Pathologic Fracture : Wheeless' Textbook of Orthopaedics

- See:
- Pathologic Hip Frx
- Metastatic Tumors to Bone

- Discussion:
- fractures which occur from low energy injuries which occur thru an area of bone weakness with a pre-existing abnormality;
- injured area demonstrates distored archetecture and distored bone density;
    - Diff Dx:
        - Fibrous Dysplasia
            - Fibrous Histiocytoma
        - Gaucher's Disease
        - Giant Cell Tumor of Bone
        - Metastatic Tumors to Bone (most common)
        - Metastatic Breast Cancer:
        - Multiple Myeloma
        - Nonossifying fibroma
        - Osteogenesis Imperfecta
        - Osteomalacia
        - Osteomyelitis:
        - Osteoporosis
        - Osteopetrosis
        - Pagets Disease
        - Renal Osteodystrophy
        - Simple Bone Cyst / Unicarmeral

- Management:
- Labs:
- serum lab studies will help rule out systemic conditions;
- Sed Rate
- CBC
- Serum Calcium
- Skeletal Survey: (helps rule out pending frx in axial skeleton, femurs, and humeri);
- Bone Scan
- may reveal other bone lesions which are not evident from radiographs;
- note that some tumors such as multiple myeloma do not show increased uptake on bone scans;
- Biopsy:
- performed thru fine needle or open biopsy;
- culture for Osteomyelitis

- Prophylactic Management

prophylactic nailing of femoral lytic lesions:
- scoring system of risk (Mirels (1989))
- based on 4 characteristics: tumor location, associated pain, type of lesion (either lucent, mixed, or blastic), and lesion size;
- tumor is scored from 1 to 3 in each category and a total score is obtained that correlates to fracture risk;
- prophylactic fixation is advised for lesions with scores of higher than 8, and consideration for stabilization is considered for scores of 8.
- references:
- Metastatic disease in long bones: A proposed scoring system for diagnosing impending pathologic fractures.
- Critical evaluation of Mirels' rating system for impending pathologic fractures.

                     - Metastatic bone disease: the requirement for improvement in a multidisciplinary approach.
                     - Mirels' Rating for Humerus Lesions is Both Reproducible and Valid.
                     - Comparative analysis of risk factors for pathological fracture with femoral metastases.

Orthopaedia. Metastatic bone lesions (pathological fractures)

- Fracture Management:
- in the study by Duffy GP, et al, authors evaluated the functional results, rates of union, and complications associated w/ vascularized free fibular
transfer combined with autografting for the treatment of nonunions in previously irradiated bone;
- 17 patients w/ 18 vascularized free fib transfers + autografting for treatment of nonunion of a frx in previously irradiated bone were include;
- 8 patients had a bone neoplasm and nine, a soft-tissue neoplasm;
- dx: ewing sarcoma in 4; lymphoma, MFH, and rhabdomyosarcoma in two patients each; and cavernous hemangioma, metastatic
breast carcinoma, reticulum-cell sarcoma, myxosarcoma, hemangiopericytoma, and fibrosarcoma in one patient each.
- all patients received radiation therapy;
- average dose was 5564 centigray;
- average interval between the radiation therapy and the original fracture was 111 months;
- fracture was in the femur in thirteen patients, in the humerus in three, and in the tibia in one;
- all patients had operative or nonoperative treatment, or both, of the initial fracture, and two had iliac-crest bone-grafting after
the initial open reduction and internal fixation procedure;
- all fibular transfers were applied as onlay grafts because no nonunion was associated with a large segmental defect;
- cancellous autogenous bone graft was used as an additional graft at proximal and distal junctions of graft w/ bone and at fracture site in all patients;
- 16 of the 18 fracture sites united, after an average of 9.4 months (range, three to twenty-four months);
- 13 patients had an excellent result, one had a good result, two had a fair result, and one had a failure of treatment;
- authors suggest that microvascular fibular transfer + autografting is appropriate for difficult nonunions associated with previously irradiated bone.
- references:
- Fractures following limb-salvage surgery and adjuvant irradiation for soft-tissue sarcoma.