Adolescents with obesity have increased risk of type 2 diabetes and metabolic syndrome (MetS). Pancreatic fat has been related to these conditions; however, little is known about associations in pediatric obesity. The present study was designed to explore these associations further. We examined 116 subjects, 90 with obesity. Anthropometry, MetS, blood samples, and oral glucose tolerance tests were assessed using standard techniques. Pancreatic fat fraction (PFF) and other fat depots were quantified using magnetic resonance imaging. The PFF was elevated in subjects with obesity. No association between PFF and body mass index-standard deviation score (BMI-SDS) was found in the obesity subcohort. Pancreatic fat fraction correlated to Insulin Secretion Sensitivity Index-2 and Homeostatic Model Assessment of Insulin Resistance in simple regression; however, when using adjusted regression and correcting for BMI-SDS and other fat compartments, PFF correlated only to visceral adipose tissue and fasting glucose. Highest levels of PFF were found in subjects with obesity and MetS. In adolescents with obesity, PFF is elevated and associated to MetS, fasting glucose, and visceral adipose tissue but not to beta-cell function, glucose tolerance, or BMI-SDS. This study demonstrates that conclusions regarding PFF and its associations depend on the body mass features of the cohort.

Background: In the ongoing development of bioresorbable implants, there has been a particular focus on magnesium (Mg)-based alloys. Several Mg alloys have shown promising properties, including a lean, bioresorbable magnesium-zinc-calcium (Mg-Zn-Ca) alloy designated as ZX00. To our knowledge, this is the first clinically tested Mg-based alloy free from rare-earth elements or other elements. Its use in medial malleolar fractures has allowed for bone healing without requiring surgical removal. It is thus of interest to assess the resorption behavior of this novel bioresorbable implant. Questions/purposes: (1) What is the behavior of implanted Mg-alloy (ZX00) screws in terms of resorption (implant volume, implant surface, and gas volume) and bone response (histologic evaluation) in a sheep model after 13 months and 25 months? (2) What are the radiographic changes and clinical outcomes, including patient-reported outcome measures, at a mean of 2.5 years after Mg-alloy (ZX00) screw fixation in patients with medial malleolar fractures? Methods: A sheep model was used to assess 18 Mg-alloy (ZX00) different-length screws (29 mm, 24 mm, and 16 mm) implanted in the tibiae and compared with six titanium-alloy screws. Micro-CT was performed at 13 and 25 months to quantify the implant volume, implant surface, and gas volume at the implant sites, as well as histology at both timepoints. Between July 2018 and October 2019, we treated 20 patients with ZX00 screws for medial malleolar fractures in a first-in-humans study. We considered isolated, bimalleolar, or trimalleolar fractures potentially eligible. Thus, 20 patients were eligible for follow-up. However, 5% (one patient) of patients were excluded from the analysis because of an unplanned surgery for a pre-existing osteochondral lesion of the talus performed 17 months after ZX00 implantation. Additionally, another 5% (one patient) of patients were lost before reaching the minimum study follow-up period. Our required minimum follow-up period was 18 months to ensure sufficient time to observe the outcomes of interest. At this timepoint, 10% (two patients) of patients were either missing or lost to follow-up. The follow-up time was a mean of 2.5 ± 0.6 years and a median of 2.4 years (range 18 to 43 months). Results: In this sheep model, after 13 months, the 29-mm screws (initial volume: 198 ± 1 mm³) degraded by 41% (116 ± 6 mm³, mean difference 82 [95% CI 71 to 92]; p < 0.001), and after 25 months by 65% (69 ± 7 mm³, mean difference 130 [95% CI 117 to 142]; p < 0.001). After 13 months, the 24-mm screws (initial volume: 174 ± 0.2 mm³) degraded by 51% (86 ± 21 mm³, mean difference 88 [95% CI 52 to 123]; p = 0.004), and after 25 months by 72% (49 ± 25 mm³, mean difference 125 [95% CI 83 to 167]; p = 0.003). After 13 months, the 16-mm screws (initial volume: 112 ± 5 mm³) degraded by 57% (49 ± 8 mm³, mean difference 63 [95% CI 50 to 76]; p < 0.001), and after 25 months by 61% (45 ± 10 mm³, mean difference 67 [95% CI 52 to 82]; p < 0.001). Histologic evaluation qualitatively showed ongoing resorption with new bone formation closely connected to the resorbing screw without an inflammatory reaction. In patients treated with Mg-alloy screws after a mean of 2.5 years, the implants were radiographically not visible in 17 of 18 patients and the bone had homogenous texture in 15 of 18 patients. No clinical or patient-reported complications were observed. Conclusion: In this sheep model, Mg-alloy (ZX00) screws showed a resorption to one-third of the original volume after 25 months, without eliciting adverse immunologic reactions, supporting biocompatibility during this period. Mg-alloy (ZX00) implants were not detectable on radiographs after a mean of 2.5 years, suggesting full resorption, but further studies are needed to assess environmental changes regarding bone quality at the implantation site after implant resorption. Clinical Relevance: The study demonstrated successful healing of medial malleolar fractures using bioresorbable Mg-alloy screws without clinical complications or revision surgery, resulting in pain-free ankle function after 2.5 years. Future prospective studies with larger samples and extended follow-up periods are necessary to comprehensively assess the long-term effectiveness and safety of ZX00 screws, including an exploration of limitations when there is altered bone integrity, such as in those with osteoporosis. Additional use of advanced imaging techniques, such as high-resolution CT, can enhance evaluation accuracy.

Addressing non-unions involves stabilizing the affected area through osteosynthesis and improving bone biology using bone grafts. However, there is no consensus on the optimal treatment method. This study aims to compare outcomes of non-union surgery using conventional treatment methods (metal hardware ± graft) versus osteosynthesis with the human allogeneic cortical bone screw (Shark Screw^®) alone or in combination with a metallic plate. Thirty-four patients underwent conventional treatment, while twenty-eight cases received one or more Shark Screws^®. Patient demographics, bone healing, time to bone healing, and complications were assessed. Results revealed a healing rate of 96.4% for the Shark Screw^® group, compared to 82.3% for the conventionally treated group. The Shark Screw^® group exhibited a tendency for faster bone healing (9.4 ± 3.2 vs. 12.9 ± 8.5 weeks, p = 0.05061). Hardware irritations led to six metal removals in the conventional group versus two in the Shark Screw^® group. The Shark Screw^® emerges as a promising option for personalized non-union treatment in the foot, ankle, and select lower leg cases, facilitating effective osteosynthesis and grafting within a single construct and promoting high union rates, low complications, and a rapid healing process.

Aim: Internal fixation of femoral neck fractures is a widely used procedure that is comparatively less invasive and faster than hip replacement. While head preserving internal fixation of these fractures are still preferred where feasible, a faster recovery and lower reoperation rates make arthroplasty increasingly more appealing, in spite of being a more invasive option. Our aim was to determine the reoperation rate after internal fixation at our institution and to explore relevant risk factors in a geriatric population. Methods: This monocentric follow-up study was conducted analyzing 116 patients aged 65 and older with femoral neck fractures who were surgically treated with either cancellous screws or dynamic hip screws between 2010 and 2017. We retrospectively collected longitudinal data from our patient database, supplemented by a telephone survey, with a follow-up period of at least 18 months. Results: Twenty reoperations, due to either a failure of fixation, avascular necrosis, or posttraumatic osteoarthritis, were identified in our cohort, which constituted a reoperation rate of 17.2% (20/116). Fracture displacement was significantly associated with the reoperation risk (HR 8, CI 3-20; P < .001). The reoperation rate was 52.2% in displaced fractures vs 8.9% in undisplaced fractures. No link was found between the reoperation rate and gender, age, BMI, ASA score, type of implant, quality of internal fixation, type of living accommodation, and pre-fracture mobility. Conclusion: Internal fixation has been found to be an effective option in elderly patients with undisplaced fractures regardless of their specific age, cognitive ability or physical condition. In displaced fractures the reoperation rate was found to be high, therefore a primary hip replacement should be recommended.

Antibiotic-loaded bone cements (ALBCs) are used as spacers in two-stage revision arthroplasty for periprosthetic joint infection. We previously described a new technique applying vancomycin powder coating to custom-made cements. To our best knowledge, this method of superficial vancomycin coating (SVC) has not been assessed before. We therefore performed an in-vitro study to determine: (1) whether manually applied SVC strengthened the cements' antibiotic effect; and (2) whether the mechanical requirements for the cements were fulfilled. SVC increases the antibiotic effect of cement within the first 24hours. Cuboid blocks were produced from two commercially available acrylic ALBCs (Palacos R+G and Copal G+V) with and without SVC. Each block was eluted in phosphate-buffered saline at 37°C. Eluates obtained at 1, 2, 3, 4, 5, 10, 15, 30 and 60minutes and 3, 6 and 24hours were evaluated against Staphylococcus aureus (Palacos, Copal) and methicillin-resistant Staphylococcus aureus (MRSA) (Copal) using zone of inhibition tests. Mechanical test results (bending modulus, bending strength) were compared to ISO requirements (≥1800MPa, ≥50MPa). Palacos with SVC produced significantly greater zones of inhibition against Staphylococcus aureus than Palacos without SVC (p=0.002). Copal with SVC showed greater zones of inhibition against both Staphylococcus aureus and MRSA (p=0.002). The antibiotic effect was enhanced by SVC in both cements at every time point within 24hours. The bending modulus and bending strength of Palacos with SVC (2089±166MPa, 60.8±2.6 MPA) and Copal with SVC (2283±195MPa, 56.9±2.4MPa) were significantly above ISO requirements. SVC boosts the antibiotic effect of ALBCs in the first 24hours, while maintaining sufficient stability. These findings endorse SVC as a promising additive in septic revision surgery. III; case control study.

Introduction. Popliteal artery entrapment syndrome (PAES) is caused by compression of the popliteal artery (PA) due to deranged myotendinous structures. It can be asymptomatic or may present with exercise intolerance, claudication, or even limb-threatening ischemia. The clinical picture depends on the anatomy and degree of vascular compromise. Case Description. We report a case of a 17-year-old Caucasian male with PAES Type II presenting with intermittent claudication and progression towards acute limb ischemia. Diagnostics. MRI and MRA helped identifying the aberrant anatomy and thrombotic occlusion. Doppler ultrasound and conventional angiography have also been employed in a stepwise approach. Intervention. The thrombus at the site of occlusion was removed by the use of catheter-directed lysis. Subsequently, popliteal artery release was achieved by myotomy of the aberrant medial head of gastrocnemius muscle (MHGM) and muscle transfer to the medial femoral condyle. A three-month regimen of 60mg edoxaban was recommended after surgery. Outcome. Surgical correction of the anomalous anatomy and postoperative anticoagulation led to freedom of symptoms. Lesson. Clinical presentation of PAES mimicking peripheral artery occlusive disease is very rare but potentially limb-threatening. PAES should be considered in young and otherwise healthy individuals.