A Rare Case of Staphylococcus Caprae Periprosthetic Hip Infection with Unusual Clinical Presentation
Authors:   [1] Adult Reconstruction and Joint Replacement Service, Division of Sports Traumatology and Joint Surgery, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Largo Agostino Gemelli 8, Roma, RM 00168, Italy, [2] Università Cattolica del Sacro Cuore, Largo Francesco Vito 1, Roma, RM, 00168, Italy., Grassa Daniele , Cavola Francesco ,   [1] Adult Reconstruction and Joint Replacement Service, Division of Sports Traumatology and Joint Surgery, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Largo Agostino Gemelli 8, Roma, RM 00168, Italy, [2] Università Cattolica del Sacro Cuore, Largo Francesco Vito 1, Roma, RM, 00168, Italy., Giuliani Alessandro ,   [1] Adult Reconstruction and Joint Replacement Service, Division of Sports Traumatology and Joint Surgery, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Largo Agostino Gemelli 8, Roma, RM 00168, Italy, [2] Università Cattolica del Sacro Cuore, Largo Francesco Vito 1, Roma, RM, 00168, Italy., Rajeev Rashma ,   Università Cattolica del Sacro Cuore, Largo Francesco Vito 1, Roma, RM, 00168, Italy., Singlitico Alessandro ,   [1] Adult Reconstruction and Joint Replacement Service, Division of Sports Traumatology and Joint Surgery, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Largo Agostino Gemelli 8, Roma, RM 00168, Italy, [2] Università Cattolica del Sacro Cuore, Largo Francesco Vito 1, Roma, RM, 00168, Italy., De Martino Ivan ,   [1] Adult Reconstruction and Joint Replacement Service, Division of Sports Traumatology and Joint Surgery, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Largo Agostino Gemelli 8, Roma, RM 00168, Italy, [2] Università Cattolica del Sacro Cuore, Largo Francesco Vito 1, Roma, RM, 00168, Italy.
Published: January 2025

Introduction: Total hip arthroplasty (THA) surgeries are rapidly increasing due to an aging population, leading to an increase in degenerative hip osteoarthritis. However, 1% of these patients go through prosthetic joint infection (PJI), which gives rise to implant failure with prolonged periods of patient incapacitation and higher mortality risk.

Case Report: In this article, we report an unusual case of a 62-year-old male who developed a PJI 7 months after a THA. The patient complained of groin, buttock pain, and swelling. He underwent MRI examination, which revealed the presence of a voluminous three-lobed formation with liquid content located around the prosthesis. After several attempts where microbiological samples reported negative results, a microbiological sample came out positive for Staphylococcus Caprae at the time of femoral component sonication. S. caprae is a Gram-positive bacillus belonging to the Staphylococcus spp. It is most commonly found as a commensal in goats and sheep, but it is a rare pathogen in human infections. The patient underwent two-stage revision surgery, resulting in the total resolution of the infection.

Conclusion: Staphylococcus Caprae still remains an unusual cause of infection. We report the 11th hip PJI due to S. caprae successfully treated with a two-stage exchange protocol.

Keywords: orthopedic implant-related infection, antibiotic treatment, total hip arthroplasty, periprosthetic joint infection, Staphylococcus Caprae, PJIs, two-stage revision.