Summary

In a prospective randomized study comprising 84 patients (142 knees), it was found that the effect of Platelet rich plasma (PRP) is long lasting than Hyaluronic acid (HA) and the PRP seems to be better for pain relief and functionality in the short and mid-term periods, especially in the younger population with lower degree of osteoarthritis knee.

Abstract

Background

Osteoarthritis (OA) is a degenerative disease in which catabolic process supervene the reparative process; it has been established by the presence of catabolic enzymes, inflammatory cells and fragmented Hyaluronic Acid (HA). Management is mainly directed towards reduction of inflammation, lubrication of the joint or stimulating the process of repair. An intra-articular injection is an option if conservative treatment fails. In most of the cases it works but for a variable period and with inconsistent results. The superiority of one injection over the other is a controversial topic. We have done randomized, comparative cohort study to compare the short and midterm results of commonly used an intra-articular injection of HA compared with the relatively newer regenerative technique in the form of intra-articular Platelet Rich Plasma (PRP) in a moderate degree of knee OA.

Methods

A total of 84 patients (142knees) with moderate OA (Kellgren grade II and III) were selected for the study. All the patients were randomized with a computer based program. Forty-two patients (72 knees) were given 6 ml (48 mg) HA (Synvisc-one TM, Sanofi, and Genzyme). Another 42 patients (69 knees) were given 6 ml of autologous PRP. The outcome was evaluated as per Knee Society score (KSS), and visual analogue scale (VAS) and compared by using Wilcoxon sign rank test and Wilcoxon rank sum test. To see how the age and grade of OA affect the result, both the group was further divided into subgroups of age = 50 years versus >50 years and grade II versus grade III for comparison.

Result
Baseline demographic data, KSS for pain and function of both groups, was statistically comparable (P-value for KSS pain and function were 0.47 and 0.49 respectively). Large initial improvement in KSS score of HA group was seen compared to PRP group. Improvement of HA group was maintained till 12 weeks after that it started declining. In PRP group, the initial improvement was slow but it was continuously progressive till 24 weeks and at the end of study (24weeks) PRP was statistically significantly better than HA (P-value 0.03). Maximum KSS pain score achieved in HA group was 80.24 at 12 weeks while that of PRP was 81.54 at 24 weeks. Score for KSS function followed a similar trend as KSS pain score. On VAS score baseline score of HA was significantly better, the gradual decline of the score was noted in HA just after a first week and a decline in PRP group after 12 weeks. At 24 weeks PRP was significantly better than HA (P-value <0.01). Younger age subgroup and those with a relatively lower degree of OA did better in both groups.

Conclusion

Both the intraarticular injections of HA and PRP are effective in pain relief for knee OA. However, the effect of PRP is longer lasting than HA, and the PRP seems to be better for pain relief and functionality in the short and mid-term periods, especially in the younger population with a lower degree of OA.