Elderly as a Predictor for Perioperative Complications in Patients Undergoing Multilevel Minimally Invasive Transforaminal Lumbar Interbody Fusion: A Regression Modeling Study

Effects of BMI on SI joint fusion outcomes: examining the evidence to improve insurance guidelines

BACKGROUND CONTEXT

Obesity is increasing. Previous studies have demonstrated an association between obesity and adverse events after lumbar fusion. There is limited evidence on the effect of obesity on minimally invasive SI joint fusion (SIJF) outcomes.

PURPOSE

The purpose of this study was to investigate the impact of obesity on patient-reported outcomes in patients undergoing SIJF surgery using triangular titanium implants (TTI).

STUDY DESIGN

Retrospective cohort study based on four prospective clinical trials (INSITE [NCT01681004], SIFI [NCT01640353], iMIA [NCT01741025], and SALLY [NCT03122899]).

PATIENT SAMPLE

Adult patients ≥18 years of age who underwent minimally invasive surgery (MIS) sacroiliac joint (SIJ) fusion between 2012 and 2021.

OUTCOME MEASURES

Visual analog scale (VAS Pain), Oswestry Disability Index (ODI).

METHODS

Participants were classified using the National Institutes of Health body mass index (BMI). Patients with a BMI of 30 to 39 with no significant comorbidity are considered obese, patients with a BMI of 35 to 39 with a significant comorbidity or a BMI of 40 or greater are considered morbidly obese. All subjects underwent either minimally invasive SIJ fusion with TTI or nonsurgical management (INSITE and iMIA studies only). All subjects completed SIJ pain scale scores (measured with a 100-point VAS) and disability scores (measured with ODI) at baseline and at scheduled visits to 24 months. Repeated measures analysis of variance was used to examine the impact of BMI category on score changes.

RESULTS

In the SIJF group, mean SIJ pain improved at 24 months by 53.3 points (p<.0001). Over the 24-month follow-up period, BMI category did not impact mean improvement in SIJ pain scale score (repeated measures analysis of variance (ANOVA) p=.44). In the SIJF group, mean ODI at 24 months improved by 25.8 points (p<.0001). BMI category did not impact mean improvement in ODI (ANOVA p=.60). In the nonsurgical management (NSM) group, mean improvements in SIJ pain scale and ODI were clinically small (8.7 and 5.2 points, respectively) and not affected by BMI category (ANOVA p=.49 and .40).

CONCLUSION

This study demonstrates similar benefits and risks of minimally invasive SIJ fusion with TTI across all BMI categories. This analysis suggests that obese patients benefit from minimally invasive SIJ fusion and should not be denied this procedure based solely on elevated BMI.

The 5-Factor Modified Frailty Index is Associated With Increased Risk of Reoperations and Adjacent Level Disease Following Single-Level Transforaminal Lumbar Interbody Fusion

STUDY DESIGN

Retrospective Cohort Study.

OBJECTIVES

To determine the predictive capability between the 5-factor modified frailty index (mFI-5) scores and adverse clinical and radiographic outcomes following single-level transforaminal lumbar interbody fusion (TLIF).

METHODS

All patients over the age of 50 undergoing single-level open or minimally invasive TLIF from 2012 to 2021 with a minimum follow-up of 1 year were identified. Deformity, trauma, emergency, and tumor cases were excluded as were patients undergoing revision surgeries. An mFI-5 score was computed for each patient using a set of five factors which included hypertension requiring medication, chronic obstructive pulmonary disease, diabetes mellitus, congestive heart failure, and partially or fully dependent functional status. Univariate and multivariate logistic regression analysis were performed to evaluate the impact of mFI-5 scores on readmissions, reoperations, and postoperative complications.

RESULTS

156 patients were included and grouped according to their level of frailty: no-frailty (mFI = 0, n = 67), mild frailty (mFI = 1, n = 59), and severe frailty (mFI = 2+, n = 30). Multivariate analysis found high levels of frailty (mFI = 2+) to be independent predictors of reoperation (OR: 16.9, CI: 2.7 - 106.9, P = .003) and related readmissions (OR = 16.5, CI: 2.6 - 102.7, P = .003) as compared to the no-frailty group. An mFI-5 score of 2+ was also predictive of any complication (OR = 4.5, CI: 1.4 - 14.3, P = .01) and adjacent segment disease (ASD) (OR = 12.5, CI: 1.2 - 134.0, P = .037).

CONCLUSION

High levels of frailty were predictive of related readmissions, reoperations, any complications, and ASD in older adult patients undergoing single-level TLIF.

Is Advanced Age a Factor That Influences the Clinical Outcome of Single- or Double-Level MIS-TLIF? A Single-Center Study with a Minimum Two-Year Follow-Up on 103 Consecutive Cases

As life expectancy rises, more elderly people undergo spinal fusion surgery to treat lumbar degenerative diseases. The MIS-TLIF technique, which minimizes soft tissue manipulation, is a promising fusion technique for frailer patients. The aim of this study was to investigate if older age is a significant factor in the clinical outcome of single- or double-level MIS-TLIF. A cross-sectional study was conducted on 103 consecutive patients. Data were compared between younger (<65 y.o.) and older (≥65 y.o.) patients. We observed no significant differences between baseline characteristics of the two groups apart from the frequency of disk space treated, with a relative predominance of L3-L4 space treated in the elderly (10% vs. 28%, p = 0.01) and L5-S1 space in younger patients (36% vs. 5%, p = 0.006). There was no significant difference in complication rate, surgical satisfaction, EQ 5D-5L, or Oswestry Disability Index (ODI) global or specific scores, with the exception of the EQ 5D-5L "mobility" score, where older patients fared worse (1.8 ± 1.1 vs. 2.3 ± 1.4; p = 0.05). The minimal invasiveness of the surgical technique, age-related specific outcome expectations, and biomechanical issues are all potential factors influencing the lack of age group differences in outcome scores.

Comparison of hidden blood loss and clinical efficacy of percutaneous endoscopic transforaminal lumbar interbody fusion and minimally invasive transforaminal lumbar interbody fusion

Purpose

Hidden blood loss (HBL) is a growing area of interest for spinal surgeons. Simultaneously, spine surgeons’ pursuit of minimally invasive spine surgery has never ceased, as evidenced by the increasing number of articles comparing percutaneous endoscopic transforaminal lumbar interbody fusion (Endo-TLIF) and minimally invasive transforaminal lumbar interbody fusion (Mis-TLIF). However, there has been no comparison of HBL between Endo-TLIF and Mis-TLIF. This study aimed to compare HBL, visible blood loss (VBL), and total blood loss (TBL) following Endo-TLIF and Mis-TLIF and evaluate the clinical significance of these procedures.

Methods

Between October 2017 and October 2019, 370 patients underwent lumbar interbody fusion at our institution and were followed up for at least 24 months. Our study included 41 Endo-TLIF and 43 Mis-TLIF cases. We recorded each patient’s age, height, weight, and haematocrit and calculated the TBL, which was used to indirectly obtain the HBL. Additionally, we compared the clinical outcomes of these two groups, including visual analogue scores for the lumbar spine and leg (VAS-Back; VAS-Leg), Oswestry Disability Index (ODI), Japanese Orthopaedic Association (JOA) scores, disease type, operative segment, and intervertebral fusion and complication rates.

Results

Endo-TLIF had significantly lower HBL, VBL, and TBL values than Mis-TLIF (P < 0.05 for all). Although Endo-TLIF contained significantly less HBL than Mis-TLIF, the HBL to TBL ratio was statistically greater in Endo-TLIF (91%) than in Mis-TLIF (87%). Concerning clinical outcomes, VAS-Back, VAS-Leg, ODI, JOA, and Endo-TLIF demonstrated greater improvement rates than Mis-TLIF one week post-operatively. However, at the final follow-up, VAS-Back, VAS-Leg, ODI, and JOA scores all demonstrated a trend toward sustained improvement, with no statistically significant between-procedure difference. There were no statistically significant between-procedure differences in disease type, surgical segment, and complication or fusion rates.

Conclusion

Endo-TLIF significantly reduced HBL, VBL, and TBL compared to Mis-TLIF and improved short-term clinical outcomes; however, long-term clinical outcomes and fusion rates remained comparable between the two groups, as did the incidence of peri-operative complications.

Outcomes and complications of minimally invasive transforaminal lumbar interbody fusion in the elderly: a systematic review and meta-analysis

OBJECTIVE

Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) may be used to treat degenerative spinal pathologies while reducing risks associated with open procedures. As an increasing number of lumbar fusions are performed in the aging United States population, MIS-TLIF has been widely adopted into clinical practice in recent years. However, its complication rate and functional outcomes in elderly patients remain poorly characterized. The objective of this study was to assess complication rates and functional outcomes in elderly patients (≥ 65 years old) undergoing MIS-TLIF.

METHODS

The PubMed, Embase, and Scopus databases were searched for relevant records in accordance with the PRISMA guidelines. Inclusion criteria were peer-reviewed original research; English language; full text available; use of MIS-TLIF; and an elderly cohort of at least 5 patients. Risk of bias was assessed using the ROBINS-I (Risk of Bias in Nonrandomized Studies-of Interventions) tool. Pooled complication rates were calculated for elderly patients, with subgroup analyses performed for single versus multiple-level fusions. Complication rates in elderly compared to nonelderly patients were also assessed. Postoperative changes in patient-reported outcomes, including Oswestry Disability Index (ODI) and visual analog scale (VAS) back pain (BP) and leg pain (LP) scores, were calculated.

RESULTS

Twelve studies were included in the final analysis. Compared to nonelderly patients, MIS-TLIF in elderly patients resulted in significantly higher rates of major (OR 2.15, 95% CI 1.07-4.34) and minor (OR 2.20, 95% CI 1.22-3.95) complications. The pooled major complication rate in elderly patients was 0.05 (95% CI 0.03-0.08) and the pooled minor complication rate was 0.20 (95% CI 0.13-0.30). Single-level MIS-TLIF had lower major and minor complication rates than multilevel MIS-TLIF, although not reaching significance. At a minimum follow-up of 6 months, the postoperative change in ODI (-30.70, 95% CI -41.84 to -19.55), VAS-BP (-3.87, 95% CI -4.97 to -2.77), and VAS-LP (-5.11, 95% CI -6.69 to -3.53) in elderly patients all exceeded the respective minimum clinically important difference. The pooled rate of fusion was 0.86 (95% CI 0.80-0.90).

CONCLUSIONS

MIS-TLIF in elderly patients results in a high rate of fusion and significant improvement of patient-reported outcomes, but has significantly higher complication rates than in nonelderly patients. Limitations of this study include heterogeneity in the definition of elderly and limited reporting of risk factors among included studies. Further study of the impact of complications and the factors predisposing elderly patients to poor outcomes is needed.

Comparison of Lumbar Fusion With and Without Interbody Fusion for Lumbar Stenosis Using Patient-Reported Outcomes Measurement Information System (PROMIS) Computer Adaptive Testing (CAT)

Study design

This was a retrospective analysis of patient-reported outcomes across a two-year period.

Summary of background data

Patients suffering from lumbar stenosis may experience low back pain, neurogenic claudication, and weakness. Patients can benefit from surgical intervention, including decompression with or without fusion. However, the superiority of any single fusion construct remains controversial.

Objective

The goal of this study was to compare Patient-Reported Outcomes Measurement Information System (PROMIS®) Computer Adaptive Testing (CAT) measures in patients with lumbar spinal stenosis treated surgically with lumbar decompression and fusion with or without interbody fusion.

Methods

A retrospective review of patients with lumbar stenosis undergoing lumbar decompression and one-level fusion was performed. PROMIS® CAT Physical Function (PF) and Pain Interference (PI) assessments were administered using a web-based platform pre and postoperatively.

Results

Sixty patients with lumbar stenosis undergoing one-level lumbar fusion were identified. Twenty-seven patients underwent posterior lumbar fusion (PSF) alone and 33 underwent one-level lumbar interbody fusion (IF). Patients undergoing IF had better absolute PF scores compared to patients undergoing PSF at one-year postoperatively (48.9 v 41.6, p=0.002) and greater relative improvement in PF scores from baseline at one-year postoperatively (D13.6 v D8.6, p=0.02). A subgroup analysis of patients undergoing TLIF v PSF showed better absolute PF scores at the one-year follow-up in the TLIF group (47.1 v 42.3, p=0.04). No differences were found in PI scores at any time point between the PSF and IF groups. Patients undergoing IF had significantly shorter hospital stays (2.5 v 3.3 days, p=0.02) compared to patients undergoing PSF.

Conclusions

Patients with lumbar spinal stenosis treated with one-level IF reported higher absolute PF scores and experienced greater relative improvement in PF scores from baseline at one-year follow-up compared to patients treated with PSF alone. Additionally, IF is associated with a decreased length of hospital stay as compared to PSF.

Smoking Is Associated With Lower Satisfaction in Nondiabetic Patients Undergoing Minimally Invasive Single-level Transforaminal Lumbar Interbody Fusion

STUDY DESIGN

This was a retrospective review of prospectively collected registry data.

OBJECTIVE

The objective of this study was to investigate the effect of smoking on 2 years postoperative functional outcomes, satisfaction, and radiologic fusion in nondiabetic patients undergoing minimally invasive transforaminal lumbar interbody fusion (TLIF) for degenerative spine conditions.

SUMMARY OF BACKGROUND DATA

There is conflicting data on the effect of smoking on long-term functional outcomes following lumbar fusion. Moreover, there remains a paucity of literature on the influence of smoking within the field of minimally invasive spine surgery.

METHODS

Prospectively collected registry data of nondiabetic patients who underwent primary single-level minimally invasive TLIF in a single institution was reviewed. Patients were stratified based on smoking history. All patients were assessed preoperatively and postoperatively using the Numerical Pain Rating Scale for back pain and leg pain, Oswestry Disability Index, Short-Form 36 Physical and Mental Component Scores. Satisfaction was assessed using the North American Spine Society questionnaire. Radiographic fusion rates were compared.

RESULTS

In total, 187 patients were included, of which 162 were nonsmokers, and 25 had a positive smoking history. In our multivariate analysis, smoking history was insignificant in predicting for minimal clinically important difference attainment rates in Physical Component Score and fusion grading outcomes. However, in terms of satisfaction score, positive smoking history remained a significant predictor (odds ratio=4.7, 95% confidence interval: 1.10-20.09, P=0.036).

CONCLUSIONS

Nondiabetic patients with a positive smoking history had lower satisfaction scores but comparable functional outcomes and radiologic fusion 2 years after single-level TLIF. Thorough preoperative counseling and smoking cessation advice may help to improve patient satisfaction following minimally invasive spine surgery.

LEVEL OF EVIDENCE

Level III-nonrandomized cohort study.

Myocardial Infarction After Lumbar Surgery: A Critical Meta-Analysis of Cohort versus Database Studies for a Rare Complication

BACKGROUND

One potentially fatal complication of spine surgery is myocardial infarction (MI). There is still uncertainty of the true incidence of MI within subsets of spine surgeries. The aim of this study was to survey the contemporary spine literature and ascertain the true incidence of MI after lumbar spine surgery, as well as to provide commentary on the inherent assumptions made when interpreting cohort versus database studies on this topic.

METHODS

A systematic search of 4 electronic databases from inception to November 2020 was conducted following PRISMA guidelines. Articles were screened against prespecified criteria. MI incidence was then estimated by random-effects meta-analyses of proportions based on cohort versus database studies.

RESULTS

A total of 34 cohort studies and 32 database studies describing 767,326 lumbar procedures satisfied all criteria for selection. There were 12,170 (2%) cases from cohort studies and 755,156 (98%) cases from database studies. Cohort studies reported a significantly older patient cohort (P < 0.01) and longer follow-up period than did database studies (P < 0.03). Using cohort studies only, the incidence of MI was 0.44% (P heterogeneity < 0.01), whereas using database studies only, the incidence of MI was 0.41% (P heterogeneity < 0.01). These 2 incidences were statistically different (P interaction = 0.01). Bias analysis indicated that cohort studies were more vulnerable to small-study biases than were database studies.

CONCLUSIONS

Although infrequent, the incidence of MI after lumbar spine surgery is unequivocally nonzero. Furthermore, the literature on this topic remains skewed based on study type, and translation of academic findings into practice should be wary of this.

Impact of Advanced Age on Postoperative Outcomes Following Transforaminal Lumbar Interbody Fusion

INTRODUCTION

Age 65 years or older is considered a risk factor for worse outcomes after transforaminal lumbar interbody fusion (TLIF). However, few studies have differentiated this cohort from younger patients. This study compares postoperative outcomes among patients 65 years or older of age with a younger cohort after minimally invasive (MIS) TLIF.

METHODS

A database was reviewed for adults undergoing primary, elective, single-level MIS TLIF procedures for degenerative pathology from 2008 to 2019. Outcomes included visual analogue scale (VAS) for back and leg, Oswestry Disability Index (ODI), Short Form 12-Item physical component score (SF-12 PCS), and Patient-Reported Outcome Measurement Information System physical function. Outcomes were collected preoperatively and at 6 weeks, 12 weeks, 6 months, and 1 year postoperatively. Patients were categorized as ≥75 years, 65 to 74 years, or <65 years of age. Propensity score matching was performed, and outcome improvement and minimum clinically important difference (MCID) achievement were evaluated by group. MCID achievement was calculated using previously established values.

RESULTS

Our cohort included 51 patients aged younger than 65 years, 47 patients aged 65 to 74 years, and 16 patients aged 75 years or older. No significant perioperative differences or complications existed between groups. The 65- to 74-year group improved in VAS back, leg, and ODI from 6 weeks to 1 year (all P < 0.001) and SF-12 PCS at 12 weeks to 1 year (all P < 0.005). VAS back, ODI, and SF-12 PCS differed between groups preoperatively (P < 0.050), and VAS back and ODI varied at 6 weeks (P < 0.01). VAS leg differed between groups at 12 weeks and SF-12 PCS at 1 year (both P < 0.050). MCID achievement was similar between groups except for VAS leg at 6 weeks (P = 0.038) and 12 weeks (P = 0.023).

CONCLUSION

Patients 65 years or older of age markedly improved from baseline, similarly to younger patients. Postoperative outcome scores and MCID achievement demonstrated differences between groups at intermittent timepoints. With appropriate selection criteria, patient age may not act as a notable risk factor for successful MIS TLIF procedures.

Surgical site infection after posterior lumbar interbody fusion and instrumentation in patients with lumbar degenerative disease

We designed this retrospective study with aims to investigate the incidence and risk factors associated with surgical site infection (SSI) following posterior lumbar interbody fusion (PLIF) and instrumentation in patients with lumbar degenerative disease. Eligible patients treated between January 2016 and June 2019 were included. Electronic medical records were inquired for data extraction and collection. Patients with SSI and without SSI were compared using the univariate analyses, and the association between variables and risk of SSI was investigated using multivariate logistics regression analyses. Among 1269 patients, 43 were found to have SSI, indicating a rate of 3.4%. Microbiological culture tests showed 88.4% patients had a positive result. Four SSIs were caused by mixed bacterial, and the remaining 34 by single bacteria. Multiple drug‐resistant strains were detected in 25 (65.8%) SSIs, with meticillin‐resistant coagulase‐negative staphylococcus (MRCNS) predominating (12, 48.0%). ASA III and above (odd ratio (OR), 1.67; 95% confidence interval (CI), 1.11 to 3.07), preoperative stay (OR, 1.13; 95% CI, 1.04 to 1.23), heart disease (OR, 2.88; 95% CI, 1.24 to 6.71), diabetes mellitus (OR, 3.28; 95% CI, 1.66 to 6.47) and renal insufficiency (OR, 4.23; 95% CI, 1.26 to 10.21), prolonged prophylactic antibiotics use (OR, 4.43; 95% CI, 2.30 to 8.54), and the reduced lymphocyte count (OR, 2.11; 95% CI, 1.03 to 4.33) were identified as independent risk factors associated with SSI. These factors, although most not modifiable, should be kept in mind, optimised for surgical conditions, or readily adjusted in the future postoperative management of antibiotics, to reduce postoperative SSIs.

Minimally Invasive Versus Open Surgery for Degenerative Spine Disorders for Elderly Patients: Experiences from a Single Institution

BACKGROUND

Minimally invasive surgery (MIS) of the spine has been associated with lower complication rates and improved patient-reported outcomes in recent studies. In this study, we aimed to investigate operative and postoperative outcomes associated with both surgical techniques in elderly patients.

METHODS

Patients who are 65 years old or older underwent either minimally invasive or open surgery for lumbar degenerative conditions. Patients with a nondegenerative cause such as infection or trauma were excluded from the analysis. Patient characteristics such as demographics and associated comorbidities as well as perioperative and postoperative complications were collected. Outcomes of interest were operative time, estimated blood loss (EBL), length of stay (LOS), readmissions, reoperations, and any complications.

RESULTS

A total of 107 elderly patients were identified for this study, with a median age of 73.0 years. Demographics and comorbidities in both groups were similar in both groups. Univariate analysis yielded an MIS group with significantly lower EBL (P < 0.001), operative time (P < 0.001), and LOS (P < 0.001). In multivariable analysis, EBL and LOS were found to be significantly lower in the MIS group (P = 0.02 and 0.001, respectively). Rates of complications, readmissions (no readmissions in MIS group), reoperations, and pain improvement also favored the MIS group and although they were not found to be significantly different between the 2 groups on univariate and multivariable analysis, the results trended toward significance.

CONCLUSIONS

These findings suggest that minimally invasive spine surgery in the elderly is safe and may pose a lower risk of associated perioperative and postoperative complications with faster recovery time.