OSTEONECROSIS OF THE HIP

Person's testimonial:

"About a year ago, I starting noticing a lot of groin pain, I started favoring my hip, walking with a limp. And it was not getting any better. So I needed to seek my physician on it, I felt like."

Osteonecrosis of the hip also known as avascular necrosis, is a disease affecting the blood supply of the bones, leading to the breakdown of the hip joint. While osteonecrosis can affect other joints, such as the knee or ankle joints, most cases, more than 90%, involve the hip.

The human hip, like the shoulder, is a ball and socket joint, in which the ball of one bone, the femur, or bone of the upper leg, fits into the socket of the pelvic bone. As the most flexible, free moving joint in the body, the normal hip can move backwards and forwards, from side to side, and can perform twisting motions.

Like other free moving or synovial joints, the hip contains a small amount of fluid, which lubricates the joint whenever it moves. It is held together with ligaments, straps of tough, sinewy tissue, which help prevent the joint from dislocating. Full function of the hip joint depends on the successful coordination of many interrelated parts, including bones, muscles, tendons, ligaments, and nerves. Bone is living tissue, requiring the nourishment of a regular vascular supply. When the blood supply to the head of the femur is interrupted, a section of the bone dies.

Osteonecrosis sometimes occurs when a fracture at the neck of the femur damages the bone, interrupting the nutrient supply. Another traumatic cause may be a dislocation of the hip joint, in which the ball and socket bones are forced out of position. It is important to note that minor injuries will not cause osteonecrosis and even most major traumas will not result in the condition.

Osteonecrosis may also be the end result of a number of medical conditions that gradually undermine the health of the bone. These include lupus, kidney and liver disease, sickle cell anemia, and blood clotting disorders. Excessive intake of alcohol, long term use of cortical steroids drugs, or local radiotherapy also increase the likelihood of the disease.

Whether osteonecrosis is caused by an injury or due to an existing medical condition, the symptoms and course of the disease are similar. In its early stages, osteonecrosis may not show symptoms at all. The most common, early symptom is groin pain. Stiffness and limping are very common indicators of the disease.

Person's testimonial:

When the pain didn't go away, I decided to see my family physician and he, in turn, sent me to the orthopedic surgeon. And he took some x-rays and did an examination and said that I have avascular necrosis of my hip.

Unfortunately, osteonecrosis has usually advanced by the time most people experience symptoms. The longer the disease has progressed without detection, the harder it is to treat and save the hip joint. X-rays do not reveal the earliest stage of osteonecrosis. Once the condition has advanced, x-rays show damage to the bone and reveals such findings as the collapse of the femoral head.

Magnetic resonance imaging, or MRI scans- which show changes in tissue, reveal earlier signs of osteonecrosis. Because of this, patients with unexplained groin pain, despite a normal hip x-ray, may need an MRI of the hip. If the femoral head remains intact, and there is no arthritis, the bone can often be treated with a salvage procedure, delaying the need for total joint replacement.

The prognosis for osteonecrosis is much more hopeful if the condition is detected in its early stages. Non-surgical treatment options include the use of walkers and crutches. These devices can help manage the pain while, at the same time, protect the joint until surgery. Non-steroidal anti-inflammatory medications are commonly used to help limit pain. Surgical options include core decompression. This is a simple procedure used in mild to moderate cases. A hole is created in the bone and a part of the bone is removed from the hip area. This has shown good, short-term results in providing pain relief in the early stages of the disease.

The use of crutches is necessary for six weeks after core decompression to avoid fracturing through the hole. Bone grafting; the dead bone is removed and a bone graft, taken from the patient or from a bone bank, is put in its place. Crutches and or walkers may need to be used for an extended period to help the healing process. Vascularized bone grafting; similar to bone grafting, the dead bone is removed and a bone graft, this time with its own blood supply, is put in its place.

When vascularized fibular grafts are carried out, teams of micro surgeons procure the graft from the lower leg, prepare the hip, complete the placement of the graft in the hip, and reestablish blood flow to the graft. Vascularized bone grafting is a reasonable procedure if the femoral head has not collapsed in a patient who is too young for a hip replacement. It is not recommended for patients over 50. Osteotomy; this procedure is used only in special cases.

The bone is cut below the affected area and turned so that another portion of the bone, one that is not affected by osteonecrosis, is the new, weight bearing area. If the patient is very young and the femoral head collapses, despite all efforts, osteotomy may be one more option before hip replacement. With extensive arthritis of the hip joint, or collapse of the femoral head, resurfacing or replacement are the only options.

Femoral head resurfacing; a metal head is placed over the original femoral head to provide a round surface and decrease pain. Over time, a complete hip replacement will need to be preformed. Femoral head replacement; the femoral head is replaced and a stem is placed inside the femoral bone.

Total hip replacement; once the disease has progressed to the point where the hip socket is affected, total hip replacement may be necessary. Hip replacements are usually successful. Because a total hip replacement may not last as long as the life of the patient, most surgeons try to wait to perform this operation until it is absolutely necessary.

Person's testimonial:

"The doctor's suggestion to me was to have a total hip replacement because of the rapid pace that my disease had taken in my hip. And on the day of my surgery, they took me in and I went under a general anesthesia and when I woke up several hours later, they did get me up and started on a walker."

The decision to have surgery to replace the hip joint is made depending on; the age of the patient, fitness for surgery, functional impairment of the patient, degree of pain and lack of response to medication, and the stage of hip joint disease.

Since osteonecrosis often occurs in people who are young, under the age of 40, the goal is usually to preserve the hip joint for as long as possible before resorting to total hip replacement. Patients need to be aware of the fact that revision surgery may be required after a number of years. Joint replacements cannot be expected to last forever.

Person's testimonial:

"From what the doctor told me, the hip implants do not last forever. And because of my age, that I'll most likely have to have a revision of this hip later on."

Hip replacement surgery is an elective procedure that is nearly always successful in improving the strength and decreasing pain in a disabled hip joint. As in the case of any surgical procedure, outcomes are dependent on the state of one's general health, including mental and emotional health.

Surgical outcomes are sometimes more complicated when there are multiple levels of degeneration cause by advanced disease or other medical conditions. Patients with sicklecellanemia, Aids, or those on renal dialysis are less favorable candidates for successful hip replacement.

Although this surgery is usually without any significant problems, there may rarely be medical complications, including respiratory or cardiac malfunction and blood clots in the legs and lungs. The procedure itself may be complicated by an infection, injury to nerves or blood vessels, fracture, weakness, stiffness or instability of the joint, pain, differences in limb length, or the need for additional surgeries.

Another complication that can occur is a dislocation. Moving the hip in certain ways can cause this and the patient will be taught proper precautions to prevent it.

Person's testimonial:

"After my surgery, then I had to go two to three times a week to physical therapy. The therapists worked with me on range of motion and the dos and don'ts of a total hip."

Commitment to rehabilitation is a key part of the process, as improvement to the hip joint is determined not only by surgery, but also by rehabilitative effort.

Person's testimonial:

"It's been about a year now and my surgery success rate was really good. I would do this again. It's returned me back to my daily activities and now I am able to live my life normally again, without pain."

DynoMed.com, LLC, as the executive producer of this videotape, does not practice medicine, does not recommend this or any other surgical technique for use on a specific patient, and does not guarantee the results of any particular surgical technique. Each patient should consult a physician for determining the necessity of surgery, and for the determination and utilization of the appropriate surgical techniques.

Images from LifeArt®, 3D Super Anatomy, 1998
Lippincot, Williams, and Wilkens

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