The hip joint is a “ball and socket joint” made up of the femur (thigh) bone and the acetabulum (pelvis). The head of the femur (ball) has a smooth surface on the end and when healthy provides a smooth glistening cushion (cartilage) and allows the hip joint to glide smoothly. The joint is supported by muscles that help provide stability and motion.
Arthritis is a disease that affects the surface of the joint (cartilage). Damaged cartilage causes a roughened surface and may lead to a clicking and catching sensation with persistent pain and limited range of motion.
There are three common types of arthritis:
Osteoarthritis or Degenerative Joint Disease is the most common type of arthritis, which is a slow progressive disease that wears down the cartilage. The normally smooth surface of the joint becomes roughened and may cause increased pain, stiffness, and limited motion.
Rheumatoid arthritis or Inflammatory arthritis is a systemic process that may involve multiple joints at the same time. Rheumatoid arthritis may affect people at any age and often is treated with very specific medications. The symptoms vary somewhat as pain usually worsens after periods of rest and inactivity as joints stiffen. Some may experience pain, swelling, redness and warmth, especially in the morning.
Post-traumatic arthritis may occur following an injury to the ligaments, cartilage, and bone that causes instability to the joint and leads to increased wearing of the cartilage surfaces.
The hip joint may develop cysts, bone spurs or loss of cartilage. The absence of cartilage will cause friction and narrowing of the normal joint space.
Symptoms may include an aching pain in the groin area, outer thigh and buttocks, and joint stiffness and reduced range of motion (difficulty putting on shoes and socks). The stress placed on the hip cartilage may increase pain symptoms and reduce activity levels. Inactivity can lead to weakened muscles that control the hip joint and further reduce the ability to perform daily activities.
The likelihood of arthritis increases with a family history and advancing age. Patients who are overweight and those who have undergone trauma to the hip joint may also experience increased wearing out of cartilage.
Fig. 1: While the image on the left shows the healthy anatomy of the hip, the image in the center details the various signs of arthritis. The image on the right displays a total hip implant and its placement within the hip and upper thigh. Click on each image to view a larger, more detailed version.
It is difficult to predict the timing and progression of the arthritic condition. Sometimes pain increases and the ability to participate daily activities decreases despite non-surgical treatment plans. In those cases, a total hip replacement surgery may be recommended.
Total Hip Replacement Surgery
The artificial joint or prosthesis replaces the damaged bone with a new joint composed of an artificial ball connected to a stem which is inserted into your thigh bone.
An artificial socket or bowl-shaped cup will replace the worn out socket. All of the new parts create a smooth contact surface designed to mimic your healthy joint to provide greater range of motion, improving your function and quality of life.
There are many types of hip replacements that use different materials. Some are metal on metal, metal on plastic, or ceramic. Your surgeon will discuss various options and help determine the best choice and most appropriate one for your individual needs.
Your surgeon will discuss your condition and treatment plan. For any questions regarding the above information please feel free to contact the HSS Patient Education Programs at 212.606.1263.