Influence of Osteoporosis Following Spine Surgery on Reoperation, Readmission, and Economic Costs: An 8-Year Nationwide Population-Based Study in Korea

Clinical and Economic Outcomes of Patients with Osteoporosis Undergoing Spine Fusion Surgery in Japan

Introduction

Spinal fusion surgery with instrumentation is a treatment of choice for many spinal disorders; however, there is little data related to factors associated with early and late outcomes, especially among patients with poor bone quality (e.g., osteoporosis). We conducted this study to characterize the epidemiology and outcomes of patients undergoing spinal fusion surgery with instrumentation in Japan, especially in patients with poor bone quality and those needing additional fixation methods.

Methods

This retrospective observational study used real-world health insurance claims data from the Japanese Medical Data Vision. Adult patients undergoing an index spinal fusion procedure from April 1, 2010, to September 30, 2017, with procedural details, length of stay (LOS), total in-hospital costs, spine-related reoperation, all-cause readmission, and postoperative complications recorded. Data were summarized descriptively overall, by osteoporosis status, and additional fixation method used, and were analyzed in bivariate analyses. Multivariate logistic and linear regressions were used to explore associations between covariates and variables of interest.

Results

A total of 22,932 patients (mean age, 67.3 years; 51.2% male) met the study criteria and were included. A total of 5,288 (23.0%) patients had osteoporosis, and 2,507 (10.9%) needed additional fixation methods; these patients were older, more frequently female, and had higher Elixhauser comorbidity index scores. Osteoporosis and additional fixation use were also associated with longer LOS, higher hospital costs, and higher rates of complications.

Conclusions

Patients with osteoporosis and those needing additional fixation methods have a higher risk for procedural and postoperative complications, reoperation, longer LOS, and higher total hospital costs.

Progression to fusion after lumbar laminectomy for degenerative lumbar spondylolisthesis: Rate and risk-factors. A national database study

OBJECTIVE

Lumbar laminectomy is often utilized in the treatment of degenerative lumbar spondylolisthesis. Risk factors that contribute to reoperation rates, in particular to progression to fusion, are poorly understood. We aimed to identify rate and risk factors of lumbar fusion surgery following lumbar laminectomy for the treatment of degenerative lumbar spinal spondylolisthesis.

METHODS

Our sample was obtained from the national MarketScan Commercial Claims and Encounters Database. We reviewed patients undergoing lumbar laminectomy for stable degenerative lumbar spondylolisthesis (Grade-1) at one or two levels between January 2007 and December 2016.

RESULTS

A total of 33,681 patients were included. By 2 years after the index operation, 2.48 % of patients had required lumbar fusion surgery. Female sex was associated with lower odds (OR 0.8, 95 %CI 0.7-0.9) of reoperation for fusion. Diabetes (OR 1.2, 95 %CI 1.1-1.4), rheumatoid arthritis (OR 1.5, 95 %CI 1.2-1.7) and clinical presentation with LBP (OR 2.1, 95 %CI 1.6-2.9), lower extremity weakness (OR 1.4, 95 %CI 1.1-1.5), as well as occurrence of a postoperative neurological complications (OR 2.0, 95 %CI 1.1-3.4) increased the odds ratio for requiring fusion surgery within two years after lumbar laminectomy.

CONCLUSION

In this large cross-sectional sample of a national claims database consisting of lumbar laminectomy patients for the treatment of spondylolisthesis, approximately 2.5 % required subsequent lumbar fusion. Several modifiable risk factors for fusion progression were identified, which may guide clinicians in shared decision-making and to help identify patients with elevated post-operative risk providing potential leverage point for prevention.

Abdominal aortic calcification assessed on standard lateral lumbar radiographs as a screening tool for impaired bone status in spine surgery

PURPOSE

The aim of this study was to determine whether the presence of abdominal aortic calcification (AAC) can predict patient bone status, represented by volumetric bone mineral density (vBMD) assessed with quantitative computed tomography (QCT).

METHODS

Patients undergoing lumbar fusion surgery at a tertiary care center between 2014 and 2021, with a preoperative lumbar CT-scan and lateral lumbar radiographs were retrospectively reviewed. A semi-quantitative measurement method for AAC (AAC 4, 8 and 24) was performed. QCT measurements were made for L1 and L2. Patients were divided into two groups depending on whether AAC was present. A one-way analysis of covariance was conducted to adjust for age. A multiple linear regression model was used to test if age, sex, BMI, diabetes, hypertension, smoking and presence of AAC could predict the vBMD. A receiver operating characteristic (ROC) analysis was conducted for predicting impaired bone status.

RESULTS

267 patients with a median age of 65.1 years and BMI of 29.8 kg/m2 were analyzed, 59.6% of patients had AAC. The group comparison showed that vBMD was significantly lower in patients with the presence of AAC (97.8 mg/cm3 vs. 121.5 mg/cm3). Age (β = - 0.360; p < 0.001) and presence of AAC (β = -0.206; p = 0.005) significantly predict vBMD as independent variables. Impaired bone status could be discriminated using AAC 4, 8 and 24 (cut off value 0.5) with a sensitivity of 70.1% and a specificity of 60.2%.

CONCLUSION

The presence of AAC may identify patients at risk for impaired bone status. Preoperative evaluation of standard lumbar radiographs could be used as a potential diagnostic tool in assessing bone status.

Perioperative Management of Comorbidities in Spine Surgery

The number of spinal operations performed in the United States has significantly increased in recent years. Along with these rising numbers, there has been a corresponding increase in the number of patient comorbidities. The focus of this article is to review comorbidities in Spine surgery patients and outline strategies to optimize patients and avoid complications.

Incidence and risk factors for early and late reoperation following lumbar fusion surgery

STUDY DESIGN

Retrospective cohort study.

PURPOSE

The aim of our study was to determine the rates and indications of reoperations following primary lumbar fusion, as well as the independent risk factors for early and late reoperation.

METHODS

We retrospectively reviewed patients who underwent lumbar fusion surgery between January 2017 and March 2020. All patients were followed up for more than 2 years. Characteristics, laboratory tests, primary diagnosis and surgery-related variables were compared among the early reoperation (< 3 months), the late reoperation (> 3 months) and the non-reoperation groups. Multivariable logistic regression analysis was used to identify independent risk factors for early and late reoperations.

RESULTS

Of 821 patients included in our studies, 34 patients underwent early reoperation, and 36 patients underwent late reoperation. The cumulative reoperation rate was about 4.1% (95% CI 3.8-4.5%) at 3 months, 6.2% (95% CI 5.9-6.5%) at 1 year and 8.2% (95% CI 8.0-8.5%) at 3 years. Multivariable analysis indicated that osteoporosis (odds ratio [OR] 3.6, 95% CI 1.2-10.5, p = 0.02) and diabetes (OR 2.1, 95% CI 1.1-4.5, p = 0.04) were independently associated with early reoperation and multilevel fusion (OR 2.4, 95% CI 1.1-5.4, p = 0.03) was independently associated with late reoperation.

CONCLUSIONS

The most common reasons for early reoperation and late operation were surgical site infection and adjacent segment diseases, respectively. Osteoporosis and diabetes were independent risk factors for early reoperation, and multilevel fusion was independent risk factor for late reoperation. Surgeons should pay more attention to these patients, and future studies should consider the effects of follow-up periods on results.

The Human Gut Microbiota: A Key Mediator of Osteoporosis and Osteogenesis

An expanding body of research asserts that the gut microbiota has a role in bone metabolism and the pathogenesis of osteoporosis. This review considers the human gut microbiota composition and its role in osteoclastogenesis and the bone healing process, specifically in the case of osteoporosis. Although the natural physiologic processes of bone healing and the pathogenesis of osteoporosis and bone disease are now relatively well known, recent literature suggests that a healthy microbiome is tied to bone homeostasis. Nevertheless, the mechanism underlying this connection is still somewhat enigmatic. Based on the literature, a relationship between the microbiome, osteoblasts, osteoclasts, and receptor activator of nuclear factor-kappa-Β ligand (RANKL) is contemplated and explored in this review. Studies have proposed various mechanisms of gut microbiome interaction with osteoclastogenesis and bone health, including micro-RNA, insulin-like growth factor 1, and immune system mediation. However, alterations to the gut microbiome secondary to pharmaceutical and surgical interventions cannot be discounted and are discussed in the context of clinical therapeutic consideration. The literature on probiotics and their mechanisms of action is examined in the context of bone healing. The known and hypothesized interactions of common osteoporosis drugs and the human gut microbiome are examined. Since dysbiosis in the gut microbiota can function as a biomarker of bone metabolic activity, it may also be a pharmacological and nutraceutical (i.e., pre- and probiotics) therapeutic target to promote bone homeostasis.