What is the difference between cemented and cementless total hip replacement?
Cemented total hip replacement uses cement to secure an implant to the bone, while with cementless technology the bone heals directly to the prosthesis. The results of cemented and cementless total hip replacement are essentially identical. Theoretically, cementless hip replacements should have a longer lifetime and are desirable in patients who have good enough bone quality to accommodate a cementless implant.
Who should get a cemented hip replacement vs. a cementless hip replacement?
The answer can be realized by examining several ways in which an artificial hip can fail. These include implant fracture, wear and loosening. Although metal can break, the new super-alloy metals have minimized this problem. Plastic wear is another problem, but advances in design and materials have reduced this as well. Implant loosening continues to be a concern, however. The weak link for most active patients is the cement bond between the implant and bone. By adding a porous, rough surface to the implant and eliminating the use of bone cement, bone in growth into the implant can occur, providing a living bond between the implant and bone. It is theorized that, over time, the constant stress of daily activities would actually strengthen the bone-implant link rather than weaken it.
Experience has shown that young, active or heavy patients are most likely to loosen a cemented total hip replacement. For these patients, the cementless total hip replacement appears to be the most durable design. Patients with poor bone quality or with less active lifestyles are candidates for cemented total hip replacement.
What are the bearing surfaces available?
Bearing surfaces are the layers which take up the friction which occurs due to the movement of the joint. The surfaces available are Highly Crosslinked Polyethylene on Metal, Highly Crosslinked Polyethylene on Ceramic, Highly Crosslinked Polyethylene on Oxynium & Ceramic on Creamic.
Will my new hip dislocate?
Total hip replacement dislocation is a painful condition in which the prosthetic femoral head, or the “ball” on the proximal end of the femur or thigh bone, no longer articulates, or “comes out of joint,” with the socket in the acetabular cup of the pelvis.
Initial management and reduction (relocating the ball of the hip joint back into the socket of the acetabular component of the pelvis) of dislocation require an emergency room visit.
Reduction requires the use of anesthesia with its inherent health risks, whether reduction takes place in the emergency room or in the operating room. Reoperation may become necessary if closed methods of reduction are not successful.
How often does hip dislocation it happen after total hip replacement?
The incidence of dislocation can vary and is as high as 4%. The incidence at the Apollo Hospitals, Bangalore is less than 0.5%. Dislocation is the second most common reason for revision surgery after prosthetic loosening. Multiple revision surgeries can increase the rate of dislocation to 25%. Timing from surgery: Up to one third of dislocations occur within 6 weeks after surgery (early dislocations), and the rest happen after 6 weeks (late dislocations).
Why does dislocation happen after total hip replacement?
There are many reasons why a total hip dislocation can occur:
Surgical Approach: The posterolateral approach has the highest associated incidence of dislocation, and this is believed to be due to straightening of the spine and flexing of the pelvis in the side-lying position used during this approach on the operating table. This may lead to an inappropriately positioned socket. Use of this approach following a hip fracture is also associated with an increased risk of dislocation. The rate of dislocation with this approach and others decreases inversely with the experience of the surgeon.
Orientation of the components: Proper component orientation is the most important factor in preventing future dislocations. The prosthetic stem position depends upon the surgical approach, but in general it should be anteverted, or angulated forward, by about 10 degrees. Proper socket positioning requires more experience and most authors have reported component stability in 30 45 degrees of abduction (lateral angulation) and 10 degrees of anteversion (forward angulation). A malpositioned component may be protected from dislocation after the early post-operative period due to soft-tissue and capsular healing. Long-term dislocation rates (late dislocations occurring 5 to 10 years after surgery) of 0.4% suggest soft tissues cannot indefinitely compensate for component malposition. Such long-term dislocations may also be due to component wear over time.
Prosthetic component design: Dislocation can result from problems with component design and/or selection. If the components are not properly selected, the prosthetic femoral neck may lever against bony prominences around the pelvis. This “impingement” must be avoided as the prosthesis can lever out of the acetabulum in certain positions: extension/external rotation and flexion/internal rotation.
Inadequate restoration of soft tissue tension/failure of the abductor mechanism: Restoring the appropriate degree of soft tissue tension (tightness) is one of the most important factors in preventing dislocation following a total hip replacement. 75% of patients with dislocation have poor soft tissue tension due to a variety of reasons. Previous hip surgery and/or revision arthroplasty surgery may predispose to problems with soft tissue tension and have been associated with increased incidences of dislocation. Detachment of the insertion of the abductor muscles into the greater trochanter of the femur or trochanteric nonunion following an approach using a trochanteric osteotomy leads to inadequate soft tissue tension and is one of the major causes of dislocation.
Patient cooperation: A patient’s noncompliance with total hip precautions (proper body positioning) increases the likelihood that a dislocation will occur.
How can you prevent dislocation?
Proper body positioning is the key factor in preventing dislocation. In the early post-operative period, learning total hip precautions, or positions of potential instability to avoid, are critical. As surgical incisional pain decreases beyond the immediate post-operative period, it is important for the patient to remember the presence of the prosthetic joint and not to become too careless about their activities.
Can dislocation be treated without surgery?
Fortunately, most dislocations can be treated without surgery. Options include bracing, casting, or watchful waiting following a period of bedrest. These methods of treatment are most appropriate for dislocations occuring within the first six weeks to three months following the initial surgery. Such early dislocations are generally believed to be due to relaxed soft tissues and immature scar tissue. Immobilization of the hip allows time for sufficient scar tissue solidation so that recurrent dislocations and reoperation are less likely.
In the absence of component malposition or soft tissue imbalance, patient re-education and use of a hip brace or cast can be successful if worn continuously for six weeks. Abduction bracing and spica casting have been successful in preventing recurrent dislocation in up to 95% of cases studied.
When is surgery necessary after dislocation?
The rule of “three strikes and you’re out” applies: most surgeons recommend revision arthroplasty following the third dislocation. Systematic evaluation can guide surgical correction to the specific problem or problems causing the total hip replacement to dislocate recurrently.
Radiographic evaluation with a combination of plain x-ray views of the pelvis and affected hip can be used to assess the orientation of the patient’s components, to evaluate the trochanteric mechanism if an osteotomy was used, and to evaluate for polyethylene liner wear. Component angulation too far laterally (excessive abduction) or too far posteriorly (excessive retroversion), trochanteric nonunion, and acetabular wear are all problems which may contribute to instability and are amenable to operative correction.
CT scanning can also be used to assess the orientation of the prosthetic components if this not evident from plain radiographs.
If gross component malposition is discovered during the radiographic work-up, studies have shown that operative intervention should be undertaken sooner rather than later. Such malpositioned components generally fail conservative treatment.
Studies have shown that surgical management is most successful in preventing further dislocations when a specific component problem, soft tissue problem, or both are found and therefore corrected with revision surgery.
What can be done about dislocation?
Change the orientation of malpositioned components: Removal of malaligned components and placement of new components in the proper orientation as described above should by definition prevent further dislocations since stability is inherent in a properly positioned prosthetic joint.
“Tighten up the soft tissues” through trochanteric advancement: Trochanteric advancement involves removing the greater trochanter from the femur along with its attached abductor muscles and reattaching them distally down the femur to “tighten up” the muscles on the lateral side of the leg and to reposition the trochanter so that it is less likely to impinge upon the pelvis. This procedure has a variable success rate in management of chronic dislocation with soft tissue laxity with no other identifiable causes.
Removal of impinging cement, bone spurs, or soft tissues: In one series impingement was believed to be the primary cause of instability in 10% of patients; however, its surgical correction led to only a 50% success rate in preventing further dislocations. Impingement is more often an important secondary cause of instability, and removal of its sources is an important step at the time of revision surgery for other primary causes.
Use a constrained acetabular socket: Constrained acetabular sockets are a new alternative to traditional components and are indicated in patients who continue to dislocate despite appropriate revision surgery or in whom no correctable cause of instability can be found. They are designed to decrease the likelihood of dislocation by preventing the extremes of hip motion which can lead to instability. Various models of constrained sockets have been used successfully in such patients up to 96% of patients having no subsequent dislocations.
How Painful is Hip Replacement Surgery?
No surgery is painless, and hip replacement surgery is no exception. However, postoperative pain from hip replacement surgery is very manageable. Despite their surgical pain, it is not unusual for patients to relate how much relief they quickly notice from their preoperative arthritic pain. While the experience of pain is unique to each individual, most patients manage the immediate postoperative pain from hip replacement without difficulty.
How will my pain be managed?
Most patients getting hip replacement surgery undergo spinal anesthesia. This type of anesthesia has many benefits, not the least of which is the continuation of pain relief for several hours after surgery. Additionally, spinal anesthesia has been demonstrated in studies to have other benefits such as decreased surgical blood loss and a decreased risk of the development of lower extremity blood clots when compared with general anesthesia. While spinal anesthesia can provide the main anesthesia for hip replacement, patients are still sedated so that they are not aware of the surgery as it is occurring. The muscle relaxation provided by spinal anesthesia also makes performing the surgery easier and therefore less traumatic for the patient.
After surgery, patients are treated with other pain medicine, either by mouth or intravenously. While it may seem surprising, often the postoperative pain from hip replacement can be managed with just oral pain medicine. This spares the patient from the side effects of often stronger intravenous medicine. If it is felt that intravenous medicine is needed, patients are usually provided with a form of patient-controlled analgesia (PCA). The administration of this type of pain relief is controlled by the patient. The patient presses a button which releases a set amount of pain medicine intravenously. This allows the patient to get pain medicine on a timely basis without, for example, waiting for a nurse to administer the medication. Patients generally do not have to worry about taking too much medicine, because there is a set limit of medicine that can be delivered this way. These types of pain control are generally provided until the day after surgery. After this, most pain medicine is provided in pill form as needed.
How long will I have pain after surgery?
It is difficult to give a specific answer for this, but most patients notice good pain relief within the first week after surgery. Surgical pain is usually at its worst for the first 24 to 48 hours after surgery. After this, patients are usually more comfortable. They may experience some increased pain when doing exercises or therapy, but this can be easily managed by timing the administration of pain medicine to coincide with therapy.
What can I do to help manage my pain?
The most important thing that patients can do is to let their treatment team know about the pain they are experiencing. This is usually expressed on a scale of 1 (little or no pain) to 10 (severe pain). This information helps the healthcare team to provide the right type and amount of pain medication. Patients can also help relieve their pain with means other than pain medicine. For example, applying ice and elevation to the hip area after therapy can go a long way toward controlling the swelling that often causes discomfort after such activity. On the other hand, when patients have discomfort from stiffness, usually doing some exercises will help relieve this pain more than any medicine will.
Is it OK to take pain medicine?
Some patients almost have a fear of taking pain medicine. Some patients think that they will quickly become addicted to narcotic medication. This is simply not true. Postoperatively, patients have a good reason to have pain and this is appropriately treated with pain medicine. It often takes less narcotic to control a person’s pain when the medicine is taken appropriately – that is, when the patient begins to experience real discomfort. In the early postoperative period, patients should not try to “hold off” on taking pain medicine because they think the pain will calm down in time. These patients who “hold off” until their pain becomes too severe often eventually need more narcotic to control their pain than they otherwise would have needed if they had taken their pain medicine earlier.
What are the side effects of pain medicine?
Side effects of pain medicine and anesthesia include nausea, constipation, and sometimes a tired feeling. Having these side effects does not mean that a patient is allergic to the medication. If a patient has a problem with these side effects, often the medication can be adjusted or a different medication tried in order to minimize these effects.
When is my first post operative consultation?
1st post-op visit is 4-6 weeks from date of surgery if you have staples 1st post-op visit is 2 weeks from date of surgery if you have sutures.
When will my staples or sutures be removed?
At approximately two weeks from your surgical date. They will be removed and Steri-Strips are applied and will eventually wash off. Staples will be removed at the rehab center or at home and if you have sutures they will be removed in the office.
How long will I remain on anticoagulation (blood thinners)?
This is prescribed for up to 6 weeks post-operatively. Your medical clearance doctor will arrange a home health nurse to take blood 1-2 times a week to appropriately dose your Coumadin. This is not necessary if you have been placed on aspirin only.
Is swelling of my knee, leg, foot, and ankle normal?
Yes, for three to six months. To decrease swelling, elevate your leg and apply ice for 20 minutes at a time (3-4 times a day).
Is it normal to feel numbness around the hip?
Yes, it is normal to feel numbness around the incision.
What exercise should I perform at home?
Please do exercises as instructed by your surgeon. Please refer to the hip replacement booklet that was provided to you. Remember that if you are using your hip to do things, you are actually doing physical therapy for your hip.
How long will I need to use a cane?
This varies with each patient. Usually between 2-6 weeks.
Do I have to observe hip precautions?
Our general policy is that hip precautions are not required. You should avoid things that are uncomfortable, but you are allowed to sit on regular chairs, use regular toilet seats, go in a car, and lay or sleep on your side. You do not need to use high chairs, elevated toilet seats or pillows between your legs, but they may be more comfortable for you in the initial period after surgery. There may be exceptions to this that will be explained to you specifically by your surgeon.
May I go outdoors prior to my first postoperative visit?
Yes, we encourage you to do so.
May I drive or ride in a car before my first postoperative visit?
Yes, you may ride in a car, however, you must be off all pain medications prior to driving. It is a patient’s responsibility to determine their own safety. If your right hip is replaced, you should wait for a month before driving.
May I ride in an airplane before my first postoperative visit?
Yes, you may ride in an airplane. Be sure to get up and move around at frequent intervals. You may find it more comfortable in an aisle seat.
Why is my leg bruised?
It is common to have bruising on the skin. It is from the normal accumulation of blood after your surgery.