What is Revision Total Hip Replacement?

A hip replacement surgery is a standard procedure that many people undergo. It involves a prosthesis referred to as a ball and socket that must be assembled both before and during the operation. It mimics the function of the human hip joint throughout the life of the prosthesis. However, the prosthesis is prone to different types of mechanical and biological defects. If the defect occurs post-surgery, then another operation known as a revision total hip replacement might be necessary to deal with the defects.

When to consider a revision hip replacement?

In older patients who undergo a total hip replacement, the prosthesis has a life of around 15-20 years which can last them for a lifetime depending on their age. However, if the first hip replacement surgery is done at a young age and the patient is physically active, they might need one or more revisions of hip replacement surgery.

Preoperative exams of those who need a revision hip replacement are more meticulous than those who undergo it for the first time. For revision surgery, X-Ray projections, CT Scans, or MRI might be required to locate the prosthesis position, parts that need replacement, and bone loss around the failed implant. If the surgeon has a suspicion of infection around the old prosthesis, they might suggest some blood tests as well.

Reasons

The revision hip replacement surgeries are not performed frequently. Following are the reasons for revision hip replacement surgery-

  • Frequent dislocation of the implant
  • Mechanical defects like wear and tear of the prosthesis
  • Infection

Previously we mentioned that the hip replacement prosthesis resembles a natural human hip like a ball and socket. The prosthesis will work efficiently only when the ball is inside the socket. Following are the two key things that keep the ball inside the socket-

  • The alignment and fitting of both the ball and socket
  • The force created by stronger muscles and ligaments surrounding the hip joint

The range of motion of the hip prosthesis is large, but some hip positions can pop the ball out of the socket. The condition is known as a dislocated hip.
A patient who carefully sticks to the surgeon’s precautions and instructions rarely has any dislocations. However, the pre-existing conditions in some patients might make them likely to suffer a hip dislocation. They include older debilitated patients and those who get a hip replacement after suffering from a hip fracture or have had various hip surgeries.

Once a patient suffers a hip dislocation, they are prone to other dislocations because the ruptured ball disturbs the other important surrounding muscles and ligaments.

New dislocations are avoided after revision surgery. Before a revision surgery, the surgeon might require imaging tests to see the location and position of the previously replaced parts. There might be a need to re-position more than one part or, at times, completely exchange them.

If possible, the surgeon will use a constrained socket that can capture the ball inside the socket. For the surgery to be successful, the soft tissues around the hip replacement need to heal fully. Thus, wearing braces for a few weeks after the surgery is suggested. Post-surgery it is vital to follow the surgeon’s instruction to the T and avoid moving the hip into positions that might cause a dislocation.