Total Hip Arthroplasty for Oncologic Conditions

Stephen M. Petis

Matthew P. Abdel

Key Concepts

The majority of pelvic girdle and femoral bone tumors are bony metastases. Primary bone tumors may occur in the pelvic girdle in up to 15% of cases.
Bone tumors can create large segmental bone deficits, which makes stable implant fixation to host, nonpathologic bone challenging.
Preoperatively, patients should be medically optimized to address anemia and other anomalies such as hypercalcemia. Cases should be staged locally and systemically and evaluated and treated in corroboration with a multidisciplinary oncology team.
Radiographs and cross-sectional imaging should be carefully assessed to map out planned resections and predict residual bone defects that require reconstructions.
Oftentimes, bone loss is much greater than anticipated, and pathologic pelvic discontinuities frequently are present.
These cases necessitate a wide armamentarium of implants to manage bone defects—cemented and cementless implants, allograft-prosthetic composites, tantalum acetabular components and augments, supplemental cages, megaprostheses, and structural allografts.
Surgical approach and exposure are dictated by the location of the tumor. An approach should be selected that allows complete resection of the tumor if primary in nature or adequate visualization of bone defects for stable reconstruction if metastatic.
There will be 2 main focuses of this chapter:
- Acetabular reconstructions for periacetabular lesions, with emphasis on 2 groups:
  - Primary periacetabular lesions: Wide excision and acetabular reconstruction are needed
  - Metastatic periacetabular lesions: Only acetabular reconstruction is needed
- Femoral reconstructions for femoral lesions, with emphasis on 2 groups:
  - Primary femoral lesions: Wide excision and femoral reconstruction are needed
  - Metastatic femoral lesions: Only femoral reconstruction is needed
For primary periacetabular lesions, there are 4 types of resections and reconstructions:
Type I: Resection at sciatic notch (Figure 20.1)
Type II: Supra-acetabular resection (Figure 20.2)
Type III: Posterior column preserved (Figure 20.3)
Type IV: Anterior column preserved (Figure 20.4)

Sterile Instruments and Implants

Instruments

Routine hip retractors
Saws (reciprocating and oscillating) for bone resection

Wide range of sizes of acetabular reamers to accommodate various bone defect sizes and morphologies

Figure 20.1 ▪ Illustration depicting a Mayo type I resection at the level of the sciatic notch, mandating the most difficult acetabular reconstruction on the ilium. (Used with permission of Mayo Foundation for Medical Education and Research. All rights reserved.)

Figure 20.2 ▪ Illustration depicting a Mayo type II supra-acetabular resection mandating a large acetabular reconstruction on the ilium. (Used with permission of Mayo Foundation for Medical Education and Research. All rights reserved.)

Figure 20.3 ▪ Illustration depicting a Mayo type III resection where the posterior column is preserved and utilized for the acetabular reconstruction. (Used with permission of Mayo Foundation for Medical Education and Research. All rights reserved.)

Figure 20.4 ▪ Illustration depicting a Mayo type IV resection where the anterior column is preserved and utilized for the acetabular reconstruction. (Used with permission of Mayo Foundation for Medical Education and Research. All rights reserved.)

Metal-cutting burr
6.5-mm burr
Flexible reamers to bypass complex defects during femoral preparation
Intraoperative imaging
3.5-mm drill bit

Acetabular Implants

Allograft bone
Highly porous metal acetabular component
Highly porous metal augments
Supplemental acetabular cages for cup-cage constructs
Cementless or cemented femoral components
Megaprostheses
Occasionally, a custom acetabular component will be required (see Section II-D, Chapter 6).

Femoral Implants

Cemented stems of various lengths are needed depending on the location of the metastatic disease.
Modular, fluted tapered stems of various lengths and diameters can be utilized for primary lesions requiring proximal resection.
Megaprostheses with either cemented or uncemented distal fixation can be considered for primary lesions requiring proximal resection.

Positioning

Lateral decubitus position

Surgical Approaches

A posterolateral or anterolateral approach may be appropriate for most periacetabular lesions requiring acetabular reconstruction, as well as most femoral reconstructions.
More complex surgical approaches, such as an extended iliofemoral approach, may be required for more extensive bone resections and acetabular reconstructions.

Preoperative Planning