Stratford Paul, Kennedy Deborah, Clarke Hance
School of Rehabilitation Science, McMaster University, Hamilton, ON, Canada.
Holland Orthopaedic & Arthritic Centre of Sunnybrook Health Sciences Centre, Toronto, ON, Canada.
Arthroplast Today. 2018 Oct 15;4(4):488-492. doi: 10.1016/j.artd.2018.09.003. eCollection 2018 Dec.
Investigations have revealed the Western Ontario and McMaster Universities Osteoarthritis Index's (WOMAC) inability to provide distinct assessments of pain and function. The Lower Extremity Functional Scale (LEFS) has not displayed this deficiency. Our purposes were to investigate further the WOMAC physical function's (WOMAC-PF) ability to accurately assess lower extremity mobility in patients undergoing total knee arthroplasty (TKA) and to establish a relationship between pre- and post-TKA WOMAC-PF and LEFS scores that accounts for the apparent bias WOMAC pain scores impose on WOMAC-PF scores.
WOMAC, LEFS, and Timed-up-and-go measures were administered before TKA and 4 days, 6 weeks, and 3 months after TKA. To evaluate the WOMAC-PF and LEFS ability to provide a distinct assessment of pain and function, a paired t-test compared pre-TKA and 4 days after TKA values. Generalized estimating equation (GEE) analysis assessed the relationship between pre- and post-TKA values: dependent variable WOMAC-PF scores; independent variables LEFS scores, and measurement occasions.
Timed-up-and-go and LEFS demonstrated a reduction in lower extremity function ( < .001); pain decreased ( < .001); and there was no significant change in WOMAC-PF scores ( = .61). GEE analysis revealed a linear relationship between WOMAC-PF and LEFS with similar slope coefficients for all four occasions. The relationship between WOMAC-PF and LEFS scores was virtually identical for the postarthroplasty assessment occasions.
Our findings support previous investigations that showed the WOMAC-PF's inability to provide a valid assessment in change in function. The GEE analysis coefficients can be used to convert LEFS scores to WOMAC-PF scores that adjust for the bias between pre- and post-TKA assessments.
研究表明，西安大略和麦克马斯特大学骨关节炎指数（WOMAC）无法对疼痛和功能进行明确评估。下肢功能量表（LEFS）则未表现出这一缺陷。我们的目的是进一步研究WOMAC身体功能部分（WOMAC-PF）准确评估全膝关节置换术（TKA）患者下肢活动度的能力，并建立TKA术前和术后WOMAC-PF与LEFS评分之间的关系，以解释WOMAC疼痛评分对WOMAC-PF评分造成的明显偏差。
在TKA术前以及术后4天、6周和3个月时，分别进行WOMAC、LEFS和计时起立行走测试。为评估WOMAC-PF和LEFS对疼痛和功能进行明确评估的能力，采用配对t检验比较TKA术前和术后4天的值。广义估计方程（GEE）分析评估TKA术前和术后值之间的关系：因变量为WOMAC-PF评分；自变量为LEFS评分和测量时间点。
计时起立行走测试和LEFS显示下肢功能下降（P<0.001）；疼痛减轻（P<0.001）；而WOMAC-PF评分无显著变化（P=0.61）。GEE分析显示，WOMAC-PF与LEFS之间呈线性关系，在所有四个时间点的斜率系数相似。在关节置换术后评估时间点，WOMAC-PF与LEFS评分之间的关系几乎相同。
我们的研究结果支持先前的研究，即WOMAC-PF无法有效评估功能变化。GEE分析系数可用于将LEFS评分转换为WOMAC-PF评分，以调整TKA术前和术后评估之间的偏差。
