股骨頸偏移距離與骨柄遠端固定長度對於髖關節再置換術後穩定度之影響

The influence of femoral neck offset and extent of distal fixation of femoral stem on the stability of postoperative femur in THA revision

洪欣瑋(Hsin-Wei Hung)

指導教授 ： 陳文斌

中原大學/工學院/醫學工程研究所/碩士(2006年)

https://doi.org/10.6840/cycu200600670

摘要

人工髖關節再置換術的目的在於達到術後正常解剖學位置，並儘可能保存病人骨存量。此手術必須先將舊有的股骨柄拔除，而在拔除的過程中極可能造成骨缺損發生，所以在重建上有其一定的困難度。對於這類型的病患，臨床上可用遠端固定法來達到術後穩定度，而許多研究也顯示這樣的固定法確實可達到其術後滿意的效果。
本研究目的為使用有限元素法分析對於骨柄直徑、緊配程度、緊配接觸長度、摩擦係數以及骨頸偏移距離參數做評估比較其對再置換手術術後穩定度的影響，爲了探討方便，分為簡單模型及真實模型。於簡單模型結果可得影響程度依序為：緊配程度>緊配接觸長度>股骨柄直徑>摩擦係數，真實模型為：緊配接觸長度>骨頸偏移距離。 根據分析所設定的限制條件及得到的結果，列出幾點臨床建議：(1)在股骨柄直徑為固定的情況下，緊配接觸長度越長(在本研究為4cm)，術後穩定度越好。(2)於股骨柄直徑大或小均能達到相同的緊配接觸長度的條件下，選擇較小直徑的骨柄(在本研究中為15mm)，可達到較好的穩定度，且可保存骨存量。(3)增加緊配程度，術後穩定度越高。

關鍵字

遠端固定 ； 人工髖關節再置換手術 ； 有限元素法

並列摘要

The goals of revision total hip arthroplasty (revion THA) include reconstruction of the anatomy and reparation of normal biomechanics, and preserve as much bone quality as possible. It probably lead to bone deficiency during the process of removing the loosened femoral stem so that it’s hard to reconstruction. Clinically, the use of distal fixation is good for these patients to reach the initial stability, and many previous studies revealed that such a distal fixation really got up to good stability.

The objective of the current study is to use finite element method to analyze the diameter of the femoral stem, undersized extent, distal fit length, friction coefficient and femoral stem offset, these parameters above were evaluated in effect of revision THA on post-operative stability. The finite element models were separated into simplified and real models. The results of simplified model showed that the undersized extent had the high priority in these affective factors, and other were distal fit length, the diameter of the femoral stem and the friction coefficient in sequence. The results of real model revealed that the distal fit length was priority over the femoral stem offset.

A few clinical suggestions based on our results were listed below:
(1) The longer the distal fit length (the current study is 4 cm) the better the stability on the premise that the diameter of femoral stem is invariable.

(2) The use of the smaller femoral stem (the current study is 15 mm) could reach the better stability and preserve bone quality so much on premise that the equivalent distal fit length were reached whether the larger femoral stem or not.

(3) The larger undersized extent the better the stability.

並列關鍵字

Finite element method ； distal fixation ； revision THA

參考文獻

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