these risk factors may therefore require additional support to experience adequate improvement in QOL.

Lumbar disc herniation surgery: Is it worth adding interspinous spacer or instrumented fusion with regard to disc excision alone?

BACKGROUND

Discectomy is sometimes associated with recurrence of disc herniation and pain after surgery. The evidence to use an interspinous dynamic stabilization system or instrumented fusion in association with disc excision to prevent pain and re-operation remains controversial. In this study, we analyzed if adding interspinous spacer or fusion, offers advantages in relation to microdiscetomy alone.

METHODS

Patients with lumbar disc herniation were divided in 3 groups; microdiscectomy alone (MD), microdiscectomy plus interspinous spacer (IS) and open discectomy plus posterior lumbar interbody fusion (PLIF). The clinical efficacy was measured using the Owestry Disability Index (ODI). Other outcome parameters including visual analogue scale for pain (VAS) back and legs, length of stay, direct in-hospital cost, 90-day complication rate, and 1-year re-operation rate were also evaluated.

RESULTS

A total of 103 patients whose mean age was 39.1 (±8.5) years were included. A significant improvement of the ODI and VAS back and legs pain baseline score was detected in the 3 groups. After 1 year, no significant differences in ODI, VAS back and legs pain were found between the 3 groups. There was an increase of 169% of the total direct in- hospital cost in IS group and 287% in PLIF group, in relation to MD (p < 0.001). Length of stay was 86% higher in the IS group and 384% longer in the PLIF group compared to MD (p < 0.001). The 1 year re-operation rates were 5.6%, 10% and 16.2% (p = 0.33). Discectomy seems to be the main responsible for the clinical improvement, without the interspinous spacer or fusion adding any benefit. The addition of interspinous spacer or fusion increased direct in-hospital cost, length of stay, and did not protect against re-operation.

Impact of Obesity on Complication Rates, Clinical Outcomes, and Quality of Life after Minimally Invasive Transforaminal Lumbar Interbody Fusion

BACKGROUND

 Percutaneous pedicle screw fixation in obese patients remains a surgical challenge. We aimed to compare patient-reported outcomes and complication rates between obese and nonobese patients who were treated by minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF).

METHODS

 The authors retrospectively reviewed patients who underwent MIS-TLIF at a single institution between 2011 and 2014. Patients were classified as obese (body mass index [BMI] ≥30 kg/m²) or nonobese (BMI < 30 kg/m²), according to their BMI. Outcomes assessed were complications, numerical rating scale (NRS) scores for back and leg pain, Oswestry Disability Index (ODI), and 36-Item Short-Form Survey (SF-36) scores.

RESULTS

 The final study group consisted of 71 patients, 24 obese (33.8%, 34.8 ± 3.8 kg/m²) and 47 nonobese (66.2%, 25.4 ± 2.9 kg/m²). Instrumentation failures (13.6 vs. 17.0%), dural tears (17.2 vs. 4.0%), and revision rates (16.7 vs. 19.1%) were similar between both groups (p > 0.05). Perioperative improvements in back pain (4.3 vs. 5.4, p = 0.07), leg pain (3.8 vs. 4.2, p = 0.6), and ODI (13.3 vs. 22.5, p = 0.5) were comparable among the groups and persisted at long-term follow-up. Obese patients had worse postoperative physical component SF-36 scores than nonobese patients (36.4 vs. 42.7, p = 0.03), while the mental component scores were not statistically different (p = 0.09).

CONCLUSION

 Obese patients can achieve similar improvement of the pain intensity and functional status even at long-term follow-up. In patients with appropriate surgical indications, obesity should not be considered a contraindication for MIS-TLIF surgery.

Anterior Decompression and Fusion Versus Laminoplasty for Cervical Myelopathy Caused by Soft Disk Herniation: A Long-term Prospective Multicenter Study

STUDY DESIGN

A prospective multicenter study.

OBJECTIVE

The purpose of this study was to determine whether laminoplasty (LP) is comparable for myelopathy caused by cervical disk herniation (CDH).

SUMMARY OF BACKGROUND DATA

Anterior decompression and fusion (ADF) has conventionally been used for myelopathy caused by CDH with stable outcomes. However, recurrence of myelopathy due to adjacent segment degeneration are its drawbacks. The efficacy of LP without discectomy has been sporadically reported, but no long-term prospective study has been conducted to verify it.

MATERIALS AND METHODS

Patients with cervical myelopathy caused by CDH were studied. The first 30 patients and the next 30 patients were treated with ADF and LP, respectively. The outcomes were compared between the 22 ADF patients and the 20 LP patients who had completed the follow-up examination scheduled 10 years after surgery.

RESULTS

There was no statistically significant difference in the postoperative severity or recovery rate of myelopathy between the 2 groups 10 years after surgery. One patient in the ADF group underwent LP for secondary myelopathy due to adjacent segment degeneration 2 years after the surgery. Reoperation was not required for patients in the LP group. Postoperative neck pain was significantly more severe in the LP group than in the ADF group.

CONCLUSIONS

ADF and LP for cervical myelopathy caused by CDH achieve similarly favorable outcomes. Recurrence of myelopathy caused by adjacent segment degeneration is a disadvantage of ADF while residual neck pain is a disadvantage of LP.

Unilateral Laminectomy by Endoscopy in Central Lumbar Canal Spinal Stenosis: Technical Note and Early Outcomes

STUDY DESIGN

Retrospective study.

OBJECTIVE

To evaluate the outcomes and safety of endoscopic laminectomy for central lumbar canal spinal stenosis.

SUMMARY OF BACKGROUND DATA

.: Spinal endoscopy is mostly used in the treatment of lumbar disc herniation, while endoscopic laminectomy for lumbar spinal stenosis is rarely reported.

METHODS

From January 2016 to June 2017, 38 patients with central lumbar canal spinal stenosis were treated with endoscopic laminectomy. Clinical symptoms were evaluated at 1, 3, 6, and 12 months and the last follow-up after surgery. Functional outcomes were assessed by using the Japanese Orthopedic Association Scores (JOA) and Oswestry Disability Index (ODI). The decompression effect was assessed by using the dural sac cross-sectional area (DSCA). Lumbar stability was evaluated using lumbar range of motion (ROM), ventral intervertebral space height (VH), and dorsal intervertebral space height (DH).

RESULTS

The mean age of the cases was 60.8 years, the mean operation time was 66.3 minutes, the blood loss was 38.8 mL, and the length of incision was 19.6 mm. The mean time in bed was 22.3 hours, and the mean hospital stay was 8.8 days. JOA scores were improved from 10.9 to 24.1 (P < 0.05), ODI scores were improved from 79.0 to 27.9 (P < 0.05), DSCA was improved from 55.7 to 109.5 mm (P < 0.05), ROM scores were improved from 5.6° to 5.7° (P < 0.05), and DH scores were reduced from 6.6 to 6.5 mm (P < 0.05). There was no significant difference in VH before and after operation (P > 0.05). There were no serious complications during the follow-ups.

CONCLUSION

Endoscopic laminectomy had the advantage of a wider view, which was effective, safe, and less invasive for lumbar spinal stenosis.

LEVEL OF EVIDENCE

5.

Clinical efficacy and radiographic K-rod stabilization for the treatment of multilevel degenerative lumbar spinal stenosis

Background

This study compares the use of radiographic K-Rod dynamic stabilization to the rigid system for the treatment of multisegmental degenerative lumbar spinal stenosis (MDLSS).

Methods

A total of 40 patients with MDLSS who underwent surgical treatment using the K-Rod (n = 25) and rigid systems (n = 15) from March 2013 to March 2017 were assessed. The mean follow-up period was 29.1 months. JOA, ODI, VAS and modified Macnab were assessed. Radiographic evaluations included lumbar lordosis angle, ISR value, operative and proximal adjacent ROM. Changes in intervertebral disc signal were classified according to Pfirrmann grade and UCLA system.

Results

JOA, ODI and VAS changed significantly after the operation to comparable levels between the groups. However, the lumbar lordosis significantly decreased at final follow-up between both groups. The ROM of the proximal adjacent segment increased at final follow-up, but the number of fixed segment ROMs in the K-Rod group were significantly lower at the final follow-up than observed prior to the operation. In both groups, the ISR of the proximal adjacent segment decreased, most notably in the rigid group. The ISR of the non-fusion fixed segments in the K-Rod group increased post-operation and during final follow-up. The levels of adjacent segment degeneration were higher in the rigid group vs. the K-Rod group according to modified Pfirrmann grading and the UCLA system.

Conclusions

Compared with the rigid system for treatment of MDLSS, dynamic K-Rod stabilization achieves improved radiographic outcomes and improves the mobility of the stabilized segments, minimizing the influence on the proximal adjacent segment.

Clinical Comparison of Full-Endoscopic and Microscopic Unilateral Laminotomy for Bilateral Decompression in the Treatment of Elderly Lumbar Spinal stenosis: A Retrospective Study with 12-Month Follow-Up

Purpose

Although lumbar spinal stenosis (LSS) is the most common spinal disease in the elderly, there is still a confusion about the appropriate surgical treatment strategy. The aim of this study was to compare the safety and efficacy of full-endoscopic and microscopic unilateral laminotomy for bilateral decompression (ULBD) for LSS in elderly patients.

Patients and Methods

A retrospective analysis of 61 consecutive elderly patients with LSS who underwent either full-endoscopic (FE group) or microscopic (Micro group) unilateral laminotomy for bilateral decompression was performed. Clinical data were assessed before 2 weeks, 3 months, 6 months and 12 months after surgery using the Visual Analog Scale (VAS), the Oswestry Disability Index (ODI) and the modified MacNab criteria.

Results

There are no significant differences in VAS (back and leg) and ODI between the two groups. However, the VAS back pain in the FE group was significantly improved compared to the Micro group at 2 weeks. The rate of excellent or good outcomes was 87.88% and 85.71% in the FE and Micro group, respectively (P>0.05). The hospital stay and early ambulation in FE group were shorter than those in Micro group, but the operation time was longer (P<0.05). The complications between the FE group (18.18%) and the Micro group (17.86%) were minor (P>0.05).

Conclusion

Both full-endoscopic and microscopic decompression have achieved favorable clinical results in treating elderly lumbar spinal stenosis, and the complications are minor. Full-endoscopic decompression has the advantages of small incision and rapid recovery, which can be used as an alternative for the treatment of lumbar spinal stenosis, especially the elderly with comorbidities.

Reoperation Rates after Laminoplasty for Cervical Disorders: A 26-Year Period Survival Function Method Analysis

Introduction

Laminoplasty is a common surgery for cervical myelopathy. Previous studies have analyzed the reoperation rates in posterior decompression surgeries of the cervical spine. However, few studies have solely focused on midline-splitting laminoplasty (MSL) using a large number of patients. This aims to analyze the reoperation rates after MSL using the survival function method.

Methods

Between 1988 and 2013, 4,208 MSLs were performed as a primary operation for cervical myelopathy and enrolled in our spinal surgery registration system. The Kaplan-Meier survival function method was used to analyze the rates of reoperation.

Results

Of 4,208 patients with primary MSL, 40 underwent reoperation for neurological complications. The overall reoperation rate was 0.26%, 0.64%, 0.83%, 0.93%, and 0.95% at 1, 5, 10, 20, and >20 years, respectively. The causes of reoperation were postoperative cervical radiculopathy in 10 patients, stenosis at an adjacent level in 8, stenosis due to failed “open-door” lamina in 6, instability of the cervical spine in 4, cervical disc herniation in 3, elongation of ossification of the posterior longitudinal ligament in 3, spinal cord injury in 1, fracture of the cervical spine in 1, postoperative scar formation in 1, ossification of anterior longitudinal ligament in 1, and unknown in 2. The number of patients with surgical site infection (SSI) who needed surgical debridement was 34 (0.81%).

Conclusions

Excluding reoperations for SSI, the reoperation rate of MSL was approximately 1.0% at the maximum of 26 years after surgery. MSL was determined to be a reliable surgical procedure regarding postoperative complications requiring additional surgeries.

Relationship of endplate changes and low back pain after discectomy

OBJECTIVES

Discectomy is a conventional surgery for lumbar disc herniation. However, recurrence and residual back pain are the main postoperative complications. The contribution of endplate changes to the occurrence of these complications remains controversial. This study aimed to investigate the effect of endplate changes after discectomy.

PATIENTS AND METHODS

We conducted a retrospective evaluation of 128 patients who had endplate changes after undergoing discectomy in our hospital. The patients were divided into three groups according to severity of abnormality according the Weishaupt classification (mild, moderate, and severe). The Oswestry Disability Index (ODI) and visual analog scale (VAS) were used to evaluate the efficacy of different surgical methods.

RESULTS

Seventeen patients dropped out of the follow-up study. Satisfactory efficacy was observed in most patients, but 16 patients underwent reoperation. Significant differences were observed among the three groups in terms of low back pain severity and ODI (p < 0.05), but not radicular leg pain severity. The severe group had a higher recurrence rate of disc herniation (23.5%) than the mild and moderate groups (10.3% and 10.4%, respectively).

CONCLUSION

Discectomy had a noticeable efficacy. However, severe endplate changes, which indicated fissures on the endplate, damaged the lumbar stability and resulted in a higher recurrence rate and residual back pain. For such cases, internal fixation surgery should be considered.

[Percutaneous full-endoscopic bilateral decompression via unilateral posterior approach for lumbar spinal stenosis]

OBJECTIVE

To design the surgical strategy of percutaneous full-endoscopic bilateral decompression via unilateral posterior approach for bilateral lumbar spinal stenosis (LSS) and to evaluate the effectiveness.

METHODS

The percutaneous full-endoscopic bilateral decompression via unilateral posterior approach for bilateral LSS was designed according to the pathological features of LSS. The technique was used to treat 42 patients with LSS between January 2016 and January 2018. There were 18 males and 24 females with an average age of 61.7 years (range, 46-81 years). The duration of symptoms was 1-20 years, with an average of 9.7 years. The surgical segment at L 4, 5 were 27 cases, at L 5, S 1 were 15 cases. The operation time and perioperative complications were recorded. Lumbar X-ray, CT, and MRI examinations were performed at 1 week, 3 months, and 1 year after operation. Visual analogue scale (VAS) score was used to evaluate the low back pain and leg pain, Oswestry disability index (ODI) was used to evaluate the lumbar function, and single continuous walking distance (SCWD) was used to evaluate lower extremity nerve function. The clinical efficacy was evaluated by MacNab criteria at 1 year after operation.

RESULTS

All patients underwent surgery successfully. The operation time was 68-141 minutes with an average of 98.2 minutes. All 42 patients were followed up 12-24 months with an average of 18.8 months. There were 2 cases of dural tears during operation, and 1 case of transient dysfunction of the lower limbs of the decompression channel after operation. All of them were cured after corresponding treatment. No serious complications such as death, major bleeding, or irreversible nerve injury occurred during follow-up. No segmental instability was found according to postoperative lumbar hyperextension and flexion X-ray films, and postoperative CT and MRI imaging showed that the stenotic lumbar spinal canal was significantly enlarged, and the compression of the nerve root was sufficient. The VAS score of low back pain and leg pain, ODI score, and SCWD at each time point after operation were significantly improved when compared with those before operation ( P<0.05); the indexes were significantly improved over time after operation, and the differences were significantly ( P<0.05). The clinical efficacy was evaluated by MacNab standard at 1 year after operation, and the results were excellent in 18 cases, good in 20 cases, fair in 3 cases, and poor in 1 case. The excellent and good rate was 90.5%.

CONCLUSION

The percutaneous full-endoscopic bilateral decompression via unilateral posterior approach for LSS is a safe and effective procedure. A well-designed surgical strategy and mastery of its technical points are important guarantees for successful operation and satisfactory results.

An epidemiological study of traumatic spinal cord injuries in the fastest aging area in Japan

STUDY DESIGN

Retrospective epidemiological study.

OBJECTIVE

To investigate the epidemiology of traumatic spinal cord injury (TSCI) in the fastest aging area in Japan.

SETTING

Hospitals in Akita Prefecture, Japan. Akita Prefecture has the highest ratio of people aged 65 or older in Japan (30.4% in 2012 and 34.6% in 2016).

METHODS

Patients with acute TSCI who required hospital treatment between 2012 and 2016 were included. The incidence of TSCI, cause, level, skeletal injury, and Frankel grade were investigated.

RESULTS

The mean annual incidence of TSCI excluding Frankel E was 86 per million (range 86-104 per million) during the 5-year study period, with a mean age of 65.9 years (male, 75.1%) and patients in their 60s as the largest age group. Cervical injury was seen in 89.8%, and cervical TSCI without skeletal injury was seen in 65.5%. Frankel D was the most common neurological deficit (53.5%). The most common cause was falls on level surfaces (32.1%), followed by low falls (21.6%) and road traffic accidents (15.6%).

CONCLUSIONS

Recent incidence and characteristics of TSCI in the fastest aging society in Japan are presented. The incidence of incomplete cervical TSCI and falls on level surfaces appear to be increasing.

The most influential publications in cervical myelopathy

Management of cervical myelopathy (CM) has continued to evolve through a better understanding of the long-term outcomes of this diagnosis as well as improved diagnostic guidelines. More recent literature continues to expand the field, but certain publications can be distinguished from others due to their lasting impact. Using the Clarivate Analytics Web of Science, search phrases were used to identify publications pertaining to CM. The fifty most cited articles were isolated. The frequency of citations, year of publication, country of origin, journal of publication, level of evidence (LOE), article type, as well as contributing authors and institutions were recorded. We also highlighted the five most cited articles (per year) from the past 10 years. Publications included ranged from 1952-2011, with the plurality of articles published during 2000-2009 (n=21; 42%). The most cited paper was Hillibrand's 1999 reporting of adjacent segment disease rates following cervical fusions, followed by Hirabayashi's 1983 review of his cervical laminoplasty outcomes. The third most cited was Brain's 1952 review of the manifestations of cervical spondylosis. Spine contributed the most publications (n=26; 52%). A LOE of III was the most common (n=30; 60%). Clinical outcome articles were the most frequent type (n=28; 56%). Osaka University (Japan) and Kazou Yonenobu had the most contributions. Ames or Fehlings were the first or last author in each of the five most influential articles from the past 10 years. This bibliometric citation analysis identifies the most influential articles regarding CM. There are few publications with a high LOE, and more high powered studies are needed. Knowledge of these "classic" publications allows for a better overall understanding of the diagnosis, treatment, and future direction of research of CM.

The Top 50 Most-Cited Articles on Cervical Spondylotic Myelopathy

BACKGROUND

Cervical spondylotic myelopathy (CSM) occurs due to chronic degenerative changes in the cervical spine causing compression of the spinal cord. CSM has been studied for decades, and numerous articles have been published on the topic. We sought to identify the top 50 most-cited articles on CSM.

METHODS

The top 50 most-cited articles were retrieved from the Scopus database using the search criteria "cervical spondylosis with myelopathy" OR "cervical spondylotic myelopathy." Levels of evidence were also calculated and descriptive and statistical analyses were carried out.

RESULTS

The total number of citations of the top 50 most-cited papers was 7072. The paper with the highest number of citations had 287. All articles were published between 1966 and 2010, with most published between 1990 and 1999 (n = 22). The most prolific country in terms of the total number of publications was United States, with 25 publications, followed by Japan. The majority of the articles were level IV.

CONCLUSIONS

There is a deficiency of high-level articles in the top 50 most-cited list. This study provides an important overview of historical development of treatment methods, as well as publication trends related to this pathology. Regardless, this comprehensive list of the top 50 most-cited articles can serve as a resource for future trainees and surgeons to draw on to build their knowledge base.

Rate of spinal surgery in a rapidly aging society: the 27-year changes in Miyagi prefecture, Japan

BACKGROUND

Japan has had a rapidly aging population during the past 30 years. This study aimed to investigate longitudinal changes in the surgical rate for spinal disorders in Miyagi Prefecture (2.35 million inhabitants) with a similar population composition to Japan.

METHODS

Data of spinal surgeries were collected using the spine registry by Tohoku University Spine Society. Data on the annual number of spinal surgeries between 1988 and 2014 of all populations, in those aged ≥65 years old, in those aged ≥75 years old, and for each pathology were collected. The annual surgical rate per 100,000 inhabitants was calculated.

RESULTS

The surgical rate in 2010-2014 in total, at ≥65 years old, and at ≥75 years old showed 3.2-, 3.8- and 7.1-fold increases, respectively, compared with that in 1988-1989. Degenerative spinal disorders, spinal trauma and pyogenic spondylitis markedly increased, while metastatic spinal tumor and tuberculous spondylitis decreased over time. The surgical rate at ≥75 years with lumbar spinal stenosis showed a 12.6-time increase.

CONCLUSIONS

During a rapid period of aging, the rate of spinal surgeries has markedly increased, particularly, that for degenerative disorders. This is the first report on the long-term longitudinal changes in the rate of spinal surgery.

Length of stay, costs, and complications in lumbar disc herniation surgery by standard PLIF versus a new dynamic interspinous stabilization technique

BACKGROUND

The number of lumbar spine surgeries has been increasing during the last 20 years, which also leads to an increase in hospital costs and complications related to surgery. Therefore, there is a greater concern about the costs and safety of the techniques and implants used.

METHODS

Patients (aged from 18 to 50 years) presenting with lumbago /sciatica (ICD-10-CM M54.3, M54.4) due to lumbar disc herniation lasting more than 12 weeks, were included. Patients with disc herniation larger than size-2 or size-3 according to the MSU Classification were eligible for participation. Intervention was divided in two groups. In Group 1, patients underwent microdiscectomy and Interspinous Dynamic Stabilization System (IDSS). Meanwhile, in Group 2, patients received discectomy and posterior lumbar interbody fusion (PLIF). The primary outcome measure was the length of stay and costs during hospital admission. We also evaluated several other outcome parameters, including 90- day readmission rate, 90-day complication rate, and re-operations rate. The study was an observational prospective cohort study carried out from January 2015 to August 2016 in which two surgical techniques were compared. Our hypothesis was that a less aggressive procedure, such as discectomy and DSS, will decrease the length of stay and costs, and that it will also reduce the rate of complications with respect to PLIF.

RESULTS

A total of 67 patients (mean age 39.8 ± 8.4 years) were included. Patients in the PLIF group had a length of stay increase of 109% (4.52 ± 1.76 days vs 2.16 ± 1.18 days p < 0.001) and an in-hospital cost increase of 71% (1821.97 ± 460.41€ vs. 1066.20 ± 284.34€ p < 0.001). The reduction of one day of stay is equivalent to a reduction of total in-hospital costs of 12.5%. Patients in the IDSS cohort had no significant differences regarding PLIF cohort in the 90-day readmission rate (12.9% vs 11.1% € p > 0.999, respectively), 90-day re-operation rate (12.9% vs 11.1% € p > 0.999) and 90-day complication rates (35.5% vs 52.8% € p > 0.156). Dural tear and urinary tract infection rates were higher in the PLIF cohort (13.9% vs 3.2%. p = 0.205 and 11.1% vs 0% p = 0.118, respectively). Implant related complications were the most frequent in both IDSS and PLIF groups (32.3% vs 38.9% p = 0.572).

CONCLUSIONS

Patients who underwent IDSS had a significant decrease of the length of stay and costs in relation to PLIF group. No significant differences were found in 90-day readmission and reintervention rates for both groups. Although differences were not significant, dural tear and urinary tract infection rates were lower in the interspinous group. IDSS or PLIF after discectomy, did not protect against subsequent 90-day re-operation or readmission compared to discectomy alone.