September 28, 2016
Assignment 1 - Rehabilitation Psychology
The results of an experiment that compared the effectiveness arthroscopic
surgery to placebo surgeries was published by the New England Journal of Medicine in
July 2002. The experiment was performed because researchers wanted to assess the
efficacy of arthroscopy for treating osteoarthritis in the knee. Patients who have
undergone arthroscopy have given account of symptomatic relief for their knee pain.
Essentially the rationale for the execution of the study was to acquire evidence in order
to determine if arthroscopic lavage (with or without the removal of damaged tissue)
yielded better results than a placebo procedure.
The study was designed and set up in such a way that both the assessors/
researchers, as well and the test subjects were blinded - it was a double-blind
experiment. The blinding of both the assessors and the test subjects was advantageous
because it eliminated any bias for both counterparts. Due to the double blinding of the
test subjects/participants and researchers, the impartiality of everybody involved in the
experiment was assured. Participants who were 75 years old or younger were selected.
Furthermore, the participants who met the age requirement had to have osteoarthritis of
the knee, and due to their condition, had to have experienced moderate knee pain of
greater than or equal to four, on a scale of zero to ten. In order to be eligible to
participate in the experiment, participants were required to have undergone maximal
treatment in the last six months, and not receive arthroscopy of the knee in the previous
two years. In total, 180 patients participated in the study. Participants were randomly
allocated to receive arthroscopic lavage, arthroscopic débridement, or a placebo
operation. The randomization process was initiated by dividing the participants into
three groups according to the intensity of the pain they experienced due to their
osteoarthritis. Sealed, stratified, and sequentially numbered envelops cottoned the
treatment assignments for each participants. Treatment assignments were revealed to
the surgeon, but the patients were never informed which treatment they underwent. The
experiences and outcomes of the surgeries were monitored over a 24-month period, in
which participants completed self-reported scores of pain and function. Three of the
scores measured pain, and two of the scores measured pain. Participants were also
subject to an objective test where they were engaged walking and stair climbing.
The intervention used with the experimental group in this study was the use of
arthroscopic lavage or debridement, because the efficacy of arthroscopic surgery was
being tested in differentiation to the comparison group, in which participants received a
sham surgery. In the experimental (interventional) group, participants who underwent
the lavage procedure had their joints rinsed with a minimum of 10 litres of fluid,...