Background: Antegrade intramedullary (IM) nailing for skeletally immature femur fractures can damage the capital femoral epiphysis blood supply, leading to avascular necrosis (AVN) of the femoral head. Reported AVN rates are 2% for piriformis entry and 1.4% for trochanteric entry. None of previous reports described IM lengthening nails for limb lengthening procedures. We have used self-lengthening telescopic nails with a proximal Herzog bend and standard trochanteric entry for femoral lengthening in children. The purpose of this study is to determine whether trochanteric entry IM lengthening nails can be used safely (no AVN or proximal femoral deformity) in the skeletally immature femur. Methods: A retrospective review was performed between 2004 and 2014 to determine all skeletally immature patients younger than 18 years of age who had a reamed IM lengthening nail inserted through the greater trochanter, with at least 1-year follow-up. Results: Thirty-one femurs were lengthened in 28 patients (17 males and 11 females). The etiology was congenital femoral deficiency (10), achondroplasia (6), post-traumatic (5), hemihypertrophy (3), Ollier disease (2), and miscellaneous (5). An attending surgeon was present for all procedures. Mean age at time of surgery was 12.9 years (range, 7 to 17 y). Mean follow-up was 3.5 years (range, 1.4 to 9 y). The average amount of lengthening was 5.4 cm (range, 3 to 6.7 cm). Twenty-four nails were 10.7 mm in diameter. Seven nails were 12.5 mm in diameter. Intramedullary skeletal kinetic distractor was used in 18 femurs and PRECICE in 13 femurs. Ten segments (7 intra-medullary skeletal kinetic distractor; 3 PRECICE) experienced 13 complications. None of the patients developed AVN or proximal femoral deformity. Conclusions: IM lengthening nails inserted through the greater trochanter may be utilized in skeletally immature patients without increased risk of AVN of the femoral head or proximal femoral deformity. Larger trials would be helpful to confirm our hypothesis. We recommend careful surgical technique with liberal use of the image intensifier to avoid trauma to the femoral head blood supply. Level of Evidence: Level IV-therapeutic.

Background In a surgical setting, COVID-19 patients may trigger in-hospital outbreaks and have worse postoperative outcomes. Despite these risks, there have been no consistent statements on surgical guidelines regarding the perioperative screening or management of COVID-19 patients, and we do not have objective global data that describe the current conditions surrounding this issue. This study aimed to clarify the current global surgical practice including COVID-19 screening, preventive measures and in-hospital infection under the COVID-19 pandemic, and to clarify the international gaps on infection control policies among countries worldwide. Methods During April 2-8, 2020, a cross-sectional online survey on surgical practice was distributed to surgeons worldwide through international surgical societies, social media and personal contacts. Main outcome and measures included preventive measures and screening policies of COVID-19 in surgical practice and centers’ experiences of in-hospital COVID-19 infection. Data were analyzed by country’s cumulative deaths number by April 8, 2020 (high risk, >5000; intermediate risk, 100-5000; low risk, <100). Results A total of 936 centers in 71 countries responded to the survey (high risk, 330 centers; intermediate risk, 242 centers; low risk, 364 centers). In the majority (71.9%) of the centers, local guidelines recommended preoperative testing based on symptoms or suspicious radiologic findings. Universal testing for every surgical patient was recommended in only 18.4% of the centers. In-hospital COVID-19 infection was reported from 31.5% of the centers, with higher rates in higher risk countries (high risk, 53.6%; intermediate risk, 26.4%; low risk, 14.8%; P < 0.001). Of the 295 centers that experienced in-hospital COVID-19 infection, 122 (41.4%) failed to trace it and 58 (19.7%) reported the infection originating from asymptomatic patients/staff members. Higher risk countries adopted more preventive measures including universal testing, routine testing of hospital staff and use of dedicated personal protective equipment in operation theatres, but there were remarkable discrepancies across the countries. Conclusions This large international survey captured the global surgical practice under the COVID-19 pandemic and highlighted the insufficient preoperative screening of COVID-19 in the current surgical practice. More intensive screening programs will be necessary particularly in severely affected countries/institutions. Study registration Registered in ClinicalTrials.gov: NCT04344197

An important element of artificial skin is a tissue scaffold that allows for fast host regeneration. We present a microfabrication strategy, based on gelling collagen-based components inside a microfluidic device, that produces well-controlled pore sizes inside the scaffold. This strategy can produce finely patterned tissue scaffolds of clinically relevant dimensions suitable for surgical handling. Compared to porous collagen-based sponges produced by lyophilization, microfabricated tissue scaffolds preserve the fibrous structure and ligand density of natural occurring collagen. A fibroblast migration assay revealed fast cellular migration through the pores, which is desired for rapid tissue ingrowth. Finally, we also demonstrate a strategy to use this microfabrication technique to build anatomically accurate, multi-component skin substitutes in a cost-effective manner.

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