Caudal Lumbar Disc Herniations Are More Likely to Require Surgery for Symptom Resolution

Which North American spine society disc herniation morphology descriptors are most associated with improvements in clinical outcomes after microdiscectomy?

Background

The North American Spine Society (NASS) assembled the first ever comprehensive naming system for describing lumbar disc disease, including lumbar disc herniation. The objectives of this study were (1) to determine which NASS descriptors are most predictive of independent patient-reported outcomes after microdiscectomy and (2) to identify the inter-rater reliability of each NASS descriptor.

Methods

Adult patients (≥18 years) who underwent a lumbar microdiscectomy from 2014-2021 were retrospectively identified. Patient-reported outcome measures (PROMs) were collected at preoperative, 3-month, and 1-year postoperative time points. Lumbar disc herniations were evaluated and classified on preoperative MRI using the NASS lumbar disc nomenclature specific to disc herniation.

Results

About 213 microdiscectomy patients were included in the final analysis. Herniation descriptors exhibiting the greatest reliability included sequestration status (κ=0.83), axial disc herniation area (κ=0.83), and laterality (κ=0.83). The descriptor with the lowest inter-rater reliability was direction of migration (κ=0.53). At 3 months, a sequestered herniation was associated with lower odds of achieving the minimal clinically important difference (MCID) for ODI (p=.004) and MCS (p=.032). At 12 months, a similar trend was observed for Oswestry Disability Index (ODI) MCID achievement (p=.001). At 3 months, a herniation with larger axial area was a predictor of MCID achievement in ODI (p=.004) and the mental component summary (MCS) (p=.009). Neither association persisted at 12 months; however, larger axial disc herniation area was able to predict MCID achievement in the Visual Analogue Scale (VAS) leg (p=.031) at 12 months.

Conclusions

The utility of the NASS nomenclature system in predicting postoperative outcomes after microdiscectomy has yet to be studied. We showed that sequestration status and disc area are both reliable and able to predict the odds of achieving MCID in certain clinical outcomes at 3 months and 12 months after surgery. Hence, preoperative imaging analysis of lumbar disc herniations may be useful in accurately setting patient expectations.

Microdiscectomy Insurance Medical Necessity Criteria Are Inconsistent and Unnecessarily Restrictive

BACKGROUND

Microdiscectomy for patients with chronic lumbar radiculopathy refractory to conservative therapy has significantly better outcomes than continued nonoperative management. The North American Spine Society (NASS) outlined specific criteria to establish medical necessity for elective lumbar microdiscectomy. We hypothesized that insurance providers have substantial variability among one another and from the NASS guidelines.

METHODS

A cross-sectional analysis of US national and local insurance companies was conducted to assess policies on coverage recommendations for lumbar microdiscectomy. Insurers were selected based on their enrollment data and market share of direct written premiums. The top 4 national insurance providers and the top 3 state-specific providers in New Jersey, New York, and Pennsylvania were selected. Insurance coverage guidelines were accessed through a web-based search, provider account, or telephone call to the specific provider. If no policy was provided, it was documented as such. Preapproval criteria were entered as categorical variables and consolidated into 4 main categories: symptom criteria, examination criteria, imaging criteria, and conservative treatment.

RESULTS

The 13 selected insurers composed roughly 31% of the market share in the United States and approximately 82%, 62%, and 76% of the market share for New Jersey, New York, and Pennsylvania, respectively. Insurance descriptions of symptom criteria, imaging criteria, and the definition of conservative treatment had substantial differences as compared with those defined by NASS.

CONCLUSION

Although a guideline to establish medical necessity was developed by NASS, many insurance companies have created their own guidelines, which have resulted in inconsistent management based on geographic location and selected provider.

CLINICAL RELEVANCE

Providers must be cognizant of the differing preapproval criteria needed for each in-network insurance company in order to provide effective and efficient care for patients with lumbar radiculopathy.

LEVEL OF EVIDENCE: 5

Propensity matched outcome analysis following microdiscectomy versus interlaminar endoscopic discectomy for L5-S1 disc herniation

Purpose

The main purpose of the study is to perform a propensity-matched functional outcome analysis following microdiscectomy (MD) versus interlaminar endoscopic lumbar discectomy (IELD) for L5-S1 disc herniation. Although many studies have compared endoscopic lumbar discectomy and microdiscectomy, few have compared the outcomes of microdiscectomy (MD) and interlaminar endoscopic discectomy (IELD) at the L5-S1 level.

Methods

This is a propensity-matched analysis of 100 patients (50 MD patients, 50 IELD patients) based on baseline covariates with a minimum of one-year follow-up. Patient-reported outcome measures were obtained from EMR during follow-up visits. Back pain and sciatic pain were assessed by the Visual Analogue Scale (VAS-B and VAS-L). Functional outcome was assessed using Oswestry Disability Index (ODI) Score and 12-item Short Form Survey (SF-12) score. Data were obtained at baseline (pre-op) and at 0, 1, 3, and 12 months post-operatively.

Results

Mean operative time was significantly lower (p < 0.001) in the IELD group (44 min) compared to the MD group (59 min). Mean VAS-B at the immediate and 1-month postoperative period was significantly (p < 0.001) lower in the IELD group (0.36, 0.24) when compared with the MD group (1.74, 1.16). There was no significant difference between IELD and MD groups with regard to improvement in sciatic pain (VAS-L). ODI scores at 1 month and 3 months post-operative period were significantly (p < 0.001) lower in the IELD group (30.1, 23.2) when compared with the MD group (41, 27.5). However, there was no significant difference between the two groups with regards to VAS-B, ODI, and SF-12 at 1-year follow-up.

Conclusion

Our findings indicate that the IELD group achieved better immediate and early postoperative outcomes despite no significant difference at one-year follow-up.

Association between chiropractic spinal manipulation and lumbar discectomy in adults with lumbar disc herniation and radiculopathy: retrospective cohort study using United States' data

OBJECTIVES

Chiropractic spinal manipulative therapy (CSMT) and lumbar discectomy are both used for lumbar disc herniation (LDH) and lumbosacral radiculopathy (LSR); however, limited research has examined the relationship between these therapies. We hypothesised that adults receiving CSMT for newly diagnosed LDH or LSR would have reduced odds of lumbar discectomy over 1-year and 2-year follow-up compared with those receiving other care.

DESIGN

Retrospective cohort study.

SETTING

101 million patient US health records network (TriNetX), queried on 24 October 2022, yielding data from 2012 query.

PARTICIPANTS

Adults age 18-49 with newly diagnosed LDH/LSR (first date of diagnosis) were included. Exclusions were prior lumbar surgery, absolute indications for surgery, trauma, spondylolisthesis and scoliosis. Propensity score matching controlled for variables associated with the likelihood of discectomy (eg, demographics, medications).

INTERVENTIONS

Patients were divided into cohorts according to receipt of CSMT.

PRIMARY AND SECONDARY OUTCOME MEASURES

ORs for lumbar discectomy; calculated by dividing odds in the CSMT cohort by odds in the cohort receiving other care.

RESULTS

After matching, there were 5785 patients per cohort (mean age 36.9±8.2). The ORs (95% CI) for discectomy were significantly reduced in the CSMT cohort compared with the cohort receiving other care over 1-year (0.69 (0.52 to 0.90), p=0.006) and 2-year follow-up (0.77 (0.60 to 0.99), p=0.040). E-value sensitivity analysis estimated the strength in terms of risk ratio an unmeasured confounding variable would need to account for study results, yielding point estimates for each follow-up (1 year: 2.26; 2 years: 1.92), which no variables in the literature reached.

CONCLUSIONS

Our findings suggest receiving CSMT compared with other care for newly diagnosed LDH/LSR is associated with significantly reduced odds of discectomy over 2-year follow-up. Given socioeconomic variables were unavailable and an observational design precludes inferring causality, the efficacy of CSMT for LDH/LSR should be examined via randomised controlled trial to eliminate residual confounding.