Total knee arthroplasty (TKA) is an increasingly utilized, end-stage, cost-effective
treatment for knee osteoarthritis (OA), one of the leading causes of disability worldwide
whose hallmark symptoms include pain, stiffness, limited range of motion, and physical
mobility limitations. The mechanisms of pain in OA, like most chronic pain conditions, are
complex, multifaceted, and involve both central and peripheral sensitization , as well as
reward system dysfunction. Despite its overall efficacy, a significant portion of patients
with TKA (10-34%) continue to experience painful joints following the procedure , while an
estimated 20% are dissatisfied with the outcome of their procedure. Further, an estimated 20%
experience significant post-operative psychological distress in the months following surgery,
which longitudinally predicts poorer functional outcomes. TKA on average fails to improve
pain and function to a level comparable to the general population, or to the level achieved
by other joint replacement procedures (i.e., hip arthroplasty) . These limitations highlight
an urgent need to investigate safe and scalable strategies to improve TKA outcomes.
Psychosocial processes have a clinically meaningful role in shaping TKA outcomes.
Well-established presurgical cognitive and affective risk factors include pain
catastrophizing , kinesiophobia , poor outcome expectations and reward system dysfunction .
Meanwhile, emerging research suggests that positive, resilience-related factors such as
positive affect, vitality, vigor, social support, self-efficacy, and global, trait-like
resilience predict more favorable TKA outcomes.
Major Gap in Knowledge
Despite known, modifiable psychological risk and resilience factors known to impact TKA
outcomes, only recently have psychosocial processes in TKA been targeted in clinical trials.
There are a handful of investigations which have variously employed psychoeducation, guided
imagery, motivational interviewing, and cognitive-behavioral approaches, which have
demonstrated modest to poor efficacy in impacting postsurgical pain and function. Pain
neuroscience education (PNE) is a relatively recent psychosocial intervention approach to
chronic pain that educates patients on the modern neuroscientific understanding of mechanisms
(e.g., central and peripheral sensitization), whose efficacy appears to be optimized when
combined with an additional active treatment (e.g., physical therapy) informed by the
patent's reconceptualization of pain (away from biomedical or biomechanical understanding and
towards a modern neuroscientific understanding) achieved through PNE. Initial studies on PNE
alone in TKA patients show a favorable effect on patient satisfaction with the TKA procedure
and psychosocial risk factors including pain catastrophizing and kinesiophobia but no effect
on pain or function.
How Proposed Work Will Fill the Gaps
The present study will address major gaps in knowledge by testing a novel prophylactic
psychological intervention for TKA patients that targets reward system dysfunction, a central
driver of chronic pain states. Specifically, the study will test a novel Savoring Meditation
(SM) intervention, which teaches patients how to augment positive affective functioning via
meditating on a positive autobiographical memory. In addition, using a pain neuroscience
education framework, SM will also educate participants on the neurophysiological basis for
engaging in savoring meditation. Specifically, the intervention will educate patients about
the reward system in the brain, and how deficits in reward system functioning serve to
maintain pain. Subsequently, the intervention will explain to patients that savoring
meditation has been empirically shown and is optimally suited to reduce pain vis-a-vis
augmented reward system functioning. Patients randomized to SM will engage in 4 sessions of
SM with a trained interventionist. They will be encouraged to use their SM skills in the
postsurgical period to manage pain. The study will compare the efficacy of SM to a Pain
Self-Management and Education (PSME) condition, wherein patients will learn about biological,
psychological, and social drivers of pain. The PSME condition will control for therapeutic
alliance and treatment expectancies. It is hypothesized that patients who undergo 4 sessions
of SM will demonstrate reduced clinical pain and prescription opioid use across major
assessment timepoints (post-treatment, 6-weeks, and 3-months), relative to PSME. Reward
system function measured via self-report, affective pain modulation task performance, and
electroencephalographic (EEG) based biomarkers will be investigated as a secondary outcome.
