Sham surgery: justified but practical? A systematic review of sham surgery trials in orthopaedics

Abstract

Background: An increasing trend for sham surgery trials in minor orthopaedic procedures has beenobserved. Trial outcomes have changed the practice landscape of these procedures. However, there has been no sham surgery trial in a major orthopaedic procedure. The aims of this systematic review were to consider the ethics of sham surgery trials; to describe orthopaedic sham surgery trials conducted to date; and to consider the challenges that will need to be overcome in order to conduct sham surgery trials for major orthopaedic procedures in the future.

Methods: A systematic review of the literature and clinical trial registries was undertaken. Trials with a published main findings paper underwent a risk of bias assessment using the Cochrane Collaboration risk of bias tool, in addition to an ethical assessment based on the work of Horng and Miller. 

Results: We identified 22 sham surgery trials for minor orthopaedic procedures that have been completed, terminated, or are currently in process. Among the ten trials with a published main findings paper, only one was free from risk of bias; all others were at risk of bias. According to the ethical assessment, the benefits of a sham control were outweighed by the risks in all but two of the ten trials. Across the 22 trials with published and unpublished main findings, participant recruitment within reasonable timeframes, as well as the low threshold for crossover from the sham were recurring challenges. 

Conclusions: Researchers are obliged to carefully consider the feasibility of conducting a sham surgery trial in a major orthopaedic procedure, before drawing on limited research funds. Exploring the conditions under which patients and surgeons would find participation in a sham surgery trial acceptable, and simulating trial costs based on patient and surgeon preferences may assist funders, assessors and ethics boards to determine whether to support the conducting of future sham surgery trials in major orthopaedic procedures.

Level of evidence: Level 1