ObjectiveTo evaluate the biological effect on vascularization during bone repair of prevascularized porous β-tricalcium phosphate (β-TCP) tissue engineered bone (hereinafter referred to as prevascularized tissue engineered bone), which was established by co-culture of endothelial progenitor cells (EPCs) and bone marrow mesenchymal stem cells (BMSCs) based on tissue engineering technology. Methods EPCs and BMSCs were isolated from iliac bone marrow of New Zealand white rabbits by density gradient centrifugation and differential adhesion method. The cells were identified by immunophenotypic detection, BMSCs-induced differentiation, and EPCs phagocytosis. After identification, the third-generation cells were selected for subsequent experiments. First, in vitro tubule formation in EPCs/BMSCs direct contact co-culture (EPCs/BMSCs group) was detected by Matrigel tubule formation assay and single EPCs (EPCs group) as control. Then, the prevascularized tissue engineered bone were established by co-culture of EPCs/BMSCs in porous β-TCP scaffolds for 7 days (EPCs/BMSCs group), taking EPCs in porous β-TCP scaffolds as a control (EPCs group). Scanning electron microscopy and laser scanning confocal microscopy were used to observe the adhesion, proliferation, and tube formation of cells. Femoral condyle defect models of 12 New Zealand white rabbits were used for implantation of prevascularized tissue engineered bone as the experimental group (n=6) and porous β-TCP scaffold as the control group (n=6). The process of vascularization of β-TCP scaffolds were observed. The numbers, diameter, and area fraction of neovascularization were quantitatively evaluated by Microfill perfusion, Micro-CT scanning, and vascular imaging under fluorescence at 4 and 8 weeks. ResultsThe isolated cells were BMSCs and EPCs through identification. EPCs/BMSCs co-culture gradually formed tubular structure. The number of tubules and branches, and the total length of tubules formed in the EPCs/BMSCs group were significantly more than those in the EPCs group on Matrigel (P<0.05) after 6 hours. After implanting and culturing in porous β-TCP scaffold for 7 days, EPCs formed cell membrane structure and attached to the material in EPCs group, and the cells attached more tightly, cell layers were thicker, the number of cells and the formation of tubular structures were significantly more in the EPCs/BMSCs group than in the EPCs group. At 4 weeks after implantation, neovascularization was observed in both groups. At 8 weeks, remodeling of neovascularization occurred in both groups. The number, diameter, and area fraction of neovascularization in the experimental group were higher than those in the control group (P<0.05), except for area fraction at 4 weeks after implantation (P>0.05). ConclusionThe prevascularized tissue engineered bone based on direct contact co-culture of BMSCs and EPCs can significantly promote the early vascularization process during bone defects repair.
Objective To explore the operative methods and effectiveness of open reduction and internal fixation for Bosworth fracture. Methods Between January 2005 and January 2012, 6 patients with Bosworth fractures caused by sprain were treated. There were 4 males and 2 females with an average age of 45.8 years (range, 24-73 years). The time from injury to operation was 1-5 days (mean, 1.8 days). They were all closed fractures. According to Lauge-Hansen classification, 6 cases were classified as supination-external rotation type. The surgical treatments included open reduction and internal fixation by plate and screws. Results Infection occurred in 1 case and was cured after dressing changing; primary healing of incision was obtained in the other 5 cases. Six patients were followed up 15 months on average (range, 12-24 months). The X-ray films showed fracture healing in all cases, with an average healing time of 9.5 weeks (range, 8-13 weeks). No loosening or breaking of internal fixator was observed during follow-up. The average full load-walking time was 12 weeks (range, 10-17 weeks). According to the ankle and hindfoot scale of American Orthopaedic Foot and Ankle Society (AOFAS), the average score was 89.5 (range, 81-94). Conclusion For Bosworth fractures, good results can be achieved by early diagnosis, open reduction and internal fixation.
Objective To evaluate the primary cl inical effectiveness of Austin metatarsal osteotomy combined with transection of adductor muscle and transverse metatarsal l igament for treating mild or moderate hallux valgus through a single medial incision. Methods Between May 2006 and January 2009, 41 patients (45 feet) with mild or moderate hallux valgus were treated. There were 9 males (10 feet) and 32 females (35 feet) with an average age of 45.3 years (range, 23-71 years). The hallux valgus angle (HVA) was (33.1 ± 1.4)°, and the first and second inter-metatarsal angle was (20.4 ±1.1)°. The American Orthopaedic Foot and Ankle Society (AOFAS) ankle and hindfoot score of the affected foot’s function was 47.2 ± 3.7. A longitudinal medial incision was made at the first metatarsophalangeal joint. By the incision, Austin metatarsal osteotomy and lateral soft tissue release (including transection of adductor muscle and the transverse metatarsal l igament) were performed at the same time. Results During operation, 1 case had superficial peroneal nerve branch injury and suture repair was done microsurgically. All incisions healed by first intention postoperatively. All patients were followed up 16-36 months (mean, 26 months). Medial forefoot numbness occurred in 2 feet at 3 days after operation and rel ieved within 6 weeks. The X-ray films showed bone heal ing at osteotomy site within 8 weeks after operation. At last follow-up, the HVA was (10.7 ± 1.7)°, showing significant difference when compared with preoperative value (t=22.32, P=0.00), and the first and second inter-metatarsal angle was (12.1 ± 1.7)°, also showing significant difference when compared with preoperative value (t=21.17, P=0.03). The postoperative AOFAS ankle and hindfoot score of the affected foot’s function was 84.9 ± 4.5, showing significant difference when compared with preoperative score (t=20.75, P=0.01). No foot hallux varus, hallux valgus, or metatarsal necrosis occurred during follow-up. Conclusion The Austin metatarsal osteotomy combined with transection of adductor muscle, transverse metatarsal l igament through a single medial incision can effectively correct the mild or moderate hallux valgus, and avoid the scar and injury of deep peroneal nerve branches by traditional lateral incision.