Clinical applications of internal fixation via the volar approach with pronator quadratus preservation for distal radius fractures.

BACKGROUND: The purpose of this study is to investigate the success rate of volar plate treatment of distal radius fractures with preservation of the pronator anterior muscle; the incidence of complications, such as infection, vascular nerve injury, and tendon injury; fracture healing rate; and changes in muscle anatomy. METHODS: The Henry approach was adopted to treat distal radius fractures with pronator quadratus (PQ) preservation on a trial basis. Between June 2015 and January 2017, 46 cases of distal radius fractures were considered according to the Arbeitsgemeinschaft für Osteosynthesefragen (AO) classification. The PQ was preserved, the distal margin was exposed, and a fracture reset was completed by pulling the muscles toward the near side. The K-wires were temporarily fixed, and the plate was placed by a plate channel. The mean operation duration was 52 min and the average blood loss was approximately 30 mL. There were no implant failures, adhesions requiring tenolysis, and tendon rupture. No patient developed carpal tunnel syndrome. All fractures healed without infection, radial artery injury, nerve damage, tendon rupture, and nonunion. A guider was applied to implant a screw under the muscle. RESULTS: In total, 46 patients with PQ preservation between ages 29 to 52 were performed distal radius fracture surgery. AO classification revealed that there were four cases of type A, seven cases of type B3, 10 cases of type C1, 13 cases of type C2, and 12 cases of type C3. For most fractures, such as Types A, B3, C1, C2, and C3, the fracture sites were located around the muscle distal margin. Thus, slight pulling of the muscles to the near side can reveal the fracture, and surgery with PQ preservation can be implemented. The postoperative muscle structures found during hardware removal procedures were similar to the muscle structures before the first operation. The radiographic outcome of fracture fixation was satisfactory. DISCUSSION: Surgery with PQ preservation is suitable for most distal radius fractures other than Types B1 and B2. For a small part of fractures involving the shaft of the radius, the PQ needed to be partially cut off to complete the operation. The postoperative muscle structures were close to normal.

Asiaticoside reverses M2 phenotype macrophage polarization-evoked osteosarcoma cell malignant behaviour by TRAF6/NF-κB inhibition.

CONTEXT: M2 phenotype macrophage polarization is an attractive target for therapeutic intervention. Asiaticoside (ATS) has multiple pharmacological functions. OBJECTIVE: This study investigates the effect of ATS on M2 phenotype macrophage polarization in osteosarcoma. MATERIALS AND METHODS: The differentiation of human THP-1 monocytes into M0 phenotype macrophages was induced by 100 nM phorbol myristate acetate for 24 h, and treated with 20 ng/mL IL-4 and 20 ng/mL IL-13 for 48 h to obtain M2 phenotype macrophages. The function of ATS on the growth and invasion was investigated by cell counting kit-8, transwell, and western blot under the co-culture of M2 phenotype macrophages and osteosarcoma cells for 24 h. The mechanism of ATS on osteosarcoma was assessed using molecular experiments. RESULTS: ATS reduced the THP-1 cell viability with an IC50 of 128.67 µM. Also, ATS repressed the M2 phenotype macrophage polarization induced by IL-4/IL-13, and the effect was most notably at a 40 µM dose. ATS (40 µM) restrained the growth and invasion of osteosarcoma cells induced by M2 phenotype macrophages. In addition, ATS reduced the tumour necrosis factor receptor-associated factor 6 (TRAF6)/NF-κB activity in osteosarcoma cells and the TRAF6 knockdown reduced the growth and invasion of osteosarcoma cells induced by M2 phenotype macrophages. TRAF6 (2 µg/mL) attenuated the inhibitory effect of ATS on the growth and invasion of osteosarcoma cells caused by M2 phenotype macrophages. In vivo studies further confirmed ATS (2.5, 5, or 10 mg/kg) repressed osteosarcoma tumour growth. DISCUSSION AND CONCLUSIONS: ATS reversed M2 phenotype macrophage polarization-evoked osteosarcoma cell malignant behaviour by reducing TRAF6/NF-κB activity, suggesting ATS might be a promising drug for the clinical treatment of osteosarcoma.