Perineural Local Anesthetic Treatments for Osteoarthritic Pain

The most common disabling symptom of osteoarthritis (OA) is pain. Clinical investigations using disease-specific animal models have increased our insights into the pathophysiology of osteoarthritic pain. As the prevalence of OA continues to rise and current available treatment options give less than optimal levels of pain relief, opportunities to develop treatments to address osteoarthritic pain are increasing. Targeted administration of local anesthetics along sensory/motor nerves can provide an alternative strategy for managing osteoarthritic pain. Moreover, the development of engineered therapeutic drug delivery systems may allow for sustained perineural delivery of local anesthetics as opposed to the traditional intraarticular joint injections. This review presents an overview of (1) the pathophysiology of persistent pain associated with OA of the hip, shoulder, and knee and (2) the emerging therapeutic role of local anesthetics in providing analgesia for joint-related pain symptoms. Lay Summary Osteoarthritic pain is one of the most common reasons patients seek medical attention. However, common oral analgesic treatments are fraught with several clinical challenges including off-target side-effects, addiction, and short duration of analgesic efficacy. Direct delivery of local anesthetics to the perineural space surrounding peripheral neurons is proving to be forthcoming clinical approach that may be superior to traditional analgesic approaches. This review describes current diagnostic and therapeutic approaches for osteoarthritis pain and the clinical data regarding local anesthetic injections for shoulder, hip, and knee joint pain. Furthermore, this review describes the future directions for clinical use of ultrasound-guidance for focal drug delivery and biomaterial drug delivery systems for sustained drug release which both may provide further advancements for analgesic treatments of osteoarthritis pain.