ABSTRACT
Objective To investigate the effects of combined use of an allograft and vascularized fibular flap for the reconstruction of bone defects after intercalary resection of long bone malignancy.Methods From April 2006 to October 2009,19 patients that had intercalary resection of long bone malignancy (5 in humerus,7 in femur,7 in tibia)underwent reconstruction with an allograft and vascularized fibula construct,including 11 males and 8 females with an average age of 18.5 years.The average length of the defect was 13.2±4.3 cm.Free vascularized fibula flaps were used in 16 patients and ipsilateral pedicle vaseularized fibula grafts in 3.Time to union was recorded through evaluation of plain radiographs.Bone scan was used to evaluate the viability of the vascularized fibula.Patients were examined oncologically and radiographically and were assessed functionally with MSTS-93.Results The mean follow-up time was 27.5 months.The average length of the fibula flap was 17.9±5.2 cm.Viability of the fibular grafts was verified in all cases.The average time for bone union at allograft-host junction was 11.3±2.8 months in femur,14.1±3.3 in tibia,6.8±1.4 in humerus,respectively.The MSTS-93 average score at final follow-up was 95.2% in upper extremity and 91.8% in lower extremity.The oncology result in patients with follow-up more than 2 years was continuous disease free in 11 patients.no evidence of disease after recurrence following resection in 1,alive with tumor in 1,and died of lung metastasis in 1.Conclasion Vascularized fibular flap in combination with massive allograft provide an option for reconstruction of large bony defects after long bone malignancy extirpation.The viability of the fibula is a cornerstone in success of reconstruction that prevents allograft nonunion and result in decreased time to bone healing,leading to earlier patient's recovery of function.
ABSTRACT
Objective To evaluate the clinical outcomes of a hovel porous β-tricalcium phosphate (β-TCP)and control allograft for the repair of lacunar bone defects caused by solitary bone cyst curettage.Methods From January 2003 to December 2008,the patients with solitary bone cyst were randomized into an experimental(55 cases)and a control(40 cases)group.The control group received particulate allograft bone as the graft material,and the experimental group received β-TCP.At 1 week,1,2,3,6,12,24,48months after surgery,a new radiographic scoring system was employed to calculate the biodegradation of bone graft and evaluate the influence of multiple factors.Histologic characteristic of the degradation process of β-TCP were also evaluated.Results All the cases were followed up for average 28.4 months.Radiographic semi-quantitative analysis revealed that the biodegradation effieiencies were not significantly difierent between β-TCP and allografts(P=0.424).Degradation percentage of the implanted β-TCP or allograft was higher in younger patients than those in the older ones.Degradation of β-TCP was significantly higher than that of allografts over 3 years after surgery(P=0.04).In the experimental group,β-TCP degradation was greater in the loose packing treatment than that in the dense packing treatment (P=0.03).Histological observation demonstrated that the process of new bone formation accompanied the degradation of β-TCP.Conclusion The interporous β-TCP could be an advantageous alternative to allografts for repair bone defects caused by bone cyst.The clinical application of β-TCP is safe and reliable,which shows better biodegradation and osteogenesis than allografts in long-term follow-up.
ABSTRACT
To investigate the formation of tissue engineered cartilage using polyglycolic acid (PGA) as three dimensional scaffold seeded with allogenic chondrocytes. First, chondrocytes were harvested from rib cartilage of one week old infant rabbits by collagenase digestion.The isolated cells were cultured in vitro for 2～3 generations, and then the cell suspension was concentrated. Next, the suspension was seeded onto PGA scaffolds soaked with poly l lysine. Then, scaffold chondrocyte constructs were transplanted into subcutaneous tissue of adult rabbits. Finally, the chondrogenesis was studied histologically at various periods. The results showed that chondrocytes were well distributed on the PGA scaffolds in the period of culture in vitro, and could secrete matrix around one week after seeding. 4 weeks after transplantation, the immature cartilage was regenerated in recipient animals. But some inflammatory cells surrounding the new cartilage and some PGA fibers were observed. 8 weeks after transplantation, mature cartilage with abundant matrix was obtained. PGA fibers were not found. This study proves that it is possible to regenerate new cartilage in animals possessing immune function by seeding allogenic chondrocytes onto PGA scaffold. Rejectionreaction is not strong.