Influence of Skeletal Muscle Mass and Spinal Alignment on Surgical Outcomes for Lumbar Spinal Stenosis

Preoperative Multifidus Muscle Quality is Associated With Patient Reported Outcomes After Lateral Lumbar Interbody Fusion

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

Lateral lumbar interbody fusion (LLIF) commonly involves a transpsoas approach. Despite the association between LLIF, postoperative iliopsoas weakness, and iatrogenic neuropraxia, no study has yet examined the effect of psoas or multifidus muscle quality on patient-reported outcomes (PROs).

METHODS

This study retrospectively reviewed patients who underwent LLIF with 1-year minimum follow-up. Psoas and multifidus muscle qualities were graded on preoperative magnetic resonance imaging using two validated classification systems for muscle atrophy. Average muscle quality was calculated as the mean score from all levels (L1-2 through L5-S1). Univariate and multivariate statistics were utilized to investigate the relationship between psoas/multifidus muscle quality and preoperative, 6-weeks postoperative, and final postoperative PROs.

RESULTS

74 patients (110 levels) with a mean follow-up of 18.71 ± 8.02 months were included for analysis. Greater multifidus atrophy was associated with less improvement on ODI, SF12, and VR12 (P < .05) on univariate analysis. On multivariate analysis, worse multifidus atrophy predicted less improvement on SF12 and VR12 (P < .05).

CONCLUSION

Despite the direct manipulation of the psoas muscle inherent to LLIF, preoperative psoas muscle quality did not affect postoperative outcomes. Rather, the extent of preoperative multifidus fatty infiltration and atrophy was more likely to predict postoperative pain and disability. These findings suggest that multifidus atrophy may be more pertinent than psoas atrophy in its association with patient-reported outcome measures after LLIF.

Psoas Muscle Index as a Predictor of Perioperative Outcomes in Geriatric Patients Undergoing Spine Surgery

STUDY DESIGN

Single-center retrospective study.

OBJECTIVE

The objective of this study was to evaluate the association of psoas muscle mass defined sarcopenia with perioperative outcomes in geriatric patients undergoing elective spine surgery.

METHODS

We included geriatric patients undergoing thoracolumbar spinal surgery. Total psoas surface area (TPA) was measured on preoperative axial computerized tomography or magnetic resonance imaging at the L3 vertebra and normalized to the L3 vertebral body area. Patients were divided into quartiles by normalized TPA, and the fourth quartile (Q4) was compared to quartiles 1-3 (Q1-3). Outcomes included perioperative transfusions, length of stay (LOS), delirium, pseudoarthrosis, readmission, discharge disposition, revision surgery, and mortality.

RESULTS

Of the patients who met inclusion criteria (n = 196), the average age was 73.4 y, with 48 patients in Q4 and 148 patients in Q1-3. Q4 normalized TPA cut-off was <1.05. Differences in Q4 preoperative characteristics included significantly lower body mass index, baseline creatinine, and a greater proportion of females (Table 1). Q4 patients received significantly more postoperative red blood cell and platelet transfusions and had longer ICU LOS (P < .05; Table 2). There was no difference in intraoperative transfusion volumes, delirium, initiation of walking, discharge disposition, readmission, pseudoarthrosis, or revision surgery (Tables 2 and 3). Mortality during follow-up was higher in Q4 but was not statistically significant (P = .075).

CONCLUSION

Preoperative TPA in geriatric patients undergoing elective spine surgery is associated with increased need for intensive care and postoperative blood transfusion. Preoperative normalized TPA is a convenient measurement and could be included in geriatric preoperative risk assessment algorithms.

The Posterior Cranial Vertical Line: A Novel Radiographic Marker for Classifying Global Sagittal Alignment

OBJECTIVE

To define a novel radiographic measurement, the posterior cranial vertical line (PCVL), in an asymptomatic adult population to better understand global sagittal alignment.

METHODS

We performed a multicenter retrospective review of prospectively collected radiographic data on asymptomatic volunteers aged 20-79. The PCVL is a vertical plumb line drawn from the posterior-most aspect of the occiput. The horizontal distances of the PCVL to the thoracic apex (TA), posterior sagittal vertical line (PSVL, posterosuperior endplate of S1), femoral head center, and tibial plafond were measured. Classification was either grade 1 (PCVL posterior to TA and PSVL), grade 2 (PCVL anterior to TA and posterior to PSVL), or grade 3 (PCVL anterior to TA and PSVL).

RESULTS

Three hundred thirty-four asymptomatic patients were evaluated with a mean age of 41 years. Eighty-three percent of subjects were PCVL grade 1, 15% were grade 2, and 3% were grade 3. Increasing PCVL grade was associated with increased age (p < 0.001), C7-S1 sagittal vertical axis (SVA) (p < 0.001), C2-7 SVA (p < 0.001). Additionally, it was associated with decreased SS (p = 0.045), increased PT (p < 0.001), and increased knee flexion (p < 0.001).

CONCLUSION

The PCVL is a radiographic marker of global sagittal alignment that is simple to implement and interpret. Increasing PCVL grade was significantly associated with expected changes and compensatory mechanisms in the aging population. Most importantly, it incorporates cervical alignment parameters such as C2-7 SVA. The PCVL defines global sagittal alignment in adult volunteers and naturally distributes into 3 grades, with only 3% being grade 3 where the PCVL lies anterior to the TA and PSVL.

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.

Preoperative cross-sectional area of psoas muscle correlates with short-term functional outcomes after posterior lumbar surgery

PURPOSE

To determine the optimal level for the measurement of psoas cross-sectional area and examine the correlation with short-term functional outcomes of posterior lumbar surgery.

METHODS

Patients who underwent minimally invasive posterior lumbar surgery were included in this study. The cross-sectional area of psoas muscle was measured at each intervertebral level on T2-weighted axial images of preoperative MRI. Normalized total psoas area (NTPA) (mm2/m2) was calculated as total psoas area normalized to patient height. Intraclass Correlation Coefficient (ICC) was calculated for the analysis of inter-rater reliability. Patient reported outcome measures including Oswestry disability index (ODI), visual analog scale (VAS), short form health survey (SF-12) and patient-reported outcomes measurement information system were collected. A multivariate analysis was performed to elucidate independent predictors associated with failure to reach minimal clinically important difference (MCID) in each functional outcome at 6 months.

RESULTS

The total of 212 patients were included in this study. ICC was highest at L3/4 [0.992 (95% CI: 0.987-0.994)] compared to the other levels [L1/2 0.983 (0.973-0.989), L2/3 0.991 (0.986-0.994), L4/5 0.928 (0.893-0.952)]. Postoperative PROMs were significantly worse in patients with low NTPA. Low NTPA was an independent predictor of failure to reach MCID in ODI (OR = 2.68; 95% CI: 1.26-5.67; p = 0.010) and VAS leg (OR = 2.43; 95% CI: 1.13-5.20; p = 0.022).

CONCLUSION

Decreased psoas cross-sectional area on preoperative MRI correlated with functional outcomes after posterior lumbar surgery. NTPA was highly reliable, especially at L3/4.

Muscle strength rather than appendicular skeletal muscle mass might affect spinal sagittal alignment, low back pain, and health-related quality of life

Sarcopenia is defined as decreasing in muscle strength and mass, and dynapenia is defined as decreasing in muscle strength and maintained muscle mass. This study elucidated the prevalence and characteristics of sarcopenia and dynapenia and evaluate in elderly spinal disorders patients. 1039 spinal disorders patients aged ≥ 65 years were included. We measured age, grip strength, muscle mass, spinal sagittal alignment parameters, low back pain (LBP) scores and health-related quality of life (HR-QoL) scores. Based on the previous reports, patients were categorised into normal group: NG, pre-sarcopenia group: PG, dynapenia group: DG, and sarcopenia group: SG. Pre-sarcopenia, dynapenia, and sarcopenia were found in 101 (9.7%), 249 (19.2%), and 91 (8.8%) patients, respectively. The spinal sagittal alignment parameters, trunk muscle mass, LBP, and HR-QoL scores were significantly worse in DG and SG compared with those in PG and NG. Spinal alignment, trunk muscle mass, and clinical outcomes, including LBP and HR-QoL scores, were maintained in the PG and poor in the DG and SG. Thus, intervention for muscle strength may be a treatment option for changes of spinal sagittal alignment and low back pain.

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.

[Impact of sarcopenia on effectiveness of lumbar decompression surgery in patients with lumbar spinal stenosis]

OBJECTIVE

To investigate the impact of sarcopenia on effectiveness of lumbar decompression surgery in patients with lumbar spinal stenosis.

METHODS

The clinical data of 50 patients with lumbar spinal stenosis who met the selection criteria between August 2017 and December 2020 were retrospectively analyzed. According to the diagnostic criteria of the European Working Group on Sarcopenia in Older People (EWGSOP), based on the calculation of the skeletal muscle index (SMI) at the L ₃ level, SMI<45.4 cm ²/m ² (men) and SMI<34.4 cm ²/m ² (women) were used as the diagnostic threshold, the patients were divided into sarcopenia group (25 cases) and non-sarcopenia group (25 cases). There was no significant difference in gender, age, disease duration, level of lumbar spinal stenosis, surgical fusion level, and comorbidity between the two groups ( P>0.05); the body mass index in sarcopenia group was significantly lower than that in non-sarcopenia group ( t=-3.198, P=0.002). Clinical data of the two groups were recorded and compared, including operation time, intraoperative blood loss, postoperative drainage volume, hospitalization stay, and complications. The visual analogue scale (VAS) scores of low back pain and sciatica and Oswestry disability index (ODI) scores were recorded preoperatively and at last follow-up. The effectiveness was evaluated according to modified MacNab standard.

RESULTS

There was no significant difference between the two groups in terms of operation time, intraoperative blood loss, and postoperative drainage volume ( P>0.05). However, the hospitalization stay in sarcopenia group was significantly longer than that in non-sarcopenia group ( t=2.105, P=0.044). The patients were followed up 7-36 months (mean, 29.7 months). In sarcopenia group, 1 case of dural tear and cerebrospinal fluid leakage occurred during operation, as well as 1 case of internal fixator loosening during follow-up; 1 case of incision exudation and poor healing occurred in each of the two groups, and no adjacent segment degeneration and deep vein thrombosis of lower extremity occurred in the two groups during follow-up. There was no significant difference in the incidence of complications (12% vs. 4%) between the two groups ( χ ²=1.333, P=0.513). VAS scores in low back pain and sciatica as well as ODI scores in two groups significantly improved when compared with preoperative results at last follow-up ( P<0.05). The differences of VAS scores in low back pain and ODI scores before and after operation in sarcopenia group were significantly lower than that in non-sarcopenia group ( P<0.05). However, there was no significant difference of that in VAS scores of sciatica between the two groups ( t=-1.494, P=0.144). According to the modified MacNab standard, the excellent and good rate of the sarcopenia group was 92%, and that of the non-sarcopenia group was 96%, showing no significant difference between the two groups ( χ ² =1.201, P=0.753).

CONCLUSION

Patients with sarcopenia and lumbar spinal stenosis may have longer postoperative recovery time, and the effectiveness is worse than that of non-sarcopenic patients. Therefore, for elderly patients with lumbar spine disease, it is suggested to improve preoperative assessment of sarcopenia, which can help to identify patients with sarcopenia at risk of poor surgical prognosis in advance, so as to provide rehabilitation guidance and nutritional intervention in the perioperative period.

Decreased muscle mass and strength affected spinal sagittal malalignment

PURPOSE

Correction surgeries for spinal malalignment showed good clinical outcomes; however, there were concerns including increased invasiveness, complications, and impact on medico-economics. Ideally, an early intervention is needed. To better understand the patho-mechanism and natural course of spinal alignment, the effect of factors such as muscle mass and strength on spinal sagittal imbalance were determined in a multicenter cross-sectional study.

METHODS

After excluding metal implant recipients, 1823 of 2551 patients (mean age: 69.2 ± 13.8 years; men 768, women 1055) were enrolled. Age, sex, past medical history (Charlson comorbidity index), body mass index (BMI), grip strength (GS), and trunk muscle mass (TM) were reviewed. Spinal sagittal imbalance was determined by the SRS-Schwab classification. Multiple comparison analysis among four groups (Normal, Mild, Moderate, Severe) and multinomial logistic regression analysis were performed.

RESULTS

On multiple comparison analysis, with progressing spinal malalignment, age in both sexes tended to be higher; further, TM in women and GS in both sexes tended to be low. On multinomial logistic regression analysis, age and BMI were positively associated with spinal sagittal malalignment in Mild, Moderate, and Severe groups. TM in Moderate and Severe groups and GS in the Moderate group were negatively associated with spinal sagittal malalignment.

CONCLUSION

Aging, obesity, low TM, and low GS are potential risk factors for spinal sagittal malalignment. Especially, low TM and low GS are potentially associated with more progressed spinal sagittal malalignment. Thus, early intervention for muscles, such as exercise therapy, is needed, while the spinal sagittal alignment is normal or mildly affected.

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

BACKGROUND

Sarcopenia has been found to affect the postoperative outcomes of lumbar surgery. The effect of sarcopenia on the clinical outcomes in patients who underwent stand-alone lateral lumbar interbody fusion (LLIF) has not yet been examined.

OBJECTIVE

To investigate whether sarcopenia affects the Oswestry Disability Index (ODI) and visual analog scale (VAS) score for back pain following single-level stand-alone LLIF.

METHODS

Patients who underwent a single level stand-alone LLIF for lumbar diseases were retrospectively investigated. Sarcopenia was defined according to the diagnostic algorithm recommended by the Asian Working Group for Sarcopenia. Patients were divided into the sarcopenia (SP) and non-sarcopenia (NSP) group. Univariate analysis was used to compare with regards to demographics and clinical outcomes. Multivariate logistic regression was performed to elucidate factors predicting poor clinically improvement.

RESULTS

Sixty-nine patients were enrolled, with 16 and 53 patients in the SP and NSP group respectively. In the SP group, patients were much older (P= 0.002), their body mass index was significantly lower (P< 0.001), the percent of women was higher (P= 0.042), and the skeletal muscle mass index (SMI) (P< 0.001) and gait speed were much lower (P= 0.005). The postoperative ODI scores were much higher and the improvement rate was much lower (both P< 0.001) in the SP group, whereas VAS scores for back pain showed no difference between the two groups. SMI and gait speed had a moderate and weak correlation with the final ODI score, respectively. Low SMI and low gait speed were independently associated with poor clinical outcomes at the final follow-up.

CONCLUSIONS

Sarcopenia impacts the final clinical outcomes of stand-alone LLIF for lumbar diseases. Low SMI and low gait speed were negative impact factors for the clinical improvement after stand-alone LLIF.

Prevalence and Characteristics of Spinal Sagittal Malalignment in Patients with Osteoporosis

Spinal sagittal malalignment due to vertebral fractures (VFs) induces low back pain (LBP) in patients with osteoporosis. This study aimed to elucidate spinal sagittal malalignment prevalence based on VF number and patient characteristics in individuals with osteoporosis and spinal sagittal malalignment. Spinal sagittal alignment, and VF number were measured in 259 patients with osteoporosis. Spinal sagittal malalignment was defined according to the SRS-Schwab classification of adult spinal deformity. Spinal sagittal malalignment prevalence was evaluated based on VF number. In patients without VFs, bone mineral density, bone turnover markers, LBP scores and health-related quality of life (HRQoL) scores of normal and sagittal malalignment groups were compared. In 205 of the 259 (79.2%) patients, spinal sagittal malalignment was detected. Sagittal malalignment prevalence in patients with 0, 1, or ≥2 VFs was 72.1%, 86.0%, and 86.3%, respectively. All LBP scores and some subscale of HRQoL scores in patients without VFs were significantly worse for the sagittal malalignment group than the normal alignment group (p < 0.05). The majority of patients with osteoporosis had spinal sagittal malalignment, including ≥70% of patients without VFs. Patients with spinal sagittal malalignment reported worse LBP and HRQoL. These findings suggest that spinal sagittal malalignment is a risk factor for LBP and poor HRQoL in patients with osteoporosis.

Association between preoperative low muscle mass and psychological factors after surgery among patients with lumbar spinal stenosis: A longitudinal study

It remains controversial whether preoperative low muscle mass affects clinical outcomes after lumbar surgery. Previous studies evaluated outcomes such as pain, quality of life, and disability, but none investigated preoperative low muscle mass and psychological factors. The purpose of this study was to clarify the association between preoperative low muscle mass and postoperative psychological factors in lumbar spinal stenosis (LSS). A longitudinal analysis was performed in 85 consecutive preoperative patients with LSS. Demographic data, leg pain, low back pain, Japanese Orthopaedic Association score, Pain Catastrophizing Scale (PCS) score, Fear-Avoidance Beliefs Questionnaire on Physical Activity (FABQ-PA) score, Hospital Anxiety and Depression Scale (HADS) score, walking velocity, grip strength, and appendicular lean mass were assessed. Muscle mass was measured using bioelectrical impedance analysis. Patients were divided into two groups based on skeletal muscle mass index. These clinical outcomes were evaluated preoperatively and 1 year after surgery. In the 73 patients who were analyzed 1 year after surgery, the prevalence of preoperative low muscle mass was 21.9%. The normal muscle mass group showed significantly improved PCS, FABQ-PA, HADS-anxiety, and HADS-depression scores 1 year after surgery. The low muscle mass group did not demonstrate significantly improved PCS, FABQ-PA, or HADS-depression scores, and had a significantly smaller increase in the FABQ-PA score than the normal muscle mass group. Multivariate analysis showed that low muscle mass was significantly related to change in FABQ-PA score. Our results suggest that preoperative low muscle mass hinders improvement in fear-avoidance beliefs 1 year after surgery.

Impact of Sarcopenia on Degenerative Lumbar Spondylosis

Sarcopenia is characterized by progressive age-related and systematic loss of skeletal muscle mass, strength, and function. It was classified as an independent disease in 2016; thus, there is a sparsity of research on the association of sarcopenia with lower back pain and spinal diseases. Its prevalence is around 10% worldwide and it has been shown to be detrimental to quality of life in the elderly. Sarcopenia can be clinically identified by assessing muscle mass and physical performance measurements to show reduced strength (eg, grip strength chair rise and knee extensions) or function (eg, walking speed or distance). Radiographic imaging techniques such as computed tomography, ultrasound, or magnetic resonance imaging help diagnose sarcopenia in the lumbar spine by measuring either the cross-sectional area or the fatty infiltrate of the lumbar musculature. The presence of sarcopenia in patients preoperatively may lead to worse postoperative outcomes. Research in the treatment options for sarcopenia presurgery is still in its infancy but exercise (both aerobic and resistance exercise have been found to slow down the rate of decline in muscle mass and strength with aging) and nutrition have been utilized to varying success and show great promise in the future.

The Prevalence of Sarcopenia and Its Impact on Clinical Outcomes in Lumbar Degenerative Spine Disease-A Systematic Review and Meta-Analysis

The association of sarcopenia with poor clinical outcomes has been identified in various medical conditions, although there is a lack of quantitative analysis to validate the influence of sarcopenia on patients with lumbar degenerative spine disease (LDSD) from the available literature. Therefore, this systematic review and meta-analysis aimed to summarize the prevalence of sarcopenia in patients with LDSD and examine its impact on clinical outcomes. The electronic databases (PubMed and Embase) were systematically searched from inception through December 2020 for clinical studies investigating the association of sarcopenia with clinical outcomes in patients with LDSD. A random-effects model meta-analysis was carried out for data synthesis. This meta-analysis included 14 studies, comprising 1953 participants. The overall prevalence of sarcopenia among patients with LDSD was 24.8% (95% confidence interval [CI], 17.3%–34.3%). The relative risk of sarcopenia was not significantly increased in patients with LDSD compared with controls (risk ratio, 1.605; 95% CI, 0.321–8.022). The patients with sarcopenia did not experience an increase in low back and leg pain. However, lower quality of life (SMD, −0.627; 95% CI, −0.844–−0.410) were identified postoperatively. Sarcopenia did not lead to an elevated rate of complications after lumbar surgeries. Sarcopenia accounts for approximately one-quarter of the population with LDSD. The clinical manifestations are less influenced by sarcopenia, whereas sarcopenia is associated with poorer quality of life after lumbar surgeries. The current evidence is still insufficient to support sarcopenia as a predictor of postoperative complications.

Preoperative low muscle mass is a predictor of falls within 12 months of surgery in patients with lumbar spinal stenosis

BACKGROUND

Patients with lumbar spinal stenosis (LSS) may be at high risk of falls due to various factors. No effective fall risk assessments or fall prevention measures have been performed for patients with LSS because only a few studies have evaluated falls in these patients. This study aimed to evaluate the incidence and preoperative predictors of falls within 12 months of surgery in patients with LSS.

METHODS

In this prospective study of 82 consecutive preoperative patients with LSS, preoperative demographic data, previous fall history, leg pain, low back pain, Japanese Orthopaedic Association (JOA) score, Hospital Anxiety and Depression Scale (HADS) scores, lower extremity muscle strength, walking speed, grip strength, and muscle mass were assessed at baseline. Falls were assessed at 3, 6, 9, and 12 months after surgery. Participants were categorized as fallers and non-fallers and baseline variables were compared. Binomial logistic regression was used to identify predictors of falls within 12 months of surgery.

RESULTS

Seventy-four patients (90.2%) completed the 12-month follow-up after surgery, of whom 24 patients (32.4%) experienced falls. A higher proportion of fallers were female and had a history of falls compared to non-fallers. Fallers had a significantly lower JOA score and a higher HADS-depression score compared to non-fallers. Fallers had significantly lower tibialis anterior muscle strength, gait speed, grip strength, and skeletal muscle mass index. Fallers had a higher prevalence of low muscle mass compared with non-fallers. The presence of low muscle mass was significantly predictive of falls within 12 months of surgery (odds ratio, 4.46; 95% confidence interval, 1.02-19.63).

CONCLUSIONS

Patients with LSS have a high incidence of falls after surgery and preoperative low muscle mass may be a predictor of postoperative falls.

Handgrip strength correlates with walking in lumbar spinal stenosis

PURPOSE

To examine the relationship between handgrip strength and leg extension power, walking speed, and intermittent claudication for lumbar spinal stenosis (LSS) using computed tomography.

METHODS

We examined patients who underwent laminectomy for LSS from June 2015 through March 2018. Before spine surgery, we evaluated walking distance, handgrip strength, leg extension power (LEP), 10-m walk test (time and steps), psoas muscle index (PMI), and the area of both total and multifidus muscle using plain computed tomography imaging at the third lumbar level. Handgrip strength was compared with comorbidities including anemia, diabetes, hypertension, marital status, etc. RESULTS: There were 183 patients (55 female, 128 male) with a mean age of 70.5 years. Handgrip strength significantly correlated with LEP (P < 0.001, r = 0.723), walking speed (P < 0.001, r = - 0.269), 10-m walking test (steps) (P < 0.001, r = - 0.352), area of skeletal muscle at L3 level (P < 0.001, r = 0.469), area of psoas muscle (P < 0.001, r = 0.380), PMI (P < 0.001, r = 0.253), and intermittent claudication. Age, height, and weight were correlated with handgrip strength, but BMI was not correlated. Handgrip strength was significantly reduced by anemia, hypertension, and single marital status.

CONCLUSIONS

The more handgrip strength patients with LSS have, the more LEP, the faster walking speed, the greater area of psoas and skeletal muscle, the fewer steps for a 10-m walk they have, and the longer walking distance. Age, height, and weight were associated with handgrip strength, but BMI has no association. Low handgrip strength was related to comorbidities including anemia, hypertension, and marital status.

Novel Insights into the Pathogenesis of Spinal Sarcopenia and Related Therapeutic Approaches: A Narrative Review

Spinal sarcopenia is a complex and multifactorial disorder associated with a loss of strength, increased frailty, and increased risks of fractures and falls. In addition, spinal sarcopenia has been associated with lumbar spine disorders and osteoporosis, which renders making decisions on treatment modalities difficult. Patients with spinal sarcopenia typically exhibit lower cumulative survival, a higher risk of in-hospital complications, prolonged hospital stays, higher postoperative costs, and higher rates of blood transfusion after thoracolumbar spine surgery. Several studies have focused on the relationships between spinal sarcopenia, appendicular muscle mass, and bone-related problems-such as osteoporotic fractures and low bone mineral density-and malnutrition and vitamin D deficiency. Although several techniques are available for measuring sarcopenia, each of them has its advantages and shortcomings. For treating spinal sarcopenia, nutrition, physical therapy, and medication have been proven to be effective; regenerative therapeutic options seem to be promising owing to their repair and regeneration potential. Therefore, in this narrative review, we summarize the characteristics, detection methodologies, and treatment options for spinal sarcopenia, as well as its role in spinal disorders.

Relationship between sarcopenia and pain catastrophizing in patients with lumbar spinal stenosis: A cross-sectional study

Objectives

The purpose of this study is to clarify the psychological factors related to sarcopenia in patients with lumbar spinal stenosis (LSS).

Methods

This cross-sectional study included 72 patients with LSS (38 males and 34 females; mean age, 70.4 ± 6.9 years). Demographic data, lower extremity pain, back pain, Japanese Orthopaedic Association score, Pain Catastrophizing Scale (PCS) score, Hospital Anxiety and Depression Scale (HADS) score, Fear-Avoidance Beliefs Questionnaire score, walking velocity, grip strength, walking distance, and appendicular muscle mass were assessed. Muscle mass was measured using bioelectrical impedance analysis. Patients were grouped based on sarcopenia status according to skeletal muscle mass index.

Results

The prevalence of sarcopenia was 13.9% (10 of 72 patients). Sarcopenia was significantly more common in females. The incidence of dyslipidemia and cardiovascular disease were significantly higher in the sarcopenia group. The sarcopenia group had lower body weight, body mass index, grip strength, and walking distance than the control group. The sarcopenia group had higher PCS scores and HADS-anxiety scores. Multivariate analysis identified body weight, dyslipidemia, walking distance, and PCS score as significantly related to sarcopenia.

Conclusions

Pain catastrophizing might be the most relevant psychological factor in sarcopenia. Evaluation of both physical function and pain catastrophizing is needed when investigating sarcopenia in LSS.

Impact of Sarcopenia on Clinical Outcomes of Minimally Invasive Lumbar Decompression Surgery

The purpose of this study was to clarify the clinical impact of sarcopenia on the outcome of minimally invasive lumbar decompression surgery. The records of 130 patients who were >65 years and underwent minimally invasive lumbar decompression surgery were retrospectively reviewed. We collected the Japanese Orthopaedic Association (JOA) score before surgery and at the final follow-up and measured appendicular muscle mass using bioimpedance analysis, hand-grip strength and gait speed. We diagnosed the patients with sarcopenia, dynapenia and normal stages using the European Working Group on Sarcopenia in Older People definition and used cutoff thresholds according to the algorithm set by the Asian Working Group for Sarcopenia. The average age of patients undergoing surgery was 76.9 years old. The JOA score improved from 12.6 points preoperatively to 24.3 points at final follow up. The prevalence of the sarcopenia, dynapenia and normal stages was 20.0, 31.6 and 43.8%. Clinical outcomes, such as JOA score, JOA score improvement ratio, visual analog scale for low back pain, leg pain and numbness, were not significantly different among each group. Multiple regression analysis showed that preoperative JOA score and low physical performance (low gait speed) were independently associated with poor clinical outcomes. The JOA score improved after minimally invasive lumbar decompression surgery even when the patients were diagnosed as being at different stages of sarcopenia. Low physical performance had the greater clinical impact on the clinical outcome of lumbar surgery than low skeletal muscle index.