Minimum Clinically Important Difference: Current Trends in the Spine Literature

Unilateral biportal endoscopic versus microscopic transforaminal lumbar interbody fusion for degenerative lumbar spinal stenosis in China: study protocol for a prospective, randomised, controlled, non-inferiority trial

INTRODUCTION

Degenerative lumbar spinal stenosis is a common cause of low back or leg pain and disability in the elderly population. Patients with spinal stenosis who fail to respond to conservative treatment often require surgical interventions. Minimally invasive transforaminal lumbar interbody fusion (TLIF) with microscopic tubular technique (MT-TLIF) is a well-established procedure for lumbar spinal stenosis. Recently, a novel MIS technique, unilateral biportal endoscopic TLIF (UBE-TLIF), has been frequently performed to treat spinal stenosis. However, the efficacy and safety of using UBE-TLIF in this population have not been well examined.

METHODS AND ANALYSIS

A total of 96 patients with lumbar spinal stenosis will be randomly assigned to the UBE-TLIF group or the MT-TLIF group at a 1:1 ratio to receive UBE-TLIF or MT-TLIF treatment respectively. The primary outcome is the Oswestry Disability Index (ODI) score at 1 year after receiving the surgery. Secondary outcomes include the ODI scores at additional time points, Visual Analogue Scale score, 36-Item Short Form Survey questionnaire, EuroQol 5 Dimensions questionnaire, radiological measurements (disc height, lumbar lordosis angles and vertebral fusion rate) and general condition during hospitalisation.

ETHICS AND DISSEMINATION

This protocol is approved by the Medical Ethics Committee of the Third Affiliated Hospital of Sun Yat-sen University. All participants of the study will be well informed and written informed consent will be requested. Findings from this trial will be published in peer-reviewed publications, specifically in orthopedic and spinal journals. The completion of this study will not only examine the use of UBE-TLIF in lumbar spinal stenosis but also provide helpful clinical references.

TRIAL REGISTRATION NUMBER

ChiCTR2300069333.

Clinical relevance of patient-reported outcome measures in patients who have undergone total hip arthroplasty: a systematic review

INTRODUCTION

In orthopaedic research, it is crucial to determine changes that are statistically significant and clinically meaningful. One approach to accomplish this is by calculating the Minimal Clinically Important Difference (MCID), the Clinically Important Differences (CID), the Minimum Detectable Change (MDC), the Minimal Important Change (MIC), and the Patient Acceptable Symptom State (PASS) values. These tools assist medical professionals in comprehending the patient's viewpoint, enabling them to establish treatment objectives that align with patients' desires and expectations. The present systematic review investigated the MCID, MIC, CID, MDC, and PASS of the most used PROMs to assess patients who have undergone THA.

METHODS

This systematic review followed the 2020 PRISMA guidelines. Web of Science, Embase, and PubMed were accessed in March 2024 without time constraints or additional filters. All the clinical investigations which evaluated data tools (MCID, MIC, CID, MDC, and PASS) to assess the clinical relevance of PROMs in THA were accessed. Articles in Spanish, Italian, German, and English were eligible. Studies with levels of evidence I to III were eligible.

RESULTS

Data from 100,824 patients were collected. All relevant demographic data were analysed and summarised. In addition, the MCID, MIC, CID, MDC and PASS of the COMI, HOOS, SF-36, OHS, Oxford-12, PROMIS-PF, SF-12, and WOMAC scores for THA were determined.

CONCLUSION

Current evidence recommends to collect MCIDs based on anchors routinely. These values should be used as complementary tools to determine the clinical effectiveness of a treatment instead of solely relying on statistically significant improvements.

LEVEL OF EVIDENCE

Level IV, systematic review and meta-analysis.

Studies in the Falls Efficacy Scale-International for patients with cervical compressive myelopathy: Reliability, validity, and minimum clinically important difference

CONTEXT

Patients with cervical compressive myelopathy (CCM) often complain of body balance problems, such as fear of falling and bodily unsteadiness. However, no accepted patient-reported outcome measures (PROMs) for this symptomatology exist. The Falls Efficacy Scale-International (FES-I) is one of the most widely used PROMs for evaluating impaired body balance in various clinical fields.

OBJECTIVE

To examine reliability, validity, and minimum clinically important difference (MCID) of the FES-I for the evaluation of impaired body balance in patients with CCM.

METHODS

Patients who underwent surgery for CCM were retrospectively reviewed. The FES-I was administered preoperatively and at 1 year postoperatively. Further, cJOA-LE score (subscore for lower extremities in the Japanese Orthopaedic Association score for cervical myelopathy) and stabilometric data, obtained at the same time points of the FES-I administration, were analyzed. Reliability was examined through internal consistency with Cronbach's alpha. Convergent validity was studied using correlation analysis. The MCID was estimated using anchor- and distribution-based methods.

RESULTS

Overall, 151 patients were included for analysis. Cronbach's alpha coefficient was the acceptable value of 0.97 at both baseline and 1 year postoperatively. As for convergent validity, the FES-I had significant correlations with the cJOA-LE score and stabilometric parameters both at baseline and 1 year postoperatively. The MCID calculated using anchor- and distribution-based methods was 5.5 and 10, respectively.

CONCLUSION

FES-I is a reliable and valid PROM to evaluate body balance problems for the CCM population. The established thresholds of MCID can help clinicians recognize the clinical significance of changes in patient status.

The Influence of Multilevel Spinal Deformity Surgery on the EuroQol 5 Dimensions' (EQ-5D) Questionnaire and Residential Status in the Elderly: A Prospective, Observational, Multicenter Study

STUDY DESIGN

Multicenter, international prospective study.

OBJECTIVE

This study investigated the clinical outcome up to 2 years after multi-level spinal deformity surgery in the elderly by reporting the minimal clinically important difference (MCID) of EuroQol 5-dimensions (EQ-5D), EQ-VAS, and residential status.

METHODS

As an ancillary study of 219 patients ≥60 years with spinal deformity undergoing primary instrumented fusion surgery of ≥5 levels, this study focuses on EQ-5D (3-L) as the primary outcome and EQ-VAS and residential status as secondary outcomes. Data on EQ-5D were compared between pre-operatively and postoperatively at 10 weeks, 12 months, and 24 months. An anchor-based approach was used to calculate the MCID.

RESULTS

The EQ-5D index and EQ-VAS, respectively, improved significantly at each time point compared to pre-operatively (from .53 (SD .21) and 55.6 (SD 23.0) pre-operatively to .64 (SD .18) and 65.8 (SD 18.7) at 10 weeks, .74 (SD .18) and 72.7 (SD 18.1) at 12 months, and .73 (SD .20) and 70.4 (SD 20.4) at 24 months). 217 (99.1%) patients lived at home pre-operatively, while 186 (88.6%), 184 (98.4%), and 172 (100%) did so at 10 weeks, 12 months, and 24 months, respectively. Our calculated MCID for the EQ-5D index at 1 year was .22 (95% CI .15-.29).

CONCLUSIONS

The EQ-5D index significantly increased at each time point over 24 months after ≥5 level spinal deformity surgery in elderly patients. The MCID of the EQ-5D-3 L was .22. Patients living at home pre-operatively can expect to be able to live at home 2 years postoperatively.

Effectiveness and Safety of Pharmacopuncture on Inpatients with Tension Headache Caused by Traffic Accidents: A Pragmatic Randomized Controlled Trial

Background: This study investigated the effectiveness and safety of pharmacopuncture for pain relief and functional improvement in patients with traffic accident (TA)-induced acute tension headaches. Methods: The study employed a parallel, single-centered, pragmatic, randomized controlled trial design. Eighty patients complaining of acute tension headaches were randomized into the integrative Korean medicine treatment (IKM treatment) group and the pharmacopuncture group on suboccipital muscles (suboccipital muscles pharmacopuncture + IKM treatment), with 40 participants assigned to each group. The patients in the pharmacopuncture group underwent pharmacopuncture as an add-on therapy, consisting of three sessions. Both groups were reassessed 2 months post-intervention. To assess the outcomes, the Numeric Rating Scale (NRS) for Headache, NRS for Neck Pain, Headache Disability Index, Headache Impact Test-6, EuroQol 5-Dimension, and Patient Global Impression of Change were used. Results: The improvement in the outcomes of the pharmacopuncture group was significantly greater than that of the comparison group on day 4 of hospitalization in terms of pain (difference in NRS of headache -2.59, 95% CI -3.06 to -2.12; NRS of Neck pain -1.05, 95% CI -1.50 to -0.59) and function (difference in HDI -24.78, 95% CI, -31.79 to -17.76; HIT-6 -6.13, 95% CI, -9.47 to -2.78). Additionally, in 2 months of follow-up, the recovery rate of headache was significantly higher in the pharmacopuncture group than in the comparison group. Conclusions: The pharmacopuncture group demonstrated superior outcomes in symptom improvement than the comparison group did, providing insights into novel and useful applications of pharmacopuncture in the clinical practice of Korean medicine.

Anterior Spinal Fusion for Thoraco-Lumbar Idiopathic Scoliosis Comparing Less Invasive Concave versus Traditional Convex Approach: A Pilot Study

Background/Objectives: Anterior spinal fusion for primary thoracolumbar or lumbar (TL/L) adolescent idiopathic scoliosis, AIS, has advantages over posterior fusion, particularly in saving motion segments below the fusion construct. Traditionally, the approach is anterolaterally from the convexity. In adult degenerative scoliosis, the lateral or anterolateral approach may be performed from the traditional or from the concave approach which is less invasive and gives comparable outcomes. The purpose of the present pilot study was to assess the feasibility of the less invasive concave approach for younger AIS patients and compare it to the traditional convex approach over a 5-year follow-up period. Methods: The two cohorts were assessed by comparing pre- to postoperative radiographs, and clinical outcomes for pain, function, self-perception of appearance, and opinion of surgical success were prospectively obtained. Results: Radiographs found that primary TL/L scoliosis significantly improved from 53° to 18° (65%) for both the concave and convex cohorts. Sagittal alignments remained stable and there was no difference between cohorts. Coronal balance improved in both cohorts and sagittal balance was stable for both. Clinically, VAS back pain improved significantly for both cohorts initially and remained improved in the concave group. Leg pain, pain drawing, ODI disability, and VAS appearance scores improved and there was no difference between cohorts. The self-rating of success of the procedure was 100% at early and late follow-up periods. There were no neurological/surgical complications. Conclusions: The concave approach for anterior fusion for TL/L AIS is feasible with comparable radiographic and clinical outcomes to the traditional approach.

Immediate vs Gradual Brace Weaning Protocols in Adolescent Idiopathic Scoliosis: A Randomized Clinical Trial

Importance

Lack of evidence and consensus for brace weaning protocol in adolescent idiopathic scoliosis (AIS) results in clinicians prescribing gradual weaning in the hope of avoiding curve deterioration after weaning. However, gradual weaning contributes to prolonged brace wear, which can affect spinal stiffness and health-related quality of life (HRQoL).

Objective

To determine whether gradual weaning results in better curve magnitude and truncal balance maintenance after brace weaning vs immediate brace removal for patients with AIS.

Design, Setting, and Participants

This was an open-labeled randomized clinical trial commenced in April 2017 with 24-month follow-up completed in January 2023. Outcome assessors were masked to weaning protocol assigned. The study took place at a territory-wide tertiary scoliosis clinic serving the largest number of referrals in the local population. Patients with AIS ready to wean off of brace wear were eligible (402 were screened; 33 were excluded [15 for <18 hours/day of brace-wear compliance before weaning, 11 were treated with Milwaukee brace, and 7 declined to participate]; and 369 were included), and those who were treated with a custom molded thoracolumbosacral orthosis and had reached skeletal maturity were consecutively recruited.

Interventions

Patients were randomized to gradual weaning protocol (n = 176) with an additional 6 months of nighttime wear before completely stopping or immediate weaning protocol (n = 193) with immediate brace removal at recruitment.

Main Outcomes and Measures

Changes in major curve Cobb angle and truncal balance from the time of weaning to 6-month, 12-month, and 24-month follow-up. HRQoL was also assessed using the refined Scoliosis Research Society 22-item and EuroQol 5-dimension questionnaires.

Results

A total of 369 patients (mean [SD] age, 14.9 [1.1] years; 304 [83.4%] girls) were randomized with 284 (77.0%) completing 24-month longitudinal follow-up. Immediate and gradual weaning groups had no significant differences in change of major Cobb angle at postweaning 6-month (difference, -0.6°; 95% CI, -1.4 to 0.2; P = .17), 12-month (difference, -0.3°; 95% CI, -1.2 to 0.6; P = .47), and 24-month (difference, -0.3°; 95% CI, -1.2 to 0.7; P = .60) follow-up. The number of curve progression, nonprogression, and rebound cases were comparable (χ22 = 2.123; P = .35). Postweaning changes in truncal balance and HRQoL demonstrated no significant differences between groups.

Conclusions

Gradual weaning did not demonstrate superiority to immediate weaning with predefined criteria of Cobb angle and truncal balance maintenance and HRQoL after brace weaning. Gradual and immediate weaning achieved very similar maintenance of brace outcomes in AIS. We therefore recommend the consideration of immediate brace weaning, which aims to benefit patients with earlier time for increased exercises and activity level.

Trial Registration

ClinicalTrials.gov Identifier: NCT03329716.

Depression State Correlates with Functional Recovery Following Elective Lumbar Spine Fusion

OBJECTIVE

To determine how depression state impacts postoperative Patient-Reported Outcomes Measurement Information System (PROMIS) scores and achievement of minimum clinically important difference (MCID) following lumbar fusion. Depression has been shown to negatively impact outcomes following numerous orthopedic surgeries. Situational and major clinical depression can differentially affect postoperative outcomes.

METHODS

Adult patients undergoing elective 1-3 level lumbar fusion were reviewed. Patients with a formal diagnosis of major depression were classified as "clinically depressed" whereas patients with at least "mild" PROMIS Depression scores in the absence of formal depression diagnosis were deemed "situationally depressed." analysis of variance testing was used to assess differences within and between groups. Multivariate regression was used to identify features associated with the achievement of MCID.

RESULTS

Two hundred patients were included. The average age was 65.9 ± 12.2 years. 75 patients (37.5%) were nondepressed, 66 patients (33.0%) were clinically depressed, and 59 patients (29.5%) were situationally depressed. Situationally depressed patients had worse preoperative physical function (PF) and pain interference (PI) scores and were more likely to have severe symptoms (P = 0.001, P = 0.001). All groups improved significantly from preoperative baseline scores. All groups met MCID PF at different rates, with highest proportion of situationally depressed reaching this metric (P = 0.03). Rates of achieving MCID PI were not significantly different between groups (P = 0.47). Situational depression was predictive of achieving MCID PF (P = 0.002) but not MCID PI.

CONCLUSIONS

Our study investigated the relationship between depression and postoperative PROMIS scores and identified situationally depressed patients as having the worst preoperative impairment. Despite this, the situationally depressed cohort had the highest likelihood of achieving MCID PF, suggestive of a bidirectional relationship between lumbar degenerative disease and subclinical, situational depression. These findings may help guide preoperative counseling on expectations, and patient selection.

Reassessing the minimum 2-year follow-up standard after lumbar decompression surgery: a 2-month follow-up seems to be an acceptable minimum

BACKGROUND CONTEXT

Academic orthopedic journals and specialty societies emphasize the importance of two-year follow-up for patient-reported outcome measures (PROMS) after spine surgery, but there are limited data evaluating the appropriate length of follow-up.

PURPOSE

To determine whether PROMs, as measured by the Oswestry Disability Index (ODI), would change significantly after 2-months postoperatively after lumbar decompression surgery for disc herniation or spinal stenosis.

STUDY DESIGN

Retrospective analysis of prospectively and consecutively enrolled patients undergoing lumbar decompression surgery between 2020 and 2021 from a single surgeon spine registry.

PATIENT SAMPLE

One hundred sixty-nine patients.

OUTCOME MEASURES

ODI, achievement of minimum clinically important difference (MCID), revisions.

METHODS

Patients without a preoperative baseline score were excluded. Completion of the ODI questionnaire was assessed at the follow-up points. The median ODI was compared at time baseline, 2-month, 1-year and 2-year follow-up. Risk of reoperation was assessed with receiver operating characteristic (ROC) analysis to identify at-risk ODI thresholds of requiring reoperation.

RESULTS

Median ODI significantly improved at all time points compared to baseline (median baseline ODI: 40; 2-month ODI: 16, p=.001; 1-year ODI: 11.1, p=.001; 2-year ODI: 8, p=.001). Posthoc analysis demonstrated no difference between 2-months, 1-year and 2-year postoperative ODI (p=.9, p=.468, p=.606). The MCID was met in 87.9% of patients at 2 months, 80.7% at 1 year, and 87.3% at 2 years postoperatively. Twelve patients (7.7%) underwent revision surgery between 2 months and 2 years after the index surgery (median time to revision: 5.6 months). ROC curve analysis demonstrated that an ODI score ≥24 points at 2-months yielded a sensitivity of 85.7% and a specificity of 71.8% for predicting revision after lumbar decompression (AUC=0.758; 95% CI: 0.613-0.903). The Youden optimal threshold value of ≥24 points at 2-month postop ODI yielded an odd ratio (OR) for revision of 15.3 (CI: 1.8-131.8; p=.004). The positive predictive value (PPV) and negative predictive value (NPV) were 15.4% and 98.8%, respectively.

CONCLUSION

Two-year clinical follow-up may not be necessary for future peer-reviewed lumbar decompression surgery studies given that ODI plateaus at 8 weeks. Patients with a score ≥24 points at 2-months postoperatively have a higher risk of requiring a second surgery within the first 2 years and warrant continued follow-up.

Calculation of the minimum clinically important difference (MCID) using different methodologies: case study and practical guide

INTRODUCTION

Establishing thresholds of change that are actually meaningful for the patient in an outcome measurement instrument is paramount. This concept is called the minimum clinically important difference (MCID). We summarize available MCID calculation methods relevant to spine surgery, and outline key considerations, followed by a step-by-step working example of how MCID can be calculated, using publicly available data, to enable the readers to follow the calculations themselves.

METHODS

Thirteen MCID calculations methods were summarized, including anchor-based methods, distribution-based methods, Reliable Change Index, 30% Reduction from Baseline, Social Comparison Approach and the Delphi method. All methods, except the latter two, were used to calculate MCID for improvement of Zurich Claudication Questionnaire (ZCQ) Symptom Severity of patients with lumbar spinal stenosis. Numeric Rating Scale for Leg Pain and Japanese Orthopaedic Association Back Pain Evaluation Questionnaire Walking Ability domain were used as anchors.

RESULTS

The MCID for improvement of ZCQ Symptom Severity ranged from 0.8 to 5.1. On average, distribution-based methods yielded lower MCID values, than anchor-based methods. The percentage of patients who achieved the calculated MCID threshold ranged from 9.5% to 61.9%.

CONCLUSIONS

MCID calculations are encouraged in spinal research to evaluate treatment success. Anchor-based methods, relying on scales assessing patient preferences, continue to be the "gold-standard" with receiver operating characteristic curve approach being optimal. In their absence, the minimum detectable change approach is acceptable. The provided explanation and step-by-step example of MCID calculations with statistical code and publicly available data can act as guidance in planning future MCID calculation studies.

Artificial Intelligence for Clinically Meaningful Outcome Prediction in Orthopedic Research: Current Applications and Limitations

PURPOSE OF REVIEW

Patient-reported outcome measures (PROM) play a critical role in evaluating the success of treatment interventions for musculoskeletal conditions. However, predicting which patients will benefit from treatment interventions is complex and influenced by a multitude of factors. Artificial intelligence (AI) may better anticipate the propensity to achieve clinically meaningful outcomes through leveraging complex predictive analytics that allow for personalized medicine. This article provides a contemporary review of current applications of AI developed to predict clinically significant outcome (CSO) achievement after musculoskeletal treatment interventions.

RECENT FINDINGS

The highest volume of literature exists in the subspecialties of total joint arthroplasty, spine, and sports medicine, with only three studies identified in the remaining orthopedic subspecialties combined. Performance is widely variable across models, with most studies only reporting discrimination as a performance metric. Given the complexity inherent in predictive modeling for this task, including data availability, data handling, model architecture, and outcome selection, studies vary widely in their methodology and results. Importantly, the majority of studies have not been externally validated or demonstrate important methodological limitations, precluding their implementation into clinical settings. A substantial body of literature has accumulated demonstrating variable internal validity, limited scope, and low potential for clinical deployment. The majority of studies attempt to predict the MCID-the lowest bar of clinical achievement. Though a small proportion of models demonstrate promise and highlight the utility of AI, important methodological limitations need to be addressed moving forward to leverage AI-based applications for clinical deployment.

Effectiveness of lumbar motion style acupuncture treatment on inpatients with acute low back pain: A pragmatic, randomized controlled trial

BACKGROUND AND PURPOSE

This parallel, single-center, pragmatic, randomized controlled study aimed to investigate the effectiveness and safety of motion style acupuncture treatment (MSAT; a combination of acupuncture and Doin therapy) to reduce pain and improve the functional disability of patients with acute low back pain (aLBP) due to road traffic accidents.

MATERIALS AND METHODS

Ninety-six patients with aLBP admitted to the Haeundae Jaseng Hospital of Korean Medicine in South Korea due to traffic accidents were treated with integrative Korean medicine (IKM) with additional 3-day MSAT sessions during hospitalization (MSAT group, 48 patients) or without (control group, 48 patients), and followed up for 90 days.

RESULTS

The mean numeric rating scale (NRS) scores of low back pain (LBP) of the MSAT and control groups were both 6.7 (95% confidence interval [CI]: 6.3, 7.1) at baseline. After completing the third round of all applicable treatment sessions (the primary endpoint in this study), the mean NRS scores of the MSAT and control groups were 3.76 (95% CI: 3.54, 3.99) and 5.32 (95% CI: 5.09, 5.55), respectively. The difference in the mean NRS score between the two groups was 1.56 (95% CI: 1.25, 1.87).

CONCLUSION

IKM treatment combined with MSAT can reduce pain and improve the range of motion of patients with aLBP.

TRIAL REGISTRATION

This trial is registered at ClinicalTrial.gov (NCT04956458).

Worse Preoperative Disability is Predictive of Improvement in Disability After Complex Adult Spinal Deformity Surgery

STUDY DESIGN

Retrospective Cohort Study.

OBJECTIVES

Few previous studies have examined the relationship between preoperative disability and patient outcomes after complex adult spinal deformity surgery. In this study, we hypothesized that patients with worse preoperative disability would be more likely achieve a clinically significant improvement in their symptoms after surgery.

METHODS

Demographics, comorbidities, surgical data, and health related survey results were analyzed from a consecutive series of adults (≥18 years old) who underwent spinal deformity correction, instrumentation, and fusion. Patients included had 6 or more levels fused and their surgery performed at single institution between 2015 and 2018 with minimum 2 year follow up.

RESULTS

A total of 108 patients met inclusion criteria. Bivariate analysis demonstrated the following as having a greater probability of reaching minimum clinically important difference (MCID) at 2 years postoperatively: >50th percentile Oswestry Disability Index (ODI) score (ODI >36), cardiac comorbidities, and use of pelvic fixation, pedicle subtraction osteotomy, and transforaminal lumbar interbody fusion. Conversely, baseline Scoliosis research society score (SRS) >50th percentile (SRS ≥62) and use of vertebral column resection (VCR) were significant predictors of not reaching MCID at 2 years. On logistic regression analysis, >50th percentile ODI score (ODI >36) was identified as the only independent predictor of achieving MCID.

CONCLUSIONS

Patients with greater disability, independent of other preoperative or surgical factors, are more likely to have clinically significant improvement in their daily functioning after complex deformity surgery. For patients who undergo surgical intervention for severe or progressive deformity, including VCR, MCID might be an ineffective outcome measure.

What's the clinical significance of VAS, AOFAS, and SF-36 in progressive collapsing foot deformity

BACKGROUND

This study aimed to ascertain the minimal clinically important difference (MCID), and substantial clinical benefit (SCB) of the American Orthopedic Foot and Ankle Society (AOFAS) scale, visual analog scale (VAS) for pain, and Short Form-36 Health Survey (SF-36) in progressive collapsing foot deformity (PCFD) surgery.

METHODS

In this retrospective cohort study, a total of 84 patients with PCFD (84 feet) who underwent surgery between July 2015 and April 2021 were included. The study assessed the patients' subjective perception, as well as their VAS, AOFAS, and SF-36 scores at a minimum two-year follow-up, and these data were subjected to statistical analysis. The study utilized Spearman correlation analysis to determine the degree of correlation between patients' subjective perception and their VAS, AOFAS, and SF-36 scores. The minimal detectable change (MDC), MCID, and SCB for VAS, AOFAS, and SF-36 were calculated using both distribution- and anchor-based methods. The classification outcomes obtained from the distribution- and anchor-based methods were assessed using Cohen's kappa.

RESULTS

Based on the subjective perception of the patients, a total of 84 individuals were categorized into three groups, with 7 in the no improvement group, 14 in the minimum improvement group, and 63 in the substantial improvement group. Spearman's correlation analysis indicated that the patients' subjective perception exhibited a moderate to strong association with VAS, AOFAS, SF-36 PCS, and SF-36 MCS, with all coefficients exceeding 0.4. The MCID of VAS, AOFAS, SF-36 PCS, and SF-36 MCS in PCFD surgery were determined to be 0.93, 5.84, 4.15, and 4.10 points using the distribution-based method and 1.50, 10.50, 8.34, and 3.03 points using the anchor-based method. The SCB of VAS, AOFAS, SF-36 PCS, and SF-36 MCS in PCFD surgery were 2.50, 18.50, 11.88, and 6.34 points, respectively. Moreover, the preliminary internal validation efforts have demonstrated the practical application and clinical utility of these findings. With the exception of the distribution-based MCID of SF-36 PCS, which showed fair agreement, all other measures demonstrated moderate to almost perfect agreement.

CONCLUSIONS

The MDC, MCID, and SCB intuitively enhance the interpretation of VAS, AOFAS, and SF-36 in PCFD surgery, assisting all stakeholders to better understand the therapeutic benefits and limitations of clinical care, and thus to make a more rational decision. Each of these parameters has its own emphasis and complements the others. These parameters are recommended for evaluating the clinical relevance of the results, and their promotion should extend to other areas of foot and ankle surgery.

Socioeconomic disadvantage is correlated with worse PROMIS outcomes following lumbar fusion

BACKGROUND CONTEXT

Socioeconomic status (SES) has been associated with differential healthcare outcomes and may be proxied using the area-deprivation index (ADI). Few studies to date have investigated the role of ADI on patient-reported outcomes and clinically meaningful improvement following lumbar spine fusion surgery.

PURPOSE

The purpose of this study is to investigate the role of SES on lumbar fusion outcomes using Patient-Reported Outcomes Measurement Information System (PROMIS) surveys.

STUDY DESIGN/SETTING

Retrospective review of a single institution cohort.

PATIENT SAMPLE

About 205 patients who underwent elective one-to-three level posterior lumbar spine fusion.

OUTCOME MEASURES

Change in PROMIS scores and achievement of minimum clinically important difference (MCID).

METHODS

Patients 18 years or older undergoing elective one-to-three level lumbar spine fusion secondary to spinal degeneration from January 2015 to September 2021 with minimum one year follow-up were reviewed. ADI was calculated using patient-supplied addresses and patients were grouped into quartiles. Higher ADI values represent worse deprivation. Minimum clinically important difference (MCID) thresholds were calculated using distribution-based methods. Analysis of variance testing was used to assess differences within and between the quartile cohorts. Multivariable regression was used to identify features associated with the achievement of MCID.

RESULTS

About 205 patients met inclusion and exclusion criteria. The average age of our cohort was 66±12 years. The average time to final follow-up was 23±8 months (range 12-36 months). No differences were observed between preoperative baseline scores amongst the four quartiles. All ADI cohorts showed significant improvement for pain interference (PI) at final follow-up (p<.05), with patients who had the lowest socioeconomic status having the lowest absolute improvement from preoperative baseline physical function (PF) and PI (p=.01). Only those patients who were in the lowest socioeconomic quartile failed to significantly improve for PF at final follow-up (p=.19). There was a significant negative correlation between socioeconomic level and the absolute proportion of patients reaching MCID for PI (p=.04) and PF (p=.03). However, while ADI was a significant predictor of achieving MCID for PI (p=.02), it was nonsignificant for achieving MCID for PF.

CONCLUSIONS

Our study investigated the influence of ADI on postoperative PROMIS scores and identified a negative correlation between ADI quartile and the proportion of patients reaching MCID. Patients in the worse ADI quartile had lower chances of reaching clinically meaningful improvement in PI. Policies focused on alleviating geographical deprivation may augment clinical outcomes following lumbar surgery.

Effect of Baimai ointment on lumbar disc herniation: A multicentre, prospective, randomised, double-blind, placebo-controlled trial

BACKGROUND

Baimai ointment is a traditional Tibetan topical ointment, which is widely used for various diseases related to the skeletal muscular system and neurological rehabilitation. It has demonstrated good clinical effectiveness. However, there is currently a lack of high-quality evidence regarding the clinical effectiveness of Baimai ointment in treating lumbar disc herniation (LDH).

PURPOSE

In this study, we conducted a prospective, multicenter, double-blind, randomized controlled trial at eight hospitals in China to investigate the clinical effectiveness of Baimai ointment in the treatment of LDH.

METHODS

Participants aged 18-65 years were diagnosed as LDH and were randomly assigned to receive either Baimai ointment or placebo. The treatment duration was 2 weeks, with 1-week follow-up after treatment. The primary outcome measures included VAS and JOA score. The secondary outcome measures included Likert scale, compliance with health education and the incidence of rescue therapy. The intervention effects on these outcomes were examined by generalized estimating equations (GEE) with baseline measurement as the covariates. All statistical analysis were performed using SPSS 25.0 and Python 3.11.

RESULTS

In total, 228 participants were screened from August 25, 2021 to January 31, 2022 at 8 Grade-A tertiary hospitals in China. Finally, 194 eligible participants were randomly assigned to the Baimai ointment group and placebo group in a 1:1 ratio. At the end of 2-week treatment (14th day) and 1-week follow-up after treatment (21st day), the decrease of VAS reached 39.57% (95% CI: 34.29, 44.86) and 36.85% (95% CI: 32.04, 41.66), the decrease in JOA score reached 27.74% (95% CI: 23.05, 32.43) and 26.25 % (95% CI: 20.82, 31.69) in Baimai ointment group. A significant group-by-time interaction indicated a difference for VAS between intervention over time (χ2 = 26.81, p = 0.020), but JOA score and Likert scale did not reach statistical significance. The adjusted net difference of VAS was statistically significant from 10th day of treatment (p < 0.05). After 2-week treatment, the relief rate of VAS was 30.85% (21.95, 41.34) in Baimai ointment group and 22.73% (14.75, 33.13) in placebo group (χ2 = 1.53, p = 0.217). It demonstrated Baimai ointment in improving VAS and JOA score was valuable from a clinical view by measuring MCID. Moreover, the Likert scale, the incidence of rescue therapy and compliance with health education did not reach statistical significance. There was no evidence showing that Baimai ointment could cause serious adverse reactions in treating patients with LDH.

CONCLUSION

Baimai ointment demonstrated significantly higher rates of symptom relief compared to the placebo for LDH patients, particularly in terms of relieving pain. Moreover, further high-quality randomized controlled trials were necessary to confirm these positive results. The study protocol is registered with the Clinical Trials Registry (registration number: ISRCTN11912818).

Preoperative Disability Influences Effectiveness of MCID and PASS in Predicting Patient Improvement Following Lumbar Spine Surgery

STUDY DESIGN

Retrospective cohort.

SUMMARY OF BACKGROUND DATA

Although minimal clinically important difference (MCID) and patient acceptable symptom state (PASS) are utilized to interpret Oswestry Disability Index (ODI), it is unclear whether there is a clearly better metric between the two and if not, which metric should be utilized when.

OBJECTIVE

To compare the characteristics of MCID and PASS when interpreting ODI after lumbar spine surgery.

METHODS

Patients who underwent primary minimally invasive transforaminal lumbar interbody fusion or decompression were included. The ODI and global rating change data at 1 year were analyzed. The global rating change was collapsed to a dichotomous outcome variable-(a) improved, (b) not improved The sensitivity, specificity, positive predictive value and negative predictive value of MCID and PASS were calculated for the overall cohort and separately for patients with minimal, moderate, and severe preoperative disability. Two groups with patients who achieved PASS but not MCID and patients who achieved MCID but not PASS were analyzed.

RESULTS

Two hundred twenty patients (mean age 62 y, 57% males) were included. PASS (86% vs. 69%) and MCID (88% vs. 63%) had significantly greater sensitivity in patients with moderate and severe preoperative disability, respectively. Nineteen percent of patients achieved PASS but not MCID and 10% of patients achieved MCID but not PASS, with the preoperative ODI being significantly greater in the latter. Most of these patients still reported improvement with no significant difference between the 2 groups (93% vs. 86%).

CONCLUSION

Significant postoperative clinical improvement is most effectively assessed by PASS in patients with minimal or moderate preoperative disability and by MCID in patients with severe preoperative disability. Adequate interpretation of ODI using the PASS and MCID metrics warrants individualized application as their utility is highly dependent on the degree of preoperative disability.

An Evaluation of Patient-reported Outcome Measures and Minimal Clinically Important Difference Usage in Hand Surgery

Background

This study was designed to examine the current use of patient-reported outcome measures (PROMs) and minimal clinically important difference (MCID) calculations in the hand surgery literature in an effort to standardize their use for research purposes.

Methods

A systematic review of the hand surgery literature was conducted. All nonshoulder upper extremity articles utilizing PROMs were compared between different journals, different surgical indications, and differing usage. MCID values were reported, and calculation methods assessed.

Results

In total, 4677 articles were reviewed, and 410 met the inclusion criteria of containing at least one PROM. Of the 410 articles reporting PROMs, 148 also mentioned an associated MCID. Of the articles that mentioned MCIDs, 14 calculated MCID values based on their specific clinical populations, whereas the remainder referenced prior studies. An estimated 35 different PROMs were reported in the study period; 95 different MCID values were referenced from 65 unique articles.

Conclusions

There are many different PROMs currently being used in hand surgery clinical reports. The reported MCIDs from their related PROMs are from multiple different sources and calculated by different methods. The lack of standardization in the hand surgery literature makes interpretation of studies utilizing PROMs difficult. There is a need for a standardized method of calculating MCID values and applying these values to established PROMs for nonshoulder upper extremity conditions.

Optimizing percutaneous vertebroplasty: extra-facet puncture for osteoporotic vertebral compression fractures

PURPOSE

To assess the safety and efficacy of the extra-facet puncture technique applied in unilateral percutaneous vertebroplasty (PVP) for treating osteoporotic vertebral compression fractures.

METHODS

Demographics (age, gender, body mass index and underlying diseases) were recorded for analyzing. Visual analog scale (VAS) and Oswestry Disability Index (ODI) scores as well as their corresponding minimal clinically important difference (MCID) were used to evaluate clinical outcomes. The segmental kyphotic angle, the vertebral compression ratio and bone cement distribution pattern were evaluated by the plain radiographs. The facet joint violation (FJV) was defined by the postoperative computed tomography scan. Binary logistic regression analysis was performed to investigate relationships between multiple risk factors and residual back pain.

RESULTS

VAS and ODI scores in both traditional puncture group and extra-facet puncture group were significantly decreased after PVP surgery (p < 0.05). However, no significant difference was observed between the two groups according to VAS and ODI scores. The proportion of patients achieving MCID of VAS and ODI scores was higher in extra-facet puncture group as compared to traditional puncture group within a month (p < 0.05). Finally, multivariate logistic regression analysis showed that FJV (odds ratio 16.38, p < 0.001) and unilateral bone cement distribution (OR 5.576, p = 0.020) were significant predictors of residual back pain after PVP surgery.

CONCLUSIONS

Extra-facet puncture percutaneous vertebroplasty can decrease the risk of FJV and it also has the advantage of more satisfied bone cement distribution.

Adherence to the Obeid coronal malalignment classification and a residual malalignment below 20 mm can improve surgical outcomes in adult spine deformity surgery

PURPOSE

Coronal balance is a major factor impacting the surgical outcomes in adult spinal deformity (ASD). The Obeid coronal malalignment (O-CM) classification has been proposed to improve the coronal alignment in ASD surgery. Aim of this study was to investigate whether a postoperative CM < 20 mm and adherence to the O-CM classification could improve surgical outcomes and decrease the rate of mechanical failure in a cohort of ASD patients.

METHODS

Multicenter retrospective analysis of prospectively collected data on all ASD patients who underwent surgical management and had a preoperative CM > 20 mm and a 2-year follow-up. Patients were divided in two groups according to whether or not surgery had been performed in adherence to the guidelines of the O-CM classification and according to whether or not the residual CM was < 20 mm. The outcomes of interest were radiographic data, rate of mechanical complications and Patient-Reported Outcome Measures.

RESULTS

At 2 years, adherence to the O-CM classification led to a lower rate of mechanical complications (40 vs. 60%). A coronal correction of the CM < 20 mm allowed for a significant improvement in SRS-22 and SF-36 scores and was associated with a 3.5 times greater odd of achieving the minimal clinical important difference for the SRS-22.

CONCLUSION

Adherence to the O-CM classification could reduce the risk of mechanic complications 2 years after ASD surgery. Patients with a residual CM < 20 mm showed better functional outcomes and a 3.5 times greater odd of achieving the MCID for the SRS-22 score.

Values derived from patient reported outcomes in spine surgery: a systematic review of the minimal clinically important difference, substantial clinical benefit, and patient acceptable symptom state

PURPOSE

While patient reported outcome measures (PROMs) define value in spine surgery, several values such as minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptom state (PASS) help guide the interpretation of PROMs and identify thresholds of clinical significance. Significant variation exists in reported values and their calculation, so the primary objective of this study was to systematically review the spine surgery literature for metrics of clinical significance derived from PROMs.

METHODS

We conducted a query of PubMed/MEDLINE and Scopus databases from inception to January 1, 2023, for studies that derived quantitative metrics (e.g., SCB, MCID, PASS) from PROMs in the setting of spine surgery with minimum 1-year follow-up. Details regarding the specific PROMs were collected including which PROM was measured, whether anchor- or distribution-based methods were utilized, the specific calculations, and the recommended value for a given PROM based on all evaluated calculations.

RESULTS

Thirty-seven studies of 21,780 patients were included. The most commonly evaluated PROM-derived value was the MCID (n = 28), followed by PASS (n = 6) and SCB (n = 4). Twenty-one studies only utilized anchor-based calculations, 15 utilized both anchor-based and distribution-based methods, and one only utilized distribution-based calculations. The most commonly evaluated legacy PROMs were the Oswestry Disability Index (ODI) (N = 11, MCID range 4-20) and visual analog scale back pain (N = 5, MCID range 0.5-4.6). All 10 studies that derived SCB or PASS utilized the receiver operating characteristic methods. Among the six studies deriving a PASS value, four only evaluated ODI, identifying PASS ranging from 5 to 22.

CONCLUSION

While calculated measures of clinical significance such as MCID, PASS, and SCB exist, significant heterogeneity exists in the current literature. Current shortcomings include a wide variability of reported value thresholds across the literature, and limited applicability to more heterogenous patient populations than the targeted cohorts included in published investigations. Continued investigations that apply these methods to heterogenous, large-scale populations can help increase generalizability and validity of these measures.

LEVEL OF EVIDENCE

III.

Quality of Life and Postoperative Satisfaction in Patients with Benign Extramedullary Spinal Tumors: A Multicenter Study

STUDY DESIGN

Retrospective cohort study using prospectively collected registry data.

OBJECTIVE

The purpose of this study is to evaluate health-related quality of life (HRQOL) and postoperative satisfaction in patients with different histotypes of benign extramedullary spinal tumors (ESTs).

BACKGROUND

Little is known about how different histotypes influence HRQOL and postoperative satisfaction in EST patients.

MATERIALS AND METHODS

Patients undergoing primary benign EST surgery at 11 tertiary referral hospitals between 2017 and 2021 who completed preoperative and 1-year postoperative questionnaires were included. HRQOL assessment included the Physical Component Summary and Mental Component Summary (MCS) of Short Form-12, EuroQol 5-dimension, Oswestry/Neck Disability Index (ODI/NDI), and Numeric Rating Scales (NRS) for upper/lower extremities (UEP/LEP) and back pain (BP). Patients who answered "very satisfied," "satisfied," or "somewhat satisfied" on a seven-point Likert scale were considered to be satisfied with treatment. Student t -tests or Welch's t -test were used to compare continuous variables between two groups, and one-way analysis of variance was used to compare outcomes between the three groups of EST histotypes (schwannoma, meningioma, atypical). Categorical variables were compared using the χ 2 test or Fisher exact test.

RESULTS

A total of 140 consecutive EST patients were evaluated; 100 (72%) had schwannomas, 30 (21%) had meningiomas, and 10 (7%) had other ESTs. Baseline Physical Component Summary was significantly worse in patients with meningiomas ( P =0.04), and baseline NRS-LEP was significantly worse in patients with schwannomas ( P =0.03). However, there were no significant differences in overall postoperative HRQOL or patient satisfaction between histology types. Overall, 121 (86%) patients were satisfied with surgery. In a subgroup analysis comparing intradural schwannomas and meningiomas adjusted for patient demographics and tumor location with inverse probability weighting, schwannoma patients had worse baseline MCS ( P =0.03), ODI ( P =0.03), NRS-BP ( P <.001), and NRS-LEP ( P =0.001). Schwannoma patients also had worse postoperative MCS ( P =0.03) and NRS-BP ( P =0.001), with no significant difference in the percentage of satisfied patients ( P =0.30).

CONCLUSIONS

Patients who underwent primary benign EST resection had a significant improvement in HRQOL postoperatively, and ~90% of these patients reported being satisfied with their treatment outcomes one year after surgery. EST patients may exhibit a relatively lower threshold for postoperative satisfaction compared with patients undergoing surgery for degenerative spine conditions.

Time to achievement of minimum clinically important difference after lumbar decompression

OBJECTIVE

The objective of this study is to examine factors associated with delayed time to achieve minimum clinically important difference (MCID) in patients undergoing lumbar decompression (LD) for the Patient-Reported Outcomes (PROs) of Oswestry Disability Index (ODI), Visual Analog Scale (VAS) back, and VAS leg pain.

METHODS

Patients undergoing LD with preoperative and postoperative ODI, VAS back, and VAS leg scores were retrospectively reviewed from April 2016 to January 2021. MCID values from previously established studies were utilized to determine MCID achievement. Kaplan-Meier survival analysis determined the time to achieve MCID. Hazard ratios from multivariable Cox regression were utilized to determine the preoperative factors predictive of MCID achievement.

RESULTS

Three-hundred and forty-three patients were identified undergoing LD. Overall MCID achievement rates were 67.4% for ODI, 67.1% for VAS back, and 65.0% for VAS leg. The mean time in weeks for MCID achievement was 22.52 ± 30.48 for ODI, 18.90 ± 27.43 for VAS back, and 20.96 ± 29.81 for VAS leg. Multivariable Cox regression revealed active smoker status, preoperative Patient-Reported Outcomes Measurement Information System Physical Function (PROMIS-PF), ODI, VAS Back, and VAS Leg (HR 1.03-2.14) as predictors of early MCID achievement, whereas an American Society of Anesthesiologist (ASA) classification of 2, Black ethnicity, workers' compensation, private insurance, and diagnosis of foraminal stenosis were predictors of late MCID achievement (HR 0.34-0.58).

CONCLUSION

Most patients undergoing LD achieved MCID within 6 months of surgery. Significant factors for early MCID achievement were active smoking status and baseline PROs. Significant factors for late MCID achievement were ASA = 2, Black ethnicity, type of insurance, and foraminal stenosis diagnosis. These factors may be considered by surgeons in setting patient expectations.

What are the Minimum Clinically Important Difference Values for the PROMIS and QuickDASH After Carpal Tunnel Release? A Prospective Cohort Study

BACKGROUND

To better define the clinical significance of patient-reported outcomes, the concept of a minimum clinically important difference (MCID) exists. The MCID is the minimum change that a patient will perceive as meaningful. Prior attempts to determine the MCID after carpal tunnel release are limited by methodologic concerns, including the lack of a true anchor-based MCID calculation.

QUESTIONS/PURPOSES

To address previous methodologic concerns in existing studies, as well as establish a clinically useful value for clinicians, we asked: What are the MCID values for the Patient-Reported Outcomes Measurement Information System (PROMIS) Upper Extremity (UE), PROMIS Pain Interference (PI), and the QuickDASH after carpal tunnel release?

METHODS

We conducted a prospective cohort study at an urban, Midwest, multihospital, academic health system. One hundred forty-seven adult patients undergoing unilateral carpal tunnel release between September 2020 and February 2022 were identified. PROMIS UE, PI, and QuickDASH scores were collected preoperatively and 3 months postoperatively. We also collected responses to an anchor-based question: "Since your treatment, how would you rate your overall function?" (much worse, worse, slightly worse, no change, slightly improved, improved, or much improved). Patients who did not respond to the 3-month postoperative surveys were excluded. A total of 122 patients were included in the final analysis (83% response proportion [122 of 147]). The mean age was 57 years (range 23 to 87 years), and 68% were women. The MCID was calculated using both anchor-based and distribution-based methods. Although anchor-based calculations are generally considered more clinically relevant because they consider patients' perceptions of improvement, an estimation of the minimum detectable change (which represents measurement error) relies on a distribution-based calculation. We determined a range of MCID values to propose a final MCID value for all three instruments. A negative MCID value for the PROMIS PI instrument represents a decrease in pain, whereas a positive value for the PROMIS UE instrument represents an improvement in function. A negative value for the QuickDASH instrument represents an increase in function.

RESULTS

The final proposed MCID values were 6.2 (interquartile range [IQR] 5.4 to 9.0) for the PROMIS UE, -7.8 (IQR -6.1 to -8.5) for the PROMIS PI, and -18.2 (IQR -13.3 to -34.1) for the QuickDASH.

CONCLUSION

We recommend that clinicians use the following values as the MCID after carpal tunnel release: 6 for the UE, -8 for the PI, and -18 for the QuickDASH. Surgeons may find these values useful when counseling patients postoperatively regarding improvement. Future studies could examine whether a single MCID (or small range) for PROMIS instruments is applicable to a variety of conditions and interventions.

LEVEL OF EVIDENCE

Level II, therapeutic study.

Preoperative patient activation predicts minimum clinically important difference for PROMIS pain and physical function in patients undergoing elective spine surgery

BACKGROUND CONTEXT

Patient activation is a patient's willingness to take independent actions to manage their own health care.

PURPOSE

The goal of this study is to determine whether preoperative patient activation measure (PAM) predicts minimum clinically important difference (MCID) for Patient-Reported Outcomes Measurement Information System (PROMIS) pain, physical function, depression, and anxiety for patients undergoing elective spine surgery.

STUDY DESIGN/SETTING

Retrospective review.

PATIENT SAMPLE

A single-institution, academic database of patients undergoing elective spine surgery.

OUTCOME MEASURE

MCID at 1-year follow-up for PROMIS pain, physical function, depression and anxiety.

METHODS

We retrospectively reviewed a single-institution, academic database of patients undergoing elective spine surgery. Preoperative patient activation was evaluated using the PAM-13 survey, which was used to stratify patients into four activation stages. Primary outcome variable was achieving MCID at 1-year follow-up for PROMIS pain and physical function. Multivariable logistic regression analysis was used to determine impact of patient activation on PROMIS pain and the physical function.

RESULTS

Of the 430 patients, 220 (51%) were female with a mean age of 58.2±16.8. Preoperatively, 34 (8%) were in activation stage 1, 45 (10%) in stage 2, 98 (23%) in stage 3, and 253 (59%) in stage 4. At 1-year follow up, 248 (58%) achieved MCID for PROMIS physical function, 256 (60%) achieved MCID for PROMIS pain, 151 (35.28%) achieved MCID for PROMIS depression, and 197 (46%) achieved MCID for PROMIS anxiety. For PROMIS physical function, when compared to patients at stage 1 activation, patients at stage 2 (aOR:3.49, 95% CI:1.27, 9.59), stage 3 (aOR:3.54, 95% CI:1.40, 8.98) and stage 4 (aOR:7.88, 95% CI:3.29, 18.9) were more likely to achieve MCID. For PROMIS pain, when compared against patients at stage 1, patients at stage 3 (aOR:2.82, 95% CI:1.18, 6.76) and stage 4 (aOR:5.44, 95% CI:2.41, 12.3) were more likely to achieve MCID. For PROMIS depression, when compared against patients at stage 1, patients at stage 4 were more likely to achieve MCID (Adjusted Odds Ratio (aOR):2.59, 95% CI:1.08-6.19). For PROMIS anxiety, when compared against patients at stage 1, stage 3 (Adjusted Odds Ratio (aOR):3.21, 95% CI:1.20-8.57), and stage 4 (aOR:5.56, 95% CI:2.20-14.01) were more likely to achieve MCID.

CONCLUSION

Patients at higher stages of activation were more likely to achieve MCID for PROMIS pain, physical function, depression, and anxiety at 1-year follow-up. Routine preoperative assessment of patient activation may help identify patients at risk of poor outcomes.

Minimal clinically important difference as a method for assessing the effectiveness of spinal surgery using scales and questionnaires: non-systematic literature review

Objective. To analyze the literature data and to present recommendations on the use of the minimum clinically important difference (MCID) in the practice of spinal surgeon-researcher.

Material and Methods. The article is a non-systematic review of the literature. A search was performed for sources, which describe the calculation and analysis of the MCID parameter on a cohort of patients with degenerative spinal diseases in the PubMed, Scopus and Web of Science databases. Further, the analysis of the literature was carried out on the application of MCID to assess the effectiveness of surgical treatment.

Results. The MCID parameter is illustrated for the most common clinical scales used to assess the effectiveness of treatment in spinal surgery, with their detailed description and discussion of their benefits and drawbacks. The specific MCID values for cervical and lumbar pathologies, first of all degenerative ones, and follow-up periods, which can be used in assessing the results of the treatment, as well as in planning prospective comparative studies are presented.

Conclusion. The MCID parameter is required for sample size calculation and for the analysis of treatment outcomes. The MCID reflects not just the change in the baseline indicator, but also the clinical significance for the patient.

Yoga for chronic non-specific low back pain

BACKGROUND

Non-specific low back pain is a common, potentially disabling condition usually treated with self-care and non-prescription medication. For chronic low back pain, current guidelines recommend exercise therapy. Yoga is a mind-body exercise sometimes used for non-specific low back pain.

OBJECTIVES

To evaluate the benefits and harms of yoga for treating chronic non-specific low back pain in adults compared to sham yoga, no specific treatment, a minimal intervention (e.g. education), or another active treatment, focusing on pain, function, quality of life, and adverse events.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was 31 August 2021 without language or publication status restrictions.

SELECTION CRITERIA

We included randomized controlled trials of yoga compared to sham yoga, no intervention, any other intervention and yoga added to other therapies.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methods. Our major outcomes were 1. back-specific function, 2. pain, 3. clinical improvement, 4. mental and physical quality of life, 5. depression, and 6.

ADVERSE EVENTS

Our minor outcome was 1. work disability. We used GRADE to assess certainty of evidence for the major outcomes.

MAIN RESULTS

We included 21 trials (2223 participants) from the USA, India, the UK, Croatia, Germany, Sweden, and Turkey. Participants were recruited from both clinical and community settings. Most were women in their 40s or 50s. Most trials used iyengar, hatha, or viniyoga yoga. Trials compared yoga to a non-exercise control including waiting list, usual care, or education (10 trials); back-focused exercise such as physical therapy (five trials); both exercise and non-exercise controls (four trials); both non-exercise and another mind-body exercise (qigong) (one trial); and yoga plus exercise to exercise alone (one trial). One trial comparing yoga to exercise was an intensive residential one-week program, and we analyzed this trial separately. All trials were at high risk of performance and detection bias because participants and providers were not blinded to treatment, and outcomes were self-assessed. We found no trials comparing yoga to sham yoga. Low-certainty evidence from 11 trials showed that there may be a small clinically unimportant improvement in back-specific function with yoga (mean difference [MD] -1.69, 95% confidence interval [CI] -2.73 to -0.65 on the 0- to 24-point Roland-Morris Disability Questionnaire [RMDQ], lower = better, minimal clinically important difference [MCID] 5 points; 1155 participants) and moderate-certainty evidence from nine trials showed a clinically unimportant improvement in pain (MD -4.53, 95% CI -6.61 to -2.46 on a 0 to 100 scale, 0 no pain, MCID 15 points; 946 participants) compared to no exercise at three months. Low-certainty evidence from four trials showed that there may be a clinical improvement with yoga (risk ratio [RR] 2.33, 95% CI 1.46 to 3.71; assessed as participant rating that back pain was improved or resolved; 353 participants). Moderate-certainty evidence from six trials showed that there is probably a small improvement in physical and mental quality of life (physical: MD 1.80, 95% CI 0.27 to 3.33 on the 36-item Short Form [SF-36] physical health scale, higher = better; mental: MD 2.38, 95% CI 0.60 to 4.17 on the SF-36 mental health scale, higher = better; both 686 participants). Low-certainty evidence from three trials showed little to no improvement in depression (MD -1.25, 95% CI -2.90 to 0.46 on the Beck Depression Inventory, lower = better; 241 participants). There was low-certainty evidence from eight trials that yoga increased the risk of adverse events, primarily increased back pain, at six to 12 months (RR 4.76, 95% CI 2.08 to 10.89; 43/1000 with yoga and 9/1000 with no exercise; 1037 participants). For yoga compared to back-focused exercise controls (8 trials, 912 participants) at three months, we found moderate-certainty evidence from four trials for little or no difference in back-specific function (MD -0.38, 95% CI -1.33 to 0.62 on the RMDQ, lower = better; 575 participants) and very low-certainty evidence from two trials for little or no difference in pain (MD 2.68, 95% CI -2.01 to 7.36 on a 0 to 100 scale, lower = better; 326 participants). We found very low-certainty evidence from three trials for no difference in clinical improvement assessed as participant rating that back pain was improved or resolved (RR 0.97, 95% CI 0.72 to 1.31; 433 participants) and very low-certainty evidence from one trial for little or no difference in physical and mental quality of life (physical: MD 1.30, 95% CI -0.95 to 3.55 on the SF-36 physical health scale, higher = better; mental: MD 1.90, 95% CI -1.17 to 4.97 on the SF-36 mental health scale, higher = better; both 237 participants). No studies reported depression. Low-certainty evidence from five trials showed that there was little or no difference between yoga and exercise in the risk of adverse events at six to 12 months (RR 0.93, 95% CI 0.56 to 1.53; 84/1000 with yoga and 91/1000 with non-yoga exercise; 640 participants).

AUTHORS' CONCLUSIONS

There is low- to moderate-certainty evidence that yoga compared to no exercise results in small and clinically unimportant improvements in back-related function and pain. There is probably little or no difference between yoga and other back-related exercise for back-related function at three months, although it remains uncertain whether there is any difference between yoga and other exercise for pain and quality of life. Yoga is associated with more adverse events than no exercise, but may have the same risk of adverse events as other exercise. In light of these results, decisions to use yoga instead of no exercise or another exercise may depend on availability, cost, and participant or provider preference. Since all studies were unblinded and at high risk of performance and detection bias, it is unlikely that blinded comparisons would find a clinically important benefit.

Determination of Patient Acceptable Symptom State for the Oswestry Disability Index Score in Patients Who Underwent Minimally Invasive Discectomy for Lumbar Disc Herniation: 2-Year Follow-up Data from a Randomized Controlled Trial

OBJECTIVE

We aim to determinate the patient acceptable symptom state (PASS) for the Oswestry Disability Index (ODI) score in patients undergoing minimally invasive discectomy for the treatment of lumbar disc herniation.

METHODS

A post hoc analysis of prospectively collected, 2-year follow-up data was conducted. The anchor for determination of PASS was the European Quality of Life Visual Analog Scales question, and the Pearson correlation test was performed to evaluate its validity. The receiver operating characteristics (ROC) curve analysis was conducted to determine the PASS thresholds for ODI and its discriminative ability assessment. Sensitivity analyses were also carried out for alternative definition of PASS, different follow-up periods, and different subgroups.

RESULTS

A total of 222 patients (92.1%) completed the 2-year follow-up, 92.8% of whom considered their state to be acceptable. The area under the ROC curve (AUC) were all >0.8, indicating a high discriminative ability. The PASS threshold for the ODI was suggested to be 5 at 6 months (AUC: 0.80; sensitivity: 79.0%, specificity: 73.7%) and 2 years (AUC: 0.98; sensitivity: 90.3%, specificity: 100%) postoperatively. Despite some variations found in different body mass index and baseline ODI subgroups, sensitivity analysis showed that the above-mentioned threshold was robust.

CONCLUSIONS

An ODI of 5 was noted to be the PASS threshold for patients received minimally invasive discectomy for the treatment of LDH. This ODI threshold was robust, and therefore recommended as the ultimate goal of minimally invasive treatment for LDH, which can help to present results of clinical research at an individual level.

Back Dominant Pain Has Equal Outcomes to Radicular Dominant Pain Following Posterior Lumbar Fusion in Adult Isthmic Spondylolisthesis: A CSORN Study

STUDY DESIGN

Retrospective Cohort Study.

OBJECTIVES

This study aimed to determine how the surgeon-determined and patient-rated location of predominant pain influences patient-rated outcomes at 1-year after posterior lumbar fusion in adult isthmic spondylolisthesis.

METHODS

We retrospectively reviewed consecutive patients prospectively enrolled in the Canadian Spine Outcomes and Research Network national registry between 2009 and 2017 that underwent posterior lumbar fusion for isthmic spondylolisthesis. Using longitudinal mixed-model repeated-measures analysis the change from baseline in patient-reported outcome measures (PROMs) at 1 year after surgery was compared between surgeon-determined groups (back vs. radicular) and between patient-rated pain groups (back, leg, and equal) derived from preoperative pain scores on the numerical rating scale (NRS).

RESULTS

83/252 (33%) patients had a surgeon-determined chief complaint of back pain, while 103 (41%) patients rated their back pain as the predominant pain location, and 78 (31%) rated their back and leg pain to be equal. At baseline patients in the surgeon-determined radicular group had worse NRS-leg pain than those in the back-pain group but equal NRS-back pain. At baseline patients in the patient-rated equal pain group had similar back pain compared to the patient-rated back pain group and similar leg pain compared to the patient-rated leg pain group. All PROMs improved post-operatively and were not different between the 2 groups at 1 year.

CONCLUSIONS

Our study found no difference in outcome, irrespective of whether a surgeon determines the patient's primary pain complaint back or radicular dominant, or the patient rates pain in one location greater than another.

Surgical outcomes of patients who fail to reach minimal clinically important differences: comparison of minimally invasive versus open transforaminal lumbar interbody fusion

OBJECTIVE

Treatment of degenerative lumbar diseases has been shown to be clinically effective with open transforaminal lumbar interbody fusion (O-TLIF) or minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF). Despite this, a substantial proportion of patients do not meet minimal clinically important differences (MCIDs) in patient-reported outcomes (PROs). The objectives of this study were to compare the proportions of patients who did not meet MCIDs after O-TLIF and MIS-TLIF and to determine potential clinical factors associated with failure to achieve MCID.

METHODS

The authors performed a retrospective analysis of consecutive patients who underwent O-TLIF or MIS-TLIF for lumbar degenerative disorders and had been prospectively enrolled in the Canadian Spine Outcomes and Research Network. The authors analyzed the Oswestry Disability Index (ODI) scores, physical and mental component summary scores of SF-12, numeric rating scale (NRS) scores for leg and back pain, and EQ-5D scores of the patients in each group who did not meet the MCID of ODI at 2 years postoperatively.

RESULTS

In this study, 38.8% (137 of 353) of patients in the O-TLIF cohort and 41.8% (51 of 122) of patients in the MIS-TLIF cohort did not meet the MCID of ODI at 2 years postoperatively (p = 0.59). Demographic variables and baseline PROs were similar between groups. There were improvements across the PROs of both groups through 2 years, and there were no differences in any PROs between the O-TLIF and MIS-TLIF cohorts. Multivariable logistic regression analysis demonstrated that higher baseline leg pain score (p = 0.017) and a diagnosis of spondylolisthesis (p = 0.0053) or degenerative disc disease (p = 0.022) were associated with achieving the MCID at 2 years after O-TLIF, whereas higher baseline leg pain score was associated with reaching the MCID after MIS-TLIF (p = 0.038).

CONCLUSIONS

Similar proportions of patients failed to reach the MCID of ODI at 2 years after O-TLIF or MIS-TLIF. Higher baseline leg pain score was predictive of achieving the MCID in both cohorts, whereas a diagnosis of spondylolisthesis or degenerative disc disease was predictive of reaching the MCID after O-TLIF. These data provide novel insights for patient counseling and suggest that either MIS-TLIF or O-TLIF does not overcome specific patient factors to mitigate clinical success or failure in terms of the intermediate-term PROs associated with 1- to 2-level lumbar fusion surgical procedures for degenerative pathologies.

An assessment of the minimal clinically important difference for the pain disability quality-of-Life Questionnaire-Spine

Objective

The Pain Disability Quality-Of-Life Questionnaire-Spine (PDQQ-S) is a validated six question patient reported outcome measure designed for usage in minimally invasive spine intervention. The purpose of this study was to determine the Minimal Clinically Important Difference (MCID) for the PDQQ-S.

Design

Retrospective single arm cohort study involving 411 patients who had undergone lumbar facet and/or sacroiliac joint RFN and had completed pre-and 3-month post RFN PDQQ-S.

Methods

The MCID using both distribution and anchor-based ("Rebook RFN"; "Analgesic Requirements") methods were calculated.

Results

The distribution-based approach (using standard error of measurement) estimated the MCID to be -17.3 [PDQQ-S baseline mean (SD): 46.9 (7.9)]. This is supported by the anchor based approach, which calculated the MCID to be: -21.5 for rebook RFN; -11.3, -17.2 and -30.5 for mildly, moderately and dramatically decreased NSAID use respectively; and -11.7, -16.9 and -31.7 for mildly, moderately and dramatically decreased opioid use respectively. A moderate reduction in medication use was deemed to be clinically relevant.

Conclusion

The MCID value for the PDQQ-S is a score reduction of 17.

The minimal important change for the EQ VAS based on the SF-36 health transition item: observations from 25772 spine surgery procedures

PURPOSE

The EQ VAS is an integral part of EQ-5D, a commonly used instrument for health-related quality of life assessment. This study aimed to calculate the minimal important change (MIC) thresholds for the EQ VAS for improvement and deterioration after surgery for disk herniation or spinal stenosis.

METHODS

Patients, who were surgically treated for disk herniation or spinal stenosis between 2007 and 2016, were recruited from the Swedish spine register. Preoperative and 1-year postoperative data for a total of 25772 procedures were available for analysis. We used two anchor-based methods to estimate MIC for EQ VAS: (1) a predictive model based on logistic regression and (2) receiver operating characteristics (ROC) curves. The SF-36 health transition item was used as anchor.

RESULTS

The EQ VAS MIC threshold for improvement after disk herniation surgery ranged from 8.25 to 11.8 while the corresponding value for deterioration ranged from - 6.17 to 0.5. For spinal stenosis surgery the corresponding MIC values ranged from 10.5 to 14.5 and - 7.16 to - 6.5 respectively. There were moderate negative correlations (disk herniation - 0.47, spinal stenosis - 0.46) between the 1 year change in the EQ VAS and the SF-36 health transition item (MIC anchor).

CONCLUSIONS

For EQ VAS, we recommend a MIC threshold of 12 points for improvement after surgery for disk herniation or spinal stenosis, whereas the corresponding threshold for deterioration is - 7 points. There are marked differences between the EQ VAS MIC for improvement and deterioration after surgery for disk herniation or spinal stenosis. The MIC value varied depending on the method used for MIC estimation.

Impetus of US hospital leaders to invest in patient-reported outcome measures (PROMs): a qualitative study

OBJECTIVES

Though hospital leaders across the USA have invested significant resources in collection of patient-reported outcome measures (PROMs), there are very limited data on the impetus for hospital leadership to establish PROM programmes. In this qualitative study, we identify the drivers and motivators of PROM collection among hospital leaders in the USA.

DESIGN

Exploratory qualitative study.

SETTING

Thirty-seven hospital leaders representing seven different institutions with successful PROMs programs across twenty US states.

METHODS

Semistructured interviews conducted with hospital leaders. Transcripts were analysed using thematic analysis.

RESULTS

Leaders strongly believe that collecting PROMs is the 'right thing to do' and that the culture of the institution plays an important role in enabling PROMs. The study participants often believe that their institutions deliver superior care and that PROMs can be used to demonstrate the value of their services to payors and patients. Direct financial incentives are relatively weak motivators for collection of PROMs. Most hospital leaders have reservations about using PROMs in their current state as a meaningful performance metric.

CONCLUSION

These findings suggest that hospital leaders feel a strong moral imperative to collect PROMs, which is also supported by the culture of their institution. Although PROMs are used in negotiations with payors, direct financial return on investment is not a strong driver for the collection of PROMs. Understanding why leaders of major healthcare institutions invest in PROMs is critical to understanding the role that PROMs play in the US healthcare system.

Substantial Inconsistency and Variability Exists Among Minimum Clinically Important Differences for Shoulder Arthroplasty Outcomes: A Systematic Review

BACKGROUND

As the value of patient-reported outcomes becomes increasingly recognized, minimum clinically important difference (MCID) thresholds have seen greater use in shoulder arthroplasty. However, MCIDs are unique to certain populations, and variation in the modes of calculation in this field may be of concern. With the growing utilization of MCIDs within the field and value-based care models, a detailed appraisal of the appropriateness of MCID use in the literature is necessary and has not been systematically reviewed.

QUESTIONS/PURPOSES

We performed a systematic review of MCID quantification in existing studies on shoulder arthroplasty to answer the following questions: (1) What is the range of values reported for the MCID in commonly used shoulder arthroplasty patient-reported outcome measures (PROMs)? (2) What percentage of studies use previously existing MCIDs versus calculating a new MCID? (3) What techniques for calculating the MCID were used in studies where a new MCID was calculated?

METHODS

The Embase, PubMed, and Ovid/MEDLINE databases were queried from December 2008 through December 2020 for total shoulder arthroplasty and reverse total shoulder arthroplasty articles reporting an MCID value for various PROMs. Two reviewers (DAK, MAM) independently screened articles for eligibility, specifically identifying articles that reported MCID values for PROMs after shoulder arthroplasty, and extracted data for analysis. Each study was classified into two categories: those referencing a previously defined MCID and those using a newly calculated MCID. Methods for determining the MCID for each study and the variability of reported MCIDs for each PROM were recorded. The number of patients, age, gender, BMI, length of follow-up, surgical indications, and surgical type were extracted for each article. Forty-three articles (16,408 patients) with a mean (range) follow-up of 20 months (0.75 to 68) met the inclusion criteria. The median (range) BMI of patients was 29.3 kg/m2 (28.0 to 32.2 kg/m2), and the median (range) age was 68 years (53 to 84). There were 17 unique PROMs with MCID values. Of the 112 MCIDs reported, the most common PROMs with MCIDs were the American Shoulder and Elbow Surgeons (ASES) (23% [26 of 112]), the Simple Shoulder Test (SST) (17% [19 of 112]), and the Constant (15% [17 of 112]).

RESULTS

The ranges of MCID values for each PROM varied widely (ASES: 6.3 to 29.5; SST: 1.4 to 4.0; Constant: -0.3 to 12.8). Fifty-six percent (24 of 43) of studies used previously established MCIDs, with 46% (11 of 24) citing one study. Forty-four percent (19 of 43) of studies established new MCIDs, and the most common technique was anchor-based (37% [7 of 19]), followed by distribution (21% [4 of 19]).

CONCLUSION

There is substantial inconsistency and variability in the quantification and reporting of MCID values in shoulder arthroplasty studies. Many shoulder arthroplasty studies apply previously published MCID values with variable ranges of follow-up rather than calculating population-specific thresholds. The use of previously calculated MCIDs may be acceptable in specific situations; however, investigators should select an anchor-based MCID calculated from a patient population as similar as possible to their own. This practice is preferable to the use of distribution-approach MCID methods. Alternatively, authors may consider using substantial clinical benefit or patient-acceptable symptom state to assess outcomes after shoulder arthroplasty.

CLINICAL RELEVANCE

Although MCIDs may provide a useful effect-size based alternative to the traditional p value, care must be taken to use an MCID that is appropriate for the particular patient population being studied.

Minimal clinically important difference in patients who underwent decompression alone for lumbar degenerative disease

BACKGROUND CONTEXT

The minimal clinically important difference (MCID) represents the smallest change in an outcome measure recognized as clinically meaningful to a patient after receiving a clinical intervention. Most studies that discussed the MCIDs for lumbar spinal stenosis (LSS) included mixed pathologies or procedures despite that the MCID value should be different depending on the intervention. Moreover, despite the efficacy of adopting percentage-change improvement for the MCID threshold, there are limited reports and discussions in the field of lumbar surgery.

PURPOSE

The aim of the present study was to elucidate the MCIDs for the Oswestry Disability Index (ODI), EuroQOL 5-dimension 3-level (EQ-5D-3L), physical component summary (PCS) of the Short Form of the Medical Outcomes Study, and Numeric Rating Scale (NRS) in patients with degenerative LSS treated with decompression surgery without fusion.

STUDY DESIGN/SETTING

A multicenter retrospective cohort study was performed.

PATIENT SAMPLE

A total of 422 patients who underwent decompression surgery for LSS and answered a complete set of questionnaires were included in the study. Patients who underwent endoscopic or revision surgery were excluded.

OUTCOME MEASURES

Preoperative and 1-year postoperative scores of each health-related quality of life questionnaires (HRQOLs) and patient satisfaction questionnaire response METHODS: The patient satisfaction question was used as an anchor, and the cutoff values were estimated based on absolute point improvement from baseline using a receiver-operating characteristic (ROC) curve analysis and the "mean change" method for MCIDs. The MCID values for percentage-change in HRQOLs were also calculated using ROC curve analysis. The three cutoff values for each HRQOL were validated using the Youden index for determining the most robust MCIDs.

RESULTS

Of the patients, 356 (84.4%) were at least "somewhat satisfied" with the treatment results. The two cutoff values of absolute point-change in each HRQOL, which were estimated by two different anchor-based methods, were similar. The area under the curve of the ROC curve for percentage-change tended to be higher than that for absolute point-change. Moreover, the Youden index of the percentage-change in each HRQOL was higher than that of the absolute point-change calculated by either the "mean change" method or the ROC curve analysis. Based on these results, it was proposed that MCID was 42.4% for percentage-change in ODI, 22.0% for EQ-5D-3L, 13.7% for PCS, 25.0% for NRS (low back pain), 55.6% for NRS (leg pain), 22.2% for NRS (leg numbness).

CONCLUSIONS

The MCIDs of HRQOLs were calculated in patients with LSS treated with decompression surgery without concomitant fusion procedure. The MCID cutoffs based on percentage-change from baseline were more effective than those of absolute point-change.

No Benefit with Preservation of Midline Structures in Decompression for Lumbar Spinal Stenosis: Results From the National Swedish Spine Registry 2-Year Post-Op

STUDY DESIGN

Observational cohort study.

OBJECTIVE

The aim of this study was to investigate whether preservation of the midline structures is associated with a better clinical outcome compared to classic central decompression for lumbar spinal stenosis (LSS).

SUMMARY OF BACKGROUND DATA

The classic surgical procedure for LSS is a central, facet joint sparing decompressive laminectomy (LE). Alternative approaches have been developed to preserve the midline structures. The effect of the alternative techniques compared to LE remains unclear.

METHODS

All patients >50 years of age who underwent decompression surgery for LSS without concomitant fusion in the National Swedish Spine Registry (Swespine) from December 31, 2015 until October 6, 2017 were included in this study based on surgeon-reported data and patient questionnaires before and 2 years postoperatively. Propensity score matching was used to compare decompression with preservation of midline structures with patients who underwent LE. The primary outcome was the Oswestry Disability Index (ODI) and secondary outcomes were the Numeric Rating Scale (NRS) for leg and back pain, EuroQol-5 Dimensions (EQ-5D), Global Assessment (GA), patient satisfaction and rate of subsequent surgery.

RESULTS

Some 3339 patients completed a 2-year follow-up. Of these, 2974 (89%) had decompression with LE and 365 underwent midline preserving surgery. Baseline scores were comparable between the groups. Mean ODI improvement at follow-up was 16.6 (SD = 20.0) in the LE group and 16.9 (SD = 20.2) in the midline preserving surgery group. In the propensity score-matched analysis the difference in improved ODI was 0.53 (95% confidence interval, CI -1.71 to 2.76; P = 0.64). The proportion of patients who showed a decreased ODI score of at least our defined minimal clinically important difference (=8) was 68.3% after LE and 67.0% after preserving the midline structures (P = 0.73). No significant differences were found in the improvement of NRS for leg and back pain, EQ-5D, GA or patient satisfaction. The rate of subsequent surgery was 5.5% after LE and 4.9% after midline preserving surgery without a significant difference in the propensity score-matched analysis (hazard ratio, HR 0.87; 95% CI 0.49-1.54; P = 0.64).

CONCLUSION

In this study on decompression techniques for LSS, there was no benefit in preserving the midline structures compared to LE 2 years after decompression. The conclusion is that the surgeon is free to choose the surgical method that is thought most suitable for the patient and the condition with which the patient presents.Level of Evidence: 3.

Preoperative Duration of Symptoms Does Not Affect Outcomes of Anterior Lumbar Interbody Fusion

BACKGROUND

Previous studies have examined the impact of preoperative duration of symptoms (DOS) on lumbar spinal surgery outcomes although this has not been explored for anterior lumbar interbody fusion (ALIF).

OBJECTIVE

To assess the impact of preoperative DOS on patient-reported outcome measures (PROMs) of ALIF with posterior instrumentation.

METHODS

A database was retrospectively reviewed for ALIFs with posterior instrumentation. PROMs recorded at preoperative, 6-wk, 12-wk, 6-mo, and 1-yr postoperative timepoints included Visual Analog Scale back and leg, Oswestry Disability Index, 12-Item Short-Form Physical Component Score (SF-12 PCS), and PROM Information System physical function. Achievement of minimum clinically important difference (MCID) was determined by comparing differences in postoperative PROMs from baseline to established values. Patients were grouped based on preoperative DOS into <1-yr and ≥1-yr groups. Differences in PROMs were compared using a t-test, whereas MCID achievement used a χ2 test.

RESULTS

Fifty-three patients were included, with 20 in the <1-yr group and 33 in the ≥1-yr group. The most common diagnosis was isthmic spondylolisthesis. No significant preoperative differences were observed in any PROM. DOS groups demonstrated significantly different scores for SF-12 PCS at 6 wk (P = .049). No significant differences in MCID achievement were observed between groups for any PROM.

CONCLUSION

ALIF patients demonstrated similar levels of pain, disability, and physical function regardless of preoperative DOS, except for back pain and physical function at intermittent timepoints. MCID achievement did not differ based on DOS for all outcome measures.

Minimum Clinically Important Difference: A Metric That Matters in the Age of Patient-Reported Outcomes

➤

As the Patient-Reported Outcomes Measurement Information System (PROMIS) is increasingly utilized in orthopaedic research and clinical practice, there is not a consensus regarding the minimum clinically important difference (MCID) calculation.

➤

The varied MCID calculation methods can lead to a range of possible values, which limits the translatability of research efforts.

➤

The completion rate and follow-up period also influence MCID values and should be reported alongside study results.

The Impact of Surgical Site Infection on Patient Outcomes After Open Posterior Instrumented Thoracolumbar Surgery for Degenerative Disorders

BACKGROUND

Few reports in the literature have described the long-term outcome of postoperative infection from the patient perspective. The aim of the present study was to determine if complicated surgical site infection (SSI) affects functional recovery and surgical outcomes up to 2 years after posterior instrumented thoracolumbar surgery for the treatment of degenerative disorders.

METHODS

This retrospective cohort study involved patients who had been enrolled in a previous randomized controlled trial that examined antibiotic use for open posterior multilevel thoracolumbar or lumbar instrumented fusion procedures. In the present study, patients who had SSI (n = 79) were compared with those who did not (n = 456). Patient-reported outcome measures (PROMs) included the Oswestry Disability Index (ODI), leg and back pain scores on a numeric rating scale, Short Form-12 (SF-12) summary scores, and satisfaction with treatment at 1.5, 3, 6, 12, and 24 months. Surgical outcomes included adverse events, readmissions, and additional surgery.

RESULTS

The median time to infection was 15 days. Of the 535 patients, 31 (5.8%) had complicated infections and 48 (9.0%) had superficial infections. Patients with an infection had a higher body mass index (BMI) (p = 0.001), had more commonly received preoperative vancomycin (p = 0.050), were more likely to have had a revision as the index procedure (p = 0.004), had worse preoperative mental functioning (mental component summary score, 40.7 ± 1.6 versus 44.1 ± 0.6), had more operatively treated levels (p = 0.024), and had a higher rate of additional surgery (p = 0.001). At 6 months after surgery, patients who developed an infection scored worse on the ODI by 5.3 points (95% confidence interval [CI], 0.4 to 10.1 points) and had worse physical functioning by -4.0 points (95% CI, -6.8 to -1.2 points). Comparison between the groups at 1 and 2 years showed no difference in functional outcomes, satisfaction with treatment, or the likelihood of achieving the minimum clinically important difference (MCID) for the ODI.

CONCLUSIONS

SSI more than doubled the post-discharge emergency room visit and additional surgery rates. Patients with SSI initially (6 months) had poorer overall physical function representing the delay to recovery; however, the negative impact resolved by the first postoperative year.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Stratifying outcome based on the Oswestry Disability Index for operative treatment of adult spinal deformity on patients 60 years of age or older: a multicenter, multi-continental study on Prospective Evaluation of Elderly Deformity Surgery (PEEDS)

BACKGROUND CONTEXT

Patients with adult spinal deformity suffer from disease related disability as measured by the Oswestry Disability Index (ODI) for which surgery can result in significant improvements.

PURPOSE

The purpose of this study was to show the change in overall and individual components of the ODI in patients aged 60 years or older following multi-level spinal deformity surgery.

STUDY DESIGN

Prospective, multicenter, multi-continental, observational longitudinal cohort study PATIENT SAMPLE: Patients ≥60 years undergoing primary spinal fusion surgery of ≥5 levels for coronal, sagittal or combined deformity.

OUTCOME MEASURES

Oswestry Disability Index (ODI) METHODS: : Patients completed the ODI pre-operatively for baseline, then at 10 weeks, 12 months and 24 months post-operatively. ODI scores were grouped into deciles, and change was calculated with numerical score and improvement or worsening was further categorized from baseline as substantial (≥20%), marginal (≥10-<20%) or no change (within 10%).

RESULTS

Two-hundred nineteen patients met inclusion criteria for the study. The median number of spinal levels fused was 9 [Q1=5.0, Q3=12.0]. Two-year mean (95% CI) ODI improvement was 19.3% (16.7%; 21.9%; p<.001) for all age groups, with mean scores improved from a baseline of 46.3% (44.1%; 48.4%) to 41.1% (38.5%; 43.6%) at 10 weeks (p<.001), 28.1% (25.6%; 30.6%) at 12 months (p<.001), and 27.0% (24.4%; 29.5%) at 24 months (p<.001). At 2 years, 45.5% of patients showed 20% or greater improvement in ODI, 23.7% improved between 10% and 20%, 26.3% reported no change (defined as±10% from baseline), 4.5% of patients reported a worsening between 10% to 20%, and none reported worsening greater than 20%. 59.0% of patients were severely disabled (ODI >40%) pre-operatively, which decreased to 20.2% at 2 years. Significant improvement was observed across all 10 ODI items at 12 and 24 months. The largest improvements were seen in pain, walking, standing, sex life, social life and traveling.

CONCLUSIONS

In this prospective, multicenter, multi-continental study of patients 60 years or older undergoing multi-level spinal deformity surgery, almost 70% of patients reported significant improvements in ODI without taking into account surgical indications, techniques or complications. Clear data is presented demonstrating the particular change from baseline for each decile of pre-operative ODI score, for each sub-score, and for each age group.

Assessment of the Minimum Clinically Important Difference in the Smartphone-based 6-minute Walking Test After Surgery for Lumbar Degenerative Disc Disease

STUDY DESIGN

Prospective cohort study.

OBJECTIVE

The aim of this study was to determine the minimum clinically important difference (MCID) of the 6-minute walking test (6WT) after surgery for lumbar degenerative disc disease (DDD).

SUMMARY OF BACKGROUND DATA

The smartphone-based 6WT is a valid and reliable tool to quantify objective functional impairment in patients with lumbar DDD. To date, the MCID of the 6WT has not been described in patients with DDD.

METHODS

We assessed patients pre- and 6-weeks postoperatively, analyzing both raw 6-minute walking distances (6WD; in meters) and standardized 6WT z scores. Three methods were applied to compute MCID values using established patient-reported outcomes measures (PROMs) as anchors (VAS back/leg pain, Zurich Claudication Questionnaire [ZCQ], Core Outcome Measures Index [COMI]): average change, minimum detectable change, and the change difference approach.

RESULT

We studied 49 patients (59% male) with a mean age of 55.5 ± 15.8 years. The computation methods revealed MCID values ranging from 81 m (z score of 0.9) based on the VAS back pain to 99 m (z score of 1.0) based on the ZCQ physical function scale. The average MCID of the 6WT was 92 m (z score of 1.0). Based on the average MCID of raw 6WD values or standardized z scores, 53% or 49% of patients classified as 6-week responders to surgery for lumbar DDD, respectively.

CONCLUSION

The MCID for the 6WT in lumbar DDD patients is variable, depending on the calculation technique. We propose a MCID of 92m (z score of 1.0), based on the average of all three methods. Using a z score as MCID allows for the standardization of clinically meaningful change and attenuates age- and sex-related differences.Level of Evidence: 3.

Factors associated with using an interbody fusion device for low-grade lumbar degenerative versus isthmic spondylolisthesis: a retrospective cohort study

OBJECTIVE

Many studies have utilized a combined cohort of patients with degenerative spondylolisthesis (DS) and isthmic spondylolisthesis (IS) to evaluate indications and outcomes. Intuitively, these are very different populations, and rates, indications, and outcomes may differ. The goal of this study was to compare specific patient characteristics associated with the utilization of a posterior lumbar interbody device between cohorts of patients with DS and IS, as well as to compare rates of interbody device use and patient-rated outcomes at 1 year after surgical treatment.

METHODS

The authors included patients who underwent posterior lumbar interbody fusion or instrumented posterolateral fusion for grade I or II DS or IS and had been enrolled in the Canadian Spine Outcomes and Research Network registry from 2009 to 2016. The outcome measures were score on the Oswestry Disability Index, scores for back pain and leg pain on the numeric rating scale, and mental component summary (MCS) score and physical component summary score on the 12-Item Short-Form Health Survey. Descriptive statistics were used to compare spondylolisthesis groups, logistic regression was used to compare interbody device use, and the chi-square test was used to compare the proportions of patients who achieved a minimal clinically important difference (MCID) at 1 year after surgery.

RESULTS

In total, 119 patients had IS and 339 had DS. Patients with DS were more commonly women, older, less likely to smoke, and more likely to have neurogenic claudication and comorbidities, whereas patients with IS more commonly had radicular pain, neurological deficits, and worse back pain. Spondylolisthesis was more common at the L4-5 level in patients with DS and at the L5-S1 level in patients with IS. Similar proportions of patients had an interbody device (78.6% of patients with DS vs 82.4% of patients with IS, p = 0.429). Among patients with IS, factors associated with interbody device utilization were BMI ≥ 30 kg/m2 and increased baseline leg pain intensity. Factors associated with interbody device utilization in patients with DS were younger age, increased number of total comorbidities, and lower baseline MCS score. For each outcome measure, similar proportions of patients in the surgical treatment and spondylolisthesis groups achieved the MCID at 1 year after surgery.

CONCLUSIONS

Although the demographic and patient characteristics associated with interbody device utilization differed between cohorts, similar proportions of patients attained clinically meaningful improvement at 1 year after surgery.

The effect of smoking on achieving meaningful clinical outcomes one year after lumbar tubular microdecompression: a matched-pair cohort analysis

BACKGROUND CONTEXT

There has been a shift in the spine literature in reporting meaningful outcomes, including meaningful clinically important difference (MCID), after surgery. The evidence on the effect of tobacco smoking at the time of lumbar tubular microdecompression (LTMD) on meaningful outcomes is limited.

PURPOSE

To compare differences in 1-year functional outcomes and rates of achieving MCID between current smokers and non-smokers who underwent LTMD for lumbar spinal stenosis (LSS).

STUDY DESIGN

A nested case control study to compare the difference in patient reported outcomes (PROs) between smokers and non-smokers 1-year after undergoing LTMD.

PATIENT SAMPLE

This study included patients that underwent single level LTMD by a single surgeon between January 2014 through August 2019.

OUTCOME MEASURES

Preoperative and postoperative PROs were recorded using the questionnaires EQ-5D, Oswestry Disability Index (ODI), and the visual analog scale (VAS) for back pain and leg pain. The MCID was also used.

METHODS

Current tobacco smokers at the time of surgery were matched 1:2 to non-smokers by age (+/- 1year). Preoperative and postoperative functional scores were compared between the two groups using independent t-tests. Additionally, thresholds for achieving MCID were calculated for each individual functional score, and were compared using Fisher's exact test.

RESULTS

Of the 183 patients with 1-year follow-up who met inclusion criteria, 35 patients were identified as smokers and were matched to 70 non-smokers. No statistical differences were identified between age, BMI, or gender. Comparison of preoperative PROs showed no statistically significant differences between smokers and non-smokers (p>0.05 for all), while smokers had statistically lower EQ-5D (p<0.001) and higher ODI (p=0.05), VAS back (p=0.033), and VAS leg (p=0.03) score averages at a minimum of one year follow-up. Evaluation of meaningful outcomes demonstrated non-smokers had higher rates of achieving MCID on at least 1 threshold score as compared to smokers (98.5% vs. 91.1%; p=0.043).

CONCLUSIONS

Current smokers at the time of surgery have inferior postoperative EQ-5D scores, increased pain and disability, and lower odds of achieving the MCID at 1-year after undergoing LTMD when compared to patients without any smoking history.

Defining minimal clinically important differences in pain and disability outcomes of patients with chronic pain treated with spinal cord stimulation

OBJECTIVE

Minimal clinically important difference (MCID) thresholds for a limited number of outcome metrics were previously defined for patients with failed back surgery syndrome (FBSS) at 6 months after spinal cord stimulation (SCS). This study aimed to further define MCID values for pain and disability outcomes. Additionally, the authors established 1-year MCID values for outcome measures with previously defined metrics commonly used to assess SCS efficacy.

METHODS

Preoperative and 1-year postoperative outcomes were collected from 114 patients who received SCS therapy for FBSS, complex regional pain syndrome, and neuropathic pain. MCID values were established for the numerical rating scale (NRS), Oswestry Disability Index (ODI), Beck Depression Inventory (BDI), McGill Pain Questionnaire (MPQ), and Pain Catastrophizing Scale (PCS). Four established anchor-based methods were utilized to compute MCID values with two anchored questions: "Are you satisfied with SCS therapy?" and "Would you have SCS surgery again?" For each question, patients were categorized as responders if they answered "yes" or as nonresponders if they responded "no." The methodologies utilized to compute MCID scores included the average change method, minimum detectable change approach, change difference calculation, and receiver operating characteristic (ROC) analysis. Area under the ROC curve (AUC) analysis has been shown to inform the accuracy at which the MCID value can distinguish responders from nonresponders and was analyzed for each instrument.

RESULTS

For the first time, ranges of MCID values after SCS were established for MPQ (1-2.3) and PCS (1.9-13.6). One-year MCID values were defined for all indications: NRS (range 0.9-2.7), ODI (3.5-6.9), and BDI (2-5.9). AUC values were significant for NRS (0.78, p < 0.001), ODI (0.71, p = 0.003), MPQ (0.74, p < 0.001), and PCS (0.77, p < 0.001), indicating notable accuracy for distinguishing satisfied patients.

CONCLUSIONS

This was the first study to successfully determine MCID values for two prominent instruments, MPQ and PCS, used to assess pain after SCS surgery. Additionally, previously established MCID values for ODI, BDI, and the visual analog scale for patients with FBSS at 6 months after treatment were explored at 12 months for the most common indications for SCS. These data may better inform physicians of patient response to and success with SCS therapy.

Charlson Comorbidity Index: An Inaccurate Predictor of Minimally Invasive Lumbar Spinal Fusion Outcomes

BACKGROUND

There is a scarcity of research on the Charlson Comorbidity Index (CCI) and its influence on minimum clinically important difference (MCID) achievement after minimally invasive (MIS) transforaminal lumbar interbody fusion (TLIF). The objective of this study is to detail the association between the CCI and attaining MCID after MIS TLIF.

METHODS

A prospective surgical registry was retrospectively reviewed for spine surgeries between May 2015 and February 2019. Inclusion criteria were primary or revision, 1- or 2-level MIS TLIF procedures. Patients were stratified based on CCI score: 0 points (no comorbidities), 1-2 points (mild CCI), ≥3 points (moderate CCI). Preoperative, intraoperative, and postoperative variables were assessed by subgroup using appropriate statistical analysis. Subgroups were analyzed with linear regression or χ² tests for continuous or categorical variables, respectively. Subgroup scores, improvement, and MCID achievement were assessed at postoperative timepoints (eg, 6 weeks, 12 weeks, 6 months, and 1 year) for back and leg pain, Oswestry Disability Index (ODI), SF-12 Physical Composite Score (PCS), and Patient-Reported Outcomes Measurement Information System Physical Function (PROMIS PF).

RESULTS

A total of 171 patients were included (n = 51 [no comorbidities], n = 73 [mild CCI], and n = 47 [moderate CCI]). Higher CCI patients were older and more likely to be smokers, diabetic, arthritic, hypertensive, or have a malignancy history (P < 0.003). Preoperatively, ODI and PROMIS PF were the only patient-reported outcomes with a significant association by CCI group (P = 0.015 and 0.014). Back pain was the only measure that had a significant association with the CCI subgroup at 1 year for score (P = 0.002) or MCID (P = 0.028).

CONCLUSIONS

By 1 year, regardless of the number of comorbidities, a similar proportion of patients undergoing MIS TLIF were able to achieve MCID for visual analog scale leg, SF-12 PCS, and PROMIS PF. Patients with higher comorbidities are not likely to experience a significant difference in symptom improvement. Regardless of CCI score, MIS TLIF can have a significant benefit for patients.

LEVEL OF EVIDENCE

4.

CLINICAL RELEVANCE

Text.

Tobacco use in the Myeloproliferative neoplasms: symptom burden, patient opinions, and care

BACKGROUND

Patients with Philadelphia-negative Myeloproliferative Neoplasms (MPN) suffer from numerous symptoms and decreased quality of life. Smoking is associated with an increased symptom burden in several malignancies. The aim of this study was to analyze the association between smoking and MPN-related symptom burden and explore MPN patients' opinions on smoking.

METHODS

A total of 435 patients with MPN participated in a cross-sectional internet-based survey developed by the Mayo Clinic and the Myeloproliferative Neoplasm Quality of Life Group. Patients reported their demographics, disease characteristics, tobacco use, and opinions on tobacco use. In addition, MPN-related symptoms were reported via the validated 10-item version of the Myeloproliferative Neoplasms Symptom Assessment Form.

RESULTS

Current/former smokers reported worse fatigue (mean severity 5.6 vs. 5.0, p = 0.02) and inactivity (mean severity 4.0 vs. 3.4, p = 0.03) than never smokers. Moreover, current/former smokers more frequently experienced early satiety (68.5% vs. 58.3%, p = 0.03), inactivity (79.9% vs. 71.1%, p = 0.04), and concentration difficulties (82.1% vs. 73.1%, p = 0.04). Although not significant, a higher total symptom burden was observed for current/former smokers (mean 30.4 vs. 27.0, p = 0.07). Accordingly, overall quality of life was significantly better among never smokers than current/former smokers (mean 3.5 vs. 3.9, p = 0.03). Only 43.2% of the current/former smokers reported having discussed tobacco use with their physician, and 17.5% did not believe smoking increased the risk of thrombosis.

CONCLUSION

The current study suggests that smoking may be associated with increased prevalence and severity of MPN symptoms and underscores the need to enhance patient education and address tobacco use in the care of MPN patients.

Clinically Meaningful Improvement Following Cervical Spine Surgery: 30% Reduction Versus Absolute Point-change MCID Values

STUDY DESIGN

Retrospective analysis of prospectively collected registry data.

OBJECTIVE

The aim of this study was to compare the performance of 30% reduction to established absolute point-change values for measures of disability and pain in patients undergoing elective cervical spine surgery.

SUMMARY OF BACKGROUND DATA

Recent studies recommend using a proportional change from baseline instead of an absolute point-change value to define minimum clinically important difference (MCID).

METHODS

Analyses included 13,179 patients who underwent cervical spine surgery for degenerative disease between April 2013 and February 2018. Participants completed a baseline and 12-month follow-up assessment that included questionnaires to assess disability (Neck Disability Index [NDI]), neck and arm pain (Numeric Rating Scale [NRS-NP/AP], and satisfaction [NASS scale]). Participants were classified as met or not met 30% reduction from baseline in each of the respective measures. The 30% reduction in scores at 12 months was compared to a wide range of established absolute point-change MCID values using receiver-operating characteristic curves, area under the receiver-operating characteristic curve (AUROC), and logistic regression analyses. These analyses were conducted for the entire patient cohort, as well as for subgroups based on baseline severity and surgical approach.

RESULTS

Thirty percent reduction in NDI and NRS-NP/AP scores predicted satisfaction with more accuracy than absolute point-change values for the total population and ACDF and posterior fusion procedures (P < 0.05). The largest AUROC differences, in favor of 30% reduction, were found for the lowest disability (ODI 0-20%: 16.8%) and bed-bound disability (ODI 81%-100%: 16.6%) categories. For pain, there was a 1.9% to 11% and 1.6% to 9.6% AUROC difference for no/mild neck and arm pain (NRS 0-4), respectively, in favor of a 30% reduction threshold.

CONCLUSION

A 30% reduction from baseline is a valid method for determining MCID in disability and pain for patients undergoing cervical spine surgery.Level of Evidence: 3.