Objective:To investigate whether the composite materials of dense nano-hydroxyapatite/polyamide 66(nHA/PA66) wrapped by autologous periosteum and tendon can reconstruct carpal scaphoid. Methods:36 New Zealand white rabbits were randomly divided into three groups

A

B

and C

12 rabbits in each group. Group A:composite material of dense nHA/PA66 wrapped by autologous periosteum and tendon;Group B:composite material of dense nHA/PA66 wrapped by autologous tendon; Group C:autologous tendon ball alone. After bilateral carpal bones were completely removed

the above three materials were respectively implanted to replace radial carpal bone. 3

6

12 weeks aftersurgery

the whole wrist was collected forgross observation

radiological and histological examination

and carpometacarpal index was measured for statistical analysis. Results:In Group A

3 and 6 weeks after surgery

a small amount of chondroblasts were found on the surface of the composite material of nHA/PA66;12 weeks after surgery

chondroblasts increased and hyaline-like cartilage formed around the material. The composite materials of nHA/PA66 were combined more closely with soft tissue around by the fibers at the twelfth week than that at the third or the sixth week. During different time periods

no composite materials of nHA/PA66 were fragmented

absorbed or degraded. In Group B and C

no transparent cartilage was found around the implants during different periods

but the gross observation and radiological examination showed that the cartilage in wrists lost obviously and the wrists collapsed significantly in Group C

as compared with those in Group A and B. The statistical analysis showed carpometacarpal indexes in group A and B were not significantly lower(P>0. 05)

while that in group C was significantly lower(P<0.01).Conclusion:That autologous periosteum and tendon wrapping densenHA/PA66 could form composite materials in the wrist joint cavity;hyaline-like cartilage could form on their surface

and the materials were so strong that they could be used to replace scaphoid bones .