Patient-Reported Outcomes Following Lumbar Decompression Surgery: A Review of 2699 Cases

STUDY DESIGN

Retrospective case series.

OBJECTIVE

Despite numerous advances in the technology and techniques available to spinal surgeons, lumbar decompression remains the mainstay of degenerative lumbar spine surgery. It has proven efficacy in trials, but only limited evidence of advantage over conservative management in large scale systematic reviews. We collated data from a large surgically managed cohort to evaluate the patient-reported outcomes.

METHODS

We performed a retrospective analysis of a prospectively populated database. Patient demographics, surgical details, and patient outcomes (Spine Tango core outcome measures index [COMI]-Low Back) were collected for 2699 lumbar decompression surgeries.

RESULTS

Lumbar decompression was shown to be successful at improving leg pain (mean improvement in visual analogue scale [VAS] at 3 months = 4) and to a lesser extent, back pain (mean improvement in VAS at 3 months = 2.61). Mean improvement in COMI score was 3.15 for all-comers. Minimal clinically important improvement (MCID) in COMI score (-2 points) was achieved in 73% of patients by 2-year follow-up. Primary surgery was more effective than redo surgery: odds ratio 0.547 (95% CI 0.408-0.733, P < .001). The benefits across all outcomes were maintained for the 2-year follow-up period. Patients can be classified according to their outcome as "early responders"; achieving MCID by 3 months (61% primary vs 41% redo), "late responders"; achieving MCID by 2 years (15% vs 20%) or nonresponders (24% vs 39%).

CONCLUSIONS

Lumbar decompression is effective in improving quality of life in appropriately selected patients. Patient-reported outcome measures collected routinely and collated within a registry are a powerful tool for assessing the efficacy of lumbar spine interventions and allow accurate counseling of patients perioperatively.

Validation of a surgical invasiveness index in patients with lumbar spinal disorders registered in the Spine Tango registry

INTRODUCTION

Being able to quantify the invasiveness of a surgical procedure is important to weigh up its associated risks, since invasiveness governs the blood loss, operative time and likelihood of complications. Mirza et al. (Spine (Phila Pa 1976) 33:2651-2661, 2008) published an invasiveness index for spinal surgery. We evaluated the validity of a modified version of the Mirza invasiveness index (mMII), adapted for use with registry data.

METHODS

A cross-sectional analysis was performed with data acquired from the Spine Tango registry including 21,634 patients. The mMII was calculated as the sum of six possible interventions on each vertebral level: decompression, fusion and stabilization either on anterior or posterior structures. The association between the mMII and blood loss, operative time and complications was evaluated using multiple regression, adjusting for possible confounders.

RESULTS

The mean (± SD) mMII was 3.9 ± 5.0 (range 0-40). A 1-point increase in the mMII was associated with an additional blood loss of 12.8% (95% CI 12.6-13.0; p < 0.001) and an increase of operative time of 10.4 min (95% CI 10.20-10.53; p < 0.001). The R² for the blood loss model was of 43% and for operative time, 47%. The mean mMII was significantly (p < 0.001) higher in patients with surgical complications (4.5 ± 5.6) and general medical complications (6.5 ± 7.0) compared to those without (3.8 ± 4.9). Our results were comparable to those reported in the original publication of Mirza et al. CONCLUSION: The mMII appeared to be a valid measure of surgical invasiveness in our study population. It can be used in predictor models and to adjust for surgical case-mix when comparing outcomes in different studies or different hospitals/surgeons in a registry.

Risk Factors for Negative Global Treatment Outcomes in Lumbar Spinal Stenosis Surgery: A Mixed Effects Model Analysis of Data from an International Spine Registry

OBJECTIVE

To determine risk factors for negative global treatment outcomes as self-assessed by patients undergoing surgical treatment for lumbar spinal stenosis (LSS).

METHODS

Patients from the Spine Tango registry undergoing first-time surgery for LSS were analyzed. The primary outcome was global treatment outcomes measured at the last available follow-up ≥3 months postoperatively using a single question rating how much the operation had helped the patient's back problem (negative = no change/operation made things worse). A 2-level logistic mixed effects model with the treating department as the random effect was used to assess factors associated with a negative outcome.

RESULTS

A total of 4504 patients from 39 departments in 10 countries were included. Overall, 14.4% of patients reported a negative global treatment outcome after an average follow-up of 1.3 years. In patients with dominant leg pain, negative outcome was associated with higher baseline back pain; in those with dominant back pain, it was associated with higher baseline back pain, ASA (American Society of Anesthesiologists) ≥3, lower age, not having rigid stabilization, not having disc herniation, and the vertebral level of the most severely affected segment (L5/S1 vs. L3/4). Four departments had significantly higher odds of a negative outcome, whereas 1 department had significantly lower odds. Three out of the 4 negative effects were related to 2 departments from 1 country.

CONCLUSIONS

LSS surgery fails to help at least 1 in 10 patients. High baseline back pain is the most important factor associated with a negative treatment outcome. Department-level and potentially country-level factors of unknown origin explained a nonnegligible variation in the treatment results.

Non-operative treatment of lumbar spinal stenosis

BACKGROUND AND OBJECTIVE

Non-operative treatment is widely accepted for early stages of lumbar spinal stenosis. In general, a trial of conservative treatment is recommended prior to surgery. However, there is an ongoing debate regarding benefits from non-operative treatment and their duration.

METHODS

Thirty-eight patients were included in this prospective study. All patients received repeated epidural injections and facet joint injections as well as physiotherapy during a one week hospitalization. Patient characteristics, VAS scores, COMI and ODI scores and SF-36 were assessed prior to and immediately after treatment as well as after six, twelve, and 26 weeks. For six weeks after treatment, patients were asked to record a pain diary.

RESULTS

Back and leg pain scores improved significantly on VAS up to three months follow-up. COMI score improved significantly over the entire follow-up. Regarding quality of life, mental sub-scores showed no improvement. Physical component summary scores improved for the first three months.

CONCLUSIONS

Non-operative treatment offers pain relief and improves physical function for three months. COMI scores improve up to six months follow-up. Spine Tango registry offers standardized instruments for outcome evaluation of non-operative treatment.

Dynamic posterior stabilization for degenerative lumbar spine disease: a large consecutive case series with long-term follow-up by additional postal survey

INTRODUCTION

Dynamic stabilization of the degenerated spine was invented to overcome the negative side effects of fusion surgery like adjacent segment degeneration. Amongst various different implants DSS(®) is a pedicle-based dynamic device for stabilizing the spine and preserving motion. Nearly no clinical data of the implant have been reported so far. The current analysis presents results from a single spine surgeon who has been using DSS(®) for the past 5 years and recorded all treatment and outcome data in the international Spine Tango registry.

MATERIALS/METHODS

From the prospectively documented overall patient pool 436 cases treated with DSS(®) could be identified. The analysis was enhanced with a mailing of COMI patient questionnaires for generating longer-term follow-ups up to 4 years.

RESULTS

387 patients (189 male, 198 female; mean age 67.3 years) with degenerative lumbar spinal disease including degenerative spondylolisthesis (6.1 %) could be evaluated. The type of degeneration was mainly spinal stenosis (89.9 %). After a mean follow-up of 1.94 years, the COMI score and NRS back and leg pain improved significantly and to a clinically relevant extent. The postoperative trend analysis could not determine a relevant deterioration of these outcomes until 4 years postoperative. 10 patients were revised (2.6 %) and the implant was removed; in most cases, a fusion was performed. Another 5 cases (1.3 %) had an extension of the dynamic stabilization system to the adjacent level. 84.2 % of patients rated that the surgery had helped a lot or had helped.

DISCUSSION

The results of this large consecutive series with a follow-up up to 4 years could demonstrate a good and stable clinical outcome after posterior dynamic stabilization with DSS(®). For degenerative diseases of the lumbar spine, this treatment seems to be a valid alternative to fusion surgery.

Total disc arthroplasty versus anterior cervical interbody fusion: use of the Spine Tango registry to supplement the evidence from randomized control trials

BACKGROUND CONTEXT

Several randomized controlled trials (RCTs) have compared patient outcomes of anterior (cervical) interbody fusion (AIF) with those of total disc arthroplasty (TDA). Because RCTs have known limitations with regard to their external validity, the comparative effectiveness of the two therapies in daily practice remains unknown.

PURPOSE

This study aimed to compare patient-reported outcomes after TDA versus AIF based on data from an international spine registry.

STUDY DESIGN AND SETTING

A retrospective analysis of registry data was carried out.

PATIENT SAMPLE

Inclusion criteria were degenerative disc or disc herniation of the cervical spine treated by single-level TDA or AIF, no previous surgery, and a Core Outcome Measures Index (COMI) completed at baseline and at least 3 months' follow-up. Overall, 987 patients were identified.

OUTCOME MEASURES

Neck and arm pain relief and COMI score improvement were the outcome measures.

METHODS

Three separate analyses were performed to compare TDA and AIF surgical outcomes: (1) mimicking an RCT setting, with admission criteria typical of those in published RCTs, a 1:1 matched analysis was carried out in 739 patients; (2) an analysis was performed on 248 patients outside the classic RCT spectrum, that is, with one or more typical RCT exclusion criteria; (3) a subgroup analysis of all patients with additional follow-up longer than 2 years (n=149).

RESULTS

Matching resulted in 190 pairs with an average follow-up of 17 months that had no residual significant differences for any patient characteristics. Small but statistically significant differences in outcome were observed in favor of TDA, which are potentially clinically relevant. Subgroup analyses of atypical patients and of patients with longer-term follow-up showed no significant differences in outcome between the treatments.

CONCLUSIONS

The results of this observational study were in accordance with those of the published RCTs, suggesting substantial pain reduction both after AIF and TDA, with slightly greater benefit after arthroplasty. The analysis of atypical patients suggested that, in patients outside the spectrum of clinical trials, both surgical interventions appeared to work to a similar extent to that shown for the cohort in the matched study. Also, in the longer-term perspective, both therapies resulted in similar benefits to the patients.

Predictors of improvement in quality of life and pain relief in lumbar spinal stenosis relative to patient age: a study based on the Spine Tango registry

BACKGROUND

An open decompression is the most common treatment for lumbar spinal canal stenosis (LSS), even in the elderly. However, it is not clear whether the treatment outcome is age dependent. The main purpose of this study was to evaluate the improvement in quality of life (QoL) and pain relief, after open decompression for LSS in relation to patient age.

METHODS

The study was performed on the basis of Spine Tango registry data. The database query resulted in 4768 patients from 40 international Spine Tango centres. The patients were subdivided into three age groups: (1) 20-64, (2) 65-74, and (3) ≥75 years. In multivariate logistic regression models, predictors for improvement in QoL and achievement of the minimum clinically relevant change in pain of two points were analysed.

RESULTS

All groups benefited from significant improvement in QoL and back and leg pain relief. Age group had no significant influence on the outcomes. The preoperative status of each outcome was a predictor for its own postoperative outcome. Fewer previous surgeries, rigid or dynamic stabilization, and lower patient comorbidity also had a partially predictive influence for one or the other outcome.

CONCLUSIONS

Our results confirm that all age groups significantly benefit from the open decompressive treatment of LSS. Age group had no significant influence on any outcome.

Viscoelastic Disc Arthroplasty Provides Superior Back and Leg Pain Relief in Patients with Lumbar Disc Degeneration Compared to Anterior Lumbar Interbody Fusion

BACKGROUND

Lumbar disc degeneration (LDD) is one of the most frequently diagnosed spinal diseases. The symptoms these disorders cause are anticipated to increase as the population in Western countries ages.

PURPOSE

Compare back and leg pain alleviation in patients with LDD and a viscoelastic disc prosthesis documented in the SWISSspine registry versus patients with anterior lumbar interbody fusion documented in the Spine Tango registry.

STUDY DESIGN

Prospectively collected clinical and outcome data in two independent spine registries. Outcome Measures were back and leg pain relief on 0 to 10 numerical rating scales.

MATERIALS AND METHODS

The analysis included a single surgeon series of 48 patients with viscoelastic total disc replacement (VTDR) from the SWISSspine registry which were compared to 131 patients with anterior lumbar interbody fusion (ALIF) from the Spine Tango registry. Two linear multivariate regression models were built to assess the associations of patient characteristics with back and leg pain relief. The following covariates were included in the models: patient age and sex, disc herniation as additional diagnosis, number of treated segments, level of treated segment, treatment type (VTDR, ALIF), preoperative back and leg pain levels and follow-up interval.

RESULTS

Both models showed VTDR to be associated with significantly higher back (2.76 points; 95% confidence interval (CI) 1.78 - 3.73; p < 0.001) and leg pain (2.12 points; 95% CI 1.12 to 3.13; p < 0.001) relief than ALIF. Other influential factors for higher back pain relief were female sex compared with male sex (1.03 additional points; 95% CI 0.27 to 1.78; p = 0.008), monosegmental surgery compared with bisegmental surgery (1.02 additional points; 95% CI 0.21 to 1.83; p = 0.014), and higher back pain at baseline (0.87 points additional pain relief per level of preoperative back pain; 95% CI 0.70 to 1.03; p < 0.001). Other influential factors for leg pain relief were monosegmental surgery (0.93 additional points; 95% CI 0.10 to 1.77; p = 0.029) and higher leg pain at baseline (0.83 points additional pain relief per level of preoperative leg pain; 95% CI 0.70 to 0.96). In both models the L3/4 segment showed 2.36 points (95% CI -4.27 to -0.45; p = 0.016) and 3.69 points (95% CI -5.66 to -1.71; p < 0.001) less pain relief than L5/S1.

DISCUSSION

Significantly higher back and leg pain relief were observed after viscoelastic total disc replacement in comparison with anterior lumbar interbody fusion. The new less rigid materials used in the second generation total disc replacements (TDRs) may make artificial disc replacement an increasingly attractive option for patients with degenerative lumbar disc disease. Further controlled and long-term follow-up studies are required for more detailed comparisons of the outcomes of these types of disc implants. The Freedom Lumbar Disc is limited by U.S. federal law to investigational use only.