Osteoarthritis of the hip is a painful condition that can interfere with leg movement and diminish the quality of life. In some, the symptoms are mild, but in others, osteoarthritis can be severe and can even lead to joint failure. Pain is often intermittent in early stages, but in later stages, the pain can be constant with periods of sharp, intense pain. The hip joint becomes stiff and unstable, making it difficult to move around and greatly increasing the risk of falls.
Unfortunately, there are few effective treatments for osteoarthritis of the hip. Management includes pain control with non-steroidal anti-inflammatory drugs and physical therapy. Steroid injections into the hip are not as effective as they are for knee osteoarthritis, so many doctors hesitate to perform them. Joint supplements such as glucosamine and chondroitin are unlikely to be very effective—clinical trials have not provided evidence that they actually work. The definitive treatment for hip osteoarthritis is hip replacement surgery, which is expensive and associated with a long period of recovery.
The main problem in osteoarthritis is that the joint breaks down over time from wear and tear (i.e. microtraumas). At the same time, the joint has a very limited capacity to heal itself. In other words, once the joint breaks down, it pretty much stays that way. Since life is a series of joint microtraumas, the hip gets progressively worse. Indeed, one in four people will have painful osteoarthritis of the hip by age 85, and hundreds of thousands will have it earlier in life.
Scientists have long wanted to find ways to help the body regenerate the joint substances, particularly joint cartilage. Unfortunately, the joint does not receive good blood supply and no known drug or supplement can actually rebuild joint cartilage. That is the main reason researchers are aggressively testing stem cells as a treatment for hip osteoarthritis.
Mesenchymal stem cells have the potential to become many different types of cells, including chondrocytes (cartilage cells). Mesenchymal stem cells sense the environment they are in and then become the cell consistent with that environment. So, the theory goes, injecting mesenchymal stem cells into the hip joint can prompt them to become hip joint cells (chondrocytes).
Researchers tested this hypothesis in a clinical study. They injected mesenchymal stem cells taken from fat tissue (i.e. adipose) and injected them into the hip joints of people with difficult-to-treat hip osteoarthritis. They compared the patients’ Harris Hip scores (HHS) before and 6 months after treatment. HHS is a reliable way to assess the severity of osteoarthritis symptoms. An HHS score of less than 70 is “poor” and a score of 80 to 90 is “good.” Before stem cell treatment, patients had an average HHS score of 67.2±3.4 and 84.6±6.3 afterward. Scores also improved in other tests including WOMAC and Visual Analogue Scale. In other words, mesenchymal stem cell treatment reduced pain and improved joint function in these patients compared to levels prior to treatment.
The authors of the clinical study state that “preliminary results are positive and promising.” Further research and studies will help to learn more about this regenerative medicine potential.
Reference: Dall’Oca, C. et al. (2019). Mesenchymal Stem Cells injection in hip osteoarthritis: preliminary results. ACTA Biomedica. 2019, 90(Suppl 1): 75-80.