Incidence of Venous Thromboembolism in Patients Receiving Anticoagulation for Foot and Ankle Surgery

Venous thromboembolism (VTE) is a serious medical condition that can be an unfortunate complication arising from foot and ankle surgery. Many factors may predispose a patient to a VTE event including prolonged postoperative immobilization, comorbidities, extended length of tourniquet time, and higher risk surgeries. Unfortunately, there is no clinical consensus for guidelines on VTE prophylaxis following foot and ankle surgery. In this retrospective cohort study, we present our patient population who were prophylactically anticoagulated following foot and ankle surgery along with their incidence of deep vein thrombosis and pulmonary embolism (PE). Included in the study were patients who had undergone elective and traumatic foot and ankle surgery from June 2017 to December 2018. Using retrospective data obtained we compared patient demographics, surgery type, length of tourniquet time, postoperative immobilization, type of VTE prophylaxis, and comorbidities including history of smoking, peripheral vascular disease, bleeding disorders, and patients undergoing dialysis. Five of 425 (1.2%) patients were diagnosed with a deep vein thrombosis and 1 of 425 (0.2%) patients was diagnosed with a pulmonary embolism. Risks factors statistically significant for developing a VTE in our patient population included extended periods of immobilization and an increasing patient age. We were able to conclude that routine prophylaxis for elective and traumatic foot and ankle surgery is both effective and safe for especially in older patients requiring extended immobilization. It's also important to take into consideration comorbidities, smoking history, tourniquet time, and the type of surgery that is being performed.

Gouty Tophi in Sinus Tarsi of Bilateral Feet Mimicking Synovial Sarcoma:A Case Report

Chronic gout is defined as accumulation of monosodium urate crystals in joints, cartilage, tendons, bursae, bone, and soft tissue. The foot is the most common location for acute gout flares, with the first metatarsophalangeal joint being the most frequent site of tophus formation. However, few studies have reported gouty tophus formation in the subtalar joint. Gout has been termed the "great mimicker" because of its tendency to mimic other pathologic conditions, such as pigmented villonodular synovitis and synovial sarcoma. Herein, we present a rare case of chronic tophaceous gout in the sinus tarsi in both feet in a 23-year-old healthy male, with extensive bony erosions mimicking pigmented villonodular synovitis and synovial sarcoma. We discuss the clinical presentation, distinguishing radiologic characteristics, surgical procedures, and outcome regarding this unique presentation.

Silencing of hypoxia-inducible factor-1α gene attenuates chronic ischemic renal injury in two-kidney, one-clip rats

Overactivation of hypoxia-inducible factor (HIF)-1α is implicated as a pathogenic factor in chronic kidney diseases (CKD). However, controversy exists regarding the roles of HIF-1α in CKD. Additionally, although hypoxia and HIF-1α activation are observed in various CKD and HIF-1α has been shown to stimulate fibrogenic factors, there is no direct evidence whether HIF-1α is an injurious or protective factor in chronic renal hypoxic injury. The present study determined whether knocking down the HIF-1α gene can attenuate or exaggerate kidney damage using a chronic renal ischemic model. Chronic renal ischemia was induced by unilaterally clamping the left renal artery for 3 wk in Sprague-Dawley rats. HIF-1α short hairpin (sh) RNA or control vectors were transfected into the left kidneys. Experimental groups were sham+control vector, clip+control vector, and clip+HIF-1α shRNA. Enalapril was used to normalize blood pressure 1 wk after clamping the renal artery. HIF-1α protein levels were remarkably increased in clipped kidneys, and this increase was blocked by shRNA. Morphological examination showed that HIF-1α shRNA significantly attenuated injury in clipped kidneys: glomerular injury indices were 0.71 ± 0.04, 2.50 ± 0.12, and 1.34 ± 0.11, and the percentage of globally damaged glomeruli was 0.02, 34.3 ± 5.0, and 6.3 ± 1.6 in sham, clip, and clip+shRNA groups, respectively. The protein levels of collagen and α-smooth muscle actin also dramatically increased in clipped kidneys, but this effect was blocked by HIF-1α shRNA. In conclusion, long-term overactivation of HIF-1α is a pathogenic factor in chronic renal injury associated with ischemia/hypoxia.

Silencing of hypoxia-inducible factor-1α gene attenuated angiotensin II-induced renal injury in Sprague-Dawley rats

Although it has been shown that upregulation of hypoxia-inducible factor (HIF)-1α is protective in acute ischemic renal injury, long-term overactivation of HIF-1α is implicated to be injurious in chronic kidney diseases. Angiotensin II (Ang II) is a well-known pathogenic factor producing chronic renal injury and has also been shown to increase HIF-1α. However, the contribution of HIF-1α to Ang II-induced renal injury has not been evidenced. The present study tested the hypothesis that HIF-1α mediates Ang II-induced renal injury in Sprague-Dawley rats. Chronic renal injury was induced by Ang II infusion (200 ng/kg per minute) for 2 weeks in uninephrectomized rats. Transfection of vectors expressing HIF-1α small hairpin RNA into the kidneys knocked down HIF-1α gene expression by 70%, blocked Ang II-induced HIF-1α activation, and significantly attenuated Ang II-induced albuminuria, which was accompanied by inhibition of Ang II-induced vascular endothelial growth factor, a known glomerular permeability factor, in glomeruli. HIF-1α small hairpin RNA also significantly improved the glomerular morphological damage induced by Ang II. Furthermore, HIF-1α small hairpin RNA blocked Ang II-induced upregulation of collagen and α-smooth muscle actin in tubulointerstitial region. There was no difference in creatinine clearance and Ang II-induced increase in blood pressure. HIF-1α small hairpin RNA had no effect on Ang II-induced reduction in renal blood flow and hypoxia in the kidneys. These data suggested that overactivation of HIF-1α-mediated gene regulation in the kidney is a pathogenic pathway mediating Ang II-induced chronic renal injuries, and normalization of overactivated HIF-1α may be used as a treatment strategy for chronic kidney damages associated with excessive Ang II.