Hip Arthritis and Hip Replacement
Written by: Timothy Lane, M.D.
Arthritis of the hip is a term that covers many painful conditions affecting the hip joint. Degenerative arthritis is the most common problem producing accelerated wear of the cartilage surfaces of the joint. Cartilage is a very smooth, low friction, cushioned surface. Wearing and thinning of the cartilage surfaces of the ball and socket joint produces inflammation, swelling, and pain. When this wear becomes severe with bone on bone surfaces in the joint, the pain produced often severely limits an individual’s ability to walk and perform many normal activities of daily living.
Rheumatoid arthritis and similar conditions produce an inflammatory arthritis. In an inflammatory arthritis the body’s immune system attacks the joint. This produces inflammation, and eventually destruction of the cartilage surfaces.
In avascular necrosis the blood supply to the femoral head is damaged. This results in an area of dead bone, often in the part of the bone under the most stress. This damaged bone is weakened and often will become cracked or deformed. This creates an irregular surface of the joint producing inflammation and pain.
Hip dysplasia is a condition where the socket part of the joint is shallower than normal. This results in a smaller area available for transmitting loads across the joint. The higher loads cause the smooth cartilage to wear away exposing the bone beneath the cartilage and producing pain.
An injury which damages the surfaces of the joint can also cause accelerated wear and early arthritis.
WHAT TREATMENTS ARE AVAILABLE?
The initial treatment of the pain caused by hip arthritis almost always involves non-surgical alternatives. Anti-inflammatory medications such as ibuprofen, naproxen and prescription anti-inflammatory medication can decrease the inflammation and pain caused by the arthritic process. Light non-impact aerobic exercise such as walking, swimming, bike riding, light gym exercises and stretching help maintain ones strength and flexibility and function. Moderate exercise does not damage the arthritic joint and can decrease pain in some individuals.
Weight control and at times weight loss are extremely important. Individuals who are near their ideal body weight have a much slower rate of wear of their joint and tend to experience less pain in their arthritic joint. This is probably because of the lower loads on the damaged joint.
Many people with a painful hip joint find themselves becoming less active because of their pain. This lower activity level can dramatically decrease the calories an individual burns. Hip arthritis patients need to carefully monitor their weight and caloric intake to avoid weight gain and the increased pain and decreased function associated with this.
Mild and at times stronger pain medications can make hip arthritis more bearable.
Walking aids function by decreasing load on painful hip joint. A cane or at times a walker can often improve an individual’s ability to walk distances with their painful joint.
WHEN IS SURGERY APPROPRIATE?
Typically this is when someone has severe and disabling hip pain, and medications, walking aids, and physical therapy are no longer providing an acceptable level of pain relief.
WHAT TYPE OF SURGERY IS DONE FOR HIP ARTHRITIS?
Patients with a severely arthritic hip have their hip joint replaced with a new ball and socket joint called a total hip replacement. This device replaces the worn out bearing surface of the hip with a new bearing surface. The new hip joint is made of titanium because this is a metal that the bone bonds to well. The bearing surfaces of the new joint are usually made of a cobalt chrome (stainless steel) ball against a durable high density polyethylene (plastic) liner in the cup. Less frequently used bearing surfaces include metal on metal bearings and ceramic on ceramic bearings. Currently much of the research and progress in hip replacement surgery is focused on improving the longevity and safety of these bearing surfaces.
HOW IS THE SURGERY PERFORMED?
Hip replacement surgery is performed through an incision placed over the hip joint. The surgeon approaches the hip joint either through the back (posterior), side (lateral or anterior-lateral), or front (anterior) aspect of the joint. The choice of a hip approach is made on multiple factors including surgeon experience, published results in the medical literature, safety, the ability to recognize and handle problems as they arise during surgery, incision appearance and length, and the effect of the approach on rehab. Over the last 5-10 years surgeons have been re-thinking how to perform these approaches to the hip. All three approaches have been significantly modified to provide less tissue trauma, improved incision appearance, improved hip stability, and more rapid rehab. The most commonly used approach in 2009 is the posterior approach. This includes surgeons at major medical centers as well as practicing orthopedic surgeons in the community.
Most orthopedic surgeons feel that all three approaches (posterior, lateral or anterior-lateral, and anterior approaches) provide excellent results, and there is not a clear or overriding advantage to one approach.
WHAT WILL MY REHAB INVOLVE?
Currently hip replacement requires a 2-4 day hospital stay. Physical therapists in the hospital teach patients how to perform activities of daily living with their new hip. The patient is discharged home when they are independent in physical therapy and are otherwise medically stable. At home a physical therapist visits patients 2-3 days a week the first several weeks to instruct in home exercises and how to do activities of daily living. Speed of recovery and how fast to let people get back to their normal activities is another area of debate in the hip surgeon community. Patients obviously want to get back to normal as quickly as possible, but are most concerned about achieving a durable, long lasting result at the least possible risk. The newer operative techniques do potentially allow more rapid rehab and most surgeons are letting their patient’s progress with their activities faster than in the past. Recently reports in the orthopedic literature of higher complications rates with more rapid rehab protocols have caused many surgeons to ask their patients to allow more time for healing in their initial post op period.
Today patients with medical problems are barraged with information on different options available for their care. Drug and equipment companies, and at times their medical providers, advertise their product is the best and suggest that the patient request this from their doctor. Orthopedic surgeons receive much of their current information from attending medical meetings, reading the published orthopedic literature, reviewing promotional literature from companies, and from discussion with their colleagues. Although there are areas of controversy in hip surgery, looking at what orthopedic surgeons choose to do is a valuable guide to what these surgeons feel serves their patients best.
In summary, the advances that have occurred over the last several years in hip surgery can provide hip arthritis patients with dramatic and durable improvements in their quality of life.