Biomechanical analysis of plate versus K-wire fixation for metacarpal shaft fractures with wedge-shaped bone defects.

BACKGROUND: Metacarpal shaft fracture is a common type of hand fracture. Numerous studies have explored fixing transverse fractures in the midshaft of the metacarpal bone. However, this section of the metacarpal bone is often susceptible to high-energy injury, resulting in comminuted fracture or bone loss. In such cases, wedge-shaped bone defects can develop in the metacarpal shaft, increasing the difficulty of performing fracture fixation. Notably, the research on this type of fracture fixation is limited. This study compared the abilities of four fixation methods to fix metacarpal shaft fractures with wedge-shaped bone defects. METHODS: In total, 28 artificial metacarpal bones were used. To create wedge-shaped bone defects, an electric saw was used to create metacarpal shaft fractures at the midshaft of each bone. The artificial metacarpal bones were then divided into four groups for fixation. The bones in the first group were fixed with a dorsal locked plate (DP group), those in the second group were fixed with a volar locked plate (VP group), and those in the third group were fixed by combining dorsal and volar locked plates (DP + VP group), and those in the fourth group were fixed with two K-wires (2 K group). Cantilever bending tests were conducted using a material testing machine to measure yielding force and stiffness. The four groups' fixation capabilities were then assessed through analysis of variance and Tukey's test. RESULTS: The DP + VP group (164.1±44.0 N) achieved a significantly higher yielding force relative to the 2 K group (50.7 ± 8.9 N); the DP group (13.6 ± 3.0 N) and VP group (12.3 ± 1.0 N) did not differ significantly in terms of yielding force, with both achieving lower yielding forces relative to the DP + VP group and 2 K group. The DP + VP group (19.8±6.3 N/mm) achieved the highest level of stiffness, and the other three groups did not differ significantly in terms of stiffness (2 K group, 5.4 ± 1.1 N/mm; DP group, 4.0 ± 0.9 N/mm; VP group, 3.9 ± 1.9 N/mm). CONCLUSIONS: The fixation method involving the combined use of dorsal and volar locked plates (DP + VP group) resulted in optimal outcomes with respect to fixing metacarpal shaft fractures with volar wedge bone defects.

Mathematical analysis in the design of digital artery-based V-Y advancement flap in treating proximal interphalangeal joint flexion contracture.

BACKGROUND: The digital artery-based V-Y advancement flap is a widely used flap for soft tissue coverage in the treatment of flexion contracture of the proximal interphalangeal (PIP) joint. A standard method for the flap design and a mathematical method to predict the advance distance have not been well established. In this study, we proposed a simplified method for the design of V-Y advancement flaps based on digital arteries and used a geometric model to predict the advance distance for the flexion contracture correction surgery. METHODS: According to the general concept of hand flap design and law of cosine, we proposed three principles in the design of the digital artery-based V-Y advancement flap that should be followed. Since 2021 to 2022, finger geometric data of 120 fingers (index, middle, ring, and small fingers) from 30 healthy participants were collected and analysed to evaluate the necessary advance distance and flap tip angle for PIP flexion contracture correction of different fingers by our flap design method. RESULTS: The middle finger needed a significantly longer advance distance compared to other fingers in the same degree flexion contracture correction. The ring finger had the largest length-to width ratio and smallest flap tip angle among the four fingers in the V-Y flap design. No vertical scar crossed the flexion creases and flap tip angle < 20° was found in the tentative V-Y flap design for the 120 fingers. CONCLUSIONS: Our flap design method provides a proper advance distance and flap length-to-width ratio without common skin complications in the flap design for PIP flexion contracture of index, middle, ring and small fingers. This geometric model provides a mathematical basis for prediction of advance distance and flap tip angle in the design of a digital artery-based V-Y advancement flap.

Intermittent parathyroid hormone treatment affects the bone structural parameters and mechanical strength of the femoral neck after ovariectomy-induced osteoporosis in rats.

BACKGROUND: Menopause-induced decline in estrogen levels in women is a main factor leading to osteoporosis. The objective of this study was to investigate the effect of intermittent parathyroid hormone (PTH) on bone structural parameters of the femoral neck in ovariectomized rats, in addition to correlations of maximum fracture force. METHODS: Fifteen female Wister rats were divided into three groups: (1) control group; (2) ovariectomized (OVX) group; and (3) OVX + PTH group. All rats were then killed and the femurs extracted for microcomputed tomography scanning to measure volumetric bone mineral density (vBMD) and bone structural parameters of the femoral neck. Furthermore, the fracture forces of femoral neck were measured using a material testing system. RESULTS: Compared with the control and OVX + PTH groups, the OVX group had significantly lower aBMD, bone parameter, and mechanical strength values. A comparison between OVX and OVX + PTH groups indicated that PTH treatment increased several bone parameters. However, the OVX + PTH groups did not significantly differ with the control group with respect to the bone structural parameters, except for trabecular bone thickness of cancellous bone, which was greater. In addition, among the bone structural parameters, the CSA and BSI of cortical bone were significantly correlated with the maximum fracture force of the femoral neck, with correlations of, respectively, 0.682 (p = 0.005) and 0.700 (p = 0.004). CONCLUSION: Intermittent PTH helped treat ovariectomy-induced osteoporosis of cancellous bone and cortical bone in the femoral necks of rats. The ability of the femoral neck to resist fracture was highly correlated with the two parameters, namely cross-sectional area (CSA) and bone strength index (= vBMD × CSA), of cortical bone in the femoral neck and was less correlated with aBMD or other bone structural parameters.

Midterm Results of Arthroscopy-Assisted "Tent Form" Triangular Fibrocartilage Complex Repair With Dorsal Distal Radioulnar Joint Capsule Imbrication for Posttraumatic Chronic Distal Radioulnar Joint Instability.

PURPOSE: To evaluate the outcomes of "tent form" triangular fibrocartilage complex (TFCC) repair combined with dorsal distal radioulnar joint (DRUJ) capsule imbrication for posttraumatic chronic DRUJ instability. METHODS: All patients treated with arthroscopic "tent form" TFCC repair and DRUJ capsule imbrication from 2016 to 2019 were retrospectively reviewed. The inclusion criteria were symptomatic chronic DRUJ instability for >6 months and dorsal DRUJ subluxation on magnetic resonance imaging. The Disabilities of the Arm, Shoulder, and Hand score, Patient-Rated Wrist Evaluation, grip strength, Modified Mayo Wrist Score, range of motion, and distal radioulnar joint stability were assessed for a minimum of 2 years postoperatively. RESULTS: Thirty-eight patients were included in the final analysis. The average follow-up duration was 35.6 months (range, 24-48 months). The 24-month postoperative grip strengths and 3-dimensional motions of wrist were not significantly different from that of the nonoperated wrist. Compared with their preoperative status, Disabilities of the Arm, Shoulder, and Hand score, Patient-Rated Wrist Evaluation, and Modified Mayo Wrist Score indicated the significant improvement with P values of .001, .001, and .002, respectively. CONCLUSIONS: In chronic DRUJ instability with a loosening dorsal capsule, "tent form" TFCC transcapsular repair combined with DRUJ capsule imbrication restored the integrity of TFCC and dorsal DRUJ capsule and achieved a promising outcome. We recommend this procedure as an option of treatment for patients with posttraumatic chronic DRUJ instability. LEVEL OF EVIDENCE: IV, case series.

Long-term exposure to fine particulate matter and osteoporotic fracture: A case-control study in Taiwan.

Few studies have explored the relationship between long-term exposure to particulate matter with an aerodynamic diameter of ≤2.5 µm (PM2.5) and osteoporotic fracture, particularly in high PM2.5 level areas. The aim of this study was to assess the association between long-term exposure to PM2.5 and osteoporotic fracture. We performed a matched case-control study of 16,175 participants obtained from a hospital registry during 2005-2014 in Taiwan. A major osteoporotic fracture was defined as a fracture of the spine, hip, proximal humerus, and forearm. We applied satellite-based spatiotemporal models with 1-km resolution to individually calculate the 1-year average PM2.5 concentration before the index date which was defined as the first visit date for the osteoporotic fracture. Logistic regression models with and without potential confounding factors were used to estimate odds ratios (OR) and 95% confidence intervals (CI) between PM2.5 and osteoporotic fracture, whereas a restricted cubic spline model was used to estimate the dose-response relationship. The sample's median age was 44.7 years (interquartile range: 30.7, 63.1 years). We observed that long-term PM2.5 exposure was associated with osteoporotic fracture, the OR was 1.12 (95% CI: 1.03, 1.22) per 10-µg/m3 increase in PM2.5 in women. In the dose-response association, the OR of osteoporotic fracture was significantly increased for PM2.5 exposures more than 41 µg/m3. We did not find a significant association between PM2.5 (per 10-µg/m3 increase) and osteoporotic fracture among overall population (adjusted OR, 1.02 [95% CI, 0.97 to 1.08]) and men (adjusted OR, 0.94 [95% CI, 0.86 to 1.02]). The results of the stratified analysis showed that women were more sensitive to the adverse impact of PM2.5 that were men, and evidence was obtained of sex-based effect modification (P for interaction = 0.002). Our findings suggest that long-term exposure to PM2.5 is associated with osteoporotic fracture, particularly among women.

Functional outcomes and complications of hook plate for bony mallet finger: a retrospective case series study.

BACKGROUND: The treatment of mallet fracture using hook plate fixation was first introduced in 2007 and has subsequently shown excellent outcomes. Common complications, such as nail deformity and screw loosening, have also been reported. Very few studies have focused on these common complications or their prevention. In this study, we present the clinical outcomes and complications of our case series and describe the pitfalls and detailed solution of surgical tips to avoid common complications related to this procedure. METHODS: The retrospective case series of 16 patients with mallet fractures who underwent open reduction and hook plate fixation in our hospital from 2015 to 2020 were retrospectively reviewed. Data on extension lag, range-of-motion (ROM) of the distal interphalangeal joint (DIP) joint, the Disabilities of the Arm, Shoulder, and Hand (DASH) score, and surgical complications were collected and analysed. The clinical outcome was graded according to the Crawford mallet finger criteria. RESULTS: Sixteen patients were included in our analysis. The median DIP extension lag was 0° (range, 0° to 30°) and the median active DIP flexion angle was 60° (range, 40° to 90°). The median DASH score was 0 (range, 0-11.3). Fourteen patients with good and excellent results were satisfied with this treatment. The Complication rate in our patient series was 18%. Common complications reported in articles included wound necrosis, extension lag, nail deformity, and plate loosening. CONCLUSIONS: Despite the fact that the treatment of mallet fracture with hook plate fixation has satisfactory functional outcomes, pitfalls, including iatrogenic nail germinal matrix injury, unnecessary soft tissue dissection, and insufficient screw purchase, were still reported. To avoid complications, we suggest modifications of the skin incision, soft tissue dissection, and screw position.

Effect of oblique headless compression screw fixation for metacarpal shaft fracture: a biomechanical in vitro study.

BACKGROUND: Metacarpal shaft fracture is a common fracture in hand trauma injuries. Surgical intervention is indicated when fractures are unstable or involve considerable displacement. Current fixation options include Kirschner wire, bone plates, and intramedullary headless screws. Common complications include joint stiffness, tendon irritation, implant loosening, and cartilage damage. OBJECTIVE: We propose a modified fixation approach using headless compression screws to treat transverse or short-oblique metacarpal shaft fracture. MATERIALS AND METHODS: We used a saw blade to model transverse metacarpal neck fractures in 28 fresh porcine metacarpals, which were then treated with the following four fixation methods: (1) locked plate with five locked bicortical screws (LP group), (2) regular plate with five bicortical screws (RP group), (3) two Kirschner wires (K group), and (4) a headless compression screw (HC group). In the HC group, we proposed a novel fixation model in which the screw trajectory was oblique to the long axis of the metacarpal bone. The entry point of the screw was in the dorsum of the metacarpal neck, and the exit point was in the volar cortex of the supracondylar region; thus, the screw did not damage the articular cartilage. The specimens were tested using a modified three-point bending test on a material testing system. The maximum fracture forces and stiffness values of the four fixation types were determined by observing the force-displacement curves. Finally, the Kruskal-Wallis test was adopted to process the data, and the exact Wilcoxon rank sum test with Bonferroni adjustment was performed to conduct paired comparisons among the groups. RESULTS: The maximum fracture forces (median ± interquartile range [IQR]) of the LP, RP, HC, and K groups were 173.0 ± 81.0, 156.0 ± 117.9, 60.4 ± 21.0, and 51.8 ± 60.7 N, respectively. In addition, the stiffness values (median ± IQR) of the LP, HC, RP, and K groups were 29.6 ± 3.0, 23.1 ± 5.2, 22.6 ± 2.8, and 14.7 ± 5.6 N/mm, respectively. CONCLUSION: Headless compression screw fixation provides fixation strength similar to locked and regular plates for the fixation of metacarpal shaft fractures. The headless screw was inserted obliquely to the long axis of the metacarpal bone. The entry point of the screw was in the dorsum of the metacarpal neck, and the exit point was in the volar cortex of the supracondylar region; therefore the articular cartilage iatrogenic injury can be avoidable. This modified fixation method may prevent tendon irritation and joint cartilage violation caused by plating and intramedullary headless screw fixation.

Handgrip strength: a reliable predictor of postoperative early ambulation capacity for the elderly with hip fracture.

BACKGROUNDS: A common sequela of hip fracture is loss of ambulation capacity. Prediction of postoperative ambulation capacity is important for surgical and rehabilitation decision making. Handgrip strength is a quick and convenient tool for evaluating postoperative functional ability and outcome in variety of clinical conditions for the elderly and is associated with the use of walking aids. We propose that handgrip strength may be a good predictor for postoperative early ambulation. The purpose of our study was to investigate the contribution of handgrip strength in the prediction of postoperative early ambulation capacity in elderly hip fracture patients. METHODS: Clinical data of patients with low-energy hip fractures who received surgery from Jan 2018 to Dec 2019 were prospectively collected. The correlations of ambulation time with complication rate, age, gender, injured side, fracture classifications, surgical procedure, body mass index (BMI), and handgrip strength were analyzed. RESULTS: Sixty-three hip fracture patients were included in this study. Patients whose ambulation time was less than 3 days after the operation had significantly fewer postoperative complications (P = 0.006). Handgrip strength showed the strongest correlation with postoperative early ambulation capacity (P = 0.004). The handgrip strength threshold value for early ambulation was found to be 20.5 kg for male patients and 11.5 kg for female patients. CONCLUSION: Handgrip strength testis a quick and convenient tool for predicting postoperative early ambulation capacity. In elderly Asians, male patients with a handgrip strength above 20.5 kg and female patients with a handgrip strength above 11.5 kg suggest a high likelihood of early postoperative ambulation and a lower risk of complications after the hip surgery.

Effect of a figure-of-eight cerclage wire with two Kirschner wires on fixation strength for transverse metacarpal shaft fractures: an in vitro study with artificial bone.

BACKGROUND: Metacarpal shaft fractures are a common type of hand fracture. Despite providing strong fixation strength, plate fixation has numerous shortcomings. Concerning internal fixation with Kirschner wires (K-wires), although this approach is frequently used to treat metacarpal shaft fractures, the lack of functional stability may result in fixation failure. OBJECTIVE: To evaluate the effect of figure-of-eight cerclage wire on fixation for transverse metacarpal shaft fractures using two K-wires. MATERIALS AND METHODS: We used a saw blade to create transverse metacarpal shaft fractures in 14 fourth-generation artificial third metacarpal bones (Sawbones, Vashon, WA, USA), which were assigned to groups undergoing fixation with two K-wires (KP) or with two K-wires and figure-of-eight cerclage wire (KP&F8). All specimens were subjected to material testing, specifically cantilever bending tests. The maximum fracture force and stiffness of the two fixation types were determined on the basis of the force-displacement data. The Mann-Whitney U test was used to compare between-group differences in maximum fracture force and stiffness. RESULTS: The maximum fracture force of the KP group (median ± interquartile range = 97.30 ± 29.70 N) was significantly lower than that of the KP&F8 group (153.2 ± 69.50 N, p < 0.05; Figure 5a), with the median of the KP&F8 group exceeding that of the KP group by 57.5%. Similarly, stiffness was significantly lower in the KP group (18.14 ± 9.84 N/mm) than in the KP&F8 group (38.25 ± 23.49 N/mm; p < 0.05; Figure 5b), with the median of the KP&F8 group exceeding that of the KP group by 110.9%. CONCLUSION: The incorporation of a figure-of-eight cerclage wire increased the maximum fracture force and stiffness by 57.5 and 110.9%, respectively, compared with those achieved in standard two K-wire fixation. Therefore, hand surgeons are advised to consider the proposed approach to increase fixation strength.

Association of osteoporosis and varus inclination of the tibial plateau in postmenopausal women with advanced osteoarthritis of the knee.

BACKGROUND: Although varus inclination of the tibial plateau has increasingly been recognized as a major risk factor in the progression of Osteoarthritis of the knee (OA knee), little attention has been placed on the development of the varus inclination of the tibial plateau. Osteoporosis is a disease characterized by low bone mass and may increase the risk of a stress fracture in the proximal tibia. To date, risk factors for varus inclination of the tibial plateau are rarely reported. In this study, we investigated Bone Mineral Density (BMD) as a risk factor of varus inclination of the tibial plateau in postmenopausal women with advanced OA knee. METHODS: A total of 90 postmenopausal women with varus OA knee who had received a total knee arthroplasty in our department between January 2016 and December 2019 were reviewed. Certain factors may correlate to inclination of the tibial plateau (Medial Tibial Plateau Angle, MTPA), including age, operation side, Kellgren-Lawrence grade of OA knee, BMD, Body Mass Index (BMI), Lateral Distal Femur Angle (LDFA), lower extremity alignment (Hip-Knee-Ankle angle, HKAA), and history of both spinal compression fracture and hip fracture were collected and analyzed. RESULTS: Osteoporosis, lower extremity varus malalignment and age were significantly associated with varus inclination of the tibial plateau (MTPA) (P = 0.15, 0.013 and 0.033 respectively). For patients with a lower extremity varus malalignment (HKAA < 175°), osteoporosis (T-score ≤ -2.5) was significantly associated with inclination of the tibial plateau. For patients with a normal lower extremity alignment (HKAA ≥ 175°), no significant association was found between osteoporosis (T-score ≤ -2.5) and varus inclination of the tibial plateau. CONCLUSIONS: Osteoporosis, lower extremity varus malalignment and age are major risk factors for inclination of the tibial plateau in postmenopausal women with OA knee. More attention needs to be given to the progression of varus OA knee in postmenopausal women who simultaneously has osteoporosis and lower extremity varus malalignment.

Distal Finger Reconstruction by Bilateral Lateral Hallux Osteo-onychocutaneous Free Flap.

OBJECTIVE: In this report, we present our experience on the use of bilateral lateral hallux osteo-onychocutaneous free flaps for reconstruction of distal finger and the aesthetic and functional results of this technique in a series of cases. PATIENTS AND METHODS: From February 2005 to May 2015, 7 patients underwent finger reconstruction distal to the distal interphalangeal joint using the bilateral lateral hallux osteo-onychocutaneous free flaps. The mean age was 29.3 years (range, 24-33 years). The lateral hallux osteo-onychocutaneous flaps were harvested from bilateral donor sites. The size of each flap was designed based on the size of half distal finger defect. The lateral hallux osteo-onychocutaneous free flaps from both donor sites were combined to reconstruct the distal finger. More than 50% of hallux nail was preserved in each of donor sites, which was covered with a local flap. RESULTS: All flaps used for reconstruction survived without complications after surgery. The average length of follow-up was 93.4 months (range, 16-163 months). All reconstructed distal fingers showed good aesthetic appearance, except one that underwent a secondary debulking procedure. The average total active motion of the finger was 215.7 degrees (range, 200-230 degrees). Neither pain nor numbness sensation in the reconstructed fingers was complained by the patients. The donor site morbidity was minimal. All patients had pain-free and good function outcome in both feet. CONCLUSIONS: The use of the bilateral lateral hallux osteo-onychocutaneous free flaps may provide an option for distal finger reconstruction with satisfactory function and anesthetic outcomes with minimal hallux donor site morbidity.

3D-Printed Bioactive Calcium Silicate/Poly-ε-Caprolactone Bioscaffolds Modified with Biomimetic Extracellular Matrices for Bone Regeneration.

Currently, clinically available orthopedic implants are extremely biocompatible but they lack specific biological characteristics that allow for further interaction with surrounding tissues. The extracellular matrix (ECM)-coated scaffolds have received considerable interest for bone regeneration due to their ability in upregulating regenerative cellular behaviors. This study delves into the designing and fabrication of three-dimensional (3D)-printed scaffolds that were made out of calcium silicate (CS), polycaprolactone (PCL), and decellularized ECM (dECM) from MG63 cells, generating a promising bone tissue engineering strategy that revolves around the concept of enhancing osteogenesis by creating an osteoinductive microenvironment with osteogenesis-promoting dECM. We cultured MG63 on scaffolds to obtain a dECM-coated CS/PCL scaffold and further studied the biological performance of the dECM hybrid scaffolds. The results indicated that the dECM-coated CS/PCL scaffolds exhibited excellent biocompatibility and effectively enhanced cellular adhesion, proliferation, and differentiation of human Wharton's Jelly mesenchymal stem cells by increasing the expression of osteogenic-related genes. They also presented anti-inflammatory characteristics by showing a decrease in the expression of tumor necrosis factor-alpha (TNF-α) and interleukin-1 (IL-1). Histological analysis of in vivo experiments presented excellent bone regenerative capabilities of the dECM-coated scaffold. Overall, our work presented a promising technique for producing bioscaffolds that can augment bone tissue regeneration in numerous aspects.

Effect of Strontium Substitution on the Physicochemical Properties and Bone Regeneration Potential of 3D Printed Calcium Silicate Scaffolds.

In this study, we synthesized strontium-contained calcium silicate (SrCS) powder and fabricated SrCS scaffolds with controlled precise structures using 3D printing techniques. SrCS scaffolds were shown to possess increased mechanical properties as compared to calcium silicate (CS) scaffolds. Our results showed that SrCS scaffolds had uniform interconnected macropores (~500 µm) with a compressive strength 2-times higher than that of CS scaffolds. The biological behaviors of SrCS scaffolds were assessed using the following characteristics: apatite-precipitating ability, cytocompatibility, proliferation, and osteogenic differentiation of human mesenchymal stem cells (MSCs). With CS scaffolds as controls, our results indicated that SrCS scaffolds demonstrated good apatite-forming bioactivity with sustained release of Si and Sr ions. The in vitro tests demonstrated that SrCS scaffolds possessed excellent biocompatibility which in turn stimulated adhesion, proliferation, and differentiation of MSCs. In addition, the SrCS scaffolds were able to enhance MSCs synthesis of osteoprotegerin (OPG) and suppress macrophage colony-stimulating factor (M-CSF) thus disrupting normal bone homeostasis which led to enhanced bone formation over bone resorption. Implanted SrCS scaffolds were able to promote new blood vessel growth and new bone regeneration within 4 weeks after implantation in critical-sized rabbit femur defects. Therefore, it was shown that 3D printed SrCS scaffolds with specific controllable structures can be fabricated and SrCS scaffolds had enhanced mechanical property and osteogenesis behavior which makes it a suitable potential candidate for bone regeneration.

Bioactive calcium silicate/poly-ε-caprolactone composite scaffolds 3D printed under mild conditions for bone tissue engineering.

The present study provides a solvent-free processing method for establishing the ideal porous 3-dimension (3D) scaffold filled with different ratios of calcium silicate-based (CS) powder and polycaprolactone (PCL) for 3D bone substitute application. Characterization of hybrid scaffolds developed underwent assessments for physicochemical properties and biodegradation. Adhesion and growth of human Wharton's Jelly mesenchymal stem cells (WJMSCs) on the CS/PCL blended scaffold were investigated in vitro. Cell attachment and morphology were examined by scanning electron microscope (SEM) and confocal microscope observations. Colorimetric assay was tested for assessing cell metabolic activity. In addition, RT-qPCR was also performed for the osteogenic-related and angiogenesis-related gene expression. As a result, the hydrophilicity of the scaffolds was further significantly improved after we additive CS into PCL, as well as the compressive strength up to 5.8 MPa. SEM showed that a great amount of precipitated bone-like apatite formed on the scaffold surface after immersed in the simulated body fluid. The 3D-printed scaffolds were found to enhance cell adhesion, proliferation and differentiation. Additionally, results of osteogenesis and angiogenesis proteins were expressed obviously greater in the response of WJMSCs. These results indicate the CS/PCL composite exhibited a favorable bioactivity and osteoconductive properties that could be served as a promising biomaterial for bone tissue engineering scaffolds.

Enhancement of placenta growth factor expression by oncostatin M in human rheumatoid arthritis synovial fibroblasts.

Oncostatin M (OSM) belongs to IL-6 subfamily and is mostly produced by T lymphocytes. High levels of OSM are detected in the pannus of rheumatoid arthritis (RA) patients and it may arouse the inflammation responses in joints and eventually leads to bone erosion. Placenta growth factor (PLGF) is an angiogenic factor and highly homologous with vascular endothelial growth factor (VEGF). It has been recently reported that PLGF is highly expressed in synovial tissue and enhances the production of proinflammatory cytokines including TNF-α and IL-6. Here, we demonstrated that OSM increased mRNA and protein levels of PLGF in a time- and concentration-dependent manner in RA synovial fibroblasts. Inhibitors of JAK3 and PI3K antagonized OSM-induced production of PLGF. OSM enhanced the phosphorylation of Tyr705-STAT3, Ser727-STAT3, Ser473-Akt, and increased the nuclear translocation of phosphorylated STAT3 time-dependently. Transfection of dominant negative Akt or application of PI3K inhibitorLY294002 significantly inhibited p-Tyr705-STAT3, p-Ser727-STAT3, and PLGF expression, indicating that Akt is involved in JAK3/STAT3/PLGF signaling cascade. To further examine whether STAT3 binds to the promoter region of PLGF, Chip assay was used and it was found that OSM could bind with PLGF promoter, which was inhibited by JAK3 and PI3K inhibitors. Accumulation of PLGF in the pannus may contribute to the inflammation, angiogenesis and joints destruction in RA patients. These findings demonstrated the important role of OSM in the pathology network of RA and provided novel therapeutic drug targets for RA treatment.

Correction: Additive manufacturing of barium-doped calcium silicate/poly-ε-caprolactone scaffolds to activate CaSR and AKT signalling and osteogenic differentiation of mesenchymal stem cells.

Correction for 'Additive manufacturing of barium-doped calcium silicate/poly-ε-caprolactone scaffolds to activate CaSR and AKT signalling and osteogenic differentiation of mesenchymal stem cells' by Yung-Cheng Chiu et al., J. Mater. Chem. B, 2023, 11, 4666-4676, https://doi.org/10.1039/D3TB00208J.

Additive manufacturing of barium-doped calcium silicate/poly-ε-caprolactone scaffolds to activate CaSR and AKT signalling and osteogenic differentiation of mesenchymal stem cells.

3D-printed scaffolds are suitable for patient-specific implant preparation for bone regeneration in large-scale critical bone defects. In addition, these scaffolds should have mechanical and biological properties similar to those of natural bone tissue. In this study, 3D-printed barium-doped calcium silicate (BaCS)/poly-ε-caprolactone (PCL) composite scaffolds were fabricated as an alternative strategy for bone tissue engineering to achieve appropriate physicochemical characteristics and stimulate osteogenesis. Scaffolds containing 10% Ba (Ba10) showed optimal mechanical properties, preventing premature scaffold degradation during immersion while enabling ion release in a sustained manner to achieve the desired therapeutic goals. In addition, Wharton's jelly mesenchymal stem cells (WJMSCs) were used to assess biocompatibility and osteogenic differentiation behaviour. WJMSCs were cultured on the scaffold and permeabilised via ICP to analyse the presence of Si and Ba ions in the medium and cell lysates, suggesting that the ions released by the scaffold could effectively enter the cells. The protein expression of CaSR, PI3K, Akt, and JNK confirmed that CaSR could activate cells cultured in Ba10, thereby affecting the subsequent PI3k/Akt and JNK pathways and further promoting osteogenic differentiation. The in vivo performance of the proposed scaffolds was assessed using micro-CT and histological slices, which revealed that the BaCS scaffolds could further enhance bone regeneration, compared with bare scaffolds. These results suggest the potential use of 3D-printed BaCS/PCL scaffolds as next-generation substitutes for bone regeneration.

Biomechanical study of the fixation ability of the dorsal and volar locking plate for transverse metacarpal neck fractures.

Metacarpal neck fracture is one of the most common types of hand fractures; the literature suggests that applying a bone plate on the dorsal side provides higher fixation strength than that provided by other fixation methods. However, bone plate fixation on the dorsal side may result in postoperative tendon adhesion. So far, no studies have investigated the fixation of metacarpal neck fractures on the volar side by using a bone plate. The objective of this study was to investigate the differences in the fixation results between bone plate fixation on the dorsal side and bone plate fixation on the volar side of the metacarpal in the case of a metacarpal neck fracture. A saw blade was used to create a transverse metacarpal neck fracture on 14 artificial metacarpal bone specimens. The specimens were divided into 2 groups depending on the fixation method: a volar locking plate (VLP) group and a dorsal locking plate (DLP) group. All specimens were subjected to a cantilever bending test on a material testing system, and a force-displacement curve was used to measure the yield force and stiffness, which served as an indicator of the fixation ability of the 2 fracture fixation methods. For the experimental results, the Mann-Whitney U test was used to compare the fixation abilities of the 2 fixation methods. In terms of yield force, the DLP group (266.9 ± 68.3 N) scored significantly higher than the VLP group (32.6 ± 2.7 N) (P < .05); expressed in terms of median, the DLP group scored 8.2 times higher than the VLP group. Similarly, in terms of stiffness, the DLP group (69.0 ± 13.4 N/mm, median ± interquartile range) scored significantly higher than the VLP group (12.9 ± 1.4 N/mm) (P < .05); expressed in terms of median, the DLP group scored 5.3 times higher than the VLP group. The fixation strength of volar bone plates is only about one-third of that of dorsal bone plates.

Effect of intraoperative hand-grip position on surgical outcome of thumb carpometacarpal arthrodesis.

BACKGROUND: A variety of surgical techniques had been developed over the past few decades for treating thumb carpometacarpal joint (CMCJ) osteoarthritis (OA). However, there are currently no accepted consensus on the ideal treatment for thumb CMCJ OA. Arthrodesis was one of the widely popular treatment methods; however, studies have showed that non-union rates were as high as 50%, with higher complications such as osteoarthritis of neighbouring joints and higher revision surgeries required as compared to other surgical methods. Patients with arthrodesis were also reported to have decreased thumb range of motion and loss of opponens function. Currently, there are numerous intraoperative positioning techniques for arthrodesis which could be confusing for young surgeons. With recent developments of fixation plates and better understanding of the wrist anatomy, this retrospective review aimed to evaluate the efficacy of our intraoperative hand-grip positioning method for arthrodesis of thumb CMCJ OA. What are the postoperative functional outcomes of (1) T-hook plates and (2) our intraoperative hand-grip positioning method for Eaton III thumb CMCJ OA arthrodesis by evaluating pain visual analogue scale (VAS) score, Disabilities of the Arm, Shoulder and Hand questionnaires (DASH), Mayo Wrist scores, capability of thumb opposition (Kapandji score), and comparing pre- and postoperative grip and pinch strength? METHODS: Twenty patients with CMCJ OA underwent arthrodesis using our intraoperative hand-grip positioning method and T-hook plates and screws (Acumed, USA). Patients were evaluated preoperatively and at 1, 3, 6 and 12 months postoperatively. Radiologic assessment including fusion evaluation, evaluation of radial and palmar abduction angles was done on hand X-rays. RESULTS: Twenty patients with a minimum follow-up duration of 12 months were included in this study. 100% fusion rate was achieved with only 1 case of complication involving radial sensory nerve neuropathy which was resolved after removal of implant and neurolysis. Significant improvement in pain and Mayo Wrist scores were noted 3 months postoperatively, whilst DASH score exhibited significant improvements after 6 months of follow-up (p < 0.05). Even though there were no significant differences observed between preoperative and postoperative grip strength, pinch strength and Kapandji scores, positive recovery trends were noted for all parameters with these functions surpassing preoperative levels after 12 months of follow-up. Significant improvements on hand X-rays were also noted for both postoperative radial and palmar abduction angles. CONCLUSIONS: There is currently no consensus on the ideal treatment method for thumb CMCJ OA. In this study, we would like to propose a simple intraoperative hand-grip positioning method with T-hook plates for arthrodesis. As seen from our results, our technique was able to provide satisfactory and replicable postoperative results and thus we would like to propose our hand-grip positioning method with T-hook plates fixation for subsequent treatment of patients with Eaton stage III thumb CMCJ OA.

Involvement of 15-lipoxygenase in the inflammatory arthritis.

15-Lipoxygenase (15-LOX) is involved in many pathological processes. The aim of this study is to examine the role of 15-LOX in the matrix metalloproteinase (MMP) expression and inflammatory arthritis. It was found that treatment of 15-LOX downstream product of 15-(S)-HETE (15-S-hydroxyeicosatetraenoic acid) increased the mRNA and protein levels of MMP-2 in rheumatoid arthritis synovial fibroblast (RASF) derived from rheumatoid arthritis patients. The enhancement effect of 15-(S)-HETE was antagonized by the addition of LY294002 (PI3K inhibitor) and PDTC (NF-κB inhibitor). Treatment of 15-(S)-HETE increased the phosphorylation of AKT, nuclear translocation of p65 and the breakdown of IκBα. TNF-α and IL-1ß are the key cytokines involved in arthritis and also increase the activity of MMP-2 in RASF, which was antagonized by pretreatment with 15-LOX inhibitor PD146176 or knockdown of 15-LOX. It was also found that these two cytokines increased the expression of 15-LOX in RASF. Treatment of glucocorticoid but not NSAIDs inhibited 15-(S)-HETE-induced expression of MMP-2. In comparison with wild-type mice, adjuvant-induced arthritis and MMP-2 expression in synovial membrane were markedly inhibited in 15-LOX knockout (KO) mice. These results indicate that 15-LOX plays an important role in the disease progression of arthritis and may be involved in the inflammatory action induced by TNF-α and IL-1ß. 15-LOX is thus a good target for developing drugs in the treatment of inflammatory arthritis.