Chronic Post-Surgical Pain After Hip and Knee Arthroplasty: An Update on Mechanisms, Risk Factors, and Interventional Treatment Modalities.

In the United States, hip and knee arthroplasties are amongst the most frequently performed elective surgeries. While generally effective, a subset of patients develop chronic post-surgical pain (CPSP) in the affected joint. The management of CPSP is an incredibly important area of ongoing research, as the prevalence of individuals with arthroplasties continues to climb. Currently, there is a lack of best practice guidelines dedicated to CPSP of the hip and knee following arthroplasty. While conservative modalities including physical rehabilitation, pharmacologics, and psychological interventions remain the cornerstone of management of CPSP, this review aims to fill an important knowledge gap by providing an overview of the existing interventional treatment modalities. Procedures discussed include radiofrequency ablation (RFA), pulsed radiofrequency (PRF), peripheral nerve stimulation (PNS), spinal cord stimulation (SCS), dorsal root ganglion (DRG) stimulation, and intrathecal drug delivery systems (IDDS). Moreover, it explores other emerging therapies. To date, RFA for CPSP has the most supporting evidence, with strong support for cooled RFA. However, neuromodulation techniques including PRF, PNS, SCS and DRG stimulation each may offer promising results in treating CPSP of the hip and knee. Ultimately, without comparative analyses, the decision regarding which to pursue relies upon shared decision-making with the patient focused on tailoring treatments to the presumed underlying mechanism in line with resource availability and associated costs.