On the faculty
Dr Kenneth Cutbush was faculty at the Royal North Shore Shoulder Symposium in Sydney in September 2015, and gave two talks.
B type glenoid management
The first concerned total shoulder replacement in patients with difficult glenoid anatomy, where the socket has worn unevenly, and the respective roles of anatomic and reverse total shoulder replacement in those shoulders.
The glenoid is the socket of the shoulder, a shallow dish on the outer edge of the shoulder blade. In arthritis it often wears away unevenly rather than uniformly, most commonly at the back, so the ball comes to sit further back than it should and the remaining socket surface ends up tilted. That makes the operation harder, because an implant fixed to a tilted surface is loaded off centre.
The choice between an anatomic replacement, which keeps the normal ball and socket arrangement and depends on an intact rotator cuff, and a reverse replacement, which swaps the two over and relies on the deltoid muscle, turns partly on how much correctable bone is left and partly on the state of the tendons. Classification systems such as the B type description exist to give surgeons a common language for those wear patterns. Individual results vary.
Avoiding infection in shoulder arthroplasty
The second covered research on preventing infection after shoulder joint replacement, with particular attention to Propionibacterium acnes, now reclassified as Cutibacterium acnes. This organism lives within the sebaceous glands of the skin around the shoulder and is recognised as a frequent cause of infection after shoulder arthroplasty specifically.
Because it sits inside the glands rather than on the surface, it is not fully removed by the skin preparation used immediately before an operation, which is why it features in shoulder surgery more than in hip or knee surgery. Infection around an implant is a serious problem to treat, since bacteria on an implant surface are difficult to clear with antibiotics alone, so most of the effort goes into prevention.
Published work reports that topical benzoyl peroxide applied by patients for 48 hours before surgery reduces the numbers of this organism on the skin. The aim of such protocols is to reduce its contribution to post-operative infection. Individual results vary.
Related information
- Our anatomic total shoulder replacement and reverse total shoulder replacement pages
- Our shoulder arthritis page
- Our post on preventing infection in shoulder replacement surgery
- Our post on the benefits of benzoyl peroxide