Definition
The hip joint attaches the leg to the torso of the body. In the hip joint, the head of the thighbone (femur) swivels in a socket, called the acetabulum that is made up of pelvic bones. While many causes of hip pain can arise from the joint itself, there are numerous structures surrounding the hip that can also be the source of pain.
Trauma is often the cause of hip pain, but any source of inflammation may cause pain in the hip area. Pain is one of the symptoms of inflammation, along with swelling, warmth, and redness; together these are signals that a problem may exist.
Causes
Pain can arise from structures that are within the hip joint or from structures surrounding the hip. The hip joint is a potential space, meaning that there is a minimal amount of fluid inside it to allow the femoral head to glide in the socket of the acetabulum. Any illness or injury that causes inflammation will cause this space to fill with fluid or blood, which stretches the hip capsule and results in pain.
The femoral head and the acetabulum are lined with articular cartilage that allows the bones to move within the joint with less friction. Also, the socket area of the acetabulum is covered with tough cartilage called the labrum. Just like any other joint cartilage, these areas can wear away or tear and become the source of pain.
There are thick bands of tissue that surround the hip joint, forming a capsule. These help maintain joint stability, especially with movement.
Movement at the hip joint is possible due to the muscles that surround the hip and their tendons that attach across the hip joint, allowing motion in different directions. Aside from controlling movement, these muscles act in concert to maintain joint stability. There are large bursas (closed fluid-filled sacs) that surround areas of the hip and allow the muscles and tendons to glide more easily over bony prominences. Any of these structures can become inflamed.
Pain from other sources can be referred to the hip, meaning that while the hip hurts, the problem may potentially originate elsewhere. Inflammation of the sciatic nerve as it arises from the spinal cord in the back can cause hip pain, especially if the L1 or L2 nerve roots are involved. Other types of nerve inflammation may manifest as hip pain, including pain arising in the lateral femoral cutaneous nerve of the thigh, which is often inflamed in pregnancy. Pain from an inguinal hernia may also cause pain that is felt in the hip.
Hip pain is a nonspecific complaint that requires the health-care practitioner to find the underlying cause, from injury to illness. Without specific trauma, the approach to the diagnosis of hip pain requires an open mind.
Treatment and Prevention
Self-Care at Home
As we age, the body tends to tolerate falling less easily. Falls often can cause contusions (or bruising) and inflammation of the tissues that are damaged. This pain may not be felt immediately, and the injured area may begin to stiffen and get sore over a few hours. If the patient can stand and walk relatively easily with minimal limp, then it is reasonable to rest and ice the injured areas and begin activity as tolerated. Over-the-counter pain medications (acetaminophen [Tylenol], ibuprofen [Advil], naproxen [Aleve]) may be used. Crutches, a cane or a walker may be useful in the short term but these needs to be fitted to the patient’s height and some people may need training to use them properly. Usually, the pain and stiffness will resolve over a few days. If the pain persists or starts to worsen instead of getting better, medical evaluation may be helpful.
Hip pain and soreness that develop because of overuse but without any specific injury may be cared for at home with rest and gradual return to full activity. While rest is important, it is also important to maintain range of motion, meaning that attempts should be made to stretch the leg, hip, and back and keep the whole body moving.
Care for hip pain that exists because of an underlying medical condition should be coordinated with the health-care practitioner. Often, the hip pain will be episodic, depending upon the control of the medical condition.
The cause of the hip pain will direct the treatment provided.
Aside from medications, therapy will be directed to maintain the strength and range of motion of the hip. As with any illness or injury, the goal is to return the patient to their normal level of function. A team approach involving the health-care practitioner, physical therapist, or chiropractic care provider may be considered.
The body is a machine that needs to be well looked after over a lifetime. By maintaining a normal body mass index and avoiding obesity, providing a good diet to build strong bones, and by exercising routinely to preserve normal range of motion of the hip, osteoarthritis of the hips and back pain may be avoided.
Medications that prevent osteoporosis in women should be considered to minimize the risk of hip and back fractures in at-risk women. These include calcium, vitamin D, and bisphosphonates (Actonel, Boniva, Fosamax). Bone mineral density screening may be a reasonable screening tool.
For older individuals, it is important to minimize the risk of falling and breaking a hip or sustaining other injuries related to a fall. Preventive measures include wearing good shoes with a good tread, using a cane or walker for stability if needed, and making certain that walking areas in the home are free of clutter, including slippery area rugs.
For individuals of all ages, it is important to maintain good strength, flexibility, and posture throughout life to allow the hip to move and function normally.