Objective To investigate the clinical effects of synthetic medical calcium phosphate and calcium sulfate as the bone replacements for bone defects.MethodsA total of 85 bone trauma patients combined with bone defects treated between February 2000 and October 2011 were randomized to calcium phosphate group ( n =43 ) and calcium sulfate group ( n =42 ) according to bone substitutes.The patients had orthopedic conventional treatment and then received external fixation ( external fixators,plasters) or internal fixation (plates,needles).Forty-three patients in the calcium phosphate group were all treated with medical calcium phosphate and 42 patients in the calcium sulfate group were all treated with medical calcium sulfate.Postoperative complications,fracture healing time and bone substitute absorption time of the two groups were observed and compared.ResultsAfter artificial bone filling for bone defects,all fractures were healed,with average healing time of 12.5 weeks ( range,9-17 weeks) in the calcium phosphate group and 11.3 weeks (range,7-15 weeks) in the calcium sulfate group.No complications or abnormal reactions occurred in the calcium sulfate group,whereas four patients with incision exudation was founded in the calcium phosphate group,and was cured after dressing change.The average follow-up period was 54.5 weeks (range,14-70 weeks).Average absorption time of bone substitute for the calcium phosphate group was 7.3 weeks,longer than that for the calcium sulfate group (P ＜ 0.05 ).Conclusions Medical calcium phosphate and calcium sulfate artificial bones can both be used as bone substitutes and are characterized by convenience,safety and good healing under the auxiliary of internal and external fixators.The calcium sulfate is sturdier and has relatively stronger supporting ability than the calcium phosphate.As the bone substitute,the calcium sulfate has more precise clinical effects,fewer complications and shorter healing time than the calcium phosphate.

Objective To explore the feasibility of Ilizarov technique in managing large tibia defects combined with soft tissue defects.Methods A total of 24 patients with large tibial defects combined with soft tissue defects caused by compound open tibial fractures were fixed with Ilizarov technique from September 2003 to September 2010.All patients belonged to open tibial fractures,including 20 patients with Gustilo type Ⅲ B and four with Gustilo type Ⅲ C.After debridement,the soft tissue defect areas was 10 cm ×6 cm and the bone defect was(8 ±4)cm.Fifteen patients with tibial defects ＜5 cm were treated with one stage debridement,fibula resection and tibial defect end compression.The other nine patients with tibial defect ＞ 5 cm were managed by one stage debridement,bone transport and bone lengthening.Then,15 patients were treated with one stage debridement,wound closure or wound reduction,bone grafting treatment and second stage cleansing of the incarcerated skin and fracture end.Results All patients were followed up for average 14 months(10-24 months),which showed reconstruction of the bone defects,restoration of the limb length,fracture healing and less than 2 cm difference between health limb and contralateral limb.One patient experienced common peroneal nerve palsy after operation,but recovered three months later.Of all,19 patients recovered without extra surgery,three restored with skin graft and two received skin flap.Conclusion Ilizarov technique is an effective option for treating the tibial defects combined with soft tissue defects at one stage.

Objective To investigate feasibility and effect of external fixator plus steel plate in treatment of open tibiofibular fractures combined with tibial defect.Methods The study involved 21 patients with open fractures of tibia and fibula (15 patients with type Gastilo ⅢA,five with type Gastilo ⅢB and one with type Gastilo ⅢC) with concurrent tibial defect of 2-6 cm.External fixator plus fibular steel plate was performed at the first stage,followed by iliac bone grafting for bone defect at the second stage.Results All patients showed successful reconstruction of the tibial defects with length difference between affected and healthy extremities less than 2 cm in follow-up for (14.0 ± 10.5) months (range,8-24 months).Meanwhile,no talipes equinovarus existed.Conclusions External fixator plus steel plate is an effective method for treating open tibiofibular fractures combined with tibial defect.The length and function of the extremities of patients with open tibiofibular fractures combined with tibial defect of less than 6 cm can be successfully restored.

Objective To investigate the changes in Wnt/β-catenin,bone morphogenic protein (BMP),estrogen receptor (ER) and insulin-like growth factor (IGF) signaling pathways in bone marrow mesenchymal stem cells (BMSCs) differentiation to the osteoblasts after spinal cord injury (SCI) and understand the mechanism of osteoporosis after SCI.Methods Forty 6-week-old male rats were divided into SCI group (n =20) and control group (n =20) according to the random number table.Rats in SCI group were submitted to laminar osteotomy at T10-12 and given lower thoracic cord sharp transection.In control group,rat lower thoracic cord was only exposed without transaction.Femoral bone marrow density (BMD) of rat right side was determined at postoperative 3 months.Femoral bone marrow was harvested from rat left side.After BMSCs osteoblast differentiation,cells were harvested and used for examining expression of genes associated with the signaling pathways in the two groups using microarray technology and real-time PCR analysis.Results BMD in SCI group was significantly lower in the ephiphyses and metaphyses[(0.176 ± 0.017)g/cm2 and (0.170 ±0.016)g/cm2] compared to that in control group [(0.257 ± 0.023) g/cm2 and (0.196 ± 0.013) g/cm2,P ＜0.05].Microarray and PCR analysis revealed Wnt/β-catenin (eg.Wnt1,Wnt3a,Wnt5a,Lrp5,Ctnnb1,Lef1 and Axin),BMP (Tgfb1 and Bmpr1),IGF -1 (eg.IGF1 R,c-fos and c-Jun),and ER (eg.Esr1) signaling pathways in osteoblasts were significantly down-regulated in SCI group compared to these in control group (P ＜ 0.05).Conclusions The Wnt/β-catenin,BMP,ER,and IGF-1 signaling pathways in osteoblasts are significantly down-regulated after SCI,resulting in profound BMD loss.This indicates that these signaling pathways are implicated in the osteoporosis after SCI.