Ask The Doctors: October 2019
Q: I have arthritis in my hip. I had a corticosteroid shot two weeks ago, but it did not help. I have decided to have hip replacement surgery. How long do I have to wait after the steroid shot?
A: Joint replacement surgery for both the hip and the knee is an option for people with painful osteoarthritis that can no longer be alleviated with nonsurgical measures. Before choosing to undergo surgery, many people will try a corticosteroid injection to calm inflammation in the joint. This may help to relieve pain and allow people to continue to be active and exercise. The shots don't always work.
Corticosteroids are powerful anti-inflammatory medications. They suppress inflammation and pain, and they also suppress the immune system. If the immune system is weakened in any way, it can put you at increased risk for infections. A possible complication of any joint replacement surgery is infection. While this occurs only rarely, the risk is increased if the immune system is impaired. For this reason, people should wait to have joint replacement surgery after having a steroid injection until the immune system has had time to recover.
This has been investigated in several studies. A study published in The Journal of Arthroplasty (September 2016) found that the infection rate among people undergoing total hip replacement who had not received a steroid injection was 2%. Among those who had a steroid shot within three months of surgery, the rate was 2.8%. A study published in The Journal of Bone and Joint Surgery (January 2019) found an increased risk for infection with knee replacement surgery only when a steroid shot was given within three months before surgery. Therefore, it is generally recommended to wait at least three months.
Q: I know exercise is recommended for people with osteoarthritis, but can't too much exercise cause arthritis or make it worse?
A: Osteoarthritis is caused by the wearing down of cartilage (the cushioning substance that covers the ends of bones in joints, allowing for smooth movement). The exact reason cartilage deteriorates is not known. However, several factors that increase risk have been identified. These include obesity, injuries and some occupations that put excessive stress on joints. For example, osteoarthritis may affect people with jobs requiring a lot of kneeling and heavy lifting.
A possible link between exercise and osteoarthritis is less clear. Exercise is undoubtedly good for overall health, including for the heart, lungs, muscles, bones and brain. But could repeatedly applying heavy loads on joints from high-impact activities, such as running, damage cartilage in hips and knees? There is some conflicting evidence, but it does not appear as though exercise, including running, causes osteoarthritis. Some research suggests runners are less likely to have osteoarthritis in the knees.
For people who already have osteoarthritis, exercise is highly recommended to relieve pain and improve function. But the type and frequency of exercise matters. People with osteoarthritis in weight-bearing joints, such as the hips and knees, should avoid activities that overstress those joints. Low-impact aerobic exercises, such as bicycling, exercises in a pool and swimming, are preferable. Exercises to strengthen muscles and increase flexibility are also recommended. This can help to support joints and improve range of motion. We advise seeing a physical therapist who will design a specially tailored exercise program.