Revision Hip Replacement Surgery
A revision hip replacement involves removing the previous prosthesis and replacing it with a new one.
In the absence of a complication, most hip replacements should last 20 years and potentially much longer. However, occasionally hip revision surgery is needed to remove and replace a worn, loosened or misaligned implant to relieve pain, improve function or prevent dislocation.
Reasons for revision surgery:
Implant loosening, wear or infection.
Occasionally trauma can occur to the hip, such as in a serious road accident or fall. This could result in a fracture of the upper end of the femur that may disrupt the stability of the hip and require surgery.
Component fractures occur very rarely. Fracture of the femoral stem is usually due to loosening and loss of support from the surrounding bone.
A similar situation can occur in the case of plastic acetabular components which are not loaded correctly, often due to misalignment at the original operation. One of the rarest types of fractures is that of ceramic articulating components and is usually the result of trauma or improper assembly.
Symptoms/signs your hip replacement may be in trouble:
Recurrence of pain particularly when you start walking (‘’start-up pain’’).
Limp, stiffness or weakness.
Instability and dislocation.
Recovery and outcomes from revision surgery:
The surgery is usually more complex and time consuming than the original operation, particularly where there is infection, a lack of adequate bone stock, or difficulty separating the implants from the bone.
The surgery can take longer to perform with specialized techniques and equipment being required. The extensive nature of revision surgery can affect recovery as the surgical trauma, scar tissue, and mechanical weakening of bone can reduce performance of the hip joint and muscles.
If the revision is due to an infection, the surgeon will have to perform the operation in two stages. The first stage involves taking out the previous components and inserting some bone cement with antibiotics into the joint. The second stage is carried out after 10-12 weeks if there is no more infection. Your surgeon will then remove the bone cement and place the new joint implants.
Care after hip revision surgery is similar to the care after total hip replacement, including physical therapy and pain medications as needed. Blood thinning medication will also be given to reduce the risk of blood clots. Usually you will be ‘’fully weightbearing’’ but occasionally a period of ‘’non- weightbearing’’ or ‘’partial- weightbearing’’ is necessary to protect the early healing. A Zimmer frame or crutches will be used early in your recovery period, then you will progress to a walking stick and eventually the vast majority will be walking without any assistance.
As this is complex surgery, occasionally complete pain relief and restoration of full function is not always possible. However, strength and mobility continue to improve over one to two years after hip revision surgery.
More than 90% of patients who undergo revision procedures can expect good to excellent results. It is important to ‘get it right’ during revision surgery to prevent the need for later remedial surgery. Mr Ashworth’s NJR results show he is in the top 25% for avoiding the need for any further surgery after a revision operation.
Complications of revision hip replacement surgery:
Generally, the risk involved with revision surgery are similar in nature to that of first-time hip replacement, but with higher magnitude.
The risks of revision hip replacement include (but are not limited to):
Infection – rare but potentially catastrophic. The infection rate in revision hip replacement surgery is reported to be around 2-4% (Mr Ashworth’s infection rate is lower than this). Infection may need further operations to wash out or revise the implants. In the case of infection, a staged procedure (two stage operation) is preferred by Mr Ashworth due to its higher success rate than a one stage operation. This involves a first operation to remove the existing implants and cement, and clean the hip thoroughly. An antibiotic spacer is then inserted to keep the joint under tension, to deliver antibiotics to the local area and permit hip movement to prevent stiffness. Intravenous antibiotics are then commenced for 6 weeks, and then ceased if the blood tests indicate the infection has cleared. The revision hip replacement is then inserted in a second operation usually 12 weeks after the first.
Dislocation or instability – the hip replacement may slip part way out of the joint (sublux). This usually settles as the deep tissues heal after surgery. Occasionally dislocation of the ball out of the socket occurs. This requires a general anaesthetic or very heavy sedation to reposition the ball in the socket. Usually the hip then stabilises but on rare occasions with repeated instability/dislocation remedial surgery is needed.
Loosening – the bond between the metal implant and the bone can fail, leading to loosening due to bone loss (osteolysis) this can be painful. This requires repeat revision surgery.
Pain – Occasionally patients are left with pain after otherwise successful surgery. Further investigation can often identify this and treatment is successful in the majority of cases. However, the investigations may take many months to identify the cause.
Wound irritation or numbness - Occasionally, there is some dull aching around the scar for many months, which can become worse in cold weather, but this is usually nowhere near as uncomfortable as the pain you had before the operation. The operation incision will always cut some skin nerves, so you may have numbness around the wound. This does not affect the function of your joint but may be irritating to you over the short to medium term. Eventually, this numb feeling improves and does not worry most people. Very occasionally, instead of a numb sensation you may have burning or a hypersensitive sensation. This usually settles down over many months but on very rare occasions it can be permanent and troublesome.
Wear – the polyethylene in the socket can wear with time, requiring surgery. Sometimes a new polyethylene can be inserted, but usually the wear is associated with loosening of the component. In this situation, the hip replacement will have to be re-revised.
DVT/PE – Deep Vein Thrombosis (DVT) involves formation of blood clot in the deep calf veins. This may occur after surgery, trauma, or even spontaneously. Hip replacement revision is associated with a higher risk of DVT. Special precautions are taken, including pneumatic calf pumps and blood thinning injections followed by tablets. Despite these measures, DVT can occasionally occur. DVT causes calf pain and swelling, but its most concerning consequence is when the clot breaks free and travels to the lungs (called Pulmonary Embolism or PE), causing shortness of breath or chest pain. Very occasionally this can be serious or even life-threatening.
Injury to nearby nerves– rare, but may be associated with impaired long term function (e.g., a foot drop weakness with numbness – usually recovers within 6-9 months but a splint is used to prevent tripping up).
Injury to nearby blood vessels – exceptionally rare and requires emergency surgery to resolve. This has never happened to a case Mr Ashworth has operated on.
Bleeding – blood transfusion is occasionally required following revision hip replacement surgery.
Stiffness – persistent stiffness following revision surgery may occur very rarely due to pain restricting movement.
Fracture – a rare complication. If this occurs, further surgery or a period of non-weightbearing may be required.
Heterotopic ossification - This is bone forming in the soft tissues surrounding the hip. This can cause discomfort for up to 18 months and occasionally needs to be excised if it restricts movement.
Implant breakage - This is exceedingly rare and usually due to osteolysis causing loss of support to the implant. If this were to occur, reoperation to remove the broken implant and replace it with a new one would be required.
Anaesthetic problems (these will be discussed by your anaesthetist when you meet them)– Anaesthetic agents have been associated with allergic and anaphylactic reactions. In addition, the medications can depress the function of the heart and lungs. In older or more prone patients this may lead to heart attack, stroke, or cardiac failure.