Risk Factors for Nonunion After Distal Phalangeal Fractures of the Hand.

PURPOSE: This study aimed to evaluate the risk factors for distal phalanx fracture nonunion. METHODS: We retrospectively reviewed all adult patients treated for distal phalanx fractures at our institution between January 2015 and December 2019 with a minimum one-year follow-up period for potential risk factors. The absence of consolidation signs on follow-up radiographs at least 12 months after trauma was defined as nonunion. RESULTS: This study included 124 patients with 143 fractures available for follow-up. Nonunion was diagnosed in 19 patients, 18 of whom initially presented with an open fracture. On the day of the injury, 17 patients with open fractures presented to the hospital. In 16 nonunion cases, the traumatic mechanism was a crush injury. All nonunions occurred in tuft fractures, and none required revision surgery at the follow-up visit. CONCLUSIONS: Our findings suggest that tuft involvement in open fractures is the main risk factor for nonunion of distal phalangeal fractures. However, after a minimum of 1 year of follow-up, none of the tuft nonunions required revision surgery. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Extensive Convexity Flattening of a Synthetic Skull Implant the Overcome Major Scalp Deficiency After Multiple Craniotomies.

ABSTRACT: Multiple craniofacial surgeries and postoperative recalcitrant infections frequently can lead to secondary scalp tissue scarring and skin retraction. Although there are different methods of reducing and optimizing scalp skin tension, the authors describe a last resort treatment method of cranioplastic procedure, which despite of its unfavorable cosmetic outcome, relieves the skin tension through extensive flattening of the polyetheretherketone curvature. Thereby, a custom-made cranioplastic bone flap was extensively flattened in the curvature of the fronto-parietal area with consideration of the related brain hemisphere extension. The extent of bone curvature flatting reduced the skin tension significantly and allowed for plain and simple tension-free wound closure in a chronic smoker patient with poor skin quality and brain atrophy. Although brain extension was sufficient, the cosmetic outcome was unfavorable with regard to skull symmetry, but well accepted and satisfactory for the patient due to preoperative discussion outcome expectation from surgery. Thus, extensive polyetheretherketone curvature flattening is a straightforward and simple last resort treatment option for tension-free skin closure in high-risk patients with extensive skin scarring and retraction and previous reconstructive plastic skin relief procedures. However, this method is limited in patients with normal brain hemisphere extension.

Endoscopic Carpal Tunnel Release Using Wide-Awake Anesthesia.

Purpose: We report on patient and surgeon experience after single-port endoscopic carpal tunnel release (CTR) using wide-awake local anesthesia no tourniquet (WALANT) technique. Methods: From July to November 2018, patients undergoing endoscopic CTR with WALANT were prospectively included. Follow-up was 3 months. Patient ratings before, during, and after the operation were collected. We recorded the surgeon's experience during surgery compared with the endoscopic CTR under local anesthesia with exsanguination and tourniquet. Complications were defined as nerve injury, infection, or the need for revision surgery. Results: The cohort consisted of 20 patients (24 wrists). All patients except one reported a complete or substantial decrease of symptoms. The 2 surgeons involved judged the procedure to be technically more demanding owing to impaired visualization (33%) caused by increased bleeding and edema in the operative field. There was one conversion from endoscopic to open surgery. Conclusions: We recommend starting single-port endoscopic CTR using WALANT with a noninflated tourniquet in place for use when necessary. Type of study/level of evidence: Therapeutic IV.

Ochrobactrum anthropi Infection of the Hand.

Ochrobactrum anthropi is an opportunistic, low-virulence pathogen occasionally associated with human infections and found largely in immunocompromised patients and those with intravascular devices. We report the case of a healthy 70-year-old man who presented with an infection of the hand, who had no history of trauma but had been gardening for 4 months. Despite surgical debridement and empirical antibiotics, the infection could not be controlled. Cultures revealed O anthropi. Antibiotic treatment was adapted to intravenous cefepime for 15 days and the infection was finally controlled after a second surgery. Oral cotrimoxazole was continued for another 2 weeks. Ochrobactrum anthropi infection of the hand must be considered not only in immunosuppressed patients but also in healthy patients without intravascular devices. Local debridement and empiric antibiotic may be insufficient. Antibiotic therapy should follow susceptibility testing, but usually includes a broad-spectrum intravenous beta-lactam such as imipenem-cilastatin or cefepime, or oral cotrimoxazole or ciprofloxacin.

In utero Plastic Surgery in Zurich: Successful Use of Distally Pedicled Random Pattern Transposition Flaps for Definitive Skin Closure during Open Fetal Spina Bifida Repair.

BACKGROUND: One of the intraoperative challenges of fetal spina bifida repair is skin closure when there is an extended skin defect. Thus, we examined whether distally pedicled random pattern transposition flaps (TFs) are a valid option to overcome this problem. SUBJECTS AND METHODS: All patients undergoing in utero repair of spina bifida with application of a TF for back skin closure were analyzed focusing on intraoperative flap characteristics and postoperative flap performance. RESULTS: In 30 (70%) of the 43 fetuses a primary skin closure was achieved, in 5 (12%) a skin substitute was used, and in 8 (18%) a TF was applied. Flap raising and insertion was uneventful and perfusion was sufficient in all 8 fetuses (100%). In 3 fetuses (37%) the donor sites were closed primarily, and in 5 (63%) a skin substitute was used for coverage. At birth, 7 flaps were viable and provided robust skin coverage over the center of the former lesion. Complications included a small skin defect with CSF leakage in 1 patient (13%). CONCLUSION: During open fetal spina bifida repair, TFs can be safely and efficaciously used to obtain solid and durable skin coverage over lesions too large to allow conventional primary skin closure.

Diffuse Dermal Angiomatosis of the Breast: A Distinct Entity in the Spectrum of Cutaneous Reactive Angiomatoses - Clinicopathologic Study of Two Cases and Comprehensive Review of the Literature.

Diffuse dermal angiomatosis (DDA) is a rare reactive angioproliferation in the skin and considered to be a subtype in the group of cutaneous reactive angiomatoses. DDA is clinically characterized by livedoid patches and plaques with tender ulceration. Its histologic features are a reactive diffuse proliferation of bland endothelial cells and pericytes within the dermis, forming small capillary vessels. Previously described cases of DDA most commonly involved the limbs and were associated with a wide spectrum of predisposing comorbidities, especially advanced atherosclerotic vascular disease and arteriovenous fistula. However, several cases of DDA of the breast (DDAB) have been reported in recent years. In this study we present 2 additional patients with DDAB and review all 36 cases of DDAB published in the literature. We describe the clinical and histopathologic characteristics, hypothesized pathogenetic mechanisms, and predisposing conditions of this rare skin disorder and discuss treatment options. The breast is a more commonly involved site of DDA than previously believed. DDAB typically occurs in middle-aged women and is associated with macromastia, overweight or obesity, and probably smoking. Predisposing comorbid conditions differ from those of DDA involving other parts of the body, making DDAB a unique clinicopathologic entity in the spectrum of cutaneous reactive angiomatoses. Currently there is no consensus on the best therapeutic approach. Isotretinoin and other medical therapies have been used with limited success. Breast reduction surgery appears to be a viable treatment option for DDAB in women with macromastia and might provide definitive healing.

Human Adipose Mesenchymal Cells Inhibit Melanocyte Differentiation and the Pigmentation of Human Skin via Increased Expression of TGF-ß1.

There is accumulating evidence that interactions between epidermal melanocytes and stromal cells play an important role in the regulation of skin pigmentation. In this study we established a pigmented dermo-epidermal skin model, melDESS, of human origin to investigate the effects of distinct stromal cells on melanogenesis. melDESS is a complex, clinically relevant skin equivalent composed of an epidermis containing both melanocytes and keratinocytes. Its dermal compartment consists either of adipose tissue-derived stromal cells, dermal fibroblasts (Fbs), or a mixture of both cell types. These skin substitutes were transplanted for 5 weeks on the backs of immuno-incompetent rats and analyzed. Gene expression and Western blot analyses showed a significantly higher expression of transforming growth factor-ß1 by adipose tissue-derived stromal cells compared with dermal Fbs. In addition, we showed that melanocytes responded to the increased levels of transforming growth factor-ß1 by down-regulating the expression of key melanogenic enzymes such as tyrosinase. This caused decreased melanin synthesis and, consequently, greatly reduced pigmentation of melDESS. The conclusions are of utmost clinical relevance, namely that adipose tissue-derived stromal cells derived from the hypodermis fail to appropriately interact with epidermal melanocytes, thus preventing the sustainable restoration of the patient's native skin color in bioengineered skin grafts.

Characterization of vasculogenic potential of human adipose-derived endothelial cells in a three-dimensional vascularized skin substitute.

PURPOSE: The need for clinically applicable skin substitutes continues to be a matter of fact. Hypothetically, a laboratory grown autologous skin analog with near normal architecture might be a suitable approach to yield both satisfactory functional and cosmetic long-term results. In this study, we explored the use of human endothelial cells derived from freshly isolated adipose stromal vascular fraction (SVF) in a three-dimensional (3D) co-culture model of vascularized bio-engineered skin substitute. METHODS: The SVF was isolated from human white adipose tissue samples and keratinocytes from human skin biopsies. The SVF, in particular endothelial cells, were characterized using flow cytometry and immuofluorescence analysis. Endothelial and mesenchymal progenitors from the SVF formed blood capillaries after seeding into a 3D collagen type I hydrogel in vitro. Subsequently, human keratinocytes were seeded on the top of those hydrogels to develop a vascularized dermo-epidermal skin substitute. RESULTS: Flow cytometric analysis of surface markers of the freshly isolated SVF showed the expression of endothelial markers (CD31, CD34, CD146), mesenchymal/stromal cell-associated markers (CD44, CD73, CD90, CD105), stem cell markers (CD49f, CD117, CD133), and additionally hematopoietic markers (CD14, CD15, CD45). Further analysis of white adipose-derived endothelial cells (watECs) revealed the co-expression of CD31, CD34, CD90, CD105, and partially CD146 on these cells. WatECs were separated from adipose-stromal cells (watASCs) using FACS sorting. WatASCs and watECs cultured separately in a 3D hydrogel for 3 weeks did not form any vascular structures. Only if co-cultured, both cell types aligned to develop a ramified vascular network in vitro with continuous endothelial lumen formation. Transplantation of those 3D-hydrogels onto immuno-incompetent rats resulted in a rapid connection of human capillaries with the host vessels and formation of functional, blood-perfused mosaic human-rat vessels within only 3-4 days. CONCLUSIONS: Adipose tissue represents an attractive cell source due to the ease of isolation and abundance of endothelial as well as mesenchymal cell lineages. Adipose-derived SVF cells exhibit the ability to form microvascular structures in vitro and support the accelerated blood perfusion in skin substitutes in vivo when transplanted.

The Frontal View of the Nose: Lighting Effects and Photographic Bias.

BACKGROUND: Most aesthetic rhinosurgeons rely on proper photographic documentation of the nose using several different views. The frontal view is probably the most important, but it is also the most demanding. OBJECTIVES: In the frontal view, delicate, 3-dimensional (3D) anatomic structures require special photographic skills. Lighting is crucial for detail rendition and 3D reproduction of the nose, and for apparent photographic bias. METHODS: We compared the quality of reproduction and photographic bias with different symmetric and asymmetric lighting in common clinical practice described in the literature. The photographs were compared for anatomic reproduction, shadowing, 3-dimensionality, and apparent changes of nasal shape (bias). RESULTS: Symmetric lighting did not satisfy the demands of the rhinosurgeons because of marginal 3-dimensionality, reduced detail rendition, or photographic bias. Strongly asymmetric lighting altered the nasal shape adversely for bias depending on the side of illumination, but led to very good 3-dimensionality. Slightly asymmetric lighting demonstrated the best results for detail rendition and 3-dimensionality. CONCLUSIONS: Classic symmetric quarter light is a practicable lighting technique with limitations in the rendition of detail and 3-dimensionality. Slightly asymmetric lighting offered a perfect compromise, with substantially improved detail rendition and 3-dimensionality. Strongly asymmetric lighting may lead to photographic bias depending on the side of illumination. Frontal documentation of the nose with asymmetric lighting should, therefore, always be performed in duplicate, with asymmetric lighting from the right side and from the left side, to prevent misleading interpretations.

Simultaneous proximal interphalangeal joint arthroplasty and extensor tendon reconstruction in adjacent fingers: case report.

We present a case of a young man with heavily injured proximal interphalangeal joints and deficits of the extensor mechanism in 2 fingers treated by silicone proximal interphalangeal joint arthroplasty and 2-stage reconstruction of the extensor mechanism. The postoperative result was satisfactory with a painless, if limited, active arc of motion of the proximal interphalangeal joints of 50° in the middle finger and 35° in the ring finger.

Tissue-engineered dermo-epidermal skin grafts prevascularized with adipose-derived cells.

The major problem in skin grafting is that tissue-engineered skin grafts after their transplantation are initially entirely dependent on diffusion. Since this process is slow and inefficient, nutrients, growth factors, and oxygen will insufficiently be supplied and the regenerating graft will undergo a physiological crisis, resulting in scar-like dermal structures and shrinkage. The tissue-engineering of a vascular network in human dermo-epidermal skin substitutes (DESS) is a promising approach to overcome this limitation. Here we report, for the first time, on the use of the adipose stromal vascular fraction (SVF)-derived endothelial cell population to tissue-engineer DESS containing a highly efficient capillary plexus. To develop vascular networks in vitro, we employed optimized 3D fibrin or collagen type I hydrogel systems. Upon transplantation onto immune-deficient rats, these pre-formed vascular networks anastomosed to the recipient's vasculature within only four days. As a consequence, the neo-epidermis efficiently established tissue homeostasis, the dermis underwent almost no contraction, and showed sustained epidermal coverage in vivo. Overall, the here described rapid and efficient perfusion of SVF-based skin grafts opens new perspectives for the treatment of hitherto unmet clinical needs in burn/plastic surgery and dermatology.

De novo epidermal regeneration using human eccrine sweat gland cells: higher competence of secretory over absorptive cells.

In our previous work, we showed that human sweat gland-derived epithelial cells represent an alternative source of keratinocytes to grow a near normal autologous epidermis. The role of subtypes of sweat gland cells in epidermal regeneration and maintenance remained unclear. In this study, we compare the regenerative potential of both secretory and absorptive sweat gland cell subpopulations. We demonstrate the superiority of secretory over absorptive cells in forming a new epidermis on two levels: first, the proliferative and colony-forming efficiencies in vitro are significantly higher for secretory cells (SCs), and second, SCs show a higher frequency of successful epidermis formation as well as an increase in the thickness of the formed epidermis in the in vitro and in vivo functional analyses using a 3D dermo-epidermal skin model. However, the ability of forming functional skin substitutes is not limited to SCs, which supports the hypothesis that multiple subtypes of sweat gland epithelial cells hold regenerative properties, while the existence and exact localization of a keratinocyte stem cell population in the human eccrine sweat gland remain elusive.

Premiere use of Integra™ artificial skin to close an extensive fetal skin defect during open in utero repair of myelomeningocele.

BACKGROUND: There are fetuses demonstrating very large myelomeningocele lesion which can not be covered with autochothonous skin. MATERIAL AND METHODS: We use Integra™ artificial skin for intrauterine coverage of the back lesion. A reverse latissimus dorsi flap was used postnatally to reinforce the repair site. CONCLUSION: Integra™ appears to be a suitable coverage for large soft tissue defects in utero. Moreover, a postnatal reverse latissimus dorsi flap appears to markedly strengthen tissue coverage over a spinal cord rescued in utero.

Human eccrine sweat gland cells turn into melanin-uptaking keratinocytes in dermo-epidermal skin substitutes.

Recently, Biedermann et al. (2010) have demonstrated that human eccrine sweat gland cells can develop a multilayered epidermis. The question still remains whether these cells can fulfill exclusive and very specific functional properties of epidermal keratinocytes, such as the incorporation of melanin, a feature absent in sweat gland cells. We added human melanocytes to eccrine sweat gland cells to let them develop into an epidermal analog in vivo. The interaction between melanocytes and sweat gland-derived keratinocytes was investigated. The following results were gained: (1) macroscopically, a pigmentation of the substitutes was seen 2-3 weeks after transplantation; (2) we confirmed the development of a multilayered, stratified epidermis with melanocytes distributed evenly throughout the basal layer; (3) melanocytic dendrites projected to suprabasal layers; and (4) melanin was observed to be integrated into former eccrine sweat gland cells. These skin substitutes were similar or equal to skin substitutes cultured from human epidermal keratinocytes. The only differences observed were a delay in pigmentation and less melanin uptake. These data suggest that eccrine sweat gland cells can form a functional epidermal melanin unit, thereby providing striking evidence that they can assume one of the most characteristic keratinocyte properties.

"Trooping the color": restoring the original donor skin color by addition of melanocytes to bioengineered skin analogs.

PURPOSE: Autologous skin substitutes to cover large skin defects are used since several years. Melanocytes, although essential for solar protection and pigmentation of skin, are not yet systematically added to such substitutes. In this experimental study, we reconstructed melanocyte-containing dermo-epidermal skin substitutes from donor skins of different skin pigmentation types and studied them in an animal model. Features pertinent to skin color were analyzed and compared in both skin substitutes and original donor skin. METHODS: Keratinocytes, melanocytes, and fibroblast were isolated, cultured, and expanded from skin biopsies of light- and dark-pigmented patients. For each donor, melanocytes and keratinocytes were seeded in different ratios (1:1, 1:5, 1:10) onto collagen gels previously populated with autologous fibroblasts. Skin substitutes were then transplanted onto full-thickness wounds of immuno-incompetent rats. After 8 weeks, macroscopic and microscopic analyses were conducted with regard to skin color and architecture. RESULTS: Chromameter evaluation revealed that skin color of reconstructed light- and dark-pigmented skin was very similar to donor skin, independent of which melanocyte/keratinocyte ratio was added. Histological analyses of the skin analogs confirmed these findings. CONCLUSION: These data suggest that adding autologous melanocytes to bioengineered dermo-epidermal skin analogs can sustainably restore the patients' native skin color.

Rebuild, restore, reinnervate: do human tissue engineered dermo-epidermal skin analogs attract host nerve fibers for innervation?

PURPOSE: Tissue engineered skin substitutes are a promising tool to cover large skin defects, but little is known about reinnervation of transplants. In this experimental study, we analyzed the ingrowth of host peripheral nerve fibers into human tissue engineered dermo-epidermal skin substitutes in a rat model. Using varying cell types in the epidermal compartment, we wanted to assess the influence of epidermal cell types on reinnervation of the substitute. METHODS: We isolated keratinocytes, melanocytes, fibroblasts, and eccrine sweat gland cells from human skin biopsies. After expansion, epidermal cells were seeded on human dermal fibroblast-containing collagen type I hydrogels as follows: (1) keratinocytes only, (2) keratinocytes with melanocytes, (3) sweat gland cells. These substitutes were transplanted into full-thickness skin wounds on the back of immuno-incompetent rats and were analyzed after 3 and 8 weeks. Histological sections were examined with regard to myelinated and unmyelinated nerve fiber ingrowth using markers such as PGP9.5, NF-200, and NF-145. RESULTS: After 3 weeks, the skin substitutes of all three epidermal cell variants showed no neuronal ingrowth from the host into the transplant. After 8 weeks, we could detect an innervation of all three types of skin substitutes. However, the nerve fibers were restricted to the dermal compartment and we could not find any unmyelinated fibers in the epidermis. Furthermore, there was no distinct difference between the constructs resulting from the different cell types used to generate an epidermis. CONCLUSION: Our human tissue engineered dermo-epidermal skin substitutes demonstrate a host-derived innervation of the dermal compartment as early as 8 weeks after transplantation. Thus, our substitutes apparently have the capacity to attract nerve fibers from adjacent host tissues, which also grow into grafts and thereby potentially restore skin sensitivity.

Subdivision of the sural nerve: step towards individual facial reanimation.

Long term facial paralysis is a serious affliction and upsetting for the patient. Dynamic facial reanimation has become the treatment of choice. Various techniques that use different donor muscles have been developed since the first functional muscle transplant for facial paralysis more than 30 years ago. The concept of using a single muscle was refined into the use of dividable muscle slips such as serratus muscle or separate muscular subunits to avoid the resulting mass movements. Because the results are still not satisfactory, efforts were put into also dividing the donor nerve transplant into corresponding subunits to create a continuous line of individual action. Twenty human cadaveric sural nerves were successfully dissected into three completely separate subunits, transecting the interfascicular bridges. This anatomical study gives the potential to allow an independent triple innervation of three separate serratus anterior muscle slips, so decreasing further the mass movement after facial reanimation.

The value of ultrasonography in hand surgery.

The quality of ultrasound imaging to examine anatomical structures in the wrist and hand has improved highly over the last years. The value of ultrasonography (US) performed by hand surgeons on treatment decisions was investigated in this study. One hundred and ninety-five patients with an unclear clinical hand problem were evaluated by high-definition ultrasonography from January 2005 until June 2007. In 21% of cases, the procedure and therapy were influenced by the ultrasonographic findings. In 26 patients examined by ultrasound, surgery was avoided, while 14 patients had unexpected ultrasound results that led to surgery. In 22 of the 84 performed operations, ultrasound had a direct impact on the surgical procedure itself. The agreement of the ultrasonographic diagnosis and the post-operative diagnosis (n = 80) was better, though not statistically significant compared to the agreement between clinical diagnosis and diagnosis after operation (n = 84). Ultrasound imaging performed by the hand surgeon improves quality in the evaluation of hand problems. Ultrasonography is a cost-effective high-resolution investigation with the possibility of dynamic imaging.

Frequency and conduction velocity analysis of the abductor pollicis brevis muscle during early fatigue.

The physiological behavior of the abductor pollicis brevis (APB) muscle during early stage of fatigue is important as a reference for future clinical assessment of a pathologically altered muscle, as e.g. in carpal tunnel syndrome. The purpose of this study was to assess changes of force and surface electromyograms (sEMG) during early stage of fatigue of the APB. Thumb abduction force and sEMG derived from a multi-electrode array were recorded during isometric contraction. Electrode placement over the innervation zone (IZ) and the muscle tendon interface were avoided. The sEMGs of two adjacent electrode pairs were selected for the analysis, which yielded (a) motor unit conduction velocities (MUCV) derived from a correlation analysis between the EMGs and (b) mean frequencies obtained by using either fast Fourier (FMF) or Wavelet Transform (WMF). Early fatigue resulted in a relative decay rate of force (-2.1%( *)s(-1)), MUCV (-1.5%( *)s(-1)), FMF (-4.1%( *)s(-1)), WMF (-3.7%( *)s(-1)) and in a change of the power spectrum shape. Lower mean frequencies were observed at greater distances from the IZ independently of fatigue. The APB muscle seems to be fast fatigable and the relative decay rate of mean frequency was significantly larger than the one of force and MUCV.