Hip Revision is an operation to reconstruct (i.e. to re-do) a previous Total Hip Replacment that has developed functional problems. A revision hip replacement may be necessary for a number of different complications that may occur with a hip replacement. A hip replacement may wear out!Older model replacements had plastic (High density polyethylene) bearings in the socket, and this polyetheylene wears out over the years. The small wear particles of polyetheylene cause tissue irritation and a local inflammation resulting in bone damage, and "loosening" of the components, often with bone destruction and absorption. Similar problems can occur with break up of cement used to fix components. Revision may also be needed for infection in the joint, or if the hip is unstable and dislocates regularly and easily.

 Hip revisions are much more complex surgeries than primary (or first time) hip replacements because of the removal of the primary implant, previous scarring, loss of bone, and/or possible infection. The difficulty with surgery due to the altered anatomy, and uncertain operative findings, means the operation is more difficult, and may take a much longer time, with a greater risk of complications occurring, and greater blood loss.  Revision hip replacement may require a post operative period in the Intensive Care Unit, and results in a longer hospital stay, and slower and more protracted rehabilitation. Patients requiring Revision Hip replacement are older than those having their first operation(!), and so have more medical conditions to be cared for also, contributing to the overall increae in difficulty with this group of patients. Fortunately, Primary Total Hip Replacement is such a successful operation for most people, that the percentage of patients requiring revision surgery remains quite low.

If possible, the surgeon will attempt to use the same surgical incision site used in the primary surgery. Once the implant is exposed, the surgeon will separate the thighbone component from the socket (acetabular component.) This is called dislocating the implant.

Click here to view an animation - Dislocated Implant.
 

Once the implant is dislocated, the surgeon will begin the removal process. For the thighbone (femoral component) the surgeon will use special tools to remove any bone cement and/or loosen the implant from the existing bone. The surgeon must be careful not to fracture the existing bone and must leave as much bone as possible since it will help strengthen the revision implant.

Click here to view an animation - Bone Cement Removed During Surgery.
 

Extensive bone loss may require the use of a bone graft. The bone graft may be harvested from your pelvic bones during the revision procedure, or obtained from a bone bank.

With the removal of the implant, a hollow canal is exposed in the center of the bone. The canal is cleaned by removing the remaining cement, diseased tissue or bony debris to facilitate the re-insertion of the new implant.

Click here to view an animation - Canal Cleaning.
 

Next the socket or acetabular component is removed. If the component was held in place with screws, these are removed, along with any cement that may have been applied to hold the cup in place. Once the component is removed, cement and/or bone particles will be removed from the cavity. The surgeon may then make changes to the acetabular cavity such as enlarging it and/or repairing any fractured bone to allow for the insertion of the new acetabular component.

Click here to view an animation - Acetabular Component Removed.
 

Once the component is removed, the revision surgery will continue much like the primary hip implant surgical procedure.