Research Progress of Camptocormia in Parkinson Disease.

Camptocormia, also known as bent spine syndrome, primarily affects individuals with Parkinson disease (PD). This review provides an overview of camptocormia in PD, covering its definition, epidemiology, causes, diagnosis, and treatment. In the epidemiology section, we delve into its prevalence, gender disparities, and ongoing genetic research. Regarding diagnosis and assessment, we discuss evolving diagnostic criteria and measurement techniques, as well as new diagnostic tools. For management and treatment, a wide array of options is available, from conservative methods such as physical therapy and botulinum toxin injections to surgical interventions such as spinal orthopedic surgery and deep brain stimulation. We stress the significance of personalized care and multidisciplinary collaboration. This comprehensive review aims to provide clinicians, researchers, and healthcare professionals with a comprehensive understanding of camptocormia in PD, highlighting its clinical features, diagnostic strategies, management approaches, and future perspectives.

Osteoporosis screening using QCT-based cutoff value of Hounsfield units in patients with degenerative lumbar diseases.

PURPOSE: In patients with degenerative lumbar diseases, we aimed to establish the cutoff value of Hounsfield units (HU) for osteoporosis screening on the basis of the relationship between computed tomography (CT) HU value and volume bone mineral density (BMD) measured by quantitative computed tomography (QCT). METHODS: A total of 136 patients aged ≥ 50 years with degenerative lumbar diseases were retrospectively included. Their QCT-BMD of L1-2 were recorded, and the CT values of L1-2 were measured with the same CT images of QCT. The degree of bone loss was evaluated with the criteria based on QCT-BMD: cutoff value of 80 mg/cm3 for osteoporosis and cutoff value of 120 mg/cm3 for osteopenia. The cutoff of CT value was acquired according to the linear regression equation between CT value and QCT-BMD. RESULTS: The rate of osteoporosis, osteopenia, normal BMD was 33.8% (46/136), 51.5% (70/136), and 14.7% (20/136), respectively. The Pearson correlation coefficients between CT value and QCT-BMD were over 0.9 (P < 0.05). The cutoff of average CT value of L1-2 was calculated and adjusted to 110HU for osteoporosis and 160HU for osteopenia according the equation: average QCT-BMD of L1-2 = 0.76 âœ• average CT value of L1-2-0.46 (R2 = 0.931, P < 0.001). Cutoff value of 110HU was 91.2% (42/46) sensitive and 88.9% (80/90) specific for identifying osteoporosis. The cutoff value of 160HU was 95.0% (19/20) sensitive and 96.6% (112/116) specific for distinguishing normal BMD from abnormal BMD (osteoporosis and osteopenia). CONCLUSION: The CT value is effective in osteoporosis screening, and the QCT-based cutoff value is 110 HU for osteoporosis and 160 HU for osteopenia in the patients with degenerative lumbar disease.

Evaluating the Status and Promising Potential of Robotic Spinal Surgery Systems.

The increasing frequency of cervical and lumbar spine disorders, driven by aging and evolving lifestyles, has led to a rise in spinal surgeries using pedicle screws. Robotic spinal surgery systems have emerged as a promising innovation, offering enhanced accuracy in screw placement and improved surgical outcomes. We focused on literature of this field from the past 5 years, and a comprehensive literature search was performed using PubMed and Google Scholar. Robotic spinal surgery systems have significantly impacted spinal procedures by improving pedicle screw placement accuracy and supporting various techniques. These systems facilitate personalized, minimally invasive, and low-radiation interventions, leading to greater precision, reduced patient risk, and decreased radiation exposure. Despite advantages, challenges such as high costs and a steep learning curve remain. Ongoing advancements are expected to further enhance these systems' role in spinal surgery.

A machine learning based quantification system for automated diagnosis of lumbar spondylolisthesis on spinal X-rays.

The automated diagnosis of lumbar spondylolisthesis lacks standardized criteria and the diagnostic of lumbar spondylolisthesis itself inherently relies on the subjective judgment of experts, resulting in a lack of standardized criteria. The objective of this study is to develop a novel, fully automated diagnostic system for lumbar spondylolisthesis. A two-stage system was developed, consisting of a Mask R-CNN with Prime Sample Attention (PISA) for vertebral segmentation in the first stage and a Light Gradient Boosting Machine (LGBM) for spondylolisthesis diagnosis in the second stage. The training data was developed by a total of 936 X-ray images including neutral, extension, and flexion lateral radiographs retrospectively gathered from 312 patients diagnosed with lumbar spondylolisthesis between January 2021 and March 2022. From a model perspective, there were a total of 4680 vertebrae, of which 1056 (22.6 %) were spondylolisthesis and the rest were normal. The Bbox mAP50, Bbox mAP75, Segm mAP50, and Segm mAP75 of Mask R-CNN with PISA were 0.9852, 0.9179, 0.9741, and 0.8957, respectively. The Accuracy, AUC, Recall, Precision, and F1-score of LGBM were 0.9660, 0.9843, 0.9020, 0.9020, and 0.9020, respectively. This study presents a robust system for the diagnosis of lumbar spondylolisthesis, providing accurate detection, classification, and localization of lumbar spondylolisthesis.

Protective Effects of Vitamin D on Proteoglycans of Human Articular Chondrocytes through TGF-ß1 Signaling.

The extracellular matrix of cartilage primarily constitutes of collagen and aggrecan. Cartilage degradation starts with aggrecan loss in osteoarthritis (OA). Vitamin D (VD) plays an essential role in several inflammation-related diseases and can protect the collagen in cartilage during OA. The present study focused on the role of VD in aggrecan turnover of human articular chondrocytes treated with tumor necrosis factor α (TNF-α) and the possible mechanism. Treatment with different doses of VD and different periods of intervention with TNF-α and TGF-ß1 receptor (TGFßR1) inhibitor SB525334 were investigated. The viability of human chondrocytes and extracellular secretion of TGF-ß1 were measured. The expression of intracellular TGFßR1 and VD receptor was examined. Transcriptional and translational levels of aggrecan and the related metabolic factors were analyzed. The results showed that TNF-α markedly reduced the viability, TGFßR1 expressions and aggrecan levels of human chondrocytes, and increased disintegrin and metalloproteinase with thrombospondin motifs. The alterations were partially inhibited by VD treatment. Furthermore, the effects of VD were blocked by the TGFßR1 inhibitor SB525334 in TNF-α-treated cells. VD may prevent proteoglycan loss due to TNF-α via TGF-ß1 signaling in human chondrocytes.

Inherited genetic predisposition and imaging concordance in degenerative lumbar scoliosis patients and their descendants.

BACKGROUND: Offspring consistently exhibit similar imaging features as their parents in cases of degenerative lumbar scoliosis (DLS). Nevertheless, the role of genetic factors in the pathogenesis of DLS remains uncertain. METHODS: A prospective analysis was conducted on 35 patients with DLS and their 36 offspring. Genomic DNA was extracted from 71 blood samples for gene mutation analysis using whole exome sequencin. Various demographic and imaging parameters were compared. RESULTS: In 11 pedigrees of the 35 family members with DLS, 13 suspected pathogenic genes were identified. Among the 35 DLS patients, 11/35(31.5%) exhibited susceptibility gene mutations (mutant group), while 24/35(68.5%) had no pathogenic gene mutations (non-mutant group). AVR was more severe in mutant group than that in no-mutant group (p < 0.05). Among the 36 offspring, 11/36(30.6%) cohorts presented susceptibility genes (mutant group), 25/36(69.4%) cohorts presented no pathogenic genes (no-mutant group). More cohorts in the mutant group presented vertebral rotation (72.8%) and scoliosis (45.5%) than those (24%), (12%) in the no-mutant group, respectively (p < 0.05). Among the 36 offspring, 8/36(22.2%) presented scoliosis (study group), they all presented the same scoliosis orientation and apex vertebrae/disc location to their parents, the other 28/36(77.8%) cohorts without scoliosis were enrolled as control group, the mutation rate (62.5%) was higher in study group than that (21.4%) in control group. CONCLUSIONS: Genetic influences are significant in the onset of DLS, with affected families showing similar scoliosis patterns and identical apex vertebrae. Moreover, individuals with genetic mutations tend to have more pronounced vertebral rotation and at a higher risk of developing scoliosis.

Stiffness-related disability following long segmental posterior instrumentation and fusion: is it influenced by postoperative spinopelvic alignment?

PURPOSE: The aims of this study were to investigate the correlations between Chinese version of Lumbar Stiffness Disability Index (C-LSDI) and other clinical outcomes, and to identify the factors independently affecting stiffness-related disability after long-segment fusion in patients with degenerative lumbar scoliosis (DLS). METHODS: We performed a retrospective study of 118 consecutive surgically treated DLS cases at a single institute. Pre- and post-operative radiological parameters and postoperative health related quality of life (HRQOL) were examined to determine their correlation coefficients with postoperative C-LSDI. Patients were divided into two groups by the medium number of postoperative C-LSDI: low-stiffness group (C-LSDI < 48 points) and high-stiffness group (C-LSDI ≥ 48 points). Subsequently, differences between the two groups were assessed, and the presumed factors affecting C-LSDI evaluation were further analyzed. RESULTS: Coronal parameters and global sagittal parameters showed significant correlations with postoperative C-LSDI. The correlation coefficients between C-LSDI and Oswestry Disability Index (ODI), Japanese Orthopedic Association-29 (JOA-29), the Scoliosis Research Society-22 questionnaire (SRS-22) Function, and the Short Form-36 Health Survey (SF-36) Physical Component Scores were over 0.5. In multiple linear regression, postoperative sagittal vertical axis (ß = 0.084, p = 0.025), fusion levels (ß = 2.13, p = 0.012), and body mass index (ß = 0.867, p = 0.022) were independent related factors for C-LSDI. CONCLUSION: This study showed that all HRQOLs demonstrated the varying degree of correlations with C-LSDI, of which the ODI, JOA-29, SRS-22 Function, and SF-36 PCS were most relevant, with moderate strength of associations.Moreover, longer fusion levels, higher BMI, and greater postoperative SVA independently affect C-LSDI after long segmental posterior instrumentation and fusion for DLS.

Posterior Thoracic Antidisplacement and Fusion Surgery for a Special Type of Ossification of the Posterior Longitudinal Ligament in the Thoracic Spine: Indications and Preliminary Clinical Results of 2-Year Follow-Up.

OBJECTIVE: To describe a novel technique, posterior thoracic antidisplacement and fusion (PTAF), for a special type of ossification of the posterior longitudinal ligament in the thoracic spine (T-OPLL), and to evaluate its safety and efficacy. METHODS: From July to December 2020, 5 consecutive patients with beak-type T-OPLL located at the thoracic vertebral body level underwent PTAF surgery. Their demographic data, radiological parameters, perioperative complications, and surgery-related findings were recorded and analyzed. The surgical outcomes were assessed using a modified Japanese Orthopedic Association scale, and the recovery rate was calculated using the Hirabayashi's method. RESULTS: All patients were followed up for at least two years. The mean thickness of OPLL was 9.4 ± 1.0 mm, and the OPLL spinal canal occupying ratio was 67.7% ± 8.5%. Postoperatively, the mean antidisplacement distance of OPLL was 8.1 ± 1.8 mm, and the average shortened distance of the spinal column was 6.0 ± 1.13 mm. The mean operation time and blood loss were 158.2 ± 26.3 minutes and 460 ± 89.4 mL, respectively. Perioperative complications were cerebrospinal fluid leakage and instrument failure, 2 cases each. The mean modified Japanese Orthopedic Association score was increased from 3.6 ± 2.9 before surgery to 9.4 ± 3.0 at the last follow-up, and the average recovery rate was 84.2 ± 30.5%. CONCLUSIONS: The preliminary clinical outcomes indicate that PTAF is a safe and effective method for the treatment of beak-type T-OPLL, which has its apex located at the vertebral body level and has a high spinal canal occupation ratio.

Evaluation of the effectiveness of the femoro-sacral posterior angle system for measuring spino-pelvic morphology in high-dysplastic developmental spondylolisthesis.

OBJECTIVE: The Femoro-Sacral Posterior Angle (FSPA) system and the pelvic incidence (PI) system are utilized for measuring sagittal spino-pelvic morphology in patients with high-dysplastic developmental spondylolisthesis (HDDS). This study aimed to analyze the accuracy and stability of these two systems. METHODS: A retrospective analysis was conducted on 45 patients diagnosed with HDDS who underwent surgical treatment at our hospital (HDDS group), along with 45 patients without spondylolisthesis (normal group). Three orthopedic surgeons utilized the FSPA and PI systems to measure various parameters, including FSPA, pelvic angle(PA), sacral incidence (SI), PI, pelvic tilt (PT), and sacral slope (SS), respectively. The intraclass correlation coefficient (ICC) was employed to assess the inter-observer consistency of measurements. RESULTS: There was significant differences in all the parameters between the normal and HDDS groups (p < 0.05), except for SS (p = 0.508). Specifically, SI was lower in HDDS group than in the normal group (23.0 ± 13.4 vs. 38.6 ± 7.1), whereas SS was higher (35.3 ± 15.7 vs. 33.6 ± 7.4). Within HDDS group, there was no statistically significant difference in PI (p = 0.159), SS (p = 0.319), and FSPA (p = 0.173) between pre- and post-surgery measurements. The ICC results indicated superior reliability for the FSPA system (0.842-0.885) compared to the PI system (0.682-0.720) within the HDDS group. CONCLUSION: Compared with the PI system, the FSPA system demonstrated higher accuracy in evaluating spino-pelvic morphology in HDDS patients. Moreover, it exhibited higher ICC values, indicating higher inter-observer reliability, thus serving as an effective method for assessing spino-pelvic morphology in HDDS patients.

Searching for the optimal precondition procedure for mesenchymal stem/stromal cell treatment: Facts and perspectives.

Mesenchymal stem/stromal cells are potential optimal cell sources for stem cell therapies, and pretreatment has proven to enhance cell vitality and function. In a recent publication, Li et al explored a new combination of pretreatment conditions. Here, we present an editorial to comment on their work and provide our view on mesenchymal stem/stromal cell precondition.

Biomechanical analysis of spinal cord injury during scoliosis correction surgery.

Introduction: Surgical correction is a common treatment for severe scoliosis. Due to the significant spinal deformation that occurs with this condition, spinal cord injuries during corrective surgery can occur, sometimes leading to paralysis. Methods: Such events are associated with biomechanical changes in the spinal cord during surgery, however, their underlying mechanisms are not well understood. Six patient-specific cases of scoliosis either with or without spinal complications were examined. Finite element analyses (FEA) were performed to assess the dynamic changes and stress distribution of spinal cords after surgical correction. The FEA method is a numerical technique that simplifies problem solving by replacing complex problem solving with simplified numerical computations. Results: In four patients with poor prognosis, there was a concentration of stress in the spinal cord. The predicted spinal cord injury areas in this study were consistent with the clinical manifestations of the patients. In two patients with good prognosis, the stress distribution in the spinal cord models was uniform, and they showed no abnormal clinical manifestations postoperatively. Discussion: This study identified a potential biomechanical mechanism of spinal cord injury caused by surgical correction of scoliosis. Numerical prediction of postoperative spinal cord stress distribution might improve surgical planning and avoid complications.

Impact of postoperative spinal malalignment on postoperative health-related quality of life after long-level fixation for degenerative lumbar scoliosis: does residual coronal angularity matter?

PURPOSE: This study evaluates the influence of spinal malalignment on health-related quality of life (HRQOL) in a long-level fusion spine. METHODS: This was a retrospective analysis of 121 consecutive patients with DLS after long-segment fusion. HRQOL and radiographic parameters were collected at final follow-up. For postoperative residual Cobb angle (CA), patients were divided as follows: group (0) (CA < 10°), group (+) (CA 10°âˆ¼20 °), and group (++) (CA > 20°). For postoperative coronal vertical axis (CVA), patients were separated as follows: group (0) (CVA < 2 cm), group (+) (CVA 2 ∼ 3 cm), and group (++) (CVA > 3 cm). Patients were also grouped by the sagittal modifiers as group (0), group (+), and group (++) according to the Scoliosis Research Society (SRS)-Schwab classification, respectively. RESULTS: Visual analog scale (VAS) for back was significantly lower in CA 10°âˆ¼20° group compared to other groups. Patients with remnant CA > 20° showed worse Oswestry Disability Index (ODI), SRS-22 and the 36-item Short Form Health Survey (SF-36) - physical component scores (PCS). Sagittal vertical axis (SVA) showed significant correlation with HRQOLs after surgery, and the statistical significance of ODI, SRS-22 and SF-36 scores was observed among subgroups. CONCLUSIONS: In long-level fused spine, residual CA > 20° resulted in worse clinical outcomes and was recommended to avoid during surgery. And 10° to 20° residual CA was acceptable in DLS patients and even better than Cobb angle < 10° in several HRQOLs, therefore strictly pursing upright alignment seems unnecessary. SVA also showed effectiveness in assessing HRQOL in the fixed spine.

Revealing the novel metabolism-related genes in the ossification of the ligamentum flavum based on whole transcriptomic data.

Backgrounds: The ossification of the ligamentum flavum (OLF) is one of the major causes of thoracic myelopathy. Previous studies indicated there might be a potential link between metabolic disorder and pathogenesis of OLF. The aim of this study was to determine the potential role of metabolic disorder in the pathogenesis of OLF using the strict bioinformatic workflow for metabolism-related genes and experimental validation. Methods: A series of bioinformatic approaches based on metabolism-related genes were conducted to compare the metabolism score between OLF tissues and normal ligamentum flavum (LF) tissues using the single sample gene set enrichment analysis. The OLF-related and metabolism-related differentially expressed genes (OMDEGs) were screened out, and the biological functions of OMDEGs were explored, including the Gene Ontology enrichment analysis, Kyoto Encyclopedia of Genes and Genomes enrichment analysis, and protein-protein interaction. The competing endogenous RNA (ceRNA) network based on pairs of miRNA-hub OMDEGs was constructed. The correlation analysis was conducted to explore the potential relationship between metabolic disorder and immunity abnormality in OLF. In the end, the cell experiments were performed to validate the roles of GBE1 and TNF-α in the osteogenic differentiation of LF cells. Results: There was a significant difference of metabolism score between OLF tissues and normal LF tissues. Forty-nine OMDEGs were screened out and their biological functions were determined. The ceRNA network containing three hub OMDEGs and five differentially expressed miRNAs (DEmiRNAs) was built. The correlation analysis between hub OMDEGs and OLF-related infiltrating immune cells indicated that metabolic disorder might contribute to the OLF via altering the local immune status of LF tissues. The cell experiments determined the important roles of GBE1 expression and TNF-α in the osteogenic differentiation of LF cells. Conclusions: This research, for the first time, preliminarily illustrated the vital role of metabolic disorder in the pathogenesis of OLF using strict bioinformatic algorithms and experimental validation for metabolism-related genes, which could provide new insights for investigating disease mechanism and screening effective therapeutic targets of OLF in the future.

[Radiographic parameters and influencing factors of paraspinal muscle degeneration in healthy people].

Objective: To measure the paraspinal muscle parameters, explore the characteristics of paraspinal muscles, and investigate the influence factors of paraspinal muscle degeneration in healthy people. Methods: Eighty-two healthy Chinese people were prospectively recruited between February 2020 and November 2020, including 36 males and 46 females. The age ranged from 21 to 75 years, with a mean of 48.0 years. The height ranged from 150 to 183 cm, with a mean of 165.6 cm. The body mass ranged from 43 to 100 kg, with a mean of 65.4 kg. The body mass index (BMI) ranged from 16.7 to 32.4 kg/m 2, with a mean of 23.7 kg/m 2. Parameters of the paraspinal muscles (multifidus muscle, erector spinae muscle, and psoas major muscle) at L 3, L 4, and L 5 levels were measured by MRI, including the relative total cross-sectional area (rtCSA), relative fatty cross-sectional area (rfCSA), relative signal intensity (rSI), and fatty infiltration (FI). The differences of paraspinal muscle parameters at different genders and different measurement levels were compared; Pearson or Spearman correlation analysis was used to explore the relationship between paraspinal muscle parameters and age, height, body mass, BMI. Results: From L 3 to L 5 level, the rtCSA and rfCSA of multifidus muscle and psoas major muscle as well as the rfCSA of erector spinae muscle increased, while rtCSA of erector spinae muscle decreased. The FI and rSI of paraspinal muscles increased gradually. The parameters of paraspinal muscles at L 4 and L 5 levels were significantly different from those at L 3 levels ( P<0.05). There were significant differences in rtCSA and rfCSA of multifidus muscle, rtCSA, FI, and rSI of erector spinae muscle as well as rtCSA, rfCSA, and FI of psoas major muscle between L 4 and L 5 levels ( P<0.05). Compared with males, the rfCSA and FI of multifidus muscle, FI of erector spinae muscle, and FI of psoas major muscle were significantly higher in females, while the rtCSA of psoas major muscle was significantly lower ( P<0.05). Age was significantly negatively correlated with rtCSA of paraspinal muscles ( P<0.05), but significantly positively correlated with FI of paraspinal muscles, rfCSA and rSI of multifidus and erector spinae muscles ( P<0.05). Height was significantly negatively correlated with rfCSA and FI of paraspinal muscles ( P<0.05). Conclusion: The degree of paraspinal muscle degeneration increases gradually along the spine axis from head to tail. Paraspinal muscle degeneration is related to age, height, and gender. The relationship between the body mass, BMI and paraspinal muscle degeneration needs further study.

Patient-specific 3D-printed Brace for Adolescent Idiopathic Scoliosis: A Prospective Cohort Study.

OBJECTIVE: To evaluate the efficacy and safety of patient-tailored 3D printed brace in the treatment of adolescent idiopathic scoliosis (AIS), and to compare the health-related quality of life (HRQoL) of patients treated with 2 different types of brace. MATERIALS AND METHODS: From September 2017 to August 2020, 103 AIS patients requiring non-operative management were prospectively recruited in this study. All patients were followed up every 6 months, clinical and radiologic examination were assessed at each follow-up time. Full-length anteroposterior radiographs of the spine in the standing position were obtained. At the last follow-up, each patient completed a standardized HRQoL questionnaire. Compliance is defined as that the patient insists on wearing the brace for ≥23 hours every day (full-time wearing) and follow-up every 6 months until bone maturity. The rate of major curve Cobb progression was defined that maximum Cobb angle of major curve greater than 6° compared with that at the initial diagnosis, or aggravated to more than 45° so that orthopedic surgery was recommended during treatment, which was defined as the rate of conversion to surgery. The effects of these 2 types of braces on the rate of major curve Cobb progression and HRQoL were analyzed by independent sample t test and χ2 test. RESULTS: The thickness was 4 mm for thoracolumbosacral orthosis (TLSO) and 3 mm for 3D-printed brace (3DPB). In addition, compared with the material used in TLSO, the weight (600-800 g) of the 3DPB materials with the same area is reduced by about 25% to 30%. In our sample, 55 patients (49.1%) and 48 patients (33.1%) were respectively included in the 3DPB cohort and the TLSO cohort. The maximum Cobb angle of major curve in the 3DPB cohort was significantly lower than those in the TLSO cohort at 6 months, 12 months, and the last follow-up (P < 0.01). The thoracic kyphosis (TK) and lumbar lordosis (LL) of the 2 cohorts at the last follow-up were lower than those before brace treatment, in addition, there was a significant difference in TK (P = 0.001) and LL (P = 0.004) between the 2 cohorts at the follow-up. The scores of physical function, pain, self-image, mental health, and treatment satisfaction in the Chinese version of the 22-item questionnaire of the Scoliosis Research Society in the 3DPB cohort were higher than those in the TLSO cohort (P < 0.01 and P < 0.05, respectively). The scores of the 3DPB cohort were significantly higher than those of the TLSO group in the 4 dimensions (P = 0.008, 0.013, 0.015, and 0.002, respectively) of the EuroQol-5D health description system except for mobility, and the overall health status of EuroQol-5D was higher for the 3DPB cohort (P < 0.001). At the last follow-up, 1 patient in the 3DPB cohort and 10 patients in the TLSO cohort had major curve Cobb progression of greater than 6°, and the rate of major curve Cobb progression in the 3DPB cohort was significantly lower than that in the TLSO cohort (OR 14.2, 95% CI 1.7∼115.8, P < 0.01). One patient in the 3DPB and 7 patients in the TLSO cohorts received subsequent surgery or were recommended for surgery, and the rate of conversion to surgery was significantly lower than in the 3DPB cohort (OR 9.2, 95% CI 1.1∼77.9, P < 0.05). CONCLUSIONS: A patient-tailored 3D-printed brace is lighter, thinner, and more comfortable than conventional braces in the treatment of AIS. It can substantially improve the HRQoL of patients and can significantly reduce the progression of major curve Cobb progression and rate of conversion of surgery.

An overview of magnesium-based implants in orthopaedics and a prospect of its application in spine fusion.

Due to matching biomechanical properties and significant biological activity, Mg-based implants present great potential in orthopedic applications. In recent years, the biocompatibility and therapeutic effect of magnesium-based implants have been widely investigated in trauma repair. In contrast, the R&D work of Mg-based implants in spinal fusion is still limited. This review firstly introduced the general background for Mg-based implants. Secondly, the mechanical properties and degradation behaviors of Mg and its traditional and novel alloys were reviewed. Then, different surface modification techniques of Mg-based implants were described. Thirdly, this review comprehensively summarized the biological pathways of Mg degradation to promote bone formation in neuro-musculoskeletal circuit, angiogenesis with H-type vessel formation, osteogenesis with osteoblasts activation and chondrocyte ossification as an integrated system. Fourthly, this review followed the translation process of Mg-based implants via updating the preclinical studies in fracture fixation, sports trauma repair and reconstruction, and bone distraction for large bone defect. Furthermore, the pilot clinical studies were involved to demonstrate the reliable clinical safety and satisfactory bioactive effects of Mg-based implants in bone formation. Finally, this review introduced the background of spine fusion surgeryand the challenges of biological matching cage development. At last, this review prospected the translation potential of a hybrid Mg-PEEK spine fusion cage design.

Modified pedicle subtraction osteotomy for osteoporotic vertebral compression fractures: a retrospective study of 104 patients.

BACKGROUND: Osteoporotic vertebral compression fractures (OVCF) caused by osteoporosis is a common clinical fracture type. There are many surgical treatment options for OVCF, but there is a lack of comparison among different options. Therefore, we counted a total of 104 cases of OVCF operations with different surgical plans, followed up the patients, and compared the surgical outcome indications before, after and during the follow-up. METHOD: 104 patients who underwent posterior osteotomy (Modified PSO, SPO, PSO, VCR) and kyphosis correction surgery at our hospital between April 2006 and August 2021 with a minimum follow-up period of 24 months were included. All cases were injuries induced by a fall incurred while standing or lifting heavy objects without high-energy trauma. The mean CT value was 71 HU, which was below 110 HU, indicating severe osteoporosis. The indications for surgery included gait disturbance due to severe pain with pseudarthrosis, increased kyphotic angle, and progressive neurological symptoms. Pre- and postoperative CL, TLK, TK, PrTK, TKmax, GK, LL, PI, SS, PT, SVA, TPA, were investigated radiologically. Additionally, We evaluated estimated blood loss, surgical time and perioperative symptom. RESULT: The results show, after operation, TLK (37.32 ± 10.61° vs. 11.01 ± 8.06°, P < 0.001), TK (35.42 ± 17.64° vs. 25.62 ± 12.24°, P < 0.001), TKmax (49.71 ± 16.32° vs. 24.12 ± 13.34°, P < 0.001), SVA (44.91 ± 48.67 vs. 23.52 ± 30.21, P = 0.013), CL (20.23 ± 13.21° vs. 11.45 ± 9.85°, P = 0.024) and TPA (27.44 ± 12.76° vs. 13.91 ± 9.24°, P = 0.009) were improved significantly in modified Pedicle subtraction osteotomy (mPSO) after operation. During follow-up, TLK (37.32 ± 10.61° vs. 13.88 ± 10.02°, P < 0.001) and TKmax (49.71 ± 16.32° vs. 24.12 ± 13.34°, P < 0.001) were improved significantly in Modified PSO group. In additon, estimated blood loss (790.0 ± 552.2 ml vs. 987.0 ± 638.5 ml, P = 0.038), time of operation (244.1 ± 63.0 min vs. 292.4 ± 87.6 min, P = 0.025) were favorable in Modified PSO group compared to control group. CONCLUSION: To conclude, mPSO could acquire a favorable degree of kyphosis correction as well as fewer follow-up complications. Compared with other surgical methods, it also has the advantages of less surgical trauma and shorter operation time. It can be an effective solution for the treatment of OVCF.

Paraspinal muscle endurance and morphology (PMEM) score: a new method for prediction of postoperative mechanical complications after lumbar fusion.

BACKGROUND CONTEXT: Although the relationships between paraspinal muscles and lumbar degenerative disorders have been acknowledged, paraspinal muscle evaluation has not been incorporated into clinical therapies. PURPOSE: We aimed to establish a novel paraspinal muscle endurance and morphology (PMEM) score to better predict mechanical complications after lumbar fusion. STUDY DESIGN: Prospective cohort study. PATIENT SAMPLE: A total of 212 patients undergoing posterior lumbar interbody fusion with at least 1 year of follow-up were finally included. OUTCOME MEASURES: Mechanical complications including screw loosening, pseudarthrosis and other complications like cage subsidence, and patient-reported outcomes were evaluated at last follow-up. METHODS: The PMEM score comprised 1 functional muscular parameter (the performance time of the endurance test) and 2 imaging muscular parameters (relative functional cross-sectional area [rFCSA] of paraspinal extensor muscles [PEM] and psoas major [PS] on magnetic resonance imaging). The score was established based on a weighted scoring system created by rounding ß regression coefficients to the nearest integer in univariate logistic regression. The diagnostic performance of the PMEM score was determined by binary logistic regression model and receiver operating characteristic (ROC) curve with the area under the curve (AUC). Additionally, pairwise comparisons of ROC curves were conducted to compare the diagnostic performance of the PMEM score with conventional methods based on a single muscular parameter. Moreover, differences of mechanical complications and patient-reported outcomes among the PMEM categories were analyzed using Chi-square test with Bonferroni correction. RESULTS: The PMEM score, calculated by adding the scores for each parameter, ranges from 0 to 5 points. Patients with higher PMEM scores exhibited higher rates of mechanical complications (p<.001). Binary logistic regression revealed that the PMEM score was an independent factor of mechanical complications (p<.001, OR=2.002). Moreover, the AUC of the PMEM score (AUC=0.756) was significantly greater than those of the conventional methods including the endurance test (AUC=0.691, Z=2.036, p<.05), PEM rFCSA (AUC=.690, Z=2.016, p<.05) and PS rFCSA (AUC=0.640, Z=2.771, p<.01). In terms of the PMEM categories, a score of 0-1 was categorized as low-risk muscular state of mechanical complications; 2-3, as moderate; and 4-5, as high-risk state. Moving from the low-risk state to the high-risk state, there was a progressive increase in the rates of mechanical complications (13.8% vs 32.1% vs 72.7%; p<.001), and a decrease in the rates of clinically significant improvement of patient-reported outcomes (all p<.05). CONCLUSIONS: The PMEM score might comprehensively evaluate paraspinal muscle degeneration and exhibit greater ability in predicting mechanical complications than the conventional evaluations after lumbar fusion. Surgeons might develop individualized treatment strategy tailored to different muscle degeneration statuses reflected by the PMEM score for decreasing the risk of mechanical complications.

Preoperative and follow-up variations of psoas major muscle are related to S1 screw loosening in patients with degenerative lumbar spinal stenosis.

BACKGROUND: It was reported the paraspinal muscle played an important role in spinal stability. The preoperative paraspinal muscle was related to S1 screw loosening. But the relationship between preoperative and postoperative change of psoas major muscle (PS) and S1 pedicle screw loosening in degenerative lumbar spinal stenosis (DLSS) patients has not been reported. This study investigated the effects of preoperative and follow-up variations in the psoas major muscle (PS) on the first sacral vertebra (S1) screw loosening in patients with DLSS. METHODS: 212 patients with DLSS who underwent lumbar surgery were included. The patients were divided into the S1 screw loosening group and the S1 screw non-loosening group. Muscle parameters were measured preoperatively and at last follow-up magnetic resonance imaging. A logistic regression analysis was performed to investigate the risk factors for S1 screw loosening. RESULTS: The S1 screw loosening rate was 36.32% (77/212). The relative total cross-sectional areas and relative functional cross-sectional areas (rfCSAs) of the PS at L2-S1 were significantly higher after surgery. The increased rfCSA values of the PS at L3-S1 in the S1 screw non-loosening group were significantly higher than those in the S1 screw loosening group. The regression analysis showed male, lower CT value of L1 and longer segment fusion were independent risk factors for S1 screw loosening, and postoperative hypertrophy of the PS was a protective factor for S1 screw loosening. CONCLUSIONS: Compared to the preoperative muscle, the PS size increased and fatty infiltration decreased after surgery from L2-3 to L5-S1 in patients with DLSS after short-segment lumbar fusion surgery. Postoperative hypertrophy of the PS might be considered as a protective factor for S1 screw loosening. MRI morphometric parameters and postoperative selected exercise of PS for DLSS patients after posterior lumbar fusion surgery might contribute to improvement of surgical outcome.

Deep Learning Model Coupling Wearable Bioelectric and Mechanical Sensors for Refined Muscle Strength Assessment.

Muscle strength (MS) is related to our neural and muscle systems, essential for clinical diagnosis and rehabilitation evaluation. Although emerging wearable technology seems promising for MS assessment, problems still exist, including inaccuracy, spatiotemporal differences, and analyzing methods. In this study, we propose a wearable device consisting of myoelectric and strain sensors, synchronously acquiring surface electromyography and mechanical signals at the same spot during muscle activities, and then employ a deep learning model based on temporal convolutional network (TCN) + Transformer (Tcnformer), achieving accurate grading and prediction of MS. Moreover, by combining with deep clustering, named Tcnformer deep cluster (TDC), we further obtain a 25-level classification for MS assessment, refining the conventional 5 levels. Quantification and validation showcase a patient's postoperative recovery from level 3.2 to level 3.6 in the first few days after surgery. We anticipate that this system will importantly advance precise MS assessment, potentially improving relevant clinical diagnosis and rehabilitation outcomes.