BACKGROUND: Treatment of large bone defects is an important problem faced by orthopedic physicians. Allogeneic bone transplantation is a classic method, but it has many restrictions. The membrane guided bone regeneration technique has become an important method for the research nowadays.OBJECTIVE:To compare the effects of self-made high strength biodegradable nano-hydroxyapatite/multi(amino acid) copolymer (n-HA/MACP) guided bone regeneration membrane tube and allograft bone graft segment in the repair of large segmental bone defect in goats. METHODS: The model of 30 mm large segment bone defect in the middle section of the femur in 32 adult goats was established. Experimental group used self-made n-HA/MACP tube to bridge defects following bone plate fixation. The control group was treated with allograft bone graft bone segments combined with plate fixation. The animals were sacrificed at 4, 8, 12 and 16 weeks after operation, and the bone callus growth was observed in the specimens. The X-ray and histological observations were performed at the same time. Biomechanical measurement of plate fixation of allograft cortical bone segment was done at 12 and 16 weeks after operation. RESULTS AND CONCLUSION: (1) After 4 to 16 weeks, gross and pathological results showed fibrous callus growth inside and outside of the membrane tube, and the fibrous callus gradually hardened into a bony callus. Additionally, the callus was larger in the experimental group than in the control group. X-ray films showed significantly increased lateral callus density in the experimental group as compared with the control group. (2) Maximum bending strength was significantly higher in the experimental group than in the control group at 16 weeks (P < 0.05). Overall, the n-HA/MACP membrane tube used for bridging large segment bone defects in goats can obtain similar repair effects to the allograft cortical bone, and further achieve the better mechanical strength of the new bone segment than the allograft bone.

BACKGROUND:Bisphosphonates that can suppress osteoclast activity strongly is a powerful inhibitor for bone resorption, which has been reported to have good effects in the treatment of fibrous dysplasia.
OBJECTIVE:To evaluate the clinical effect of surgical treatment combined with bisphosphonate therapy in the treatment of fibrous dysplasia.
METHODS: Fifteen patients with fibrous dysplasia of the long bone were subjected to surgical treatment and oral bisphosphonate therapy postoperatively. Limb pain, limb function, local X-ray manifestations and blood alkaline phosphatase activity were observed before and at 3, 6, 12, 24 months after treatment. The therapeutic effects were evaluated using modified Macnab standards.
RESULTS AND CONCLUSION:Al the 15 patients were folowed up for more than 24 months, and their pain symptoms were significantly relieved after the combined treatment of surgery and bisphosphonates, excelent in 12 cases and effective in 1 case, and the total efficiency was 100%. X-ray films showed that the density slightly decreased in operation areas after 3 months, but at 6 months after treatment, the cortical bone was thickened and the marrow cavity density increased in the operation areas, and non-focal zone was continuously enlarged. No fractures and recurrence were found in al patients. At 6 months after treatment, the serum alkaline phosphatase activity decreased significantly (P < 0.05). The results suggest that surgical operation with bisphosphonate treatment for bone fibrous dysplasia can effectively inhibit the bone resorption, promote bone formation, increase the intensity of the lesion, reduce fractures and recurrence rate, so as to achieve a better therapeutic effect in clinic.

Obej ctive Knockout mice are widely used in the studies of joint diseases .This article investigated the effects of joint processing methods , collagenase types ,and collagenase digestion time on the number of primary fibroblast -like synoviocytes (FLSs) obtained from mice. Methods The hind legs of 6 of the 12 male mice were cut open from the hip joints , but not those of the other 6.FLSs were isolated using the type-Ⅳcollagenase digestion method and purified by differential digestion .Cell morphology was observed under the inverted microscope .The type, viability, and purity of the cells were determined by flow cytometry . Rse ults Significantly fewer FLSs were obtained from the mice with the hind legs cut open ( 19 133 ±115 ) than from those without (24 933 ± 503) (P<0.05).The numbers of FLSs collected from the cell suspension at 1, 2, 3, 4, 5,6 , and 7 hours after digestion were 700 ±300 , 600 ±100 , 15 200 ±900 , 5100 ±800 ,2700 ±300 , 900 ±200, and 300 ±100, respectively, the highest at 3 hours. There were statistically significant differences in the total number of FLSs obtained by type-Ⅳ and type-Ⅱ collagenase digestions (24900 ±500v s 18 100 ±400, P<0.05). Conclusion For in virt o culture of primary mouse FLSs, it is recommended that the hip joints be not cut open, and type-Ⅳcollagenase be used with cell sus-pension at 2-6hours after digestion .