Bilateral protusio acetabuli following pelvic irradiation

Area of Science:

• Orthopedic Surgery
• Oncology
• Radiology

Background:

• Pelvic irradiation is a common treatment for various cancers, including transitional cell carcinoma of the prostatic urethra.
• Complications of pelvic irradiation can affect multiple organ systems, but hip joint abnormalities are infrequently reported.

Observation:

• A 77-year-old male patient presented with bilateral protrusio acetabuli three years post-pelvic irradiation.
• No evidence of metastatic disease or concurrent systemic arthritis was found.
• Aseptic necrosis of the acetabular bone was suspected as the etiology.

Findings:

• Gross and pathological examination revealed aseptic necrosis of both femoral heads.
• Prominent pathological findings included vascular fibrosis and eosinophilia in synovial fluid and joint tissue.
• This case highlights protrusio acetabuli as a rare complication of pelvic irradiation.

Implications:

• This case underscores the importance of considering radiation-induced osteonecrosis in patients developing hip abnormalities after pelvic radiotherapy.
• Further research may be warranted to elucidate the precise mechanisms and long-term sequelae of pelvic irradiation on hip joint integrity.
• Awareness among clinicians is crucial for early diagnosis and management of this infrequent complication.