Most knee PRP studies report only short term results and fail to assess total knee replacement (TKR) avoidance/joint survivorship as an outcome. We wished to evaluate the efficacy of PRP at 3 year follow up with particular attention to TKR avoidance.
This prospective study examines the outcomes of patients with medial and lateral KOA who were treated with PRP and followed for 3 to 7 years. 568 knees (487 patients) with KOA were treated with PRP injections. All patients had medial or lateral KOA diagnosed by physical exam and confirmed by x-ray. Outcomes included joint survivorship, global improvement, safety, Single Assessment Numeric Evaluation (SANE) scores and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Evaluations were performed 6 months, 1 year, 18 months, 2 years, and 3 years after treatment.
207 males and 280 females with a mean age of 65 years were treated. 456 patients had medial KOA and 112 had lateral KOA. No serious adverse events were seen. Patients were separated into 6 groups based on joint space measured on standing AP x-ray (0-1mm, 2-4mm and 5+mm) and site of KOA (medial or lateral). 101 knees received total knee arthroplasty (TKA) by 36 months, for a total survivorship of 75% at 3 years. Survivorship was 64% for the 0-1mm group, 77% for the 2-4mm group and 91% for the 5+mm group at 3 years. There were significant improvements in both SANE scores and WOMAC scores by 6 month follow up and these improvements were maintained throughout the three year follow up. Linear regression analysis demonstrated no significant change in efficacy when factoring in BMI and age.
PRP for the treatment of medial and/or lateral KOA has excellent survivorship out to 3 years even in bone on bone, elderly, and obese patients.