Many patients who are candidates for total hip surgery have had a previous surgical procedure on their hips.
Having surgery on your hip in the past does not pre-vent you from having a total hip in the future. In fact, many patients have surgery for one problem which leads to arthritis later in life. For example, patients who have had hip disease during childhood or adolescence may function well and have a pain-free hip for many years. They may progress to arthritis as they become older.
Prior surgery may impose special set of circumstances on total hip replacement. The anatomy may be different and there may be scar formation in many areas. The surgeon will try to identify as much of the normal anatomy as possible. He will also try to identify and protect vital structures such as the sciatic nerve, which may be encased in scar and difficult to identify.
Some of the conditions that are often treated surgically prior to total hip replacement are:
1. Developmental Dysplasia of the Hip
Many infants or children with developmental dysplasia of the hip are treated with closed reduction and splinting or bracing. Sometimes an open reduction may be necessary. The anatomy of the hip may not be completely normal as it grows. The acetabulum may be more vertical and may have less bone. The femur may be smaller and narrower. The angle of the neck of the femur or anteversion may be different than a normal hip. The leg may be shorter than normal.
2. Slipped Capital Femoral Epiphysis
Slipped capital femoral epiphysis occurs during the early to mid teenage years. It is often treated by insertion of pins or screws. Sometimes it is necessary to cut the bone to reshape the hip. This is called an osteotomy. The osteotomy is held in place with a plate and screws.
If total hip arthroplasty is performed in later years, the fixation hardware may need to be removed. Beyond this, the femoral head and neck may be rounded or deformed. The head may be rotated posteriorly or retroverted. All of this will need to be considered if hip replacement is done.
3. Perthes Disease
Perthes disease is a disease of childhood that occurs between ages 3 and 7 years. Most often treatment is closed and consists of casting or bracing. In teenage years, however, an osteotomy may be performed. As with slipped epiphysis, there may be residual hard-ware and ongoing deformity of the femoral head and neck.
4. Reconstructive Osteotomy
An osteotomy can also be done as treatment for osteoarthritis in a younger patient. Hardware and scar formation will be a consideration.
5. Hip Fusion
Forty or fifty years ago, hip fusion was done as treatment for osteoarthritis in a younger patient. It was also sometimes done as treatment for an infection of the hip bone or hip joint. In a hip fusion, the cartilage of the femur and the acetabulum has been removed and the bones have been allowed to grow together or fuse.
While hip fusion was frequently successful in relieving pain in younger patients, it completely eliminated any mobility of the hip joint.
Some patients would now like to have the benefits of total hip replacement even though they have had a fusion in the past. The operation is especially difficult because a large amount of bone must be cut, or osteotomized, and removed. Some of the contracted soft tissues around the old joint must be divided. The basic anatomy of the joint must be identified and reestablished.
A “take down” of an old hip fusion can be a difficult procedure, but it is frequently rewarding. Your goals and expectations will play a large role in a decision to have this type of surgery.
6. Post-Traumatic Arthritis
Total hip replacement after fixation for a fracture is common.
A fracture of the femur or acetabulum that has been treated surgically can often lead to post-traumatic arthritis years down the line. Removal of hardware in this situation may make for a bigger operation. If, for example, a rod has been placed in the femur, multiple incisions may have to be made in order to remove all the components of the rod. By the same token if there has been a surgical repair of the acetabulum, it may be necessary to repeat the acetabular exposure in order to remove all of the hardware that has been placed around the rim of the socket. If the socket has been damaged by the fracture, there may be less bone for placement of the new acetabular component.
7. Avascular Necrosis
Avascular necrosis of the femoral head may be treated primarily with hip replacement, but some-times a previous surgical procedure has been attempted to prevent collapse of the femoral head. Placement of a cortical bone graft or nail in the neck of the femur will have to be considered when the procedure is planned. The bone graft in the femoral neck may make it more difficult to ream the femoral canal and place a femoral stem.
8. Infection
If you have had previous surgery for an infection in your hip, care has to be taken to make sure that bac-teria do not remain within the bone or within the joint. A low grade infection can be present in bone for many years without being obvious clinically. Your surgeon may want to check for any signs of residual infection before he considers total hip replacement. He will want to take blood tests and may want to do an imaging study such as a bone scan or indium scan. He may even want to with-draw fluid from the joint and send it to the laboratory for culture to make sure there are no bacteria. During surgery, he may take additional culture specimens and may ask the laboratory to analyze some of the tissue while surgery is still in progress. Prior infection can make total hip replacement more technically difficult and care should be taken to make sure that none of the infection remains. In almost all cases, the surgeon is likely to find a large amount of scar tissue if there has been previous surgery.
Your orthopaedic surgeon can discuss any of these conditions with you. He can tell you how your previ-ous hip surgery may affect your upcoming procedure.