BACKGROUND: Minocycline-induced pigmentation of bone (black bone) is well described in tooth-bearing intra-oral bone, but is less known in periarticular bone in patients who have undergone total joint arthroplasty. On a retrospective basis, we investigated the short-term clinico-radiological results of total joint arthroplasties in which the patient developed minocycline-induced periarticular black bone. METHODS: We found 5 cases (0.08%), in 4 patients, of periarticular bone pigmentation revealed during total joint arthroplasties (2 hips, 2 knees, and 1 ankle) in our series of total joint surgeries (6,548 cases) over a 10-year time period in our 3 institutes. Their mean age was 56 years at surgery. All patients had received long-term minocycline treatment. Mean dosage and duration of minocycline was 160 mg/day and 2.2 years, respectively. Minocycline had been prescribed for reactive arthritis (one), rheumatoid arthritis (two) and late infection after total joint arthroplasty (two patients). Mean follow-up period was 3.4 years after the surgeries. RESULTS: All cases had black or brown pigmentation in the periarticular bones during the surgery. There was no pigmentation in the cartilage or soft tissues of the joints. The mean Japanese Orthopaedic Association (JOA) score or Japanese Society for Surgery of the Foot (JSSF) scale for rheumatoid arthritis foot and ankle joints at latest follow-up (case 1, 66; case 2, 87; case 3, 77; case 4, 77; case 5, 80) improved compared to those of pre-surgery (case 1, 47; case 2, 45; case 3, 55; case 4, 34; case 5, 55). No implant loosening was noted on radiographic examination during the follow-up period. No abnormal bone formation, bone necrosis, hemosiderin deposition, malignancy or metallic debris was found on histological examination. CONCLUSIONS: No clinico-radiological symptoms of total joint arthroplasties showed in the patients with minocycline-induced periariticular black bone in the short-term. Systemic minocycline treatment has the potential to induce significant black pigmentation of many tissues. In particular, minocycline-induced pigmentation of periarticular bone may be accelerated by inflammation due to rheumatic or pyogenic arthritis. Surgeons should recognize the risk of bone pigmentation in inflamed joints due to the systemic treatment of minocycline and explore its influence on periarticular bone and total joint arthroplasty in the long-term.
Adult ; Aged ; Aged, 80 and over ; Anti-Bacterial Agents/*adverse effects/therapeutic use ; Antibiotic Prophylaxis/adverse effects ; Arthritis/drug therapy/*pathology/prevention & control ; Arthroplasty, Replacement/*methods ; Bone and Bones/*drug effects/pathology ; Female ; Humans ; Male ; Middle Aged ; Minocycline/*adverse effects/therapeutic use ; Retrospective Studies ; Skin/pathology ; Skin Pigmentation

OBJECTIVETo investigate the effects of oral administration of type II collagen (CII) on adjuvant arthritis (AA) in rats and its mechanisms, and to compare the effects of CII with those of the Chinese traditional medicine Tripterygium Polyglycoside administered similarly.

METHODSArthritis was induced in rats by immunization using Freund's complete adjuvant (FCA). After feeding rats either soluble CII or Tripterygium Polyglycoside, changes in degree of articular swelling and articular histological findings were observed in AA rats. Some correlative immunological indexes were measured, including delayed type hypersensitivity (DTH) reaction, anti-collagen and anti-Mycobacterium tuberculosis (MT) antibody in serum, and levels of IFN-gamma and TNF-alpha in articular steep in rats.

RESULTSOral administration of CII was able to alleviate both distinctly articular and general symptoms in AA rats, suppress synovium hyperplasia and inflammatory cells infiltration in arthrosis capsule. The effects brought about by CII were stronger than those by Tripterygium Polyglycoside. Oral administration of CII inhibited antigen-specific immune response, such as DTH and antibody reaction to CII. In addition, the expression of IFN-gamma and TNF-alpha in joints were locally downregulated.

CONCLUSIONSThe therapeutic effect of oral administration of CII is obvious on adjuvant arthritis in rats. Its remedial mechanisms are likely related to the downregulation of both IFN-gamma and TNF-alpha, and the suppression of cell immunity.

Administration, Oral ; Animals ; Antibodies ; blood ; Arthritis, Experimental ; drug therapy ; immunology ; Collagen Type II ; therapeutic use ; Hypersensitivity, Delayed ; prevention & control ; Immune Tolerance ; Interferon-gamma ; biosynthesis ; Male ; Mycobacterium tuberculosis ; immunology ; Phytotherapy ; Rats ; Rats, Sprague-Dawley ; Synovial Membrane ; pathology ; Tripterygium ; Tumor Necrosis Factor-alpha ; biosynthesis