The hip is the largest ball-and-socket joint in the body. The ball-shaped head of the femur (thigh bone) fits into the cup-shaped acetabular socket (hip socket). In a healthy hip, both the femoral head and the socket are lined with a thin layer of cartilage that cushions the bones and prevents them from rubbing against each other. The rim of the socket is also lined with labrum, which is an additional layer of cartilage that secures the femoral head in place.
During movement, if the head of the femur makes abnormal contact with the hip socket, it can cause pain and the soft tissue to become pinched and compressed. Over time, impingement leads to irreversible cartilage damage and labral damage. It may also lead to osteoarthritis.
FAI affects people of all ages, including adolescents and young adults. In fact, the condition has been increasingly recognized as the cause of pain in young, active individuals. The symptoms of impingement are commonly seen in athletes, especially those who participate in baseball, soccer, lacrosse, golf, and other sports that involve repetitive hip rotation.
This article will help you understand the types of hip impingement that can occur, how the condition develops, how doctors diagnose the condition, and what treatment options are available.
Types of Hip Impingement
FAI occurs when an abnormality of the femoral head or the hip socket prevent normal movement. There are two main types of hip impingement:
Cam impingement occurs when the femoral head is not perfectly round and cannot rotate smoothly inside the acetabulum. It often results from a bump formed from excess bone growth at the end of the femur. During movement, the bump grinds the cartilage inside the acetabulum.
Pincer impingement occurs when the acetabulum is excessively deep or covers too much of the femoral head. In the case of the latter, it often results from excess bone growth that extends out over the normal rim. The overhang can impinge the neck of the femur and tear labrum.
When both conditions exist at the same time, it is called combined impingement.
The most common symptoms of FAI are:
- Pain in the hip, groin, or lower back
- Stiffness in the thigh, hip, or groin
- Inability to flex the hip beyond a right angle
Symptoms are typically mild at first and worsen over time. Pain will worsen both during activity (e.g. running, jumping, or turning) as well as during long periods of rest. If left untreated, hip impingement may lead to osteoarthritis.
People with hip impingement may not experience symptoms. In fact, it is possible for some people with an impingement to live active lives and never experience a problem. However, when symptoms do develop, it means that condition has already reached the point where cartilage or labrum has been damaged.
If you experience the symptoms of hip impingement, it is recommended that you talk to a hip specialist. Early treatment can not only help you relieve immediate pain and stiffness but also prevent further damage.
FAI is caused by either a structural abnormality that is present at birth or one that forms during adolescent development.
It is important to note that a structural abnormality alone will not cause impingement. The symptoms of impingement result from friction between the femoral head and the socket. The hip must be provoked in order for friction to occur. This is why athletes with a hip abnormality, especially those who repetitively use their hips, often experience impingement.
Non-surgical, non-invasive treatments are recommended for everyone with FAI. While these treatments do not resolve the underlying cause of the condition, they can help relieve symptoms and potentially slow the worsening of pain.
Limit or avoid activities that repeated rotate or flex the hip. This includes daily habits—such as sitting with your knees together, crossing your legs, or sleeping on your side—as well as many sports. If you must participate in sports that stress your hip, make sure to take periodic breaks and receive adequate rest between games.
Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)
Non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (e.g. Advil) or naproxen (e.g. Aleve) can help relieve hip pain caused by impingement. These over-the-counter medications inhibit prostaglandins in the body, which contribute to inflammation.
Corticosteroids are potent anti-inflammatory medications that can relieve pain when injected directly into the hip joint. Typically, a small amount of anesthetic is injected in addition to the corticosteroid. The anesthetic provides immediate relief that lasts a few hours while it may take two to three days for the corticosteroid to take effect.
Most patients experience some pain relief from corticosteroids. The relief can last for a few weeks to a few months. Injections are administered at regular intervals in order to lower the risk of side effects.
Physical therapy is a multi-pronged treatment that addresses your muscle strength, flexibility, joint mobility, posture, and gait (the way you walk). A comprehensive physical therapy program focuses on ways to relieve your pain, restore hip function, reduce stress on your hip, and avoid future injuries. Physical therapy should be a compliment to stretches and exercises that you perform on your own.
Surgery addresses the structural abnormality that causes FAI. Surgery may be performed in order to cut or remove bone tissue, remove loose pieces of the labrum, or to repair labral tears by reattaching the labrum to the bone.
Surgery can be performed either arthroscopically or with an open incision.
Arthroscopic Hip Surgery
Arthroscopic hip surgery is a minimally-invasive surgery in which an orthopaedic surgeon inserts a small camera, called an arthroscope, through a small incision in the hip. The camera feeds an interior view of the joint to a nearby video monitor. After the surgeon has clearly identified the problem, they will insert small surgical instruments through a separate incision in order to make the repairs. The surgeon can trim, reshape, remove, and stabilize the different components of the hip without fully exposing the joint. The surgery typically takes about two hours or less.
Candidates for arthroscopic surgery tend to be younger and in otherwise good health. Due to the nature of the surgery, patients typically return home within 24 hours of the procedure, experience less post-operative pain, and recover faster. Learn more about the advantages of an arthroscopic procedure.
Traditional Hip Surgery
Open surgery, also known as traditional surgery, begins a single long incision that is approximately 7 to 10 inches long. Next, certain muscles and tendons must be cut in order to access the upper thigh bone. Then, the femoral head is dislocated from the hip socket in order to expose all of the parts of the joint. The surgeon reshapes, removes, and stabilizes the different components of the joint, secures the femoral head back into the socket, and closes the incision. The open approach typically requires a few hours to perform.
A surgeon may recommend open surgery, also known as traditional surgery, if the patient is older or shows signs of hip arthritis prior to surgery.
- Detecting and Treating Femoroacetabular Impingement (FAI)
- Frequently Asked Questions about Hip Pain: Femoroacetabular Impingement (FAI)
- An Examination of Hip Labral Tears: Symptoms, Treatments, and Recovery
Talk to a Hip Specialist
Only an orthopaedist can properly diagnosis hip impingement. Dr. Steve Hamilton at Beacon Orthopaedics and Sports Medicine is a sports medicine physician and orthopaedic surgeon who specializes in hip treatments. Dr. Hamilton can conduct a full examination of your hip, provide an accurate diagnosis, and recommend the appropriate treatment. If you experience hip pain or stiffness of any kind, schedule an appointment with Dr. Hamilton today.