ObjectiveTo investigate whether exosomes derived from miR-27a-overexpressing human umbilical vein endothelial cells (HUVECs)—exo (miR-27a) can promote bone regeneration and improve glucocorticoids (GC) induced osteonecrosis of femoral head (ONFH) (GC-ONFH).MethodsThe exo (miR-27a) were intended to be constructed and identified by transmission electron microscopy, nanoparticle tracking analysis, Western blot, and real-time fluorescent quantitative PCR (qRT-PCR). qRT-PCR was used to evaluate the effect of exo (miR-27a) in delivering miR-27a to osteoblasts (MC3T3-E1 cells). Alkaline phosphatase staining, alizarin red staining, and qRT-PCR were used to evaluate its effect on MC3T3-E1 cells osteogenesis. Dual-luciferase reporter (DLRTM) assay was used to verify whether miR-27a targeting Dickkopf WNT signaling pathway inhibitor 2 (DKK2) was a potential mechanism, and the mechanism was further verified by qRT-PCR, Western blot, and alizarin red staining in MC3T3-E1 cells. Finally, the protective effect of exo (miR-27a) on ONFH was verified by the GC-ONFH model in Sprague Dawley (SD) rats.ResultsTransmission electron microscopy, nanoparticle tracking analysis, Western blot, and qRT-PCR detection showed that exo (miR-27a) was successfully constructed. exo (miR-27a) could effectively deliver miR-27a to MC3T3-E1 cells and enhance their osteogenic capacity. The detection of DLRTM showed that miR-27a promoted bone formation by directly targeting DDK2. Micro-CT and HE staining results of animal experiments showed that tail vein injection of exo (miR-27a) improved the osteonecrosis of SD rat GC-ONFH model.Conclusionexo (miR-27a) can promote bone regeneration and protect against GC-ONFH to some extent.
ObjectiveTo evaluate hip function and reinfection of the patients with hip infection sequelae after total hip arthroplasty (THA) treatment.MethodsA clinical data of 31 patients (31 hips) with hip infection sequelae, who were treated with THA between June 2010 and May 2017, was retrospectively analyzed. There were 18 males and 13 females, with an average age of 46.1 years (range, 20-71 years). There were pyogenic infection in 17 cases, tuberculous infection in 9 cases, and unknown source of infection in 5 cases. The average time from infection to cure was 13.9 months (range, 6-25 months). The average time from cure to operation was 23.4 years (range, 6-58 years) for patients with confirmed source of infection. According to Kim classification, 12 cases were rated as typeⅠ, 9 as typeⅡ, and 10 as type Ⅲ. There were 21 cases of osteoarthritis after dysplasia, 7 cases of pathologic dislocation, and 3 cases of hip ankylosis. After operation, the infection was assessed by physical signs and laboratory tests; X-ray film of the hip was taken to assess the skeletal structure of the hip and infectious lesion; the length of the lower limb was measured, and the function of the hip joint was evaluated by Harris score.ResultsAll patients were followed up 10-63 months (mean, 34 months). The result of bacterial culture was negative. The incisions healed by first intention. The sciatic nerve stimulation occurred in 1 case and posterior dislocation of the joint occurred in 1 case after operation. There was no recurrence of infection and no aseptic loosening of the prosthesis. According to Harris score, the function of the hip was rated as excellent in 8 cases, good in 19 cases, and fair in 4 cases at last follow-up; and the excellent and good rate of hip joint function was 87%. X-ray films showed no patchy bone density reduction, spot hardening, or light areas. The length of affected limb was not fully equal with the unaffected limb in 5 cases, and the difference between two sides ranged from 0.4 to 1.3 cm (mean, 0.6 cm). At last follow-up, all patients had no obvious claudication or sensation of unequal length.ConclusionTHA can obtain satisfactory hip function and has low risk of infection recurrence for the patients with hip infection sequelae, who were assessed as the hip infection in a dormant state.
Objective To investigate the accuracy and reliability of augmented reality (AR) technique in locating the perforating vessels of the posterior tibial artery during the repair of soft tissue defects of the lower limbs with the posterior tibial artery perforator flap. Methods Between June 2019 and June 2022, the posterior tibial artery perforator flap was used to repair the skin and soft tissue defects around the ankle in 10 cases. There were 7 males and 3 females with an average age of 53.7 years (mean, 33-69 years). The injury was caused by traffic accident in 5 cases, bruising by heavy weight in 4 cases, and machine injury in 1 case. The size of wound ranged from 5 cm×3 cm to 14 cm×7 cm. The interval between injury and operation was 7-24 days (mean, 12.8 days). The CT angiography of lower limbs before operation was performed and the data was used to reconstruct the three-dimensional images of perforating vessels and bones with Mimics software. The above images were projected and superimposed on the surface of the affected limb using AR technology, and the skin flap was designed and resected with precise positioning. The size of the flap ranged from 6 cm×4 cm to 15 cm×8 cm. The donor site was sutured directly or repaired with skin graft. Results The 1-4 perforator branches of posterior tibial artery (mean, 3.4 perforator branches) in 10 patients were located by AR technique before operation. The location of perforator vessels during operation was basically consistent with that of AR before operation. The distance between the two locations ranged from 0 to 16 mm, with an average of 12.2 mm. The flap was successfully harvested and repaired according to the preoperative design. Nine flaps survived without vascular crisis. The local infection of skin graft occurred in 2 cases and the necrosis of the distal edge of the flap in 1 case, which healed after dressing change. The other skin grafts survived, and the incisions healed by first intention. All patients were followed up 6-12 months, with an average of 10.3 months. The flap was soft without obvious scar hyperplasia and contracture. At last follow-up, according to the American Orthopedic Foot and Ankle Association (AOFAS) score, the ankle function was excellent in 8 cases, good in 1 case, and poor in 1 case. Conclusion AR technique can be used to determine the location of perforator vessels in the preoperative planning of the posterior tibial artery perforator flap, which can reduce the risk of flap necrosis, and the operation is simple.