Case: A sixty-five-year-old immunocompetent man with bilateral osteonecrosis of the hip and no prior surgical procedures or trauma was found to have a subacute Propionibacterium acnes infection of the femoral head. To our knowledge, this is the first reported case of Propionibacterium acnes infection in a native hip in the orthopaedic literature.
Conclusion: Diagnosing a subacute P. acnes infection can be challenging because of nonspecific clinical findings, normal laboratory values, and delayed growth of this organism on culture. Clinicians should maintain a high degree of suspicion as these infections are frequently missed.