Clinical outcome of microsurgical bilateral decompression via unilateral approach for lumbar canal stenosis: minimum five-year follow-up

Reoperations After Percutaneous Endoscopic Transforaminal Decompression for Treating Lumbar Spinal Stenosis: Incidence and Predictors

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

The main purpose of the present study was to report the incidence and identify predictors of reoperation in patients with lumbar spinal stenosis (LSS) treated with percutaneous endoscopic transforaminal decompression (PETD).

METHODS

This study retrospectively reviewed consecutive patients with LSS who underwent PETD at our center between January 2016 and July 2020. The incidence of reoperations was calculated. We then designed a surgical period-matched case-control study to identify predictors among demographic data, clinical baseline data, and imaging parameters.

RESULTS

This study identified 496 eligible patients. 33 (6.7%) patients underwent reoperation with a mean follow-up of 3 years, consisting 22 (4.4%) at the index level and 11 (2.2%) at the adjacent levels. There were significant differences in age and age-adjusted Charlson comorbidity index (AACCI) between the two groups, with younger age (P = .004) and lower AACCI (P = .019) in reoperation group. Age was identified as the sole independent predictor (P = .006). The duration of symptoms ≥12 months (P = .034) and the presence of heart problems (P = .012) were recognized as specific predictors among patients younger than 65 years.

CONCLUSIONS

In a mean follow-up of 3 years, the incidence of reoperation in LSS treated with PETD was 6.7%. A younger age was the independent predictor for reoperation. Younger patients with the duration of symptoms ≥12 months or without heart problems were more likely to undergo a second operation. Prospective randomized controlled trials are required to confirm these findings.

Comparison of full-endoscopic and tubular-based microscopic decompression in patients with lumbar spinal stenosis: a randomized controlled trial

PURPOSE

We aimed to demonstrate non-inferiority in terms of functional outcomes in patients with lumbar spinal stenosis who underwent full-endoscopic decompression compared with tubular-based microscopic decompression.

METHODS

This prospective, randomized controlled, non-inferiority trial included 60 patients with single-level lumbar spinal stenosis who required decompression surgery. The patients were randomly assigned in a 1:1 ratio to the full-endoscopic group (FE group) or the tubular-based microscopic group (TM group). Based on intention-to-treat analysis, the primary outcome was the Oswestry Disability Index score at 24 months postoperative. The secondary outcomes included the visual analog scale (VAS) score for back and leg pain, European Quality of Life-5 Dimensions (EQ-5D) score, walking time, and patient satisfaction rate according to the modified MacNab criteria. Surgery-related outcomes were also analyzed.

RESULTS

Of the total patients, 92% (n = 55) completed a 24-month follow-up. The primary outcomes were comparable between the two groups (p = 0.748). However, the FE group showed a statistically significant improvement in the mean VAS score for back pain at day 1 and at 6, 12, and 24 months after surgery (p < 0.05). No significant difference was observed in the VAS score for leg pain, EQ-5D score, or walking time (p > 0.05). Regarding the modified MacNab criteria, 86.7% of patients in the FE group and 83.3% in the TM group had excellent or good results at 24 months after surgery (p = 0.261). Despite the similar results in surgery-related outcomes, including operative time, radiation exposure, revision rate, and complication rate, between the two groups (p > 0.05), less blood loss and shorter length of hospital stay were observed in the FE group (p ≤ 0.001 and 0.011, respectively).

CONCLUSION

This study suggests that full-endoscopic decompression is an alternative treatment for patients with lumbar spinal stenosis because it provides non-inferior clinical efficacy and safety compared with tubular-based microscopic surgery. In addition, it offers advantages in terms of less invasive surgery. Trial registration number (TRN): TCTR20191217001.

A decision tree analysis to predict clinical outcome of minimally invasive lumbar decompression surgery for lumbar spinal stenosis with and without coexisting spondylolisthesis and scoliosis

BACKGROUND CONTEXT

Implementing machine learning techniques, such as decision trees, known as prediction models that use logical construction diagrams, are rarely used to predict clinical outcomes.

PURPOSE

To develop a clinical prediction rule to predict clinical outcomes in patients who undergo minimally invasive lumbar decompression surgery for lumbar spinal stenosis with and without coexisting spondylolisthesis and scoliosis using a decision tree model.

STUDY DESIGN/SETTING

A retrospective analysis of prospectively collected data.

PATIENT SAMPLE

This study included 331 patients who underwent minimally invasive surgery for lumbar spinal stenosis and were followed up for ≥2 years at 1 institution.

OUTCOME MEASURES

Self-report measures: The Japanese Orthopedic Association (JOA) scores and low back pain (LBP)/leg pain/leg numbness visual analog scale (VAS) scores. Physiologic measures: Standing sagittal spinopelvic alignment, computed tomography, and magnetic resonance imaging results.

METHODS

Low achievement in clinical outcomes were defined as the postoperative JOA score at the 2-year follow-up <25 points. Univariate and multiple logistic regression analysis and chi-square automatic interaction detection (CHAID) were used for analysis.

RESULTS

The CHAID model for JOA score <25 points showed spontaneous numbness/pain as the first decision node. For the presence of spontaneous numbness/pain, sagittal vertical axis ≥70 mm was selected as the second decision node. Then lateral wedging, ≥6° and pelvic incidence minus lumbar lordosis (PI-LL) ≥30° followed as the third decision node. For the absence of spontaneous numbness/pain, sex and lateral olisthesis, ≥3mm and American Society of Anesthesiologists physical status classification system score were selected as the second and third decision nodes. The sensitivity, specificity, and the positive predictive value of this CHAID model was 65.1, 69.8, and 64.7% respectively.

CONCLUSIONS

The CHAID model incorporating basic information and functional and radiologic factors is useful for predicting surgical outcomes.

Less-invasive decompression procedures can reduce risk of reoperation for lumbar spinal stenosis with diffuse idiopathic skeletal hyperostosis extended to the lumbar segment: analysis of two retrospective cohorts

PURPOSE

Clinical outcomes after decompression procedures are reportedly worse for lumbar spinal stenosis (LSS) with diffuse idiopathic skeletal hyperostosis (DISH), especially DISH extended to the lumbar segment (L-DISH). However, no studies have compared the effect of less-invasive surgery versus conventional decompression techniques for LSS with DISH. The purpose of this study was to compare the long-term risk of reoperation after decompression surgery focusing on LSS with L-DISH.

METHODS

This study compared open procedure cohort (open conventional fenestration) and less-invasive procedure cohort (bilateral decompression via a unilateral approach) with ≥ 5 years of follow-up. After stratified analysis by L-DISH, patients with L-DISH were propensity score-matched by age and sex.

RESULTS

There were 57 patients with L-DISH among 489 patients in the open procedure cohort and 41 patients with L-DISH among 297 patients in the less-invasive procedure cohort. The reoperation rates in L-DISH were higher in the open than less-invasive procedure cohort for overall reoperations (25% and 7%, p = 0.026) and reoperations at index levels (18% and 5%, p = 0.059). Propensity score-matched analysis in L-DISH demonstrated that open procedures were significantly associated with increased overall reoperations (hazard ratio [HR], 6.18; 95% confidence interval [CI], 1.37-27.93) and reoperations at index levels (HR, 4.80; 95% CI, 1.04-22.23); there was no difference in reoperation at other lumbar levels.

CONCLUSIONS

Less-invasive procedures had a lower risk of reoperation, especially at index levels for LSS with L-DISH. Preserving midline-lumbar posterior elements could be desirable as a decompression procedure for LSS with L-DISH.

Surgical outcomes between posterior decompression alone and posterior decompression with fusion surgery among patients with Meyerding grade 2 degenerative spondylolisthesis: a multicenter cohort study

Background

Whether lumbar decompression with fusion surgery is effective against Meyerding grade 2 degenerative spondylolisthesis (DS) is unknown. Therefore, the current study aimed to compare the surgical outcomes between posterior decompression alone and posterior decompression with fusion surgery among patients with grade 2 DS with central canal stenosis.

Methods

This retrospective cohort study included prospectively registered patients (n = 3863) who underwent surgery for degenerative lumbar spinal canal stenosis at nine high-volume spine centers from April 2017 to July 2019. Patients with grade 2 DS and central canal stenosis were included in the analysis. Patients with radiculopathy, including foraminal stenosis, degenerative scoliosis, and concomitant anterior spinal fusion, and those with a previous history of lumbar surgery were excluded. The participants were divided into the decompression alone group (group D) and decompression with fusion surgery group (group F). Data about patient-reported outcomes, including Numeric Rating Scale (low back pain, leg pain, leg numbness, and foot numbness), Oswestry Disability Index, EuroQol Five-Dimensional questionnaire, and 12-Item Short-Form Health Survey scores, were obtained preoperatively and 2 years postoperatively.

Results

In total, 2354 (61%) patients, including 42 (1.8%) with grade 2 DS (n = 18 in group D and n = 24 in group F), completed the 2-year follow-up. Group D had a higher proportion of female patients than group F. However, the two groups did not significantly differ in terms of other baseline demographic characteristics. Group D had a significantly shorter surgical time and lower volume of intraoperative blood loss than group F. Postoperative patient-reported outcomes did not significantly differ between the two groups, although the preoperative degree of low back pain was higher in group F than in group D. The slip degree of group D did not worsen during the follow-up period.

Conclusion

The surgical outcomes were similar regardless of the addition of fusion surgery among patients with grade 2 DS. Decompression alone was superior to decompression with fusion surgery as it was associated with a lower volume of intraoperative blood loss and shorter surgical time.

Incidence of postoperative progressive segment degeneration at decompression and adjacent segments after minimally invasive lumbar decompression surgery: a 5-year follow-up study

OBJECTIVE

There are several reported studies on the incidence of adjacent segment disease (ASD) after lumbar fusion surgery; however, the incidence of ASD after decompression surgery has not been well studied. In this study the authors aimed to investigate the incidence of progressive segment degeneration (PSD) at the decompression and adjacent segments 5 years after minimally invasive lumbar decompression surgery.

METHODS

We investigated data from 168 patients (mean age, 69.5 ± 9.2 years) who underwent bilateral microscopic or microendoscopic decompression surgery via a unilateral approach and were followed up for more than 5 years. Outcomes were self-reported visual analog scale (VAS) scores for low-back pain, leg pain, and leg numbness and physician-assessed Japanese Orthopaedic Association (JOA) scores for back pain. Changes in the disc height and movement of the adjacent lumbar segments were compared using preoperative and 5-year postoperative lateral full-length standing whole-spine radiographic images. PSD was defined as loss of disc height > 3 mm and progression of anterior or posterior slippage > 3 mm. The incidence and clinical impact of PSD were investigated.

RESULTS

The mean JOA score improved significantly in all patients from 13.4 points before surgery to 24.1 points at the latest follow-up (mean recovery rate 67.8%). PSD at the decompression site was observed in 43.5% (73/168) of the patients. The proportions of patients with loss of disc height > 3 mm and slippage progression were 16.1% (27/168) and 36.9%, respectively (62/168: 41 anterior and 21 posterior). The proportion of patients with PSD at the adjacent segment was 20.5% (35/168), with 5.4% (9/168) of the patients with loss of disc height > 3 mm and 16.0% (27/168: 13 anterior and 14 posterior) with slippage progression. There was no significant difference in the clinical outcomes between patients with and those without PSD.

CONCLUSIONS

Radiological ASD was observed even in the case of decompression surgery alone. However, there was no correlation with symptom deterioration, measured by the VAS and JOA scores.

Mid-term changes in spinopelvic sagittal alignment in lumbar spinal stenosis with coexisting degenerative spondylolisthesis or scoliosis after minimally invasive lumbar decompression surgery: minimum five-year follow-up

BACKGROUND CONTEXT

Recently, the number of patients with lumbar spinal stenosis (LSS) who present with a coexisting spinal deformity such as degenerative spondylolisthesis (DS) and scoliosis (DLS) has been increasing. Lumbar decompression without fusion can lead to a reactive improvement in the lumbar and sagittal spinopelvic alignment, even if a sagittal imbalance exists preoperatively. However, the mid- to long-term impact of the coexistence of DS and DLS on the change in sagittal spinopelvic alignment and clinical outcomes after decompression surgery remains unknown.

PURPOSE

This study aimed to investigate whether the coexistence of DS or DLS in patients with LSS is associated with differences in radiological and clinical outcomes after minimally invasive lumbar decompression surgery.

STUDY DESIGN/SETTING

A retrospective analysis of prospectively collected data.

PATIENT SAMPLE

A total of 169 patients who underwent minimally invasive lumbar decompression surgery and follow-up >5 years postoperatively.

OUTCOME MEASURES

Self-report measures: Low back pain (LBP) and/or leg pain and/or leg numbness visual analog scale (VAS) scores and the Japanese Orthopedic Association scores.

PHYSIOLOGIC MEASURES

Standing sagittal spinopelvic alignment.

METHODS

In total, 81 patients with LSS, 50 patients with LSS and DS (≥3 mm anterior slippage), and 38 patients with LSS and DLS (≥15° coronal Cobb angle) were included in the current study. Clinical and radiological outcome results before surgery and at 2 and 5 years after surgery were compared among the groups.

RESULTS

In patients with LSS with coexisting DS, the clinical outcomes at 2, and 5 years after surgery were similar to those of patients with only LSS. In patients with LSS with coexisting DLS, the VAS LBP and leg pain at 2 years after surgery was significantly higher (34.7 vs. 27.8, p=0.014; 27.8 vs. 14.7, p=0.028) and the achievement rate of the minimal clinically important difference in VAS LBP and leg pain was significantly lower than that of the LSS group (36.1% vs. 54.2%, p=0.036; 58.3% vs. 69.9%, p=0.10). The clinical outcomes except VAS leg numbness at 5 years after surgery were similar to those of patients with only LSS. The reoperation rate of the DS group was significantly lower than that of the LSS group (4.0% vs. 14.8%; p=0.01); however, the reoperation rate of the DLS group was comparable to that of the LSS group (15.8% vs. 14.8%; p=0.493). Lumbar lordosis (LL), sacral slope, pelvic tilt, and pelvic incidence-LL had significantly improved and been maintained for 5 years after the surgery in both the DS and the DLS groups. The sagittal vertical axis had improved at two-year follow-up; however, no significant difference was observed at the 5-year follow-up in both the DS, and the DLS groups.

CONCLUSIONS

Mid-term clinical outcomes in patients with LSS with and without deformity were comparable. Lumbar decompression without fusion can result in a reactive improvement in the lumbar and sagittal spinopelvic alignment, even with coexisting DS or DLS. Minimally invasive surgery could be considered for most patients with LSS.

Facet Joint Opening on Computed Tomography Is a Predictor of Poor Clinical Outcomes After Minimally Invasive Decompression Surgery for Lumbar Spinal Stenosis

STUDY DESIGN

Retrospective longitudinal cohort study.

OBJECTIVE

To investigate the impact of facet joint opening (FJO) on clinical outcomes after minimally invasive decompression surgery for lumbar spinal stenosis.

SUMMARY OF BACKGROUND DATA

Although FJOs have previously been identified as indicators of segmental spinal instability, their impact on clinical outcomes after decompression alone surgery has yet to be investigated.

METHODS

This study included 296 patients from a single institution who underwent minimally invasive surgery for lumbar spinal stenosis and were followed up for ≥5 years. Our analysis focused on identifying FJOs at the index decompression level (d-FJO) and at multiple levels (m-FJO) (i.e., ≥3 levels within the lumbar segment) using preoperative computed tomography. Clinical outcomes including reoperations, improvement ratio for Japanese Orthopaedic Association score, and achievement of a minimal clinically important difference in visual analogue scale scores for low back pain or leg pain at 5 years were compared between patients with and without d-FJO or m-FJO.

RESULTS

There were 129 (44%) and 62 (21%) patients with d-FJO (more common with lateral olisthesis) and m-FJO (less common with spondylolisthesis), respectively. Reoperations were more common in patients with d-FJO than in those without (16% vs. 5%). On Cox proportional hazards analysis, d-FJO was identified as a predictor for revision at the index decompression level (hazard ratio 4.04, P = 0.03), whereas m-FJO was a predictor for revision at other lumbar levels (hazard ratio 3.71, P = 0.03). Patients with m-FJO had slightly lower rates of achieving minimal clinically important difference in visual analogue scale scores for low back pain (34% vs. 52%, P = 0.03) and poorer improvement ratio for Japanese Orthopaedic Association scores (74% vs. 80%, P = 0.03) than those without.

CONCLUSION

FJO at both index decompression level and multiple level were predictors of poor outcomes; patients with FJOs require careful surgical planning or special follow-up.Level of Evidence: 3.

Prevalence of Restless Legs Syndrome and its Symptoms among Patients with Spinal Disorders

Restless legs syndrome (RLS) is a neurological disorder that causes uncomfortable sensations in the legs. The purpose of this study was to evaluate the symptoms of RLS in patients with spinal disorders and the impact of RLS on the clinical outcomes of lumbar spinal stenosis (LSS). The records of 278 patients (age range 65–92 years) with spinal disorders who visited our outpatient clinic were reviewed. We used a survey to identify subjects with RLS based on the International RLS Study Group diagnostic criteria. We further recorded patient characteristics, surgical outcomes, sleeping time, mental health condition, and the occurrence of leg cramps. Thirty-two patients (11.5%) met the criteria for RLS. The prevalence of anxiety (46.9% vs. 26.6%, p = 0.023) and leg cramps (90.6% vs. 73.2%, p = 0.030) was higher in patients with RLS than in those without. RLS was present in 12.3% of LSS patients. The visual analog scale score for lower back pain before surgery and at the final follow-up was significantly higher in LSS patients with RLS than in those without. However, the Japanese Orthopaedic Association (JOA) score, JOA score improvement ratio, and VAS score for leg numbness were not significantly different between the groups.

Relationship between facet joint opening on CT and facet joint effusion on MRI in patients with lumbar spinal stenosis: analysis of a less invasive decompression procedure

OBJECTIVE

Both facet joint opening (FJO) on CT and facet joint effusion (FJE) on MRI are reportedly indicators of segmental instability in the lumbar facet joints of patients with lumbar spinal stenosis (LSS). However, no study has investigated both parameters simultaneously. Therefore, the association between these findings and which parameter is better for predicting clinical outcomes after surgical treatment remains unclear. The purpose of this study was to investigate the relationship between FJO and FJE in patients who underwent less invasive decompression procedures for LSS and to investigate the impact of these findings on clinical outcomes.

METHODS

This study included 1465 lumbar levels (L1-2 to L5-S1) in 293 patients who underwent less invasive surgery for LSS and had ≥ 5 years of follow-up. FJO was defined as joint space widening ≥ 2 mm on preoperative axial CT images. FJE was defined as fluid effusion in the facet joint on preoperative axial T2-weighted MR images. The characteristics and distributions of FJO and FJE were investigated with other preoperative radiological findings. The association between need for further surgery and FJO/FJE was analyzed according to intervertebral level.

RESULTS

FJO was observed at 402 levels (27%), and FJE was found at 306 levels (21%). The correspondence rate between FJO and FJE was 70% (kappa 0.195, p < 0.01). One hundred thirty-seven levels (9%) had both FJO and FJE. Levels with both FJO and FJE more commonly had lateral olisthesis, lateral wedging, and axial intervertebral rotation than other levels (p < 0.001). Levels with both FJO and FJE were more likely than other levels to need further surgery (OR 2.42, p = 0.027).

CONCLUSIONS

The correspondence rate between FJO and FJE was not high. However, multivariate analysis showed that levels with both FJO and FJE had a higher risk of requiring further surgery than those with other radiological findings, such as lateral olisthesis, lateral wedging, and axial intervertebral rotation. Patients with levels with both FJO and FJE need careful long-term follow-up after undergoing a less invasive decompression procedure.

Long-Term Pain Characteristics and Management Following Minimally Invasive Spinal Decompression and Open Laminectomy and Fusion for Spinal Stenosis

Background and Objectives: To compare the long-term pain characteristics and its chronic management following minimally invasive spinal (MIS) decompression and open laminectomy with fusion for lumbar stenosis. Materials and Methods: The study cohort included patients with a minimum 5-year postoperative follow-up after undergoing either MIS decompression or laminectomy with fusion for spinal claudication. The primary outcome of interest was chronic back and leg pain intensity. Secondary outcome measures included pain frequency during the day, chronic use of non-opioid analgesics, narcotic medications, medical cannabinoids, and continuous interventional pain treatments. Results: A total of 95 patients with lumbar spinal stenosis underwent one- or two-level surgery for lumbar spinal stenosis between April 2009 and July 2013. Of these, 50 patients underwent MIS decompression and 45 patients underwent open laminectomy with instrumented fusion. In the fusion group, a higher percentage of patients experienced moderate-to-severe back pain with 48% compared to 21.8% of patients in the MIS decompression group (p < 0.01). In contrast, we found no significant difference in the reported leg pain in both groups. In the fusion group, 20% of the patients described their back and leg pain as persistent throughout the day compared to only 2.2% in the MIS decompression group (p < 0.05). A trend toward higher chronic dependence on analgesic medication and repetitive pain clinic treatments was found in the fusion group. Conclusions: MIS decompression for the treatment of degenerative spinal stenosis resulted in decreased long-term back pain and similar leg pain outcomes compared to open laminectomy and instrumented fusion surgery.

Clinical Outcomes of Minimally Invasive Posterior Decompression for Lumbar Spinal Stenosis with Degenerative Spondylolisthesis

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To compare the clinical outcomes 5 years after minimally invasive posterior decompression for lumber spinal stenosis (LSS) between patients with and without degenerative spondylolisthesis (DS).

SUMMARY OF BACKGROUND DATA

Indications for surgical procedures for patients with LSS and DS are still under investigation. Since minimally invasive surgery does not affect most anatomical structures, preoperative DS may not negatively affect the clinical outcomes of minimally invasive posterior decompression.

METHODS

Overall, 198 patients with LSS who underwent microendoscopic or microscopic decompression and were followed up for more than 5 years postoperatively were included in the present study. Patients who showed a segmental kyphosis >5° at the surgical level during flexion were treated with fusion surgery. However, other patients, including those with DS, were treated with posterior decompression. The patients were divided into two groups: the DS group included 82 patients with >3-mm slip and the non-DS group included 112 patients with ≤3-mm slip or without slip. A mixed-effects model adjusted for age and sex was used to compare the improvements in the visual analog scale score for low-back pain and the Japanese Orthopaedic Association score of the two groups. For subgroup analysis (n = 53), the changes in the preoperative physical component summary and the mental component summary of Short Form-36 of the two groups at 5 years after surgery were evaluated.

RESULTS

There was no significant difference in the improvement of preoperative low-back pain visual analog scale score and Japanese Orthopaedic Association score 5 years after surgery between the two groups. Subgroup analysis showed no significant difference between the two groups in the improvement of preoperative physical component summary and mental component summary 5 years after surgery.

CONCLUSION

After carefully eliminating patients with segmental instability, DS did not affect the clinical outcomes of minimally invasive decompression surgery.Level of Evidence: 3.

The effect of minimally invasive lumbar decompression surgery on sagittal spinopelvic alignment in patients with lumbar spinal stenosis: a 5-year follow-up study

OBJECTIVE

Several studies have examined the relationship between sagittal spinopelvic alignment and clinical outcomes after spinal surgery. However, the long-term reciprocal changes in sagittal spinopelvic alignment in patients with lumbar spinal stenosis after decompression surgery remain unclear. The aim of this study was to investigate radiographic changes in sagittal spinopelvic alignment and clinical outcomes at the 2-year and 5-year follow-ups after minimally invasive lumbar decompression surgery.

METHODS

The authors retrospectively studied the medical records of 110 patients who underwent bilateral decompression via a unilateral approach for lumbar spinal stenosis. Japanese Orthopaedic Association (JOA) and visual analog scale (VAS) scores for low-back pain (LBP), leg pain, leg numbness, and spinopelvic parameters were evaluated before surgery and at the 2-year and 5-year follow-ups. Sagittal malalignment was defined as a sagittal vertical axis (SVA) ≥ 50 mm.

RESULTS

Compared with baseline, lumbar lordosis significantly increased after decompression surgery at the 2-year (30.2° vs 38.5°, respectively; p < 0.001) and 5-year (30.2° vs 35.7°, respectively; p < 0.001) follow-ups. SVA significantly decreased at the 2-year follow-up compared with baseline (36.1 mm vs 51.5 mm, respectively; p < 0.001). However, there was no difference in SVA at the 5-year follow-up compared with baseline (50.6 mm vs 51.5 mm, respectively; p = 0.812). At the 5-year follow-up, 82.5% of patients with preoperative normal alignment maintained normal alignment, whereas 42.6% of patients with preoperative malalignment developed normal alignment. Preoperative sagittal malalignment was associated with the VAS score for LBP at baseline and 2-year and 5-year follow-ups and the JOA score at the 5-year follow-up. Postoperative sagittal malalignment was associated with the VAS score for LBP at the 2-year and 5-year follow-ups and the VAS score for leg pain at the 5-year follow-up. There was a trend toward deterioration in clinical outcomes in patients with persistent postural malalignment compared with other patients.

CONCLUSIONS

After minimally invasive surgery, spinal sagittal malalignment can convert to normal alignment at both short-term and long-term follow-ups. Sagittal malalignment has a negative impact on the VAS score for LBP and a weakly negative impact on the JOA score after decompression surgery.

Classification and prognostic factors of residual symptoms after minimally invasive lumbar decompression surgery using a cluster analysis: a 5-year follow-up cohort study

PURPOSE

Residual symptoms indicating incomplete remission of lower leg numbness or low back pain may occur after spine surgery. The purpose was to elucidate the pattern of residual symptoms 5 years after minimally invasive lumbar decompression surgery using a cluster analysis.

METHODS

The study comprised 193 patients with lumbar spinal stenosis (LSS) (108 men, 85 women) ranging in age from 40 to 86 years (mean, 67.9 years). Each patient underwent 5-year follow-up. The Japanese Orthopedic Association score and visual analog scale scores for low back pain, leg pain, and leg numbness at 5 years were entered into the cluster analysis to characterize postoperative residual symptoms. Other clinical data were analyzed to detect the factors significantly related to each cluster.

RESULTS

The analysis yielded four clusters representing different patterns of residual symptoms. Patients in cluster 1 (57.0%) were substantially improved and had few residual symptoms of LSS. Patients in cluster 2 (11.4%) were poorly improved and had major residual symptoms. Patients in cluster 3 (17.6%) were greatly improved but had mild residual low back pain. Patients in cluster 4 (14.0%) were improved but had severe residual leg numbness. Prognostic factors of cluster 2 were a short maximum walking distance, motor weakness, resting lower leg numbness, cofounding scoliosis, and high sagittal vertical axis.

CONCLUSIONS

This is the first study to identify specific patterns of residual symptoms of LSS after decompression surgery. Our results will contribute to acquisition of preoperative informed consent and identification of patients with the best chance of postoperative improvement.

Factors Influencing Patient Satisfaction After Decompression Surgery Without Fusion for Lumbar Spinal Stenosis

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

Decompression without fusion is a standard surgical treatment for lumbar spinal stenosis (LSS) with reasonable surgical outcomes. Nevertheless, some studies have reported low patient satisfaction (PS) following decompression surgery. The cause of the discrepancy between reasonable clinical outcomes and PS is unknown; moreover, the factors associated with PS are expected to be complex, and little is known about them. This study aimed to identify satisfaction rate and to clarify the factors related to PS following decompression surgery in LSS patients.

METHODS

We retrospectively reviewed 126 patients who underwent lumbar decompression with a minimum follow-up of 1 year. Patients were divided into 2 groups based on the PS question. The Japanese Orthopaedic Association (JOA) scores, and the Numeric Rating Scale (NRS) scores of low back pain (LBP), leg pain, and leg numbness were compared between the 2 groups preoperatively and at the latest visit. To identify the prognostic factors for dissatisfaction, multiple logistic regression analysis was performed.

RESULTS

Overall satisfaction rate was 75%. The JOA recovery rate, NRS improvement, and Short Form-8 (SF-8) were significantly higher in the satisfied group. Postoperative NRS scores of LBP, leg pain, and leg numbness were significantly lower in the satisfied group. Multivariate logistic regression analysis showed that smoking and scoliosis were significant risk factors for dissatisfaction.

CONCLUSIONS

Overall satisfaction rate was 75% in patients with LSS undergoing decompression surgery. This study found that smoking status and scoliosis were associated with patient dissatisfaction following decompression in LSS patients.

[Unilateral approach for over the top bilateral lumbar decompression]

OBJECTIVE

The main goal is bilateral microsurgical decompression of the cauda equina using a unilateral over the top approach. The challenge is to achieve decompression with minimal iatrogenic trauma to anatomical structures in the approach region and in the target area.

INDICATIONS

Degenerative spinal disorders including lumbar central stenosis, lumbar lateral recess spinal stenosis, and foraminal narrowing. This technique is performed in patients presenting primarily with neurogenic claudication, leg or buttock symptoms, heaviness in the legs with or without radicular symptoms, with or without neurological deficits, and comparable MRI findings. There are no limitations regarding number of affected segments or the extent of narrowing.

CONTRAINDICATIONS

All available conservative treatment modalities not exhausted. Lack of serious neurological deficit.

SURGICAL TECHNIQUE

Minimally invasive, muscle-sparing and facet-joint-sparing bilateral enlargement of the lumbar spinal canal through a unilateral microsurgical cross-over approach.

POSTOPERATIVE MANAGEMENT

Patients are mobilized early 4-6 h postoperatively. Light sports activities (e.g., ergometer cycling, swimming) are allowed after 2 weeks. The same is true for the return to normal daily or work activities except for heavy physical work (usually 4 weeks out of work). Soft lumbar brace for 4 weeks (optional).

RESULTS

The clinical outcomes are good to excellent. Meta-analyses and large case series report success rates for microsurgical decompression procedures of 73.5-95%. The reoperation rates are low (0.5-10%).

Impact of Sarcopenia on Clinical Outcomes of Minimally Invasive Lumbar Decompression Surgery

The purpose of this study was to clarify the clinical impact of sarcopenia on the outcome of minimally invasive lumbar decompression surgery. The records of 130 patients who were >65 years and underwent minimally invasive lumbar decompression surgery were retrospectively reviewed. We collected the Japanese Orthopaedic Association (JOA) score before surgery and at the final follow-up and measured appendicular muscle mass using bioimpedance analysis, hand-grip strength and gait speed. We diagnosed the patients with sarcopenia, dynapenia and normal stages using the European Working Group on Sarcopenia in Older People definition and used cutoff thresholds according to the algorithm set by the Asian Working Group for Sarcopenia. The average age of patients undergoing surgery was 76.9 years old. The JOA score improved from 12.6 points preoperatively to 24.3 points at final follow up. The prevalence of the sarcopenia, dynapenia and normal stages was 20.0, 31.6 and 43.8%. Clinical outcomes, such as JOA score, JOA score improvement ratio, visual analog scale for low back pain, leg pain and numbness, were not significantly different among each group. Multiple regression analysis showed that preoperative JOA score and low physical performance (low gait speed) were independently associated with poor clinical outcomes. The JOA score improved after minimally invasive lumbar decompression surgery even when the patients were diagnosed as being at different stages of sarcopenia. Low physical performance had the greater clinical impact on the clinical outcome of lumbar surgery than low skeletal muscle index.

Microdecompression versus Open Laminectomy and Posterior Stabilization for Multilevel Lumbar Spine Stenosis: A Randomized Controlled Trial

Background

Lumbar spinal stenosis most often results from a gradual, degenerative ageing process. Open or wide decompressive laminectomy was formerly the standard treatment. However, in recent years, a growing tendency towards less invasive decompressive procedures has emerged. The purpose of this study was to compare the results of microdecompression with those of open wide laminectomy and posterior stabilization for patients with symptomatic multilevel lumbar spinal stenosis who failed to respond to conservative treatment.

Methods

This randomized controlled study was conducted between January 2016 and October 2018. One hundred patients were involved in this study. All these patients suffered from radicular leg pain with MRI features of multilevel lumbar spinal stenosis and were treated by conservative treatment of medical treatment and physiotherapy without benefit for 6 months. Those patients were divided into two groups: Group A, 50 microdecompression, and Group B, 50 patients who were treated by open wide laminectomy and posterior stabilization. Both groups of patients were followed up with ODI (Oswestry disability index) and VAS (visual analogue score) for the back and leg pain for one year.

Results

The results showed that both groups got significant improvement regarding the Oswestry disability index. Regarding back pain, there was a significant improvement in both groups with better results in group A due to minimal tissue injury as the advantage of the minimal invasive technique. In both groups, there was marked improvement of radicular leg pain postoperatively.

Conclusions

Both microdecompression and wide open laminectomy with posterior stabilization were effective in treatment of multilevel lumbar spinal stenosis with superior results of microdecompression regarding less back pain postoperatively with less blood loss and soft tissue dissection. Clinical trial number: NCT04087694.

[Minimally invasive decompression techniques for spinal cord stenosis]

BACKGROUND

Lumbar spinal canal stenosis is frequently found among elderly patients and significantly limits their quality of life. Non-surgical therapy is an initial treatment option; however, it does not eliminate the underlying pathology. Surgical decompression of the spinal canal has now become the treatment of choice.

OBJECTIVE

Minimalization of surgical approach strategies with maintaining sufficient decompression of the spinal canal and avoiding disadvantages of macrosurgical techniques, monolateral paravertebral approach with bilateral intraspinal decompression, specific surgical techniques.

MATERIALS AND METHODS

Minimally invasive decompression techniques using a microscope or an endoscope are presented and different surgical strategies depending on both the extent (mono-, bi-, and multisegmental) and the location of the stenosis (intraspinal central, lateral recess, foraminal) are described.

RESULTS

Minimally invasive microscopic or endoscopic decompression procedures enable sufficient widening of the spinal canal. Disadvantages of macrosurgical procedures (e. g., postoperative instability) can be avoided. The complication spectrum overlaps partially with that of macrosurgical interventions, albeit with significantly less marked severity. Subjective patient outcome is clearly improved.

CONCLUSIONS

Referring to modern minimally invasive decompression procedures, surgery of lumbar spinal canal stenosis represents a rational and logical treatment alternative, since causal treatment of the pathology is only possible with surgery.

Microendoscopic Decompression for Lumbar Spinal Stenosis With Degenerative Spondylolisthesis: The Influence of Spondylolisthesis Stage (Disc Height and Static and Dynamic Translation) on Clinical Outcomes

STUDY DESIGN

This study was a retrospective subgroup analysis of prospective cohort data.

OBJECTIVE

The main objectives of this study were to develop a classification of degenerative spondylolisthesis (DS) and concurrent lumbar spinal stenosis (LSS) based on pathologic stage, and to determine how these subtypes of DS affect outcomes for minimally invasive (MIS) decompression SUMMARY OF BACKGROUND DATA:: DS with LSS is a common clinical scenario, yet there is no consensus on optimal treatment. Natural history of DS is described as early degenerative damage, followed by instability, and eventual restabilization via spondylotic changes. MIS decompression surgery has become increasingly popular, but the effect of DS subtypes on clinical outcomes after MIS decompression is unknown.

PATIENTS AND METHODS

From 2008 to 2013, all patients who underwent microendoscopic laminotomy for single-level LSS with DS were included. In total, 218 patients (91 male, 127 female individuals) were reviewed. DS pathologic staging was defined as early, advanced, or end stage, based on percent slippage (10% slippage), degree of dynamic instability (3 mm), and disc height. The following variables were evaluated preoperatively and >2 years postoperatively and compared among groups: Japanese Orthopaedic Association (JOA) score, JOA recovery rate, and Visual Analog Scale low back pain.

RESULTS

In total, 173 patients were included in final analysis. Final follow-up period was 2.3 years. Average JOA recovery rate was 63.8%. There were no significant differences in JOA recovery and Visual Analog Scale among 3 DS stages (P>0.05). In total, 9.8% of patients required additional spine surgery, with 5% requiring subsequent fusion. All patients who required subsequent fusion were in the advanced stage DS group.

CONCLUSIONS

Microendoscopic decompression is an effective treatment for patients with DS and concurrent LSS, with only 5% of patients requiring subsequent fusion at over 2-year follow-up, and another 5% requiring revision or adjacent segment decompression. The advanced stage DS group, indicating a >10% anterolisthesis and/or >3 mm of dynamic instability, was more likely to require additional surgery.

Does Concomitant Degenerative Spondylolisthesis Influence the Outcome of Decompression Alone in Degenerative Lumbar Spinal Stenosis? A Meta-Analysis of Comparative Studies

OBJECTIVE

To investigate whether the preoperative presence of degenerative spondylolisthesis (DS) worsens the outcome of patients undergoing decompression alone for degenerative lumbar stenosis.

METHODS

We conducted a comprehensive search in the PubMed, Embase, and Cochrane Library databases. All comparative studies were included in this meta-analysis. The literature search, data extraction, and quality assessment were conducted by 2 independent reviewers. The functional outcomes were clinical scores and reoperation rate. The radiologic outcomes were slippage rate and postoperative instability rate.

RESULTS

A total of 11 studies with 1081 cases, including 469 cases of degenerative lumbar stenosis with DS (DS group) and 612 degenerative lumbar stenosis without spondylolisthesis (noDS group), were enrolled in our meta-analysis. There were no significant differences between the 2 groups for functional outcomes in terms of Japanese Orthopedic Association score, Japanese Orthopedic Association recovery rate, Oswestry Disability Index score, visual analog scale back/leg, and reoperation rate after decompression alone. For the radiologic outcomes, slippage rate was found not changed significantly before and after minimally invasive decompression alone in the DS group and the postoperative instability rate did not differ significantly between the 2 groups after decompression alone by a minimally invasive method.

CONCLUSIONS

Our meta-analysis revealed that concomitant DS (Meyerding grade I-II) does not influence the outcome of decompression alone in degenerative lumbar spinal stenosis, especially when a minimally invasive procedure was performed and patients did not have predominant symptoms of mechanical back pain. The presence of DS should not be an indication for fusion surgery in degenerative lumbar spinal stenosis.

Surgical Outcomes and Limitations of Decompression Surgery for Degenerative Spondylolisthesis

STUDY DESIGN

A retrospective study.

OBJECTIVES

To investigate surgical outcomes and limitations of decompression surgery for degenerative spondylolisthesis.

METHODS

One hundred patients with degenerative spondylolisthesis who underwent decompression surgery alone were included in this study. The average follow-up period was 3.7 years. Radiography and magnetic resonance imaging were used for radiological assessment. Patients with a recovery rate of >50% throughout the study period were classified as the control group (Group C), while those with a recovery rate of <50% throughout the study period were classified as the poor group (Group P). Patients that had improved symptoms, and yet later showed neurological deterioration due to foraminal stenosis at the same level were classified as the exiting nerve root radiculopathy group (Group E), while those who showed deterioration due to slip progression at the same level were classified as the traversing nerve root radiculopathy group (Group T).

RESULTS

Patient distribution in each group was 73, 12, 7, and 8 in Groups C, P, E, and T, respectively. As for preoperative radiological features, slippage and an upper migrated disc in Group P, disc wedging and an upper migrated disc in Group E, and lamina inclination and posterior opening in Group T were evident. The cutoff value of preoperative slippage with a poor outcome was 13%.

CONCLUSIONS

Surgical outcomes of decompression surgery for degenerative spondylolisthesis were successful in 73% cases. Preoperative radiological features for poor outcomes were slippage of more than 13%, an upper migrated disc, disc wedging, and lamina inclination.

Comparison of minimally invasive decompression and combined minimally invasive decompression and fusion in patients with degenerative spondylolisthesis with instability

Posterior lumbar interbody fusion with cortical bone trajectory (CBT-PLIF) is a form of minimally invasive decompression and fusion, whereas microendoscopic laminotomy (MEL) is a form of minimally invasive decompression surgery. No study has compared the clinical outcomes of the two methods for patients who have degenerative spondylolisthesis (DS) with instability. In this study, CBT-PLIF and MEL were both offered to 64 patients who met the inclusion criteria. Each patient then selected his or her preferred treatment. Twenty patients received CBT-PLIF. They were matched to 30 of the 44 patients receiving MEL based on age, sex, disease duration, and surgical levels. The 20 patients with CBT-PLIF formed the CBT group and the 30 matched patients with MEL formed the MEL group. At 2 years of follow-up, Japanese Orthopaedic Association scores improved to 72.6% and 70.5% in the CBT and MEL groups, respectively. The difference in scores was not statistically significant. Further, improvements in visual analogue scale scores for back and leg symptom did not differ significantly between the two groups. Regarding complications, 1 CBT-group patient (5%) had adjacent-segment degeneration and 7 MEL-group patients (23%) had same-segment degeneration. Three CBT-group patients (15%) and 5 MEL-group patients (16%) required reoperation within the follow-up period. In summary, among patients who had DS with instability, MEL and CBT-PLIF offered comparable clinical outcomes at 2 years of follow-up. Although the rate of segmental degeneration was relatively high in the MEL group, both groups had similar reoperation rates.

Clinical Outcome of Muscle-Preserving Interlaminar Decompression (MILD) for Lumbar Spinal Canal Stenosis: Minimum 5-Year Follow-Up Study

Introduction

Favorable short-term outcomes have been reported following muscle-preserving interlaminar decompression (MILD), a less invasive decompression surgery for lumbar spinal canal stenosis (LSCS). However, there are no reports of mid- to long-term outcomes. The purpose of this study was to evaluate the clinical outcomes five or more years after treatment of LSCS with MILD.

Methods

Subjects were 84 cases with LSCS (44 males; mean age, 68.7 years) examined five or more years after MILD. All patients had leg pain symptoms, with claudication and/or radicular pain. The patients were divided into three groups depending on the spinal deformity: 44 cases were without deformity (N group); 20 had degenerative spondylolisthesis (DS group); and 20 had degenerative scoliosis (DLS group). The clinical evaluation was performed using Japanese Orthopedic Association (JOA) scores, and revision surgeries were examined. Changes in lumbar alignment and stability were evaluated using plain radiographs.

Results

The overall JOA score recovery rate was 65.5% at final follow-up. The recovery rate was 69.5% in the N group, 65.2% in the DS group, and 54.0% in the DLS group, with the rate of the DLS group being significantly lower. There were 16 revision surgery cases (19.0%): seven in the N group (15.9%), three in the DS group (15.0%) and six in the DLS group (30.0%). There were no significant differences between pre- and postoperative total lumbar alignment or dynamic intervertebral angle in any of the groups, slip percentage in the DS group, or Cobb angle in the DLS group.

Conclusions

The mid-term clinical results of MILD were satisfactory, including in cases with deformity, and there was no major impact on radiologic lumbar alignment or stability. The clinical outcomes of cases with degenerative scoliosis were significantly less favorable and the revision rate was high. This should be taken into consideration when deciding on the surgical procedure.

Current trends in the management of degenerative lumbar spondylolisthesis

Degenerative spondylolisthesis (DS) is a common disease of the degenerative spine, often associated with lumbar canal stenosis. However, the choice between the different medical or surgical treatments remains under debate.

Preference for surgical strategy is based on the functional symptoms, and when surgical treatment is selected, several questions should be posed and the surgical strategy adapted accordingly.

One of the main goals of surgery is to improve neurological symptoms. Therefore, radicular decompression may be necessary. Radicular decompression can be performed indirectly through interbody fusion or interspinous spacer. However, indirect decompression has some limits, and the most frequent technique is a posterior decompression with fusion.

Indeed, in cases of DS, associated fusion or dynamic stabilization are recommended to improve functional outcomes and prevent future destabilization. Risk factors for destabilization, such as anteroposterior and angular mobility, and significant disc height, have been discussed in the literature. When fusion is performed, osteosynthesis is often associated. It is essential to choose the length and position of the fusion according to the pelvic incidence and global alignment of the patient. It is possible to add interbody fusion to the posterolateral arthrodesis to improve graft area and stability, increase local lordosis and open foramina.

The most common surgical treatment for DS is posterior decompression with instrumented fusion. Nevertheless, some cases are more complicated and it is crucial to consider the patient’s general health status, symptoms and alignment when selecting the surgical strategy.

Cite this article: EFORT Open Rev 2018;3 DOI: 10.1302/2058-5241.3.170050

Lumbar Spinal Stenosis Associated With Degenerative Lumbar Spondylolisthesis: A Systematic Review and Meta-analysis of Secondary Fusion Rates Following Open vs Minimally Invasive Decompression

Background

Decompression without fusion is a treatment option in patients with lumbar spinal stenosis (LSS) associated with stable low-grade degenerative spondylolisthesis (DS). A minimally invasive unilateral laminotomy (MIL) for "over the top" decompression might be a less destabilizing alternative to traditional open laminectomy (OL).

Objective

To review secondary fusion rates after open vs minimally invasive decompression surgery.

Methods

We performed a literature search in Pubmed/MEDLINE using the keywords "lumbar spondylolisthesis" and "decompression surgery." All studies that separately reported the outcome of patients with LSS+DS that were treated by OL or MIL (transmuscular or subperiosteal route) were included in our systematic review and meta-analysis. The primary end point was secondary fusion rate. Secondary end points were total reoperation rate, postoperative progression of listhetic slip, and patient satisfaction.

Results

We identified 37 studies (19 with OL, 18 with MIL), with a total of 1156 patients, that were published between 1983 and 2015. The studies' evidence was mostly level 3 or 4. Secondary fusion rates were 12.8% after OL and 3.3% after MIL; the total reoperation rates were 16.3% after OL and 5.8% after MIL. In the OL cohort, 72% of the studies reported a slip progression compared to 0% in the MIL cohort, respectively. After OL, satisfactory outcome was 62.7% compared to 76% after MIL.

Conclusion

In patients with LSS and DS, minimally invasive decompression is associated with lower reoperation and fusion rates, less slip progression, and greater patient satisfaction than open surgery.

Minimally invasive techniques for lumbar decompressions and fusions

PURPOSE OF REVIEW

The purpose of this study is to summarize the recent literature investigating the use of minimally invasive (MIS) techniques in the treatment of lumbar degenerative stenosis, spondylolisthesis, and scoliosis.

RECENT FINDINGS

MIS lumbar decompression and fusion techniques for degenerative pathology are associated with reduced operative morbidity, shortened length of hospital stay, and reduced postoperative pain and narcotics utilization. Recent studies with long-term clinical follow-up have demonstrated equivalence in clinical outcomes between open and MIS surgical procedures. Radiographically, MIS procedures provide adequate postoperative correction of coronal alignment. Correction of sagittal alignment, however, is more variable based on current reports. MIS techniques are both safe and effective in the treatment of lumbar degenerative pathologies. While some studies have reported on long-term outcomes and costs associated with MIS procedures, more investigation into these topics is still necessary. Additionally, further work is required to analyze the training requirements and learning curves of MIS procedures to better promote adoption amongst surgeons.

Radiographic Risk Factors of Reoperation Following Minimally Invasive Decompression for Lumbar Canal Stenosis Associated With Degenerative Scoliosis and Spondylolisthesis

STUDY DESIGN

Prospective cohort study.

OBJECTIVE

Microsurgical bilateral decompression via a unilateral approach (MBDU), a minimally invasive surgical (MIS) decompression method, has been performed for numerous degenerative lumbar diseases, including degenerative lumbar scoliosis (DLS) or degenerative spondylolisthesis (DS), at our institution. In this study, we evaluated the appropriateness of MBDU for DLS or DS patients.

METHODS

A total of 207 patients treated by MBDU were included (88 women and 119 men; mean age, 70 [40-86] years). Thirty-seven cases were diagnosed as DLS (group A), 51 as DS (group B), and 119 as lumbar canal stenosis (group C). Patient clinical status assessed by JOA score was evaluated preoperatively and 2 years postoperatively. We evaluated the prevalence of cases that required reoperation among the groups and the radiographic risk factors related to reoperation.

RESULTS

There was no significant difference in recovery ratios of JOA scores among the groups. Reoperation after MBDU was needed in 13 cases (6.3%); the revision rate did not significantly differ among the groups. Reoperation was associated with poor clinical status, low visual analog scale score for low back pain, and low SF-36 mental component summary score. Reoperation was significantly associated with preoperative scoliotic disc wedging with Cobb's angle ≥3° in L4-5 (odds ratio = 9.88) and lateral listhesis (odds ratio = 5.22 [total], 12.9 [L4-5]).

CONCLUSIONS

When we are careful to indicate decompression for patients with these risk factors related to reoperation, MIS decompression alone can successfully improve DLS patients with a Cobb's angle of ≤20° or DS patients.

Preoperative retrolisthesis as a predictive risk factor of reoperation due to delayed-onset symptomatic foraminal stenosis after central decompression for lumbar canal stenosis without fusion

BACKGROUND CONTEXT

For patients diagnosed with lumbar central canal stenosis with asymptomatic foraminal stenosis (FS), surgeons occasionally only decompress central stenosis and preserve asymptomatic FS. These surgeries have the potential risk of converting preoperative asymptomatic FS into symptomatic FS postoperatively by accelerating spinal degeneration, which requires reoperation. However, little is known about delayed-onset symptomatic FS postoperatively.

PURPOSE

This study aimed to evaluate the rate of reoperation for delayed-onset symptomatic FS after lumbar central canal decompression in patients with preoperative asymptomatic FS, and determine the predictive risk factors of those reoperations.

STUDY DESIGN

This study is a retrospective cohort study.

PATIENT SAMPLE

Two hundred eight consecutive patients undergoing posterior central decompression for lumbar canal stenosis between January 2009 and June 2014 were included in this study.

OUTCOME MEASURES

The number of patients who had preoperative FS and the reoperation rate for delayed-onset symptomatic FS at the index levels were the outcome measures.

METHODS

Patients were divided into two groups with and without preoperative asymptomatic FS at the decompressed levels. The baseline characteristics and revision rates for delayed-onset symptomatic FS were compared between the two groups. Predictive risk factors for such reoperations were determined using multivariate logistic regression and receiver operating characteristics analyses.

RESULTS

Preoperatively, 118 patients (56.7%) had asymptomatic FS. Of those, 18 patients (15.3%) underwent reoperation for delayed-onset symptomatic FS at a mean of 1.9 years after the initial surgery. Posterior slip in neutral position and posterior extension-neutral translation were significant risk factors for reoperation due to FS. The optimal cutoff values of posterior slip in neutral position and posterior extension-neutral translation for predicting the occurrence of such reoperations were both 1 mm; 66.7% of patients who met both of these cutoff values had undergone reoperation.

CONCLUSIONS

This study demonstrated that 15.3% of patients with preoperative asymptomatic FS underwent reoperation for delayed-onset symptomatic FS at the index levels at a mean of 1.9 years after central decompression, and preoperative retrolisthesis was a predictive risk factor for such a reoperation. These findings are valuable for establishing standards of appropriate treatment strategies in patients with lumbar central canal stenosis with asymptomatic FS.

Clinical and Radiological Outcomes after Microscopic Bilateral Decompression via a Unilateral Approach for Degenerative Lumbar Disease: Minimum 5-Year Follow-Up

Study Design

A retrospective study.

Purpose

To assess postoperative bone regrowth at surgical sites after lumbar decompression with >5 years of follow-up. Postoperative preservation of facet joints and segmental spinal instability following surgery were also evaluated.

Overview of Literature

Previous reports have documented bone regrowth after conventional laminectomy or laminotomy and several factors associated with new bone formation.

Methods

Forty-nine patients who underwent microscopic bilateral decompression via a unilateral approach at L4–5 were reviewed. Primary outcomes included correlations among postoperative bone regrowth, preservation of facet joints, radiographic parameters, and clinical outcomes. Secondary outcomes included comparative analyses of radiographic parameters and clinical outcomes among preoperative diagnoses (lumbar spinal stenosis, degenerative spondylolisthesis, and degenerative lumbar scoliosis).

Results

The average value of bone regrowth at the latest follow-up was significantly higher on the dorsal side of the facet joint (3.4 mm) than on the ventral side (1.3 mm). Percent facet joint preservation was significantly smaller on the approach side (79.2%) than on the contralateral side (95.2%). Bone regrowth showed a significant inverse correlation with age, but no significant correlation was observed with facet joint preservation, gender, postoperative segmental spinal motion, or clinical outcomes. Subanalysis of these data revealed that bone regrowth at the latest follow-up was significantly greater in patients with degenerative lumbar scoliosis than in those with lumbar spinal stenosis. Postoperative segmental spinal motion at L4–L5 did not progress significantly in patients with degenerative spondylolisthesis or degenerative lumbar scoliosis compared with those with lumbar spinal stenosis.

Conclusions

Microscopic bilateral decompression via a unilateral approach prevents postoperative spinal instability because of satisfactory preservation of facet joints, which may be the primary reason for inadequate bone regrowth. Postoperative bone regrowth was not related to clinical outcomes and postoperative segmental spinal instability.

Minimally Invasive Unilateral Laminectomy for Bilateral Decompression

Introduction

Unilateral laminectomy for bilateral decompression (ULBD) is a recently popularized minimally invasive surgical technique for decompression of the spinal canal.

Indications & Contraindications

Step 1 Positioning Incision and Instruments Required

With the patient prone on the spinal table of your choice, use an image intensifier to determine the incision position and then position the retractor of your choice to identify the inferior aspect of the superior lamina.

Step 2 Bone Removal

Begin the laminotomy on the approach side, drilling to identify the ligamentum flavum on the approach side, and remove bone up to the superior attachment of the ligamentum flavum.

Step 3 Undercutting of the Spinous Process

To gain access to the contralateral side of the canal for bilateral decompression, remove enough of the spinous process to gain access to the midline and contralateral ligamentum flavum.

Step 4 Identify the Superior Aspect of the Ligamentum Attachment

The superior aspect of the decompression usually corresponds with the superior ligamentum flavum attachment, except in certain cases such as when a facet joint cyst extends beyond the limits of the ligamentum flavum; removal of the upper limit of the ligamentum flavum provides an important landmark to confirm the superior limit of the decompression.

Step 5 Lateral Recess Decompression on the Ipsilateral Approach Side

Detach the ligamentum flavum from the facet joint on the approach side using a combination of angled curets and Kerrison rongeurs; a partial medial facetectomy, or removal of adequate facet hypertrophy, on the approach side is necessary to expose the traversing nerve root.

Step 6 Decompression of the Contralateral Side of the Canal

Decompression of the thecal sac on the contralateral side of the canal is the potentially dangerous aspect of the procedure, with the highest risk of dural injury and a cerebrospinal fluid leak; thus, create enough room on the ipsilateral side so that instruments can be safely introduced into the canal for the contralateral decompression.

Step 7 Hemostasis

Reducing the paraspinal muscle dissection substantially reduces iatrogenic muscle injury and blood loss, and oozing from the bone removal can be easily controlled with bone wax or a variety of hemostatic agents.

Step 8 Closure

Closure of a unilateral muscle exposure is rapid and the use of wound drainage is very rare, further reducing operative time as well as exposure to complications related to wound drains and subsequent infection risk.

Results

One of us (R.M.) and colleagues⁵ conducted a prospective randomized trial comparing ULBD with open laminectomy for degenerative lumbar spinal stenosis in 54 patients (27 in each arm of the study) treated from 2007 to 2009.

Pitfalls & Challenges

Facet Effusion without Radiographic Instability Has No Effect on the Outcome of Minimally Invasive Decompression Surgery

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

Lumbar segmental instability is a key factor determining whether decompression alone or decompression and fusion surgery is required to treat lumbar spinal stenosis (LSS). Some recent reports have suggested that facet joint effusion is correlated with spinal segmental instability. The aim of this study is to report the effect of facet effusion without radiographic segmental instability on the outcome of less-invasive decompression surgery for LSS.

METHODS

Seventy-nine patients with LSS (32 women, mean age: 69.1 ± 9.1 years) who had no segmental instability on dynamic radiographs before undergoing L4-L5 microsurgical decompression and who were followed for at least 2 years postoperatively were analyzed. They were divided into three groups on the basis of the existence and size of L4-L5 facet effusion using preoperative magnetic resonance imaging: grade 0 had no effusion (n = 31), grade 1 had measurable effusion (n = 35), and grade 2 had large effusion (n = 13). Japanese Orthopedics Association (JOA) score, visual analog scale (VAS), and the Short-Form (SF)-36 scores were recorded preoperatively and 12 and 24 months postoperatively.

RESULTS

JOA score; VAS of low back pain, leg pain, and numbness; and SF-36 (physical component summary and mental component summary) scores did not differ significantly between the three groups in every terms (p = 0.921, 0.996, 0.950, 0.693, 0.374, 0.304, and 0.624, respectively, at final follow-up).

CONCLUSION

In the absence of radiographic instability, facet joint effusion has no effect on the outcome of less-invasive decompression surgery.

Surgical treatment of degenerative spondylolisthesis

Degenerative spondylolisthesis is a common pathology, often causing lumbar canal stenosis. There is, however, no strong consensus regarding the various medical and surgical treatments available. Surgery is indicated mainly for perceived functional impairment; when the indication is accepted, several questions determine the choice of surgical strategy. Improvement in neurological symptoms is one of the main treatment objectives. For this, it is useful to perform radicular decompression. Some authors recommend indirect decompression by interbody fusion (ALIF, TLIF, XLIF), others by means of an interspinous spacer but the most frequent technique is direct posterior decompression. In degenerative spondylolisthesis, functional results seem to be improved by associating stabilization to decompression, to prevent secondary destabilization. The following risk factors for destabilization are recognized: anteroposterior hypermobility, angular hypermobility and large disc height. Two stabilization techniques have been described: "dynamic" stabilization and (more frequently) fusion. Spinal instrumentation is frequently associated to fusion, in which case, it is essential for fusion position and length to take account of pelvic incidence and the patient's overall pattern of balance. Posterolateral fusion may be completed by interbody fusion (PLIF or TLIF). This has the theoretic advantage of increasing graft area and stability, restoring local lordosis and opening the foramina. Surgical treatment of degenerative spondylolisthesis usually consists in posterior release associated to instrumented fusion, but some cases can be more complex. It is essential for treatment planning to take account of the patient's general health status as well as symptomatology and global and segmental alignment.

Lumbar Degenerative Spondylolisthesis: Changes in Surgical Indications and Comparison of Instrumented Fusion With Two Surgical Decompression Procedures

STUDY DESIGN

Single-center retrospective case series.

OBJECTIVE

To compare outcomes of instrumented fusion and two methods of decompression for degenerative spondylolisthesis.

SUMMARY OF BACKGROUND DATA

There is no consensus on the surgical indications or optimum techniques for lumbar degenerative spondylolisthesis.

METHODS

We analyzed the data of 140 patients treated by fusion (n = 80; mean follow-up, 77.9 months) or decompression (n = 60; mean follow-up, 38.0 months) and examined changes in surgical indications over a 12-year period. We compared the outcomes of instrumented fusion with the outcomes of two decompression techniques, the first employing a unilateral approach for bilateral decompression and the second employing a bilateral approach for contralateral decompression, with contralateral foraminal decompression as needed. Postoperative evaluation was made at the final follow-up visit beginning in 2007 by analyzing patient interviews and neurological examination data. We compared results with the Japanese Orthopedic Association symptom score before surgery and at final follow-up.

RESULTS

Surgical indications for fusion narrowed over time, with fusion used less frequently and decompression used more frequently. Similar decreases in clinical symptoms, including low back pain, were achieved with all methods. In the decompression groups, preoperative slip distance and instability, and postoperative slip progression or development of instability, did not correlate significantly with clinical outcome. Slip progression occurred in 8 of 10 levels in patients with preoperative translation ≥5 mm, but these patients showed no increase in instability, defined as translation ≥ 2 mm, at final follow-up.

CONCLUSION

Our findings raise a question about the value of the radiologic criteria for performing fusion used in the late period, namely translation ≥5 mm and/or rotation ≥ 10°. If discogenic pain is excluded, decompression alone may be suitable even for patients with severe low back pain and translation ≥5 mm.

LEVEL OF EVIDENCE

4.

"Slalom": Microsurgical Cross-Over Decompression for Multilevel Degenerative Lumbar Stenosis

Objective. Selective, bilateral multisegmental microsurgical decompression of lumbar spinal canal stenosis through separate, alternating cross-over approaches. Indications. Two-segmental and multisegmental degenerative central and lateral lumbar spinal stenosis. Contraindications. None. Surgical Technique. Minimally invasive, muscle, and facet joint-sparing bilateral decompression of the lumbar spinal canal through 2 or more alternating microsurgical cross-over approaches from one side. Results. From December 2010 until December 2015 we operated on 202 patients with 2 or multisegmental stenosis (115 f; 87 m; average age 69.3 yrs, range 51-91 yrs). All patients were suffering from symptoms typical of a degenerative lumbar spinal stenosis. All patients complained about back pain; however the leg symptoms were dominant in all cases. Per decompressed segment, the average OR time was 36 min and the blood loss 45.7 cc. Patients were mobilized 6 hrs postop and hospitalization averaged 5.9 days. A total of 116/202 patients did not need submuscular drainage. 27/202 patients suffered from a complication (13.4%). Dural tears occurred in 3.5%, an epidural hematoma in 5.5%, a deep wound infection in 1.98%, and a temporary radiculopathy postop in 1.5%. Postop follow-up ranged from 12 to 24 months. There was a significant improvement of EQ 5 D, Oswestry Disability Index (ODI), VAS for Back and Leg Pain, and preoperative standing times and walking distances.

Microsurgical unilateral laminotomy for decompression of lumbar spinal stenosis: long-term results and predictive factors

BACKGROUND

The microsurgical unilateral laminotomy (MUL) technique for bilateral decompression of lumbar spinal stenosis (LSS) is a less destabilizing alternative to laminectomy and leads to good short-term outcomes. However, little is known about the long-term results including predictive factors.

METHODS

Medical records of patients who underwent MUL for LSS decompression between 2005 and 2010 were reviewed, and a questionnaire was distributed to complement the long-term outcome data. The study population consisted of 176 patients including 17 patients with stable grade I spondylolisthesis. Complications and reoperations were meticulously analyzed. Clinical outcome was measured using a modified Prolo scale and was further dichotomized in good vs. poor outcome. Predictive factors were obtained from uni- and multivariate analyses.

RESULTS

The median age of the cohort was 70.0 years and the follow-up 71.7 months. Complications occurred in 5.1 % of the patients. The overall reoperation rate was 17.0 %, including surgery, which was exclusively performed at other levels in 4.0 %. The reoperation rate for fusion was 4.5 %. Good neurogenic claudication outcome faded from 98.3 % at hospital discharge to 47.2 % at 6 years. Multivariate analysis identified previous lumbar operation as a potential independent predictor of a reoperation; potential independent predictors of poor long-term claudication outcome were older age, female gender, higher body mass index (BMI) and tobacco smoking.

CONCLUSIONS

In our experience, the long-term reoperation rate after MUL for LSS is not negligible and higher in previously operated patients. It seems like the good initial clinical results after MUL may fade over time, and several patient-related predictive factors including potentially modifiable obesity and tobacco smoking seem to play an important role.

Factors associated with improvement in sagittal spinal alignment after microendoscopic laminotomy in patients with lumbar spinal canal stenosis

OBJECTIVE Little is known about the relationship between sagittal spinal alignment in patients with lumbar spinal canal stenosis (LSS) and objective findings such as spinopelvic parameters, lumbar back muscle degeneration, and clinical data. The purpose of this study was to identify the preoperative clinical and radiological factors that predict improvement in sagittal spinal alignment after decompressive surgery in patients with LSS. METHODS The records of 61 patients with LSS who underwent microendoscopic laminotomy and had pre- and postoperative clinical data collected were retrospectively reviewed. Spinopelvic parameters, including sagittal vertical axis (SVA), lumbar lordosis (LL), sacral slope, pelvic tilt, and pelvic incidence (PI), were evaluated. On T2-weighted MRI, the cross-sectional area and the percentage of fat infiltration of the paravertebral muscles (PVMs) before surgery were calculated. For patients with preoperative SVA > 40 mm (n = 30), the correlation between SVA improvement and preoperative clinical and radiographic parameters was calculated. RESULTS SVA improvement correlated with preoperative LL (r = -0.39) and PI -LL (r = 0.54). Multiple regression analysis showed that preoperative PI -LL (beta = 0.62; p < 0.01) and symptom duration (beta = -0.40; p < 0.05) were independently associated with SVA improvement. The percentage of fat infiltration of the PVM at L4-5 was significantly greater in patients with preoperative SVA ≥ 40 mm than in those patients with SVA < 40 mm. CONCLUSIONS Preoperative PI -LL and symptom duration were independently associated with SVA improvement in LSS patients with forward-bending posture. PVM degeneration at the lower lumbar level was significantly greater among patients with preoperative SVA ≥ 40 mm than in patients with SVA < 40 mm.

Guideline summary review: An evidence-based clinical guideline for the diagnosis and treatment of degenerative lumbar spondylolisthesis

BACKGROUND CONTEXT

The North American Spine Society's (NASS) Evidence-Based Clinical Guideline for the Diagnosis and Treatment of Degenerative Lumbar Spondylolisthesis features evidence-based recommendations for diagnosing and treating degenerative lumbar spondylolisthesis. The guideline updates the 2008 guideline on this topic and is intended to reflect contemporary treatment concepts for symptomatic degenerative lumbar spondylolisthesis as reflected in the highest quality clinical literature available on this subject as of May 2013. The NASS guideline on this topic is the only guideline on degenerative lumbar spondylolisthesis included in the Agency for Healthcare Research and Quality's National Guideline Clearinghouse (NGC).

PURPOSE

The purpose of this guideline is to provide an evidence-based educational tool to assist spine specialists when making clinical decisions for patients with degenerative lumbar spondylolisthesis. This article provides a brief summary of the evidence-based guideline recommendations for diagnosing and treating patients with this condition.

STUDY DESIGN

A systematic review of clinical studies relevant to degenerative spondylolisthesis was carried out.

METHODS

This NASS spondyolisthesis guideline is the product of the Degenerative Lumbar Spondylolisthesis Work Group of NASS' Evidence-Based Guideline Development Committee. The methods used to develop this guideline are detailed in the complete guideline and technical report available on the NASS website. In brief, a multidisciplinary work group of spine care specialists convened to identify clinical questions to address in the guideline. The literature search strategy was developed in consultation with medical librarians. Upon completion of the systematic literature search, evidence relevant to the clinical questions posed in the guideline was reviewed. Work group members used the NASS evidentiary table templates to summarize study conclusions, identify study strengths and weaknesses, and assign levels of evidence. Work group members participated in webcasts and in-person recommendation meetings to update and formulate evidence-based recommendations and incorporate expert opinion when necessary. The draft guidelines were submitted to an internal peer review process and ultimately approved by the NASS Board of Directors. Upon publication, the Degenerative Lumbar Spondylolisthesis guideline was accepted into the NGC and will be updated approximately every 5 years.

RESULTS

Twenty-seven clinical questions were addressed in this guideline update, including 15 clinical questions from the original guideline and 12 new clinical questions. The respective recommendations were graded by strength of the supporting literature, which was stratified by levels of evidence. Twenty-one new or updated recommendations or consensus statements were issued and 13 recommendations or consensus statements were maintained from the original guideline.

CONCLUSIONS

The clinical guideline was created using the techniques of evidence-based medicine and best available evidence to aid practitioners in the care of patients with degenerative lumbar spondylolisthesis. The entire guideline document, including the evidentiary tables, literature search parameters, literature attrition flow chart, suggestions for future research, and all of the references, is available electronically on the NASS website at https://www.spine.org/Pages/ResearchClinicalCare/QualityImprovement/ClinicalGuidelines.aspx and will remain updated on a timely schedule.

Prognostic Factors of Surgical Outcome after Spinous Process-Splitting Laminectomy for Lumbar Spinal Stenosis

STUDY DESIGN

A retrospective case review.

PURPOSE

To assess the clinical and radiographic outcomes and identify the predictive factors associated with poor clinical outcomes after lumbar spinous process-splitting laminectomy (LSPSL) for lumbar spinal stenosis (LSS).

OVERVIEW OF LITERATURE

LSPSL is an effective surgical treatment for LSS. Special care should be taken in patients with degenerative lumbar scoliosis (DLS).

METHODS

A consecutive retrospective case review of patients undergoing LSPSL for LSS with a minimum 2-year follow-up was performed. Mild DLS and mild degenerative spondylolisthesis (DS) were included in the study. The Japanese Orthopedic Association (JOA) score and recovery rate were reviewed. Poor clinical outcome was defined as a recovery rate <50% using Hirabayashi's method.

RESULTS

A total of 52 patients (mean age, 72 years) met the inclusion criteria and had a mean follow-up of 2.6 years (range, 2-4.5 years). The preoperative diagnosis was LSS in 19, DS in 19, and DLS in 14 cases. The mean JOA score significantly increased from 14.6 to 23.2 at the final follow-up. The overall mean recovery rate was 60.1%. Thirteen patients (25%) were assigned to the poor outcome group. A higher rate of pre-existing DLS was observed in the poor outcome (poor) group (good, 15%; poor, 62%; p=0.003) than in the good outcome (good) group. None of the patient factors examined were associated with a poor outcome. A progression of slippage ≥5 mm was found in 8 of 24 patients (33%) in the DS group. A progression of curvature ≥5° was found in 5 of 14 patients (36%) in the DLS group. The progression of scoliosis and slippage did not influence the clinical outcome.

CONCLUSIONS

The clinical and radiographic outcomes of LSPSL for LSS were favorable. Pre-existing DLS was significantly associated with poor clinical outcome.

UNILATERAL LAMINOTOMY FOR BILATERAL MICRODECOMPRESSION OF STENOSIS OF THE LUMBAR CANAL

With the aging of the world population, the treatment of stenosis of the lumbar canal has become an important issue in addressing degenerative diseases of the spine. The prevalence of this disease tends to increase as the number of surgeries and the impact on health care costs. This paper aims to describe in detail the technique of unilateral laminotomy for bilateral microdecompression (ULBM) of stenosis of the lumbar canal (LSC) and current clinical results, including their advantages, disadvantages and common complications, based on the available literature. Important studies have shown evidence that surgical treatment for LSC is more effective than the conservative, but without evaluating ULBM. Several studies on ULBM have been conducted since the 90s, showing the results of this technique, however, most of these are case series, retrospective studies or cohorts without proper control group or with weak statistical analysis to prove some evidence. A double-blind randomized clinical trial was found, but with short follow-up. We conclude that studies are needed with more solid evidence to prove the effectiveness of ULBM despite the clinical results being similar to those of classical surgery found in the literature.

The influence of preoperative spinal sagittal balance on clinical outcomes after microendoscopic laminotomy in patients with lumbar spinal canal stenosis

OBJECT

More information about the association between preoperative anterior translation of the C-7 plumb line and clinical outcomes after decompression surgery in patients with lumbar spinal canal stenosis (LSS) would help resolve problems for patients with sagittal imbalance. The authors evaluated whether preoperative sagittal alignment of the spine affects low-back pain and clinical outcomes after microendoscopic laminotomy.

METHODS

This study was a retrospective review of prospectively collected surgical data. The study comprised 88 patients with LSS (47 men and 41 women) who ranged in age from 39 to 86 years (mean age 68.7 years). All patients had undergone microendoscopic laminotomy at Osaka City University Graduate School of Medicine from May 2008 through October 2012. The minimum duration of clinical and radiological follow-up was 6 months. All patients were evaluated by Japanese Orthopaedic Association (JOA) and visual analog scale (VAS) scores for low-back pain, leg pain, and leg numbness before and after surgery. The distance between the C-7 plumb line and the posterior corner of the sacrum (sagittal vertical axis [SVA]) was measured on lateral standing radiographs of the entire spine obtained before surgery. Radiological factors and clinical outcomes were compared between patients with a preoperative SVA ≥ 50 mm (forward-bending trunk [F] group) and patients with a preoperative SVA < 50 mm (control [C] group). A total of 35 patients were allocated to the F group (19 male and 16 female) and 53 to the C group (28 male and 25 female).

RESULTS

The mean SVA was 81.0 mm for patients in the F group and 22.0 mm for those in the C group. At final follow-up evaluation, no significant differences between the groups were found for the JOA score improvement ratio (73.3% vs 77.1%) or the VAS score for leg numbness (23.6 vs 24.0 mm); the VAS score for low-back pain was significantly higher for those in the F group (21.1 mm) than for those in the C group (11.0 mm); and the VAS score for leg pain tended to be higher for those in the F group (18.9 ± 29.1 mm) than for those in the C group (9.4 ± 16.0 mm).

CONCLUSIONS

Preoperative alignment of the spine in the sagittal plane did not affect JOA scores after microendoscopic laminotomy in patients with LSS. However, low-back pain was worse for patients with preoperative anterior translation of the C-7 plumb line than for those without.

Development of appropriateness criteria for the surgical treatment of symptomatic lumbar degenerative spondylolisthesis (LDS)

PURPOSE

Spine surgery rates are increasing worldwide. Treatment failures are often attributed to poor patient selection and inappropriate treatment, but for many spinal disorders there is little consensus on the precise indications for surgery. With an aging population, more patients with lumbar degenerative spondylolisthesis (LDS) will present for surgery. The aim of this study was to develop criteria for the appropriateness of surgery in symptomatic LDS.

METHODS

A systematic review was carried out to summarize the current level of evidence for the treatment of LDS. Clinical scenarios were generated comprising combinations of signs and symptoms in LDS and other relevant variables. Based on the systematic review and their own clinical experience, twelve multidisciplinary international experts rated each scenario on a 9-point scale (1 highly inappropriate, 9 highly appropriate) with respect to performing decompression only, fusion, and instrumented fusion. Surgery for each theoretical scenario was classified as appropriate, inappropriate, or uncertain based on the median ratings and disagreement in the ratings.

RESULTS

744 hypothetical scenarios were generated; overall, surgery (of some type) was rated appropriate in 27%, uncertain in 41% and inappropriate in 31%. Frank panel disagreement was low (7% scenarios). Face validity was shown by the logical relationship between each variable's subcategories and the appropriateness ratings, e.g., no/mild disability had a mean appropriateness rating of 2.3 ± 1.5, whereas the rating for moderate disability was 5.0 ± 1.6 and for severe disability, 6.6 ± 1.6. Similarly, the average rating for no/minimal neurological abnormality was 2.3 ± 1.5, increasing to 4.3 ± 2.4 for moderate and 5.9 ± 1.7 for severe abnormality. The three variables most likely (p < 0.0001) to be components of scenarios rated "appropriate" were: severe disability, no yellow flags, and severe neurological deficit.

CONCLUSION

This is the first study to report criteria for determining candidacy for surgery in LDS developed by a multidisciplinary international panel using a validated method (RAM). The panel ratings followed logical clinical rationale, indicating good face validity. The work refines clinical classification and the phenotype of degenerative spondylolisthesis. The predictive validity of the criteria should be evaluated prospectively to examine whether patients treated "appropriately" have better clinical outcomes.

[Selective, microsurgical cross-over decompression of multisegmental degenerative lumbar spinal stenoses: the "Slalom" technique]

OBJECTIVE

Selective, bilateral multisegmental microsurgical decompression of lumbar spinal canal stenosis through separate, alternating cross-over approaches.

INDICATIONS

Two- and multisegmental degenerative central and lateral lumbar spinal stenoses.

CONTRAINDICATIONS

None (however, if stabilization is necessary, the Slalom technique is not possible).

SURGICAL TECHNIQUE

Minimally invasive, muscle-sparing and facet-joint-sparing bilateral decompression of the lumbar spinal canal through 2 or more alternating microsurgical cross-over approaches from one side.

POSTOPERATIVE MANAGEMENT

Early mobilization 4-6 h postoperatively. Soft lumbar brace for 4 weeks (optional).

RESULTS

Between December 2010 and May 2011, the operation was performed in 35 patients (10 women; 25 men; age 71.8 years). The average time of surgery was 42 min/segment, the average blood loss was 20.3 ml/segment. Of the 35 patients, 15 did not required wound drainage. All patients were mobilized without restriction after 4-6 h, hospitalization was 5.2 days. There were 3 intraoperative complications (2 Dura lesions [5.7%] and 1 temporary L5 radiculopathy probably due to swelling of the L5 nerve root [2.8%]). Postoperatively there was a significant improvement in quality of life as measured with EQ 5D and Oswestry Disability Index as well as a significant improvement of walking distance and standing time.

Minimum 3-year outcomes in patients with lumbar spinal stenosis after bilateral microdecompression by unilateral or bilateral laminotomy

Objective

Lumbar spine stenosis (LSS) can result in symptomatic compression of the neural elements, requiring surgical treatment if conservative management fails. Minimally invasive surgery has come to be more commonly used for the treatment of LSS. The current study describes outcomes of bilateral microdecompression by unilateral or bilateral laminotomy (BML) for degenerative LSS after a minimum follow-up period of 3 years and investigates factors that result in a poor outcome.

Methods

Twenty-one patients who were followed-up for at least 3 years were included in this study. For clinical evaluation, the Japanese Orthopedic Association (JOA) scoring system for low back pain was used. The modified grading system of Finneson and Cooper was used for outcome assessment. Radiographic evaluation was also performed for spondylolisthesis, sagittal rotation angle, and disc height.

Results

Twenty-one patients (10 men, 11 women) aged 53-82 years (64.1±8.9 years) were followed-up for a minimum of 3 years (36-69 months). During follow-up, two patients underwent reoperation. Average preoperative JOA score and clinical symptoms, except persistent low back pain, improved significantly at the latest follow-up. There were no significant differences in radiological findings preoperatively and postoperatively. Thirteen patients (61.9%) had excellent to fair outcomes.

Conclusion

BML resulted in a favorable and persistent outcome for patients with degenerative LSS without radiological instability over a mid-term follow-up period. Persistent low back pain unrelated to postoperative instability adversely affects mid-term outcomes.

Clinical characteristics of intraspinal facet cysts following microsurgical bilateral decompression via a unilateral approach for treatment of degenerative lumbar disease

PURPOSE

Primary intraspinal facet cysts in the lumbar spine are uncommon, but it is unclear whether cyst incidence increases following decompression surgery and if these cysts negatively impact clinical outcome. We examined the prevalence, clinical characteristics, and the risk factors associated with intraspinal facet cysts after microsurgical bilateral decompression via a unilateral approach (MBDU).

METHODS

We studied 230 patients treated using MBDU for lumbar degenerative disease (133 men and 97 women; mean age 70.3 years). Clinical status, as assessed by the Japanese Orthopedic Association (JOA) score and findings on X-ray and magnetic resonance images, was evaluated prior to surgery and at both 3 months and 1 year after surgery. The prevalence of intraspinal facet cysts was determined and preoperative risk factors were defined by comparing presurgical findings with clinical outcomes.

RESULTS

Thirty-eight patients (16.5%) developed intraspinal facet cysts within 1 year postoperatively, and 24 exhibited cysts within 3 months. In 10 patients, the cysts resolved spontaneously 1 year postoperatively. In total, 28 patients (12.2%) had facet cysts 1 year postoperatively. The mean JOA score of patients with cysts 1 year postoperatively was significantly lower than that of patients without cysts. This poor clinical outcome resulted from low back pain that was not improved by conservative treatment. Most cases with spontaneous cyst disappearance were symptom-free 1 year later. The preoperative risk factors for postoperative intraspinal facet cyst formation were instability (OR 2.47, P = 0.26), scoliotic disc wedging (OR 2.23, P = 0.048), and sagittal imbalance (OR 2.22, P = 0.045).

CONCLUSIONS

Postoperative intraspinal facet cyst formation is a common cause of poor clinical outcome in patients treated using MBDU.

Degenerative lumbar spinal stenosis: evaluation and management

Degenerative lumbar spinal stenosis is caused by mechanical factors and/or biochemical alterations within the intervertebral disk that lead to disk space collapse, facet joint hypertrophy, soft-tissue infolding, and osteophyte formation, which narrows the space available for the thecal sac and exiting nerve roots. The clinical consequence of this compression is neurogenic claudication and varying degrees of leg and back pain. Degenerative lumbar spinal stenosis is a major cause of pain and impaired quality of life in the elderly. The natural history of this condition varies; however, it has not been shown to worsen progressively. Nonsurgical management consists of nonsteroidal anti-inflammatory drugs, physical therapy, and epidural steroid injections. If nonsurgical management is unsuccessful and neurologic decline persists or progresses, surgical treatment, most commonly laminectomy, is indicated. Recent prospective randomized studies have demonstrated that surgery is superior to nonsurgical management in terms of controlling pain and improving function in patients with lumbar spinal stenosis.