BackgroundMagnesium alloys have recently been rediscovered as biodegradable implants in musculoskeletal surgery. This study is an ex-vivo trial to evaluate the imaging characteristics of magnesium implants in different imaging modalities as compared to conventional metallic implants.MethodsA CE-approved magnesium Herbert screw (MAGNEZIX®) and a titanium screw of the same dimensions (3.2x20 mm) were imaged using different modalities: digital radiography (DX), multidetector computed tomography (MDCT), high resolution flat panel CT (FPCT) and magnetic resonance imaging (MRI). The screws were scanned in vitro and after implantation in a fresh chicken tibia in order to simulate surrounding bone and soft tissue. The images were quantitatively evaluated with respect to the overall image quality and the extent and intensity of artifacts.ResultsIn all modalities, the artifacts generated by the magnesium screw had a lesser extent and were less severe as compared to the titanium screw (mean difference of artifact size of solo scanned screws in DX: 0.7 mm, MDCT: 6.2 mm, FPCT: 5.9 mm and MRI: 4.73 mm; p < 0.05). In MDCT and FPCT multiplanar reformations and 3D reconstructions were superior as compared with the titanium screw and the metal-bone interface after implanting the screws in chicken cadavers was more clearly depicted. While the artifacts of the titanium screw could be effectively reduced using metal-artifact reduction sequences in MRI (WARP, mean reduction of 2.5 mm, p < 0.05), there was no significant difference for the magnesium screw.ConclusionsMagnesium implants generate significantly less artifacts in common imaging modalities (DX, MDCT, FPCT and MRI) as compared with conventional titanium implants and therefore may facilitate post-operative follow-up.Electronic supplementary materialThe online version of this article (doi:10.1186/s12880-017-0187-7) contains supplementary material, which is available to authorized users.

Background Scaphoid fractures are the most common carpal fractures. They often need to be treated by surgery, where the use of a compression screw is the globally accepted gold standard. Surgeons may choose between different implant materials including titanium alloys, which remain in the body or are removed after healing. An alternative are biodegradable magnesium-based implants. Properties of magnesium alloys include high stability, osteoconductivity, potential reduction of infections and few artifacts in magnetic resonance imaging (MRI). The aim of this trial is to demonstrate non-inferiority of magnesium-based compression screws compared with titanium Herbert screws for scaphoid fractures. Methods The trial is designed as a multicenter, blinded observer, randomized controlled parallel two-group post market trial. Approximately 190 patients will be randomized (1:1) with stratification by center either to titanium or magnesium-based compression screws. Follow-up is 1 year per patient. Surgical procedures and aftercare will be performed according to the German treatment guideline for scaphoid fractures. The first primary endpoint is the patient-rated wrist evaluation (PRWE) score after 6 months. The second primary endpoint is a composite safety endpoint including bone union until 6 months, no adverse device effect (ADE) during surgery or wound healing and no serious ADE or reoperation within 1 year. The third primary endpoint is the difference in change MRI artifacts over time. Non-inferiority will be investigated for primary endpoints 1 (t-test confidence interval) and 2 (Wilson’s score interval) using both the full analysis set (FAS) and the per protocol population at the one-sided 2.5% test-level. Superiority of magnesium over titanium screws will be established using the FAS at the two-sided 5% test-level (Welch test) only if non-inferiority has been established for both primary endpoints. Secondary endpoints include quality of life. Discussion This study will inform care providers whether biodegradable magnesium-based implants are non-inferior to standard titanium Herbert screws for the treatment of scaphoid fractures in terms of wrist function and safety. Furthermore, superiority of magnesium-based implants may be demonstrated using MRI, which is used as surrogate endpoint for screw degradation. Trial registration DRKS, DRKS00013368 . Registered Dec 04, 2017. Electronic supplementary material The online version of this article (10.1186/s12891-019-2723-9) contains supplementary material, which is available to authorized users.

Introduction Acellular dermal matrices (ADMs) are now commonly used for breast reconstruction surgery. There are various products available: ADMs derived from human (HADM), porcine (PADM), or bovine (BADM) sources. Detailed long-term follow-up studies are necessary to detect differences in complication rates between these products. Material and Methods From 2010 to 2015, forty-one patients underwent 52 ADM-breast reconstructions in our clinic, including oncologic breast reconstructions and breast augmentation revisions (n = 52). 15x HADMs (Epiflex®/DIZG), 21x PADMs (Strattice®/LifeCell), and 16x BADMs (Tutomesh®/RTI Surgical) were implanted. Retrospective data collection with median follow-up of 36 months (range: 12–54 months) was performed. Results Overall complication rate was 17% after ADM implantation (HADM: 7%; PADM: 14%; BADM: 31%). In a composite endpoint of complications and Red Breast Syndrome, a lower event probability was observed between BADMs, PADMs, and HADMs (44%, 19%, and 7%, resp.; p = 0.01 for the trend). Furthermore, capsular contracture occurred in 6%, more frequently as compared to the current literature. Conclusions When ADM-based reconstruction is indicated, the authors suggest primarily the use of HADMs and secondary the use of PADMs. It is shown that BADMs have the highest complication probability within our patient cohort; nevertheless, BADMs convey physical advantages in terms of flexibility and better aesthetic outcomes. The indication for the use of ADMs should be filled for each case individually.

Background The interest in youthful appearance and rejuvenating procedures is unbroken in our society. Besides surgical procedures, permanent fillers are utilized. The incorrect and unprofessional use of these substances, auto-injections in particular, have devastating results for patients and are challenging for the plastic surgeon. The aim of this retrospective study was to delineate the differences between permanent and non-permanent filler complications and appropriate treatment options. Methods We conducted a retrospective study and researched the hospital information system in the time period from 2001 to 2020. Patients with unprofessional use of permanent fillers, auto-injections and injections of unformulated substances were determined. Age, gender, localization, complications, length of hospital stay, comorbidities, histopathological workups and surgical salvage procedures were noted. Descriptive statistics were calculated. Results Seventeen patients were identified from 2001 till 2020. In four cases, auto-injections by the patients were the cause, whereas in the other patients the injections were performed by medical staff. Ages range from 18 to 57 years. Fourteen patients were female and three were male. The injected substances could be recognized as synthol, silicone, vaseline, fat tissue, hyaluronic acid as well as non-medical substances. Surgical procedures were necessary in eleven cases. One patient died because of the underlying diseases. Conclusion Our results indicate different sequels of filler materials injected in an unprofessional way, possible complications, conservative and surgical techniques to resolve these rare complications. We suggest a staged therapy adjusted to the clinical symptoms. Milder symptoms can be handled conservatively, whereas severe infections, skin breakdowns or persistent granuloma are justifying indications for surgical treatment. Level of Evidence V This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Autologous fat grafting represents an attractive source for tissue engineering applications in the field of reconstructive medicine. However, in adipogenic differentiation protocols for human adiposederived stem cells, the concentration of glucose and insulin varies considerably. With the intent to gain maximum tissue augmentation, we focused on the late phase of adipogenesis. In this study, we modified the differentiation protocol for adipose-derived stem cells by prolongation of the induction period and the application highly concentrated glucose and insulin. Human adipose-derived stem cells were isolated from subcutaneous depots and differentiated in a standard induction medium for the first two weeks, followed by two weeks with varying glucose and insulin concentrations. Morphological changes assessed using Oil-RedO staining were examined for corresponding alterations in the expression of the adipogenic markers peroxisome proliferator-activated receptor gamma (PPARγ) and lipoprotein lipase (LPL). Furthermore, glucose and lactate levels in conditioned media were monitored over the period of differentiation. We found high-glucose media increasing the level of lipid accumulation and the size of single droplets whereas insulin significantly showed a dosedependent negative effect on fat storage. However, whereas high glucose stimulated PPARγ transcription, expression levels in insulin-treated cells remained constant. Results permit assumptions that a high-glucose medium intensifies the degree of differentiation in mature adipocytes providing conditions to promote graft volume while we have identified highly concentrated insulin treatment as an inhibitor of lipid storage in the late adipogenic differentiation.