The effects of injecting intra-articular platelet-rich plasma or prolotherapy on pain score and function in knee osteoarthritis.

Introduction: Osteoarthritis (OA) is a chronic joint disease that usually occurs in older people and leads to pain and disabilities. OA treatment ranges from drug therapy to surgery. Drug and rehabilitation therapy are preferred over surgery, and, especially, there is a tendency toward compounds causing regenerative changes in the knee joint. In the present study, the effects of platelet-rich plasma (PRP) injection and prolotherapy (PRL) were examined on the level of pain and function of the knee joint in patients with OA.

Methodology: After fulfilling the inclusion criteria and signing the informed consent form, 42 patients with knee OA were scheduled for intra-articular injection in the present randomized, double-blind, clinical trial. Following admission to the operating pain room, the condition of the patient's knee was evaluated first via the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and, then, ultrasound-guided knee injection was done. Accordingly, patients in the PRP therapy group received 7 mL PRP solution and those in the PRL group received 7 mL 25% dextrose. Using the WOMAC, levels of pain and knee function were evaluated and recorded for each patient immediately prior to the first injection as well as at 1 month (immediately prior to the second injection), 2 months (a month after the second injection), and 6 months later. Data collected were analyzed using the SPSS v.20.

Results: During the first and second months, a rapid decrease in the overall WOMAC score was observed in both groups. The overall WOMAC score increased at the sixth month, but was lower than the overall WOMAC score in the first month. Statistical analysis indicated that the overall WOMAC score significantly decreased in both groups of patients over 6 months.

Conclusion: Results of the present study suggested a significant decrease in the overall WOMAC score of patients who undergo either PRP therapy or PRL. This positive change in the overall WOMAC score led to an improvement in the quality of life of patients with knee OA shortly after the first injection. PRP injection is more effective than PRL in the treatment of knee OA.