P118 - Up to 12 months improvement of knee OA after PRP injections; however is this of clinical relevance?
Abstract
Purpose
Osteoarthritis (OA) treatment should aim at symptom reduction and thereby delaying or even preventing arthroplasty. Injections of platelet-rich plasma (PRP) in patients with Kellgren and Lawrence(K&L) grade II and III OA have shown good clinical outcome in several trials1–4, but limited effect in another trial5. It is not known whether different subgroups of patients respond better to treatment with PRP. The aim of this study is to assess clinical improvement after PRP injections and to determine whether K&L grade, age, gender and BMI predict clinical outcomes.
Methods and Materials
A prospective cohort of 137 OA patients received three consecutive injections with PRP, with one week interval between the injections. Knee Osteoarthritis Outcome Scores (KOOS) was evaluated at baseline and 3, 6 and 12 months after the last injection. Improvement compared to baseline was assessed for all subdomains and total KOOS. Univariate linear regression was performed to assess predictive value of age, sex, BMI, K&L grade and history of knee trauma. Generalized estimating equation (GEE) was used to explore association between all factors and clinical outcome.
Results
Baseline characteristics are shown in table 1. Compared to baseline, total KOOS improved with 5.81±13.39 at 3 months, 5.96±14.26 at 6 months and 6.78±16.26 at 12 months (all p<0.01). The improvement was similar in all 5 subdomains of the KOOS. Female gender was a predictor of better outcomes at 3 months (p<0.05), but this effect lost significance at 6 months. At 6 months K&L grade 4 (p=0.05) predicted better outcomes. GEE indicated older age increases clinical improvement (<0.05).
Conclusion
PRP treatment improved KOOS-score at 3, 6, and 12 months, although this difference did not reach the minimally clinical relevant difference described for KOOS. Older age and female sex predict better outcome after PRP treatment.
