The Effects of Pin Fixation and Intramedullary Rod Penetration on the Rabbit Distal Femoral Epiphyses

The effects of fixation device on the growth plate is crucial in pediatric orthopaed-ics practice. Though some studies were reported, the detail mechanisms of pin fixation on the growth late were not clear. Present report studied the pin fixation effects on the distal femoral growth plate of immature rabbits. Four animal groups were de-signed : Group A: distal femoral epiphyseal plate was drilled by two cross smooth pins (1.2 mm Kirschner’s wires) percutaneously. Group B: same as Group A but with the pin in situ. Group C: a Large gauge intramedullary rod (3.2 mm steinman’s pin) was drilled across the center of the distal femoral epiphyseal plate through intercondylar area. Group D: done as Group C, butwith the rod retained in place. The observation periods were one, two, and three months postoperatively . Both roentgenographic measurement and histological examination were done. Totally 27 rabbits went through the experiment. Results showed that Group B had greatest growth retardation which was statistic-cally significant than the other three groups (P ＜ 0.05). Group A was almost normal except the small pin entrance and tract region. Group Chad bony bridge within the pin tract, and mild longitudinal growth retardation. Group D was found with disar- rangement of chondrocyte columns and little retardation of longitudinal growth . The results suggest that the cross pin fixation through the growth plate in the surger-ies should be removed as early as possible, if the fraceture become stable. The in-tramedullary rod should be used carefully but its adverse effect is less than cross pin fixation in the rabbit model.

並列關鍵字

Growth plate ； Histology ； Cross pin fixation ； Intramedullary rod

國際替代計量

全文下載

主題瀏覽