Connectivity with Iain Duncan

I am seeing a growing interest and noting more research in both PRP (platelet rich plasma) and hyaluronate/viscosupplementation therapies for the treatment of both arthritis and tendon pathologies. In many of the earlier studies  there was no control patients, but this has been improved in several recent studies. In particular I draw your attention to two recent PRP/visco-supplementation studies by Görmeli et al  for osteoarthritis of the knee, and by  Cai et al (in Medicine & Sciences in Sports & Exercise)  for rotator cuff tears (see below). Both are double blind, prospective, randomized, and controlled clinical trials.

Cai et al enrolled 184 patients with partial thickness rotator cuff tears (<1cm) and compared normal saline (NS) , Sodium hyaluronate (SH) , PRP , and combination SH with PRP. These injections were  administered via ultrasound guidance into the  subacromial bursa once a week for 4 weeks.  All the patients were followed up with clinical scores a for up to 12 months, and with a follow-up MRI at 12 months. Not surprisingly they found worsening pain and enlarging tears in the control group. There was a  significant improvement in all parameters in the treatment groups. PRP was significantly better than SH, and the combination SH+PRP was best.


This study suggest that the effects of both SH and PRP are significant and that doing them together is even more effective. I am pleased that I can offer these injection options with some confidence about improving outcomes for patients with these smaller cuff tears, which (untreated) often progress over time. 

Hyaluronic acid

It is interesting to speculate about the mechanisms of action of PRP and visco-supplementation, which seem to act independently, and possibly even synergistically. There are a number of studies that have also noted some potential synergy [1,2,3] in osteoarthritis.

Cai et al postulate that the compound provides a closed system with a cell-friendly SH network that can increase the residence time of the growth factors. This facilitate the molecular diffusion and presentation of the proteins to their receptors located in the cytoplasmic membrane of the target cells in the injured tendon.


  1. Chen WH, Lin CM, Huang CF, Hsu WC, Lee CH, Ou KL, Dubey NK, Deng WP. Functional Recovery in Osteoarthritic Chondrocytes Through Hyaluronic Acid and Platelet-Rich Plasma-Inhibited Infrapatellar Fat Pad Adipocytes. Am J Sports Med. 2016 Oct; 44(10):2696-2705.
  2. Abate M, Verna S, Schiavone C, et al. Efficacy and safety profile of a compound composed of platelet-rich plasma and hyaluronic acid in the treatment for knee osteoarthritis (preliminary results)Eur J Orthop Surg Traumatol. 2015;25:1321–6
  3. Andia I, Abate M. Knee osteoarthritis: hyaluronic acid, platelet-rich plasma or both in association? Expert Opin Biol Ther. 2014;14:635–49.