Wednesday, November 2, 2016

Black bone found at total shoulder arthroplasty

Minocycline induced black bone disease: an incidental finding during total shoulder arthroplasty

These authors report a case of  minocycline-induced black bone disease, an apparently benign cause of black bone disease. The case was an incidental finding during a routine total shoulder arthroplasty. The observation of black discoloration of the glenohumeral joint surfaces were of no consequence to the implantation of a total shoulder arthroplasty using standard techniques.

Minocycline-induced bone discoloration is caused by the ability of oxidized minocycline to chelate calcium, incorporating it into normal bone. The histology of discolored bone shows normal osseous tissue, without bone necrosis, hemosiderin deposits, malignant cells, metallic debris, minocycline breakdown products, or evidence of any pathologic process as compared to discolored skin.  The underlying bone was of normal quality and the recovery has been uneventful.

Comment: Similar cases have been reported in knee arthroplasty (see this link). Surgeons should be aware of this apparently benign finding.