School of Mechanical Engineering, Tianjin University, Tianjin, China.
Department of Radiotherapy, Anhui No.2 Provincial People's Hospital, Hefei, Anhui, China.
BMC Musculoskelet Disord. 2024 May 9;25(1):353. doi: 10.1186/s12891-024-07440-y.
External fixation is widely used in the treatment of traumatic fractures; however, orthopedic surgeons encounter challenges in deciding the optimal time for fixator removal. The axial load-share ratio (LS) of the fixator is a quantitative index to evaluate the stiffness of callus healing. This paper introduces an innovative method for measuring the LS and assesses the method's feasibility and efficacy. Based on a novel hexapod LS-measurement system, the proposed method is to improve the convenience and precision of measuring LS in vivo, hence facilitating the safe removal of external fixators.
A novel hexapod system is introduced, including its composition, theoretical model, and method for LS measurement. We conducted a retrospective study on 82 patients with tibial fractures treated by the Taylor Spatial Frame in our hospital from September 2018 to June 2020, of which 35 took LS measurements with our novel method (Group I), and 47 were with the traditional method (Group II). The external fixator was removed when the measurement outcome (LS < 10%) was consistent with the surgeon's diagnosis based on the clinical and radiological assessment (bone union achieved).
No significant difference was found in the fracture healing time (mean 25.3 weeks vs. 24.9 weeks, P > 0.05), frame-wearing duration (mean 25.5 weeks vs. 25.8 weeks, P > 0.05), or LS measurement frequency (mean 1.1 times vs. 1.2 times, P > 0.05). The measurement system installation time in Group I was significantly shorter compared to Group II (mean 14.8 min vs. 81.3 min, P < 0.001). The LS value of the first measurement in Group I was lower than that of Group II (mean 5.1% vs. 6.9%, P = 0.011). In Group I, the refracture rate was 0, but in Group II it was 4.3% (2/47, P > 0.05).
The novel hexapod LS-measurement system and involved method demonstrated enhanced convenience and precision in measuring the LS of the external fixator in vivo. The LS measurement indicates the callus stiffness of fracture healing, and is applicable to evaluate the safety of removing the fixator. Consequently, it is highly recommended for widespread adoption in clinical practice.
外固定器广泛应用于创伤性骨折的治疗，但骨科医生在确定固定器去除的最佳时间时会遇到挑战。固定器的轴向负荷分担比（LS）是评估愈合力的定量指标。本文介绍了一种测量 LS 的创新方法，并评估了该方法的可行性和效果。基于新型六足 LS 测量系统，该方法旨在提高活体测量 LS 的便利性和精度，从而安全去除外固定器。
介绍了一种新型六足系统，包括其组成、理论模型和 LS 测量方法。我们对 2018 年 9 月至 2020 年 6 月我院收治的 82 例采用 Taylor 空间框架治疗的胫骨骨折患者进行了回顾性研究，其中 35 例采用我们的新型方法进行 LS 测量（I 组），47 例采用传统方法（II 组）。当测量结果（LS<10%）与基于临床和影像学评估的外科医生诊断一致（骨愈合）时，去除外固定器。
两组骨折愈合时间（平均 25.3 周 vs. 24.9 周，P>0.05）、外固定器佩戴时间（平均 25.5 周 vs. 25.8 周，P>0.05）或 LS 测量频率（平均 1.1 次 vs. 1.2 次，P>0.05）无显著差异。I 组安装测量系统的时间明显短于 II 组（平均 14.8 分钟 vs. 81.3 分钟，P<0.001）。I 组第一次测量的 LS 值低于 II 组（平均 5.1% vs. 6.9%，P=0.011）。I 组再骨折率为 0%，而 II 组为 4.3%（2/47，P>0.05）。
新型六足 LS 测量系统及相关方法在活体测量外固定器 LS 方面具有更高的便利性和精度。LS 测量反映了骨折愈合的骨痂刚度，适用于评估去除固定器的安全性。因此，强烈建议在临床实践中广泛应用。
