Pain and Function After Orthopedic Surgery

Primary indications for major joint surgery include limited joint function and pain. Although joint replacement or repair surgery is usually remarkably effective, in some cases pain and function are worse or not improved after surgery. Chronic pain after some surgical procedures, e.g., phantom limb pain after extremity amputation, has been long recognized, but more recent investigations suggest that chronic pain after physical injury including that of major surgery is not uncommon. The purpose of this study is to provide preliminary data for a Program Project Grant to the National Institutes of Health to examine specific hypotheses regarding identifying patients at risk for chronic pain after surgery and probing mechanisms which may be manipulated to decrease this risk.

Methods:

Patients who are undergoing elective orthopedic surgery: unicompartmental knee replacement or a total knee replacement will be approached and asked to provide consent to participate in 6 months of observation after their surgery. During this time, participants will not alter their usual treatment in any way (i.e., no treatment algorithms will be altered for this study), but will complete diaries and survey instruments at numerous intervals.

Objectives:

1. To demonstrate the feasibility of conducting this protocol in this clinical population. The execution of this study will allow us to identify expected enrollment rates, patient drop-out rates, and other threats to the accurate assessment of the course of pain after major joint surgery.
2. To estimate the individual variability in pain trajectories over time and to obtain effect size estimates for factors that predict pain trajectory.