Abstract
The surgical approach that is adequate for a primary total hip replacement may need to be modified to achieve a more extensile exposure as required for the revision procedure. A straightforward revision total hip replacement procedure can become quite complex when implant removal is attempted without adequate skill, instrumentation, or exposure. The most commonly used approaches in total hip replacement revision surgery are the transtrochanteric, posterolateral, and anterolateral. Although the effects of these approaches on the long-term clinical survival of the prosthetic composite are not completely clear, surgical approach does affect dislocation rates, trochanteric nonunion rates, and other indicators of clinical success.
Transtrochanteric Approach - Three variations of the transtrochanteric approach exist: A) The classic Charnley trochanteric approach was popularised by virtue of its use in primary total hip arthroplasty (THA) and, therefore, was easily applied to revision THA. This approach allows excellent visualization of the lateral shaft of the femur, thus enhancing implant and cement removal. However, the classic Charnley approach is associated with a high incidence of trochanteric nonunion. Reattachment of the atrophied trochanteric fragment often requires adjunct fixation such as cables, hooks, or bolts. These devices can subsequently break, migrate, or generate particulate debris which, in turn, is capable of producing extensive granuloma. B) The trochanteric slide is accomplished by an anteromedial inclination of the osteotomy, thus providing a more stable interface for reattachment. The trochanteric slide offers the advantage of maintaining muscle continuity. The disadvantage of this technique is decreased visualization of the acetabulum. Adjunct fixation of the trochanter is also required with this approach. C) By creating a 6 cm to 12 cm distal extension to the trochanteric fragment, a large lateral window is developed which enhances both prosthesis and cement removal. Subsequently, trochanteric fixation is enhanced because the extended fragment increases the surface area available for fixation. Because the extended trochanteric osteotomy requires a larger bone resection, proximal femoral bone stock can be compromised. As a result, proximal prosthetic support with a tapered device can force the trochanteric fragment laterally, increasing the likelihood of nonunion. When an extended trochanteric osteotomy is used, the patient's postoperative physical therapy and rehabilitation course should be modified to protect the healing trochanteric fragment.
Posterolateral Surgical Approach is used commonly in revision THA. The technique is popular because it is used widely for endoprosthetic replacement in the treatment of subcapital fractures. Also, the posterolateral approach is quite popular for primary THA. This approach has the advantage of maintaining the integrity of the abductor mechanism. Although femoral exposure is adequate, acetabular exposure can be limited. Also, this approach is associated with an increased incidence of dislocation. Another concern is its close proximity to the sciatic nerve, thus predisposing the patient to the risk of nerve injury.
Anterolateral Surgical Approach has the advantage of improved visualization of the acetabulum and femur without the attending trochanteric complications and proximity to the sciatic nerve. This approach is associated with a low incidence of dislocation. However, the abductor muscle is divided or split and, therefore, abductor dysfunction can occur post-operatively. There also can be an increased incidence of heterotopic ossification, but it avoids the problem of trochanteric nonunion.
