Van Berkel and Crandal define conceptual replication as follows:
Conceptual replication means that researchers re-test the same theoretical idea or hypothesis repeatedly, but use different populations, different ways of manipulating variables, different ways of measuring variables, or using different study designs.
Surgical treatment of joint degeneration is an excellent topic in orthopedics where conceptual replication applies very well.
de Klerk et al. conclude in their review:
Surgical debridement is an effective treatment for the disabling symptoms of primary elbow OA with an acceptable complication rate.
This is very strong statement. Authors based it on an analysis of 21 studies. The only problem is that all these studies were uncontrolled studies. It is impossible to say how these patients would have fared without an intervention. This is how I highlighted this matter some time ago in Twitter:
Several RCTs has shown that surgical debridement of degenerative knee joint is no better than sham. In this case the hypothesis which has been confirmed states that surgical debridement of degenerative joint is not beneficial. Conceptual replication means that patients with elbow osteoarthritis are randomized to arthroscopic debridement or sham procedure. I would give quite strong prior for null effect. Why would debridement of elbow joint be radically different from debridement of knee joint?
Very interesting Finnish study was published last year related to this aspect. Karelson et al. reported:
The rate of knee and shoulder arthroscopies declined after reaching a peak in 2006 and 2007, respectively. The rates of wrist, elbow and hip joint arthroscopies declined after their 2014 peak.
Several high quality RCTs have shown that arthroscopic partial meniscectomy of the knee and arthroscopic subacromial decompression in the shoulder have no clinically meaningful effect. This has lead as one might guess to decreased number of these procedures. Interestingly, at least in Finland, rates of other arthroscopic procedures have also declined. Again, why would debridement of elbow, wrist or hip joint be radically different from debridement of knee joint? This is something we should be really asking from ourselves.