Uhthoff H K, Goto S, Cerckel P H
J Orthop Res. 1987;5(1):14-22. doi: 10.1002/jor.1100050104.
The healing patterns of trabecular bone are different from those of compact bone. In order to investigate further this observation, a histomorphometric assessment was undertaken. The influence of internal fixation devices on trabecular bone healing was also studied. Intercondylar osteotomies were produced in 19 dogs and fixed with screws. All dogs were killed between 1 and 14 weeks; eight of them had the screws removed 4 weeks after osteotomy and were killed 4 or 10 weeks later. The results of morphometry were compared to the histologic and radiologic pictures. Anatomic reduction with stable fixation led to contact healing characterized by a narrow endosteal bone formation at the osteotomy site that disappeared only after union was complete (4 weeks). In gap healing, the endosteal bone formation was greater. Internal fixation devices appeared to cause a diffuse osteopenia once union was complete. Their removal just after completion of union seems to prevent the bone loss. Screws induced bone formation around their threads; after they were removed, the reaction disappeared but the screw holes were not filled with normal trabeculae 10 weeks later. Union of fractures through trabecular bone can be assessed radiologically. A decrease of band-like bone density at the fracture site indicates completion of union. This is the optimal time for implant removal. It prevents the osteopenia observed in cases of continuous presence of screws.
松质骨的愈合模式与密质骨不同。为了进一步研究这一观察结果，进行了组织形态计量学评估。还研究了内固定装置对松质骨愈合的影响。对19只狗进行髁间截骨并用螺钉固定。所有狗在1至14周之间处死；其中8只在截骨后4周取出螺钉，并在4或10周后处死。将形态计量学结果与组织学和放射学图像进行比较。解剖复位并稳定固定导致接触愈合，其特征是截骨部位有狭窄的骨内膜骨形成，仅在完全愈合（4周）后才消失。在间隙愈合中，骨内膜骨形成更多。一旦愈合完成，内固定装置似乎会导致弥漫性骨质减少。在愈合完成后立即取出它们似乎可以防止骨质流失。螺钉在其螺纹周围诱导骨形成；取出螺钉后，反应消失，但10周后螺钉孔未被正常小梁填充。通过松质骨的骨折愈合可以通过放射学评估。骨折部位带状骨密度的降低表明愈合完成。这是取出植入物的最佳时间。它可以防止在螺钉持续存在的情况下观察到的骨质减少。
