Anatomy Msk · Year 1 · from Anatomy Msk
Case 3: Pathologic Fracture from Metastatic Disease
Clinical Image
Source: Wikimedia Commons - Pathologic Fracture - CC BY-SA 4.0
Case Presentation
A 62-year-old man with a history of prostate cancer diagnosed 3 years ago (Gleason 4+3, treated with radical prostatectomy and radiation) presents with sudden onset of severe right arm pain while lifting a grocery bag. He reports progressive dull aching pain in the same region over the past 2 months that he attributed to overuse. Physical examination reveals significant swelling and tenderness over the mid-shaft of the right humerus with palpable crepitus. He is unable to extend his wrist or fingers (wrist drop), suggesting radial nerve involvement. Radiographs demonstrate a transverse fracture through a lytic lesion in the humeral diaphysis with cortical destruction and periosteal reaction. PSA level is elevated at 45 ng/mL (previously undetectable post-treatment). Bone scan reveals multiple areas of increased uptake in the spine and pelvis. The patient undergoes intramedullary nailing of the humerus followed by radiation therapy and initiation of androgen deprivation therapy. This case illustrates how disruption of normal bone architecture leads to structural weakness.
Key Learning Points
- Pathologic fractures occur through bone weakened by disease (tumor, infection, metabolic disorders)
- Metastatic lesions disrupt the cortical bone structure essential for load-bearing
- Prostate cancer commonly metastasizes to bone via the vertebral venous plexus (Batson's plexus)
- Lesions may be lytic (bone destruction), blastic (bone formation), or mixed
- Fractures through long bone diaphysis (compact bone) often involve the radial nerve in the spiral groove