Platelet-rich plasma vs. steroid injections for hamstring injury—is there really a choice?

Objective To assess the effectiveness of pain relief in patients with grade 2 proximal hamstring injury, treated with platelet-rich plasma (PRP) or corticosteroid injection, by using the primary outcome of visual analog scale (VAS) at 1 week and 4 weeks of follow-up. Materials and methods A single institution retrospective study was performed for image-guided PRP or steroid injections between 12/1/2015 and 10/30/2017 for proximal hamstring injuries. VAS was measured at 1 week and 4 weeks post-injection via telephone interviews and the pain response was recorded into two groups (negative/no change vs. positive). A comparison of pain responses between PRP and steroid was conducted by generalized estimating equation. Results Among 56 patients, 32 received PRP and 24 received steroid injections with ages from 13 to 75 years old. At 1 week post-injection follow-up, 23 patients (71.9%) from the PRP group and 11 patients (45.8%) from the steroid group showed positive response. After controlling for age, pre-procedure pain level, and gender, the positive response rate in the PRP group was higher than the steroid group (aOR: 4.04, 95% CI: 1.04–15.63, p value = 0.04). At 4 weeks post-injection, 23 patients (71.9%) from the PRP group and 13 patients (54.2%) from the steroid group showed positive response with no statistical significance (aOR: 2.48, 95% CI: 0.63–9.79, p value = 0.19). Conclusions The PRP group had shown more favorable response compared to steroid group at 1 week post-injection, which suggests that PRP therapy can be considered as a conservative treatment choice for grade 2 proximal hamstring injuries with better short-term pain relief based on limited pilot data.