摘要
目的探讨全髋关节置换术后髋关节前屈后伸活动范围的计算方法。方法1、用数学方法推导人工全髋关节前曲和后伸时股骨假体柄上臼柄撞击点位置的数学表达式:(1)设股骨假体前倾角a,股骨假体颈干角的补角的余角J,股骨假体颈柄的半径为L。(2)通过函数求导数的方法确定股骨假体柄上头颈结合圆上距矢状面距离最小点位置。(3)人工髋关节前曲和后伸时股骨假体柄上臼柄撞击点位于头颈结合截面圆上距该圆圆心距离h=L(1-sin2a)/(1+sin2a)的水平弦与圆在后方的交点。2、求出人工髋关节屈伸活动时臼柄撞击点所具有的外展角或前倾角b=arcsin[cosa2k2-2-2(1+sin2a)]/2k(k为头颈比)。3、根据髋臼外展角和前倾角动态变化规律得出全髋关节置换术后髋关节前屈后伸活动范围数学表达式。结果全髋关节置换术后髋关节前屈后伸活动范围ROM=180°-arcsin[tg2Atg2B-(tg2A+tg2B)(tg2b-tg2A)-tgAtgB]/(tg2A+tg2B)-arcsin[tg2Atg2B-(tg2A+tg2B)(tg2b-tg2B)-tgAtgB]/(tg2A+tg2B)(A和B分别为髋臼杯前倾角和外展角)。结论全髋关节置换术后髋关节前屈后伸活动范围与头颈比呈正相关,与股骨假体颈前倾角呈负相关。髋臼杯外展角与后伸活动度正相关与前屈活动度呈负相关、髋臼杯前倾角与后伸活动度负相关与前屈活动度呈正相关,该公式准确、可靠,值得临床参考。
Objective To explore the calculated methods of hip range of flexion and extension after total hip joint replacement. Methods 1. The mathematical expression of acetabulun-stem impingement point on prosthetic femoral stem when flexion and extension of hip joint was derived by mathematical methods： （1） Supposing the femoral prosthesis anteversion was a, the complementary angle of the femoral prosthesis neck-stem angle supplementary angle was J, the femoral prosthesis stem radius was L. （2） Determining the position of the point where the distance between this point and the sagittal plane was the nearest on the circle connecting prothsitic femoral head and neck by taking function derivative. （3） The impingement point on the circle connecting prothsitic femoral head and neck when hip flexion and ex- . . . 2 2 tension was the intersection point formed by the circle and the level chord which distances h=L√（1-sin^2 a）/（1＋sin^2 a） from the chord to the circle center. 2. The abduction or anteversion b of acetabulnn-stem impingement point on prosthetic femoral stem when hip flexion and extension was found： b=arcsin[cosa√2k^2-2- √2（1＋sin^2a） ]/2k （k was Head-Neck Ratio）. 3 The mathematical expression of flexion and extension ROM after total hip replacement was brought offby referring dynamical variety law of aeetabular abduction and anteversion. Results ROM of flexion and extension after total hip replacement was 180°-arcsin [√tg^2Atg^2B-（tg^2A＋tg^2B）（tg^2b-tg^2A）-tgAtgB]/（tg^2A＋tg^2B）-arcsin[√tg^2Atg^2B-（tg^2A＋tg^2B）（tg^2b-tg^2B）-tgAtgB]/（tg^2A＋tg^2B（A and B was anteversion and abduction of acetabulum-cup）. Conclusion The artificial hip range of flexion and extension after total hip replacement was negatively correlated with artificial femoral neck antev- ersion and positively correlated with head-neck ratio. Cetabulum-cup abduction was positively con＇elated with extense rang and negatively correlated with anteflex rang, cetabulum-cup anteversion was positively correlated with anteflex rang and negatively correlated with extense rang. The calculating formula was accurate and reliable and worthy of clinical reference.
出处
《临床医学工程》
2010年第2期4-6,共3页
Clinical Medicine & Engineering
关键词
髋关节
置换
前屈
后伸
活动范围
Hip
Replacement
Flexion
Extension
Range of activities
