摘要
目的通过在体外测量方式测定骨外固定器的轴向载荷与患者体重的分担比例来评价骨愈合程度，探讨骨外固定器的安全拆除时机。方法在体外模拟实验中，用经过处理后的人体胫骨制造胫骨横行骨折模型，在骨外固定器上轴向并联安装拉压力学信息采集系统。利用不同软硬的材料来模拟骨断端由腔隙血肿直到骨痂硬化不同阶段的骨痂。将装有骨外固定器的胫骨远、近端放置于BOSE3510机械性能测试系统中并于骨端施加轴向压力70kg。收集2013年9月至2016年3月用骨外固定器治疗的患者21例，胫腓骨19例，股骨2例；骨折20例，骨延长1例；开放性骨折16例，骨折并感染4例，骨缺损2例。根据不同的骨愈合阶段，患者采用不同的负重情况测量其骨外固定器的载荷分担比变化。骨折愈合后期（拆外固定器前）测量患者完全负重情况下骨外固定器载荷分担比并结合临床表现及X线片判断安全拆除时机。结果通过模拟实验得出线性方程：y=0．243x-564．882（“x”代表传感器的数值，“y”代表载荷值）。各材料可以模拟骨折愈合过程中骨痂不同阶段硬化程度，并且可以通过比较载荷分担比来反映骨痂的硬化程度：皮质骨〉骨水泥〉松质骨〉木板〉塑铝〉纸墙〉石膏。21例患者中，18例患者的骨外固定器载荷分担比〈10％，拆除外固定器后均无再骨折等并发症发生；3例患者骨外固定器载荷分担比〉10％，其中1例患者拆除骨外固定器后发生再骨折，其余2例未予拆除骨外固定器，继续随诊观察。结论依据骨外固定器轴向载荷分担比评价骨痂愈合刚度，以确定骨外固定器拆除的安全性，可以有效降低骨痂愈合相关并发症（如再骨折）的发生率。当骨外固定器轴向载荷分担比〈10％时拆除外固定器较安全、可靠。
Objective To create a credible quantitative method to evaluate callus＇s stiffness which can be used to judge appropriate time to remove external skeletal fixator safely. Methods Firstly, a model of tibial transverse fracture was built to determine the relationship between callus stiffness and loading on the external skeletal fixator on which pressure sensors and data collecting system were installed. The space between bone ends was imbedded respectively with materials with various degrees of stiffness to simulate the process of callus developing from hematoma to sclerosis. The whole unit was tested on the biomechanical test system BOSE 3510, with an axial load of 70 kg. Secondly, medical records of 21 patients were collected who had been treated by external skeletal fixation from September 2013 to March 2016, involving the tibia and fibula in 19 cases and the femur in 2. Twenty cases underwent treatment of fracture and one bone lengthening. Open fractures were treated in 16 cases, fracture and infection in 4 and bone defects in 2. In the different process of bone healing, changes in load-share ratio of external fixation were measured with different axial loading. Before removal of the external skeletal fixation, the load-share ratio of external fixation with full loading was measured to determine the appropriate time to remove the external skeletal fixator on the basis of the patients＇ clinical situation and X-ray plain films. Results A linear equation resulted from the sim- ulative experiment： y = 0. 243 x - 564. 882, with x representing the reading of pressure sensor and y repre- senting loading value. The varying bone callus＇s stiffness during the fracture healing process could be simulated by different materials. The axial load-share ratios were relevant to the callus stiffness. No suchcomplications us re-fracture happened alter removal of the external fixalion in 18 patients who had a load-share ratio 〈 10% . Of Ihe other 3 patients who had a load-share ratio 〉 10%, one had re-fraeture after removal of external fixation and 2 had to sustain eontinuoas treatment and follow-up without removal of the ex- ternal fixation. Conclusions The axial load-share ratio may be an appropriate indicator in evaluation of the bone callus sliffness, h can be used to judge appropriate time to remove external skeletal fixator safely so as to effectively reduce the complications related to callus＇s healing. It may be sate to remove the external skeletal fixation when the load-share ratio is 〈 10%.
出处
《中华创伤骨科杂志》
CAS
CSCD
北大核心
2016年第12期1050-1056,共7页
Chinese Journal of Orthopaedic Trauma
关键词
外固定器
骨痂
骨折愈合
载荷分担比
安全拆除时机
Exlernal fixators
Bony callus
Fraclure healing
Load-share ralio
Safe re-moval time
