Surgery improves the clinical and radiological outcome in Rockwood type IV dislocations, whereas Rockwood type III dislocations benefit from conservative treatment.

PURPOSE: Despite the available classifications, diagnostics and treatment of acute acromioclavicular joint (ACJ) injuries are still vague and challenging for trauma and shoulder surgeons. This study aimed to evaluate the dynamic radiographic as well as clinical outcome of operatively and conservatively treated Rockwood (RW) type III and IV ACJ dislocations. MATERIALS AND METHODS: All patients with RW type III and IV ACJ dislocations between 2009 and 2016 (n = 226) were included in this retrospective data analysis with a prospective follow-up examination. According to their injury classification, patients were subdivided in an operative and conservative treatment group. Examiner blinded clinical evaluation including the constant score (CS), American shoulder and elbow surgery (ASES) score, the acromioclavicular joint instability (ACJI) score, visual analog scale (VAS), bilateral force measurements, and posttraumatic/postsurgical sequelae were assessed. Fluoroscopic evaluations including dynamic stability assessment with functional axillary views were performed for every patient. RESULTS: For follow-up examination (mean 4.8 years ± 0.3 SEM) 56 patients (29 RW type III, 27 RW type IV) were available. In patients with RW type III ACJ dislocations [operative (n = 10); conservative (n = 19)] prolonged duration of treatment was seen in operatively treated patients (p < 0.05). Clear improvement could be shown for the ACJI score (p < 0.05) and coracoclavicular (CC) and acromioclavicular (AC) distance (p < 0.05) in the operative group. In patients with RW type IV ACJ dislocations [operative (n = 18); conservative (n = 9)] superior clinical results were found in operated patients with highly significant differences for the ACJI score (p < 0.001). Radiographic dynamic horizontal analysis showed nearly normalized anteroposterior translation in operated patients (p < 0.05). No differences were found regarding arthroscopic or open procedures. CONCLUSION: Accurate diagnostics including sufficient dynamic stability assessment with functional axillary views are strongly advised for patients with ACJ dislocations. Conservative treatment should be recommended for patients with RW type III ACJ dislocations, due to shorter duration of treatment with good clinical results but lacking operative risks. In patients with RW type IV ACJ dislocations, surgical treatment is recommended because of superior clinical and radiological results. LEVEL OF EVIDENCE: Level III.

Fibrin-based delivery strategies for acute and chronic wound healing.

Fibrin, a natural hydrogel, is the end product of the physiological blood coagulation cascade and naturally involved in wound healing. Beyond its role in hemostasis, it acts as a local reservoir for growth factors and as a provisional matrix for invading cells that drive the regenerative process. Its unique intrinsic features do not only promote wound healing directly via modulation of cell behavior but it can also be fine-tuned to evolve into a delivery system for sustained release of therapeutic biomolecules, cells and gene vectors. To further augment tissue regeneration potential, current strategies exploit and modify the chemical and physical characteristics of fibrin to employ combined incorporation of several factors and their timed release. In this work we show advanced therapeutic approaches employing fibrin matrices in wound healing and cover the many possibilities fibrin offers to the field of regenerative medicine.

Long-term outcome following upper extremity replantation after major traumatic amputation.

BACKGROUND: Amputations in general and amputations of upper extremities, in particular, have a major impact on patients' lives. There are only a few long-term follow-up reports of patients after macro-replantation. We present our findings in contrast with the existing literature. METHODS: Sixteen patients with traumatic macro-amputation of an upper extremity were eligible for inclusion in this study. Altogether, the patients underwent replantation in 3 institutions between 1983 and 2011. RESULTS: Twelve male and four female patients with an average age at injury of 40.6 years (range, 14-61 years) were included in this study. The mean follow-up period was 13.5 years (range, 4.4-32.6 years; SD, 5.7 years). The mean disabilities of the arm, shoulder and hand (DASH) outcome measure was 41 (range, 5.2-94.8; SD, 18.2), functional independence measurement (FIM) was 125 (range, 120-126; SD, 1.8). Chen I representing very good function was accounted in six, Chen II representing good function in eight, Chen III (fair) in one and Chen IV (bad function) in one patient. CONCLUSIONS: We found that while the majority of the included patients exhibited good or very good function of the extremity, none of the replanted appendages regained normal levels of functionality. In addition, all participants were very satisfied with their outcomes. Positive long-term results with high rates of subjective satisfaction are possible after replantation of upper extremities.

Pre-clinical evaluation of liposomal gene transfer to improve dermal and epidermal regeneration.

Liposomal gene transfer effectively enhances dermal and epidermal regeneration in burned rodents. To advance this treatment to clinical studies, we investigated the efficacy of liposomal gene transfer in a clinically relevant porcine wound model. Mimicking the clinical scenario, six female Yorkshire pigs (40-50 kg) received up to 12 burns of 50 cm(2) area that were fully excised and covered with skin autograft meshed at 4:1 ratio 24 h post-burn. Animals received control injections (empty liposomes), liposomes (DMRIE-C) containing 1 mg LacZ-cDNA, or liposomes (DMRIE-C) with 1 mg of platelet-derived growth factor (PDGF)-cDNA, or the naked PDGF gene. Serial biopsies were taken from different wound sites at multiple time points up to 12 days post-wounding. Transfection efficacy and transfection rate of LacZ and localization of beta-gal were determined by immunohistochemical and immunofluorescent techniques. RT-PCR and multiplex protein analysis (ELISA) were used to measure levels of growth factor mRNA transcribed and growth factor protein translated. Wound re-epithelialization and graft adhesion was evaluated using planimetric analysis and clinical scores. We found that peak transfection of liposomal beta-galactosidase occurred on day 2, with a fluorescence increase of 154% to baseline (P<0.001). Transfection intensity dropped to 115% above baseline on day 4 (P<0.001) and 109% on day 7. Immunohistochemistry showed a maximum transfection rate of 34% of cells in wound tissue. Gene transfer of liposomal PDGF-cDNA resulted in increased PDGF-mRNA and protein expression on days 2 and 4, and accelerated wound re-epithlialization as well as graft adhesion on day 9 (P<0.05). In this study, we showed that liposomal cDNA gene transfer is possible in a porcine wound model, and by using PDGF-cDNA we further showed that dermal and epidermal regeneration can be improved. These data indicate that liposomal gene transfer can be a new therapeutic approach to improve wound healing in humans.

Cyanoacrylate tissue sealant impairs tissue integration of macroporous mesh in experimental hernia repair.

BACKGROUND: Tissue sealants have been proposed as an alternative to permanent fixation devices in hernia repair with the aim of reducing perforation-associated complications and chronic pain. Sealants can be divided into three main categories: synthetic glues (e.g., cyanoacrylate based), biologic products (e.g., fibrin sealant), and genetically engineered polymer protein glues. The beneficial effects of fibrin sealant have been reported in both experimental and clinical hernia repair. However, data on cyanoacrylate glues for mesh sealing are limited. METHODS: In 20 Sprague-Dawley rats, two hernia defects (1.5 cm in diameter) per animal were created bilaterally in the midline of the abdominal wall. The peritoneum was spared. The lesions were left untreated for 10 days to achieve a chronic condition. Defects then were covered with TI-Mesh xl (2 x 2 cm), which was glued with Glubran-II. The time points of sacrifice were 17 days, 28 days, and 3 months. At autopsy, meshes were biomechanically tested, and histology was performed. RESULTS: Tissue integration of the meshes was impaired at all time points by impenetrable glue plaques. At application sites, the elasticity of the abdominal wall was significantly reduced because of nonresorbed, rigid glue residues. CONCLUSIONS: Mesh fixation by Glubran-II impairs tissue integration, elicits inflammation, and unfavorably alters the biomechanics of macroporous mesh and the abdominal wall.

Adverse effects of porcine small intestine submucosa implants in experimental ventral hernia repair.

BACKGROUND: Biomeshes made of porcine small intestine submucosa (SIS) have recently been suggested for repair of ventral hernia. A fully biodegradable combination of implant and fibrin sealant fixation was assessed in a new rat model with sutures serving as control. METHODS: In 10 Sprague-Dawley rats, two defects per animal were created in the abdominal wall left and right of the linea alba (1 cm in diameter), and the peritoneum was spared. The lesions were left untreated for 10 days to achieve a chronic condition and were then covered with SIS (2 x 2 cm), sealed or sutured (n = 10 per group). Randomization allowed sealant and sutures in one animal. Animals were killed on postoperative day 17, and implant sites were analyzed macroscopically, histologically, and microbiologically. RESULTS: Abscedation, encapsulation, and putrid seroma were observed in all samples, regardless of fixation technique. Histology revealed lytic necrosis and extensive inflammatory response of the surrounding tissue. Tissue samples obtained from three implant sites were positive for beta-hemolytic Streptococcus. SIS was not detectable after 17 days. CONCLUSIONS: Adverse effects were observed using SIS in an experimental model of ventral hernia and were not linked to fixation method or study design. Further experimental investigations on SIS are necessary before its clinical use in hernia repair.

Fibrin sealing versus stapling of hernia meshes in an onlay model in the rat.

Incisional and inguinal hernia repair are among the most common procedures of general surgery. Mesh fixation by means of staples or sutures may lead to severe complications. The use of fibrin sealant (FS) has been suggested as alternative, but data on biocompatibility and adhesive strength of FS in combination with macroporous meshes is limited. Ventral hernia (n = 8 per group) was treated in rats in onlay technique with two types of meshes, fibrin sealed or stapled. TI-Mesh (TMxl) extralight and VYPROII (VPII) were tested 17 days post op. No failure in mechanical tests (tensile and burst strength) occurred in sealed or stapled meshes. Histology revealed equally good tissue integration and neovascularization in all groups. Fibrin sealant yields excellent fixation in experimental hernia repair. This rat model is suitable for testing meshes and fixation techniques.

Circulatory changes after prolonged ischemia in the epigastric flap.

The circulation system seems to have early encounters with pathophysiologic processes during ischemia and reperfusion, such as overproduction of oxygen radicals, nitric oxide depletion, and leukocyte plugging. The aim of this study was to determine the superficial perfusion and vessel distribution of the epigastric flap with a laser Doppler Imaging (LDI) system during ischemia/reperfusion, and to observe the clinical outcomes 7 days after reperfusion in a separate set of animals. An epigastric flap from male Sprague-Dawley rats (320 to 380 g) was used to assess perfusion in sham animals (n=6) or in 12 hr-ischemia animals (12 hr of ischemia and 3 hr of reperfusion, n = 10) with the LDI system. In a separate experiment, flap size, flap failure index, and histologic sections of the flap from sham animals (n=6) and 12-hr ischemia animals (n=6) were evaluated 7 days after reperfusion. Evaluation of the vessel distribution demonstrated a diffuse picture of flap perfusion after clamp release. Moreover, in the distal portion of the flap, circulation stopped immediately, resulting in a significantly decreased perfusion in the 12-hr ischemia animals during reperfusion, when compared with pre-surgical values (100 percent) or sham animals (77 +/- 26.5 vs. 108 +/- 9.6 percent PU). On day 7, the flaps of animals after ischemia and reperfusion showed significant shrinkage, an increase in flap failure index, as well as necrosis, edema, and leukocyte infiltration. Based on the findings, the authors propose that, after prolonged ischemia, the circulation becomes diffuse, and "no-reflow" occurs in the distal portions of the myocutaneous flap during reperfusion. Perfused areas, assessed with the LDI early during reperfusion, might still become necrotic after several days. In the authors' flap model, edema formation and leukocyte infiltration seem to be related more to ischemia reperfusion damage than to thrombus formation.