Injections into the knee may be helpful in patients with knee osteoarthritis.
Hyaluronic acid injections
Hyaluronic acid is what is called a viscosupplement - a product that can be injected to improve lubrication within the knee cavity. There are several hyaluronic acid-based products on the market.
Patients with a knee effusion related to osteoarthritis should have the effusion aspirated prior to injecting any hyaluronic acid preparations to maximise effectiveness. Some patients may benefit from injection with an intra-articular steroid a week or two before the hyaluronic acid to allow the steroid to have a positive effect on effusion reduction.
Viscosupplementation for Osteoarthritis: a Primer for Primary Care Physicians. Reid MC. Adv Ther. 2013 Nov; 30(11): 967–986.
Appropriate Use Criteria for Hyaluronic Acid in the Treatment of Knee Osteoarthritis in the United States. Bhadra AK et al. Cartilage. 2017 Jul; 8(3): 234–254.
Corticosteroid injections such as triamcinolone are often given into the knee joint in arthritic patients who are suffering from pain related to inflammatory synovitis. Such injections seem to have early benefits - probably by reducing the synovitis - but repeated injections every few months may lead to damage to the joint cartilage and a worsening of the arthritis.
There are also questions about patients who plan to go onto total knee replacement as a certain time is recommended after a steroid injection in case the steroids diminish healing of the knee replacement.
Effect of Intra-articular Triamcinolone vs Saline on Knee Cartilage Volume and Pain in Patients With Knee Osteoarthritis. McAlindon TE, LaValley MP, Harvey WF, Price LL, Driban JB, Zhang M and Ward RJ. JAMA. 2017 May 16; 317(19): 1967–1975.
Platelet rich plasma (PRP) treatment can be beneficial for degenerative joint damage and has been proven to temporarily relieve pain and function of the involved joint.
PRP for Degenerative Cartilage Disease: A Systematic Review of Clinical Studies. Laver L, Marom N, Dnyanesh L, Mei-Dan O, Espregueira-Mendes J and Gobbi A. Cartilage. 2017 Oct; 8(4): 341–364.
Clinical Update: Why PRP Should Be Your First Choice for Injection Therapy in Treating Osteoarthritis of the Knee. Cook CS and Smith PA. Curr Rev Musculoskelet Med. 2018 Dec;11(4):583-592. doi: 10.1007/s12178-018-9524-x.
Stem cell injections
It is now fairly routine to treat circumscribed joint cartilage lesions with cells multiplied in a laboratory and embedded in a matrix which covers the defect. Injection of a liquid solution of cells is a very different concept and, although this is being performed in many clinics, the jury is still out as to the efficacy compared to the cost. A current popular concept is that of injecting microfragmented fat obtained from the patient's belly or thighs, and which contains pluripotential cells called pericytes.
Intra-articular injection in the knee of adipose derived stromal cells (stromal vascular fraction) and platelet rich plasma for osteoarthritis. Bansal H, Comella K, Leon J, Verma P, Agrawal D, Koka P and Ichim T. J Transl Med. 2017; 15: 141.
Current perspectives in stem cell research for knee cartilage repair. Orth P, Rey-Rico A, Venkatesan JK, Madry H and Cucchiarini M. Stem Cells Cloning. 2014; 7: 1–17.