Unusual presentation of obturator hernia: A case report of knee pain mimicking musculoskeletal condition

BACKGROUND: Obturator hernia is a rare type of pelvic hernia that often presents with vague symptoms that can easily be confused with other conditions. Delayed diagnosis can lead to increased morbidity and complications.

CASE PRESENTATION: A 67-year-old female with a history of rheumatoid arthritis presented with escalating right knee pain, unresponsive to increasing doses of opioids. She also reported mild abdominal discomfort. A knee X-ray was unremarkable, but an abdominopelvic CT scan revealed an incarcerated obturator hernia. Emergent laparoscopic transabdominal pre-peritoneal (TAPP) repair was performed, leading to significant postoperative improvement in her knee pain.

DISCUSSION: This case highlights the unusual presentation of obturator hernia with referred knee pain, which could often be misdiagnosed as a musculoskeletal issue. The likely mechanism is obturator nerve impingement caused by the hernia, and surgical intervention successfully resolved the symptoms.

CONCLUSION: Clinicians should consider obturator hernia in the differential diagnosis of unexplained knee pain, particularly in patients with risk factors like advanced age, low body weight and the female gender, to avoid delayed diagnosis and prevent serious complications.