Ito Hideyuki, Amano Tetsuya, Ichihara Kiyoshi
Department of Rehabilitation, Faculty of Wakayama Health Care Science, Takarazuka University of Medical and Health Care, 2252 Nakanoshima, Wakayama, Wakayama-Pref.640-8392, Japan.
Department of Physical Therapy, Faculty of Health and Medical Sciences, Tokoha University, Hamamatsu, Japan.
BMC Sports Sci Med Rehabil. 2024 May 18;16(1):113. doi: 10.1186/s13102-024-00901-w.
Reference values (RVs) for knee function tests have been reported in perioperative patients with knee osteoarthritis (KOA); however, such values for practical use in outpatient setting has yet to be determined. Therefore, we aimed to establish the reference intervals (RIs) for outpatients with mild to moderate KOA.
This cross-sectional study enrolled 202 outpatients with KOA from 8 Japanese orthopedic clinics and measured knee extensor/flexor muscle strength (MS) and knee extension/flexion range of motion (ROM). We used multiple regression analysis to evaluate the sources of variation, including sex, age, body mass index, Kellgren-Lawrence (K-L) classification, bilateral KOA, and exercise habits. Magnitude of between-subgroup differences is expressed as standard deviation ratio (SDR) based on a three-level nested analysis of variance, with SDR ≥ 0.4 as the threshold for requiring RIs specific for subgroups. RIs were calculated parametrically using two-parameter Box-Cox formula if Gaussian transformation of RVs was successful, otherwise calculated nonparametrically.
Partitioning was required by sex for extensor and flexor MS (SDR = 0.65, 0.57, respectively) and by K-L classification for flexion ROM (SDR = 0.54). RIs were determined parametrically for extensor MS as 0.27-2.09 (male) and 0.27-1.54 (female) Nm/kg and for flexor MS 0.18-1.20 (male) and 0.13-0.79 (female) Nm/kg. On the other hand, RIs for extension and flexion ROM were determined nonparametrically due to discrete nature of their RVs. The RIs determined for extension ROM were -15°-0° and for flexion ROM were 105°-150° (for K-L grade I/II) and 95°-140° (for K-L grade III/IV).
The ranges of RIs determined specifically for patients with mild to moderate KOA were in-between those of age-matched healthy controls and pre-surgical KOA patients, both of which we had reported for use in physiotherapeutic management of KOA patients undergone total knee arthroplasty. The newly derived RIs will provide an objective benchmark for physiotherapy targeting outpatients with mild to moderate KOA.
膝关节骨关节炎（KOA）围手术期患者膝关节功能测试的参考值（RVs）已有报道；然而，在门诊环境中实际使用的此类值尚未确定。因此，我们旨在确定轻度至中度KOA门诊患者的参考区间（RIs）。
这项横断面研究纳入了来自8家日本骨科诊所的202例KOA门诊患者，测量了膝关节伸肌/屈肌力量（MS）和膝关节伸展/屈曲活动范围（ROM）。我们使用多元回归分析来评估变异来源，包括性别、年龄、体重指数、凯尔格伦-劳伦斯（K-L）分级、双侧KOA和运动习惯。基于三级嵌套方差分析，亚组间差异的大小以标准差比（SDR）表示，SDR≥0.4作为需要特定亚组RIs的阈值。如果RVs的高斯变换成功，则使用双参数Box-Cox公式参数化计算RIs，否则进行非参数计算。
伸肌和屈肌MS按性别划分（SDR分别为0.65和0.57），屈曲ROM按K-L分级划分（SDR为0.54）。伸肌MS的RIs参数化确定为男性0.27 - 2.09 Nm/kg，女性0.27 - 1.54 Nm/kg；屈肌MS为男性0.18 - 1.20 Nm/kg，女性0.13 - 0.79 Nm/kg。另一方面，伸展和屈曲ROM的RIs由于其RVs的离散性质而非参数确定。伸展ROM确定的RIs为-15°至0°，屈曲ROM为105°至150°（K-L I/II级）和95°至140°（K-L III/IV级）。
专门为轻度至中度KOA患者确定的RIs范围介于年龄匹配的健康对照者和术前KOA患者之间，我们之前曾报道这两组数据用于接受全膝关节置换术的KOA患者的物理治疗管理。新得出的RIs将为针对轻度至中度KOA门诊患者的物理治疗提供客观基准。
