Pathological Fracture after Radiation and Surgical Resection of Soft Tissue Sarcomas

1. Pathological Fracture after Radiation and Surgical Resection of Soft Tissue Sarcomas Authors: Nahhas, Mohammed, and Isler, Marc

2. Pathological Fracture after Radiation and Resection of Soft Tissue Sarcoma Introduction • the combination of high dose radiation and resection of soft tissue sarcomas in the long bones predisposes to pathological fracture, particularly when associated with periosteal stripping • some authors suggest prophylactic fixation • is this justified?

3. Pathological Fracture after Radiation and Resection of Soft Tissue Sarcoma Risk factors • Periosteal stripping • Radiation • Chemotherapy • Female • Anterior compartment resection

4. Pathological Fracture after Radiation and Resection of Soft Tissue Sarcoma • Scarborough,CORR,389,2001 • periosteal stripping increases the rate of fracture by removing the intramembranous reparative mechanism (the periosteum) and disruption of the vascular supply to the bone.

5. Pathological Fracture after Radiation and Resection of Soft Tissue Sarcoma Materials and methods • Retrospective review of a prospective database • known risk factors • incidence of fracture, type of trauma • success of fracture treatment

6. Pathological Fracture after Radiation and Resection of Soft Tissue Sarcoma Inclusion criteria • Soft tissue sarcoma of thigh and leg • limb-sparing surgical resection & >50gy RT • age 18 and older • Fracture site in field of radiation

7. Pathological Fracture after Radiation and Resection of Soft Tissue Sarcoma Exclusion criteria • Superficial sarcoma ( completely above deep fascia) or upper limb sarcomas • Bone lesions, or soft tissue sarcomas requiring osseous resection • benign soft tissue tumors

8. Pathological Fracture after Radiation and Resection of Soft Tissue Sarcoma Results • 1990 to 2003 • 245 lower extremity sarcomas of soft tissue were resected • before (or after) radiation therapy

9. Pathological Fracture after Radiation and Resection of Soft Tissue Sarcoma Results • 9 fractures in 245 patients (4%) • 5 Females/ 4 Males • No prior infections • mean latency of 29.6 months • only minimal trauma (e.g. fall from standing height)

12. Pathological Fracture after Radiation and Resection of Soft Tissue Sarcoma Results of fracture treatment • intramedullary nailing • 2 cases (22%) developed nonunion • no infections

13. Pathological Fracture after Radiation and Resection of Soft Tissue Sarcoma Discussion • reported incidence of 6% to 25% • Butler MS, Clin Orthop 251, 1990 • Stinson SF, Int Radiat Oncol Biol Phys 21,1991 • Wall JE, Orthopedics, 19, 1996

14. Pathological Fracture after Radiation and Resection of Soft Tissue Sarcoma • Scarborough,CORR,389,2001 • Rate of fracture 5.6 % • Rate of nonunion 45 %

15. Pathological Fracture after Radiation and Resection of Soft Tissue Sarcoma Scarborough,CORR,389,2001 • Periosteal stripping and anterior compartment involvement were identified as significant risk factors for the femur fracture after en bloc excision and irradiation for treatment of soft tissue sarcomas of the thigh

16. Pathological Fracture after Radiation and Resection of Soft Tissue Sarcoma Scarborough,CORR,389,2001 • 16 % fracture rate if anterior compartment • 15-fold increase in risk

17. Pathological Fracture after Radiation and Resection of Soft Tissue Sarcoma Lin PP,Cancer 47,1998 • Periosteal stripping a risk factor for fracture after surgical excision and radiation of the extremity tumors

18. Pathological Fracture after Radiation and Resection of Soft Tissue Sarcoma Lin PP,Clin Orthop 352,1998 • Also reported 75% nonunion or delayed union • advocated intramedullary fixation and bone grafting

19. Pathological Fracture after Radiation and Resection of Soft Tissue Sarcoma Bell RS, Clin Orthop, 271, 1991 • Concluded that long bones have a diminished capacity to remodel according to stress after radiation therapy.

20. Pathological Fracture after Radiation and Resection of Soft Tissue Sarcoma Discussion • rate of fracture compatible with lower end of reported range • rate of non union lower than most reports

21. Pathological Fracture after Radiation and Resection of Soft Tissue Sarcoma Discussion • lower radiation dose (most cases treated preoperatively to 50gy with only close or positive margins boosted to 63gy); is this an explanation for lower nonunion rate? • avg 54Gy our pts vs avg 59gy Scarborough study; is this significant?

22. Pathological Fracture after Radiation and Resection of Soft Tissue Sarcoma

23. Pathological Fracture after Radiation and Resection of Soft Tissue Sarcoma Conclusion • Based on this series, the small number and low morbidity associated with pathological fractures in the context of irradiated and resected soft tissue sarcoma does not warrant prophylactic intramedullary fixation of the femur/tibia at the time of sarcoma resection.

24. Pathological Fracture after Radiation and Resection of Soft Tissue Sarcoma Conclusion • individualized decision • morbidity vs benefit • bone resection

25. Thank you