What is a revision hip replacement?
Revision hip replacement surgery is a procedure in which an existing prosthesis is revised or replaced with a new total hip implant. An original total hip implant has two broad components, one on femoral side and other on acetabular side. Each of these components also has further subcomponents, for example an uncemented cup has an outer shell and inner polyethylene (plastic) liner, while femoral component has stem and modular head.
Thus a revision total hip replacement can be a revision of all the components or revision of one component, for example only change of polyethylene (plastic) liner.
Revision Hip Replacement
Revision total hip replacement surgery is a demanding surgery, but the results are good in the vast majority of patients, though not as good as primary total hip replacement surgery.
When is it needed?
The Primary total hip replacement is a very successful operation with high survival rate for 10-15 yrs. The problem, unfortunately, is that slowly and progressively, hip replacements wear out over a period of time. 15 years after a hip replacement, there is a 90 - 95% chance that the implant will be functioning well. 20 years after surgery, the chance is about 80% and it keeps reducing progressively over the years. A loose hip implant tends to be painful and unstable, therefore patients who wear out their prosthesis will require a revision hip replacement surgery
Hip replacements can wear out for a variety of reasons. By far the most common cause of wear is Aseptic Loosening.
Other causes for revision hip surgery are Infection, repeated Dislocations, Osteolysis (development of loose bone cavities around hip implant without loosening of implant), Periprosthetic Fractures (breaking of the bone around the prosthesis), Implant Fracture (breaking of the prosthesis) etc.
Depending on the cause of the implant failure, sometime treatment other than direct revision hip replacement may be necessary. For example, in the case of infection, the hip implant may need to be removed to treat the infection, an antibiotic spacer need to be inserted along with few weeks of antibiotics, and once infection is controlled then revision hip replacement is performed.Other causes for revision hip surgery are Infection, repeated Dislocations, Osteolysis (development of loose bone cavities around hip implant without loosening of implant), Periprosthetic Fractures (breaking of the bone around the prosthesis), Implant Fracture (breaking of the prosthesis) etc.
Depending on the cause of the implant failure, sometime treatment other than direct revision hip replacement may be necessary. For example, in the case of infection, the hip implant may need to be removed to treat the infection, an antibiotic spacer need to be inserted along with few weeks of antibiotics, and once infection is controlled then revision hip replacement is performed.
How different is revision hip surgery different than primary total hip replacement?
The principles of revision THA are similar to those of primary hip replacement surgery. However, revision hip surgery is more challenging and complicated than primary hip replacement. Poor quality of the patients bone often makes it difficult to achieve stable fixation of revision hip implants. Furthermore, removing the previous knee implants not only necessitates more extensive surgery, but also adds to loss of bone to the already limited patient bone stock (remaining bone).
Also not only do the patients tend to be older, but also the surgery time is longer and the blood loss is greater during or after surgery adding to the difficulty of revision surgery. Together, these problems make revision hip replacement much more complex surgery.
Revision hip surgery on an infected hip requires two or more separate operations. In the first operation, the old hip prosthesis is taken out and a block of cement mixed with high dose of antibiotics (antibiotic spacer block) is inserted in the joint for 6 - 12 weeks. This block acts as a spacer and also releases high concentration of antibiotics in the hip joint locally. The patient is also given intravenous antibiotics for 6 weeks, and constantly evaluated with repeated TLC, DLC, CRP and ESR. After the infection has cleared, the hip is reopened and the new revision prosthesis can be implanted.
During the revision surgery one may need special implant like longer and wider stems, cages, rings, bone graft, mesh, etc. Though these implants are expensive and have some limitations, but indispensable (in certain situation) to achieve good stability of revision implant.
How revision total hip replacement can help me?
The revision total hip replacement surgery is a successful and durable operation, though not as much as primary total hip replacement surgery. You can expect significant improvement in your symptoms after revision hip surgery, which includes:
- Significant relief in pain
- Restoration of movements
- Stable joint
How do I know when I need revision hip replacement?
If your pain is increasing, if you are having difficulty in walking or you have to use a support for walking, if you are having instability on getting up, if you having repeated hip joint dislocations, or there is continuous discharge from the operative scar not responding to any treatment, then its time for you to consult your doctor for the possibility of revision total hip replacement.
Sometimes you may have few or no symptoms, but the x-rays show a big osteolysis next to the implant necessitating a revision hip replacement. Some other time you may be very symptomatic, and x-rays also show gross malalignment or loosening of components or change in the position of components or you has sustained periprosthetic fracture, you will be better off with revision hip surgery.
The decision and extent of revision hip replacement depends on cause of revision hip surgery, severity of discomfort, x-rays, blood investigations like CRP, TLC, DLC or ESR and your overall clinical condition. At times you will be requiring to undergo special investigations like Tc99 Bone scan / I111 bone scan or MRI scan to confirm the diagnosis and assess true extent of lesion. It is essential to remove a loose or damaged prosthesis before irreversible harm is done to the joint and surrounding bone.
Underlining the complex nature of surgery, the right time for revision hip replacement can be decided by you together with your Orthopedic surgeon in consultation with Physician and Anesthetist.
If you have a hip replacement and think you may need revision surgery, you must discuss your options with your orthopedic surgeon.
What should I expect during my hospital stay?
Before Surgery: Most of the patients are admitted two days before surgery and undergo a through medical checkup which includes evaluation by the treating surgeon, anesthetist, intensivist, and physiotherapist besides investigations like Chest X-rays, ECG, blood (including CRP, ESR, TLC & DLC) and urine test. X-ray images of pelvis with hip and thighbone from different angles are taken to plan your surgery. You may require whole body bone scan or CT / MRI of the hip joint to assess the bone loss around implant. At least 2 – 3 units of blood may be necessary. Careful control of blood sugar is done in Diabetic patient before surgery.
Hip joint is scrubbed with soap and water, painted with betadine solution, and then covered with a sterile drape in your room a night before your operation.
Surgery: Preferable choice of anesthesia is Spinal anesthesia (it anesthetize both legs only) with sedation. The duration of surgery ranges from 2 to 3 hrs. You will be kept in a recovery room for one day for the monitoring of vital parameters. You will be requiring abduction pillow (a pillow between the legs to keep them wide apart). Knee / static quadriceps and hip abductor exercises are started on the day of surgery.
After Surgery: On the 3rd day your drainage tubes will be removed while on 4th day your dressing will be changed. In most cases a knee immobilizer will be worn. Knee bending on the CPM machine is started 2-3 days after surgery; bedside sitting is started on the 4th day while walking with support and toilet training are started from 5th day onwards.
Most patients can ambulate comfortably with the support of a stick or walker, bend knee up to 800 to 900, start going to toilet and are also able to climb a flight of stairs. Most patients are comfortably discharged on 7th to 8th day.
What happens after I go home?
Aftercare following hip revision surgery is essentially the same as for primary hip replacement, consisting of a combination of physical therapy, rehabilitation exercises, pain medication when necessary, and a period of home health care or assistance.
You will be requiring antibiotics for a longer time as compare to primary total hip replacement surgery especially if you are a diabetic, rheumatoid arthritis patient or infection was the cause of revision hip surgery.
The recovery time after revision hip replacement surgery depends on the cause of revision and may vary from 4 to 8 weeks.
What are the risk following Revision Total Hip Replacement?
The complications following revision hip surgery are similar to those for primary hip replacement surgery and include:
- Deep vein thrombosis
- Infection in the new prosthesis: Incidence of reinfection following revision total hip replacement are higher in comparison to primary total hip replacement especially in diabetic and rheumatoid arthritis patient or if revision surgery has been done for infection of primary hip.
- Loosening of the new prosthesis. The risk of this complication is increased considerably if the patient is overweight.
- Bone fractures during the operation. These are caused by the force or pressure that the surgeon must sometimes apply to remove the old prosthesis and the cement that may be attached to it.
- Dislocation of the new prosthesis. The risk of dislocation is thrice as great for revision surgery as for THR.
- Formation of heterotopic bone. Heterotopic bone is bone that develops at the lower end of the femur following hip replacement or hip revision surgery. Patients who have had an infection in the joint are an increased risk of heterotopic bone formation.