Maccioni Cristobal B, Woodbridge Adam B, Balestro Jean-Christian Y, Figtree Melanie C, Hudson Bernard J, Cass Benjamin, Young Allan A
Department of Orthopaedic Surgery, Royal North Shore Hospital, Sydney, NSW, Australia; Department of Orthopaedic Surgery, North Shore Private Hospital, Mater Hospital, Sydney, NSW, Australia.
Department of Orthopaedic Surgery, Royal North Shore Hospital, Sydney, NSW, Australia.
J Shoulder Elbow Surg. 2015 Aug;24(8):1206-11. doi: 10.1016/j.jse.2014.12.026. Epub 2015 Feb 17.
Propionibacterium acnes is a recognized pathogen in postoperative shoulder infections. A recent study reported growth of P acnes in 42% of glenohumeral joints in primary shoulder arthroplasty, concluding that P acnes may cause shoulder osteoarthritis. Whether these results reflect true bacterial infection or specimen contamination is unclear. Our prospective study aimed to determine the rate of P acnes infection in arthritic shoulders using a strict specimen collection technique.
We used modified Oxford protocol to collect tissue specimens from the glenohumeral joint of 32 consecutive patients undergoing primary shoulder arthroplasty. Specimens were cultured specifically for P acnes. Diagnosis of P acnes infection required 2 or more positive cultures and histopathology compatible with infection.
Three of 32 patients had a positive culture for P acnes. Overall, 3.125% of specimens grew P acnes without histologic evidence of infection. There were no patients with P acnes infection. The difference in culture rates between patients with idiopathic osteoarthritis and those with a predisposing cause for osteoarthritis was not significant.
We found a low rate of positive cultures for P acnes, but no P acnes infection and no difference between types of osteoarthritis. These results do not support a cause-and-effect relationship between P acnes and osteoarthritis. The differing results from previous studies are likely explained by our strict specimen collection technique, reflecting different rates of contamination rather than infection. That P acnes contamination occurs in primary shoulder arthroplasty is concerning. Further studies are needed to assess the rates of contamination in shoulder surgery, its clinical effect, and to determine optimal antibiotic prophylaxis.
痤疮丙酸杆菌是术后肩部感染中公认的病原体。最近一项研究报告称，在初次肩关节置换术中，42%的肱骨头关节有痤疮丙酸杆菌生长，得出痤疮丙酸杆菌可能导致肩关节骨关节炎的结论。这些结果反映的是真正的细菌感染还是标本污染尚不清楚。我们的前瞻性研究旨在使用严格的标本采集技术确定关节炎性肩部痤疮丙酸杆菌感染率。
我们采用改良牛津方案，从32例连续接受初次肩关节置换术的患者的肱骨头关节采集组织标本。标本专门培养痤疮丙酸杆菌。痤疮丙酸杆菌感染的诊断需要2次或更多次阳性培养以及与感染相符的组织病理学检查。
32例患者中有3例痤疮丙酸杆菌培养呈阳性。总体而言，3.125%的标本生长出痤疮丙酸杆菌，但无感染的组织学证据。没有患者发生痤疮丙酸杆菌感染。特发性骨关节炎患者和有骨关节炎易感因素患者的培养率差异不显著。
我们发现痤疮丙酸杆菌培养阳性率较低，但未发现痤疮丙酸杆菌感染，且不同类型骨关节炎之间无差异。这些结果不支持痤疮丙酸杆菌与骨关节炎之间存在因果关系。先前研究结果不同可能是由于我们严格的标本采集技术，反映的是不同的污染率而非感染率。初次肩关节置换术中出现痤疮丙酸杆菌污染令人担忧。需要进一步研究评估肩部手术中的污染率、其临床影响，并确定最佳抗生素预防措施。
