Pandit Hemant, Lineham Beth, Muli Annah, Kelly Rachel, Collier Howard, Mujica-Mota Ruben, Metcalfe Andrew, Simpson Hamish, Murray David, Sharma Hemant, McGonagle Dennis, Ellard David R, Croft Julie, Stokes Jamie, Harwood Paul, Hamilton Thomas, Stocken Deborah
Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, Leeds Institute of Medical Research, Leeds, UK.
Chapel Allerton Hospital, Leeds, UK.
Health Technol Assess. 2025 Nov;29(60):1-29. doi: 10.3310/ANDK1124.
Patients with symptoms of pain and restricted function related to knee osteoarthritis are typically offered a knee replacement. However, a proportion remain dissatisfied with their outcomes, and the failure risk is disproportionately higher in the young. Knee joint distraction may be an intervention to postpone the time to knee replacement in this patient population.
The primary objective of the Knee Arthroplasty versus Joint Distraction Study for Osteoarthritis (KARDS) was to evaluate the effectiveness of knee joint distraction compared to knee replacement based on patient-reported pain 12 months post surgery using the Knee Injury and Osteoarthritis Outcomes Score pain score as the primary outcome.
KARDS was an open-label, two-arm individually randomised controlled non-inferiority trial with an embedded 12-month internal pilot phase and process evaluation to evaluate recruitment feasibility. A hybrid expertise design was used to account for surgeon expertise and potential lack of individual equipoise. The trial was closed to recruitment early following cessation of elective orthopaedic surgery secondary to COVID-19 pandemic. Descriptive statistics are reported.
United Kingdom National Health Service Trusts.
Adult patients aged < 65 years with symptoms severe enough to warrant knee replacement, in the opinion of the treating clinician.
Participants were randomised to receive either knee joint distraction (static distraction of 5 mm, using external fixator for 6 weeks) or knee replacement.
Twenty-four participants were randomised from a single centre between March 2021 and October 2022 with minimum 3-month safety follow-up post surgery. Eleven participants were randomised to knee joint distraction and 13 to knee replacement. Seventeen patients were male (71%), median age 60 (47-65) years. One patient withdrew due to being medically unfit for surgery and two received a different treatment than which they were randomised (one crossover from each arm). The median Knee Injury and Osteoarthritis Outcomes Score pain score in the knee joint distraction group improved from 38.9 (22-50) at baseline to 55.6 (0-100) at 12 months, corresponding scores in the knee replacement improved from 30.6 (6-36) to 75.0 (50-100). Adverse events were more common with knee joint distraction, pin site infection being the commonest complications ( = 4, 58%). As part of process evaluation, we conducted semistructured qualitative interviews with staff in secondary care and with study participants. Data were analysed using thematic content analysis. One overarching theme emerged: 'An unexpected journey', which encapsulates staff and participants' experiences.
Reduced research capacity and the suspension of elective surgery following the COVID-19 pandemic caused significant recruitment barriers. Despite early termination, KARDS demonstrated that patients were willing to be recruited to a trial investigating a novel treatment for knee osteoarthritis and the trial was feasible and implementable. The limited results indicated that the technique is safe with no safety concerns. Clinical and cost-effectiveness of knee joint distraction remains uncertain. The embedded KARDS process evaluation has provided helpful insights.
Reduced research capacity at sites and suspension of elective surgery services within the United Kingdom following COVID-19 caused significant recruitment barriers to KARDS. All the recruited patients in both arms of the study were White.
As a commissioned piece of research with delivery significantly impacted by the National Health Service environment post-COVID and the impact on National Health Service surgical services, the research question remains highly relevant. Any future research in this field can be helped by the pilot data published here along with the lessons learnt.
This synopsis presents independent research funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme as award number 17/122/06.
出现与膝关节骨关节炎相关的疼痛和功能受限症状的患者通常会接受膝关节置换手术。然而，仍有一部分患者对手术效果不满意，而且年轻人的手术失败风险相对更高。膝关节牵张术可能是一种可推迟这类患者进行膝关节置换手术时间的干预措施。
骨关节炎膝关节置换与关节牵张术研究（KARDS）的主要目的是，以膝关节损伤和骨关节炎疗效评分疼痛评分为主要结局指标，评估与膝关节置换相比，膝关节牵张术在术后12个月基于患者报告的疼痛方面的有效性。
KARDS是一项开放标签、双臂个体随机对照非劣效性试验，设有一个为期12个月的内部预试验阶段和过程评估，以评估招募的可行性。采用了混合专业知识设计，以考虑外科医生的专业知识以及可能缺乏的个体平衡。该试验在因2019冠状病毒病大流行而停止择期骨科手术后提前停止招募。报告了描述性统计数据。
英国国家医疗服务体系信托基金。
年龄小于65岁、症状严重到经主治医生判断有必要进行膝关节置换的成年患者。
参与者被随机分配接受膝关节牵张术（使用外固定器进行5毫米的静态牵张，持续6周）或膝关节置换术。
2021年3月至2022年10月期间，24名参与者从单一中心被随机分组，术后至少有3个月的安全性随访。11名参与者被随机分配接受膝关节牵张术，13名接受膝关节置换术。17名患者为男性（71%），中位年龄60岁（47 - 65岁）。1名患者因身体不适合手术而退出，2名接受了与随机分配不同的治疗（每组各有1名交叉治疗）。膝关节牵张术组的膝关节损伤和骨关节炎疗效评分疼痛中位数从基线时的38.9（22 - 50）提高到12个月时的55.6（0 - 100），膝关节置换术组的相应评分从30.6（6 - 36）提高到75.0（50 - 100）。膝关节牵张术的不良事件更常见，针道感染是最常见的并发症（n = 4，58%）。作为过程评估的一部分，我们对二级医疗保健机构的工作人员和研究参与者进行了半结构化定性访谈。采用主题内容分析法对数据进行了分析。出现了一个总体主题：“一段意想不到的旅程”，它概括了工作人员和参与者的经历。
2019冠状病毒病大流行后研究能力下降以及择期手术暂停导致了重大的招募障碍。尽管提前终止，但KARDS表明患者愿意参与一项研究新型膝关节骨关节炎治疗方法的试验，并且该试验是可行且可实施的。有限的结果表明该技术是安全的，不存在安全问题。膝关节牵张术的临床和成本效益仍不确定。KARDS嵌入式过程评估提供了有益的见解。
各研究点研究能力下降以及英国境内择期手术服务暂停给KARDS造成了重大招募障碍。研究的两个组中所有招募的患者均为白人。
作为一项受委托开展的研究，其实施受到新冠疫情后国家医疗服务体系环境以及对国家医疗服务体系外科手术服务影响的显著影响，该研究问题仍然高度相关。此处发表的预试验数据以及所吸取的经验教训可为该领域未来的任何研究提供帮助。
本摘要介绍了由英国国家健康与照护研究中心（NIHR）健康技术评估项目资助的独立研究，资助编号为17/122/06。
