Abstract:

BACKGROUND: Selection of optimal substitute to fill the gaps following lunar bone enucleation plays a key role in maintaining biomechanical properties and good wrist joint function.
OBJECTIVE: To study bone-forming mechanism of transplantation autologous periosteum-wrapped tendon, spongiosa homogenate and recombinant human bone morphogenetic protein-2 (rhBMP-2) in joint cavity, and to explore the possibility of the compound as a substitute for the lunar bone.  
METHODS: Forty-five New Zealand white rabbits were randomly divided into three groups: periosteum group, rhBMP-2 group and control group. The three sorts of implants were placed into articular cavity of the knee respectively. The changes of bone formation and rhBMP-2 distribution of the implants were examined under optical microscope with hematoxylin-eosin staining and immunohistochemical staining and measured by CT at 3, 6 and 9 weeks after operation. 
RESULTS AND CONCLUSION: The result of rhBMP-2 staining was negative after 3 weeks and positive in new cartilage cells after 9 weeks in periosteum group. The strong positive rhBMP-2 staining was observed in the composite group at 9 weeks, which mainly distributed in new bone cells and cartilage cells. And negative rhBMP-2 staining was observed every stage in control group. The quantitative CT bone mineral density values of 3 implants were analyzed, the difference was significant between the groups (P < 0.01), except that between periosteum group and control group at 3 weeks (P > 0.05). The above results demonstrated that the compound of autologous periosteum-wrapped tendon and spongiosa homogenate can produce bone and cartilage massively under the induction of periosteum and bone forming factors, such as rhBMP-2 in spongiosa homogenate and the compound can be considered as a preferred substitute to reconstruct lunate bone.