This trial asks a previously unaddressed and important clinical question about management
of knee osteoarthritis (OA) patients.
Current recommendations of management of knee OA highlight weight loss as first choice
and weight loss is a potential principal intervention against knee OA as a co-morbidity
to obesity.
Knee arthroplasty (KA) is an effective treatment of knee OA in patients with pain that
limits the patient's ability to perform their normal daily activities. KA is considered a
successful orthopedic procedure to alleviate knee pain and disability in end stage knee
OA. The demand for KA is large and growing worldwide; in Denmark alone approximately
10,000 KA procedures are performed annually, which pose a substantial economic burden to
the health care system. KA carries relatively low risk both in terms of systemic
complications and suboptimal outcomes for the joint itself. KA is one of the most
effective surgical procedures available with very few contraindications. As a result, the
demand from patients for these treatments continues to rise along with the confidence of
surgeons to offer KA to a wider range of patients in terms of age, disability and
co-morbidities.
However, the quality of evidence for KA efficacy is low as very few randomized controlled
trials (RCTs) exist - particularly with respect to comparative effectiveness. To inform
decision making for obese individuals with knee OA, it is important to evaluate the
comparative effectiveness of a weight loss intervention against KA. The present trial has
been designed to compare the effectiveness of weight loss and KA in individuals with
obesity and knee OA.
This study addresses this question by comparing two recommended and potentially competing
strategies in the management of obese knee OA patients:
Strategy A. A 3-months waiting list followed by a 12-week Intensive supervised diet
intervention; Strategy B. A 3-months waiting list followed by surgical knee arthroplasty
including standard post-operative rehabilitation.
Although a trial to address this question is needed, so far this study has not been
carried out, presumably because trials in routine clinical practice are quite expensive
and health care professionals (HCPs) responsible for delivery of either strategy have
little incentive to compare KA to less expensive, non-surgical therapies. Moreover, the
Danish Health and Medicines Authority have not required such comparisons. Since the
Danish healthcare system already provides KA at public hospitals, it appears that such
settings are ideally suited to address this question and, in the process, help clinicians
around the world make better judgments for their patients with OA.
The sparse comparative effectiveness evidence that could inform clinical decision making,
combined with existing evidence from RCTs and observational studies on knee surgery and
weight loss provide a clear-cut ethical and scientific justification for the trial
described in this protocol.