A review: Reduced reoperation rate for multilevel lumbar laminectomies with noninstrumented versus instrumented fusions

Relationship between lumbar lordosis, pelvic parameters, PI-LL mismatch and outcome after short fusion surgery for lumbar degenerative disease. Literature review, rational and presentation of public study protocol: RELApSE study (registry for evaluation of lumbar artrodesis sagittal alignEment)

Background

Vertebral arthrodesis for degenerative pathology of the lumbar spine still remains burdened by clinical problems with significant negative results. The introduction of the sagittal balance assessment with the evaluation of the meaning of pelvic parameters and spinopelvic (PI-LL) mismatch offered new evaluation criteria for this widespread pathology, but there is a lack of consistent evidence on long-term outcome.

Methods

The authors performed an extensive systematic review of literature, with the aim to identify all potentially relevant studies about the role and usefulness of the restoration or the assessment of Sagittal balance in lumbar degenerative disease. They present the study protocol RELApSE (NCT05448092 ID) and discuss the rationale through a comprehensive literature review.

Results

From the 237 papers on this topic, a total of 176 articles were selected in this review. The analysis of these literature data shows sparse and variable evidence. There are no observations or guidelines about the value of lordosis restoration or PI-LL mismatch. Most of the works in the literature are retrospective, monocentric, based on small populations, and often address the topic evaluation partially.

Conclusions

The RELApSE study is based on the possibility of comparing a heterogeneous population by pathology and different surgical technical options on some homogeneous clinical and anatomic-radiological measures aiming to understanding the value that global lumbar and segmental lordosis, distribution of lordosis, pelvic tilt, and PI-LL mismatch may have on clinical outcome in lumbar degenerative pathology and on the occurrence of adjacent segment disease.

5-Year Revision Rates After Elective Multilevel Lumbar/Thoracolumbar Instrumented Fusions in Older Patients: An Analysis of State Databases

OBJECTIVE

The purpose of this study wasto evaluate cause-specific 5-year revision rates and risk factors for revision after elective multilevel lumbar instrumented fusion in older patients.

METHODS

Older patients (>60 years) who underwent elective multilevel (3+) lumbar instrumented fusions were identified in Healthcare Cost and Utilization Project state inpatient databases and followed for 5 years for revision operations because of mechanical failure, degenerative disease (DD), infection, postlaminectomy syndrome, and stenosis. Cox proportional hazards multivariate analyses were conducted to determine risk factors associated with revision for each diagnostic cause.

RESULTS

The cohort included 5,636 patients (female-3,285; average age-71.6 years). Most of the operations were 3 to 7 levels (97.4%), and the mean length of stay was 5.4 days. The overall 5-year revision rate was 16.5% with predominant etiologies of DD (50.7%), mechanical failure (32.2%), and stenosis (8.0%). The revision procedure at the index operation was associated with an increased revision risk for DD (hazards ratio [HR] = 1.59, 95% confidence interval [CI], 1.29 to 1.98, P < 0.001) and mechanical failure (HR = 1.56, 95% CI, 1.19 to 2.04, P = 0.020). Male sex was associated with a significantly reduced revision risk for DD (HR = 0.75, 95% CI, 0.62 to 0.91, P = 0.04). Age, race, and number of comorbidities had no notable effect on the overall or cause-specific risk of revision.

DISCUSSION

In this large database analysis, DD and mechanical failure were the most common etiologies comprising a 5-year revision rate of 16.5% after elective multilevel lumbar instrumented fusion in older patients. Revision operations and female patients carried the strongest risks for revision.

Better Functional Recovery After Single-Level Compared With Two-Level Posterolateral Lumbar Fusion

Background

Multiple studies describe the outcomes of patients undergoing single-level and multilevel posterolateral lumbar fusion (PLF). However, a comparison of outcomes between single-level and two-level PLF is lacking. The aim of this prospective cohort study was to compare outcomes between single-level and two-level instrumented PLF.

Methods

A total of 42 patients were enrolled at nine US centers between October 2015 and June 2017. Data included radiologic outcomes, visual analog scale (VAS) Back and Leg Pain, disability per the Oswestry Disability Index (ODI), and health-related quality of life (QoL) per 36-Item Short Form Survey version 2.0 (SF-36v2) at six weeks and three, six, 12, and 24 months.

Results

Twelve-month and 24-month follow-ups were completed by 38 (90.5%) and 32 (76.2%) subjects, respectively. The average age was 67 years, and 54.8% were female. Twenty-six received single-level PLF, and 16 received two-level PLF. In the single-level group, there was one reoperation, two postoperative infections, and one dural tear. In the two-level group, there was one postoperative infection. The surgeon computed tomography (CT)-based evaluation of fusion rate was 67.6% (25/37) at 12-month follow-up and 94.1% (32/34) at 24-month follow-up. The third-party evaluation of fusion rate was 52.8% (19/36) at six months, 81.1% (30/37) at 12 months, and 86.5% (32/37) at 24 months. There was a tendency toward a higher fusion rate in single-level compared with two-level PLF. The ODI, SF-36v2 Mental Component Score (MCS), and VAS Back Pain and Leg Pain outcomes improved by the first follow-up visit in both the single-level and two-level groups. Improvement in the ODI was 5.86 (95% confidence interval (CI): 0.03-11.69) points greater in the single-level group compared with the two-level group.

Conclusions

Compared with the two-level PLF subjects, single-level PLF subjects had better functional outcomes and reported higher satisfaction with the outcome of surgery but showed similar fusion, pain, and generic health-related quality of life outcomes. Both single-level and two-level PLF subjects demonstrated high fusion rates in association with improvements in pain, functional, and quality of life outcomes, as well as high satisfaction levels.

Biomechanical feasibility of semi-rigid stabilization and semi-rigid lumbar interbody fusion: a finite element study

BACKGROUND

Semi-rigid lumbar fusion offers a compromise between pedicle screw-based rigid fixation and non-instrumented lumbar fusion. However, the use of semi-rigid interspinous stabilization (SIS) with interspinous spacer and ligamentoplasty and semi-rigid posterior instrumentation (SPI) to assist interbody cage as fusion constructs remained controversial. The purpose of this study is to investigate the biomechanical properties of semi-rigidly stabilized lumbar fusion using SIS or SPI and their effect on adjacent levels using finite element (FE) method.

METHOD

Eight FE models were constructed to simulate the lumbosacral spine. In the non-fusion constructs, semi-rigid stabilization with (i) semi-rigid interspinous spacer and artificial ligaments (PD-SIS), and (ii) PI with semi-rigid rods were simulated (PD + SPI). For fusion constructs, the spinal models were implanted with (iii) PEEK cage only (Cage), (iv) PEEK cage and SIS (Cage+SIS), (v) PEEK cage and SPI (Cage+SPI), (vi) PEEK cage and rigid PI (Cage+PI).

RESULT

The comparison of flexion-extension range of motion (ROM) in the operated level showed the difference between Cage+SIS, Cage+SPI, and Cage+PI was less than 0.05 degree. In axial rotation, ROM of Cage+SIS were greater than Cage+PI by 0.81 degree. In the infrajacent level, while Cage+PI increased the ROM by 24.1, 27,7, 25.9, and 10.3% and Cage+SPI increased the ROM by 26.1, 30.0, 27.1, and 10.8% in flexion, extension, lateral bending and axial rotation respectively, Cage+SIS only increased the ROM by 3.6, 2.8, and 11.2% in flexion, extension, and lateral bending and reduced the ROM by 1.5% in axial rotation. The comparison of the von Mises stress showed that SIS reduced the adjacent IVD stress by 9.0%. The simulation of the strain energy showed a difference between constructs less than 7.9%, but all constructs increased the strain energy in the infradjacent level.

CONCLUSION

FE simulation showed semi-rigid fusion constructs including Cage+SIS and Cage+SPI can provide sufficient stabilization and flexion-extension ROM reduction at the fusion level. In addition, SIS-assisted fusion resulted in less hypermobility and less von Mises stress in the adjacent levels. However, SIS-assisted fusion had a disadvantage of less ROM reduction in lateral bending and axial rotation. Further clinical studies are warranted to investigate the clinical efficacy and safety of semi-rigid fusions.

Patients Undergoing 3-Level-or-Greater Decompression-Only Surgery for Lumbar Spinal Stenosis Have Similar Outcomes to Those Undergoing Single-Level Surgery at 2 Years

BACKGROUND

Stability following multilevel decompressive laminectomy without fusion has been debated using in vitro biomechanical and radiographic models. However, there is a lack of information regarding clinical outcomes for these patients. The aim of the present study was to determine the association between clinical outcomes and number of levels decompressed via laminectomy for treatment of lumbar spinal stenosis.

METHODS

We performed a retrospective cohort analysis of patients who underwent a primary lumbar laminectomy between 2009 and 2015 by senior orthopedic spine surgeons for lumbar spinal stenosis. Patients were divided into 2 groups based on the number of decompression levels: single level or 3 or more levels. Patient-reported outcomes were obtained in the form of Oswestry Disability Index (ODI) scores, visual analog scale (VAS) scores for the back and leg, 12-Item Short Form Mental and Physical Survey scores, and Veterans Rand 12-Item Health Mental and Physical Survey scores.

RESULTS

Overall, 138 consecutive patients were assessed, of which 106 underwent a single-level and 32 underwent a 3-or-more-level laminectomy. Average follow-up was 24.2 months. There were no significant differences in the preoperative VAS back, VAS leg, or ODI scores between the single-level laminectomy and 3-or-more-level laminectomy groups. Both groups of patients experienced significant improvements in these clinical outcomes postoperatively with no clinically significant difference in the degree of improvement. Reoperation rates were low and similar between the 2 groups.

CONCLUSIONS

Patients undergoing decompression of 3 or more levels present with similar postoperative outcomes to those who undergo a single-level decompression for lumbar spinal stenosis. Under specific clinical and radiographic criteria, a multilevel decompression of 3 or more levels may be a safe and effective procedure with acceptable outcomes at 2 years after surgery.

LEVEL OF EVIDENCE

3.

Lumbar Fusion With Polyetheretherketone Rods Use for Patients With Degenerative Disease

Introduction

Polyetheretherketone (PEEK) rods for lumbar fusion have been available since 2007. However, literature about their utility is sparse and of mixed outcomes.

Methods

A retrospective review of PEEK rod lumbar fusion cases was performed. Data were analyzed from 108 patients of the senior author Donald Ross who underwent PEEK lumbar fusion.

Results

There were 97 single and 11 2-level fusions. Rates of tobacco use, diabetes mellitus, low bone density, depression, and immunosuppression were 23.1%, 24.1%, 14.8%, 32.4%, and 6.5%, respectively. In the study population, the mean age was 60.2 years, body mass index was 30.1, and there was a mean 31.3 months for follow-up. There were no wound infections or new neurologic deficits. Of 81 patients with > 11 months of follow-up, 70 (86.4%) had an arthrodesis, 8 (9.9%) had no arthrodesis, and 3 (3.7%) were indeterminate. No patients had revision fusion surgery and 2 patients had adjacent level fusions at 27 and 60 months. One patient had an adjacent segment laminectomy at 18 months and one a foraminotomy at 89 months, resulting in a 3.7% adjacent segment surgery rate. Mean preoperative Short Form-36 (SF-36) physical functioning (PF) score and Oswestry Disability Index (ODI) score were 28.9 and 24.8, respectively. Mean SF-36 PF postoperative score at 1 and 2 years were 59.3 and 65, respectively. Mean ODI postoperative score at 1 year was 14.5.

Conclusions

In a large patient cohort lumbar fusion with PEEK rods can be undertaken with low complication rates, satisfactory clinical improvements, low rates of hardware failure or need for revision surgery. Longer follow-up is needed to confirm findings.

Noninstrumented Lumbar Fusion with Bone Morphogenetic Proteins for Spinal Stenosis with Spondylolisthesis in the Elderly

OBJECTIVE

This study examined the use of noninstrumented posterolateral lumbar fusion with bone morphogenetic protein (BMP) and compared its effectiveness with that of instrumented fusion for the treatment of lumbar spinal stenosis (LSS) with spondylolisthesis in elderly patients.

METHODS

This study was a retrospective review of 93 patients treated in a single-surgeon neurosurgical private practice over a 15-year period. Fifty-nine patients over the age of 65 who underwent noninstrumented posterolateral fusion with rhBMP-2 (Infuse) for LSS with spondylolisthesis were compared with 34 patients who underwent instrumented fusion without rhBMP-2. Outcomes in terms of reoperation rate, pain improvement, Oswestry Disability Index (ODI) score, and number of extra follow-up visits due to persistent problems were characterized by the use of t tests and χ² tests.

RESULTS

The reoperation rate in the noninstrumented rhBMP-2 fusion group was significantly lower than in the instrumented fusion group (17.6% vs. 3.4%, P = 0.048). The mean pain improvement was significantly higher in the noninstrumented rhBMP-2 group at 3 months (8.1 vs. 6.0, P < 0.001, 95% confidence interval [CI] 1.2 to 3.0) and at 1 year (7.25 vs. 5.6, P = 0.030, 95% CI 0.3 to 3.1). The ODI score improvement was significantly higher in the noninstrumented rhBMP-2 group (51 vs. 42.8, P < 0.001, 95% CI 4.7 to 11.6). The mean number of additional follow-up visits per patient was significantly lower in the noninstrumented rhBMP-2 group (0.068 vs. 1.23, P < 0.001, 95% CI 0.59 to 1.75).

CONCLUSION

Noninstrumented posterolateral lumbar fusion with rhBMP-2 in elderly patients with LSS and spondylolisthesis is a viable alternative to instrumented fusion based on clinical outcomes measured in this study.