Factors to Consider When Choosing a Surgical Approach for Total Hip Arthroplasty (THA) Revision

1. Existing Surgical Scars:

Surgeons performing THA revisions typically have a preferred or familiar surgical approach. However, THA revisions are often complex, with various factors influencing the choice of approach.

If possible, it is advisable to use the original incision. By sliding the skin and superficial fascia, especially when extending the incision, adequate deep exposure can be achieved in all directions. If there are multiple old surgical scars on the affected limb, the incision should follow the most recent scar. In cases where an initial or revision THA must be re-operated within days or weeks, using the previous approach minimizes tissue damage and provides easier access. However, the previous incision or approach should not be the sole determinant; if it does not provide adequate exposure of the hip joint, it should not be used for the revision (Figure 1 A-B).

Figure:

1. A: An old surgical scar extending posteriorly to the right buttock.

2. B: In the revision surgery, a direct lateral approach was chosen, with the distal incision along the old scar and the proximal incision directed anteriorly.

2. Patient Anatomy:

Hip disorders can lead to abnormal hip joint anatomy. For instance, patients with congenital hip dysplasia may require acetabular implants to be placed in pseudoacetabulum positions. When revising such implants, extensive exposure of the superior acetabulum is needed, which can be safely achieved using a posterolateral or transtrochanteric approach. However, using an anterolateral or transgluteal approach to expose the superior acetabulum may risk injury to the superior gluteal nerve. Anatomical abnormalities from previous surgeries, such as femoral varus deformity, may necessitate corrective osteotomy during THA revision to accommodate a longer femoral revision stem. Heterotopic ossification can hinder surgical manipulation, especially posteriorly, leading to hip stiffness. In such cases, a transtrochanteric or extended trochanteric osteotomy (ETO) should be considered. Patients with intertrochanteric osteolysis should avoid a transtrochanteric osteotomy.

3. Removal or Retention of Existing Implants:

Generally, any surgical approach provides good exposure around the acetabulum unless there are reconstruction rings or cage supports at the acetabular roof or ischial ramus (Figure 2). Additionally, when plates and screws are used for fixation in acetabular posterior column fractures or pelvic discontinuity, their removal may be necessary during THA revision due to interference with implant insertion. Posterior or extensile approaches facilitate easier removal of implants and safer acetabular implant placement (Figure 3 A-B). If retaining the acetabular implant, its orientation influences the choice of surgical approach. For example, a posterior approach should be avoided if the retained acetabular implant is retroverted. Medially displaced acetabular implants can typically be safely removed extrapelvically via a standard approach (Figure 4 A-B). If the implant is firmly adherent to intrapelvic tissues, a retroperitoneal approach may be required.

Figure:

2. Good exposure around the acetabulum through a direct lateral approach.

Figure:

3. A: Plates and screws fixed in the acetabulum due to a fracture, with screws penetrating the joint surface.

   B: Screws removed via the posterior approach and a biological acetabular cup implanted.

Figure:

4. A: X-ray of a 72-year-old male showing medial displacement of the left acetabular implant.

   B: Original acetabular implant safely removed extrapelvically via a direct lateral approach, and a larger biological acetabular implant inserted.

The method of fixation of the femoral prosthesis components is crucial, particularly with well-fixed cement mantles or biological femoral stems, as this influences the surgical approach. Extensile approaches, especially ETO, facilitate quicker removal of well-fixed implants, prevent accidental fractures, and maintain the muscle attachment to the trochanteric osteotomy fragment, aiding in healing and functional recovery (Figure 5 A-G).

Figure:

5. A-G: Illustrations showing various aspects of femoral prosthesis component management, including cemented femoral stems and the use of extensile approaches.

4. Bone Defects:

Surgeons frequently encounter varying degrees of bone defects during THA revisions. Severe bone defects require extensive exposure, and the location of these defects is a key factor in choosing the surgical approach. For instance, significant superior posterior acetabular defects requiring bulk allograft or metal block augmentation are more easily addressed via posterior or extensile approaches (Figure 6). For pelvic discontinuity requiring posterior column plating, the posterior or extensile approach is also crucial. In contrast, femoral bone defects less commonly dictate the choice of surgical approach.

Figure:

6. Posterior approach using a metal block to fill a severe superior posterior acetabular defect.

5. Hip Stability and Surgeon's Training and Experience:

It is widely recognized that dislocation rates following THA revision are higher than after primary THA. Studies show that anterior, anterolateral, and transgluteal approaches have lower dislocation rates than posterior approaches. Surgeons may avoid posterior approaches for patients at high risk of dislocation, such as those with neuromuscular imbalances, poor compliance, or posterior soft tissue deficiencies. Transtrochanteric and extended trochanteric osteotomies may be followed by trochanteric advancement to improve hip stability and abduction function in cases of soft tissue insufficiency.

Proficiency in the chosen surgical approach is vital for surgeons performing THA revisions. The approach should allow adequate exposure, minimize surgical time, reduce blood loss, and reliably restore joint function. However, each surgical approach has limitations, so surgeons should be adept in multiple approaches to address intraoperative challenges effectively.