Hysing-Dahl Trine, Faleide Anne Gro Heyn, Waaler Per Arne Skarstein, Inderhaug Eivind
Department of Surgery Haraldsplass Deaconess Hospital Bergen Norway.
Department of Clinical Medicine University of Bergen Bergen Norway.
J Exp Orthop. 2025 Apr 1;12(2):e70146. doi: 10.1002/jeo2.70146. eCollection 2025 Apr.
The purpose of the current study was to evaluate important aspects of interpretability (floor and ceiling effects) for the Knee injury and Osteoarthritis Outcome Score (KOOS) in patients with patellar instability. Secondarily, the study aims to provide minimal important clinical difference (MICD) values for all subscales in this patient category.
Patients undergoing patella stabilising surgery with an individualised approach based on anatomic deviation were prospectively included if (1) ≥13 years of age at the time of surgery, (2) fluent in Norwegian and (3) able to understand and complete the questionnaires. Patients were excluded if they had concomitant bony and/or knee ligament injuries. KOOS was completed before and 6 months after surgery. of the KOOS was evaluated according to recommendations from COnsensus-based Standards for the selection of health Measurement INstruments. A is considered to be present if the number of patients that had a score in the lower (0-10) or upper (90-100) end of the scale exceeded 15%. This was identified with a distribution-based approach with standard deviation (SD) of the change score between pre- and postoperative scores using the following equation: MICD = 0.5 × SD.
A substantial ceiling effect was present in the KOOS subscales and activities of daily living () measured prior to surgery, and in all, except the quality of life subscale, 6 months after surgery. KOOS demonstrated the highest number of patients, 46% preoperatively and 72% postoperatively with a ceiling effect. In addition, 32% of patients had the best possible score on the subscale 6 months after surgery. The only subscale that displayed a floor effect was the preoperative KOOS . The MICD for the different subscales ranged from 7.6 to 12.4.
The substantial ceiling effect in the current implies that the KOOS is not suited to evaluate the long-term effect of treatment in patients with patellar instability.
Level II.
本研究旨在评估髌股关节不稳定患者的膝关节损伤和骨关节炎疗效评分（KOOS）在可解释性方面的重要内容（地板效应和天花板效应）。其次，本研究旨在提供该患者群体所有子量表的最小重要临床差异（MICD）值。
采用基于解剖学偏差的个体化方法进行髌骨稳定手术的患者，若符合以下条件则前瞻性纳入研究：（1）手术时年龄≥13岁；（2）挪威语流利；（3）能够理解并完成问卷。若患者伴有骨和/或膝关节韧带损伤，则将其排除。在手术前和术后6个月完成KOOS评估。根据基于共识的健康测量工具选择标准的建议评估KOOS的天花板效应。如果量表低端（0 - 10）或高端（90 - 100）得分的患者数量超过15%，则认为存在天花板效应。这是通过基于分布的方法确定的，使用术前和术后得分之间变化分数的标准差（SD），计算公式如下：MICD = 0.5×SD。
术前测量的KOOS子量表疼痛和日常生活活动（ADL）以及术后6个月除生活质量子量表外的所有子量表均存在显著的天花板效应。KOOS疼痛显示天花板效应的患者数量最多，术前为46%，术后为72%。此外，32%的患者在术后6个月的ADL子量表上获得了可能的最高分。唯一显示地板效应的子量表是术前的KOOS运动功能。不同子量表的MICD范围为7.6至12.4。
当前研究中显著的天花板效应表明，KOOS不适用于评估髌股关节不稳定患者治疗的长期效果。
二级。
