Role of Triple Injection Platelet-Rich Plasma for Osteoarthritis Knees: A 2 Years Follow-Up Study

Abstract

Purpose: To assess the clinical outcomes of intra-articular Platelet-rich plasma (PRP) injection in knee osteoarthritis (OA) at 2 year follow-up.

Methods: This was a prospective interventional study. 68 cases (105 knees) with Kellgren-Lawrence (KL) grades I, II and III knee OA received 3 intra-articular injections of PRP 1 month apart. The cases were followed up for 2-years. Outcomes were measured using Western Ontario and McMaster Universities Arthritis Index (WOMAC) score and Visual analog scale (VAS) scores.

Results: The mean age was 51.7 years. 18 knees had KL grade I, 55 had grade II and 32 had grade III OA. The mean pre-treatment VAS score decreased significantly at 1 year (mean difference - 5.3, p = 0.003) and 2 year follow-up (mean difference - 6, p = 0.007). The mean pre-treatment WOMAC score decreased significantly at 1 year (mean difference - 45.9, p = 0.011) and at 2 year (mean difference - 52.4, p = 0.009). The WOMAC and VAS scores improved significantly from baseline to final follow-up across all KL grades (p = 0.001 and 0.001, 0.009 and 0.007, 0.021 and 0.017 for WOMAC and VAS across KL grade I, II and III, respectively). There was no significant differences in WOMAC and VAS scores between three KL grades at final follow-up (p = 0.17 and 0.09, respectively), although the baseline scores had significant difference (p = 0.001 for both VAS and WOMAC) with worse scores in higher KL grades. The variables like age, sex, BMI, KL grade, baseline VAS and baseline WOMAC did not predict the final VAS and WOMAC scores.

Conclusion: Triple injection of intra-articular PRP given one month apart significantly relieves the symptoms of knee OA till 2 years in KL grade I, II and III. The improvement in symptoms at 2-year follow-up did not differ across different KL grades.

Keywords: Intra-articular injection; Knee; Osteoarthritis; Outcomes; Platelet-rich plasma.