Fig. 11.2 Anteroposterior radiograph demonstrating a mid-diaphyseal aggre ssive, lytic, destructive lesion of the femur with periosteal reaction, cortical thinning, and associated soft-tissue mass (arrows) concerning for impending pathologic fracture. (Radiograph courtesy of Drew D. Moore, MD).
IV. Behaviors of Tumor Subtypes
A. A review of pathologic fractures would be remiss without discussion of tumor subtype behavior. Not all metastatic lesions behave the same and many vary in their response to adjuvant treatments such as radiation and chemotherapy.
B. These “personalities” directly affect oncologic approach, and not respecting these differences can impact construct survivorship, lead to pitfalls in management, and compromise quality of life.
C. Prostate metastases tend to be blastic and the role for prophylactic fixation is low in these cases.
D. Renal and thyroid metastases are notorious for their hypervascularity—liberal use of tourniquet control, when applicable, and strong consideration for preoperative embolization can significantly limit blood loss and assist with local hemostasis during procedures for these hypervascular lesions (▶Fig. 11.3).
E. Plasma cell neoplasms (plasmacytoma and multiple myeloma) and lymphoma respond favorably to adjuvants such as radiation and chemotherapy.
F. Large extraosseous soft-tissue masses can impart significant alteration in normal anatomy. These tumor burdens will significantly decrease with radiation and chemotherapy, and there is little role for aggressively excising these masses unless arthroplasty is being performed for pathologic fracture.
G. Renal cell carcinoma and melanoma are classically less responsive to radiation therefore alternative strategies including the use of surgical adjuvants is helpful to decrease tumor burden and risk of local disease progression (▶Table 11.3).
H. Neoplasms of mesenchymal lineage are termed sarcomas and their behavior, approach, and treatment greatly differs from that of carcinoma, myeloma, or lymphoma.
I. The extent of bone and soft-tissue sarcoma management is beyond the scope of this chapter, but a basic understanding of their presentation and management is instrumental to avoid complications when treating pathologic fractures.
1. Any biopsy performed in the suspicion of a bone sarcoma should be carried out at an institution that is best suited for definitive management.
Fig. 11.3 Angiogram demonstrating a hypervascular proximal humerus renal metastases that was successfully embolized prior surgery.
Table 11.3 Surgical adjuvants
| Mechanical | Chemical | Thermal |
| Curettage | Phenol | Argon beam coagulation |
| Burr | Sterile/distilled water | Electrocautery |
| Hydrogen peroxide (H2O2) | Liquid nitrogen (cryotherapy) | |
| Polymethylmethacrylate |
2. The biopsy tract should be in line with a future limb salvage approach and meticulous hemostasis should be used to avoid contamination. If clinical suspicion is high for a primary musculoskeletal malignancy, the biopsy should typically be referred to a musculoskeletal oncologist to perform.
3. Neurovascular structures and intermuscular planes should be avoided.
V. Treatment and Management
The principle goal is balancing quality of life and function with disease management. There is little role for restricted weight-bearing or prolonged recovery in the treatment of metastatic disease as median survivorship is often less than 12 months depending on tumor subtype. A sound understanding of disease stage, performance status, patient goals, tumor subtype, and anatomic location are paramount in successful management of these challenging situations.
A. Humerus
1. Location in the bone often guides treatment options, as lesions proximally involving the humeral head or distally about the elbow are likely best managed with prosthetic replacement.
2. Reverse total shoulder and alloprosthetic composite have gained favor in their ability to provide pain relief and return to function while balancing complications (▶Fig. 11.4).
3. Diaphyseal lesions are largely treated with intramedullary fixation or, in rare situations, an intercalary resection and reconstruction (renal cell).
4. Metaphyseal lesions can be approached with internal fixation in the form of plates/screws or an intramedullary nail depending on location and extent of disease. Surgical adjuvants (▶Table 11.3) play an important role in decreasing local tumor burden, limiting progression of disease, and increasing construct stability which can lead to longer implant survivorship.
B. Acetabulum
1. The acetabulum is one of the most challenging anatomic locations in the treatment of bone neoplasms given critical locoregional anatomy and associated surgical morbidity.
2. Complications such as instability, infection, and construct failure have to be weighed against tumor subtype, disease burden, and life expectancy.
3. Nonoperative adjuvants such as radiation or bisphosphonate treatments or minimally invasive options such as interventional cryoablation, radiofrequency ablation, or cementoplasty play important roles in the options available to manage impending fractures.
4. Completed fractures that involve the weight-bearing dome that are associated with debilitating pain and functional limitation are best approached with complex arthroplasty. Use of bone cement and Steinmann pins, porous metal augments, or large acetabular shells combined with antiprotrusio cages can be used to reconstruct large osseous defects.
5. Tumor subtype and extent of disease will often dictate surgical timing as the treatment of periacetabular myeloma and lymphoma will largely be initiated with radiation, bisphosphonates, and chemotherapy followed by delayed surgical reconstruction (▶Fig. 11.5).
C. Femur
1. Pathologic fractures of the femoral head and neck are best served with arthroplasty.
a. Various lengths of stem options (curved and straight) and proximal bodies should be available (calcar replacing, modular).
Fig. 11.4 Lateral radiograph of a humerus demonstrating a long stem cemented modular reverse proximal humerus replacement for reconstruction after en bloc resection of a solitary proximal humerus renal cell pathologic fracture.
Fig. 11.5 Anteroposterior pelvis radiograph demonstrating multiple screws, cement, and a trabecular metal revision acetabular shell used