Extensor Pollicis Brevis Transosseous Tenodesis Technique for Treatment of Acquired Metacarpophalangeal Hyperextension Deformity of the Thumb: A Preliminary Report.

SUMMARY: Hyperextension deformity of the metacarpophalangeal joint of the thumb causes pain and loss of function. Although many treatments have been proposed, none of them are universally accepted as ideal. The authors report a study of 12 symptomatic hyperextension deformities of the thumb metacarpophalangeal joint in 10 patients who underwent surgical correction. The purpose of this study was to describe a new technique of tenodesis of the thumb metacarpophalangeal joint using the extensor pollicis brevis tendon. The technique consists of extensor pollicis brevis tenotomy at the wrist and tendon transfer through two bone tunnels to the palmar aspect of the metacarpophalangeal joint before metacarpal fixation with a flexor tenodesis effect. Correction of hyperextension and range of motion were assessed. Functional changes were evaluated by Quick Disabilities of the Arm, Shoulder, and Hand score, pain visual analogue scale, Kapandji opposition scheme, and pinch strength. The Wilcoxon test was used for statistical analysis. Mean preoperative and postoperative metacarpophalangeal joint hyperextension deformities were +50.83 ± 5.57 degrees and -17.91 ± 7.82 degrees, respectively. Thumb opposition improved by one point on Kapandji's scheme. Mean perceived pain decreased from 7.66 to 1.16. On average, the Quick Disabilities of the Arm, Shoulder, and Hand score was reduced by 34.4 points and pinch strength increased by 50.42 percent. The authors found that extensor pollicis brevis transosseous tenodesis is a safe and minimally invasive method for successfully correcting the functionality and cosmetic appearance of metacarpophalangeal joint hyperextension deformities in posttraumatic and trapeziometacarpal osteoarthritis cases. The patients retained functional active flexion, even in deformities greater than 40 degrees. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Improvement of Cell Culture Methods for the Successful Generation of Human Keratinocyte Primary Cell Cultures Using EGF-Loaded Nanostructured Lipid Carriers.

Human skin keratinocyte primary cultures can be established from skin biopsies with culture media containing epithelial growth factor (EGF). Although current methods are efficient, optimization is required to accelerate the procedure and obtain these cultures in less time. In the present study, we evaluated the effect of novel formulations based on EGF-loaded nanostructured lipid carriers (NLC). First, biosafety of NLC containing recombinant human EGF (NLC-rhEGF) was verified in immortalized skin keratinocytes and cornea epithelial cells, and in two epithelial cancer cell lines, by quantifying free DNA released to the culture medium. Then we established primary cell cultures of human skin keratinocytes with basal culture media (BM) and BM supplemented with NLC-rhEGF, liquid EGF (L-rhEGF), or NLC alone (NLC-blank). The results showed that cells isolated by enzymatic digestion and cultured with or without a feeder layer had a similar growth rate regardless of the medium used. However, the explant technique showed higher efficiency when NLC-rhEGF culture medium was used, compared to BM, L-rhEGF, or NLC-blank. Gene expression analysis showed that NLC-rhEGF was able to increase EGFR gene expression, along with that of other genes related to cytokeratins, cell-cell junctions, and keratinocyte maturation and differentiation. In summary, these results support the use of NLC-rhEGF to improve the efficiency of explant-based methods in the efficient generation of human keratinocyte primary cell cultures for tissue engineering use.

Biomechanical Finite Element Method Model of the Proximal Carpal Row and Experimental Validation.

The Finite Element Method (FEM) models are valuable tools to create an idea of the behavior of any structure. The complexity of the joints, materials, attachment areas, and boundary conditions is an open issue in biomechanics that needs to be addressed. Scapholunate instability is the leading cause of wrist pain and disability among patients of all ages. It is needed a better understanding of pathomechanics to develop new effective treatments. Previous models have emulated joints like the ankle or the knee but there are few about the wrist joint. The elaboration of realistic computational models of the carpus can give critical information to biomedical research and surgery to develop new surgical reconstructions. Hence, a 3D model of the proximal carpal row has been created through DICOM images, making a reduced wrist model. The materials, contacts, and ligaments definition were made via open-source software to extract results and carry on a reference comparison. Thus, considering the limitations that a reduced model could carry on (unbalanced forces and torques), the stresses that result in the scapholunate interosseous ligament (SLIL) lead us to a bones relative displacement, which support the kinematics hypothesis in the literature as the distal carpal row moves as a rigid solid with the capitate bone. Also, experimental testing is performed, successfully validating the linear strength values of the scapholunate ligament from the literature.

Modification of intra-carpal tunnel pressure after Z-lengthening of the transverse carpal ligament.

Background Flexor retinaculum reconstruction techniques or simply Flexor Retinaculum Z-lengthening have been proposed to preserve Flexor Retinaculum continuity after carpal tunnel release. Their effectiveness is based solely on symptom relief. There has been no analysis of the effects on intra-carpal tunnel pressure of Flexor Retinaculum-lengthening techniques. Objective was to compare intra-carpal tunnel pressure outcomes between complete division and Z-lengthening of the Retinaculum in a cadaveric model of carpal tunnel release. Methods Experimental study of carpal tunnel pressure after surgical Flexor Retinaculum modification in 10 fresh-frozen forearm and hand cadaveric specimens. The Kyphon™ Balloon Kyphoplasty system was used to measure the pressure before and after infusing 1, 2, 3, 4 and 5 ml of saline solution when untreated (Flexor Retinaculum continuity stage I), when Z-lengthened (Flexor Retinaculum continuity stage II), and after complete Flexor Retinaculum division (Flexor Retinaculum continuity stage III). Finding Intra-carpal tunnel pressure increased with larger volume of infused saline solution, although mean pressures were lower after Z lengthening or complete division of the Retinaculum than at baseline. Analysis of linear regression coefficients indicated significant differences as a function of FR continuity stage (F(2,18) = 18.38, p < 0.001), while the Bonferroni test revealed significant differences in slopes between stages I and III (p = 0.003), between stages I and II (p < 0.02), but not between stages II and III (p > 0.05). Interpretation The effectiveness of carpal tunnel release and the reduction in intra-carpal tunnel pressures obtained by Z-lengthening of the FR were similar to those observed after its complete division, while preserving FR continuity.

Expanded Differentiation Capability of Human Wharton's Jelly Stem Cells Toward Pluripotency: A Systematic Review.

Human Wharton's jelly stem cells (HWJSC) can be efficiently isolated from the umbilical cord, and numerous reports have demonstrated that these cells can differentiate into several cell lineages. This fact, coupled with the high proliferation potential of HWJSC, makes them a promising source of stem cells for use in tissue engineering and regenerative medicine. However, their real potentiality has not been established to date. In the present study, we carried out a systematic review to determine the multilineage differentiation potential of HWJSC. After a systematic literature search, we selected 32 publications focused on the differentiation potential of these cells. Analysis of these studies showed that HWJSC display expanded differentiation potential toward some cell types corresponding to all three embryonic cell layers (ectodermal, mesodermal, and endodermal), which is consistent with their constitutive expression of key pluripotency markers such as OCT4, SOX2, and NANOG, and the embryonic marker SSEA4. We conclude that HWJSC can be considered cells in an intermediate state between multipotentiality and pluripotentiality, since their proliferation capability is not unlimited and differentiation to all cell types has not been demonstrated thus far. These findings support the clinical use of HWJSC for the treatment of diseases affecting not only mesoderm-type tissues but also other cell lineages. Impact statement Human Wharton's jelly stem cells (HWJSC) are mesenchymal stem cells that are easy to isolate and handle, and that readily proliferate. Their wide range of differentiation capabilities supports the view that these cells can be considered pluripotent. Accordingly, HWJSC are one of the most promising cell sources for clinical applications in advanced therapies.

Scleral surgical repair through the use of nanostructured fibrin/agarose-based films in rabbits.

Scleral defects can result as a consequence of trauma, infectious diseases or cancer and surgical repair with allogeneic scleral grafts can be required. However, this method has limitations and novel alternatives are needed. Here, the efficacy of acellular nanostructured fibrin-agarose hydrogel-based substitutes (NFAH) in the repair of scleral defects in rabbits was studied. For this, scleral defects of 5-mm diameter were made on 18 adult-male New Zealand rabbits and repaired with acellular NFAH, NFAH crosslinked with genipin (NFAH-GP) or glutaraldehyde (NFAH-GA), allogeneic scleral grafts as control (C-CTR) or not repaired (negative control N-CTR) (n = 3 each). Macroscopic and histological analyses were performed after 40-days. Macroscopy confirmed the repair of all defects in a comparable manner than the C-CTR. Histology showed no degradation nor integration in C-CTR while NFAH-GP and NFAH-GA biomaterials were encapsulated by connective and inflammatory tissues with partial biodegradation. The NFAH were fully biodegraded and replaced by a loose connective tissue and sclera covering the defects. This in vivo study demonstrated that the NFAH are a promising biocompatible and pro-regenerative alternative to the use of allogeneic cadaveric grafts. However, large defects and long-term studies are needed to demonstrate the potential clinical usefulness of these substitutes.

Anatomic study of pedicled bipolar teres major transfer for irreparable posterosuperior rotator cuff tears.

BACKGROUND: Treatment of rotator cuff (RC) tears has not included bipolar muscle-tendon transfers to date. The objective of this study was to verify the feasibility of pedicled bipolar teres major (TM) transfer over and under the long head of the triceps brachii (LHT) and compare its versatility with monopolar transfer in a model of supraspinatus (SS) tears in cadavers. METHODS: In 6 shoulders of cryopreserved cadavers, we re-created complete SS tears, conducting monopolar and bipolar TM transfers over and under LHT. We compared the morphology of the SS and TM, defect coverage, angle between the transferred TM and major SS axis, and axillary nerve overlap with each technique. RESULTS: The TM and SS were morphologically similar. Defect coverage was significantly lower with monopolar transfer (12 ± 4 mm) than with bipolar transfer (39 ± 9 mm under the LHT, P = .003, and 38 ± 8 mm over the LHT, P = .004). The bipolar transfer course over the LHT was the nearest to the SS axis (39° ± 11°, P = .005). We found a greater axillary nerve overlap with bipolar transfer under the LHT (27 ± 8 mm) than with bipolar transfer over the LHT (1 ± 2 mm, P = .005) or monopolar transfer (0 mm, P < .001). CONCLUSION: Bipolar TM transfer is possible without neurovascular pedicle interference, obtaining greater RC defect coverage and the closest path to the SS axis when conducted over the LHT compared with monopolar or bipolar transfer under the LHT. Accordingly, it can be considered an alternative option for the treatment of posterosuperior RC defects.

Predicting successful prosthetic rehabilitation in major lower-limb amputation patients: a 15-year retrospective cohort study.

OBJECTIVE: To determine and compare specific factors that could be associated and predictive with successful prosthetic rehabilitation in major lower-limb amputations. METHODS: A 15-year long (2000-2014) retrospective observational cohort study was conducted. Two different criteria were used to define successful prosthetic rehabilitation: (1) the ability to walk at least 45m, regardless of assistive devices; and (2) walking >45m without other ambulatory aids than one cane (if required). Age, gender, comorbidities, cause and level of amputation, stump characteristics, ulcers in the preserved limb, and time between surgery and physical therapy were examined as predictors of successful prosthetic rehabilitation. RESULTS: A total of 169 patients (61.60±15.9 years) were included. Regarding walking ability with or without walking aids, the presence of ulcers in the preserved limb was individually associated with failed prosthetic rehabilitation (p<0.001), while being male (OR=0.21; 95%CI=0.06-0.80) and transtibial level of amputation (OR=6.73; 95%CI=1.92-23.64) were identified as independent predictors of failure and success, respectively. Regarding the criterion of successful rehabilitation, a shorter time until rehabilitation was individually associated with improved walking ability (p<0.013), while failure could be predicted by comorbidities (OR=0.48; 95%CI=0.29-0.78) and age groups of 65-75 years old (OR=0.19; 95%CI=0.05-0.78) and over 75 years old (OR=0.19; 95%CI=0.04-0.91). CONCLUSIONS: Regarding walking ability with or without walking aids, male gender and transtibial level of amputation are independently associated with failure and success respectively, whereas older age and comorbidities can predict failed prosthetic rehabilitation when assistive walking devices are considered. Future prospective cohort studies are needed to confirm these findings.

[Applicability of the da Vinci robotic system in the skull base surgical approach. Preclinical investigation]. / Aplicabilidad del sistema da Vinci en el abordaje transoral a la base del cráneo. Investigación preclínica.

INTRODUCTION: The role of robotic surgery is well established in various specialties such as urology and general surgery, but not in others such as neurosurgery and otolaryngology. In the case of surgery of the skull base, it has just emerged from an experimental phase. OBJECTIVE: To investigate possible applications of the da Vinci surgical robot in transoral skull base surgery, comparing it with the authors' experience using conventional endoscopic transnasal surgery in the same region. METHODS: A transoral transpalatal approach to the nasopharynx and medial skull base was performed on 4 cryopreserved cadaver heads. We used the da Vinci robot, a 30° standard endoscope 12mm thick, dual camera and dual illumination, Maryland forceps on the left terminal and curved scissors on the right, both 8mm thick. Bone drilling was performed manually. For the anatomical study of this region, we used 0.5cm axial slices from a plastinated cadaver head. RESULTS: Various skull base structures at different depths were reached with relative ease with the robot terminals CONCLUSIONS: Transoral robotic surgery with the da Vinci system provides potential advantages over conventional endoscopic transnasal surgery in the surgical approach to this region.

Lysophosphatidic acid pretreatment prevents micromolar atorvastatin-induced endothelial cell death and ensures the beneficial effects of high-concentration statin therapy on endothelial gene expression.

Because of the pleiotropic effects of statins, it may potentially be used as a locoregional adjuvant in vascular revascularization, tissue engineering, and regenerative procedures. Electron probe X-ray microanalyses and oligonucleotide microarrays were used to identify the global effects of micromolar concentrations of atorvastatin on the gene expression and cell viability of endothelial cells in different states of lysophosphatidic acid (LPA)-induced activation. Treatment with 1-µM atorvastatin for 24 hours significantly reduced the viability of human vascular endothelial cells (HUVECs). However, the same treatment of LPA-preactivated HUVECs produced elevated cell viability levels and an optimal vascular gene expression profile, including endothelial nitric oxide synthase overexpression, endothelin-1 repression, an anti-inflammatory genetic pattern, and upregulation of molecules involved in maintaining the endothelial barrier (vascular endothelial cadherin, claudin 5, tight junction protein 1, integrin ß4). The atorvastatin treatment also produced a repression of microRNA 21 and genes involved in cell proliferation and neointimal formation (vascular endothelial growth factor [VEGF] A, VEGF receptor 1, VEGFC). Results obtained suggest that micromolar atorvastatin therapy can enhance global endothelial function, but its effects on cell viability vary according to the baseline state of cell activation (preactivated, postactivated, or not activated). Preactivation with LPA protects HUVECs against atorvastatin-induced apoptosis and delivers optimal levels of cell viability and functionality.

Expression of smoothelin and smooth muscle actin in the skin.

INTRODUCTION: Smoothelin is a cytoskeletal protein of differentiated smooth muscle cells with contractile capacity, distinguishing it from other smooth muscle proteins, such as smooth muscle actin (SMA). OBJECTIVE: To evaluate the expression of smoothelin and SMA in the skin in order to establish specific localizations of smoothelin in smooth muscle cells with high contractile capacity and in the epithelial component of cutaneous adnexal structures. METHODS: Immunohistochemical analysis (smoothelin and SMA) was performed in 18 patients with normal skin. RESULTS: SMA was expressed by the vascular structures of superficial, deep, intermediate and adventitial plexuses, whereas smoothelin was specifically expressed in the cytoplasm of smooth muscle cells of the deepest vascular plexus and in no other plexus of the dermis. The hair erector muscle showed intense expression of smoothelin and SMA. Cells with nuclear expression of smoothelin and cytoplasmic expression of SMA were observed in the outer root sheath of the inferior portion of the hair follicles and intense cytoplasmic expression in cells of the dermal sheath to SMA. CONCLUSIONS: We report the first study of smoothelin expression in normal skin, which differentiates the superficial vascular plexus from the deep. The deep plexus comprises vessels with high contractile capacity, which is important for understanding dermal hemodynamics in normal skin and pathological processes. We suggest that the function of smoothelin in the outer root sheath may be to enhance the function of SMA, which has been related to mechanical stress. Smoothelin has not been studied in cutaneous pathology; however we believe it may be a marker specific for the diagnosis of leiomyomas and leiomyosarcomas of the skin. Also, smoothelin could differentiate arteriovenous malformations of cavernous hemangioma of the skin.

Relevance of human anatomy in daily clinical practice.

AIM: the aim of this study has been to evaluate the relevance of gross human anatomy in daily clinical practice and to compare it to that of other basic sciences (biochemistry, bioethics, cytohistology, microbiology, pharmacology, physiology, psychology). MATERIALS AND METHODS: a total of 1250 questionnaires were distributed among 38 different medical speciality professionals. Answers were analyzed taking into account speciality (medical, surgery and others), professional status (training physician or staff member) and professional experience. RESULTS: the response rate was 42.9% (n=536). Gross human anatomy was considered the most relevant basic discipline for surgical specialists, while pharmacology and physiology were most relevant for medical specialists. Knowledge of anatomy was also considered fundamental for understanding neurological or musculoskeletal disorders. In undergraduate programmes, the most important focuses in teaching anatomy were radiological, topographical and functional anatomy followed by systematic anatomy. In daily medical practice anatomy was considered basic for physical examination, symptom interpretation and interpretation of radiological images. When professional status or professional experience was considered, small variations were shown and there were no significant differences related to gender or community. CONCLUSION: our results underline the relevance of basic sciences (gross anatomy, physiology, and pharmacology) in daily professional activity. Evidence-based studies such as ours, lend greater credibility and objectivity to the role of gross anatomy in the undergraduate training of health professionals and should help to establish a more appropriate curriculum for future professionals.

Anatomía cuantitativa del ductus arteriosus. Período fetal humano(100-1 500g de peso somático) patrones de normalidad(I) / Quantitative anatomy of ductus arteriosus fetal human period (100-1500 g of somatic weight) pattern of normality

Se estudiaron 193 corazones humanos, pertenecientes a fetos cuyos pesos somáticos oscilaban desde 100 hasta 1 500 gramos inclusive, de los cuales 114 eran varones y 79 hembras; todos ellos fueron diagnosticaron de anatómicamente normales y con este material se ha estudiado la anatomía cuantitativa del ductus arteriosus. Se obtuvieron 4 parámetros cuyos patrones de normalidad en sus valores mínimos,medio y máximo son expuestos. La configuración anatomogeométrica de esta estructura es comparable con un tronco de cono. Los patrones han sido agrupados en intervalos de 100 gramos y son considerados de utilidad para establecer estudios comparativos con las medidas obtenidas por las técnicas ecocardiográficas actuales, que permiten poder realizar la cirugía fetal con grandes posibilidades de éxito.