Associations among Preoperative Malnutrition, Muscle Loss, and Postoperative Walking Ability in Intertrochanteric Fractures: A Retrospective Study.

Sarcopenia and malnutrition are increasing in older adults and are reported risk factors for functional impairment after hip fracture surgery. This study aimed to investigate the associations between skeletal muscle mass loss, malnutrition, and postoperative walking ability in patients with hip fracture. We retrospectively reviewed patients who underwent intertrochanteric fracture surgery at our institute. The psoas muscle index, controlling nutritional status score, and functional ambulation category (FAC) were used to evaluate skeletal muscle mass, nutritional status, and walking ability, respectively. Six months after surgery, walking ability was assessed as either "gait disturbance" or "independent gait". Multivariate binomial logistic regression analysis, with skeletal muscle mass, nutritional status, and other factors, was used to predict the risk of being assigned to the gait disturbance group. This study included 95 patients (mean age, 85.2 years; 70 women). Sixty-six patients had low skeletal muscle mass, 35 suffered from malnutrition, and 28 had both. Malnutrition and low skeletal muscle mass were significantly associated with postoperative gait disturbance (FAC < 3). Preoperative low skeletal muscle mass and malnutrition were risk factors for postoperative poor walking ability. Further preventive interventions focusing on skeletal muscle mass and nutritional status are required.

Comparison of screw versus locking plate fixation via sinus tarsi approach for displaced intra-articular calcaneal fractures.

BACKGROUND: The optimal treatment of displaced intra-articular calcaneal fractures (DIACF) is controversial. This study compared the fixation stability of screws and locking plates in DIACF treated via the sinus tarsi approach (STA). METHODS: We retrospectively evaluated 118 DIACF cases treated via STA and extracted data that could affect treatment outcomes. Loss of Böhler's angle after surgery was measured to compare fixation stability. RESULTS: The loss of Böhler's angles was significantly smaller in the locking plate group than in the screw group (2.6 ± 2.7º vs. 5.6 ± 5.3º, P < 0.01). There was no difference in the clinical outcomes between the groups. On multivariate logistic regression analysis, screw fixation was significantly associated with loss of Böhler's angle by> 10º (odds ratio, 8.63; 95% confidence interval, 1.16-64.4; P < 0.05). CONCLUSIONS: Locking plate fixation is more reliable than screw fixation for preventing correction loss in DIACF treated via STA. LEVEL OF EVIDENCE: III.

Ideal insertion point and projection of the infra-acetabular screw in acetabular fracture surgery.

BACKGROUND: In acetabular fracture surgery, an infra-acetabular screw (IAS) is inserted from the anterior to the posterior column through the infra-acetabular corridor to stabilize both columns. Although the IAS is useful for increasing fixation strength, proper placement requires proficiency and often results in extraosseous screw penetration. The complex anatomy of the infra-acetabular corridor and difficult intraoperative detection of the ideal insertion point and angle make proper placement of the IAS challenging. This study aimed to detect the ideal insertion point and angle of the IAS based on anatomical landmarks that can be directly identified intraoperatively. METHODS: We retrospectively reviewed the pelvic CT of 50 adults who underwent serial slice CT imaging. The pelvic inlet plane (PIP), which contains the anterior border of both the sacroiliac joint and posterior superior edge of the pubic symphysis, was used as the reference plane for the pelvic coordinate system to simulate the ideal insertion of IAS. The distance from the posterior superior edge of the pubic symphysis to the ideal insertion point of the IAS (IAS distance) and the angle and length of the IAS that could be inserted from the ideal insertion point were measured. RESULTS: The mean IAS distance was 61.0 ± 5.7 mm (57.6 ± 4.3 mm in men and 64.4 ± 4.9 mm in women). The mean angle between ideal IAS and yz-plane on the outlet view (α-angle) was 8.4 ± 6.6 ° (6.4 ± 5.6° in men and 10.5 ± 7.0° in women). The mean angle between ideal IAS and y-axis on the yz-plane (ß-angle) was 86.5 ± 10.6 ° (86.0 ± 10.3° in men and 87.0 ± 10.9° in women). The length of IAS was 97.1 ± 4.7 mm in men and 89.2 ± 3.6 mm in women. CONCLUSION: The IAS ideal insertion point detected as a distance from the pubic symphysis may aid in the proper insertion of the IAS during surgery. The insertion angle was parallel or tilted 10 ° laterally to the longitudinal axis in the pelvic outlet plane and almost perpendicular to the PIP in the sagittal plane when inserted from the ideal insertion point.

Comprehensive Method for Exosome Isolation and Proteome Analysis for Detection of CCN Factors in/on Exosomes.

Cellular Communication Network (CCN) proteins are secretory growth factors often associated with extracellular matrix (ECM) and extracellular vesicles (EVs) such as exosomes or matrix-coated vesicles. CCN factors and fragments loaded on/in EVs may play key roles in cell communication networks in cancer biology, bone and cartilage metabolism, wound healing, and tissue regeneration. CCN proteins and EVs/exosomes are found in body fluids, such as blood, urine, milk, and supernatants of the two-dimensionally (2D) cultured cells and three-dimensionally (3D) cultured tissues, such as spheroids or organoids. More than ten methods to isolate exosomes or EVs have been developed with different properties. Here, we introduce comprehensive protocols for polymer-based precipitation, affinity purification, ultracentrifugation methods combined with the ultrafiltration method for isolating CCN-loaded exosomes/EVs from 2D and 3D cultured tissues, and proteome analysis using mass spectrometry for comprehensive analysis of CCN proteins.

Exosome-Based Molecular Transfer Activity of Macrophage-Like Cells Involves Viability of Oral Carcinoma Cells: Size Exclusion Chromatography and Concentration Filter Method.

Extracellular vesicles (EV) heterogeneity is a crucial issue in biology and medicine. In addition, tumor-associated macrophages are key components in cancer microenvironment and immunology. We developed a combination method of size exclusion chromatography and concentration filters (SEC-CF) and aimed to characterize different EV types by their size, cargo types, and functions. A human monocytic leukemia cell line THP-1 was differentiated to CD14-positive macrophage-like cells by stimulation with PMA (phorbol 12-myristate 13-acetate) but not M1 or M2 types. Using the SEC-CF method, the following five EV types were fractionated from the culture supernatant of macrophage-like cells: (i) rare large EVs (500-3000 nm) reminiscent of apoptosomes, (ii) EVs (100-500 nm) reminiscent of microvesicles (or microparticles), (iii) EVs (80-300 nm) containing CD9-positive large exosomes (EXO-L), (iv) EVs (20-200 nm) containing unidentified vesicles/particles, and (v) EVs (10-70 nm) containing CD63/HSP90-positive small exosomes (EXO-S) and particles. For a molecular transfer assay, we developed a THP-1-based stable cell line producinga GFP-fused palmitoylation signal (palmGFP) associated with the membrane. The THP1/palmGFP cells were differentiated into macrophages producing palmGFP-contained EVs. The macrophage/palmGFP-secreted EXO-S and EXO-L efficiently transferred the palmGFP to receiver human oral carcinoma cells (HSC-3/palmTomato), as compared to other EV types. In addition, the macrophage-secreted EXO-S and EXO-L significantly reduced the cell viability (ATP content) in oral carcinoma cells. Taken together, the SEC-CF method is useful for the purification of large and small exosomes with higher molecular transfer activities, enabling efficient molecular delivery to target cells.