Combined injection of hyaluronic acid and platelet-rich plasma for alleviating chronic pain and improving range of motion in post-traumatic knee osteoarthritis over a short term

Introduction: Posttraumatic knee osteoarthritis (PTKOA) is the most common type of osteoarthritis affecting younger people's quality of life. Platelet-rich plasma (PRP) administration increases the release of growth factors that aid cartilage regeneration, providing pain relief in patients with knee osteoarthritis. Hyaluronic acid (HA) administration elicits anti-inflammatory, antinociceptive, and chondroprotective effects, as well as normalizing endogenous HA synthesis. Purpose: This paper aims to elucidate the short-term effects of combined PRP-HA injection on chronic knee pain and knee range of motion (ROM) in patients with PTKOA. Methods: Patients with a traceable history of PTKOA-related trauma and subsequent chronic knee pain were recruited retrospectively. All patients had received one combined dose of PRP-HA in the first week, followed by one weekly dose of HA alone over the following 2 weeks. Knee pain (evaluated on a visual analog scale [VAS] at rest and when walking) and knee ROM before and 6 and 24 weeks after treatment were recorded. Results: In total, 33 patients (18 men and 15 women; mean age, 50.5 ± 10.4 years; body mass index, 26.4 ± 6.5 kg/m^2) were included. Compared with those before treatment, mean VAS scores (resting and walking) significantly improved 6 weeks after treatment, and this effect persisted for another 18 weeks. Moreover, patients with Kellgren-Lawrence grade 2 osteoarthritis demonstrated better improvements in VAS scores and knee ROM than did those with Kellgren-Lawrence grade 2 osteoarthritis. Conclusion: Combined PRP and HA injections provided effective improvements in chronic knee pain and ROM in patients aged 40-65 years old with PTKOA, which persisted over 24 weeks.