Genetic Pathways of Neuroregeneration in a Novel Mild Traumatic Brain Injury Model in Adult Zebrafish.

Mild traumatic brain injuries (mTBIs) are one of the most prevalent neurological disorders, and humans are severely limited in their ability to repair and regenerate central nervous system (CNS) tissue postinjury. However, zebrafish (Danio rerio) maintain the remarkable ability to undergo complete and functional neuroregeneration as an adult. We wish to extend knowledge of the known mechanisms of neuroregeneration by analyzing the differentially expressed genes (DEGs) in a novel adult zebrafish model of mTBI. In this study, a rodent weight drop model of mTBI was adapted to the adult zebrafish. A memory test showed significant deficits in spatial memory in the mTBI group. We identified DEGs at 3 and 21 days postinjury (dpi) through RNA-sequencing analysis. The resulting DEGs were categorized according to gene ontology (GO) categories. At 3 dpi, GO categories consisted of peak injury response pathways. Significantly, at 21 dpi, GO categories consisted of neuroregeneration pathways. Ultimately, these results validate a novel zebrafish model of mTBI and elucidate significant DEGs of interest in CNS injury and neuroregeneration.

Preoperative Anemia in Hindfoot and Ankle Arthrodesis.

This is a retrospective study (n = 39) evaluating the postoperative outcomes of patients with mild to moderate preoperative anemia who underwent a hindfoot and/or ankle arthrodesis. In the study, 32 patients did not have preoperative anemia, and 7 had preoperative anemia. Mortality, length of hospital stay, blood transfusions, deep-vein thrombosis, infection, time to union, malunion, delayed union, nonunion, and ulceration were of particular interest. Comparative analyses between patients with preoperative anemia and those without were performed utilizing the independent samples t-test or by the nonparametric Mann-Whitney U-test. The Fisher exact test was used to analyze categorical data. The Shapiro-Wilk test was utilized to check normality. Statistical significance was defined at a 2-sided level of P <.05. Delayed union, nonunion, and malunion were all significantly increased in patients with preoperative anemia (P = .032, P = .004, and P = .028, respectively). Accordingly, the median total number of noninfectious complications (delayed union + nonunion + malunion) in patients with preoperative anemia (0.86 ± 0.38) was significantly higher than in patients without preoperative anemia (0.063 ± 0.25; P < .001). Patients with preoperative anemia had a significantly longer length of hospital stay in days (4.14 ± 2.61). Total infection was also significantly associated with preoperative anemia (P = .001). This study clearly demonstrated that infectious complications, noninfectious complications, and length of hospital stay in hindfoot and/or ankle arthrodesis was significantly affected by preoperative anemia. Thus, consideration should be given to addressing preoperative anemia prior to hindfoot and/or ankle arthrodesis. LEVELS OF EVIDENCE: Level II Study.

Triple arthrodesis for adult acquired flatfoot.

The primary goal of triple arthrodesis for stage III and IV adult acquired flatfoot is to obtain a well-aligned plantigrade foot that will support the ankle in optimal alignment. Ancillary procedures including posterior muscle group lengthening, medial displacement calcaneal osteotomy, medial column stabilization, peroneus brevis tenotomy, or transfer and harvest of regional bone graft are often necessary to achieve adequate realignment. Image intensification is helpful in confirming optimal realignment before fixation. Results of triple arthrodesis are enhanced with adequate preparation of joint surfaces, bone graft/orthobiologics, 2-point fixation of all 3 tritarsal joints, and a vertical heel position.

Cutaneous myoepithelioma in the foot: case report.

Cutaneous myoepithelioma is a very rare, benign, subcutaneous and dermal tumor. It usually presents as a slow-growing and painless mass on the extremities. We report a case of cutaneous myoepithelioma that was located on the foot. A 68-year old woman presented with a slowly growing pain-free mass on the right third toe measuring 0.8 × 0.7 × 0.4 cm(3). We performed an elliptical excision, with histological and immunohistochemical analysis. The lesion showed dermis with cords of cytologically uniform ovoid cells with moderate amount of pale cytoplasm. No pleomorphism, mitotic activity, or necrosis was visualized. The tumor cells were positive for S-100 protein, epithelial membrane antigen and negative for smooth-muscle actin. From these findings, the tumor was diagnosed as a cutaneous myoepithelioma extending to the deep resection margin. To our knowledge, there are only 2 documented cases in the literature in English, and none have been reported in the foot and ankle literature.

The association of metatarsus adductus to the proximal fifth metatarsal Jones fracture.

This retrospective study aimed to determine if a transverse plane forefoot relationship exists in patients with Jones fractures. Anteroposterior radiographs of 30 acute Jones fractures were compared with radiographs of 30 asymptomatic control subjects. Radiographic metatarsus adductus angle measurements were analyzed with a digital software program. The reliability of the measurements was evaluated with an intra-rater study. An independent t test was used to compare the metatarsus adductus angle between the Jones fracture group and the control group. Radiographic analysis revealed the mean metatarsus adductus angle for the Jones fracture group to be 20.22° (± 6.79°) compared with a mean of 14.27° (± 4.60°) for the control group. This difference between the groups was found to be statistically significant (p < .005). The intraclass reliability coefficient (ICC = 0.9396) confirmed there was no bias in the radiographic measurements. The metatarsus adductus angle in this group of patients with Jones fractures was increased compared with the nonpathologic control group. The Jones fracture mechanism of injury and resultant lateral column overload may be intensified with an increased metatarsus adductus. This relationship should be considered a risk factor for Jones fractures and taken into consideration with respect to bone healing, treatment, and prevention.