Effectiveness of a Psychological Intervention in Patients Undergoing Total Knee Arthroplasty

Effectiveness of a Psychological Intervention for the Control and Prevention of Pain and for Surgical Recovery in Patients Undergoing Total Knee Arthroplasty: a Prospective Randomized Controlled Trial

The purpose of this study is to evaluate the effectiveness of a combined Pain Neuroscience Education (PNE) and Hypnosis (HyP) psychological intervention aiming at the control and prevention of pain and promotion of post-surgical recovery in patients undergoing Total Knee Arthroplasty

This is a prospective Randomized Controlled Trial (RCT), comparing an experimental group (EG), submitted to a PNE/HyP based psychological intervention, and a control group (CG), submitted to usual treatment and care.

After recruitment and evaluation of inclusion/exclusion criteria, patients entering the study will sign the Informed Consent. Baseline evaluation is performed at 1 month pre-surgery and, afterwards, patients are randomly assigned to EG (PNE+Hyp plus usual care) or CG (usual care only). The EG will be submitted to 3 pre-surgical and 1 (or 2) post-surgical reinforcement sessions. At 1 month post-surgery, the intervention group will be subdivided and participants will be randomly assigned to receive a reinforcement session or no intervention at this point. The psychological intervention sessions are based on the educative principles of Pain Neuroscience Education and on Hypnosis strategies for the promotion of pain control, positive coping strategies and psychological variables.

Patients will be evaluated on 6 moments: T0 - baseline, 1 month pre surgery; T1 - post intervention/24h before surgery; T2 - 72h post-surgery; T3 - 1 month post surgery; T4 - 6 months post surgery; T5 - 12 months post intervention. Patients will fill in self report measures and perform physiological evaluation to analyse relevant bio-markers (salivary cortisol and α-amylase) that are related to stress levels and SNS functioning and translate the impact of psychological interventions on physiological parameters.

Inclusion Criteria:

• Planned unilateral total knee arthroplasty due to gonarthrosis
• Giving consent to participate

Exclusion Criteria:

• Inability to write and read
• Cognitive deficit (assessed by MMSE)
• Revision TKA
• Bilateral TKA
• TKA for reasons other than gonarthrosis (fracture, malignancy or infection)
• Psychiatric or neurological deficit (e.g. Schizophrenia or Alzheimers')
• Diagnosis of rheumatoid arthritis, Psoriatic arthritis, Systemic lupus erythematosus, Anquilosant spondylitis or other severe disease
• Contralateral hip or knee arthroplasty in the previous 6 months
• Planned contralateral hip or knee arthroplasty in the next 6 months