Radiographic Classification for Degenerative Spondylolisthesis of the Lumbar Spine Based on Sagittal Balance: A Reliability Study

Lumbar degenerative spondylolisthesis: role of sagittal alignment

PURPOSE

To evaluate the sagittal alignment of the lumbar spine in patients with degenerative spondylolisthesis at the L4-5 level.

METHODS

Patients with untreated degenerative spondylolisthesis at L4-5 were retrospectively identified from the clinical practice of spine surgeons at an academic medical center. All patients had standing X-rays that were reviewed by the senior surgeon to confirm the presence of degenerative spondylolisthesis at L4-5. Radiographs were analyzed for the following: lumbar lordosis (LL), lower lumbar lordosis (L4-S1; LLL), L5-S1 lordosis, pelvic incidence (PI), and pelvic tilt (PT). From these measurements, lumbar distribution index (LLL/LL × 100; LDI), ideal lumbar lordosis (PI × 0.62 + 29; ILL), PI-LL mismatch, and relative lumbar lordosis (LL-ILL; RLL) were calculated. These parameters were used to evaluate the sagittal alignment of the lumbar spine. Normal alignment was defined based on previous studies and clinical experience.

RESULTS

117 participants met inclusion criteria, with an average age of 67.2 years. The majority of the cohort demonstrated hypolordotic sagittal alignment of the L5-S1 segment when assessed in relation to ILL, PI, and LL (73.5%, 61.5%, and 50.4% respectively). Evaluation of the lower lumbar spine (L4-S1) demonstrated normal sagittal alignment when evaluated via LDI and LLL (65%, 52.1%, respectively), suggesting the presence of compensatory hyperextension at L4-5 in response to the L5-S1 hypolordosis. Consequently, normal sagittal alignment of the regional lumbar spine was maintained when evaluated using LL, PI-LL mismatch, and RLL (51.3%, 47%, and 62.4% respectively).

CONCLUSIONS

This study demonstrates that there is a high incidence of relative hypolordosis at the L5-S1 level among patients who present with degenerative spondylolisthesis at L4-5. The L5-S1 hypolordosis is associated with L4-5 hyperlordosis, such that the lower lumbar lordosis (L4-S1; LLL) and regional lumbar lordosis (LL) are still within normal range. It is probable that L5-S1 hypolordosis was the initial pathologic event that incited compensatory L4-5 hyperlordosis, which in turn may have led to facet degeneration and laxity, and eventually to development of spondylolisthesis.

Surgical versus nonsurgical management of lumbar degenerative spondylolisthesis based on spinal canal cross-sectional area

Disability and pain associated with lumbar degenerative spondylolisthesis (LDS) result in a significant burden on both the healthcare costs and patients' quality of life. Currently, there exists controversy regarding employment of either nonsurgical management (NSM) or surgical management (SM) in a clinical setting. Spinal canal cross-sectional area (SCA) has been an important morphological parameter for the analysis of LDS. However, there is lack of research about the comparative value of NSM and SM according to SCA. Moreover, previous research have not yet evaluated the clinical most suitable cutoff values of SCA. The objective of this research was to evaluate the effective of NSM and SM for LDS using SCA as an objective morphological parameter. The axial T2 magnetic resonance imaging images were obtained from each patient. We collected SCA samples from 149 patients with LDS. 72 patients underwent SM and the rest did NSM. We measured SCA at the L4/5 LDS on magnetic resonance imaging using a picture archiving and communications system. We measured SCA at the intervertebral disk posterior border, turning down to reach the facet joint side on the opposite edge at the L4/5 level. The average SCA value was 114.34 ± 48.11 mm2 in the NSM group and 69.88 ± 27.87 mm2 in the SM group. Therefore, the SM group had considerably lower SCA (P < .001). In view of the effectiveness of SCA as a prediction factor of surgical option, Receiver Operating Characteristic curve analysis show the optimal cutoff value for SCA as 83.21 mm2, with 70.8% sensitivity, 71.4% specificity, and an area under the curve of 0.80 (95% CI, 0.73-0.87). The narrower the SCA, the higher the probability of SM. Thus, it is proposed that to evaluate surgical decision making, the pain physician should carefully inspect the SCA.

A Review of the Main Classifications of Lumbar Spondylolisthesis

OBJECTIVE

This study was conducted to review the main classifications and to present author's recommendations.

METHODS

Review of English language medical literature.

RESULTS

In recent decades, classification systems of lumbar spondylolisthesis have been proposed based on many factors, from essential causes to combinations of imaging features and clinical manifestations; the latter type of system is more clinically practical. We have systematically listed the main types of classification systems in chronological order to make it easier for clinicians to find the type of diagnosis and treatment suitable for their patients and develop an appropriate treatment plan.

CONCLUSIONS

Classification systems for lumbar spondylolisthesis have been proposed that have been based on the study of the essential causes or the combination of imaging features and clinical manifestations; the latter type of system is more clinically practical. We still have much work to do in exploring a more applicable classification of lumbar spondylolisthesis.

Degenerative Spondylolisthesis: When to Fuse and When Not to? A New Scoring System

STUDY DESIGN

A prospective cohort.

OBJECTIVE

The objective of this study was to develop a scoring system for lumbar degenerative spondylolisthesis (LDS) that would guide decision-making.

BACKGROUND

The management protocol for LDS has been under debate, with no guidelines. Most studies oversimplify LDS as a homogenous entity.

MATERIALS AND METHODS

A retrospective analysis of 131 patients who underwent surgery for LDS between July 2007 and October 2011 with a minimum follow-up of 3 years was carried out on the basis of clinical, radiologic, and technical factors. A scoring system was conceptualized. Clinical: back pain score-2, age younger than 70 years-1, high-demand activity-1. Radiologic: segmental kyphosis-1.5, segmental dynamic translation-1, disk height >50% of adjacent level-1, facet effusion-1, sagittal facet-orientation-1. Technical: feasibility to decompress without causing instability-1.5. Its reliability was ascertained by a univariate analysis. The benchmark was set at 5.5 according to the Youden Index. This was followed by a prospective study for reliability analysis between November 2011 and January 2017 of 52 patients who underwent stand-alone decompression in LDS with a minimum follow-up of 24 months. Outcomes were evaluated using the Oswestry Disability Index and the Visual Analog Scale. Interobserver variability was determined. None of the patients in the retrospective or prospective group had undergone any lumbar surgery previously.

RESULTS

The mean Oswestry Disability Index and Visual Analog Scale of both the groups in the retrospective and the stand-alone decompression groups in prospective studies showed significant improvement. The interobserver reliability was high, with a κ value of 0.847.

CONCLUSIONS

The proposed scoring system helps view LDS as a heterogenous condition and assists in tailoring treatment for individual patients. For a select subgroup of patients with LDS, minimally invasive decompression (unilateral laminotomy and bilateral decompression using a minimally invasive surgery tubular retractor system) without fusion is adequate.

LEVEL OF EVIDENCE

Level III.

The Therapeutic Evaluation of Spinal Canal Decompression by Using the TBEIS Technique in the Treatment of Lumbar Spinal Stenosis

Objective

To evaluate the clinical efficacy of the percutaneous endoscopic Transforaminal Broad Easy Immediate Surgery (TBEIS) technology in elderly patients with lumbar spinal stenosis (LSS).

Methods

From February 2016 to May 2018, 35 elderly patients with LSS were treated with the TBEIS technique. There were 23 males and 12 females, aged from 53 to 72 years with a median age of 63.1 years. Preoperative, 1 day, and 1 and 12 months postoperative visual analogue scale (VAS) scores and Oswestry Disability Index (ODI) were statistically analyzed. The modified MacNab criterion was used to assess the clinical effects. The radiological outcomes were evaluated by X-ray and computed tomography (CT).

Results

All of the operations were successful. The operative time ranged from 120 to 170 min with a median time of 148 min. All of the patients were followed up for 12 to 38 months with a median follow-up of 18 months. Preoperative, 1 day, and 1 and 12 months postoperative VAS leg scores were 6.91 ± 0.98, 1.69 ± 0.68, 1.23 ± 0.59, and 0.91 ± 0.61, respectively, and the VAS back scores improved from 4.51 ± 0.82 to 0.66 ± 0.68. The ODI scores were 63.82 ± 7.59, 38.79 ± 6.36, 24.79 ± 3.90, and 11.33 ± 3.92, respectively. Postoperative scores of VAS and ODI were obviously improved (P < 0.01). According to the modified MacNab criteria used to evaluate the clinical effects, 11 cases achieved excellent results, 18 cases achieved good results, 4 cases achieved fair results, and 2 cases achieved poor results. There were no neurovascular injury and other complications.

Conclusions

Treatment of LSS in the elderly patients by the TBEIS technology has good clinical efficacy, and the technique is safe and minimally invasive.

In Degenerative Spondylolisthesis, Unilateral Laminotomy for Bilateral Decompression Leads to Less Reoperations at 5 Years When Compared to Posterior Decompression With Instrumented Fusion: A Propensity-matched Retrospective Analysis

STUDY DESIGN

Multicenter retrospective cohort study.

OBJECTIVE

The aim of this study was to compare reoperation rates at 5-year follow-up of unilateral laminotomy for bilateral decompression (ULBD) versus posterior decompression with instrumented fusion (Fusion) for patients with low-grade degenerative spondylolisthesis (DS) with lumbar spinal stenosis (LSS) in a multicenter database.

SUMMARY OF BACKGROUND DATA

Controversy exists regarding whether fusion should be used to augment decompression surgery in patients with LSS with DS. For years, the standard has been fusion with standard laminectomy to prevent postoperative instability. However, this strategy is not supported by Level 1 evidence. Instability and reoperations may be reduced or prevented using less invasive decompression techniques.

METHODS

We identified 164 patients with DS and LSS who underwent ULBD between January 2007 and December 2011 in a multicenter database. These patients were propensity score-matched on age, sex, race, and smoking status with patients who underwent Fusion (n = 437). Each patient required a minimum of 5-year follow-up. The primary outcome was 5-year reoperation. Secondary outcome measures included postoperative complication rates, blood loss during surgery, and length of stay. Logistic regression models were used to estimate the odds ratio of the 5-year reoperation rate between the two surgical groups.

RESULTS

The reoperation rate at 5-year follow-up was 10.4% in the ULBD group and 17.2% in the Fusion group. ULBD reoperations were more frequent at the index surgical level; Fusion reoperations were more common at an adjacent level. The two types of operations had similar postoperative complication rates, and both groups tended to have fusion reoperations.

CONCLUSION

For patients with stable DS and LSS, ULBD is a viable, durable option compared to fusion with decreased blood loss and length stay, as well as a lower reoperation rate at 5-year follow-up. Further prospective studies are required to determine the optimal clinical scenario for ULBD in the setting of DS.

LEVEL OF EVIDENCE

3.

Association Between Irregular Alteration of Facet Orientation and Degenerative Lumbar Spondylolisthesis

BACKGROUND

Numerous studies have reported that irregular alteration of facet orientation (IAFO) is associated with lumbar disc herniation (LDH) in adolescents. The present study investigated the association between IAFO and degenerative lumbar spondylolisthesis (DLS) at the L4-5 segment.

METHODS

Forty-two adults with DLS were enrolled in this study. Facet angles were measured in the bone window of the computed tomography scan. Large-small-large (LSL) was defined as a type of IAFO that includes the angle of facet joints at L4-5, which is smaller than that in L3-4 and L5-S1 segments. Fifty subjects with LDH at L4-5 served as controls. Data were analyzed using logistic regression analysis.

RESULTS

In the 42 patients and 50 controls, the facet angle was measured at 276 levers from L3-4 to L5-S1. The mean included angles of L3-4, L4-5, and L5-S1 were 71.5 ± 19.97°, 51.79 ± 21.43°, and 102.89 ± 20.37°, respectively, in the DLS group and 77.48 ± 17.24°, 91.00 ± 17.24, and 102.94 ± 19.75°, respectively, in the control group. LSL was detected in 38 of 42 subjects (90.5%) in the DLS group, compared with 9 of 50 (18.0%) in the controls. The sagittal orientation facet joint in L4-5 was associated with DLS (odds ratio [OR], 26.24; 95% confidence interval [CI], 13.30-155.35; P = 0.000). The facet in L3-4 with a more coronal orientation than that in L4-5 was also correlated with DLS (OR, 33.68; 95% CI, 9.86-115.06; P = 0.000). There was no correlation between the facet in L5-S1 and DLS in L4-5 (P = 0.999), but there was a strong relationship between LSL in L3-5 and DLS in L4-5 (OR, 43.278; 95% CI, 12.303-152.232; P = 0.000).

CONCLUSIONS

The data presented here demonstrate that LSL, which is an irregular alteration of facet joint orientation, is associated with the degenerative lumbar spondylolisthesis at L4-5.