Hip Arthritis: Overview

Hip Arthritis: Overview

In general, osteoarthritis in any joint is a common orthopedic problem affecting up to 25% of the population over the age of 18. The generic term arthritis is inflammation of a joint causing pain and loss of motion. Different types of arthritis can be caused by autoimmune disease or by infection of a joint.

This video will focus on osteoarthritis of the hip, the wear-and-tear arthritis, when the cartilage simply wears down over time. Specifically, arthritis that occurs in the hip affects up to 10% of the population over 45 years old.

Just like the knee and ankle, the hip is considered a weight-bearing joint where it has to support anywhere from 2.5-3x a person's body weight with each walking step that is taken. Hip arthritis is typically seen more in females, Caucasians, and of course the aging population.

Since it develops over time, older people tend to have it more than young people do. But it is not just age that puts a patient at risk of developing hip arthritis. There are some studies that show larger patients putting extra weight on their joints can cause arthritis to develop, but others claim that body weight does not have any effect.

Unfortunately, there is not really a consensus one way or the other. However, it is known that a previous injury to the joint, such as a sports injury or a car accident, can increase the risk of developing arthritis. Also, someone who has femoroacetabular impingement or f A I, has a greater chance of having hip arthritis than someone who does not.

To understand a little more about arthritis of the hip, here is a quick look at the anatomy. There are many muscles that surround the hip joint to keep it stable and to move the entire leg while doing any type of physical activity.

Beneath the muscles, the hip is a ball and socket joint, where the femoral head at the top of the thigh bone is the ball and the acetabulum is the socket. There is a layer of smooth surface cartilage that covers the ball and makes the shape of a horseshoe in the socket.

This cartilage allows for smooth movement of the joint as well as cushioning when the patient is walking, running, or jumping. Over time, this cartilage can wear down, decreasing the amount of cushion in the joint as well as creating rough surfaces that rub against each other. This causes pain and limited movement of the hip.

If these symptoms become severe enough, a patient should have an evaluation done by an orthopedic healthcare provider to make sure they know what the problem is. At the doctor's office, the healthcare provider will take a full history of what has been going on and do a physical examination of the hip.

The provider will gather information from the patient to help make a diagnosis. This will include if there was any prior injury to the hip joint, how long the pain has been going on, any other existing medical conditions, and if there is a history of arthritis in the family. If mom and dad had arthritis, then their children have a higher chance of getting it as well.

Most patients who have pain from hip arthritis will say they have a pretty consistent dull, aching or throbbing pain in the front of their hip. At times they will have short episodes of sharp pain with certain movements and state that the pain nearly brought them to their knees.

During the physical exam, the provider will move the hip in certain directions, but the most common finding is a decrease in hip internal rotation. This motion is when the patient is seated with their knees hanging over the edge of the table. The provider rotates their thigh bone in by taking their foot and pulling it toward the outside.

Patients with hip arthritis typically have less motion and more pain with internal rotation when comparing it to the other hip. Sometimes hip arthritis can act like hip impingement, which is a different diagnosis. X-rays will be taken to confirm what the problem really is.

Here is an x-ray of a pelvis looking from the front showing normal hip joints. The space between the ball and socket is actually the layer of surface cartilage, but since cartilage cannot be seen on x-ray, it shows up as a space. The space means that cartilage is still there.

Here is an x-ray where the right hip has arthritis and the left hip is suffering from hip impingement. On the right hip, the top of the ball is worn down and flattened, and there is no space left between the ball and socket, which means the cartilage has worn away. There are also several bone spurs growing, indicating arthritis.

On the left hip, there is still some space between the ball and socket, but there is a bump of extra bone on the ball side. This is called a cam lesion, and it is probably hitting the edge of the socket when the patient moves their hip a certain way. This patient likely has pain in the same location in both hips, but the x-ray tells us that each hip has a different problem.

In the case of hip impingement, an MRI would be the next step in making a diagnosis. However, an MRI does not typically provide any extra information in the case of arthritis. Only in special situations would the provider order an MRI to take a closer look.

Once a diagnosis of hip arthritis has been made, the next step is determining what treatment to start with. The provider and the patient will discuss different treatment options to try and get the patient back to their daily activities with minimal pain.