股骨近端L型截骨術之三維有限元素分析

Three-Dimensional Finite Element Analysis of the L-type Osteotomy in the Proximal Femur

高富群(Fu-Chun Kao)

指導教授 ： 陳文斌

中原大學/工學院/醫學工程研究所/碩士(2004年)

https://doi.org/10.6840/cycu200400656

摘要

股骨殘餘變形向來是先天性股骨頭滑脫、Perthes氏疾病及細菌性關節炎治療後，最為嚴重的併發症之一。其特徵包含股骨頸過短、大轉子發育過大及下肢長短不一等髖關節之崎型發育。Papavasiliou等人曾經針對十六名患有髖關節殘餘變形之患者施以L型股骨近端截骨術，經術後臨床追蹤證實效果良好。此一手術法，不僅使得大轉子回歸正常位置，且術後下肢長短一致；此外，更由於術後股骨頸之延長及股骨球頭更深入髖臼，大幅提高髖關節術後之穩定性。
本研究之目的，乃是以三維有限元素法評估L型截骨術術後股骨之力學表現。採用的方法，是以左側股骨患有殘餘變形之病患，利用其電腦斷層影像，以四種不同截骨深度配以四種不同數量之骨螺釘固定做為比較參數，並以同一病患之健康右側股骨幾何形狀作為手術矯正之依據，分別建立有限元素模型。在單腳站立情況下，分析比較上述不同的截骨條件術後股骨蒙麥斯應力與股骨球頭位移量之差異。
結果顯示：植入骨螺釘數量多寡對於股骨之應力分佈並無顯著差異。但是植入較多之骨螺釘數則可得到較少之球頭位移量，進而提高術後股骨穩定性。此外，在骨螺釘總數量相同的情況下，則以股骨板上端骨螺釘之效果優於股骨板下端。而在截骨深度方面，截入深度越深，對於術後股骨之高應力分佈越廣、位移量越大，將降低術後股骨之穩定性。

關鍵字

殘餘變形 ； 有限元素分析 ； L型截骨術

並列摘要

Residual deformity of the femoral is one of the most devastating complications that can arise in the treatment of congential hip dislocation, Perthes disease, or septic arthritis. The femoral neck remains short with a marked relative overgrowth of the greater trochanter, impingement, and shortening of the entire limb. For the reconstruction of residual deformities of the hip, Papavasiliou et al. had performed a new type of proximal femoral L-osteotomy in sixteen patients with residual deformity of the hip. They claimed that the clinical and radiologic followup showed good results in all the patients. The surgical procedure not only provided limb equalization but also repositioned the greater trochanter to its normal level. Another advantage of the L-osteotomy operation was provided by the reorientation of the femoral head deeper into the acetabulum, which improved the contact between the articular surfaces.
The purpose of this study was to use three-dimensional finite element analyses to evaluate the mechanical behavior of the joint after L-osteotomy. A patient with residual deformity of left femur was recruited. By using the computed tomography scan images of the specific deform femur, 3-D finite element models with four different levels of longitudinal osteotomy length together with four different numbers of fixation screws were created. The geometry of the relative right healthy femur of the same patient was considered as the corrective configuration after surgery. Analysis was performed on a loading condition simulating single-legged stance. The von Mises stress distributions and displacements of the femoral head of each model were analyzed and compared.
The results revealed no obvious difference of stress distribution was found among models with different number of fixation screws. However, with regard to the displacement of femoral head, the more the number of the fixation screws, the less the displacement of femoral head, which led to the more stable of the postoperative hip joint. Besides, superior implantation of fixation screw was more effective to stabilize postoperative construct as compared to that of inferior implantation due to the decrease of femoral head displacement. Moreover, high local stress concentration combined with large displacement was found for femur with large longitudinal osteotomized length, which led to an unstable situation for the postoperative femur.

並列關鍵字

L-osteotomy ； Finite element analysis ； Residual Deformity

參考文獻

20.羅世瑋（2002），缺血性壞死股骨頭轉骨術之三維有限元素模擬，中原大學醫學工程研究所碩士論文。

1. Papavasiliou VA, Kirkos JM. Reconstruction of residual deformities of hip. Clin Orthop 341：123-127, 1997

2. Delp SL, Maloney W. Effects of hip center location on the moment-ge- nerating capacity of the muscles. J Biomech 26：485-499, 1993

4. Millis MB, Murphy SB, Poss R. Osteotomies about the hip for the prevention and treatment of osteoarthritis. J Bone Joint Surg 77A：626-647, 1995.

5. Bombelli R. Osteoarthritis of the hip, 2nd ed. Berlin：Springer-Verlag, 1983