So when we think about osteoarthritis, we think about wear and tear of the joint. If you think about your car, the more you drive it, the more you use it, the more the parts start to wear. And ultimately, they fail. It's the same thing with hip joints and knee joints. As we age, we accumulate, wear and tear, we accumulate damage and that can lead to pain, stiffness, and functional problems in the joint. There have been a number of studies, linking body weight to osteoarthritis. So we do think that there's an association between weight and wear and tear on the joints, which is why we recommend weight loss for a lot of patients. Weight loss can not only help with the symptoms, but it's possible that it could potentially reduce the amount of wear and tear on the joint over time as well. We also see trauma as a factor in why patients ultimately develop osteoarthritis. Patients who have a significant injury to the hip joint, or a significant injury to the knee joint may damage the cartilage and that can lead to wear and tear and arthritis over time as well. Whether it's the hip joint or the knee joint, pain, stiffness, and functional problems are common presenting symptoms. So for many patients, it's a soreness that maybe doesn't go away, or it's sometimes it's a sharp pain that they notice with increasing frequency. We think in the adult hip joint, that subtle malalignment contributes to arthritis. If the hip joint, if the ball and socket is just slightly out of alignment, over time, that can lead to accelerated wear and tear. We do occasionally see some patients that have substantial deformity of their knee joint, which is troublesome or can lead to some functional problems. There may be an alignment issue as well. If the knees are slightly out of alignment that can lead to accelerated wear and tear. Ultimately for many patients, it gets to the point where they say that they need to do something about it and look into it. That's typically where we get an x-ray. So whether it's hip arthritis or knee arthritis, we always recommend that patients exhaust non-surgical options before considering joint replacement surgery. Non-surgical options are things like weight loss, over the counter medications, like Tylenol and anti-inflammatories, physical therapy, injections. Cortisone injections into the hip joint for many patients can relieve the symptoms substantially and allow them to continue to function and do what they need to do on a day-to-day basis. So non-operative measures are certainly the mainstay of treatment. It's only after those things have failed, that we start considering joint replacement.