Minocycline-Induced Black Bone Disease in Foot and Ankle Surgery: A Case Report.

BACKGROUND: Bone and periarticular tissue discoloration can be an unexpected finding that is often disconcerting for surgeons and may alter surgical plans and overall patient management. Common causes of bone discoloration include infection, avascular necrosis, and bone inflammation. Minocycline-induced black bone disease is a rare and relatively benign abnormality encountered in foot and ankle surgery that can cause significant black, blue, and gray discoloration of bone. METHODS: Unanticipated intraoperative findings of diffuse black, blue, and gray bone discoloration during an elective forefoot operation raised concern for a metabolically malignant process and prompted the conversion of plans for a first metatarsophalangeal joint implant arthroplasty to a Keller arthroplasty. The plan for proximal interphalangeal joint arthroplasties of the lesser digits were continued as planned. Bone specimens were sent for pathologic analysis. RESULTS: Postoperative analysis identified chronic use of a minocycline for acne vulgaris. Pathologic analysis of the specimens ruled out malignant processes. Altogether, the data available led to the diagnosis of minocycline-induced black bone disease. Since the last follow-up, the patient has healed well without complications. CONCLUSIONS: Our case report underscores the importance of including the chronic use of tetracyclines in medical history intake during preoperative visits to assist the surgeon in intraoperative decision-making.

How Important Is a Lesser Metatarsal Osteotomy in Preventing Second Hammertoe Recurrence?

Hammertoes with greater preoperative transverse plane deformity are more likely to recur after corrective surgery; however, it is unclear whether this represents an inherent (fixed, nonmodifiable) risk, or whether steps can be taken intraoperatively to mitigate this risk. In this study, we examined whether transverse plane transposition and/or shortening of the second metatarsal during second hammertoe surgery influenced recurrence. We performed a secondary analysis of pre-existing data from patients that had previously undergone second hammertoe surgery at our institution between January 1, 2011 and December 31, 2013. One hundred two patients (137 toes) were followed for a mean 28 ± 7.8 months postoperatively. Thirty-seven toes required, at the surgeon's discretion, an additional/concomitant Weil metatarsal osteotomy. Magnitude of transverse plane transposition and shortening of the second metatarsal, and joint angular measurements were obtained from the second metatarsophalangeal joint on weightbearing AP radiographs preoperatively and at 6 to 10 weeks postoperatively. Cox regression analysis was used to identify predictors of hammertoe recurrence using these new variables and a set of known predictors. In the final regression model, failure to establish a satisfactory postoperative metatarsal parabola (i.e., long second metatarsal; Nilsonne values <-4 mm, multivariate hazards ratio [HR] 1.96, p = .097), and intraoperative lateral transposition of the metatarsal head (multivariate HR 3.45, p = .028) seemed to confer additional risk for hammertoe recurrence. We conclude that shortening osteotomies may be assistive in some individuals, while further inquiry is still needed to determine whether similar benefits can be derived from medial head transposition in medial toe deformities.

Management of the diabetic foot.

The increasing prevalence of diabatic foot ulcers (DFUs) is not only costly, but carries a large mortality burden. In this article, we discuss important traditional concepts in the management of DFUs and elaborate on how new technologies have expanded our ability to treat DFUs effectively. New supplies and wound care products have been developed to target the following traditional areas of focus: tissue, infection/inflammation, moisture, and edge. Offloading strategies have grown from standard orthotics or insoles to total contact casting and three-dimensional-printed orthotics to produce the optimum material stiffness for each patient. The concepts of pressure and temperature monitoring have led to the development of multiple devices that transmit continuous monitoring in real time, giving a dynamic picture of plantar stress and training patients in new walking strategies for self-offloading. Surgical approaches have also evolved from the classic surgical debridement and correcting deformities that cause friction to creation of acellular and bio-printed cellular skin substitutes that can be used for grafting. Surveillance and long-term follow-up with a multidisciplinary team have also changed in the face of smartphones and watches that allow patients to monitor themselves in real time with daily prompts and reminders to shape desired behaviors in between clinic visits. Modern technology is changing management of DFUs by expanding on traditional concepts and improving standard therapies.

BK channel density is regulated by endoplasmic reticulum associated degradation and influenced by the SKN-1A/NRF1 transcription factor.

Ion channels are present at specific levels within subcellular compartments of excitable cells. The regulation of ion channel trafficking and targeting is an effective way to control cell excitability. The BK channel is a calcium-activated potassium channel that serves as a negative feedback mechanism at presynaptic axon terminals and sites of muscle excitation. The C. elegans BK channel ortholog, SLO-1, requires an endoplasmic reticulum (ER) membrane protein for efficient anterograde transport to these locations. Here, we found that, in the absence of this ER membrane protein, SLO-1 channels that are seemingly normally folded and expressed at physiological levels undergo SEL-11/HRD1-mediated ER-associated degradation (ERAD). This SLO-1 degradation is also indirectly regulated by a SKN-1A/NRF1-mediated transcriptional mechanism that controls proteasome levels. Therefore, our data indicate that SLO-1 channel density is regulated by the competitive balance between the efficiency of ER trafficking machinery and the capacity of ERAD.