Chu Stacey R, Boyer Elizabeth H, Beynnon Bruce, Segal Neil A
Carver College of Medicine, The University of Iowa, Iowa City, Iowa.
Department of Kinesiology, Iowa State University, Ames, Iowa.
PM R. 2019 Feb;11(2):117-124. doi: 10.1016/j.pmrj.2018.06.012. Epub 2019 Feb 14.
Altered joint laxity can contribute to joint dysfunction. Knee joint laxity has been shown to increase during pregnancy, but its long-term persistence is unknown.
To determine whether pregnancy leads to lasting increases in knee joint compliance and laxity that persist longer than 4 months postpartum.
Prospective cohort study.
A motion analysis laboratory at an academic medical center.
Fifty healthy women in their first trimester of pregnancy (mean ± SD 29.2 ± 4.3 years old and baseline body mass index 26.0 ± 5.4 kg/m ) were recruited.
End-range knee laxity and midrange joint compliance were measured during the first trimester and 19 ± 4 weeks postpartum. Anterior-posterior and varus-valgus laxity were measured using 3-dimensional motion tracking while applying forces and moments in each respective plane using the Vermont Knee Laxity Device. Nonlinear models were constructed to assess relations between applied forces and joint translation, comparing early pregnancy with postpartum.
Multiplanar knee laxity and compliance.
Peak varus-valgus (20-22%; P = .001) and posterior translation (51%; P < .001) of the tibia relative to the femur decreased from baseline, with a concomitant decrease in laxity (P < .001) and compliance (P = .039) in the coronal plane and in the posterior direction in primiparous (P = .009) and multiparous (P = .014) women. For primiparous women, laxity (P < .001) and compliance (P = .009) increased in the anterior direction.
Pregnancy resulted in a lasting decrease in multiplanar knee laxity and compliance in the varus and posterior directions with an increase in anterior compliance. The effects of these changes in laxity and compliance of the passive stabilizers on knee loading patterns, articular contact stresses, and risk for osteoarthritis and other musculoskeletal disorders will require additional research.
II.
关节松弛度改变可导致关节功能障碍。研究表明，孕期膝关节松弛度会增加，但其长期持续性尚不清楚。
确定妊娠是否会导致膝关节顺应性和松弛度持续增加，且这种增加在产后4个月以上仍持续存在。
前瞻性队列研究。
一所学术医疗中心的运动分析实验室。
招募了50名处于妊娠早期的健康女性（平均年龄±标准差为29.2±4.3岁，基线体重指数为26.0±5.4kg/m²）。
在妊娠早期和产后19±4周测量膝关节终末松弛度和中间范围关节顺应性。使用三维运动跟踪技术，在使用佛蒙特膝关节松弛度测量仪在各个平面施加力和力矩时，测量前后和内外侧松弛度。构建非线性模型，评估施加力与关节平移之间的关系，比较妊娠早期与产后情况。
多平面膝关节松弛度和顺应性。
相对于股骨，胫骨的最大内外侧（20 - 22%；P = 0.001）和后向平移（51%；P < 0.001）从基线水平下降，同时初产妇（P = 0.009）和经产妇（P = 0.014）在冠状面和后向方向的松弛度（P < 0.001）和顺应性（P = 0.039）也随之降低。对于初产妇，前向方向的松弛度（P < 0.001）和顺应性（P = 0.009）增加。
妊娠导致多平面膝关节在内外侧和后向方向的松弛度和顺应性持续降低，前向顺应性增加。这些被动稳定器的松弛度和顺应性变化对膝关节负荷模式、关节接触应力以及骨关节炎和其他肌肉骨骼疾病风险的影响，还需要进一步研究。
II级。
