Enhancing Functional Outcomes in Total Knee Arthroplasty: the Role of Preoperative Genicular Radiofrequency

The International Association for the Study of Pain (IASP) has recently updated the definition of pain as "An unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage." This definition is complemented by explanatory notes emphasizing the subjective nature of pain and its modulation by biological, psychological, and social factors. Pain may therefore have detrimental effects on physical function as well as on social and psychological well-being.

Chronic postsurgical pain (CPSP) is defined as pain that develops after a surgical procedure and persists for at least three months following surgery. Historically, the risk of developing CPSP has been underestimated. Available data indicate that the incidence of postsurgical pain ranges from 5% to 85%, depending on the type of surgical procedure. Severe CPSP occurs in approximately 2% to 15% of patients, with reported rates of 17-21% after abdominal surgery, 6-55% after caesarean section, 5-65% after thoracotomy, 27% after hip arthroplasty, and 13-20% after knee arthroplasty. Specifically, after total knee arthroplasty (TKA), pain severity tends to plateau between three and six months postoperatively.

Knee osteoarthritis (OA) is a degenerative joint disease characterized by progressive cartilage wear, leading to pain, stiffness, and joint swelling. It is highly prevalent in aging populations and is strongly associated with obesity and previous joint injury. OA affects millions of individuals worldwide, with incidence and prevalence increasing markedly with age and resulting in significant functional disability. Approximately 23% of individuals over 40 years of age are affected, with prevalence rising to nearly 80% in older populations. Major risk factors include aging, elevated body mass index (BMI), joint injury, repetitive joint overload, and genetic predisposition. Since the mid-20th century, both prevalence and incidence have doubled, largely due to increased life expectancy and rising obesity rates.

The primary therapeutic goals in the management of knee osteoarthritis are pain reduction and improvement of joint mobility. Treatment follows a stepwise approach, including exercise therapy, weight reduction, physiotherapy, analgesics, nonsteroidal anti-inflammatory drugs, intra-articular corticosteroid or hyaluronic acid injections, arthroscopic procedures, and, in advanced disease, total joint replacement followed by structured rehabilitation.

Total knee arthroplasty is considered one of the most effective surgical interventions for relieving pain and restoring function in patients with severe knee osteoarthritis. Nevertheless, residual pain and limited functional improvement remain the most frequent causes of patient dissatisfaction following TKA. Both patients and surgeons may consider the procedure unsuccessful when long-term pain relief and functional recovery are inadequate. Furthermore, older adults experiencing chronic pain after TKA may suffer from impaired social relationships and social isolation. Chronic pain in this population is also associated with depression, anxiety, sleep disturbances, and long-term opioid use, all of which negatively affect health-related quality of life.