Total Hip Replacement

Total Hip Replacement

 

Anatomy

Other conditions that can cause destruction of the hip joint include loss of the blood supply to the head of the thighbone (osteonecrosis), rheumatoid arthritis, injury, infection, and developmental abnormalities of the hip. Patients with arthritis may also have brittle bones (osteoporosis), but there is no direct relationship between bone density and the development of arthritis of the hip.

Osteoarthritis of the hip is the most common reason for a hip replacement. Osteoarthritis is caused by the wear and tear of aging. It causes the cartilage covering the joint surfaces to wear out, resulting in pain and stiffness. Minimally invasive hip replacement allows the surgeon to perform the hip replacement through one or two small incisions. Patients usually have less pain compared with traditional hip replacement surgery, and rehabilitation is faster. Total hip replacement is a common orthopaedic procedure. As the population ages, it is expected to become even more common. Hip replacement surgery involves removing the head of the thighbone (femur) and replacing the ball-and-socket mechanism of the hip with artificial implants. This relieves pain and improves mobility.

Types of Hip Replacement

Early studies suggest that minimally invasive hip replacement surgery streamlines the recovery process, but the risks and long-term benefits of less-invasive techniques have not yet been documented.

Traditional Hip Replacement

Traditional hip replacement surgery involves making a 10- to 12-inch incision on the side of the hip. The muscles are split or detached from the hip, allowing the hip to be dislocated.  Once the joint has been opened up and the joint surfaces exposed, the surgeon removes the ball at the top of the thighbone, or femur. The hip socket is prepared by removing any remaining cartilage and some of the surrounding bone. A cup-shaped implant is then pressed into the bone of the hip socket. It may be secured with screws. A smooth plastic bearing surface is then inserted into the implant so the joint can move freely.  Next, the femur is prepared. A metal stem is placed into the femur to a depth of about 6 inches. The stem implant is either fixed with bone cement or is implanted without cement. Cementless implants have a rough, porous surface. It allows bone to adhere to the implant to hold it in place. A metallic ball is then placed on the top of the stem. The ball-and-socket joint is recreated.

 

Minimally Invasive Hip Replacement

Minimally invasive hip replacement surgery allows the surgeon to perform the hip replacement through one or two smaller incisions. Candidates for minimal incision procedures are typically thinner, younger, healthier, and more motivated to have a quick recovery compared with patients who undergo the traditional surgery. Before you decide to have a minimally invasive hip replacement, get a thorough evaluation from your surgeon. Discuss with him or her, the risks and benefits. Both traditional and minimally invasive hip replacement procedures are technically demanding. They require that the surgeon and operating team have considerable experience.

Technique

The artificial implants used for the minimally invasive hip replacement procedures are the same as those used for tradictional hip replacement. Specially designed instruments are needed to prepare the socket and femur and to place the implants properly.  The surgical procedure is similar, but there is less soft-tissue dissection. A single minimally invasive hip incision may measure only 3 to 6 inches. It depends on the size of the patient and the difficulty of the procedure. The incision is usually placed over the outside of the hip. The muscles and tendons are split or detached, but to a lesser extent than in the traditional hip replacement operation. They are routinely repaired after the surgeon places the implants. This encourages healing and helps prevent dislocation of the hip. Two-incision hip replacement involves making a 2- to 3-inch incision over the groin for placement of the socket. A 1- to 2-inch incision is made over the buttock for placement of the stem. To perform the two-incision procedure, the surgeon may need guidance from X-rays. It may take longer to perform this surgery than it does to perform traditional hip replacement surgery.

Benefits

Reported benefits of less invasive hip replacement include:

  • Less pain
  • More cosmetic incisions
  • Less muscle damage
  • Rehabilitation is faster
  • Hospital stays are shorter

For traditional hip replacement, hospital stays average 4 to 5 days. Many patients need extensive rehabilitation afterward. With less-invasive procedures, the hospital stay may be as short as 1 or 2 days. Some patients can go home the day of surgery.