A structured PRP pathway beat ad hoc PRP, but did not test PRP itself

Design

Multicentre, double-blind randomised trial

Population

240 patients with Kellgren-Lawrence I–II knee osteoarthritis, China

Primary outcome

VAS, WOMAC and IKDC at 12 months

Effect

VAS −2.98 (−3.64 to −2.32); WOMAC −8.63; adverse events 14.8% vs 31.9%

A double-blind randomised trial at three Chinese hospitals enrolled 240 patients with Kellgren-Lawrence grade I–II knee osteoarthritis. Half received a standardised PRP pathway: defined selection criteria, quality-controlled leukocyte-poor PRP, ultrasound-guided injection, staged rehabilitation and scheduled follow-up. The other half received PRP as their physician usually gave it.

At 12 months the pathway group had greater falls in pain (VAS mean difference −2.98) and WOMAC score (−8.63), and greater IKDC gains (+10.25), all P < .001. More reached clinically important improvement, satisfaction was higher, and adverse events were less than half as frequent (14.8% vs 31.9%). Costs were similar.

This tells us how PRP is delivered matters — guidance, product quality and rehabilitation all plausibly contribute. It does not tell us whether PRP beats saline or exercise alone, because there was no placebo arm, and placebo-controlled trials have been mixed. In India, where PRP is widely offered with variable preparation, the honest reading is: if you offer it, standardise it; but do not cite this trial as proof that PRP works.

• If you offer PRP for early knee osteoarthritis, use a written protocol for selection, preparation and injection
• Use image guidance and a leukocyte-poor preparation where available
• Pair any injection with a structured exercise and rehabilitation programme
• Tell patients that evidence for PRP over placebo remains mixed
• Record adverse events; ad hoc delivery had twice the rate in this trial

Why it matters

Much of the variation in PRP results may come from how it is delivered, not only whether it is used.

Don't overread it

With no placebo arm and bundled components, the trial does not establish that PRP itself is effective.

The statistics, in plain English

A 3-point fall on a 10-point pain scale is a large difference, but it compares two ways of delivering PRP, not PRP with nothing. Because the pathway bundled several components, including rehabilitation, it cannot say which part produced the benefit.

Read the rest in the app

You have read your two free briefings this month. The app carries all 27 specialties, every morning, free — and this finding is waiting in it.

Get Daily Doctor — free

Scan to keep reading on your phone. No account needed to start.