强直性脊柱炎股骨形态及全髋置换术后的股骨假体分析

The morphology of femur in AS patients and their femoral prothesis analysis after total hip arthroplasty

目的探讨强直性脊柱炎患者行全髋关节置换术时的假体选择方法。方法将24例(36髋)强直性脊柱炎患者设为强直性脊柱炎(AS)组,所有纳入患者术前均已出现关节强直,并进行了非骨水泥人工全髋关节置换术。对照组共30例(45髋),均系非强直性脊柱炎患者并且进行非骨水泥型全髋关节置换术。分析两组患者术前髋关节正侧位片,并且测量singh指数、髓腔张开指数、皮质形态指数和皮质骨指数,分析两组患者术后X线片,测量股骨假体的髓腔占有率,进行组间计量资料t检验,对髓腔占有率和Singh指数进行Spearman等级相关分析。结果两组间在singh指数、髓腔张开指数、皮质形态指数以及假体髓腔占有率方面存在显著性差异(P<0.05)。皮质骨指数两组间无统计学差异(P>0.05)。强直性脊柱炎患者的股骨近段出现比较显著的骨质疏松以及形态学改变,髓腔形态更接近于直立,髓腔开口处张口角度更大,骨皮质变薄。结论在没有定制型假体的情况下,对于由于强直性脊柱炎严重骨质疏松所造成的股骨近段髓腔形态呈现烟囱型改变的患者,应该选用传统水泥型假体并按照关节翻修术的方法来处理;对于髓腔形态没有出现显著改变的强直性脊柱炎患者仍可选用传统生物固定型假体;根据患者髓腔形态利用CAD技术特殊设计的个体化水泥型假体应比现有类型假体更加适合强直性脊柱炎患者。

Objective To investigate the morphological changes of the proximal femur for femoral prosthesis selection in total hip replacement of ankylosing spondylitis （AS） . Methods Twenty-four patients （36 hips） admitted for cementless THR because of AS were enrolled in this study, thirty patients （45 hips） without AS werein the control group. The Singh index, canal flare index, morphological index of the cortex, cortical index and stem-canal fit were measured in the two groups on the basis of roentgenograms. All the data was analyzed by statistics. Results There were significant differences between the two groups in Singh index, canal flare index, morphological index of the cortex and stem-canal fit （ P 〈 0. 05）, but not in the cortical index （ P 〉 0. 05） . The AS patients were found to have severe osteoporosis in the upper femur and massive spongy bone loss, so that the morphology of the canal was almost orthostatic in the upper femur because the thin femoral cortex. Conclusions Cemented prosthesis was recommended for AS patients with severe osteoporosis, who should be treated as revised THR to ensure good fit of the prosthesis to the canal. Cementless prosthesis, however, can still achieve good curative effect in AS patients without significant morphologic changes in the proximal femurs. Computer-aided design and manufacture of individualized prosthesis will be more suitable for the AS patients than the currently available prosthesis.