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Advantages of Hip Resurfacing

The advantage of hip resurfacing over traditional total hip replacements is an area of controversy among orthopaedic surgeons. Research is currently being done on this topic.

• Hip resurfacings may be easier to revise (redo). 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 15 to 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, and it is closer to the size of the natural ball of your hip. Because of this, it may be harder to dislocate. This stance is controversial because several factors can affect the risk of dislocation, including the 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, the friction between the two surfaces can lead to the release of tiny metal molecules called ions. The ions can cause a reaction in the bone and soft tissues surrounding the joint called an adverse local tissue reaction. This can cause pain and swelling and may lead to the need for revision surgery. The ions may also enter the bloodstream and have systemic (body-wide) effects. For this reason, hip resurfacing is now performed less frequently than in the past.
  
  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.
  
  

Before Surgery

You will likely be admitted to the hospital on the day of surgery.

Before your procedure, a doctor from the anesthesia department (anesthesiologist) will evaluate you. They 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)
• Regional (you are awake, but your body is numb from the waist down)

Your surgeon will also see you before surgery and sign your hip with a marker to verify the surgical site.

Surgical Procedure

A hip resurfacing operation typically lasts from 1-1/2 to 3 hours. During the procedure, your surgeon will:

• Make an incision in your thigh to reach the hip joint.
• Dislocate the femoral head out of the socket. 
• Trim the head with specially designed power instruments.
• Cement a metal cap over the prepared femoral head.
• Use a power tool called a reamer to remove the cartilage that lines the socket.
• Push a metal cup into the socket; the cup is held in place by friction between the bone and the metal.
• Once the cup is in place, position the femoral head back into the socket, and close the incision.

After 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 be taken to your hospital room.