Patients with advanced arthritis of the hip may be candidates for either traditional total hip replacement or hip resurfacing. Each of these procedures is a type of hip replacement, but there are important differences. Your orthopaedic surgeon will talk with you about the different procedures and which operation would be best for you.
The hip is a ball-and-socket joint. In a healthy hip, the bones are covered with smooth cartilage that enables the femoral head and acetabulum to glide painlessly against each other.
In a traditional total hip replacement, the head of the thighbone (femoral head) and the damaged socket (acetabulum) are both removed and replaced with metal, plastic, or ceramic components. In hip resurfacing, the femoral head is trimmed and capped with a smooth metal covering. The damaged bone and cartilage within the socket is removed and replaced with a metal shell, just as in a traditional total hip replacement.
(Left) In the x-ray of a hip resurfacing taken from the front, a metal cap now covers the femoral head, and a small stem is seen in the femoral neck. A metal socket is also in place. Unlike the traditional total hip replacement shown on the right, the femoral head and neck are not removed.
Advantages of Hip Resurfacing
The advantages of hip resurfacing over traditional total hip replacements is an area of controversy among orthopaedic surgeons. A great deal of research is currently being done on this topic.
- Hip resurfacings may be easier to revise. Because the components (called implants) used in hip replacements and hip resurfacings are mechanical parts, they can — and do — wear out or loosen over time. This typically occurs between 10 and 20 years after the procedure, although implants may last longer or shorter periods of time.
- If an implant fails, an additional operation may be necessary. This second procedure is called a revision and it can be more complicated than the initial operation. Because hip resurfacing removes less bone from the femur (thighbone) than a traditional hip replacement, many surgeons believe it is easier to exchange implants that fail after hip resurfacing.
- Decreased risk of hip dislocation. In hip resurfacing, the size of the ball is larger than in a traditional hip replacement. Because of this, it may be harder to dislocate. This stance is controversial because several factors can affect the risk of dislocation, such as surgical approach, and the type and size of the implants used.
- More normal walking pattern. Some studies have shown that walking patterns are more natural following hip resurfacing compared to traditional hip replacement. These differences in walking are quite subtle, however, and special instruments are needed to measure them.
Disadvantages of Hip Resurfacing
- Femoral neck fracture. A small percentage of hip resurfacing patients will eventually break (fracture) the thighbone at the femoral neck. If this occurs, it is usually necessary to convert the hip resurfacing into a traditional hip replacement.
- A femoral neck fracture is not possible with a traditional hip replacement because the femoral neck is removed during this procedure. However, fractures around the implants can still occur with a traditional hip replacement.
- Metal ion risk. In hip resurfacing, a metal ball moves within a metal socket. Over time, this leads to the production of tiny metal particles called ions. Some patients may develop sensitivity or allergy to the metal particles, which may cause pain and swelling. Also, there are concerns that the metal particles may increase the risk of cancer, although this has never been proven. Some types of traditional hip replacements also consist of a metal ball and a metal socket and these replacements run the same potential risks. Ask your doctor for more information about metal-on-metal implants.
- Hip resurfacing is a more difficult operation. Hip resurfacings are more difficult than total hip replacements for surgeons to perform. As such, a larger incision is usually required for a hip resurfacing compared to a total hip replacement.
Candidates for Surgery
Your doctor may recommend surgery if you have more advanced osteoarthritis and have exhausted the nonsurgical treatment options. Surgery should only be considered if your hip is significantly affecting the quality of your life and interfering with your normal activities.
Unlike hip replacement, hip resurfacing is not suitable for all patients. Generally speaking, the best candidates for hip resurfacing are younger (less than 50), larger-framed patients (often, but not always male) with strong, healthy bone. Patients that are older, female, smaller-framed, with weaker or damaged bone are at higher risk of complications, such as femoral neck fracture and should be treated with total hip replacement.
Before your procedure, a doctor from the anesthesia department will evaluate you. He or she will review your medical history and discuss anesthesia choices with you. You should also have discussed anesthesia choices with your surgeon during your preoperative clinic visits. Anesthesia can be either general (you are put to sleep) or spinal (you are awake but your body is numb from the waist down).
Your surgeon will also see you before surgery and sign your hip to verify the surgical site.
A hip resurfacing operation typically lasts between 1-2 hours.
Your surgeon will make an incision in your thigh in order to reach the hip joint. The femoral head is then dislocated out of the socket. Next, the head is trimmed with specially designed power instruments. A metal cap is cemented over the prepared femoral head. The cartilage that lines the socket is removed with a power tool called a reamer. A metal cup is then pushed into the socket and held in place by friction between the bone and the metal. Once the cup is in place, the femoral head is relocated back into the socket and the incision is closed. After the surgery you will be taken to the recovery room, where you will be closely monitored by nurses as you recover from the anesthesia. You will then either be discharged home or admitted to the hospital. Patients admitted to the hospital are usually discharged after a one night stay.
As with any surgical procedure, there are risks involved with hip resurfacing. Your surgeon will discuss each of the risks with you and will take specific measures to help avoid potential complications.
Although rare, the most common complications of hip resurfacing are:
- Blood clots. Blood clots in the leg veins are the most common complication of hip resurfacing surgery. Blood clots can form in the deep veins of the legs or pelvis after surgery. Blood thinners such as warfarin (Coumadin), low-molecular-weight heparin, aspirin, or other drugs can help prevent this problem.
- Infection. You will be given antibiotics before and after your surgery to prevent infection.
- vessels may be injured or stretched during the procedure.Injury to nerves or vessels. Although it rarely happens, nerves or blood.
- Femoral neck fracture
- Risks of anesthesia
You may begin putting weight on your leg immediately after surgery, depending on your doctor’s preferences and the strength of your bone. You may need a walker, cane, or crutches for the first few weeks until you become comfortable enough to walk without assistance.
You can expect some pain and discomfort during the recovery period. Many types of pain medication are available to help control pain, including opioids, nonsteroidal anti-inflammatory drugs (NSAIDs) and local anesthetics. Treating pain with medications can help you feel more comfortable, which will help your body heal faster and recover from surgery faster.
Opioids can provide excellent pain relief, however, they are a narcotic and can be addictive. It is important to use opioids only as directed by your doctor. You should stop taking these medications as soon as your pain starts to improve. You will be given exercises to help maintain your range of motion and restore your strength.
Hip replacement has become necessary for your arthritic hip: this is one of the most effective operations known and should give you many years of freedom from pain.
Once you have arthritis that has not responded to conservative treatment, you may well be a candidate for a resurfacing procedure of the hip.
A standard hip replacement replaces the acetabulum (hip socket) and the places a femoral component inside the femur (thigh bone). Hip Resurfacing or bone conserving procedure replaces the acetabulum (hip socket) in the same way but resurfaces the femoral head. This means the femoral head has some or very little bone removed that is replaced with the metal component. This spares the femoral canal.
Resurfacing procedures may be indicated in the young patient (usually less than 55 years) who has osteoarthritis and wishes to maintain an active lifestyle. It is a more conservative and less traumatic alternative to Total Hip Replacement (THR).
Arthritis is a general term covering numerous conditions where the joint surface (cartilage) wears out. The joint surface is covered by a smooth articular surface that allows pain free movement in the joint. This surface can wear out for a number of reasons, often the definite cause is not known.
When the articular cartilage wears out, the bone ends rub on one another and cause pain. There are numerous conditions that can cause arthritis and often the exact cause is never known. In general, but not always, it affects people as they get older. This form of arthritis is referred to as Osteoarthritis.
Other causes include
- Childhood disorders e.g., dislocated hip, Perthe’s disease, slipped epiphysis etc
- Growth abnormalities of the hip (such as a shallow socket) may lead to premature arthritis
- Trauma (fracture)
- Increased stress e.g., overuse, overweight, etc.
- Avascular necrosis (loss of blood supply)
- Connective tissue disorders
- Inactive lifestyle- e.g., Obesity, as additional weight puts extra force through your joints which can lead to arthritis over a period of time
- Inflammation e.g., Rheumatoid arthritis
In an Arthritic Hip
- The cartilage lining is thinner than normal or completely absent. The degree of cartilage damage and inflammation varies with the type and stage of arthritis
- The capsule of the arthritic hip is swollen
- The joint space is narrowed and irregular in outline; this can be seen in an X-ray image
- Bone spurs or excessive bone can also build up around the edges of the joint
- The combinations of these factors make the arthritic hip stiff and limit activities due to pain or fatigue
The diagnosis of osteoarthritis is made on history, physical examination & X-rays. There is no blood test to diagnose Osteoarthritis (wear & tear arthritis).
Indications & Advantages
Resurfacing procedures may be indicated in the young patient (Less than 55 years) who has osteoarthritis and wishes to maintain an active lifestyle. It is a more conservative and less traumatic alternative to Total Hip Replacement (THR).
The main advantage is that it is bone sparing in that it does not violate the femoral canal. This allows a Total Hip Replacement to be performed at a later date, if required, with little difficulty.
- Higher activity levels allowed
- Quicker recovery in hospital (2 to 5 days)
- Reduced bone damage and Osteolysis (erosion of bone) over time
- Reduced complications, especially reduced dislocation rate and reduced leg discrepancy
Conventional Hip Replacement
- Suitable for older patients
- Femoral canal violation
- Metal on polyethylene, metal on metal or ceramic on ceramic articulation
- Can wear out rapidly
- Risk of dislocation
- Leg length discrepancy
- Osteolysis (bone wearing out)
- Thigh pain
- May require revision surgery
- Requires restriction of activities
- Suitable for younger patients
- Femoral canal left intact
- Metal on metal articulation
- Longer lasting, with better wear characteristics
- Less risk of dislocation
- Minimal or no leg discrepancy
- Less risk of osteolysis
- No thigh pain
- Revision surgery less likely
- Able to be more active
Your surgeon will send you for routine blood tests and any other investigations required prior to your surgery.
You will be asked to undertake a general medical check-up with a physician.
You should have any other medical, surgical or dental problems attended to prior to your surgery.
Make arrangements for help around the house prior to surgery.
Cease aspirin or anti-inflammatory medications 10 days prior to surgery as they can cause bleeding.
Cease any naturopathic or herbal medications 10 days before surgery.
Stop smoking as long as possible prior to surgery.
Day of Surgery
- You will be admitted to hospital usually on the day of your surgery
- Further tests may be required on admission
- You will meet the nurses and answer some questions for the hospital records
- You will meet your Anesthetist, who will ask you a few questions
- You will be given hospital clothes to change into and have a shower prior to surgery
- The operation site will be shaved and cleaned
- Approximately 30 minutes prior to surgery, you will be transferred to the operating room
An incision is made over the hip to expose the hip joint.
The acetabulum (socket) is prepared using a special instrument called a reamer.
The acetabular component is then inserted into the socket. This is sometimes reinforced with screws or occasionally cemented.
A liner which can be made of plastic, metal or ceramic material is then placed inside the acetabular component
The femur (thigh bone) is then prepared. The femoral head which is arthritic is cut off and the bone prepared using special instruments, to exactly fit the new metal femoral component.
The femoral component is then inserted into the femur. This may be press fit relying on bone to grow into it or cemented depending on a number of factors such as bone quality and surgeon’s preference.
A trial reduction (putting the hip back into place) is performed to make sure everything fits well.
The real femoral head component is then placed on the femoral stem. This can be made of metal or ceramic.
- The hip is then reduced again, for the last time
- The muscles and soft tissues are then closed carefully
You will wake up in the recovery room with a number of monitors to record your vitals, (Blood pressure, Pulse, Oxygen saturation, temperature, etc.) You will have a dressing on your hip and drains coming out of your wound.
Post-operative X-rays will be performed in recovery.
Once you are stable and awake you will be taken back to the ward.
You will have one or two IV’s in your arm for fluid and pain relief. This will be explained to you by your anesthetist.
On the day following surgery, your drains will usually be removed and you will be allowed to sit out of bed or walk depending on your surgeon’s preference.
Pain is normal but if you are in a lot of pain, inform your nurse.
You will be able to put all your weight on your hip and your physical therapist will help you with the post-op hip exercises.
You will be discharged home or to a rehabilitation hospital approximately 5-7 days depending on your pain and help at home.
Sutures are usually dissolvable but if not are removed at about 10 days.
A post-operative visit will be arranged prior to your discharge.
You will be instructed to with crutches for two weeks following surgery and to use a cane from then on until 6 weeks post-op.
Remember this is an artificial hip and must be treated with care.
Avoid the Combined Movement of Bending Your Hip and Turning Your Foot In. This can cause Dislocation. Other precautions to avoid dislocation are:
- You should sleep with a pillow between your legs for 6 weeks. Avoid crossing your legs and bending your hip past a right angle
- Avoid low chairs
- Avoid bending over to pick things up. Grabbers are helpful as are shoe horns or slip on shoes
- Elevated toilet seats are helpful
- You can shower once the wound has healed
- You can apply Vitamin E or moisturizing cream into the wound once the wound has healed
- If you have increasing redness or swelling in the wound or temperatures over 100.5 degrees you should call your doctor
- If you are having any procedures such as dental work or any other surgery you should take antibiotics before and after to prevent infection in your new prosthesis. Consult your surgeon for details
- Your hip replacement may go off in a metal detector at the airport
Risks and Complications
As with any major surgery, there are potential risks involved. The decision to proceed with the surgery is made because the advantages of surgery outweigh the potential disadvantages.
It is important that you are informed of these risks before the surgery takes place.
Complications can be medical (general) or specific to the Hip
Medical complications include those of the anesthetic and your general well being. Almost any medical condition can occur so this list is not complete. Complications include
- Allergic reactions to medications
- Blood loss requiring transfusion with its low risk of disease transmission Heart attacks, strokes, kidney failure, pneumonia, bladder infections
- Complications from nerve blocks such as infection or nerve damage
- Serious medical problems can lead to ongoing health concerns, prolonged hospitalization, or rarely death
Infection can occur with any operation. In the hip this can be superficial or deep. Infection rates are approximately 1%. If infection occurs it can be treated with antibiotics but may require further surgery. Very rarely your hip may need to be removed to eradicate infection.
Blood Clots (Deep Venous Thrombosis)
These can form in the calf muscles and can travel to the lung (Pulmonary embolism). These can occasionally be serious and even life threatening. If you get calf pain or shortness of breath at any stage, you should notify your surgeon.
This means the hip comes out of its socket. Precautions need to be taken with your new hip forever. If a dislocation occurs it needs to be put back into place with an anesthetic. Rarely this becomes a recurrent problem needing further surgery.
Fractures (break) of the femur (thigh bone) or pelvis (hipbone)
This is also rare but can occur during or after surgery. This may prolong your recovery, or require further surgery.
Damage to Nerves or Blood Vessels
Also rare but can lead to weakness and loss of sensation in part of the leg. Damage to blood vessels may require further surgery if bleeding is ongoing.
Your scar can be sensitive or have a surrounding area of numbness. This normally decreases over time and does not lead to any problems with your new joint.
Leg length inequality
It is very difficult to make the leg exactly the same length as the other one. Occasionally the leg is deliberately lengthened to make the hip stable during surgery. There are some occasions when it is simply not possible to match the leg lengths. All leg length inequalities can be treated by a simple shoe raise on the shorter side.
Leg length inequalities are less likely to occur with a resurfacing procedure.
All joints eventually wear out. The more active you are, the quicker this will occur. In general 80-90% of hip replacements survive 15- 20 years.
Resurfacing procedures should last longer, but this has to be proven by long term studies and with the latest designs.
Failure to relieve pain
Very rare but may occur especially if some pain is coming from other areas such as the spine.
Unsightly or thickened scar
Pressure or bedsores
Limp due to muscle weakness
Discuss your concerns thoroughly with your Orthopaedic Surgeon prior to surgery.
Surgery is not a pleasant prospect for anyone, but for some people with arthritis, it could mean the difference between leading a normal life or putting up with a debilitating condition. Surgery can be regarded as part of your treatment plan—it may help to restore function to your damaged joints as well as relieve pain.