Ciliary Hedgehog Signaling Restricts Injury-Induced Adipogenesis.

Injured skeletal muscle regenerates, but with age or in muscular dystrophies, muscle is replaced by fat. Upon injury, muscle-resident fibro/adipogenic progenitors (FAPs) proliferated and gave rise to adipocytes. These FAPs dynamically produced primary cilia, structures that transduce intercellular cues such as Hedgehog (Hh) signals. Genetically removing cilia from FAPs inhibited intramuscular adipogenesis, both after injury and in a mouse model of Duchenne muscular dystrophy. Blocking FAP ciliation also enhanced myofiber regeneration after injury and reduced myofiber size decline in the muscular dystrophy model. Hh signaling through FAP cilia regulated the expression of TIMP3, a secreted metalloproteinase inhibitor, that inhibited MMP14 to block adipogenesis. A pharmacological mimetic of TIMP3 blocked the conversion of FAPs into adipocytes, pointing to a strategy to combat fatty degeneration of skeletal muscle. We conclude that ciliary Hh signaling by FAPs orchestrates the regenerative response to skeletal muscle injury.

Proximal humeral fractures: association between displacement and fatty degeneration of the supraspinatus muscle.

INTRODUCTION: To evaluate the relationship between initial displacement in proximal humeral fractures and fatty degeneration of the rotator cuff measured by CT according to the Goutallier classification. MATERIAL AND METHODS: This cross-sectional observational study evaluated patients with proximal humeral fractures over a six-month period. The study included patients ≥ 18 years old with complete radiological views (anteroposterior, lateral, and Grashey) and a CT scan of the affected shoulder; previous fracture or ipsilateral shoulder surgery were excluded. Neer's classification system and Goutallier stages were used to evaluate the patients. Demographic data were collected and, two groups were analysed according to age (≤ 50 years and > 50 years). RESULTS: Sixty-two patients were included (m = 36, f = 26, ratio 1.3:1); seven patients were excluded. Male patients (36, 58.1%), patients older than 50 years (33, 53.2%) and a low-energy injury mechanism (36, 58.1%) were the most frequent cases. According to the Neer system, the most common proximal humerus fracture was fracture-dislocation in 17 (27.4%) cases. The most common stage in Goutallier's classification was I (some fatty streaks) in 22 (35.4%) cases. Younger patients (≤ 50 years) had more displaced fractures with low fatty degeneration (p = < 0.001) than older patients (> 50 years), who had minimally displaced fractures with greater fatty degeneration (p = 0.567). CONCLUSIONS: High-energy mechanisms are associated with younger patients and a more displaced fracture according to the Neer classification. Older patients had a more advanced Goutallier stage and lesser displaced fracture. We should consider a more aggressive approach in the treatment of non-displaced fractures in elderly patients, less conservative and more surgical management, to obtain a better clinical evolution after the treatment of these kinds of fractures. LEVEL OF EVIDENCE: IV.

Significance of paraspinal muscle quality in risk between single and multiple osteoporotic vertebral fractures.

PURPOSE: To compare paraspinal muscle quality between patients with single and multiple osteoporotic vertebral fractures (OVFs) and evaluate the role of the paraspinal muscles in OVFs. METHODS: A total of 262 consecutive patients with OVFs were retrospectively analyzed in two groups: those with single OVF (n = 173) and those with multiple OVFs (n = 89). The cross-sectional area (CSA) and fatty degeneration of the paraspinal muscles were calculated from axial T2-weighted magnetic resonance imaging at the level of the L4 upper endplate by manual tracing in ImageJ software. Pearson's correlation analysis was performed to analyze correlations of paraspinal muscle quality to multiple OVFs. RESULTS: FD in all the paraspinal muscles was significantly higher in the multiple OVF group than the single OVF group (all p < 0.005). The functional CSA (fCSA) of the paraspinal muscles was significantly lower in the multiple OVF group than the single OVF group (all Ps < 0.001), except for the erector spine (p = 0.304). The Pearson's correlation analysis showed significant positive inter-correlations for the fCSAs of all the paraspinal muscles and the occurrence of multiple OVFs. CONCLUSIONS: The pure muscle volumes of the multifidus, psoas major, and quadratus lumborum were lower in patients with multiple OVFs than in those with a single OVF. Furthermore, the inter-correlation among all the paraspinal muscles indicate that the muscle-bone crosstalk profoundly existed in vertebral fracture cascade. Therefore, special attention to paraspinal muscle quality is needed to prevent progression to multiple OVFs.

Definition of irreparable rotator cuff tear: a scoping review of prospective surgical therapeutic trials to evaluate current practice.

BACKGROUND: The definition of irreparable rotator cuff tear (IRCT) is controversial. This scoping review provides definitions used to describe IRCT in the literature. This scoping review (1) identified criteria used in the definition of IRCT and (2) investigated the current state of those criteria in prospective surgical therapeutic trials. METHODS: This scoping review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews. PubMed, Scopus, and Web of Science were searched in March 2023. Studies were screened against predetermined inclusion and exclusion criteria. Criteria regarding clinical symptoms, preoperative images, and intraoperative findings were captured respectively. RESULTS: A total of 41 prospective studies were eligible for inclusion, and 35 studies (85.4%) defined IRCT. IRCT was defined on the basis of the following main criteria: preoperative image findings (28/35), intraoperative findings (24/35), and symptoms (16/35). With regard to preoperative images, IRCT was mainly defined on the basis of retraction of the tendon in the coronal plane (22/28), the severity of fatty degeneration (19/28), and ruptured tendon number or width of the defect in the sagittal plane (17/28). CONCLUSION: This scoping review highlights the lack of a standardized definition for IRCT in clinical practice, with common predictive criteria including a duration of over 6 months, retraction beyond 5 cm, Goutallier grade 3 fatty infiltration, and the rupture of two or more tendons. However, surgeons should apply more than one criterion when examining preoperative images and confirm reparability during surgery. A more objective manner of evaluating intraoperative reparability is necessary.

Risk factors for residual back pain following percutaneous vertebral augmentation: the importance of paraspinal muscle fatty degeneration.

PURPOSE: Residual back pain (RBP) after percutaneous vertebral augmentation (PVA) still exists considerable, and it even affects daily life due to moderate or severe back pain. A variety of risk factors have been previously identified for developing residual back pain. However, there are conflicting reports regarding the association between sarcopenia and residual back pain. As such, the aim of this study was to investigate whether paraspinal muscle fatty degeneration is a predictor of residual back pain. METHODS: We retrospectively reviewed the medical records of patients with single-segment OVCF who underwent PVA from January 2016 to January 2022. Patients were divided into RBP group (86 patients) and control group (790 patients) according to whether the visual analog scale (VAS) score ≥ 4. The clinical and radiological data were analyzed. Paraspinal musculature fatty degeneration was measured using the Goutallier classification system (GCS) at the L4 - 5 intervertebral disc level. Univariate and multivariate logistic regression analyses were performed to identify risk factors. RESULTS: The results of multivariate logistical regression analysis revealed that posterior fascia injury (odds ratio (OR) = 5.23; 95% confidence interval (CI) 3.12-5.50; P < 0.001), as regards paraspinal muscle fatty degeneration, including Goutallier grading (OR = 12.23; 95% CI 7.81-23.41; P < 0.001), fCSA (OR = 3.06; 95% CI 1.63-6.84; P = 0.002), fCSA/CSA (%) (OR = 14.38; 95% CI 8.80-26.29; P < 0.001), and facet joint violation (OR = 8.54; 95% CI 6.35-15.71; P < 0.001) were identified as independent risk factors for RBP. CONCLUSIONS: Posterior fascia injury, paraspinal muscle fatty degeneration, and facet joint violation were identified as independent risk factors for RBP, with paraspinal muscle fatty degeneration playing an important role.

Fatty infiltration in cervical extensor muscle: is there a relationship with cervical sagittal alignment after anterior cervical discectomy and fusion?

PURPOSE: To investigate the relationship between the preoperative paraspinal Goutalier grade of fatty infiltration and postoperative cervical sagittal alignment in patients undergoing anterior cervical discectomy and fusion (ACDF). METHODS: A total of 101 patients who underwent single-level ACDF with the Zero-profile implant system between March 2011 and April 2020 were included in this study. Cervical sagittal alignment parameters, including the C2-C7 Cobb angle, functional spinal unit (FSU) angle, cervical sagittal vertical axis (SVA), and T1 slope (T1S), were assessed. Preoperative magnetic resonance images were used to classify patients according to Goutalier grade. Clinical outcomes including Neck Disability Index (NDI) scores, Japanese Orthepaedic Association (JOA) scores and Visual Analogue Scale (VAS) scores were collected and analyzed. RESULTS: According to the Goutalier grade, 33 patients were classified as Goutalier 0-1 (Group A), 44 were classified as Goutalier 1.5-2 (Group B), and 24 were classified as Goutalier 2.5-4.0 (Group C). The mean age among the three groups showed significant differences (P = 0.007). At the last follow-up, the C2-C7 Cobb angle, FSU angle, and T1S improved after the surgery among the groups. Although there were varying degrees of loss of curvature among the different groups during the follow-up period, the postoperative cervical sagittal alignment parameters demonstrated no statistical differences among the three groups (P > 0.05). In addition, patients in all groups experienced significant relief of their symptoms, and the clinical scores were comparable among the groups (P > 0.05). CONCLUSION: The complex nature of anterior cervical surgery requires surgical attention both in decompression and sagittal alignment. Our study demonstrates satisfactory postoperative cervical sagittal alignment of patients despite different grades of fatty infiltration of the multifidus muscle following single-level ACDF. Based on our results, the improvement and maintenance of cervical sagittal alignment after ACDF remains a complex problem that spine surgeons should consider before surgery.

A new radiological index for the assessment of higher body fat status and lumbar spine degeneration.

OBJECTIVE: Obesity has been proposed as a risk factor for low back pain (LBP) and intervertebral disc degeneration (IVDD). Even though body mass index (BMI) is used as a parameter for obesity, it could not represent percentage and distribution of the body fat. Subcutaneous fat tissue thickness (SFTT) was proposed as one of the magnetic resonance imaging (MRI) parameters to evaluate the percentage of the body fat. In this study, we aimed to find out whether SFTT at lower back correlated with LBP and spine degeneration. MATERIALS AND METHODS: We retrospectively reviewed a database of the patients with LBP. Concomitantly, asymptomatic control subjects were retrieved. Patients and control subjects were evaluated in terms of IVDD and Modic changes at all lumbar levels on MRI. SFTT was measured both on MRI and computed tomography (CT) scans, where applicable. RESULTS: SFTT at the lumbar spine had moderate-to-strong correlations with BMI. SFTT at L1-L2 level was significantly associated with severe IVDD at L5-S1 level, and Modic changes at L4-L5 and L5-S1 levels. BMI had no significant association with severe IVDD and Modic changes at lumbar spine. BMI and mean SFTT of all lumbar levels had ORs of 0.735 (95% CI: 0.631-0.857, p < 0.001) and 1.389 (95% CI: 1.266-1.524, p < 0.001) in predicting symptomatic subjects with LBP. CONCLUSION: SFTT at upper lumbar levels could predict severe IVDD and Modic changes better than BMI, specifically in men. SFTT was better than BMI in predicting a symptomatic patient with LBP.

Preoperative paraspinal and psoas major muscle atrophy and paraspinal muscle fatty degeneration as factors influencing the results of surgical treatment of lumbar disc disease.

INTRODUCTION: There is a growing number of publications highlighting sarcopenia and myosteatosis as poor prognosic factors for treatment results in oncological patients. The decrease in the cross-sectional area (CSA) of the multifidus muscle and muscle steatosis is associated with lumbar disc herniation and low back/limb pain. Nevertheless, no studies have analyzed the influence of the above parameters on patient satisfaction, pain decrease and return to daily activities. The aim of the study was to verify whether decreased preoperative CSA of the paraspinal and psoas major muscles and their fatty degeneration (myosteatosis) may influence the outcome of surgical treatment of lumbar disc disease (LDD). MATERIALS AND METHODS: One hundred and one patients with LDD undergoing open microdiscectomy were enrolled in the analysis. Relative cross-sectional areas (rCSA) of the paraspinal and psoas major muscles as well as their fatty degeneration were measured. Patients were assessed according to the validated Polish versions of the EURO EQ-5D, Core Outcome Measure Index (COMI), Oswestry Disability Index (ODI) and Visual Analog Scale (VAS) 1 and 6 months postoperatively. The association between the variables was calculated using Pearson r and Spearman rank correlation. The Kruskal-Wallis test was used to compare the results between the groups with different rCSA of paraspinal and psoas major muscles and a different degree of paraspinal muscle myosteatosis. RESULTS: Fatty degeneration of the paraspinal muscles correlated with better outcomes 1 and 6 months postoperatively according to ODI (P = 0.003 and P = 0.027, respectively). Patients with higher rCSA of the paraspinal and psoas major muscles achieved better results on the EURO EQ-5D scale (P = 0.0289 and P = 0.0089, respectively). Higher rCSA of the paraspinal and psoas major muscles did not correlate with better outcomes measured using ODI, COMI and VAS scales (P ≥ 0.072). CONCLUSION: The degree of fatty degeneration of the paraspinal muscles correlates with better outcomes 1 and 6 months after microdiscectomy.

Impact of fatty degeneration on the functional outcomes of 38 patients undergoing surgical repair of gluteal tendon tears.

BACKGROUND: Gluteal tendon tears (GTT) can cause pain and weakness of the hip. We analyze the impact of gluteal muscle fatty degeneration, atrophy and tear morphology on clinical outcomes of surgical repair. METHODS: All sequential patients receiving surgical repair of GTTs via anchor sutures between 1/2015 and 11/2018 were retrospectively identified. MRIs were reviewed by a radiologist for tendon retraction, muscle atrophy and tear size. The Goutallier-Fuchs Classification (GFC) was used to quantify fatty degeneration as < 2° or ≥ 2°. Demographic and clinical variables were abstracted from the electronic records. The surveys HHS Section 1 and HOOS Jr. were obtained at last follow-up. The Pearson correlation and one-way ANOVA tests served for statistical analysis of clinical variance. RESULTS: 38 patients were identified, 29 (76.3%) were female. The average age was 67. Of the 11 (28.9%) patients with a prior hip arthroplasty 87.5% of primary THAs had a direct lateral approach. 29 (76.3%) patients were treated open and 9 (23.7%) arthroscopically. At an average follow-up of 20.9 months, patients reported a significant improvement in pain (97%), analgesic use (85.7%), limp (52.6%) and abduction strength (54.2%) (all: P ≤ 0.01). GFC ≥ 2° were associated with significantly worse outcomes in terms of limp (0.19/3 vs. 1.2/3, P = 0.05), HHS-S1 (58.19 vs. 71.68, P = 0.04) and complication rates (37.5% vs. 0%, P = 0.02). There was a strong correlation between tear retraction (P = 0.005), tear size (P = 0.009) and muscle atrophy (P = 0.001) with GFC ≥ 2° but not with clinical outcomes. GFC ≥ 2° was strongly related to lateral THA exposures (P < 0.001). Surgical approach had no impact on clinical outcomes. CONCLUSION: While fatty degeneration can negatively impact functional outcomes, pain relief is reliably achieved. Tear morphology and muscle atrophy did not correlate with outcomes in this patient cohort. Patients should be counseled to expect a residual limp after surgery if they have GFC ≥ 2° on MRI.

Degenerative lumbar scoliosis patients with proximal junctional kyphosis have lower muscularity, fatty degeneration at the lumbar area.

PURPOSE: To assess the lumbar muscle conditions on the incidence of proximal junctional kyphosis (PJK) after long-level correction and instrumentation surgery for degenerative lumbar scoliosis (DLS) patients with a minimum 2-year follow-up. METHODS: Eighty-four DLS patients undergoing long instrumented fusion surgery (≥ 5 vertebrae) were retrospectively studied. According to the occurrence of PJK at the final follow-up, patients were divided into the PJK group and the Non-PJK group. Patient characteristics, surgical variables and radiographic parameters were analyzed statistically. The lumbar muscularity (cross-sectional area of muscle-disc ratio × 100) and fatty degeneration (signal intensity of muscle-subcutaneous fat ratio × 100) were evaluated on magnetic resonance imaging . RESULTS: The prevalence of PJK was 20.24%. Gender, age at surgery, body mass index, uppermost instrumented vertebrae level, fusions extending to the sacrum, and levels fused were not significantly different between the groups. Lower bone mineral density, smaller functional cross-sectional area (FCSA) of paraspinal extensor muscles (PSE), higher lean muscle-fat index and total muscle-fat index of PSE, greater preoperative thoracolumbar kyphosis (TLK), smaller preoperative sacral slope (SS), larger preoperative sagittal vertical axis were identified in PJK group. Logistic regression analysis showed that osteoporosis, preoperative TLK > 15°, SS > 24°, FCSA of PSE > 138.75, and total muscle-fat index of PSE > 4.08 were independently associated with PJK. The final follow-up VAS score for back pain was higher, and SRS-22 subcategories of pain, function, self-image, and total score were significantly lower in the PJK group. CONCLUSION: Osteoporosis, lower lumbar muscularity and higher fatty degeneration, preoperative greater TLK and smaller SS were found to be strongly associated with the presence of PJK in DLS.

A comparison of the bilateral decompression via unilateral approach versus conventional approach transforaminal lumbar interbody fusion for the treatment of lumbar degenerative disc disease in the elderly.

BACKGROUND: Bilateral decompression via unilateral approach (BDUA) is an effective surgical approach for treating lumbar degenerative diseases. However, no studies of prognosis, especially the recovery of the soft tissue, have reported using BDUA in an elderly population. The aims of these research were to investigate the early efficacy of the bilateral decompression via unilateral approach versus conventional approach transforaminal lumbar interbody fusion (TLIF) for the treatment of lumbar degenerative disc disease in the patients over 65 years of age, especially in the perioperative factors and the recovery of the soft tissue. METHODS: The clinical data from 61 aging patients with lumbar degenerative disease who received surgical treatment were retrospectively analyzed. 31 cases who received the lumbar interbody fusion surgery with bilateral decompression via unilateral approach (BDUA) were compared with 30 cases who received conventional approach transforaminal lumbar interbody fusion. The radiographic parameters were measured using X-ray including lumbar lordosis angle and fusion rate. Japanese Orthopedic Association (JOA), Visual Analogue Scale (VAS) and Oswestry Disability Index (ODI) scores were used to evaluate the clinical outcomes at different time points. Fatty degeneration ratio and area of muscle/vertebral body were used to detect recovery of soft tissue. RESULTS: The BDUA approach group was found to have significantly less intraoperative blood loss(p < 0.05) and postoperative drainage(p < 0.05) compared to conventional approach transforaminal lumbar interbody fusion group. Symptoms of spinal canal stenosis and nerve compression were significantly relieved postoperatively, as compared with the preoperative state. However, the opposite side had a lower rate of fatty degeneration (9.42 ± 3.17%) comparing to decompression side (11.68 ± 3.08%) (P < 0.05) six months after surgery in the BDUA group. While there were no significant differences (P > 0.05) in two sides of conventional transforaminal lumbar interbody fusion approach group six months after surgery. CONCLUSIONS: Bilateral decompression via unilateral approach (BDUA) is able to reduce the intraoperative and postoperative body fluid loss in the elderly. The opposite side of decompression in BDUA shows less fatty degeneration in 6 months, which indicates better recovery of the soft tissue of the aging patients.

An assessment of morphological and pathological changes in paravertebral muscle degeneration using imaging and histological analysis: a cross-sectional study.

BACKGROUND: The high signal of paravertebral muscle (PVM) on T2-weighted image (T2WI) is usually considered to be fatty degeneration. However, it is difficult to distinguish inflammatory edema from fatty degeneration on T2WI. The purpose of this study was to identify different types of PVM high signal in patients with low back pain (LBP) through magnetic resonance imaging (MRI) and histology. METHODS: Seventy patients with LBP underwent MRI. The signal change of multifidus both on T2WI and fat suppression image (FSI) was quantified by Image J. Furthermore, 25 of the 70 patients underwent surgery for degenerative lumbar disease and their multifidus were obtained during the operation. Histological analysis of the samples was performed by HE staining. RESULT: Three types of PVM signal changes were identified from the MRI. Type 1 (n = 36) indicated fatty degeneration characterized by a high signal on T2WI and low signal on FSI. High signal on both T2WI and FSI, signifying type 2 meant inflammatory edema (n = 9). Type 3 (n = 25) showed high signal on T2WI and partial signal suppression on FSI, which meant a combination of fatty degeneration and inflammatory edema. Histological results were consistent with MRI. Among the 25 patients who underwent surgery, type 1 (n = 14) showed adipocytes infiltration, type 2 (n = 3) showed inflammatory cells infiltration and type 3 (n = 8) showed adipocytes and inflammatory cells infiltration. CONCLUSION: From our results, there are three types of pathological changes in patients with PVM degeneration, which may help to decide on targeted treatments for LBP.

MARS MRI assessment of fatty degeneration of the gluteal muscles in patients with THA: reliability and accuracy of commonly used classification systems.

INTRODUCTION: Fatty degeneration of the gluteal muscles on metal artefact reduction sequence (MARS) MRI has been shown to correlate with poor functional outcomes, particularly in patients with total hip arthroplasty (THA). Standardized, reliable classification systems that permit assessment of fatty gluteal infiltration are needed for clinical decision making. This study aimed to compare the reproducibility and accuracy of commonly used MRI classification systems for fatty gluteal atrophy in THA patients. METHODS: MARS magnetic resonance images of 82 patients with unilateral THA were analysed by three independent trained observers. The readers evaluated fatty degeneration of the gluteus minimus, gluteus medius, and gluteus maximus according to 3 widely used classification systems: Goutallier, Quartile, and Bal and Lowe. Interobserver and intraobserver repeatability were determined using the weighted Kappa test. Quantitative evaluation of the proportion of intramuscular fat based on MR signal intensities was obtained and represented the gold standard. RESULTS: Mean interobserver agreement for the Quartile classification system (0.93) was higher compared with Goutallier classification system (0.87) and the Bal and Lowe classification system (0.83; range 0.79-0.88; p = 0.04). Intraobserver repeatability was significantly higher for the Quartile classification system (weighted kappa 0.91, 0.89, 0.85) compared with the Bal and Lowe classification system (weighted kappa 0.83, 0.77, 0.75; p < 0.01) and Goutallier classification system (weighted kappa 0.83, 0.77, 0.75; p = 0.04). Agreement with the gold standard measurements was significantly higher in the Quartile classification system (0.88, 0.84, 0.81) compared with the Goutallier classification system (0.80, 0.77, 0.78; p = 0.02) and Bal and Lowe classification system (0.76, 0.74, 0.73; p < 0.01). DISCUSSION: This study directly compared three clinically used MRI classification systems for fatty gluteal muscle atrophy in THA patients. Our findings demonstrate that although all three classification systems demonstrate good reproducibility and accuracy, the Quartile classification system is superior to the others in terms of intraobserver reliability and accuracy to quantify fatty gluteal degeneration in THA patients.

Reduced mitochondrial lipid oxidation leads to fat accumulation in myosteatosis.

Myosteatosis is the pathologic accumulation of lipid that can occur in conjunction with atrophy and fibrosis following skeletal muscle injury. Little is known about the mechanisms by which lipid accumulates in myosteatosis, but many clinical studies have demonstrated that the degree of lipid infiltration negatively correlates with muscle function and regeneration. Our objective was to determine the pathologic changes that result in lipid accumulation in injured muscle fibers. We used a rat model of rotator cuff injury in this study because the rotator cuff muscle group is particularly prone to the development of myosteatosis after injury. Muscles were collected from uninjured controls or 10, 30, or 60 d after injury and analyzed using a combination of muscle fiber contractility assessments, RNA sequencing, and undirected metabolomics, lipidomics, and proteomics, along with bioinformatics techniques to identify potential pathways and cellular processes that are dysregulated after rotator cuff tear. Bioinformatics analyses indicated that mitochondrial function was likely disrupted after injury. Based on these findings and given the role that mitochondria play in lipid metabolism, we then performed targeted biochemical and imaging studies and determined that mitochondrial dysfunction and reduced fatty acid oxidation likely leads to the accumulation of lipid in myosteatosis.-Gumucio, J. P., Qasawa, A. H., Ferrara, P. J., Malik, A. N., Funai, K., McDonagh, B., Mendias, C. L. Reduced mitochondrial lipid oxidation leads to fat accumulation in myosteatosis.

Sarcopenia and fatty degeneration of paraspinal muscle associated with increased sagittal vertical axis in the elderly: a cross-sectional study in 71 female patients.

PURPOSE: Both increased sagittal vertical axis (SVA) and sarcopenia affect performance of daily activities and morbidity in the elderly; however, little is known regarding their relationship. The aim of this study was to analyze the association between sarcopenia and increased SVA. METHODS: This retrospective study included 71 female patients aged between 60 and 85 years. Entire-spine radiography was used to measure radiological parameters. A bioelectrical impedance analyzer was used to measure the skeletal muscle mass index (SMI). Gait velocity (GV) and hand grip strength (HGS) were examined as well. Lumbar spine magnetic resonance imaging was employed to measure the functional cross-sectional area (FCSA) and fat signal fraction (FSF) of the paraspinal muscle as well. The subjects were divided into two groups according to the SVA (group I; SVA > 50 mm and group II; SVA ≤ 50 mm). RESULTS: The group I showed lower GV, HGS, and SMI than the group II (p < 0.001, < 0.001, and = 0.001, respectively). The prevalence of sarcopenia was higher in the group I (56.7%) than in the group II (17.1%) (p = 0.001). The group I also showed lower FCSA and higher FSF than the group II (p < 0.001). In multivariate analysis, the FSF (odds ratio 1.308, p = 0.004) and HGS (odds ratio 0.792, p = 0.023) were correlated with increased SVA. In addition, the BMI (odds ratio 0.756, p = 0.037), SVA (odds ratio 1.051, p = 0.031), and FCSA (odds ratio 0.995, p = 0.012) were correlated with sarcopenia. CONCLUSION: Sarcopenia and fatty degeneration of paraspinal muscle are closely related to increased SVA in the elderly.

In vivo testing of an injectable matrix gel for the treatment of shoulder cuff muscle fatty degeneration.

INTRODUCTION: Extracellular matrix (ECM) gels have shown efficacy for the treatment of damaged tissues, most notably cardiac muscle. We hypothesized that the ECM gel prepared from skeletal muscle could be used as a treatment strategy for fatty shoulder cuff muscle degeneration. METHODS: We conducted experiments to (1) evaluate host biocompatibility to ECM gel injection using a rat model and (2) examine the effect of ECM gel injection on muscle recovery after delayed repair of a released supraspinatus (SSP) tendon using a rabbit model. RESULTS: The host biocompatibility to the ECM gel was characterized by a transient rise (first 2 weeks only) in several genes associated with macrophage infiltration, matrix deposition, and inflammatory cytokine production. By 8 weeks all genes had returned to baseline levels and no evidence of fibrosis or chronic inflammation was observed from histology. When gel injection was combined with SSP tendon repair, we observed a significant reduction (7%) in SSP muscle atrophy (24 + 3% reduction from uninjured) when compared with treatment with tendon repair only (31 + 7% reduction). Although fatty degeneration was elevated in both treatment groups, fat content trended lower (2%) in response to combined tendon repair and intramuscular ECM injection (4.1 + 2.1%) when compared with tendon repair only (6.1 + 2.9%). Transcriptome analysis revealed adipogenesis and osteoarthritis pathway activation in the repair only group. These key pathways were abrogated in response to treatment using combined repair plus gel. DISCUSSION: The findings suggest that ECM injection had a modest but positive effect on muscle mass, fatty degeneration, and key cellular signaling pathways.

Equivalent Mid-Term Results of Open vs Endoscopic Gluteal Tendon Tear Repair Using Suture Anchors in Forty-Five Patients.

BACKGROUND: Little is known about the relative efficacy of open (OGR) vs endoscopic (EGR) gluteal tendon repair of gluteal tendon tears in minimizing pain and restoring function. Our aim is to compare these 2 surgical techniques and quantify their impact on clinical outcomes. METHODS: All patients undergoing gluteal tendon tear repair at our institution between 2015 and 2018 were retrospectively reviewed. Pain scores, limp, hip abduction strength, and the use of analgesics were recorded preoperatively and at last follow-up. The Hip disability and Osteoarthritis Outcome Score Junior and Harris Hip Score Section1 were obtained at last follow-up. Fatty degeneration was quantified using the Goutallier-Fuchs Classification (GFC). Statistical analysis was conducted using one-way analysis of variance and t-tests. RESULTS: Forty-five patients (mean age 66, 87% females) met inclusion criteria. Average follow-up was 20.3 months. None of the 10 patients (22%) undergoing EGR had prior surgery. Of 35 patients (78%) undergoing OGR, 12 (27%) had prior hip replacement (75% via lateral approach). The OGRs had more patients with GFC ≥2 (50% vs 11%, P = .02) and used more anchors (P = .03). Both groups showed statistical improvement (P ≤ .01) for all outcomes measured. GFC >2 was independently associated with a worst limp and Harris Hip Score Section 1 score (P = .05). EGR had a statistically higher opioid use reduction (P < .05) than OGR. Other comparisons between EGR and OGR did not reach statistical significance. CONCLUSION: In this series, open vs endoscopic operative approach did not impact clinical outcomes. More complex tears were treated open and with more anchors. Fatty degeneration adversely impacted outcomes. Although further evaluation of the efficacy of EGR in complex tears is indicated, both approaches can be used successfully.

Relationship between postoperative retear and preoperative fatty degeneration in large and massive rotator cuff tears: quantitative analysis using T2 mapping.

BACKGROUND: Fatty degeneration of the rotator cuff muscles is reported to be associated with retear after rotator cuff repair. The purpose of this study was to assess the relationship between retear and preoperative fatty degeneration, as quantified by T2 mapping. METHODS: This prospective cohort study included 83 large and 24 massive rotator cuff tears (average age, 67 years; range, 46-82 years). All patients preoperatively underwent T2 mapping magnetic resonance imaging, and T2 values of the supraspinatus and infraspinatus muscles were quantified. Cuff integrity was evaluated with magnetic resonance imaging 1 year postoperatively. Preoperative T2 values were compared between the retear and intact groups. The preoperative Goutallier stage, Constant score, and the shoulder score of the University of California at Los Angeles were also compared between the 2 groups. RESULTS: Retear was found in 32 shoulders (30%). Postoperative Constant and University of California at Los Angeles scores were significantly higher in intact shoulders than in retear shoulders (P < .001 for both). Mean preoperative T2 values of supraspinatus and infraspinatus were 77.4 ± 13.2 ms and 73.2 ± 15.3 ms in retear shoulders and 66.5 ± 11.1 ms and 58.6 ± 11.7 ms in intact shoulders, respectively; the differences were significant in both muscles (P < .001). Cutoff values for prediction of retear were 71.8 ms in supraspinatus and 63.1 ms in infraspinatus. There were no significant differences in the preoperative Goutallier stages of supraspinatus and infraspinatus between the 2 groups. CONCLUSIONS: Retear shoulders demonstrated significantly higher preoperative T2 values than intact shoulders. T2 mapping can be a useful tool for predicting postoperative retears.

[Mechanism of Calculus Bovis Sativus in inhibiting hepatocyte lipid deposition based on serum pharmacology].

The aim of this paper was to investigate the molecular mechanism of Calculus Bovis Sativus( CBS) in alleviating lipid accumulation in vitro by serum pharmacology. The CBS-containing serum of mice was obtained by serum pharmacology method to evaluate its effect on the proliferation of LO2 hepatocytes. The lipid reducing effects of CBS-containing serum through Nrf2 was evaluated by fructose-induced LO2 hepatocyte steatosis model,nuclear factor erythroid 2 related factor 2( Nrf2) agonist oltipraz combined intervention,cell oil red O staining and intracellular triglyceride( TG) content. The effects of CBS-containing serum on lipid peroxidation and hepatocytes apoptosis were evaluated by reactive oxygen species( ROS) and apoptosis assay,respectively. Real-time quantitative polymerase chain reaction( PCR) was used to detect the relative expression of lipid synthesis-related genes and apoptosis-related genes.RESULTS:: showed that CBS drug-containing serum had no significant effect on LO2 hepatocyte proliferation. As compared with the model group,CBS-containing serum could effectively reduce the formation of lipid droplets in fructose-induced LO2 hepatocytes,significantly reduce intracellular TG and ROS levels,and significantly reduce hepatocyte apoptosis rate( P < 0. 05). As compared with the model group,carbohydrate responsive element binding protein( ChREBP),sterol regulatory element binding protein-1 c( SREBP-1 c),fatty acid synthase( FAS),acetyl-CoA carboxylase 1( ACC1),stearoyl-CoA desaturase 1( SCD1),Bax and caspase-3 mRNA levels were significantly reduced in CBS drug-containing serum treatment group( P<0. 05). All of the above effects could be reversed by oltipraz.In conclusion,CBS-containing serum can significantly inhibit the fructose-induced LO2 liver fat deposition,and the mechanism may be related to reducing intracellular ROS level through the Nrf2 pathway and improving intracellular peroxidation state to reduce apoptosis.

[Fatty degeneration of upper tarsal muscle as etiological factor of acquired upper eyelid ptosis]. / Zhirovaia distrofiia verkhnei tarzal'noi myshtsy kak étiologicheskii faktor priobretennogo ptoza verkhnego veka.

PURPOSE: To study the histological structure of the upper tarsal muscle (Müller's muscle of the upper eyelid) in patients with acquired ptosis and to confirm the presence of its fatty degeneration as an understudied etiological factor of upper eyelid ptosis. MATERIAL AND METHODS: A retrospective analysis was performed covering 79 biopsy samples of Müller's muscle of the upper eyelid obtained intraoperatively. Histological examination was performed with samples prepared by waxing. Planning the surgery included determination of basic parameters and the 'transparency' symptom; the Müller's muscle projection area was examined in the inverted upper eyelid, and ultrasound biomicroscopy (UBM) of the upper eyelid structures was performed. RESULTS: Among the study subjects, a group of 11 patients with isolated fatty infiltration of the upper tarsal muscle was identified. At the preoperative stage, in the group of patients with upper eyelid eversion, visibly thickened Müller's muscle advancing on the tarsus could be observed, as well as negative 'transparency' symptom; UBM showed thickened 'conjunctiva - Müller's muscle' complex, and a large number of hypoechogenic inclusions in the muscle in comparison with the intact eye. The removed muscle was thickened, yellow, with increased density and rigidity. Microsection of the histological preparations revealed fat cells located among bundles of smooth muscle fibers of the upper tarsal muscle and dispersion of smooth myocytes on the background of fat infiltration. CONCLUSION: The presence of dystrophic changes in the upper tarsal muscle is proved with clinical, macromorphological and pathohistological methods; they can be one of the independent causes of acquired upper eyelid ptosis.