Lumbar spinal degenerative "microinstability": hype or hope? Proposal of a new classification to detect it and to assess surgical treatment

Analysis of Chronic Low Back Pain Caused by Lumbar Microinstability After Percutaneous Endoscopic Transforaminal Discectomy: A Retrospective Study

Objective

Chronic low back pain (CLBP) after percutaneous endoscopic transforaminal discectomy (PTED) surgery may be caused by preoperative lumbar microinstability (MI). However, there is a paucity of research on the relationship between lumbar microinstability and chronic low back pain. The purpose of this article is to assess the preoperative radiographic characteristics of patients and evaluate the effects of lumbar microinstability on patient-reported outcomes among single-level lumbar disc herniation (LDH) patients who underwent PTED.

Methods

This study retrospectively reviewed the radiographic characteristics of a consecutive series of 127 patients with low back pain and leg pain caused by single-level LDH underwent PTED from August 2018 to March 2021. They were divided into three groups according to the radiographic parameters: the stable group (Group S), the dysfunctional group (Group D), and the microinstability group (Group M). The visual analogue scale (VAS) scores for leg and low back pain and Oswestry Disability Index (ODI) were evaluated preoperatively and postoperatively. Logistic regression analysis was used to identify independent risk factors for CLBP.

Results

Compared with Group D and Group S, Group M had the highest ODI scores (P < 0.01) and VAS scores (low back pain) (P < 0.01) after 1 year, while there were no significant differences in the VAS scores for leg pain at different time points after surgery (P > 0.05). In addition, the logistic regression analysis results regarding CLBP revealed that muscle fatty degeneration on MRI (95% CI, 1.20-8.51, P = 0.02), and facet tropism (95% CI, 1.39 -11.37, P = 0.01) may be independent risk factors.

Conclusion

Patients with lumbar microinstability may have CLBP after PTED, so patients with lumbar microinstability may need to take internal fixation surgery to solve their symptoms.

Radiographic analysis of dynamic lumbar motion during the five-repetition sit-to-stand test in degenerative lumbar spondylolisthesis

Background

To investigate the mechanisms of low back pain triggered by the five-repetition sit-to-stand test (5R-STS test) in degenerative lumbar spondylolisthesis (DLS) from radiographic perspective, as well as to determine the most useful diagnostic modalities in the evaluation of segmental instability.

Methods

We retrospectively performed a study of 78 patients (23 men and 55 women) with symptomatic DLS at L4/5 in our institution between April 2020 and December 2021. Each patient was assessed by using the 5R-STS test and received a series of radiographs including the upright standing, normal sitting, standing flexion–extension radiographs, and supine sagittal MR images. Enrolled patients were divided into two groups based on the 5R-STS test score: severe group and mild group. Translational and angular motion was determined by comparing normal sitting radiograph (N) with upright standing radiograph (U) (Combined, NU), flexion/extension radiographs (FE) as well as normal sitting radiograph (N) with a supine sagittal MR image (sMR) (Combined, N-sMR).

Results

Overall, 78 patients were enrolled, and there were 31(39.7%) patients in group S and 47(60.3%) patients in group M, with an average age of 60.7 ± 8.4 years. The normal sitting radiograph demonstrated the maximum slip percentage (SP) and the highest kyphotic angle both in group S and group M. Compared with group M, group S revealed significantly higher SP in the normal sitting position (24.1 vs 19.6; p = 0.002). The lumbar slip angular in group S with a sitting position was significantly higher than that in group M (-5.2 vs -1.3; p < 0.001). All patients in group S had objective functional impairment (OFI) and 28 patients of them were diagnosed with lumbar instability by using the combination of normal sitting radiograph (N) and supine sagittal MR image (sMR) (Combined, N-sMR).

Conclusion

DLS patients with positive sign of the 5R-STS test is a distinct subgroup associated with lumbar instability. The modality of the combination of normal sitting radiograph (N) and supine sagittal MR image (sMR) had a significant advantage in terms of the ability to identify segmental instability.

The Effectiveness of Radiofrequency Ablation of Medial Branch Nerves for Chronic Lumbar Facet Joint Syndrome in Patients Selected by Guideline-Concordant Dual Comparative Medial Branch Blocks

OBJECTIVES

Although the effectiveness of lumbar medial branch radiofrequency ablation (RFA) for the treatment of zygapophyseal joint (z-joint)-mediated low back pain has been characterized, few studies have described outcomes in patients selected using a guideline-concordant paradigm of ≥80% pain relief with dual comparative medial branch blocks (MBBs). We investigated long-term treatment outcomes of patients selected according to this paradigm.

DESIGN

Cross-sectional cohort study.

METHODS

The medical records of 111 consecutive patients were reviewed; 85 met inclusion criteria. A standardized telephone survey was used to capture current numerical rating scale (NRS) and Patient Global Impression of Change (PGIC) scores. The primary outcome was the proportion of patients reporting ≥50% reduction of index pain. Binary logistic regression analysis was performed to explore associations between the primary outcome and covariates, including age, duration of pain, presence of scoliosis, degenerative spondylolisthesis, and >75% disc height loss.

RESULTS

At six to 12, 12-24, and >24 months, 63.2% (95% confidence interval [CI] = 41-85%), 65.6% (95% CI = 49-82%), and 44.1% (95% CI = 27-61%) of patients reported a ≥50% pain reduction (P = 0.170), respectively. At a minimum of six months, 70.6% of patients reported a pain reduction of two or more points (minimally clinically important change), and 54.1% reported a PGIC score consistent with "much improved" or better. Older age and a smaller Cobb angle were associated with a ≥50% pain reduction (P < 0.05).

CONCLUSION

Lumbar medial branch RFA is an effective, durable treatment for a significant proportion of patients with recalcitrant lumbar z-joint pain when candidacy is determined by the guideline-concordant paradigm of ≥80% pain relief with dual comparative MBBs.

Image-guided percutaneous mechanical disc decompression for herniated discs: a technical note

Interventional radiology plays a key role in the treatment of symptomatic herniations of intervertebral discs. Through image-guided techniques, it is possible to use minimally invasive procedures with a percutaneous approach that are usually proposed before classic surgery. Thanks to imaging guidance, it is possible to significantly increase accuracy and decrease complication rates. The pivotal principle of these mini-invasive techniques is to remove a small amount of volume of the nucleus of the intervertebral disc which results in a significant reduction in intradiscal pressure; allowing for a consequent reduction in compression of the nervous structures that generate spinal pain. However, it must be considered that this type of treatment is only addressed to contained disc herniations previously diagnosed with a suitable neuroimaging examination. There are different types of treatment using a variety of chemical, thermal or mechanical processes that result in partial removal of the nucleus pulposus. The purpose of this technical note is to illustrate mechanical disc decompression treatment via a percutaneous approach using the DISKOM device (DISKOM percutaneous discectomy probe, Biopsybell, Mirandola, Italy). Indications, complications and various methods of use are described in relation to the different levels of the spine to be treated.

Management of Postoperative Facet Cysts: A Report of 3 Cases

CASE

The exact underlying etiology behind synovial facet cysts remains unclear, and optimal surgical management continues to be a challenge. The authors present a series of 3 patients who underwent primary lumbar decompression and developed postoperative facet cysts within 6 months of index surgery requiring operative intervention. No patients had radiographic evidence of instability. Average follow-up after revision surgery was 14 months.

CONCLUSION

We report on the 3 cases with the phenomenon of postoperative facet cysts and present a complication that falls within the spectrum of lumbar decompression surgery with several successful treatment options.

A new approach to the treatment of spinal instability: Fusion or structural reinforcement without surgery?

Spinal instability related low back pain is a common condition resulting from degeneration and loss of stiffness of the intervertebral joint. In order to restore stability, highly invasive surgical fusion is needed for patients who are not responding to conservative treatment. Given the risk and complications of surgery, there has been the urge for improvement with a less invasive solution. Formation of vertebral body osteophytes is a common observation that has been treated as a degenerative condition. However, recent studies have associated it with reduced motion of spinal segments. Unlike the traditional view, we regard it as adaptive reactions aiming to repair and hypothesize that the spinal segments could be stabilized or fused by intentionally induced osteophytes growth at the mobile parts of the intervertebral joint. This could be achieved by injecting Bone Morphogenetic Proteins to the anterior ends of the vertebral bodies and/or the facet joints on both sides of two consecutive vertebrae percutaneously. If verified, it would be the first time that fusion could be achieved without surgery. Hence it would provide a valuable alternative to current treatments of spinal instability. Preliminary test in favor of this hypothesis is presented and we recommend that a formal study with sufficient number of samples is needed for verification.

Percutaneous CT-guided lumbar trans-facet pedicle screw fixation in lumbar microinstability syndrome: feasibility of a novel approach

STUDY DESIGN

Prospective experimental uncontrolled trial.

BACKGROUND

Lumbar microinstability (MI) is a common cause of lower back pain (LBP) and is related to intervertebral disc degeneration that leads to inability to adequately absorb applied loads. The term "microinstability" has recently been introduced to denote a specific syndrome of biomechanical dysfunction with minimal anatomical change. Trans-facet fixation (TFF) is a minimally invasive technique that involves the placement of screws across the facet joint and into the pedicle, to attain improved stability in the spine.

PURPOSE

In this study, we aimed to evaluate the effectiveness, in terms of pain and disability reduction, of a stand-alone TFF in treatment of patients with chronic low back pain (LBP) due to MI. Moreover, as a secondary endpoint, the purpose was to assess the feasibility and safety of a novel percutaneous CT-guided technique.

METHODS

We performed percutaneous CT-guided TFF in 84 consecutive patients presenting with chronic LBP attributable to MI at a single lumbar level without spondylolysis. Pre- and post-procedure pain and disability levels were measured using the visual analogue scale (VAS) and Oswestry Disability Index (ODI).

RESULTS

At 2 years, TFF resulted in significant reductions in both VAS and ODI scores. CT-guided procedures were tolerated well by all patients under light sedation with a mean procedural time of 45 min, and there were no reported immediate or delayed procedural complications.

CONCLUSION

TFF seems to be a powerful technique for lumbar spine stabilization in patients with chronic mechanical LBP related to lumbar MI. CT-guided technique is fast, precise, and safe and can be performed in simple analgo-sedation.

Safety and Efficacy of Anterior Lumbar Interbody Fusion for Discogenic Chronic Low Back Pain in a Short-stay Setting: Data From a Prospective Registry

Introduction As a possible treatment option for chronic lower back pain (CLBP) due to single-level degenerative disc disorder (DDD), the efficacy of anterior lumbar interbody fusion (ALIF) has been reviewed various times in the existing literature. Nevertheless, a scarcity of data exists pertaining to ALIF procedures carried out in a short-stay setting using an Enhanced Recovery after Surgery (ERAS) protocol, particularly concerning the safety. Methods Prospectively collected data are analyzed to study the efficacy and safety of short-stay ERAS ALIF in treatment of single-level DDD. Visual Analog Scale (VAS) in both back and leg pain along with the Oswestry Disability Index (ODI) were used to collect measure outcomes. The primary endpoint was a minimum clinically important difference (MCID) of ≥30% for the ODI at 12 months. Results Forty-four patients underwent surgery after failed long-term conservative treatment. MCID was achieved in 78%. Age was the only significant factor in association with MCID (p = 0.03), while gender, Modic changes, results of prognostic tests, prior surgery and smoking status had no significant influence on either MCID or change scores for any outcome measure. One complication in the form of transient new radiculopathy occurred in one patient (2.3%). Conclusion With overall positive outcomes in terms of both efficacy and safety, an ALIF procedure with subsequent implementation of an ERAS protocol in a short-stay setting can be an option for strictly selected patients with CLBP. Further study, however, possibly with a larger sample size, would be necessary to substantiate these findings.

Upright MRI after decompression of spinal stenosis and concurrent spondylolisthesis

OBJECTIVEThe treatment of patients with spinal stenosis and concurrent degenerative spondylolisthesis is controversial. Two large randomized controlled clinical trials reported contradictory results. The authors hypothesized that a substantial number of patients will show evidence of micro-instability after a sole decompression procedure.METHODSThis study was a retrospective analysis of all cases of lumbar spinal stenosis treated at the Frankfurt University Clinic (Universitätsklinik Frankfurt) from 2010 through 2013. Patients who had associated spondylolisthesis underwent upright MRI studies in flexion and extension for identification of subtle signs of micro-instability. Clinical outcome was assessed by means of SF-36 bodily pain (BP) and physical functioning (PF) scales.RESULTSA total of 21 patients were recruited to undergo upright MRI studies. The mean duration of follow-up was 65 months (SD 16 months). Of these 21 patients, 10 (47%) showed signs of micro-instability as defined by movement of > 4 mm on flexion/extension MRI. Comparison of mean SF-36 BP and PF scores in the group of patients who showed micro-instability versus those who did not showed no statistically significant difference on either scale.CONCLUSIONSThere seems to be a substantial subset of patients who develop morphological micro-instability after sole decompression procedures but do not experience any clinically significant effect of the instability.

Assessing the real benefits of surgery for degenerative lumbar spinal stenosis without instability and spondylolisthesis: a single surgeon experience with a mean 8-year follow-up

BACKGROUND

The degenerative lumbar spinal stenosis is one of the most commonly treated spinal disorders in older adults; despite its increasing frequency, it is not yet clear what the most effective therapy might be. The aim of this study is to investigate the very long term results of a homogenized cohort of patients suffering from lumbar spinal stenosis: the first subset of patients operated on with laminectomy and the second subset of patients was also advised to undergo laminectomy but never operated on.

METHODS

Patients from both subgroups were advised to undergo surgery, according to the same criteria, in the period between 2000 and 2010 and were re-evaluated in the period between January and December 2016.

RESULTS

Comparing the two subsets of patients, both suffering from clinically relevant LSS, the first subset returns a statistically significant clinical improvement at follow-up. The rate of excellent results decreases over years. Iatrogenic spinal instability incidence was found to be 3.8% in the present cohort.

CONCLUSIONS

Although the improvement of the first postoperative years decreases over time and despite the lack of general consensus, the lack of established shared guidelines and the limitations of this research, the results support the utilisation of surgery for the management of this condition.

LEVEL OF EVIDENCE

3.

Identifying subsets of patients with single-level degenerative disc disease for lumbar fusion: the value of prognostic tests in surgical decision making

BACKGROUND CONTEXT

Fusion surgery for degenerative disc disease (DDD) has become a standard of care, albeit not without controversy. Outcomes are inconsistent and a superiority over conservative treatment is debatable. Proper patient selection is key to clinical success, and a comprehensive understanding of prognostic tests does not currently exist.

PURPOSE

This study aimed to investigate the value of prognostic tests and sociodemographic factors in predicting outcomes following lumbar fusion surgery for DDD.

STUDY DESIGN

This is a retrospective analysis of prospectively collected data.

PATIENT SAMPLE

We included patients who underwent fusion surgery for DDD between 2010 and 2016.

OUTCOME MEASURES

The outcome measures included pre- and postoperative visual analog scale and Oswestry Disability Index scores.

MATERIALS AND METHODS

Prospectively collected patient data were reviewed for preoperative tests, perioperative data, and clinical outcomes. Prognostic tests used were discography, pantaloon cast test (PCT), Modic changes, and a summary of physical symptoms, coined "loading factor." By means of multivariate stepwise regression, prognostic factors that were useful in predicting outcomes were identified.

RESULTS

A total of 91 patients fit the inclusion criteria, with a mean follow-up of 33±16 months. Discography, Modic changes, and loading factor were of no value for predicting outcome scores (p>.05). A positive PCT predicted improved outcomes in back pain severity, but only in patients without prior surgery (p=.02). Demographic factors that showed a consistent reduction in back pain were female sex (p=.021) and no prior surgery at index level (p=.009). No other sociodemographic factors were of predictive value (p>.05).

CONCLUSIONS

In patients without prior surgery, the PCT appears to be the most promising prognostic tool. Other prognostic selection tools such as discography and Modic changes yield disappointing results. In this study, female patients and those without prior spine surgery appear to be most likely to benefit from fusion surgery for DDD.

Magnetic Resonance Imaging in degenerative disease of the lumbar spine: Fat Saturation technique and contrast medium

Purpose: To examine both anterior and posterior elements of the lumbar spine in patients with low back pain using MRI T2-weighted sequences with Fat Saturation (FS) and contrast enhanced T1-weighted sequences with FS.Materials and methods: Two thousand eight hundred and twenty (2820) patients (1628 male, 1192 female, mean age 54) presenting low back pain underwent MRI standard examination (Sagittal T1w TSE and T2w TSE, axial T1 SE) with the addition of sagittal and axial T2w Fat Sat (FS) sequences. Among all the patients, 987 (35%) have been studied adding Contrast Enhanced (CE) T1w FS sequences after administration of contrast medium. Results: Among 987 patients studied with contrast medium, we found: active-inflammatory intervertebral osteochondrosis in 646 (65%) patients; degenerative-inflammatory changes in facet joints (facet joint effusion, synovitis, synovial cysts) in 462 (47%); spondylolysis in 69 (7%); degenerative-inflammatory changes of the flava, interspinous and supraspinous ligaments in 245 (25%); inflammatory changes of posterior perispinal muscles in 84 (8%) patients. Conclusions: In patients with suspected no-disc-related low back pain, the implementation of T2w FS and CE T1w FS sequences to the standard MR protocol could allow a better identification of degenerative-inflammatory changes more likely associated to the pain. (www.actabiomedica.it)

Clinical and instrumental assessment of herniated discs after nucleoplasty: a preliminary study

BACKGROUND AND AIM

The therapy for low back pain boasts different approaches; one of these is nucleoplasty. We wanted to assess the effectiveness of nucleoplasty both by clinical response both by MR imaging evaluation, including even extrusions larger than one third of the spinal canal.

METHODS

Fifty-seven patients were treated with nucleoplasty in our hospital, 11 of these patients accepted both clinical and MRI evaluation after six months from treatment. The clinical evaluation was performed with Visual Analogue Scale (VAS) of pain, scored before and after the procedure. MRI evaluation consisted of analysing some imaging parameters of disc protrusions before and after the treatment.

RESULTS

In 10 out of 11 (91%) patients, VAS was reduced and only 1 out of 11 (9%) had the same pain after procedure. The mean of decrease of VAS score was 64%. In our population 8/11 (72%) patients had a herniation larger than 1/3 of the sagittal diameter of spinal canal and 100% of them had an improvement with a mean VAS reduction value of 75%. With MRI evaluation, the mean percentage of expulsion before and after treatment was respectively 40% and 34%. The expulsion decreased in 7/13 discs, remained equal in 4/13, and increased in 2/13 discs. Among the 9 larger protrusions, 3 didn't change, 6 reduced with a decrease mean value of 13%. Other MRI parameters didn't change significantly.

CONCLUSIONS

Our preliminary experience supports the success of coblation on pain relief, aiming to show progressively that this treatment is suitable even in case of great extrusions, which are generally treated only with surgical approach. It's not clear the usefulness of MRI control yet, even if in most of cases we could have found a certain reduction of expulsion degree.