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Titanium-based scaffolds are widely used implant materials for bone defect treatment. However, the unmatched biomechanics and poor bioactivities of conventional titanium-based implants usually lead to insufficient bone integration. To tackle these challenges, it is critical to develop novel titanium-based scaffolds that meet the bioadaptive requirements for load-bearing critical bone defects. Herein, inspired by the microstructure and mechanical properties of natural bone tissue, we developed a Ti–6Al–4V alloy (TC4)/gelatin methacrylate (GelMA) hybrid scaffold with dual bionic features (GMPT) for bone defect repair. GMPT is composed of a hard 3D-printed porous TC4 metal scaffold (PT) backbone, which mimics the microstructure and mechanical properties of natural cancellous bone, and a soft GelMA hydrogel matrix infiltrated into the pores of PT that mimics the microenvironment of the extracellular matrix. Ascribed to the unique dual bionic design, the resultant GMPT demonstrates better osteogenic and angiogenic capabilities than PT, as confirmed by the in vitro and rabbit radius bone defect experimental results. Moreover, controlling the concentration of GelMA (10%) in GMPT can further improve the osteogenesis and angiogenesis of GMPT. The fundamental mechanisms were revealed by RNA-Seq analysis, which showed that the concentration of GelMA significantly influenced the expression of osteogenesis- and angiogenesis-related genes via the Pi3K/Akt/mTOR pathway. The results of this work indicate that our dual bionic implant design represents a promising strategy for the restoration of large bone defects., Graphical abstract Image 1, Highlights • A novel TC4/GelMA hybrid scaffold (GMPT) was designed to mimic natural bone microstructure and mechanical property. • The GMPT with 10 wt% of GelMA showed best capability for promoting osteogenesis and angiogenesis. • A bioactive soft surface with suitable stiffness can activate focal adhesion pathway and the downstream PI3K/AKT pathway.

Ulnar dimelia is a rare congenital anomaly of the upper extremity. The condition presents with double ulnae forearm and polydactyly with complete absence of radius bone and thumb. Clinically it presents not only as functional deformity but also as cosmetic deformity. The case presented here is of a one-and-a-half-year-old male baby, born with right side ulnar dimelia with no other musculoskeletal defect. We believe that the case presented here deserves reporting not only because of the rarity of the disease but also due to its difficult management requiring multiple staged operations and henceforth consequent neglect on the part of parents. An attempt is also made to do a brief literature review. Keywords: Ulnar dimelia; polydactyly; ulna; radius; thumb

Objectives This study aims to mechanically compare five different extra-focal bi-cortical pin configurations (using two and three pins) employed for fixation of a simulated unstable extra-articular distal radius fracture with dorsal comminution using a sawbone model. Materials and methods This in vitro mechanical study was conducted between June 2019 and July 2019. A standard fracture model (Arbeitsgemeinschaft für Osteosynthesefragen [AO] type 23-A3.3) was created using a fourth generation composite artificial radius bone. Five groups with two- and three-pin configurations were tested under axial, volar, and dorsal loading with a universal test device. Mean stiffness values were compared statistically. Results Comparison of stiffness values from axial and volar loading tests between groups in paired comparison showed no statistically significant difference (p=0.194 and p=0.086, respectively). Dorsal loading tests showed statistically significant difference between the groups in pairwise comparison (p=0.002). Three-pin groups (Groups 3, 4, and 5) had higher stiffness values compared to two-pin groups (Groups 1 and 2) in dorsal loading tests (p=0.001). Three-pin configuration test groups with two divergent or convergent pins from the radial styloid performed better compared to both two-pin groups (p=0.01, p=0.002) in dorsal loading tests. Conclusion Our data demonstrated that the three-pin configuration with two divergent or convergent Kirschner wires from the styloid and a third wire from the dorsal/ulnar cortex had higher stiffness values compared to two-pin configurations in dorsal loading tests. When indicated, we suggest the use of a three-pin construct. Particularly in cases with a risk of volar angulation, we recommend a three-pin configuration with two divergent or convergent bi-cortical Kirschner wires.

Objective: Partial dislocation of radius head (pulled elbow) is the most common trauma observed in out-patient orthopedic treatment of children. The typical mechanism of this trauma includes exertion of longitudinal force along the forearm in a pronation position, causing partial dislocation of the radius head. Methods: This Retrospective descriptive and cross-sectional study was undertaken on patients referring to the emergency ward of Imam Reza hospital of Mashhad with typical history of partial dislocation of radius head (pulled elbow). The present study was conducted between March 20, 2018 and March 20, 2019. Based on the number of patients at the emergency ward, the sample size was determined to be 80. Descriptive statistics such as mean and standard deviation were used to describe the collected data. Results: From among 80 children diagnosed with partial radius bone dislocation, 66.23% were girls and 33.77% were boys. The age range of patients was 28.08 months for girls and 31.04 months for boys. Findings also showed that 32 patients had a history of recent respiratory infection within 1 week before the pulled elbow incident. Conclusion: Findings revealed that, similar to previous studies, the pulled elbow injury was more common in girls than in boys. Successful reduction in first and second attempts, notwithstanding the maneuvers used indicated that the success rate of first attempts at reduction was 93%. The history of recent respiratory infections during 1 week before the injury was taken into account, where 40% of the children had some history of such respiratory infections.

The treatment of delayed union and established nonunion of the scaphoid using a volar approach with impaction of bone graft, either a cancellous or cortico-cancellous wedge graft, for osteosynthesis and maintenance of reduction. With the advancement of instruments and techniques of wrist arthroscopy, wider indications for wrist problems can be solved by this minimally invasive technique. We report our results of arthroscopic reduction, cancellous bone grafting to the regional distal radius, and headless screw fixation for the treatment of scaphoid nonunion, even with humpback deformity. Between August 2014 and February 2018, 41 patients (42 wrists) with unstable scaphoid nonunion received arthroscopic surgery. The mean follow-up was 38.1 months (range 24–70 months). We evaluated the results with a function questionnaire and clinical outcomes based on the visual analog scale (VAS) pain score, range of motion and grip strength, and radiologic measurements. The union rate was 92.6% (38/41 patients) and union time was 4.6 months. Patients regained almost a full range of motion compared with the contralateral wrist. The post-op Quick DASH, Mayo wrist score, and VAS pain score all had significant improvement, with p

Bone plates are used to treat bone fractures by stabilizing the fracture site and allowing treatments to take place. Mechanical properties of the applied bone plate determine the stability of the fracture site and affect the endochondral ossification process and the healing performance. In recent years, biodegradable bone plates have been used in demand for the elimination of a second surgery to remove the plate. The degradation of these plates into the body environment is commonly accompanied by alterations in the mechanical properties of the bone plate and a shift in the healing performance of the bone. In the present study, the effects of using biodegradable plates with various elastic moduli and degradation patterns, including linear and nonlinear, on the healing process are investigated. A three-dimensional finite element model of the radius bone along with a mechano-regulation theory was used to study the healing performance. Two mechanical stimuli of octahedral shear strain and interstitial fluid flow are considered as the propelling factors of healing. The results of this study indicated that increasing the bone plate's initial elastic modulus accelerates the healing process. However, by increasing the initial Young's modulus of the plate more than 100 GPa, no noticeable alteration is observed. The degradation time period of the plate was seen to be directly related to the speed of the healing process. It is shown, however, that by increasing the degradation time period to more than 8 weeks, the healing performance remains almost unchanged. The results of this work showed that the application of plates with a high enough initial elastic modulus and degradation period can prevent the healing process from decelerating.

Summary Abaloparatide increased ultradistal radius bone mineral density (BMD) in the Abaloparatide Comparator Trial in Vertebral Endpoints (ACTIVE) trial. Over the subsequent 24 months in ACTIVExtend, ultradistal radius BMD gains were maintained with alendronate. Conversely, 1/3 radius BMD remained stable during ALN treatment in ACTIVExtend after decreasing during ACTIVE. Introduction Abaloparatide (ABL) increased femoral neck, total hip, and lumbar spine bone mineral density (BMD) in postmenopausal women with osteoporosis and decreased the risk of vertebral and nonvertebral fractures in ACTIVE. Effects on fracture risk and BMD were maintained subsequently with alendronate (ALN) in ACTIVExtend. In a prespecified subanalysis of ACTIVE, ABL also increased BMD at the ultradistal radius. Our objective was to determine the efficacy of ABL followed by ALN vs placebo (PBO) followed by ALN on forearm BMD and fracture risk over 43 months in ACTIVExtend. Methods Ultradistal and 1/3 radius BMD (ACTIVE baseline to month 43) were measured (ABL/ALN, n = 213; PBO/ALN, n = 233). Wrist fracture rates were estimated for the ACTIVExtend intent-to-treat population (ABL/ALN, n = 558; PBO/ALN, n = 581) by Kaplan-Meier (KM) method. Results At cumulative month 25, mean increase from ACTIVE baseline in ultradistal radius BMD was 1.1% (standard error, 0.49%) with ABL/ALN vs − 0.8% (0.43%) with PBO/ALN (P

This study aimed to evaluate the efficacy of fractal analysis of hand-wrist radiography in the decision of conventional or surgery-assisted rapid palatal expansion (RPE).The study included 48 patients who underwent the RPE procedure. Study groups were as follows: group 1 (successful conventional RPE [n = 24, 5 male and 19 female patients; mean age ± standard deviation, 15.85 ± 0.97 years]) and group 2 (failed conventional RPE [n = 24, 5 male and 19 female patients; mean age ± standard deviation, 15.96 ± 1.08 years]). Fractal dimension (FD) analysis was conducted on hand-wrist radiographs of the patients for 4 different regions: the epiphysis-diaphysis line of the radius bone and the proximal, medial (MP3), and distal (DP3) phalanxes of the middle finger. A Student t test was performed to compare fractal values between the groups. A receiver operating characteristic analysis was applied to determine the optimal cutoff value of FDs. In addition, a Pearson correlation coefficient was calculated to evaluate the relationship between the fractal values and either age or hand-wrist stage in a second sample group (n = 90; age range, 8.7-18.7 years).Fractal values of the radius, MP3, and DP3 were significantly increased in the failed conventional RPE group (P 0.05). The optimal cutoff value of the FD for predicting the success of conventional RPE was 1.16 in the radius, 1.18 in proximal phalanxes, 1.29 in MP3, and 1.08 in DP3. There was a positive correlation between fractal values of the radius and age or hand-wrist stages (P 0.05).Within the limits of this study, results revealed that fractal analysis of hand-wrist radiographs might be considered a significant tool in the prediction of RPE success.

Context The ultradistal (UD) radius is rich in trabecular bone and is easily measured by dual energy X-ray absorptiometry (DXA). UD radius areal bone mineral density (aBMD) may help identify trabecular bone deficits, but reference data are needed for research and clinical interpretation of this measure. Objective We developed age-, sex-, and population ancestry-specific reference ranges for UD radius aBMD assessed by DXA and calculated Z-scores. We examined tracking of UD radius aBMD Z-scores over 6 years and determined associations between UD radius aBMD Z-scores and other bone measures by DXA and peripheral quantitative computed tomography. Design Multicenter longitudinal study. Participants A total of 2014 (922 males, 22% African American) children ages 5 to 19 years at enrollment who participated in the Bone Mineral Density in Childhood Study. Main Outcome Measure UD radius aBMD. Results UD radius aBMD increased nonlinearly with age (P Conclusion UD radius aBMD Z-scores strongly associated with distal radius trabecular bone density, with marginal confounding by stature. These reference data may provide a valuable resource for bone health assessment in children.

Purpose The most challenging scaphoid nonunion is the unstable nonunion with humpbacked collapse coupled with an avascular proximal pole. Dorsal distal radius pedicled vascularized bone grafts (VBGs) are contraindicated in cases of humpback deformity. The free medial femoral condyle VBG is an excellent option but it is an extensive microsurgical procedure with lengthy operative times and dual-limb incisions. In search of a local, volar, vascularized source of bone to treat this challenging subset of scaphoid nonunions, we analyzed our results with a volar distal radius bone graft based on the pedicled palmar radiocarpal artery (PRCA). Methods A prospective cohort of 15 unstable nonunions with avascular proximal pole fragments was treated with the PRCA graft and open reduction internal fixation. Preoperative carpal indices revealed a high degree of instability. All 15 lacked punctate bleeding from the proximal pole. All 15 patients were treated with the PRCA VBG technique and scanned with computed tomography at approximately 6 and 12 weeks to assess for interval healing. Results All nonunions healed with an average cross-sectional trabeculation score of 70% at week 6 and 84% at week 12. Sagittal intrascaphoid angles improved from 50° to 27°, radiolunate angle improved from –20° to –7°, scapholunate angle improved from 86° to 64°, and revised carpal height ratio improved from 1.45 to 1.53, indicating correction of the humpback collapse deformity. Patients were observed an average of 22 months to have no sign of further avascular necrosis. Conclusions Pedicled PRCA–VBG successfully addresses the dual needs of the humpbacked scaphoid nonunion with an avascular proximal pole while simultaneously limiting dissection to one limb and avoiding the additional complexities of free tissue transfer. Type of study/level of evidence Therapeutic II.

High-resolution peripheral quantitative computed tomography (HR-pQCT) devices can scan extremities at bone microstructural level in vivo and are used mainly in research of bone diseases. Two HR-pQCT scanners are commercially available to date: XtremeCT (first generation) and XtremeCT-II (second generation) from Scanco Medical AG (Switzerland). Recently, we have proposed an adaptive local thresholding (AT) technique and showed that it can improve quantification accuracy of bone microstructural parameters, with visually less sharp cone-beam CT (CBCT) images providing a similar accuracy than XtremeCT. The aim of this study was to evaluate whether the AT segmentation technique could enhance the accuracy of HR-pQCT in quantifying bone microstructural images and to assess whether the agreement between XtremeCT and XtremeCT-II could be improved. Nineteen radii were scanned with three scanners from Scanco Medical AG: (1) XtremeCT at 82 μm, (2) XtremeCT-II at 60.7 μm and (3) the small animal microCT scanner VivaCT40 at 19 μm voxel size. The scans were segmented applying two different methods, once following the manufacturer standard technique (ST), and once by means of AT. Three-dimensional (3D) morphological analysis was performed on the trabecular volume of the segmented images using the manufacturer's standard software to calculate bone volume fraction (BV/TV), trabecular thickness (Tb.Th), separation (Tb.Sp) and number (Tb.N). The average accuracy of XtremeCT improved from R2 = 0.76 (ST) to 0.85 (AT) and reached the same level of accuracy as XtremeCT-II with ST (R2 = 0.86). The largest improvements were obtained for BV/TV and Tb.Th. For XtremeCT-II, mean accuracy improved slightly from R2 = 0.86 (ST) to 0.89 (AT). For both segmentations and both scanners, the standard section was quantified slightly more accurate than the subchondral section. The agreement between the scanners was enhanced from R2 = 0.89 (ST) to 0.98 (AT). In conclusion, AT can enhance the accuracy of XtremeCT to quantify distal radius bone microstructural parameters close to XtremeCT-II level and increases the agreement between the two HR-pQCT scanners. High-resolution peripheral quantitative computed tomography, segmentation, bone microstructural parameters. ispartof: BONE vol:154 ispartof: location:United States status: published

Objective Patients with rheumatoid arthritis (RA) are almost twice as likely to develop cardiovascular disease (CVD) as those without. However, traditional CVD risks have been shown to underperform in RA patients; thus, we aimed to identify new surrogate risk factors to better reflect their atherosclerotic burden. Methods A total of 380 RA patients with carotid atherosclerosis data were analyzed in this prospective cohort study. The primary outcome was carotid plaque progression over the 3-year follow-up period. Risk parameters assessed for the progression of carotid plaque were categorized as demographics, traditional CVD risks, RA-related risks, and bone parameters. Results The progression of carotid plaque was associated with the level of rheumatoid factor (p = 0.025), serum C-terminal telopeptide of type-I collagen (CTX-I) (p = 0.014), and femur and distal radius bone mass density (BMD) (p = 0.007 and 0.004, respectively), as well as traditional CVD risk factors. In multivariable analyses, the bone parameters of serum CTX-I and distal radius BMD proved to be independent predictors of the progression of carotid plaque along with hyperlipidemia, smoking, and baseline carotid plaque (all, p Conclusion High serum CTX-I and lower radius BMD, reflecting high bone turnover, were independent risk factors for the progression of carotid plaque in RA patients, implicating the direct or indirect role of bone metabolism on the atherosclerotic burden.

Off-axis loading associated with a fall onto the outstretched hand has been hypothesized to induce distal radius failure at lower magnitudes than axially directed loading commonly used in biomechanical models for estimating fracture risk. However, this hypothesis has not been tested with side-to-side experimental testing. The objective of this study was to compare distal radius failure loads between forearm pairs experimentally tested in an axial or off-axis loading configuration. We acquired 18 pairs of cadaveric forearms from 18 female donors (mean age (standard deviation): 84.4 (7.9) years). Each forearm pair was tested to failure using either an axial compression test (vertical orientation with 0° dorsal inclination, 3°-6° radial inclination) or an off-axis test corresponding to the hand position during a fall (15° dorsal inclination, 3°-6° radial inclination). Failure testing was performed at 3 mm/s onto the palm of the hand until fracture occurred. Of the 18 pairs, 11 sustained a distal radius fracture. We compared failure loads between the two groups using a paired t test. Results indicated that failure load under off-axis loading was 29% lower than failure load under axial compressive loading (mean difference: -0.31 kN; 95% confidence interval: -0.47 to -0.16 kN, P = .001). In conclusion, off-axis loading associated with a fall onto the outstretched hand resulted in a 29% lower failure load. Integrating an off-axis loading configuration into current biomechanical models of distal radius bone strength may prevent overestimating of failure load and may offer a clinically relevant option to estimate distal radius fracture risk and monitor therapy efficacy.

Background Distal radius is third most common site for occurrence of Giant cell tumor (GCT) of bone. Most of Campanacci grade II & III cases require resection. Reconstructions of these defect are challenging. Though fibular arthroplasty provides mobility at wrist but is fraught with complications of donor site morbidity and instability with wrist pain. Wrist arthrodesis with ulna translocation provides stable reconstruction but is cosmetically less appealing. We present a series of 12 cases of GCT of distal radius treated with short segment (6 cm or less) resections and wrist fusion with iliac crest grafting. We evaluated donor site morbidity, functional and oncological outcomes. Objectives To assess time to union, donor site morbidity, functional and oncological outcomes after wrist fusion with iliac crest bone grafting for distal radius resection (≤6 cm). Methods Retrospective analysis was performed from a prospectively maintained database between January 2011 and December 2017, 12 patients (7 male and 5 female; 9 primary and 3 recurrent; all Campanacci grade III) were included. Mean age was 29 years (15–41 years) with mean resection length of 5.1 cm (4.5–6 cm). The dominant hand was involved in 6 patients. Time to union, donor site morbidity, functional and oncologiacal outcomes were evaluated. Functional outcomes were evaluated using Musculo-Skeletal Tumor Society (MSTS) score and Patient Rated Wrist Evaluation (PRWE) score. Grip strength and arc of forearm rotation were also evaluated. Results All patients were available for analysis. No symptomatic donor site morbidity was observed. One patient had prominent implant following a fall and delayed union. Mean time to union for 22 osteotomy sites in rest of 11 patients (both proximal and distal) was 6 months (4–11 months). At median follow up of 45 months (18–78 months) 2 patients had soft tissue recurrence, 1 had a stable pulmonary metastasis. Local Recurrence rate was 17%. All patients returned to their pre surgery activity. Mean MSTS score was 25 (19–29) and PRWE score was 12 (6–28). Grip strength and Prono - supination measurements were available in 10 patients. Grip strength was 69% of non operated limb. Mean supination was 53° (0° to 80°) and mean protonation was 73° (40° to 80°). Mean arc of rotation was 126° (80° to 160°). Conclusion Reconstruction of distal radius bone defects with Iliac crest bone grafting and wrist arthrodesis retains prono-supination while maintaining wrist girth (cosmesis). The oncologic and functional outcomes make it an acceptable modality in selected cases of distal radius tumours with short resection length (≤6 cm).

We determine interactive effect of a combined model of housing systems for rearing pullets and raising adult birds on bone quality. The LSL-Lite pullets were reared in either an aviary system (A) or conventional cages (C). At week 16, the birds were transferred either to the same housing type through the adult stage (A-A or C-C, for rearing and adult phase, respectively) or to enriched system (A-E or C-E, respectively). In the rearing stage, C cages housed 16 pullets/cage (week 0 to 6) and 8 pullets/cage (week 6 to 16) with a space allowance of 145 and 290 cm2/pullet, respectively; the rearing aviary housed 756 pullets/enclosure allowing 285 cm2/pullet (week 0 to 6) and 754 cm2/pullet (week 6 to 16). In the adult phase, C cages were 58.4 cm wide × 66.0 cm deep (482 cm2/pullet, 8 pullets/cage). For adult A, a commercial multi-tier aviary provided a space allowance >1000 cm2/hen system with litter area. Enriched system housed 60 birds/cage at 750 cm2/bird with perches, nest, and scratch mat. Bone samples were collected from the adult phase (week 73) and analysed for bone quality indices including bone breaking strength (BBS), total bone weight (TBW), ash content of the medullary (femur and tibia), pneumatic (humerus and keel), and radius bones. The A-A hens had the greatest (P

In this study, the potential of vascularized tissue-engineered bone constructed by a double cell-sheet (DCS) complex and polylysine (PLL)-modified coralline hydroxyapatite (CHA) to repair large radius bone defects was investigated in rabbits. Firstly, the DCS complex was obtained after rabbit adipose-derived mesenchymal stem cell (ADSC) culture was induced. Secondly, PLL-CHA composite scaffolds with different concentrations of PLL were prepared by the soaking and vacuum freeze-drying methods, and then the scaffolds were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, compression performance testing and cytocompatibility evaluation. Thirdly, DCS-PLL-CHA vascularized tissue-engineered bone was constructed in vitro and transplanted into a large radius bone defect model in rabbits. Finally, the potential of the DCS-PLL-CHA vascularized tissue-engineered bone to repair the large bone defect was evaluated through general observations, laser speckle imaging, scanning electron microscopy (SEM), histological staining, radiography observations and RT-PCR. The in vitro experimental results showed that the DCS complex provided a very large cell reserve, which carried a large number of osteoblasts and vascular endothelial cells that were induced in vitro. When the DCS complex was combined with the PLL-CHA scaffold in vitro, the effects of PLL on cell adhesion, proliferation and differentiation led to a situation similar to the chemotaxis of the body, making the combined complex more conducive to graft cellularization than the DCS complex alone. The in vivo experiments showed blood supply on the surface of the callus in each group, and the amount of blood perfusion on the surface of the defect area was almost equal among the groups. At 12 weeks, the surface of the DCS-PLL-CHA group was completely wrapped by bone tissue and osteoids, the cortical bone image was basically continuous, and the medullary cavity was mainly perforated. A large amount of well-arranged lamellar bone was formed, a small amount of undegraded CHA exhibited a linear pattern, and a large amount of bone filling could be seen in the pores. At 12 weeks, the expression levels of BGLAP, SPP1 and VEGF were similar in each group, but PECAM1 expression was higher in the DCS-PLL-CHA group than in the autogenous bone group and CHA group. The results showed that PLL could effectively promote the adhesion, proliferation and differentiation of ADSCs and that DCS-PLL-CHA vascularized tissue-engineered bone has potential for bone regeneration and bone reconstruction and can be used to repair large bone defects. Statement of Significance 1. PLL-CHA composite scaffolds with different concentrations of PLL were prepared by the soaking and vacuum freeze-drying methods. 2. The vascularized tissue-engineered bone was constructed by the double cell sheet (DCS) complex combined with PLL-CHA scaffolds. 3. The DCS-PLL-CHA vascularized tissue-engineered bone has potential for bone regeneration and bone reconstruction and can be used to repair large bone defects.

© The Author(s) 2019. Background: Distal radius fracture reduction by internal fixation is most commonly achieved using volar locking plates (VLPs). Many standard VLP designs make little point contact with radius anatomy, and most postsurgical complications following fixation are attributed to poor implant fit. Sex differences may require consideration in implant design, as females more commonly require VLP removal. Therefore, the purpose of this research was to determine whether the relationships between measures of radius shape are proportional between the sexes. Methods: Three-dimensional radius bone geometries were created from 40 male and 34 female (mean age = 72.04 years) forearm computed tomographic scans in Mimics (Materialise NV, Leuven, Belgium). Eleven measures of radius shape were collected from each scan. Principal components analysis was performed on these measures to determine which shape variables account for the greatest differences in radius shape among individuals and between the sexes. Results: Principal component scores representing isometric radius size separated the sexes. Six anthropometric measures significantly correlated with isometric radius size for all specimens, whereas 3 and 1 measures significantly correlated with isometric radius size in males and females, respectively. Conclusions: Anthropometrics of male and female radii vary by different proportions. Using anthropometrics from both sexes to create a single implant system may not result in optimal patient fit for either sex.

Mechanical loading by muscles elicits anabolic responses from bone, thus age‐related declines in muscle strength may contribute to bone fragility in older adults. We used high‐resolution peripheral quantitative computed tomography (HR‐pQCT) to determine the association between grip strength and distal radius bone density, size, morphology, and microarchitecture, as well as bone strength estimated by micro–finite element analysis (μFEA), among older men and women. Participants included 508 men and 651 women participating in the Framingham Offspring Study with grip strength measured in 2011–2014 and HR‐pQCT scanning in 2012–2015. Separately for men and women, analysis of covariance was used to compare HR‐pQCT measures among grip strength quartiles and to test for linear trends, adjusting for age, height, weight, smoking, and physical activity. Mean age was 70 years (range, 50–95 years), and men had higher mean grip strength than the women (37 kg vs. 21 kg). Bone strength estimated by μFEA‐calculated failure load was higher with greater grip strength in both men (p

This work investigates the feasibility of estimating the parameters of an exact transverse isotropy model in cortical bone. The model describes the anisotropy of the velocity of compressional and shear bulk elastic waves. We propose to achieve this with ultrasound imaging relying on the transmission of unfocused beams and with an autofocus method. The latter is based on the principle that the reconstructed ultrasound image shows optimal quality if the velocity model is correct. The autofocus approach is applied to a composite image of the interface between cortical bone and marrow. It is obtained by incoherent summation of four types of images exploiting four different ray paths in the cortical bone layer, three of them involving mode-converted shear waves. If the parameters of the model are correct, spatial co-localization of the interface appears in the four images. As a result, intensity and sharpness in the composite image are maximal. The five parameters of the model of transverse isotropy are successfully estimated in a tube made of a bone-mimicking material. The estimates are in good agreement with resonant ultrasound spectroscopy (RUS) measurements. The tube thickness is recovered with an error smaller than 0.3%. In vivo results at the forearm of a volunteer are promising, four parameters could be estimated and are in good agreement with ex vivo RUS measurements. Moreover x-ray peripheral computed tomography corroborates the thickness of the cortical bone layer in the ultrasound image. Weak-anisotropy and exact transverse isotropy models provide very close measurements of the thickness of the tube and the radius bone. Thus, we recommend using the model of weak transverse isotropy for real-time anatomical imaging because more computationally efficient. For material characterization however, the model of exact transverse isotropy is preferred because the elastic anisotropy of cortical bone is moderate, rather than weak.

The effects of a scaffold made of polylactic acid, poly (ɛ-caprolactone) and hydroxyapatite by indirect 3D printing method with and without differentiated bone cells was tested on the regeneration of a critical radial bone defect in rat. The scaffold characterization and mechanical performance were determined by the rheology, scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, and Fourier transform infrared spectrometry. The defects were created in forty Wistar rats which were randomly divided into the untreated, autograft, scaffold cell-free, and differentiated bone cell-seeded scaffold groups (n = 10 in each group). The expression level of angiogenic and osteogenic markers, analyzed by quantitative real time-polymerase chain reaction (in vitro), significantly improved (p0.05) in the scaffold group compared to the untreated one. Radiology and computed tomography scan demonstrated a significant improvement in the cell-seeded scaffold group compared to the untreated one (p0.001). Biomechanical, histopathological, histomorphometric, and immunohistochemical investigations showed significantly better regeneration scores in the cell-seeded scaffold and autograft groups compared to the untreated group (p0.05). The cell-seeded scaffold and autograft groups did show comparable results on the 80

Due to the complicated nature, bone defects caused by various conditions have been challenging orthopaedic surgeons and related biomedical scientists for some time, and are continuing to inspire them to seek better alternatives and new solutions. To achieve their goals, animal models of bone defects for bone grafting are essential. There are several major heterotopic models for testing in vivo osteogenesis, the subcutaneous model, the intramuscular model, the intraperitoneal model, and the mesentery model. The rabbit radial model is popular because the radius bone is tubular, which allows creation of a segmental defect that enables convenient radiographic and histological evaluation. A rabbit ulnar defect is also popular, but the ulnae do not have the round shape as the radius, which creates difficulties and errors to the processes of implant preparation, implant positioning, and sample evaluation. For long bone segmental defect models, torsional testing is an appropriate and the most popular method.

PurposeIn adults with long-term HIV infection, low bone density and increased fracture risk have emerged as significant comorbidities. Our aim was to assess the association of exercise, nutrition, and medications with bone quality in adults with long-term HIV infection.MethodsForty-three adults with HIV infection were enrolled (median BMI 25.7, range 18.2-35.6kg/m2; median age 57, range 50-69years). Participants underwent ultradistal radius and tibia high-resolution peripheral quantitative CT (HR-pQCT). Questionnaires included the revised Community Healthy Activities Model Program for Seniors (CHAMPS), the Mini Nutritional Assessment (MNA) as well as medication assessments. Multivariable linear regression models were used to evaluate the association of exercise, nutritional status, tenofovir disoproxil fumarate (TDF) and protease inhibitor (PI) use with bone density and microstructure, adjusting for demographic risk factors.ResultsIn regression models, higher nutrition scores were associated with higher tibia cortical thickness (R2=0.23; β=0.03; p=0.044) and higher radius cortical BMD (R2=0.43; β=8.4; p=0.026). Higher weekly frequency of all physical activities was significantly associated with higher radius trabecular BMD (R2=0.38; β=0.96; p=0.050), higher radius trabecular number (R2=0.31; β=0.01; p=0.026), lower tibia and radius trabecular separation (tibia: R2=0.30; β=-0.003; p=0.038; radius: R2=0.35; β=-0.003; p=0.021), and higher radius bone stiffness (R2=0.45; β=0.38; p=0.047). Higher frequency of bone loading physical activities was significantly associated with higher tibia trabecular density (R2=0.44; β=4.06; p=0.036), higher tibia bone stiffness (R2=0.46; β=3.06; p=0.050), and higher tibia estimated failure load (R2=0.46; β=0.17; p=0.049). TDF used in combination with a PI was associated with lower radius trabecular BMD (R2=0.39; β=-41.2; p=0.042), lower radius trabecular number (R2=0.34; β=-0.44; p=0.009) and greater radius trabecular separation (R2=0.42; β=0.16; p=0.002), while TDF use without a PI was not associated with reduced bone quality.ConclusionsIn adults with HIV infection, malnutrition is associated with poor cortical bone quality, while reduced frequency of physical activities and specifically reduced frequency of mechanical loading activities are associated with deficient trabecular bone structure and reduced estimates of bone strength. TDF use in combination with a PI is associated with deleterious effects on trabecular bone structure.

Improvement of clinician understanding of acceptable deformity in pediatric distal radius fractures is needed.To assess how often children younger than 10 years undergo a potentially unnecessary closed reduction using procedural sedation in the emergency department for distal radial metaphyseal fracture and the associated cost implications for these reduction procedures.This retrospective cross-sectional study included 258 consecutive children younger than 10 years who presented to a single, level I, pediatric emergency department and who had a distal radius fracture with or without ulna involvement between January 1, 2016, and December 31, 2017. Reductions were deemed to be potentially unnecessary if the coronal and sagittal plane angulation of the radius bone measured less than 20° and shortening measured less than 1 cm on initial injury radiographs. Use of procedural sedation or transfer status to another facility was noted if present. Statistical analysis was performed from April 2019 to June 2019.Potentially unnecessary reduction was the primary outcome. Radiographic findings were measured to determine reduction necessity. Additional variables measured were age, sex, time in the emergency department, transfer status, required reduction procedure, use of sedation, and cost associated with care.Of the 258 participants studied, 156 (60%) were male, with a mean (SD) age of 6.7 (2.3) years. Among 142 patients (55%) who underwent closed reduction with procedural sedation in the emergency department, 38 (27%) procedures were determined to be potentially unnecessary. Review of Common Procedural Terminology charges revealed an approximately $7000 difference between the stated cost of a reduction procedure in the emergency department vs a cast application in an outpatient orthopedic clinic for distal radial metaphyseal fractures. The mean (SD) maximal angulation in either plane for fractures that underwent appropriate reduction was 30.6° (10.3°) compared with 13.9° (4.5°) for those unnecessarily reduced (P .001). Patients who were transfers from other facilities were more than twice as likely to undergo a potentially unnecessary reduction (odds ratio, 2.3; 95% CI, 1.1-5.0; P = .03).The findings suggest that improved awareness of these acceptable deformities in young children may be associated with limiting the number of children requiring reduction with sedation, improving emergency department efficiency, and substantially reducing health care costs.

Background: The management of proximal pole nonunions of scaphoid with avascular necrosis remains the most controversial of all scaphoid fracture nonunions. Various types of vascularised bone grafts have been used to hasten union. We studied the union rate, clinical and functional outcome of 1, 2 intercompartmental supraretinacular arterial bone graft (1, 2 ICSRA) and radial styloidectomy for proximal pole scaphoid nonunion with avascular necrosis. Methods: We retrospectively analysed the four year outcome of vascularised distal radius bone graft (1, 2 ICSRA) and radial styloidectomy in 20 patients treated at our institution for proximal pole scaphoid nonunion with avascular necrosis between 2010 and 2014. Majority of cases (10) presented as failure of adequate immobilization. The average time to surgery from trauma was 14 months and mean duration of follow up was 30 months. Twelve (12) cases had features of early radioscaphoid arthritis. Nonunion and avascular necrosis were confirmed in all cases with radiographs and MRI scan. We followed the technique described by Zaidemberg et al for harvesting the vascualrised bone grafting from the distal radius. Results: Majority of the cases (80%) united by 20 weeks. There was significant improvement in the grip strength and pain postoperatively. Wrist flexion-extension and radial-ulnar deviation arcs improved but was not statistically significant. The Mayo Wrist Score showed 75 percent of patients had an excellent or good outcome. The scapholunate angle also improved from 62.5 deg to 46.5 deg postoperatively. Radiographic union was achieved in sixteen cases (80%) by 20 weeks. Three cases (15%) went for delayed union and achieved bony healing by thirty weeks. One case (5%) developed pintract infecton and progressed to radioscaphoid arthritis. Conclusions: Our study highlights the efficacy of 1,2 ICSRA vascualrised distal radius bone grafting in proximal pole scaphoid nonunions with avascualr necrosis in achieving good union rate with acceptable clinical and functional outcome in this difficult problem. This procedure can be done under regional block without the need for microsurgical set up and costly implants. Vascularised distal radius grafts with radial styloidectiomy is a promising solution for scaphoid proximal nonunions with avascular and early radioscaphoid arthritic changes.

Objectives There is strong affinity between fluoride and calcium, and mineralized tissues. Investigations of fluoride and bone health during childhood and adolescence show inconsistent results. This analysis assessed associations between period-specific and cumulative fluoride intakes from birth to age 11, and age 11 cortical bone measures obtained using peripheral quantitative computed tomography (pQCT) of the radius and tibia (n = 424). Methods Participants were a cohort recruited from eight Iowa hospitals at birth. Fluoride intakes from water, other beverages, selected foods, dietary supplements, and dentifrice were recorded every 1.5-6 months using detailed questionnaires. Correlations between bone measures (cortical bone mineral content, density, area, and strength) and fluoride intake were determined in bivariate and multivariable analyses adjusting for Tanner stage, weight and height. Results The majority of associations were weak. For boys, only the positive associations between daily fluoride intakes for 0-3 years and radius and tibia bone mineral content were statistically significant. For girls, the negative correlations of recent daily fluoride intake per kg of body weight from 8.5 to 11 years with radius bone mineral content, area, and strength and tibia strength were statistically significant. No associations between cumulative daily fluoride intakes from birth to 11 years and bone measures were statistically significant. Conclusions In this cohort of 11-year-old children, mostly living in optimally fluoridated areas, life-long fluoride intakes from combined sources were weakly associated with tibia and radius cortical pQCT measures.

Background The standard treatment for osteoporosis was controversial. Denosumab and bisphosphonates were two most common drugs. The purpose of this study was to compare the efficacy and safety of denosumab with bisphosphonates to treat osteoporosis. Methods Published literatures, only including randomized controlled trials (RCTs), were searched in the following electronic databases: PubMed, Embase, Web of Science, Cochrane Library, and Google database from inception to April 20 2018. Studies that compared denosumab with bisphosphonates to treat osteoporosis were included. Random-effect model was used for meta-analysis due to the unavoidable clinical heterogeneity. We used the risk of fracture as the primary outcome. Stata 12.0 was used for meta-analysis. Results Eleven studies involving 5446 patients (denosumab = 2873, bisphosphonates = 2573) were included in the present meta-analysis. There was no significant difference between the risk of fracture (risk ratio (RR), 1.13; 95% confidence interval (CI), 0.82–1.55; P = 0.466), adverse events (AEs) (RR 1.00; 95% CI 0.96–1.04; P = 0.957) and withdrawn due to AEs (RR 0.68; 95% CI 0.34–137; P = 0.280). Denosumab compared with bisphosphonates significantly increased change in total hip, femoral neck, lumbar spine, and one-third radius bone mineral density (BMD) for postmenopausal osteoporosis patients (P

While weight-bearing and resistive exercise modestly increases aBMD, the precise relationship between physical activity and bone microstructure, and strain in humans is not known. Previously, we established a voluntary upper-extremity loading model that assigns a person's target force based on their subject-specific, continuum FE-estimated radius bone strain. Here, our purpose was to quantify the inter-individual variability in radius microstructure and FE-estimated strain explained by site-specific mechanical loading history, and to determine whether variability in strain is captured by aBMD, a clinically relevant measure of bone density and fracture risk. Seventy-two women aged 21–40 were included in this cross-sectional analysis. High resolution peripheral quantitative computed tomography (HRpQCT) was used to measure macro- and micro-structure in the distal radius. Mean energy equivalent strain in the distal radius was calculated from continuum finite element models generated from clinical resolution CT images of the forearm. Areal BMD was used in a nonlinear regression model to predict FE strain. Hierarchical linear regression models were used to assess the predictive capability of intrinsic (age, height) and modifiable (body mass, grip strength, physical activity) predictors. Fifty-one percent of the variability in FE bone strain was explained by its relationship with aBMD, with higher density predicting lower strains. Age and height explained up to 31.6% of the variance in microstructural parameters. Body mass explained 9.1% and 10.0% of the variance in aBMD and bone strain, respectively, with higher body mass indicative of greater density. Overall, results suggest that meaningful differences in bone structure and strain can be predicted by subject characteristics., Highlights • Areal bone mineral density (aBMD) explains 51% of the variability in bone strain. • Adult bone loading predicts greater cortical porosity and trabecular density. • Greater body mass predicts greater aBMD and lower bone strain.

Objectives: As clinics that treat patients with osteoporosis do not usually have central dual-energy X-ray absorptiometry (DXA), bone density is often measured with radial DXA. However, no long-term evidence exists for radius bone density outcomes following treatment with once-weekly teriparatide in actual medical treatment. Methods: We evaluated changes in bone density at 6-, 12-, and 18-month intervals using radial DXA in patients treated with once-weekly teriparatide for more than 6 months. Results: A significant increase in bone mineral density (BMD) was observed at the 1/3 and 1/10 radius sites 12 months after the initiation of once-weekly teriparatide. We also observed that the rate of change in BMD was greater at the distal 1/10 radius than at the 1/3 radius. Conclusions: Considering these points, the effect of once-weekly teriparatide therapy can be observed at the radius. In clinics that do not have central DXA, but instead have radial DXA, these findings can help to evaluate the effect of once-weekly teriparatide treatment on osteoporosis. Keywords: Once-weekly teriparatide, Osteoporosis, Radius, Dual-energy X-ray absorptiometry

Although peripheral DXA is not recommended for the diagnosis of osteoporosis or to monitor osteoporotic treatments, its use for fracture risk assessment is supported by several studies. In addition, its potential interest is supported by the recent demonstration, in prospective cohorts, of the contribution of distal radius microstructure and strength, assessed by high-resolution peripheral QCT (HRpQCT), to predict incident fractures beyond the classical clinical tools (femoral neck BMD and FRAX). Indeed, areal BMD measured by DXA at the ultra-distal radius is highly correlated with bone strength derived from HRpQCT measurements at the same site. Ultra-distal radius areal BMD is therefore highly associated with fracture risk, with associations of higher magnitude than at the “classically recommended” one-third distal radius. Furthermore, ultra-distal radius areal BMD is also associated with incident fractures in non-osteoporotic women in women with T-score > –2.5 SD on hip and spine DXA or women with FRAX score below the intervention threshold for age. Since more than half of low-trauma fractures occur in individuals not identified as being at high risk by BMD testing at the spine or hip, radius bone mineral density may help to refine fracture risk in patients with osteopenia defined by central DXA (spine or hip), or relatively few clinical risk factors.

44è congrès de la Société de Biomécanique, POITIERS, FRANCE, 28-/10/2019 - 30/10/2019; Fragility fractures of bones are a worldwide health problem. Actual gold standard methods to assess bone fragility have shown to be insufficient (Siris et al. 2004; Chapurlat 2013). Finite elements models (FEM) have been proposed to evaluate bone strength. Most of the previous studies used a static axial loading to assess bone strength. However, among fractures due to a fall from the standing height, only 15% are related to an axial loading (Melton et al. 2010) and the velocity can reach 2 m/s (Tan et al. 2006). Thus, we assume that this dynamic loading should be considered. The main aim of our study is to develop and validate a finite elements model to predict radius bone strain under loading conditions simulating a fall. To reach this goal a first step consisted in developing an ex-vivo protocol to reproduce a forward fall leading to fractured and non-fractured bones (already published) and now comparing experimental surface strains of the distal radius with a specimen-specific finite element model.

Obese adolescents have increased fracture risk, but effects of alterations in adiposity on bone accrual and strength in obese adolescents are not understood. We evaluated 12-month changes in trabecular and cortical volumetric bone mineral density (vBMD) and cortical geometry in obese adolescents undergoing a randomized weight management program, and investigated the effect of body composition changes on bone outcomes. Peripheral quantitative computed tomography (pQCT) of the radius and tibia, and whole-body dual-energy X-ray absorptiometry (DXA) scans were obtained at baseline, 6 months, and 12 months in 91 obese adolescents randomized to standard care versus behavioral intervention for weight loss. Longitudinal models assessed effects of body composition changes on bone outcomes, adjusted for age, bone length, and African-American ancestry, and stratified by sex. Secondary analyses included adjustment for physical activity, maturation, vitamin D, and inflammatory biomarkers. Baseline body mass index (BMI) was similar between intervention groups. Twelve-month change in BMI in the standard care group was 1.0 kg/m2 versus -0.4 kg/m2 in the behavioral intervention group (p < 0.01). Intervention groups were similar in bone outcomes, so they were combined for subsequent analyses. For the tibia, BMI change was not associated with change in vBMD or structure. Greater baseline lean body mass index (LBMI) associated with higher cortical vBMD in males, trabecular vBMD in females, and polar section modulus (pZ) and periosteal circumference (Peri-C) in both sexes. In females, change in LBMI positively associated with gains in pZ and Peri-C. Baseline visceral adipose tissue (VFAT) was inversely associated with pZ in males and cortical vBMD in females. Change in VFAT did not affect bone outcomes. For the radius, BMI and LBMI changes positively associated with pZ in males. Thus, in obese adolescents, weight loss intervention with modest changes in BMI was not detrimental to radius or tibia bone strength, and changes in lean, but not adiposity, measures were beneficial to bone development. © 2017 American Society for Bone and Mineral Research.

We recently reported impaired bone strength in girls with low- to moderate-energy distal radius fractures (Fx) compared with girls with no history of forearm fractures (Non-Fx). We aimed to determine whether bone strength deficits observed at baseline were still present after 2 years. We assessed bone strength, microarchitecture, and bone mineral density (BMD) of the non-fractured (Fx) and non-dominant (Non-Fx) distal radius (7% site) at baseline, 12, and 24 months using high-resolution pQCT (Scanco Medical, Bruttisellen, Switzerland) in 104 girls (aged 11.0 ± 1.7 years; 47 Fx, 57 Non-Fx) and 157 boys (aged 12.7 ± 1.7 years; 86 Fx, 71 Non-Fx). Bone outcomes included total area (Tt.Ar) and bone mineral density (Tt.BMD), trabecular bone volume ratio (BV/TV), thickness (Tb.Th), separation (Tb.Sp), and number (Tb.N), and cortical BMD (Ct.BMD), thickness (Ct.Th), and porosity (Ct.Po). We used finite element analysis to estimate bone strength (failure load [F.Load]; ultimate stress [U.Stress]; load-to-strength ratio). We used sex-specific mixed-effects models to compare bone outcomes between Fx and Non-Fx over 2 years. In girls, those with fractures had 18% to 24% lower U.Stress and 5% to 9% lower Tt.BMD than Non-Fx at all time points (p < 0.017). In secondary analysis by fracture degree, girls with low-energy (LE) fractures had 19% to 21% lower F.Load, 25% to 47% lower U.Stress, 11% to 14% lower Tt.BMD, and 11% to 15% lower BV/TV than Non-Fx at all time points (p < 0.017). In contrast, boys' bone outcomes were similar between Fx and Non-Fx at all time points. In secondary analysis by fracture degree, boys with LE fractures had 10% lower Tt.BMD and 10% lower Ct.Th compared with Non-Fx at 12 months only. Deficits in distal radius bone strength and trabecular bone microarchitecture appear to track across 2 years after a forearm fracture in girls but not in boys. Longer follow-up is needed to determine whether deficits persist into adulthood in women and how they may influence future risk of fragility fracture. © 2017 American Society for Bone and Mineral Research.

Microarc oxidation (MAO) coated magnesium (Mg) with improved corrosion resistance appeal increasing interests as a revolutionary biodegradable metal for fractured bone fixing implants application. However, the in vivo corrosion degradation of the implants and bone healing response are not well understood, which is highly required in clinic. In the present work, 10μm and 20μm thick biocompatible MAO coatings mainly composed of MgO, Mg2SiO4, CaSiO3 and Mg3(PO4)2 phases were fabricated on AZ31 magnesium alloy. The electrochemical tests indicated an improved corrosion resistance of magnesium by the MAO coatings. The 10μm and 20μm coated and uncoated magnesium plates were separately implanted into the radius bone fracture site of adult New Zealand white rabbits using a 3mm width bone fracture defect model to investigate the magnesium implants degradation and uninhibited bone healing. Taking advantage of the good biocompatibility of the MAO coatings, no adverse effects were detected through the blood test and histological examination. The implantation groups of coated and uncoated magnesium plates were both observed the promoting effect of bone fracture healing compared with the simple fracture group without implant. The releasing Mg2+ by the degradation of implants into the fracture site improved the bone fracture healing, which is attributed to the magnesium promoting CGRP-mediated osteogenic differentiation. Mg degradation and bone fracture healing promoting must be tailored by microarc oxidation coating with different thickness for potential clinic application.

Objectives: We aimed to evaluate the safety and outcomes of plate-screw fixation used for the immediate treatment of type-IIIC open fractures of forearm bones with complex soft tissue injuries. Methods: A total of 22 patients (mean age: 31.6, range: 24-60) treated between 2004-2010 were retrospectively analyzed. All injuries resulted from high-energy traumas and fractures were classified using AO classification. All patients had vascular and nerve injuries, and four had skin defects associated with double fractures of the forearm. All patients were operated on within the first eight hours following injury. Six patients with comminuted fractures or with bone defects underwent primary bone grafting, and one patient was treated with shortening. Primary skin closure was achieved in 17 patients and three patients underwent immediate repair using skin grafts, while two patients were repaired with immediate transposition flaps. Bony unions, complications, and functional results via a DASH questionnaire were investigated. Results: Mean follow-up was 28 months (range: 14-70). In all patients, radius bone union was achieved. Two patients underwent a Sauve-Kapandji procedure, utilizing the fractured segment of the ulnar diaphysis as a graft for radius. In one patient, osteosynthesis was repeated after 6 months because of nonunion. Mean period to bony union was 4.59 months (range: 3-6). Superficial infection developed in three patients after the operation, and was resolved with antibiotic therapy. The mean DASH score after surgery was 25.6. Conclusion: In high nergy traumas of the upper extremity associated with complex injuries and Type-IIIC forearm fractures, severity of soft tissue injuries determined the functional results in patients, demonstrating it is possible to achieve a safe and efficient fixation with immediate plate-screw osteosynthesis. [Hand Microsurg 2017; 6(1.000): 1-8]

Made available in DSpace on 2021-06-25T10:36:15Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-01-01 Background: Malignant peripheral nerve sheath tumors are neurogenic neoplasms that originate from cells that surround the axons of peripheral nerves. Surgery is the treatment of choice for peripheral nerve sheath tumors. They have a better prognosis when the lesion is in the extremity of a limb and the surgeon leaves wide peripheral margins after resection. However, this procedure makes local treatment a challenge due to difficult wound healing in this region. This report describes a successful case involving the use of a meshed skin graft immediately after resection of a neurofibrosarcoma in the distal region of the radius bone of a dog. Case: A 6-year-old Boxer bitch weighing 40 kg was admitted with a history of a round, firm, non-ulcerated skin nodule attached to the lateral side of the distal region of the right radius bone, which had been present for about 40 days. Fine needle aspiration cytology of the lesion showed the presence of mesenchymal cells, suggesting a sarcoma. Thus, the decision was made for an incisional biopsy to confirm the diagnosis and for the preparation of a subdermal pattern tubular flap for subsequent rotation and transposition to close the wound that would be formed after the complete removal of the lesion. After the 7th postoperative day, the diagnosis of low-grade neurofibrosarcoma was confirmed and due to the presence of necrotic onset in the middle portion of the tubular flap, further surgical intervention was scheduled for the resection of the tube flap, en bloc removal of the neoplastic lesion with peripheral margins of 2 cm, and wound closure with a free skin graft. A mesh skin graft was made with a portion of the right flank skin. The mesh graft was carefully implanted on the recipient bed using simple interrupted sutures with a 3-0 non-absorbable monofilament suture material. A dressing made with water-based sterile lubricating solution and gauze and a modified Robert Jones bandage were applied. The patient was treated with analgesic medication, antimicrobial therapy, and gastric protectors. The first bandage and dressing were changed after 48 h, and only warm physiological solution was used. Histopathological analysis confirmed the diagnosis of low-grade neurofibrosarcoma with free surgical margins. The dressing was changed every 72 h for up to 12 postoperative days, when the immobilization was removed, and wound cleaning could be completed at home using physiological solution and a dressing with nitrofurazone ointment. Granulation tissue was first seen at day 12, and at day 30 the wound was completely closed. Discussion: The primary closure of skin defects after the resection of tumors located in the distal portion of limbs is often not possible due to a lack of adjacent skin. Thus, grafts are commonly used to repair the skin in these areas using the technique presented in this report. In order to survive, skin grafts need a vascular bed capable of allowing new blood vessel connections with the implanted skin portion. There is no consensus in the literature on the best bed for graft implantations. In the case described in this study, a free mesh graft was implanted on a fresh wound without granulation tissue, which resulted in excellent clinical evolution and total survival of the graft. Excellent clinical results were achieved with the graft, since its survival and adherence to the recipient bed occurred without complications. The clinical result of this case suggests that the application of full-thickness mesh grafts to fresh wounds in distal limbs immediately after tumor resection is a good alternative when the surgical wound is too large (which prevents primary closure). Good preoperative planning associated with good surgical techniques and adequate postoperative management are essential for the success of the technique under these conditions. M.V. Autônomo Programa de Pós-Graduação em Cirurgia Veterinária Faculdade de Ciências Agrária e Veterinárias (FCAV) Universidade Estadual Paulista (UNESP) Departamento de Clínica e Cirurgia da FCAV-UNESP Programa de Pós-Graduação em Cirurgia Veterinária Faculdade de Ciências Agrária e Veterinárias (FCAV) Universidade Estadual Paulista (UNESP) Departamento de Clínica e Cirurgia da FCAV-UNESP