Istituto Ortopedico Rizzoli, University of Bologna, Italy.
Int Orthop. 2010 Dec;34(8):1115-21. doi: 10.1007/s00264-009-0855-5. Epub 2009 Sep 18.
The aim of this study was to evaluate the effects of limb lengthening up to 20 mm after THA on symmetry of hip kinematics and kinetics during common activities of daily living. Twenty patients (age range 49-80 years) operated on with Link Lubinus II THA, with lateral access and a mean follow-up of 16 months, were assessed by gait analysis during level walking, stair ascending and descending. The time-distance, hip kinetics and kinematics values were statistically compared between the operated side and the non-operated side in order to assess symmetry. The 12-item Questionnaire was used to assess satisfaction and personal perception of limb lengthening. Mean value of limb lengthening after THA was 11 mm (SD 6). Minor abnormalities were found in the kinematics and kinetics of the operated and non-operated hips during level walking and stair climbing. The score of the questionnaire corresponded to a high level of satisfaction after THA and only two patients complained of limping independent from the amount of discrepancy. From this study we can conclude that a leg length inequality in the range of 1-20 mm does not impair the symmetry of time-distance parameters and of hip kinematics and kinetics during gait and stairs walking. Although objective, gait analysis data did not correspond to patient's perception of discrepancy, which is subjective and irrespective of the amount of lengthening. There is biomechanical evidence that a limb lengthening of up to two centimetres after THA in general does not need to be corrected by means of a contralateral shoe lift. Individual decisions to the contrary need to be justified.
本研究旨在评估 THA 后肢体延长 20mm 对日常活动中髋关节运动学和动力学对称性的影响。20 例（年龄 49-80 岁）接受 Link Lubinus II THA 手术，采用外侧入路，平均随访 16 个月，通过步态分析评估水平行走、上下楼梯时的步态。为了评估对称性，对手术侧和非手术侧的时间-距离、髋关节动力学和运动学值进行了统计学比较。采用 12 项问卷评估满意度和对肢体延长的个人感知。THA 后肢体延长的平均值为 11mm（SD6）。在水平行走和爬楼梯时，手术侧和非手术侧髋关节的运动学和动力学存在轻微异常。问卷评分对应于 THA 后的高度满意度，只有两名患者抱怨跛行，与差异量无关。从这项研究中我们可以得出结论，在 1-20mm 范围内的腿长不等不会影响步态和上下楼梯时的时间-距离参数和髋关节运动学和动力学的对称性。尽管步态分析数据是客观的，但与患者对差异的感知不相符，患者的感知是主观的，与延长量无关。有生物力学证据表明，THA 后肢体延长达两厘米通常不需要通过对侧鞋跟垫高来纠正。需要证明相反的个别决定是合理的。
