What Have We Learned About the Course of Clinical Outcomes After Total Knee or Hip Arthroplasty?

Objective To review homogeneous subgroups with a distinct course of clinical outcomes, to review the course of clinical outcomes in the study population as a whole, where applicable, and to determine the patient characteristics associated with the distinct courses after total knee or hip arthroplasty. Methods MEDLINE and PsycInfo databases were searched for relevant studies. Selection criteria were patients >= 18 years old, patients at high risk of or diagnosed with knee or hip osteoarthritis, studies aiming to identify homogeneous subgroups with distinct trajectories or describe the mean change of clinical outcomes, and methodology and analysis designed to identify trajectories (longitudinal design and repeated measures). Results Of the 5,128 abstracts retrieved, 23 met inclusion criteria. Most studies (12 of 23) focused on the mean course of outcomes after knee arthroplasty, and the most frequent outcomes reported were pain and physical function. Statistical approaches used, the number of trajectories, and predictors identified were heterogeneous across studies. Strong evidence was found that female sex, a high body mass index, poor mental health, a high number of painful sites, high preoperative pain level, a low preoperative lower-extremity functioning, and knee arthroplasty were predictors of bad evolution. Conclusion Few studies have used trajectory analysis to describe the course of clinical outcomes in homogeneous subgroups of patients. Yet this approach could lead to the identification of predictors of poor postsurgery outcomes that are specific to patients and thus to earlier identification of poor responders to total arthroplasty.