Subchondral Knee Injections: A Comprehensive Systematic Review of Current Clinical Outcomes, Safety, and Arthroplasty Delay.
Yazan Abu Salem, Carlotta Franceschi, Pietro Conte et al.
✦ AI-curated · Sources linked
In 30 seconds
This systematic review assessed clinical outcomes, safety, retreatment, and conversion to total knee arthroplasty (TKA) after intraosseous calcium phosphate (CaP), platelet-rich plasma (PRP), or mesenchymal stem cell (MSC) injections for knee osteoarthritis. It included 24 studies involving 1,109 patients, with a mean follow-up of 38 months; five studies were randomized controlled trials. Most studies reported improved pain and function. CaP outcomes varied, with TKA conversion rates ranging from 1.3% to 45%, while PRP and MSC studies reported favorable safety profiles and lower conversion rates. The review judged overall study quality modest.
Key findings
- Across 24 studies involving 1,109 patients, most reported significant improvements in pain and function.
- TKA conversion rates after CaP injection ranged from 1.3% to 45%.
- Long-term MSC studies reported sustained relief and delayed TKA over up to 15 years.
- Only one randomized controlled trial was rated as having low risk of bias.
Why it matters
Intraosseous injections target subchondral bone and may offer a joint-preserving option for selected patients with knee osteoarthritis. The review suggests potential symptom improvement and delayed arthroplasty, but the variable CaP results and modest evidence quality make comparisons and patient selection uncertain. Better standardized studies are needed to clarify which patients may benefit and how durable outcomes are.
What to keep in mind
Overall study quality was modest, and only one randomized controlled trial was rated as low risk of bias.