Minocycline-Induced Bone Discoloration: A Case Report

Minocycline-induced black bone disease with synovial pigmentation in a patient undergoing revision anterior cruciate ligament surgery: A case report

INTRODUCTION

Long-term use of minocycline at high doses is associated with hyperpigmentation with multiple sites of involvement. While the cutaneous organs and the oral cavity are most commonly affected, bone discoloration is a rare entity.

CASE PRESENTATION

A 19-year-old male patient with a history of acne vulgaris and intermittent treatment with high dose minocycline for three years presented with recurrent anterior cruciate ligament (ACL) tear. During arthroscopic surgery, however, hyperpigmentation of the femur and synovium was observed. Abnormal tissue was biopsied and confirmed through histopathological examination to contain melanin-related minocycline pigmentation. Revision surgery was re-scheduled with no intraoperative complications and excellent long-term clinical outcomes.

CLINICAL DISCUSSION

There are several possible causes of hyperpigmentation, including hemosiderin deposition, infection, aseptic necrosis, demineralization, and metastatic disease. Black bone disease, caused by minocycline-induced hyperpigmentation, is rare. While the appearance is grossly abnormal in black bone disease, there has been no evidence suggesting that tissue integrity is compromised.

CONCLUSION

This case confirms that hyperpigmentation does not affect bone integrity and that surgical procedures can be performed safely. Knowing the adverse effects of minocycline administration could reduce inappropriate postponement of surgical procedures, thereby saving time and resources.

Black pigmentation of both forearm bones after chronic minocycline antibiotic therapy for septic nonunion. A case report and literature review

We report the case of a 28-year-old man with a septic forearm non-union treated with minocycline for 3 months. At the time of reconstructive surgery, the radius and ulna were entirely black. Surgical debridement until bleeding of both bone extremities resulted in a 5-cm defect that was filled with a cement spacer. Histology confirmed poorly vascularized bone with focal areas of acute inflammatory infiltrate at the non-union sites (highly suggestive of infection) and normal structure of the remaining diaphyseal bones, although black in color. Reconstruction with free vascularized fibula transfer was successful leading to complete bone healing. An incidental finding of minocycline-induced black bone discoloration should not change the surgeon's decision because there is no evidence of adverse effects on bone healing in the literature. Surgery can be performed safely at sites of minocycline-induced black bone pigmentation.

Case Study: An intraoperative finding of black bone disease in a podiatric surgery patient

Black bone disease has been recognised as a potential consequence of long-term treatment with tetracycline antibiotics. Largely documented affecting structures in the head and skull, there are few reported cases of black bone disease in the foot and ankle. The case of a 55 years old patient, who as a teenager, had undergone treatment with minocycline hydrochloride for chronic acne, and was found to have bone discolouration consistent with minocycline induced black bone disease (MIBBD) during the course of hallux valgus corrective surgery some 40 years later, is presented. In spite of the intraoperative findings, the patient's post-operative recovery and bone healing was uneventful. The literature on minocycline induced black bone disease is reviewed.

Black bone disease in a healing fracture

Black bone disease refers to the hyperpigmentation of bone secondary to prolonged usage of minocycline. We present a report of a 34-year-old man who underwent femoral shaft fracture fixation complicated by deep infection requiring debridement. The implants were removed 10 months later after long-term treatment with minocycline and fracture union. A refracture of the femoral shaft occurred 2 days after implant removal and repeat fixation was required. Intraoperatively, abundant heavily pigmented and dark brown bone callus was noted over the old fracture site. There was no evidence of other bony pathology and the appearance was consistent with minocycline-associated pigmentation. As far as we are aware, this is the first case of black bone disease affecting callus within the interval period of bone healing. We also discuss the relevant literature on black bone disease to bring light on this rare entity that is an unwelcomed surprise to operating orthopaedic surgeons.