Mapping wrist motion: 3D CT analysis after scapholunate ligament transection.

The injury of the scapholunate (SL) ligament is common in wrist traumas leading to pain and reduced wrist function. The wrist's unique joint design and possible underlying theories as the carpal row theory were subject to earlier investigations studying wrist kinematics. Nevertheless, a comprehensive understanding of how SL ligament injuries affect wrist biomechanics is still lacking. Through a quantitative analysis of carpal bone motion patterns, we evaluated the impact on wrist kinematics occurring after SL ligament injury. We conducted a study using computer tomography imaging to analyse wrist kinematics after SL ligament transection in 21 fresh-frozen anatomical specimens. The collected data were then transformed into 3D models, employing both standardized global and object coordinate systems. The study encompassed the evaluation of rotation and translation for each individual carpal bone, as well as the ulna, and all metacarpal bones in reference to the radius. The study showed a significant increase in rotation towards palmar (p < 0.01), particularly notable for the scaphoid, following transection of the SL ligament during palmar flexion. Ulnar deviation did not significantly affect rotation or translation, and radial deviation also showed no significant changes in rotation or translation. The study highlights the significance of the SL ligament in wrist kinematics, revealing that SL ligament tears lead to changes in wrist motion. While we observed significant rotational changes for the scaphoid, other carpal bones showed less pronounced alterations, emphasizing the complexity of wrist biomechanics.

Quick and safe: why a k-wire-extension-block-fixation of a bony mallet finger is the favoured treatment.

INTRODUCTION: Mallet fingers are the most common tendon injuries of the hand. Bony avulsion distal finger extensor tendon ruptures causing a mallet finger require special attention and management. In this monocentral study, we analyzed the clinical and individual outcomes succeeding minimal invasive k-wire extension block treatment of bony mallet fingers. MATERIALS AND METHODS: In a retrospective study, we sent a self-designed template and a QUICK-DASH score questionnaire to all patients, who were treated because of a bony mallet finger between 2009 and 2022 and fulfilled the inclusion criteria. A total of 244 requests were sent out. 72 (29.5%) patients participated in the study. Forty-five men and twenty-seven women were included. RESULTS: 98.7% (n = 75) of the cases were successfully treated. Patients were highly satisfied with the treatment (median 8.0; SD ± 2.9; range 1.0-10.0). Based on the QUICK-DASH score, all patients showed no difficulties in daily life. The extent of avulsion did not influence the outcome. CONCLUSION: We conclude that the minimally invasive treatment of a bony mallet finger should be offered to every patient, because it is safe, fast, and reliable. Thus, we propose to perform extension-block pinning independently of the articular area.

Secretome of Adipose-Derived Stem Cells Cultured in Platelet Lysate Improves Migration and Viability of Keratinocytes.

Chronic wounds depict a silent epidemic challenging medical professionals worldwide. Regenerative medicine uses adipose-derived stem cells (ADSC) in promising new therapies. In this study, platelet lysate (PL) as a xenogen-free substitute for foetal bovine serum (FBS) in ADSC culture was used to create an ADSC secretome containing cytokines for optimal wound healing conditions. The ADSC secretome was tested on keratinocytes for migrational behaviour and viability. Therefore, human ADSC were characterized under FBS (10%) and PL (5% and 10%) substitution, regarding morphology, differentiation, viability, gene and protein expression. ADSC were then cultured in 5% PL and their secretome was used for stimulation of keratinocyte migration and viability. To enhance the effect, ADSC were treated with Epithelial Growth Factor (EGF, 100 ng/mL) and hypoxia (1% O2). In both PL and FBS groups, ADSC expressed typical stem cell markers. PL induced a significantly higher increase in cell viability compared to FBS substitution. ADSC secretome contained various beneficial proteins which enhance the wound healing capacity of keratinocytes. This could be optimized treating ADSC with hypoxia and EGF. In conclusion, the study shows that ADSC cultivated in 5% PL can effectively support wound healing conditions and can be considered as a promising new therapy for individual treatment of chronic wound disorders.

Prospective analysis of grip strength and load distribution after surgical treatment of common diseases of the hand with novel's manugraphy® system.

BACKGROUND: Carpal tunnel syndrome, A1 annular pulley stenosis and Dupuytren's contracture are among the most common conditions of the hand. In this study, we investigated the impact of surgical procedure on hand grip strength and high-resolution spatial load distribution in individuals suffering from those diseases over a follow-up period of one year. MATERIALS AND METHODS: In this prospective study, data of 9 patients with carpal tunnel syndrome, 12 patients with A1 annular pulley stenosis and 7 patients with Dupuytren's contracture were evaluated. Only patients with unilateral disease were included providing the contralateral hand as an intra-individual control. Grip strength was measured with cylindrical instruments in two different sizes with respect to the hand size of the patients. Maximum and average values of grip strength as well as spatial load distribution in each finger, thenar, hypothenar and palm were analyzed. Data of the affected patients were collected preoperatively and 6 weeks, 6 months and 1 year postoperatively. Grip strength and spatial load distribution were compared preoperatively to postoperatively. In addition, DASH score, Levine score, 2-point discrimination and degree of flexion contracture were assessed. RESULTS: The patients with A1 annular pulley stenosis showed a significant increase in grip strength 6 months and one year postoperatively. Patients with carpal tunnel syndrome and Dupuytren's contracture showed no significant difference in grip strength over the course of time. An increase in the percentual grip strength of the thenar in patients with carpal tunnel disease and within the affected finger in A1 annular pulley stenosis was observed over the course of time. The DASH score was significantly lower in all patient cohorts one year postoperatively. CONCLUSION: Surgical procedure in carpal tunnel syndrome, A1 annular ligament stenosis and Dupuytren's contracture improves the functionality of the hand in everyday life. Some areas of the hand seem to compensate other weaker areas in grip strength.

Specific features of ex-obese patients significantly influence the functional cell properties of adipose-derived stromal cells.

Adipose-derived stromal cells (ADSC) are increasingly used in clinical applications due to their regenerative capabilities. However, ADSC therapies show variable results. This study analysed the effects of specific factors of ex-obese patients on ADSC functions. ADSC were harvested from abdominal tissues (N = 20) after massive weight loss. Patients were grouped according to age, sex, current and maximum body mass index (BMI), BMI difference, weight loss method, smoking and infection at the surgical site. ADSC surface markers, viability, migration, transmigration, sprouting, differentiation potential, cytokine secretion, telomere length and mtDNA copy number were analysed. All ADSC expressed CD73, CD90, CD105, while functional properties differed significantly among patients. A high BMI difference due to massive weight loss was negatively correlated with ADSC proliferation, migration and transmigration, while age, sex or weight loss method had a smaller effect. ADSC from female and younger donors and individuals after weight loss by increase of exercise and diet change had a higher activity. Telomere length, mtDNA copy number, differentiation potential and the secretome did not correlate with patient factors or cell function. Therefore, we suggest that factors such as age, sex, increase of exercise and especially weight loss should be considered for patient selection and planning of regenerative therapies.

Vessel grafts for tissue engineering revisited-Vessel segments show location-specific vascularization patterns in ex vivo ring assay.

OBJECTIVE: Transplantation of prefabricated tissue-engineered flaps can be a potential alternative for healing large tissue defects. Providing adequate vascular supply for an engineered tissue construct is one of the key points in establishing successful tissue engineering-based treatment approaches. In tissue engineering-based vascularization techniques like the arteriovenous loop, vascular grafts with high angiogenic potential can help to enhance neovascularization and tissue formation. Therefore, our study aimed to compare the angiogenic potential of vascular grafts from different locations in the rat. METHODS: The angiogenic activity was investigated by an ex vivo vessel outgrowth ring assay using 1-mm height vascular segments embedded in fibrin for 2 weeks. RESULTS: Maximum vessel outgrowth was observed on Days 10-12. Upper extremity vessels exhibited stronger outgrowth than lower extremity vessels. Moreover, arterial vessels demonstrated higher angiogenic potential compared with venous vessels. CONCLUSION: Collectively, our ex vivo findings suggest that upper extremity arterial vessels have a higher angiogenic capacity, which could be used to improve neovascularization and tissue formation in tissue engineering.

Recombinant Spider Silk Bioinks for Continuous Protein Release by Encapsulated Producer Cells.

Targeted therapies using biopharmaceuticals are of growing clinical importance in disease treatment. Currently, there are several limitations of protein-based therapeutics (biologicals), including suboptimal biodistribution, lack of stability, and systemic side effects. A promising approach to overcoming these limitations could be a therapeutic cell-loaded 3D construct consisting of a suitable matrix component that harbors producer cells continuously secreting the biological of interest. Here, the recombinant spider silk proteins eADF4(C16), eADF4(C16)-RGD, and eADF4(C16)-RGE have been processed together with HEK293 producer cells stably secreting the highly traceable reporter biological TNFR2-Fc-GpL, a fusion protein consisting of the extracellular domain of TNFR2, the Fc domain of human IgG1, and the luciferase of Gaussia princeps as a reporter domain. eADF4(C16) and eADF4(C16)-RGD hydrogels provide structural and mechanical support, promote HEK293 cell growth, and allow fusion protein production by the latter. Bioink-captured HEK293 producer cells continuously release functional TNFR2-Fc-GpL over 14 days. Thus, the combination of biocompatible, printable spider silk bioinks with drug-producing cells is promising for generating implantable 3D constructs for continuous targeted therapy.

Bilateral free flap breast reconstruction using venous cross-over bypass to contralateral internal mammary artery for salvaging thrombosed arterial anastomosis in unilateral repeated irradiation of the breast: A case report.

Adjuvant radiotherapy in breast cancer patients might enhance complications after autologous breast reconstruction, including thrombosis of the internal mammary artery (IMA) precluding its use as recipient vessel. This case report shows a salvage procedure for thrombosis of the IMA during bilateral autologous breast reconstruction in a 51-year-old patient who had undergone repeated irradiation of the chest wall after Hodgkin's disease and recurrent breast carcinoma of the right side. After mastectomy of the right breast and prophylactic mastectomy of the left breast, the patient desired breast reconstruction with autologous tissue. During simultaneous bilateral breast reconstruction using two deep inferior epigastric perforator (DIEP) flaps anastomosed to the left and right inframammary vessels, arterial anastomosis to the right IMA was not feasible due to arterial thrombosis. A salvage procedure using an interpositional cephalic vein graft as a crossover bypass and a subcutaneous presternal tunnel was used. The inferior epigastric artery of the right DIEP flap was anastomosed to the venous bypass, which was anastomosed to the contralateral IMA. Both flaps healed without any complications during the postoperative course and follow up of 6 months. The presented case shows the feasibility of a cross-over venous bypass procedure during bilateral breast reconstruction as salvage maneuver for the arterial anastomosis after repeated radiation of the unilateral breast.

Human adipose-derived stem cells support lymphangiogenesis in vitro by secretion of lymphangiogenic factors.

Lymphedema is a chronic progressive disease ultimately resulting in severe, disfiguring swelling and permanent changes of the affected tissues. Presently, there is no causal treatment approach of lymphedema. Therefore, most therapies are purely symptomatic. However, the recent use of stem cell-based therapies has offered new prospects for alternative treatment options. The present study was performed to investigate the effects of human adipose-derived stem cells (ADSCs) on human dermal lymphatic endothelial cells (HDLECs) in terms of basic in vitro lymphangiogenic assays (WST-8 assay, scratch assay, transmigration assay, sprouting assay, tube formation assay). The influence of ADSC-conditioned medium (ADSC-CM) on HDLECs was compared to recombinant VEGF-C, bFGF and HGF. Further ADSC-CM was characterized by protein microarray and enzyme-linked immunosorbent assay (ELISA). Although key-lymphangiogenic growth factors - like VEGF-C - could only be detected in low concentrations within the conditioned medium (CM), HDLECs were potently stimulated to proliferate, migrate and to form tube like structures by ADSC-CM. Despite concentrations more than hundredfold higher than those found in the conditioned medium, stimulation with recombinant VEGF-C, bFGF and HGF was still weaker compared to ADSC-CM. These results highlight the effectiveness of growth factors secreted by ADSC to stimulate HDLEC, potentially providing a promising new therapeutic approach for the treatment of lymphedema.

Donor Site Morbidity of Patients Receiving Vertical Rectus Abdominis Myocutaneous Flap for Perineal, Vaginal or Inguinal Reconstruction.

BACKGROUND: Management of donor site closure after harvesting a vertical rectus abdominis myocutaneous (VRAM) flap is discussed heterogeneously in the literature. We aim to analyze the postoperative complications of the donor site depending on the closure technique. METHODS: During a 12-year period (2003-2015), 192 patients in our department received transpelvic VRAM flap reconstruction. Prospectively collected data were analyzed retrospectively. RESULTS: 182 patients received a VRAM flap reconstruction for malignant, 10 patients for benign disease. The median age of patients was 62 years. 117 patients (61%) received a reconstruction of donor site by Vypro® mesh, 46 patients (24%) by Vicryl® mesh, 23 patients (12%) by direct closure and 6 patients (3%) by combination of different meshes. 32 patients (17%) developed in total 34 postoperative complications at the donor site. 22 complications (11%) were treated conservatively, 12 (6%) surgically. 17 patients (9%) developed incisional hernia during follow-up, with highest incidence in the Vicryl® group (n = 8; 17%) and lowest in the Vypro® group (n = 7; 6%). Postoperative parastomal hernias were found in 30 patients (16%) including three patients with simultaneous hernia around an urostomy and a colostomy. The highest incidence of parastomal hernia was found in patients receiving primary closure of the donor site (n = 6; 26%), the lowest incidence in the Vypro® group (n = 16; 14%). CONCLUSION: The use of Vypro® mesh for donor site closure appears to be associated with a low postoperative incidence of complications and can therefore be recommended as a preferred technique.

Bone Allograft and Locking Plate for Severe Proximal Humeral Fractures: Early and Late Outcomes.

BACKGROUND Early failure of osteosyntheses is common even with use of locking plates. In patients with comminuted fractures and epiphyseal osseous defects, we performed a series of osteosyntheses by locking plate in combination with an allograft bone augmentation. Because of encouraging short-term results in the literature, we assumed that the method could be a potential alternative to a reverse shoulder prosthesis. MATERIAL AND METHODS Twenty-six patients with a dislocated proximal humeral fracture (Neer IV/V/VI) were studied. A lyophilized allogeneic bone graft was used to reinforce the humeral head fragments before locking plate osteosynthesis. The outcomes of fractures were assessed with Disabilities of the Arm, Shoulder and Hand (DASH) and Constant-Murley (Constant) scores, range of motion, a visual analog scale, and with radiological testing. The Constant-Murley scores were the endpoint of our study. RESULTS The Neer classification of the fractures was type IV in 4 patients, type V in 20 patients, and type VI in 2 patients. The mean DASH score was 52.85 (range, 4.17-79.3) and the mean Constant score was 39.26 (range, 17-88). We observed late necrosis of the humeral head in 15 of 24 patients (62.5%), although early radiological follow-up showed that the humeral head had been anatomically reconstructed. CONCLUSIONS Long-term follow-up demonstrated inferior functional results, as displayed by poor Constant scores. There was a high incidence of necrosis, in spite of initial anatomical reconstruction. Biointegration of the allogeneic bone graft and revascularization of the humeral head fragments could be impaired in geriatric patients who have gross dislocation. Therefore, augmentation of the humeral head with allogeneic bone grafts cannot be recommended in these patients.

External Screw-Threaded Traction Device Helps Optimize Finger Joint Mobility in Severe Stage III and IV Dupuytren Disease.

BACKGROUND Treating advanced finger joint contractures from Dupuytren disease remains a challenge. We evaluated the effectiveness of a skeletal distraction device versus alternative treatment options. MATERIAL AND METHODS We analyzed the surgical treatment of contracted finger joints in stage III and stage IV Dupuytren's disease over a 10-year period. Data were obtained from inpatient and outpatient medical records, including postoperative clinical examinations and extended Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire scores. Complications of infection, postoperative pain, and wound healing disorders were recorded. RESULTS A total of 79 patients (83 hands) were assigned to 2 treatment groups. Patients in group 1 underwent an initial open transection of the main fibrous cord, Z-plasty, distraction with the Erlangen external distraction device, and fasciectomy. The distraction period was 13 to 81 days (mean 31 days). Group 2 underwent a conventional single-stage fasciectomy and arthrolysis. DASH scores and subjective patient satisfaction were lower in group 1 (20.7/33%) than in group 2 (10.3/50%). However, the staged approach of group 1 to treat proximal interphalangeal joint contractures in the long term (improvement >40%) was more effective than the approach of group 2 (>33%). Distraction device pin infections occurred in 20% of hands. Postoperative pain and complex regional pain syndrome type I occurred in 25% of hands in group 1 and 3% in group 2. CONCLUSIONS A screw thread driven external fixation device is useful in end-stage Dupuytren's finger joint contractures. It is indicated when joint contractures are advanced and simple arthrolysis is insufficient.

Abdominal Panniculectomy Can Simplify Kidney Transplantation in Obese Patients.

BACKGROUND: Obesity is frequently present in patients suffering from end-stage renal disease (ESRD). However, overweight kidney transplant candidates are a challenge for the transplant surgeon. Obese patients tend to develop a large abdominal panniculus after weight loss creating an area predisposed to wound-healing disorders. Due to concerns about graft survival and postoperative complications after kidney transplantation, obese patients are often refused in this selective patient cohort. The study aimed to analyze the effect of panniculectomies on postoperative complications and transplant candidacy in an interdisciplinary setting. METHODS: A retrospective database review of 10 cases of abdominal panniculectomies performed in patients with ESRD prior to kidney transplantation was conducted. RESULTS: The median body mass index was 35.2 kg/m2 (range 28.5-53.0 kg/m2) at first transplant-assessment versus 31.0 kg/m2 (range 28.0-34.4 kg/m2) at panniculectomy, and 31.6 kg/m2 (range 30.3-32.4 kg/m2) at kidney transplantation. We observed no major postoperative complications following panniculectomy and minor wound-healing complications in 2 patients. All aside from 1 patient became active transplant candidates 6 weeks after panniculectomy. No posttransplant wound complications occurred in the transplanted patients. CONCLUSION: Abdominal panniculectomy is feasible in patients suffering ESRD with no major postoperative complications, thus converting previously ineligible patients into kidney transplant candidates. An interdisciplinary approach is advisable in this selective patient cohort.

Macromastia: an economic burden? A disease cost analysis based on real-world data in Germany.

PURPOSE: Symptomatic macromastia causes physical and psychological problems that can lead to restrictions in the patients' social and working lives and a reduced quality of life. Associated medical treatments also have a considerable impact on health-care costs. Several studies have assessed these costs, but the total disease costs of macromastia have never been evaluated on the basis of real-world data. METHODS: The data for 76 patients who underwent reduction mammoplasty between 2008 and 2016 were collected using a two-part questionnaire (preoperative and postoperative), as well as the patient files. Topics surveyed, besides demographic data, included physician visits, medical imaging, medical procedures, medical treatments, rehabilitation and convalescent measures, drug intake, medical aids, exercise activity, and sick leave days before surgery, to calculate the costs per year of conservative treatment of symptomatic macromastia. RESULTS: The mean time from start of symptoms to surgery was 11.82 years. The data for this group of patients with symptomatic macromastia show that costs per patient amount to €1677.55 per year. These costs include medical consultation, radiological imaging, medical treatments and procedures, physical therapy and rehabilitation, medication, special brassieres, exercise classes costs for sick leave due to problems with macromastia, and travel expenses. CONCLUSIONS: These results show that considerable health-care costs arise due to macromastia with conservative treatment. Overall, macromastia costs €1677.55 per patient/year. In particular, lost productivity due to sick days and the costs of physiotherapy are factors driving the high costs.

The influence of K-wire transfixation on proximalization of the first metacarpal after resection suspension interposition arthroplasty.

INTRODUCTION: Osteoarthritis of the first carpometacarpal joint is a common degenerative disease and surgical treatment includes resection suspension interposition arthroplasty (RSIA) with or without temporary transfixation of the first metacarpal. One major drawback includes proximalization of the first metacarpal during the postoperative course. Specific data comparing different transfixation techniques in this context is sparse. MATERIALS AND METHODS: In this retrospective study, we measured the trapezial space ratio (TSR) in 53 hands before and after RSIA to determine the proximalization of the first metacarpal depending on the type of Kirschner (K)-wire transfixation. We, therefore, compared transfixation of the first metacarpal to the scaphoid with one K-wire (1K) to transfixation of the first metacarpal with two K-wires (2K), either to the carpus (2Ka), or to the second metacarpal (2Kb), or to both second metacarpal and carpus (2Kc). RESULTS: While preoperative TSR did not differ between group 1K and 2K (p = 0.507), postoperative TSR was significantly higher in group 2K compared to 1K (p = 0.003). Comparing subgroups, postoperative TSR was significantly higher in group 2Kc than 1K (p = 0.046), while we found no significant difference comparing either group 2Ka or 2Kb to 1K (p = 0.098; p = 0.159). Neither did we find a significant difference within 2K subgroups, comparing group 2Ka and 2Kb (p = 0.834), 2Ka and 2Kc (p = 0.615), or 2Kb and 2Kc (p = 0.555). CONCLUSIONS: The results of our study suggest that transfixation with two K-wires should be preferred to transfixation with one K-wire after RSIA. Specifically, transfixation from first to second metacarpal and from first metacarpal to carpus resulted in least proximalization of the first metacarpal postoperatively.

Retrospective analysis of free temporoparietal fascial flap for defect reconstruction of the hand and the distal upper extremity.

INTRODUCTION: Soft tissue reconstruction of the hand and distal upper extremity is challenging to preserve the function of the hand as good as possible. Therefore, a thin flap has been shown to be useful. In this retrospective study, we aimed to show the use of the free temporoparietal fascial flap in soft tissue reconstruction of the hand and distal upper extremity. METHODS: We analysed the outcome of free temporoparietal fascial flaps that were used between the years 2007and 2016 at our institution. Major and minor complications, defect location and donor site morbidity were the main fields of interest. RESULTS: 14 patients received a free temporoparietal fascial flap for soft tissue reconstruction of the distal upper extremity. Minor complications were noted in three patients and major complications in two patients. Total flap necrosis occurred in one patient. CONCLUSION: The free temporoparietal fascial flap is a useful tool in reconstructive surgery of the hand and the distal upper extremity with a low donor site morbidity and moderate rates of major and minor complications.

Polytetrafluoroethylene (PTFE) suture vs fiberwire and polypropylene in flexor tendon repair.

BACKGROUND: In this study, we evaluate the value of novel suture material based on monofilamentous-extruded polyfluoroethylene (PTFE) compared to polypropylene (PPL) and Fiberwire (FW). MATERIALS AND METHODS: 60 flexor tendons were harvested from fresh cadaveric upper extremities. 4-0 sutures strands were used in the PPL, FW and PTFE group. Knotting properties and mechanical characteristics of the suture materials were evaluated. A 4-strand locked cruciate (Adelaide) or a 6-strand (M-Tang) suture technique was applied as core sutures for a tendon repair. Two-way ANOVA tests were performed with the Bonferroni correction. RESULTS: Stable knotting was achieved with 5 throws with the PPL material, 7 throws for FW and 9 throws for PTFE. In the PPL group, linear tensile strength was 45.92 ± 12.53 N, in the FW group 80.11 ± 18.34 N and in the PTFE group 76.16 ± 29.10 N. FW and PTFE are significantly stronger than PPL but show no significant difference among each other. Similar results were obtained in the subgroup comparisons for different repair techniques. The Adelaide and the M-Tang knotting technique showed no significant difference. CONCLUSION: Fiberwire showed superior handling and knotting properties in comparison to PTFE. However, PTFE allows easier approximation of the stumps. In both, M-Tang and Adelaide repairs, PTFE was equal to FW in terms of repair strength. Both PTFE and FW provide for a robust tendon repair so that early active motion regimens for rehabilitation can be applied.

Novel imaging methods reveal positive impact of topical negative pressure application on tissue perfusion in an in vivo skin model.

The influence of topical negative pressure application (TNPA) on tissue perfusion still remains controversial. TNPA was applied for 30 minutes on intact skin of 21 healthy participants. Measurements of tissue oxygen saturation and tissue temperature as signs of tissue perfusion were performed before application of the TNPA, directly after removal of the TNPA and 5, 10, 15, 20, and 30 minutes after removal of the dressing using the near infrared imaging (NIRI) and a thermal imaging camera. Tissue oxygen saturation showed an increase from 67.7% before applying the TNPA to 76.1% directly after removal of TNPA, followed by a decrease of oxygen saturation 30 minutes after removal of TNPA. The measured temperature of the treated skin area increased from 32.1°C to 36.1°C after removal of TNPA with a consecutive decrease of the temperature 30 minutes after removal. TNPA resulted in both a higher tissue oxygen saturation and a higher skin temperature after 30 minutes compared to the beginning. TNPA increases both tissue oxygen saturation and skin temperature as sign of an increase of tissue perfusion. NIRI and thermal imaging proved to be useful for measuring changes in tissue perfusion.

Bone tissue engineering using adipose-derived stem cells and endothelial cells: Effects of the cell ratio.

The microvascular endothelial network is essential for bone formation and regeneration. In this context, endothelial cells not only support vascularization but also influence bone physiology via cell contact-dependent mechanisms. In order to improve vascularization and osteogenesis in tissue engineering applications, several strategies have been developed. One promising approach is the coapplication of endothelial and adipose derived stem cells (ADSCs). In this study, we aimed at investigating the best ratio of human umbilical vein endothelial cells (HUVECs) and osteogenic differentiated ADSCs with regard to proliferation, apoptosis, osteogenesis and angiogenesis. For this purpose, cocultures of ADSCs and HUVECs with ratios of 25%:75%, 50%:50% and 75%:25% were performed. We were able to prove that cocultivation supports proliferation whereas apoptosis was unidirectional decreased in cocultured HUVECs mediated by a p-BAD-dependent mechanism. Moreover, coculturing ADSCs and HUVECs stimulated matrix mineralization and the activity of alkaline phosphatase (ALP). Increased gene expression of the proangiogenic markers eNOS, Flt, Ang2 and MMP3 as well as sprouting phenomena in matrigel assays proved the angiogenic potential of the coculture. In summary, coculturing ADSCs and HUVECs stimulates proliferation, cell survival, osteogenesis and angiogenesis particularly in the 50%:50% coculture.

Secondary "Hybrid Reconstruction" Concept with Silicone Implants After Autologous Breast Reconstruction - Is It Safe and Reasonable?

BACKGROUND The use of autologous tissue for breast reconstructive surgery following mastectomy has become routine and allows for excellent symmetry and aesthetic results. However, in some cases, the amount of tissue available from the utilized flaps is not enough to achieve the desired outcome. The use of autologous fat grafting, as well as other techniques, has been described to deal with such problems. However, though well-established, these techniques may also fail to achieve the desired results. The aim of this study was to highlight the opportunity to improve aesthetic results using a secondary prosthesis underneath the previously used free flap and to examine whether this is a safe and reasonable procedure. MATERIAL AND METHODS In our study we included patients with unsatisfied aesthetic results after free flap procedures (DIEP, S-GAP, TMG, and FCI) between 2011 and 2018. In each case described, a secondary prosthesis was placed underneath the original flap in order to improve symmetry, shape and projection. Patient age, indication for surgery, adjuvant therapy, complications and outcomes have been registered. A 12-point scale was established to analyze patient satisfaction and aesthetic outcome. RESULTS Overall "operative success" was achieved in all 13 patients (14 flaps) evaluated. At 12 months after reconstruction, all aesthetic scores collected were between good and excellent. In contrast to other studies, we chose a secondary approach for the flap augmentation and we used the epipectoral pocket for the placement of the implant. In our series, low rates of early and late post-operative complications were observed, with a high overall rate of satisfaction. CONCLUSIONS The demonstrated "Hybrid Breast Reconstruction" approach, using an implant underneath a free flap autologous breast reconstruction, provided a safe and reliable option to optimize breast reconstruction outcomes.