Anatomy of the Hip
An inside look at the structure of the hip.
One of the body's largest weight-bearing joints, the hip is where the thigh bone meets the pelvis to form a ball-and-socket joint. The hip joint consists of two main parts:
- Femoral head – a ball-shaped piece of bone located at the top of your thigh bone, or femur
- Acetabulum – a socket in your pelvis into which the femoral head fits
Bands of tissue, called ligaments, connect the ball to the socket, stabilizing the hip and forming the joint capsule. The joint capsule is lined with a thin membrane called synovium, which produces a viscous fluid to lubricate the joint. Fluid-filled sacs called bursae provide cushioning where there is friction between muscle, tendons and bones.
The hip is surrounded by large muscles that support the joint and enable movement. They include:
- Gluteals – muscles of the buttocks, located on the back of the hip
- Adductor muscles – muscles of the inner thigh, which pull the leg inward toward the opposite leg
- Iliopsoas muscle – a muscle that begins in the lower back and connects to the upper femur
- Quadriceps – four muscles on the front of the thigh that run from the hip to the knee
- Hamstrings – muscles on the back of the thigh, which run from the hip to just below the knee
Major nerves and blood vessels also run through the hip. These include the sciatic nerve at the back of the hip and femoral nerve at the front of the hip, and the femoral artery, which begins in the pelvis and passes by the front of the hip and down the thigh.
Hip Pain Causes
Common and some not-so-common injuries of the hip joint.
The hip is prone to several types of injuries. Sometimes these happen in otherwise healthy joints – an automobile accident or fall breaks a bone or forces the femoral head out of its socket, for example. In other cases, joints compromised by congenital deformities or osteoporosis, for example, leave the hip vulnerable to injury upon the slightest trauma. The following are some of the more common hip injuries.
Broken hip. A broken hip, or hip fracture, can occur at any age, but they are most common in people age 65 and older, particularly women, with osteoporosis. In a younger person with healthy bones it may take a serious injury, such as a car accident, to break a hip, but when osteoporosis weakens bones, even a minor fall can result in a fracture.
Bursitis. Bursitis is swelling and inflammation of the fluid-filled sacs – the bursae – that cushion and lubricate the joints. Inflammation of a bursa situated between the bony bump on the side of the hip (the greater trochanter) and the tendon that passes over it causes pain and aching in the hip and on the outside of the thigh. Referred to as trochanteric bursitis, it is aggravated with walking or any activity that causes the tendon to move over the bone.
Dislocation. A dislocation occurs when the ball at the top of the femur slips out of the socket, causing severe pain and inability to move the leg. It usually takes a strong force – from an automobile accident or severe fall, for example – to cause a dislocated hip. Being born with a shallow hip socket or hip displasia (a congenital deformation of misalignment of the hip joint), however, makes dislocation more likely. Often the ligaments about the hip are damaged if a hip becomes dislocated.
Labral tear. A hip labral tear is damage to the cartilage that surrounds the bony edge of the socket in the pelvis. This can occur as the result of repetitive use of the hip and can be seen in the early stages of osteoarthritis or can be caused by an injury such as a fall or accident that causes twisting of the joint.
Snapping hip syndrome. This condition is characterized by a snapping sensation in the hip, with or without an audible noise and pain, when the hip is extended. Snapping hip syndrome may occur when bands of connective tissue that support the hip thicken and catch as they slide back and forth across the top end of the femur. Often, the bursae underneath also become inflamed and painful. Snapping hip syndrome may occur in athletes such as ballet dancers, gymnasts, runners, weightlifters and soccer players due to be the result of repetitive, vigorous use and injury.
Arthritis and Diseases that Affect the Hip
From cartilage breakdown to muscle inflammation, problems to blame for painful hips.
Many forms of arthritis and related conditions that affect the joint, muscles and/or bones can cause hip problems like pain, stiffness and swelling.
Here are some possible disease-related hip problems.
Osteoarthritis (OA). The most common form of hip arthritis, osteoarthritis is a chronic condition characterized by the breakdown of the cartilage that cushions the ends of the bones where they meet to form joints. In hip osteoarthritis, the cartilage that lines the acetabulum and/or covers the surface of the femoral head breaks down causing the bones to rub against each other. This may result in pain, stiffness, the loss of movement and the formation of bony overgrowths called spurs. Pain from hip osteoarthritis is often felt in the groin area and front of the thigh. Stiffness may be worst after periods of inactivity.
Rheumatoid arthritis (RA). Rheumatoid arthritis is a chronic inflammatory disease of the joints that occurs when body’s immune system – which normally protects us from infection – mistakenly attacks the synovium, the thin membrane that lines the joints. Symptoms of hip rheumatoid arthritis include pain, redness, swelling and warmth of the affected hip joints. Unchecked, inflammation can lead to hip joint damage loss of function and disability. In addition to the hips, rheumatoid arthritis commonly affects the knees, hands, wrists, feet, elbows and ankles.
Juvenile arthritis. Juvenile arthritis is the term used to describe arthritis when it begins before age 16. There are several different types of juvenile arthritis. Many can cause hip joint pain and swelling.
Ankylosing spondylitis. Ankylosing spondylitis is a form of arthritis that primarily affects the spine, causing inflammation in the spine that can lead to chronic pain and stiffening of the spine. Often other joints are affected. Aside from the spine, the hip is the joint most commonly affected by ankylosing spondylitis.
Lyme disease. Lyme disease is an infectious disease characterized by a skin rash, joint swelling and flu-like symptoms. The disease is caused by the bite of a tick infected with a bacterium called B. burgdorferi. Lyme disease can affect the hip.
Lupus. Lupus is a chronic autoimmune disease, meaning the body's immune system creates antibodies that attack and damage healthy tissues. Lupus can cause inflammation of the joints, including the hip, as well as the skin, heart, lungs, and kidney.
Gout. Gout is a form of arthritis that occurs when excess uric acid, a bodily waste product circulating in the bloodstream, is deposited as needle-shaped monosodium urate crystals in tissues of the body, including the joints. For many people, the first symptom of gout is excruciating pain and swelling in the big toe – often following a trauma, such as an illness or injury. Subsequent attacks may occur off and on in other joints, primarily those of the foot and knee. Gout less commonly causes hip pain.
Psoriatic arthritis. Psoriatic arthritis is a form of arthritis accompanied by the skin disease psoriasis. The skin disease often precedes the arthritis; in a small percentage the joint disease develops before the skin disease. The arthritis can affect both large and small joints, including the hip.
Infectious arthritis. Also called septic arthritis, infectious arthritis refers to arthritis that is caused by an infection within the joint. Infectious arthritis is often cause by bacteria that spread through the bloodstream to the joint. Sometimes it is caused by viruses or fungi.
Polymyalgia rheumatica. An inflammatory disorder that causes widespread muscle pain and stiffness, polymyalgia rheumatica mainly affects the neck, shoulders, upper arms, thighs and hips. The disease often comes on suddenly and resolves on its own in a year or two.
Osteonecrosis. Also called avascular necrosis or aseptic necrosis, this condition occurs when diminished blood to an area of bone causes it to die and eventually collapse. Blood flow may be blocked due to a number of causes including a clot, blood vessel inflammation or use of corticosteroid drugs. The hip is one of the most commonly affected joints.
Paget's disease of the bone. Paget’s disease is a chronic disorder in which excessive breakdown and formation of bone causes the bones to become enlarged, misshapen and weakened. The disease usually does not affect the entire skeleton, but just one or a few bones. If the pelvis is affected the disease can cause hip pain.
Sciatica. This is inflammation of the sciatic nerve. The largest nerve in the human body, the sciatic nerve runs from the lower part of the spinal cord, through the buttock and down the back of the leg to the foot. The most common causes of sciatica include compression of the nerve where it exits the spine by a herniated disc, or a rupture of one of the structures that cushions the vertebrae in the spine. Sciatica may be felt as a sharp or burning pain that radiates from the hip.
Why Your Hip Hurts
Learn more about three common causes of hip pain: osteoarthritis, tendinitis and bursitis.
When you have hip pain, you just want it to stop. But hips hurt for a variety of reasons that may require different remedies. Here’s a quick guide that will help you know what you can do to feel better at home and when it’s time to hobble to your doctor.
What is it? Cartilage, the spongy tissue that cushions joints, deteriorates, causing bones to rub against each other.
Where is the pain? It is usually in the groin, but you can also feel pain in the buttocks.
How is it diagnosed? The doctor will test your hip’s range of motion; loss of range is an arthritis tip-off. He’ll likely then take an X-ray, says Calin Moucha, MD, associate chief of joint replacement surgery at Mount Sinai Medical Center in New York City. “It could show joint-space narrowing, bony spurs and cysts in the bone.”
Home treatments. Don’t overdo activities, but don’t prop your feet up either, says Dr. Moucha. “Keep your joints in motion with low-impact activities like swimming, biking and walking.” Take nonsteroidal anti-inflammatory drugs (NSAIDs) such as naproxen (Aleve) or ibuprofen (Advil), according to label instructions for pain.
When to see a doctor. Call the doctor if the pain worsens and if over-the-counter measures like NSAIDs don’t help.
What is it? Tendinitis is inflammation of the band of tissue that connects muscles to bones and is often caused by overuse, says Dr. Moucha.
Where is the pain? If it’s hip tendinitis, you’ll feel a dull, deep ache in your groin, especially when you climb stairs or rise from a chair. If you have hamstring tendinitis, you’ll be smarting in the buttocks, says Peter J. Millett, MD, an orthopaedic surgeon at Steadman Clinic in Vail, Colo.
How is it diagnosed? Your doctor may ask you to lie down, bring your knee to your chest, and then push your knee against his resisting hands. “If that causes groin pain, it’s probably tendinitis,” says Dr. Moucha, especially if X-rays don’t show joint damage that would indicate osteoarthritis.
Home treatments.Stop doing what hurts and rest the tendon. Take NSAIDs and apply ice to the spot that hurts for 20 minutes several times a day.
When to see a doctor. If the pain doesn’t respond to ice and NSAIDs, or if you can’t put weight on your leg, it’s time to get help. Also see a physician if you feel pain at night.
What is it? Bursitis is inflammation of the bursae, sacs of lubricating fluid that cushion tendons.
Where is the pain? It’s burning the side of your hip.
How is it diagnosed? You’ll yelp when the doctor presses the sore spot.
Home treatments. Take NSAIDs, apply ice several times a day and give the area a rub. “One theory is that the bursa doesn’t get a great blood supply, so increasing it [through massage] helps healing,” says Dr. Moucha. And several times a day, stretch your iliotibial band, the fibrous tissue on the outside of the hip, which can also become inflamed. Standing up, cross your legs and touch your toes, holding for 20 to 30 seconds. Switch legs.
When to see a doctor. If you’re smarting after two weeks, the pain gets worse, you can’t stand or you have night pain, then head to the MD.
Hip Pain Diagnosis
Diagnosing Hip Problems
From blood work to X-rays, tests your doctor uses to find the cause of your hip pain.
Diagnosing a hip problem begins with a physical exam and medical history.
During the medical history your doctor will ask you questions, such as:
- What symptoms are you experiencing?
- Are your symptoms worse after activity or rest?
- Are there certain activities that make them worse – or better?
- How long have you been experiencing hip symptoms?
- Did you recall having an illness or accident around the time your symptoms began?
- Are you experiencing symptoms in any joints besides the hip(s)?
- Do any of your family members have arthritis or other hip problems?
- Do you have other medical problems that could be causing your symptoms?
During the physical exam your doctor will look at and touch your hip and other joints, if you are experiencing any problems with joints besides your hip joint. Your doctor will be looking for areas that are tender, painful or swollen, as well as indications the joint may be damaged. Your doctor also may ask you to stand up and move your hip joint. This will show the range of motion on your hip or how well you can move it. Depending on the findings of the history and exam, your doctor may order lab tests or imaging tests to help make or confirm the diagnosis.
Imaging Tests for Hip Pain
Tests that allow your doctor to get a picture of your hip.
Imaging tests can allow your doctor to see inside your hip joint – painlessly. The most common imaging tests to diagnose hip arthritis and other problems are:
X-ray (radiography). A standard X-ray is a simple test in which an X-ray beam (a form of electromagnetic radiation) is passed through the hip to create a two-dimensional picture of the bones that form the joint. Your doctor can use X-rays to view:
- Joint alignment. Problems with alignment can cause or worsen changes that result from arthritis in the hip.
- Joint space. Narrowing of the space between the two bones, which are normally covered by cartilage, can be a sign of arthritis and its severity.
- Bone spurs. Bony overgrowths at the joint are a sign of osteoarthritis.
- Bone structure. Problems of the bone, including fractures, osteonecrosis and Paget's disease of the bone can often be seen on X-ray.
Learn more about x-rays from the Radiological Society of North America.
Computerized axial tomography (CAT) scan. Also called a computed tomography (or CT) scan, this noninvasive test combines X-ray equipment with sophisticated computers to produce multiple images of the hip. The computer can combine the individual images to create a three-dimensional view of the hip. CT scan shows soft tissues such as ligaments and muscles more clearly than traditional X-rays do, so it is more useful for diagnosing certain hip problems.
Magnetic resonance imaging (MRI). This procedure uses a strong magnet linked to a computer to create a picture of the hip joint in black and white and shades of gray. Because an MRI shows the soft tissues as well as the bones, it is particularly useful for diagnosing injuries to the cartilage, tendons and ligaments as well as areas of swelling.
Learn how new MRI technology may enable early osteoarthritis diagnosis.
Lab Tests for Hip Problems
Tests that tell what's going on inside your body.
Often a sample of blood or joint fluid can help you doctor confirm a diagnosis. For example, a blood test showing high blood levels of rheumatoid factor – an antibody that acts against the blood component gamma globulin – or antibody called anti-cyclic citrullinated peptide antibody (anti-CCP) may suggest rheumatoid arthritis. High levels of antinuclear antibodies (ANAs), abnormal antibodies directed against the cells' nuclei, could suggest lupus or another inflammatory disease. A blood test that detects an immune response to the infectious agent that causes Lyme disease could be helpful in confirming a diagnosis of that disease.
Tests of fluid drawn from the joint with a needle may reveal crystals of uric acid, confirming a diagnosis of gout, or bacteria, suggesting that an infection is causing the joint inflammation.
Hip Pain Treatment
Hip replacement and other surgical options for hip arthritis and more.
When medications and other treatments don't keep hip pain at a manageable level, surgery to reposition or replace the hip joint may be the answer. Here are hip surgeries that may be worth pursuing.
Total joint replacement. The most common hip surgery is total hip replacement, a procedure in which the damaged hip is removed and replaced with a prosthesis of metal, ceramic and/or plastic components. The hip is the second most commonly replaced joint, after the knee. Hip replacement is an option when irreparable joint damage interferes with function and causes constant pain that is not alleviated by more conservative therapies.
Learn more about total hip replacement from the American Academy of Orthopaedic Surgeons.
Hip Resurfacing. For people who are young and active, hip resurfacing is an alternative to total hip replacement. Unlike total hip replacement, hip resurfacing doesn't require removing the femoral head and replacing it with a ball of metal or ceramic material. Instead the damaged femoral head is reshaped and fitted with a metal covering that fits into the socket.
Arthroscopy. Arthoscopy is a minimally invasive surgery performed by inserting a lighted scope and narrow instruments through small incisions in the skin over the joint. Arthroscopic surgery has been used for decades to correct knee problems; more recently it has been used on the hip to correct problems, such as labral tears. The usefulness of many arthroscopic procedures is controversial.
Osteotomy. Osteotomy is a major surgery in which damaged portions of the hip are removed and the joint is reshaped or repositioned to correct a deformity and/or improve alignment and function. An osteotomy may be appropriate for a person who has arthritis in a hip joint but is too young and active to be considered for hip replacement surgery.
Exercises to Strengthen the Hip and Relieve Pain
How exercise can help your hips, and moves you need to try.
Exercise is one of the best things you can do to help your hips. Exercise helps maintain range of motion and strengthens the muscles that support your hips. Stretching the muscles and tendons that surround the joint also can help ease pain from some hip problems and reduce the risk of some injuries.
Medications to Treat Hip Pain
What you need to know about the many medications used for hip problems.
Medications to ease pain, relieve inflammation, slow bone loss, modify the course of an inflammatory disease or prevent joint damage are an important part of treatment for many hip problems. The types of medications commonly used in treating hips are:
- Nonsteroidal anti-inflammatory drugs. Including more than a dozen different drugs, some of which are available without a prescription, nonsteroidal anti-inflammatory drugs (NSAIDs) are used to help ease arthritis pain and inflammation. They are used for all forms of arthritis and other painful hip problems. By far, most NSAIDs are taken orally. Recently, however, new topical preparations, such as Voltaren Gel and Pennsaid, have been approved.
- Corticosteroids. These quick-acting drugs, similar to the cortisone made by your own body, are used to control inflammation. If hip inflammation is due to a systemic autoimmunme disease, such as rheumatoid arthritis or polymyalgia rheumatica, your doctor may prescribe oral corticosteroids. If inflammation is limited to your hip or an inflamed bursa, your doctor may inject a corticosteroid preparation directly into the inflamed joint or bursa.
- Analgesics. Analgesics are among the most commonly drugs for many forms of arthritis, including hip arthritis. They may also be used to relieve pain from hip injuries and surgery. Unlike NSAIDs, which target both, pain and inflammation, analgesics are designed purely for pain relief. For that reason, they may be safe for people who are unable to take NSAIDs due to allergies or stomach problems, for example. When used as directed, they're also an appropriate, and possibly safer, choice for people whose arthritis causes pain but not inflammation.
- Disease modifying anti-rheumatic drugs. Disease-modifying anti-rheumatic drugs (DMARDs) are drugs that work slowly to modify the course of inflammatory disease. Different DMARDs may be useful for a number of different forms of arthritis of the hip including rheumatoid arthritis, lupus, ankylosing spondylitis and psoriatic arthritis.
- Gout medications. Some medications for gout are designed to reduce levels of uric acid in the blood to prevent future attacks of joint pain and inflammation. Others are designed to relieve the pain and inflammation of an acute attack. Many people with gout take both types of medication.
- Biologic response modifiers. The newest category of medications used for rheumatoid arthritis and a few other inflammatory forms of hip arthritis are the biologic agents. There are currently eight such agents approved by the Food and Drug Administration. Each blocks a step in the inflammation process without suppressing the entire immune system. In addition to rheumatoid arthritis, certain biologic agents may be used in juvenile arthritis, ankylosing spondylitis and psoriatic arthritis.
- Osteoporosis medications. Osteoporosis medications are those used to slow the loss of bone or help the body build new bone. Although they are not used specifically to treat hip problems, strong bones are less prone to fracture. Certain medications – called bisphophonates – in this category are also used to treat Paget's disease of the bone, which, rarely, is a cause of hip pain.
Ways to Prevent Hip Pain and Get Around
Sound waves, warm baths and other helpful tips and techniques for managing hip pain
Medications and injections don't always completely relieve hip pain. And if you have surgery, you'll likely need some help getting around while you heal. At times when you need extra help with pain relief or mobility, here are some techniques and devices worth trying.
- Canes. If placing weight on your hip causes pain, your doctor or physical therapist may recommend a cane. There are many different types of canes. The most common type has a single tip, but if you have trouble balancing, your doctor may recommend a quad, or four-point cane. Your doctor or physical therapist can advise the best way to use your cane, but generally you should hold it in the hand opposite the painful hip.
- Electrical Stimulation. Electrical stimulation of muscle tissue (called neuromuscular electrical stimulation) around the hip may be useful for strengthening the muscles that support the joint. Electrical stimulation may also increase blood flow to the tissues around the hip joint to relieve pain and promote the healing of injuries.
- Ultrasound. Ultrasound uses high frequency sound waves to stimulate the deep tissues within the body. It is believed that vibration of the sound waves stimulates deep tissues, to relieve pain, increase blood flow and, thereby, possibly promote healing.
- Cold and Heat. Warming tissues eases arthritis pain by increasing blood flow to affected areas, which can help decrease inflammation, relax tight muscles and eliminate waste products, such as lactic acid, that cause stiffness and soreness. Cold therapy, applied in the form of cold packs, ice packs, or fluids work by decreasing blood flow to reduce swelling, slowing the transmission of pain signals through nerves and inhibiting inflammatory chemicals. Cold application is also helpful to reduce pain, swelling and inflammation after an injury.
Preventing Hip Problems
Tips to prevent hip problems or progression.
While you can't prevent all hip problems, many of the same measures used to treat hip problems can reduce your risk or help prevent them from getting worse. Losing weight for example, may help keep hip osteoarthritis from progressing and proper exercise may help reduce pain and injury risk.
Taking measures to prevent injuries and tending to them promptly when they happen can prevent problems both now and down the road.
The following tips can help:
- Stretch and warm up before exercise. Cool down afterward.
- Don't overdo it. If you experience pain when exercising, stop and cool down.
- Wear properly fitting shoes.
- Avoid running on hard surfaces like asphalt and concrete when possible.
If you experience an injury to your hip, rest, elevate it and apply ice. If pain is severe or persists more than a day or two, call your doctor.
Weight Loss for Pain Hip Relief
Good advice for losing weight and how doing so can help your hips.
Maintaining a healthy weight – or losing weight if you are overweight – is good for your joints. Excess weight stresses the weight-bearing joints, such as the hip and knee, contributing to cartilage damage. In addition, fat cells are believed to produce inflammatory cytokines that contribute to arthritis.