Hip replacement surgery - also known as Total Hip Arthroplasty - has been one of the most important surgical
advances of this century. Today, more than 172,000 total hip
replacements are performed each year in the United States.
The hip joint is the second largest
joint of our bodies. When people think of the hip, they naturally
think of the buttock area. In anatomic terms, the hip joint
is actually the ball-and-socket joint where the thigh bone (femur) meets and articulates
with the cup-shaped socket formed by the pelvic bones (the
The top of the femur is shaped like a ball and is called
the femoral head. A healthy femur is covered with cartilage
and moves within the hip socket, which is also lined with cartilage. Together
the two articular cartilage surfaces are about a quarter of an inch thick
in a healthy hip joint. Articular cartilage accounts
for the clear space normally seen between the two bones on an x-ray of the
hip. This cartilage functions as both a shock absorber and a
low-friction surface that enables smooth gliding of the hip joint and
pain-free, unrestricted motion.
The various types of
arthritis damage the smooth gliding
surfaces of the hip joint, ultimately resulting in painful bone-on-bone
surface contact. Essentially, arthritis is the wearing down of
joint cartilage. While cartilage itself does not have nerve endings,
the bone of the femoral head and the acetabulum do, and these nerves get stimulated
(painful) when the bone surfaces rub together. As the the arthritis
progresses and the cartilage wears out, this hip pain becomes progressively
addition to the pain caused by cartilage wear, when the cartilage has worn to the point that bone surfaces
wear on each other, the body begins attempting to heal
the damage by creating new bone - in the form of bone spurs. Bone
spurs in the hip joint can cause additional pain, with grating or popping that can be felt and sometimes
Treatments for Hip Arthritis
In the early stages of
arthritis,there are non-surgical
treatments that can help manage hip discomfort.
Limiting activities that aggravate the hip (but without
Using a cane to decrease the force applied to the
Gentle exercises to maintain muscle tone and range of motion
Losing weight if obesity is a contributing factor
injections into the joint (a limited number times)
Drugs to decrease inflammation
These non-surgical treatments
can buy time before a hip replacement surgery is necessary. They can
make the arthritic hip less painful, and may slow the arthritic process.
However, they just treat the symptoms and not the cause.
surgery is a highly effective treatment for severe arthritis of the
hip. Hip replacement surgery is in reality a joint resurfacing
procedure. It eliminates pain and restores mobility by removing the
diseased bone and replacing worn out cartilage with a prosthesis
of man-made artificial materials.
Traditional hip replacement surgery
involves an incision of 10-12 inches over the back side of the hip and buttock.
This is called the posterior approach to hip replacement. The underlying muscles are split or cut to enable the surgeon to get to
the hip joint and resurface or replace it. The comparative
illustration at right shows the incision for a traditional hip
replacement in red.
Anterior approach hip replacement
surgery is a new development in the U.S. It is a tissue-sparing, minimally invasive technique, where the incision is made on the front of the hip, rather than the back. This allows a much shorter incision that gives access to the hip joint without detaching muscles from the pelvis or femur. The comparative
illustration at right shows the incision for an anterior hip
replacement in blue.
A special operating table is used, enabling accurate positioning and retention of pelvis and hips during the surgery, as well as allowing x-rays during the procedure to ensure precise placement of the new hip components. Specialized instruments are used to work
through the mini-incision in the natural interval between the muscles. The
arthritic surfaces are removed and replaced with new surfaces without disturbing the most important muscles for hip function, the gluteal muscles that attach to the pelvis and femur. Therefore those muscles don't require a post-surgical healing process, and the patient's recovery time is significantly reduced.
are allowed to immediately bear weight fully on their replaced hip
on the day of surgery. Although all patients are different with regard
to their pre-operative health status it is not unusual to see patients walking
one to two miles a day by their three week post-op check.
Watch Dr. Woods' talk at French Hospital: Total Hip Replacement Using the Anterior Muscle Sparing Approach
Dr. Woods has written a 4-page handout that explains in detail the new technique: Total Hip Replacement Using the Anterior Muscle Sparing Approach.