Spring Loaded Technology Inc., 50 Raddall Avenue, Unit 8, Burnside, NS B3B 1T2, Canada.
J Biomech Eng. 2020 Jan 1;142(1). doi: 10.1115/1.4044818.
Knee osteoarthritis (OA) is a significant problem in the aging population, causing pain, impaired mobility, and decreased quality of life. Conservative treatment methods are necessary to reduce rapidly increasing rates of knee joint surgery. Recommended strategies include weight loss and knee bracing to unload knee joint forces. Although weight loss can be beneficial for joint unloading, knee OA patients often find it difficult to lose weight or begin exercise due to knee pain, and not all patients are overweight. Unicompartment offloader knee braces can redistribute joint forces away from one tibiofemoral (TF) compartment; however, <5% of patients have unicompartmental tibiofemoral osteoarthritis (TFOA), while patients with isolated patellofemoral or multicompartmental OA are much more common. By absorbing body weight (BW) and assisting the knee extension moment using a spring-loaded hinge, sufficiently powerful knee-extension-assist (KEA) braces could be useful for unloading the whole knee. This paper (1) describes the design of a spring-loaded tricompartment unloader (TCU) knee brace intended to provide unloading in all three compartments of the knee while weight-bearing, (2) measures and compares the force output of the TCU against the only published and commercially available KEA brace, and (3) calculates the static unloading capacity of each device. The TCU and KEA braces delivered maximum assistive moments equivalent to reducing BW by approximately 45 and 6 lbs, respectively. The paper concludes that sufficiently powerful spring-loaded knee braces show promise in a new class of multicompartment unloader knee orthoses, capable of providing a clinically meaningful unloading effect across all three knee compartments.
膝骨关节炎（OA）是老龄化人口中的一个重大问题，会导致疼痛、活动受限和生活质量下降。为了降低膝关节手术的快速增长，需要采用保守的治疗方法。推荐的策略包括减轻体重和膝关节支具以减轻膝关节的受力。虽然减轻体重对关节减压有益，但由于膝关节疼痛，OA 患者往往难以减肥或开始运动，而且并非所有患者都超重。单室膝关节减压器支具可以将关节力从一个胫股（TF）间室重新分配；然而，只有<5%的患者患有单室胫股关节炎（TFOA），而患有孤立髌股或多室 OA 的患者则更为常见。通过吸收体重（BW）和使用弹簧加载铰链辅助膝关节伸展力矩，足够强大的膝关节伸展辅助（KEA）支具可能有助于减轻整个膝关节的负荷。本文（1）描述了一种弹簧加载的三室减压器（TCU）膝关节支具的设计，旨在提供在承重时减轻膝关节三个间室负荷的能力，（2）测量并比较了 TCU 与唯一已发表和市售的 KEA 支具的力输出，（3）计算了每个装置的静态卸载能力。TCU 和 KEA 支具提供的最大辅助力矩相当于分别减轻 BW 约 45 磅和 6 磅。本文得出结论，足够强大的弹簧加载膝关节支具在一种新型的多室减压器膝关节矫形器中显示出了希望，能够在所有三个膝关节间室提供有临床意义的减压效果。
