The effect of sarcopenia in the clinical outcomes following stand-alone lateral lumbar interbody fusion

Impact of sarcopenia on outcomes following lumbar spine surgery for degenerative disease: an updated systematic review and meta-analysis

PURPOSE

This study aimed to consolidate the evidence regarding the prognostic influence of sarcopenia in degenerative lumbar spine surgeries.

METHODS

A literature search of public databases was conducted up to Nov 15, 2023 using combinations of the key words "sarcopenia" and "lumbar spine surgery". Eligible studies were those that focused on adults undergoing decompression or fusion surgery for degenerative lumbar spine diseases, and compared the outcomes between patients with and without preoperative sarcopenia. Primary outcomes were change in ODI and back and leg pain VAS pain scores. Secondary outcomes were changes in Eq. 5D, JOA, SFHS-p scores, and LOS.

RESULTS

Ultimately, nine retrospective studies with a total of 993 patients were included. Sarcopenic patients exhibited significantly worse functional improvement as assessed by ODI compared to non-sarcopenic patients (pooled standardized mean difference [pSMD] = 0.53, 95% confidence interval [CI]: 0.17-0.90). Back pain (pSMD = 0.31, 95% CI:0.15-0.47) and leg pain (pSMD = 0.21, 95% CI:0.02 - 0.39) improvement were also less in sarcopenic patients. Non-sarcopenic patients had greater improvements in Eq. 5D (pSMD = 0.25) and SFHS-p (pSMD = 0.39), and shorter LOS (pSMD = 0.62).

CONCLUSIONS

As compared to patients without sarcopenia, those with sarcopenia undergoing lumbar spine surgery for degenerative diseases have lower improvements in functional ability, quality of life, physical health, pain relief and extended hospitalization compared to those without sarcopenia.

Correlation between MRI-based spinal muscle parameters and the vertebral bone quality score in lumbar fusion patients

Introduction

The vertebral bone quality (VBQ) score that is based on non-contrast enhanced T1-weighted MRI was recently introduced as a novel measure of bone quality in the lumbar spine and shown to be a significant predictor of healthy versus osteopenic/osteoporotic bone.

Research question

This study aimed to assess possible correlations between the VBQ score and the functional cross-sectional area (FCSA) of psoas and lumbar spine extensor muscles.

Material and methods

Patients who underwent fusion surgery between 2014 and 2017 and had lumbar MRI and CT scans within 6 months prior to surgery were included. The FCSA was assessed at L3-L5 using a pixel intensity threshold method. The VBQ score was calculated by dividing the signal intensity (SI) of the vertebrae L1-L4 through the SI of the cerebrospinal fluid at L3. Volumetric bone mineral density (vBMD) was assessed by quantitative CT.

Results

80 patients (58.8% female, median age 68.8 years) were included. Overall prevalence of osteopenia/osteoporosis was 66.3%, with no significant differences between men and women. The mean (SD) VBQ score was significantly smaller in men, at 2.26 (0.45) versus women at 2.59 (0.39) (p = 0.001). After adjusting for age and BMI, a significant negative correlation was seen between the VBQ score and psoas FCSA at L3 (β = -0.373; p = 0.022), but only in men.

Conclusion

Our results highlight sex differences in the VBQ score that were not demonstrated by vBMD and suggest a potential role of this novel measure to assess not only bone quality, but also spinal muscle quantity.

Impact of Sarcopenia on Spinal Spondylosis: A Literature Review

Sarcopenia and spinal spondylosis (SS) are important health challenges among older individuals; however, data regarding the effect of sarcopenia on SS are lacking. Hence, we aimed to organize the existing knowledge on the impact of sarcopenia on SS and explore potential issues in the available literature. We examined the trends and interventions regarding sarcopenia and SS, searching five databases (PubMed, Embase, CINHAL, Web of Science, and Cochrane Library) from inception to January 2023. Sarcopenia-related events were screened, selected, and reviewed, ultimately identifying 19 relevant studies. The identified reports were predominantly retrospective observational studies addressing lumbar degenerative spine disease (LDSD). Sarcopenia could negatively impact the quality of life and postoperative outcomes in several diseases, including cervical spondylotic myelopathy (CSM) and LDSD. However, there was no consensus among the studies regarding the relationship between sarcopenia and pain. These discrepancies were attributed to gaps in the assessment of sarcopenia, which the current study identifies as important challenges. This review identified several problems in the literature, including the limited number of studies examining CSM, adult spinal deformity (ASD) and scoliosis, and the retrospective study design of most reports. The further accumulation of quality research is needed to clarify the relationship between SS and sarcopenia.

Changes in psoas and posterior paraspinal muscle morphology after standalone lateral lumbar interbody fusion: a quantitative MRI-based analysis

PURPOSE

Standalone lateral lumbar interbody fusion (SA-LLIF) without posterior instrumentation can be an alternative to 360° fusion in selected cases. This study aimed to investigate quantitative changes in psoas and paraspinal muscle morphology that occur on index levels after SA-LLIF.

METHODS

Patients undergoing single- or multi-level SA-LLIF at L2/3 to L4/5 who had preoperative and postoperative lumbar MRI scans, the latter performed between 3 and 18 months after surgery for any reason, were retrospectively included. Muscle measurements were performed of the psoas and posterior paraspinal muscles (PPM; erector spinae and multifidus) on index levels using manual segmentation and an automated pixel intensity threshold method to differentiate muscle from fat signal. Changes in the total cross-sectional area (TCSA), the functional cross-sectional area (FCSA), and the percentage of fat infiltration (FI) of these muscles were assessed.

RESULTS

A total of 67 patients (55.2% female, age 64.3 ± 10.6 years, BMI 26.9 ± 5.0 kg/m2) with 125 operated levels were included. Follow-up MRI scans were performed after an average of 8.7 ± 4.6 months, primarily for low back pain. Psoas muscle parameters did not change significantly, irrespective of the approach side. Among PPM parameters, the mean TCSA at L4/5 (+ 4.8 ± 12.4%; p = 0.013), and mean FI at L3/4 (+ 3.1 ± 6.5%; p = 0.002) and L4/5 (+ 3.0 ± 7.0%; p = 0.002) significantly increased.

CONCLUSION

Our study demonstrated that SA-LLIF did not alter psoas muscle morphology, underlining its minimally invasive nature. However, FI of PPM significantly increased over time despite the lack of direct tissue damage to posterior structures, suggesting a pain-mediated response and/or the result of segmental immobilization.

Sarcopenia and Postoperative Complications, Cost of Care, and All-Cause Hospital Readmission Following Lumbar Spine Arthrodesis: A Propensity Matched Cohort Study

OBJECTIVE

Sarcopenia, characterized by decreased muscle mass and function, is projected to affect more than 200 million people worldwide by 2060. This study aimed to evaluate the rates of short-term complications following lumbar spine arthrodesis in patients with and without a recent diagnosis of sarcopenia.

METHODS

The PearlDiver database was queried to evaluate all patients who underwent index lumbar spine arthrodesis from 2012 to 2019. Multivariate logistic regression was used to compare rates of 90-day surgical and medical complications. Kaplan-Meier analysis was performed to compare cumulative rates of reoperation and all-cause hospital readmission. Two sample t testing was used to compare costs of care. Statistical significance was set at P < 0.05 a priori.

RESULTS

Of 239,953 patients undergoing lumbar spine arthrodesis, 1087 had a recent diagnosis of sarcopenia (0.45%) before surgery. Patients with sarcopenia were significantly more likely to experience a urinary tract infection (odds ratio = 1.41, P = 0.035) and undergo incision and drainage (odds ratio = 2.66, P = 0.010) within 90 days after lumbar arthrodesis. Patients with sarcopeniawere at a 24% greater risk of 1-year all-cause hospital readmission. The 90-day cost of care was significantly greater in patients with sarcopenia ($37,689.86 vs. $26,635.72; P < 0.001).

CONCLUSIONS

In patients undergoing lumbar spine arthrodesis, sarcopenia is associated with an increased risk of postoperative complications, including increased costs of care. Spine surgeons should consider screening patients for sarcopenia preoperatively and counsel them regarding their increased risk of complications. Additionally, surgeons may consider preoperative optimization, like the management of low bone density.

The predictive value of psoas and paraspinal muscle parameters measured on MRI for severe cage subsidence after standalone lateral lumbar interbody fusion

BACKGROUND CONTEXT

The effect of psoas and paraspinal muscle parameters on cage subsidence after minimally invasive techniques, such as standalone lateral lumbar interbody fusion (SA-LLIF), is unknown.

PURPOSE

This study aimed to determine whether the functional cross-sectional area (FCSA) of psoas and lumbar spine extensor muscles (multifidus and erector spinae), and psoas FCSA normalized to the vertebral body area (FCSA/VBA) differ among levels with severe cage subsidence after SA-LLIF when compared to levels without severe cage subsidence.

STUDY DESIGN

Retrospective single center cohort study.

PATIENT SAMPLE

Patients who underwent SA-LLIF between 2008 and 2020 for degenerative conditions using exclusively polyetheretherketone (PEEK) cages, had a lumbar magnetic resonance imaging (MRI) scan within 12 months, a lumbar computed tomography (CT) scan within 6 months prior to surgery, and a postoperative clinical and radiographic follow-up at a minimum of 6 months were included.

OUTCOME MEASURES

Severe cage subsidence.

METHODS

MRI measurements included psoas and combined multifidus and erector spinae (paraspinal) FCSA and FCSA/VBA at the L3-L5 pedicles. Following manual segmentation of muscles on axial T2-weighted images using ITK-SNAP (version 3.8.0), the FCSA was calculated using a custom written program on Matlab (version R2019a, The MathWorks, Inc.) that used an automated pixel intensity threshold method to differentiate between fat and muscle. Mean volumetric bone mineral density (vBMD) at L1/2 was measured by quantitative CT. The primary endpoint was severe cage subsidence per level according to the classification by Marchi et al. Multivariable logistic regression analysis was performed using generalized linear mixed models. All analyses were stratified by biological sex.

RESULTS

95 patients (45.3% female) with a total of 188 operated levels were included in the analysis. The patient population was 92.6% Caucasian with a median age at surgery of 65 years. Overall subsidence (Grades 0-III) was 49.5% (53/107 levels) in men versus 58.0% (47/81 levels) in women (p=.302), and severe subsidence (Grades II-III) was 22.4% (24/107 levels) in men versus 25.9% (21/81 levels) in women (p=.608). In men, median psoas FCSA and psoas FCSA/VBA at L3 and L4 were significantly greater in the severe subsidence group when compared to the non-severe subsidence group. No such difference was observed in women. Paraspinal muscle parameters did not differ significantly between non-severe and severe subsidence groups for both sexes. In the multivariable logistic regression analysis with adjustments for vBMD and cage length, psoas FCSA at L3 (OR 1.002; p=.020) and psoas FCSA/VBA at L3 (OR 8.655; p=.029) and L4 (OR 4.273; p=.043) were found to be independent risk factors for severe cage subsidence in men.

CONCLUSIONS

Our study demonstrated that greater psoas FCSA at L3 and psoas FCSA/VBA at L3 and L4 were independent risk factors for severe cage subsidence in men after SA-LLIF with PEEK cages. The higher compressive forces the psoas exerts on lumbar segments as a potential stabilizer might explain these findings. Additional pedicle screw fixation might be warranted in these patients to avoid severe cage subsidence.