Glycative stress inhibits hypertrophy and impairs cell membrane integrity in overloaded mouse skeletal muscle.

BACKGROUND: Glycative stress, characterized by the formation and accumulation of advanced glycation end products (AGEs) associated with protein glycation reactions, has been implicated in inducing a decline of muscle function. Although the inverse correlation between glycative stress and muscle mass and strength has been demonstrated, the underlying molecular mechanisms are not fully understood. This study aimed to elucidate how glycative stress affects the skeletal muscle, particularly the adaptive muscle response to hypertrophic stimuli and its molecular mechanism. METHODS: Male C57BL/6NCr mice were randomly divided into the following two groups: the bovine serum albumin (BSA)-treated and AGE-treated groups. Mice in the AGE-treated group were intraperitoneally administered AGEs (0.5 mg/g) once daily, whereas those in the BSA-treated group received an equal amount of BSA (0.5 mg/g) as the vehicle control. After 7 days of continuous administration, the right leg plantaris muscle of mice in each group underwent functional overload treatment by synergist ablation for 7 days to induce muscle hypertrophy. In in vitro studies, cultured C2C12 myocytes were treated with AGEs (1 mg/mL) to examine cell adhesion and cell membrane permeability. RESULTS: Continuous AGE administration increased the levels of fluorescent AGEs, Nε-(carboxymethyl) lysine, and methylglyoxal-derived hydroimidazolone-1 in both plasma and skeletal muscle. Plantaris muscle weight, muscle fibre cross-sectional area, protein synthesis rate, and the number of myonuclei increased with functional overload in both groups; however, the increase was significantly reduced by AGE treatment. Some muscles of AGE-treated mice were destroyed by functional overload. Proteomic analysis was performed to explore the mechanisms of muscle hypertrophy suppression and myofibre destruction by AGEs. When principal component analysis was performed on 4659 data obtained by proteomic analysis, AGE treatment was observed to affect protein expression only in functionally overloaded muscles. Enrichment analysis of the 436 proteins extracted using the K-means method further identified a group of proteins involved in cell adhesion. Consistent with this finding, dystrophin-glycoprotein complex proteins and cell adhesion-related proteins were confirmed to increase with functional overload; however, this was attenuated by AGE treatment. Additionally, the treatment of C2C12 muscle cells with AGEs inhibited their ability to adhere and increased cell membrane permeability. CONCLUSIONS: This study indicates that glycative stress may be a novel pathogenic factor in skeletal muscle dysfunctions by causing loss of membrane integrity and preventing muscle mass gain.

Is a Novel Fluoroscopic Intraoperative Reference System Superior to Conventional Management for Distal Radius Fracture Reduction? A Propensity-matched Comparative Study.

BACKGROUND: Preoperative planning is generally performed to simulate the process of reduction as well as to determine the size and placement of implants in patients undergoing distal radius fracture surgery. We previously described a three-dimensional (3D) digital preoperative planning system for the osteosynthesis of distal radius fractures, and we have developed a novel intraoperative referencing system that superimposes preoperative planning (such as plate position and length) onto fluoroscopic images during surgery; however, its efficacy has not been evaluated compared with conventional planning and surgery. QUESTIONS/PURPOSES: Does use of a novel intraoperative referencing system result in (1) better Mayo wrist scores at 3 and 6 months after surgery and (2) less loss of reduction in terms of ulnar variance, palmar tilt, and radial inclination on plain radiographs taken 1 week, 3 months, and 6 months after surgery compared with conventional preoperative planning? METHODS: Between April 2014 and October 2021, we treated 294 patients with open reduction and volar plate fixation for distal radius fractures. Of 294 patients, 65% (191) underwent surgery using either conventional preoperative planning or a novel intraoperative referencing system. The remaining patients were excluded because they were younger than 18 years, they had some missing medical records related to the clinical outcomes, or they had a previous history of upper extremity injuries. During that time, we generally treated fractures with volar plates when there was: more than 2 mm of stepoff/gap in the articular surface, a dorsal tilt more than 15°, radial inclination less than 15°, or radial shortening more than 5 mm. Generally, we used a flexor carpi radialis approach. In some patients who had dorsal fragments, we added a dorsal approach. At that time, we were developing the new intraoperative referencing system, so it was not used consistently. To arrive at a fair assessment, we opted to perform propensity matching based on age, gender, and AO fracture type. During the period in question, 36% (69 of 191) of patients with distal radius fractures who received a volar plate were treated using our novel intraoperative referencing system, and 64% (122 of 191) had surgery using conventional preoperative planning (control group). Of those, 91% (63 of 69) of patients who were treated with the intraoperative referencing system and 89% (108 of 122) of those in the control group were available for follow-up with all imaging and Mayo wrist scores at least 6 months after surgery. After propensity matching, that left us with two groups of 39 patients, who were well matched in terms of age and fracture type; these were the study groups. We also tried to match them according to gender, but there were fewer patients in the intraoperative referencing group, and the percentage of women for each group differed: 70% (44 of 63) in the intraoperative referencing group and 76% (82 of 108) in the control group. Also, there were fewer men with C3 fractures in the control group. Therefore, 64% (25 of 39) of patients in the intraoperative referencing group were women and 77% (30 of 39) of patients in the control group were women. In the intraoperative referencing group, our novel intraoperative referencing system was used in combination with the 3D digital preoperative planning system for preoperative planning. In the control group, preoperative planning was performed manually in a conventional manner using tracing paper and implant templates or using a digital template. We compared the groups in terms of operative duration, the radiation dose used in surgery, and Mayo wrist scores at 3 and 6 months after surgery. We also compared the groups in terms of loss of reduction on ulnar variance, palmar tilt, and radial inclination on plain radiographs taken 3 months and 6 months after surgery. We considered the plain radiograph taken 1 week after surgery as a baseline. Each item was compared between the image fusion and control groups using a Welch t - test. RESULTS: Mayo wrist scores were no different between the intraoperative referencing system and the control group at 3 months (71 ± 7 versus 72 ± 11, mean difference 1 [95% CI -3.7 to 5.7]; p = 0.07) or at 6 months after surgery (76 ± 6 versus 79 ± 11, mean difference 3 [95% CI -3.5 to 7.9]; p = 0.12). There were no differences in surgical duration or radiation doses between the intraoperative referencing and control groups. We found only a small advantage in favor of the intraoperative referencing system in terms of loss of reduction on ulnar variance (3 months after surgery: 0.2 ± 0.4 mm versus 0.6 ± 0.7 mm, mean difference 0.4 mm [95% CI 0.15 to 0.69]; p = 0.003, 6 months after surgery: 0.4 ± 0.6 mm versus 0.8 ± 0.8 mm, mean difference 0.4 mm [95% CI 0.05 to 0.73]; p = 0.02 for the intraoperative referencing system and the control group, respectively). This difference in radial shortening was so small that it was not likely to have been clinically important. CONCLUSION: We found no clinically important advantages from the use of our novel intraoperative referencing system except a slight improvement in ulnar variance. Therefore, we recommend against its use in everyday practice at this time. However, future improvements may lead to better clinical outcomes, so we plan further investigations. LEVEL OF EVIDENCE: Level III, therapeutic study.

Magnetic resonance imaging predicts outcomes of conservative treatment in patients with lateral epicondylitis.

BACKGROUND: The clinical validity of positive magnetic resonance imaging findings in lateral epicondylitis is controversial. We hypothesized that magnetic resonance imaging could predict the outcome of conservative treatment. This study determined the relationship between magnetic resonance imaging-defined disease severity and treatment outcomes in patients with lateral epicondylitis. METHODS: This retrospective single-cohort study included 43 conservatively managed and 50 surgically treated patients with lateral epicondylitis. The magnetic resonance imaging scores and clinical outcomes were examined six months post-treatment, and the former was compared between patients with good and poor treatment outcomes. We developed operating characteristic curves of magnetic resonance imaging scores for treatment outcomes, and divided patients into magnetic resonance imaging-mild and severe groups according to the obtained cut-off value of the scores. We compared the outcomes of conservative treatment with that of surgery for each magnetic resonance imaging severity. RESULTS: Twenty-nine (67.4%) conservatively treated patients had good outcomes, while 14 (32.6%) had poor outcomes. The magnetic resonance imaging score was higher in patients with poor outcomes; the cut-off value was 6. Forty-three (86.0%) surgically treated patients had good outcomes, while 7 (14.0%) had poor outcomes. There was no significant difference in magnetic resonance imaging scores between patients with good and poor surgical outcomes. In the magnetic resonance imaging-mild group (score ≤ 5), the outcome showed no significant difference between the conservative and surgical treatment groups. In the magnetic resonance imaging-severe group (score≥6), the outcome of conservative treatment was significantly worse than that of surgical treatment. CONCLUSIONS: The magnetic resonance imaging score was associated with conservative treatment outcomes. A treatment strategy that includes surgery should be considered for patients with severe magnetic resonance imaging findings; this is not recommended for those with mild magnetic resonance imaging findings. Magnetic resonance imaging is helpful in determining the best treatment strategies for patients with lateral epicondylitis. LEVEL OF EVIDENCE: III, Retrospective cohort study.

Correlations between 3D preoperative planning and postoperative reduction in the osteosynthesis of distal humeral fractures.

BACKGROUND: Three-dimensional preoperative planning has been applied to the osteosynthesis of distal humerus fractures. The present study investigated the correlations between 3D preoperative planning and postoperative reduction for the osteosynthesis of distal humerus fractures using 3D parameters. METHODS: Twenty-three elbows of 23 distal humerus fracture patients who underwent osteosynthesis with three-dimensional preoperative planning were evaluated. 3D images of the distal humerus were created after taking preoperative CT scans of the injured elbow. Fracture reduction, implant selection, and placement simulations were performed based on 3D images. Postoperative CT images were taken 1 month after surgery. Correlations were evaluated with preoperative plans and postoperative 3D images. The longitudinal axis and coordinates of the humerus were defined on the 3D images. The coronal angle (CA) was defined as the angle formed by the long axis and the line connecting the medial and lateral margins of the trochlea of the humerus on a coronal plane image. The sagittal angle (SA) was defined as the angle formed by the long axis and the line connecting the top of the lateral epicondyle and the center of the humeral capitellum on a sagittal plane image. The axial angle (AA) was defined as the angle between the sagittal plane and the line connecting the medial and lateral margins behind the trochlea of the humerus. The intraclass correlation coefficients (ICC) of each measurement value were assessed between preoperative planning and postoperative images. RESULTS: Preoperative planning and postoperative measurement values were CA: 85.6 ± 5.9°/85.8 ± 5.9°, SA: 140.9 ± 8.5°/139.4 ± 7.9°, and AA: 84.0 ± 3.1°/82.6 ± 4.9°, respectively. ICCs were CA: 0.75 (P < 0.01), SA: 0.78 (P < 0.01), and AA: 0.34 (P < 0.05), respectively. CONCLUSIONS: The 3D preoperative planning of distal humeral fractures achieved the good correlations of coronal and sagittal angles, but the relatively poor correlation of the axial angle. This may be attributed to an inability to assess the rotation angle during surgery. We propose the measurement indices shown in the present study as a three-dimensional evaluation index for distal humerus fractures. TRIAL REGISTRATION: Registered as NCT04349319 at ClinicalTrials.gov.

The effects of cloth face masks on cardiorespiratory responses and VO2 during maximal incremental running protocol among apparently healthy men.

We aimed to determine the effects of wearing a cloth face mask on cardiorespiratory response, peak oxygen uptake (Vo2), respiratory muscle effort, and exercise tolerance during incremental exercise. The study had a randomized crossover design: 11 apparently healthy young men performed the Bruce protocol treadmill test in two conditions, wearing a cloth face mask (CFM) and without CFM (CON), in random order. Minute ventilation and oxygen uptake were measured using a mass spectrometry metabolic analyzer; cardiac output (CO) was measured using an impedance CO monitor; and mouth pressure (Pm) was measured and calculated as an integral Pm to assess respiratory muscle effort. Maximal minute ventilation was 13.4 ± 10.7% lower in the CFM condition than in the CON condition (P < 0.001). The peak Vo2 (52.4 ± 5.6 and 55.0 ± 5.1 mL/kg/min in CFM and CON, respectively) and CO were not significantly different between the two conditions. However, the integral value of Pm was significantly higher (P = 0.02), and the running time to exhaustion was 2.6 ± 3.2% lower (P = 0.02) in the CFM condition than in the CON condition. Our results suggest that wearing a cloth face mask increased respiratory muscle effort and decreased ventilatory volume in healthy young men; however, Vo2 remained unchanged. Exercise tolerance also decreased slightly.

'Hook' Shape Lister Tubercle Is Associated with a Greater Incidence of Extensor Pollicis Longus Tendon Rupture after Distal Radius Fracture.

Background: A rupture of the extensor pollicis longus (EPL) tendon located close to the Lister tubercle is an uncommon complication of distal radius fractures. This study aimed to determine whether the size and shape of Lister tubercle in patients with EPL rupture differs from a matched group of patients with distal radius fractures without EPL rupture. Methods: We identified 15 patients with EPL rupture (3.5%) out of 426 with distal radius fractures treated conservatively at our hospital over 4 years. Out of the remaining 411 patients with distal radius fractures without EPL rupture, we selected patients using simple random sampling and pseudo-randomised them such that their age, sex and fracture type were matched with patients exhibiting EPL rupture. The size and shape of the Lister tubercle and the size of the EPL groove were measured in both groups using computed tomographic scans and compared. Results: There was no difference in the size of the Lister tubercle or the EPL groove between both groups. A 'hook'-shaped Lister tubercle was noted in 8 out of 15 patients with EPL rupture but in only 1 out of 15 matched patients without EPL rupture. Conclusions: A 'hook'-shaped Lister tubercle was seen more often in patients with EPL rupture following distal radius fracture. Level of Evidence: Level III (Therapeutic).

Analyzing Chronological Change in Postoperative Magnetic Resonance Imaging Results in Patients With Kienböck's Disease by Using an Original Grading System.

Background and objective Signal changes in MRI for Kienböck's disease have only been qualitatively assessed so far. In light of this, we proposed a new grading system for quantitative analysis with an ordinal scale. Methods The study included 31 patients (17 men, 14 women) with Kienböck's disease. By referring to Nakamura's MRI grading system, we devised a grading system with five grades (Grades 1-5) using proton density-weighted (PDW) coronal images with respect to the signal intensity of the lunate. All cases were examined by using the MRI grading system by three hand surgeons, both preoperatively and postoperatively. We evaluated the inter-rater reliability of our grading system by using the interclass correlation coefficient. After surgery, we implemented annual MRI evaluation for as long as possible and quantitatively assessed changes in MRI grades. We also investigated the correlation between postoperative MRI grades, Mayo Wrist Scores (MWS), and age at the surgery by using Pearson's coefficient. Results The MRI evaluation was performed 2-15 years after surgery. The reliability of our grading system was high; inter-rater interclass correlation coefficients were 0.783 (examiners 1-2), 0.780 (examiners 1-3), and 0.825 (examiners 2-3), representing a substantial agreement. The correlation coefficient between the MRI grade and MWS was -0.31, suggesting a mild negative correlation; postoperative MRI grade also correlated with age at surgery (Pearson's coefficient: 0.447). Conclusions Our proposed MRI grading system has high reliability and could be used to assess the regeneration of a necrotic lunate for quantitative analysis on an ordinal scale. Improvements were observed one to four years postoperatively, demonstrating a mild correlation with the clinical results.

Preoperative Predictions of Distal Screw Length for the Osteosynthesis of Distal Radius Fractures.

Background: The objective of this study was to clarify whether anteroposterior dimension of the radius along the screw axis of a fixed angle volar locking plate (VLP) can be predicted from the width of the radius on the VLP. Methods: Sixty-nine wrists in 68 patients with distal radius fractures that underwent fixation with a fixed angle VLPs were evaluated. All patients underwent pre- and postoperative computed tomographic scans of the distal radius. The transverse width of the radius was measured at the position of the third screw hole from the proximal edge. The anteroposterior dimension of the radius (R) was measured along the axes of the distal screws. The distal row screw holes were defined as R1, R2, R3, and R4 from the radial to the ulnar side. Correlation analysis between the width and the anteroposterior dimension, and single regression analysis were performed for each screw hole. The correlations amongst the R values for the different distal row screws were also assessed. Results: The correlation coefficients between the transverse width and anteroposterior dimensions were 0.54, 0.58, 0.55, and 0.42 for R1, R2, R3, and R4 respectively (p < 0.05). The regression equations were R1 = 0.49W + 7.99, R2 = 0.47W + 11.8, R3 = 0.52W + 10.8, and R4 = 0.41W + 11.5 respectively. The correlation coefficients among anteroposterior dimensions were 0.85, 0.64, 0.59, 0.70, 0.61, and 0.80 for R1/R2, R1/R3, R1/R4, R2/R3, R2/R4, and R3/R4 respectively (p < 0.01). Conclusions: There were significant correlations in the anteroposterior dimensions amongst the distal row screw lengths. The regression equations used in this study may be helpful to predict the length of distal row screw and prevent complications due to inappropriate screw choices. Level of Evidence: Level III (Therapeutic).

Preoperative Evaluation and Surgical Simulation for Osteochondritis Dissecans of the Elbow Using Three-Dimensional MRI-CT Image Fusion Images.

We used our novel three-dimensional magnetic resonance imaging-computed tomography fusion images (3D MRI-CT fusion images; MCFIs) for detailed preoperative lesion evaluation and surgical simulation in osteochondritis dissecans (OCD) of the elbow. Herein, we introduce our procedure and report the findings of the assessment of its utility. We enrolled 16 men (mean age: 14.0 years) and performed preoperative MRI using 7 kg axial traction with a 3-Tesla imager and CT. Three-dimensional-MRI models of the humerus and articular cartilage and a 3D-CT model of the humerus were constructed. We created MCFIs using both models. We validated the findings obtained from the MCFIs and intraoperative findings using the following items: articular cartilage fissures and defects, articular surface deformities, vertical and horizontal lesion diameters, the International Cartilage Repair Society (ICRS) classification, and surgical procedures. The MCFIs accurately reproduced the lesions and correctly matched the ICRS classification in 93.5% of cases. Surgery was performed as simulated in all cases. Preoperatively measured lesion diameters exhibited no significant differences compared to the intraoperative measurements. MCFIs were useful in the evaluation of OCD lesions and detailed preoperative surgical simulation through accurate reproduction of 3D structural details of the lesions.

Does the Radius Contain Bone Marrow Mesenchymal Stem Cells?-A Comparison between Cells of the Iliac Crest and Radius in Kienböck's Disease.

Background: Numerous studies have indicated the presence of mesenchymal stem cells (MSCs) in the bone marrow aspirated from the vertebral body, distal femur, proximal tibia, humeral head, sternum, and iliac crest. However, their presence has not been reported in the radius thus far. In this study, we aimed to compare the number of MSCs in bone marrow aspirated from radius and iliac crest in patients with Kienböck's disease. Furthermore, we examined the association between the number of MSCs in the bone marrow and patient age. Methods: A total of 17 patients were recruited. Owing to difficulties in obtaining samples for 5 cases, only 12 cases were included. Hematological analyses and fibroblastic colony-forming unit (CFU-F) assay were performed using bone marrow samples aspirated from the radius (group R), the first sample aspirated from the iliac crest (group I-1), and the second sample aspirated from the iliac crest (group I-2). The CFU-F numbers among the three groups were compared using Mann-Whitney U-test. Pearson's correlation coefficient was calculated to evaluate the association between the CFU-F numbers and patient age. Results: The average numbers of CFU-Fs/ml in the bone marrow samples from the R, I-1, and I-2 groups were 3.4, 57.3, and 13.7, respectively. The CFU-F number in Group I-1 was significantly higher than that in the other two groups; the CFU-F number was lower in group R than in group I-2. The correlation coefficients were -0.168, 0.166, and 0.036 for samples from groups R, I-1, and I-2, respectively. No significant association between the CFU-F numbers and patient age was observed. Conclusions: The presence of MSCs in the radius was indicated by CFU-Fs in patients with Kienböck's disease. The number of CFU-Fs was lower in the radius than in the iliac crest; the CFU-F number was not associated with patient age.

A multicentric study on the newly developed reconstruction locking plate for midshaft clavicular fracture.

Objectives: To examine the efficacy and clinical and radiological outcomes of the use of a streamlined clavicle plate® (MEIRA, Aichi, Japan) for midshaft clavicular fractures. Methods: This was a retrospective cohort study of 155 patients with displaced midshaft clavicular fractures treated using a streamlined clavicle plate between 2015 and 2019 in 18 hospitals across Japan. A questionnaire regarding bone union and postoperative complications was used, and 136 cases were followed up for one year or until bone union. Plate fitting was evaluated retrospectively using surgical records, radiographic findings, and surgeon's opinion. Results: During surgery, plate bending was needed in 19 cases (12.3%), poor fitting was observed in 8 cases (5.2%), and bone union was achieved in 133 cases (97.8%). Total implantation failure, including plate breakage and screw loosening, occurred in 10 cases (6.5%) from the intraoperative to postoperative period. Subjective complications were observed in 26 cases (16.8%): incongruity around the surgical scar or in the anterior chest in 23, and contracture of the shoulder in three. Plate removal was performed in 66 cases (48.5%) per patient's request. Conclusion: The use of a streamlined clavicle plate is effective for midshaft fractures of the clavicle, and the success rates of bone union and implantation using this approach are comparable to those of other existing plates.

An image fusion system for corrective osteotomy of distal radius malunion.

BACKGROUND: To provide surgical support for corrective osteotomy, we developed an image fusion system for three-dimensional (3D) preoperative planning and fluoroscopy. To assess the utility of this image fusion system, we evaluated the reproducibility of preoperative planning for corrective osteotomy of dorsally angulated distal radius malunion using the system and compared reproducibility without using the system. METHODS: Ten wrists from 10 distal radius malunion patients who underwent corrective osteotomy were evaluated. 3D preoperative planning and the image fusion system were used for the image fusion group (n = 5). Only 3D preoperative planning was used for the control group (n = 5). 3D preoperative planning was performed for both groups in order to assess reduction, placement, and the choice of implants. In the image fusion group, the outline of the planned image was displayed on a monitor and overlapped with fluoroscopy images during surgery. Reproducibility was evaluated using preoperative plan and postoperative 3D images. Images were compared with the 3D coordinates of the radial styloid process (1), the volar and dorsal edges of the sigmoid notch (2) (3), and the barycentric coordinates of the three reference points. The reproducibility of the preoperative plan was evaluated by the distance of the coordinates between the plan and postoperative images for the reference points. RESULTS: The distances between preoperative planning and postoperative reduction in the image fusion group were 2.1 ± 1.1 mm, 1.8 ± 0.7 mm, 1.9 ± 0.9 mm, and 1.4 ± 0.7 mm for reference points (1), (2), (3), and the barycenter, respectively. The distances between preoperative planning and postoperative reduction in the control group were 3.7 ± 1.0 mm, 2.8 ± 2.0 mm, 1.7 ± 0.8 mm, and 1.8 ± 1.2 mm for reference points (1), (2), (3), and the barycenter, respectively. The difference in reference point (1) was significantly smaller in the image fusion group than in the control group (P < 0.05). CONCLUSION: Corrective osteotomy using an image fusion system will become a new surgical support method for fracture malunion. Trial registration Registered as NCT03764501 at ClinicalTrials.gov.

Three-dimensional evaluations of preoperative planning reproducibility for the osteosynthesis of distal radius fractures.

BACKGROUND: Three-dimensional preoperative planning was applied for the osteosynthesis of distal radius fractures. The objective of this study was to evaluate the reproducibility of three-dimensional preoperative planning for the osteosynthesis of distal radius fractures with three-dimensional reference points. METHODS: Sixty-three wrists of 63 distal radius fracture patients who underwent osteosynthesis with three-dimensional preoperative planning were evaluated. After taking preoperative CT scans of the injured wrists, 3D images of the distal radius were created. Fracture reduction, implants choices, and placements simulation were performed based on the 3D images. One month after the surgery, postoperative CT images were taken. The reproducibility was evaluated with preoperative plan and postoperative 3D images. The images were compared with the three-dimensional coordinates of radial styloid process, volar and dorsal edges of sigmoid notch, and the barycentric coordinates of the three reference points. The reproducibility of the preoperative plan was evaluated by the distance of the coordinates between the plan and postoperative images for the reference points. The reproducibility of radial inclination and volar tilt on three-dimensional images were evaluated by intra-class correlation coefficient (ICC). RESULTS: The distances between the preoperative plan and the postoperative reduction for each reference point were (1) 2.1±1.3 mm, (2) 1.9±1.2 mm, and (3) 1.9±1.2 mm, respectively. The distance between the preoperative plan and postoperative reduction for the barycentric coordinate was 1.3±0.8 mm. ICCs were 0.54 and 0.54 for the volar tilt and radial inclination, respectively (P<0.01). CONCLUSIONS: Three-dimensional preoperative planning for the osteosynthesis of distal radius fracture was reproducible with an error of about 2 mm for each reference point and the correlations of reduction shapes were moderate. The analysis method and reference points may be helpful to understand the accuracy of reductions for the three-dimensional preoperative planning in the osteosynthesis of distal radius fractures. TRIAL REGISTRATION: Registered as NCT02909647 at ClinicalTrials.gov.

Positional anterior sternoclavicular joint dislocation in the acceleration phase of throwing: a case report.

Positional anterior sternoclavicular joint (SCJ) dislocation is relatively rare and needs careful treatment. We report our course of treatment and tips for surgery in a case. The patient was a 16-year-old male outfield baseball player. Three years ago, he had 3 recurrent episodes of right shoulder dislocation. During these injuries, there were forward dislocations of the proximal right clavicle edge accompanied by a creaking sound during the throw acceleration period. Thereafter, the anterior dislocation of the SCJ occurred during the acceleration phase of throwing, and the SCJ naturally repositioned on the shoulder resting position. This situation lingered and he often felt shoulder apprehension during throws, so he opted for surgical treatment just 1 month after the first injury. We performed a modified version of the figure-of-8 technique reported by Wang et al, using the ipsilateral palmaris longus (PL) tendon. The bilateral edge of the PL was attached to a Krackow suture and passed through the bone tunnels opened at the proximal clavicle and proximal sternum so that it became a figure of 8 on the anterior of the SCJ. The stability of the SCJ was confirmed after the surgery.

Effects of Fibroblast Growth Factor-2 Combined With a Collagen/Gelatin Sponge for Adipogenesis in the Mouse Subcutis.

INTRODUCTION: A collagen/gelatin sponge (CGS) is a new scaffold that promotes wound healing by slowly releasing fibroblast growth factor (FGF)-2. FGF-2 induces mitogenesis, angiogenesis, and adipogenesis. In this study, the adipogenesis-inducing effects of CGS combined with FGF-2 in the subcutis of mice were evaluated. METHODS: Collagens/gelatin sponges (10 × 5 mm) were impregnated with 50 µL of FGF-2 solution (10 or 100 µg/mL). A CGS (Gunze Corp, Osaka, Japan) combined with FGF-2 was implanted subcutaneously into the thoracic region of mice. At 1, 2, 3, and 4 weeks, samples were collected for hematoxylin and eosin staining, von Willebrand factor immunostaining, and perilipin immunostaining to examine adipose tissue localization and angiogenesis. A CGS with only saline solution was prepared as a control. RESULTS: Adipocytes in the collagen fibers appeared at 3 weeks, and a zonal fat layer was noted under the panniculus carnosus at 4 weeks in the FGF-2-combined CGS groups. The fat layer was significantly thicker in the FGF-2 (100 µg/mL) group than in the FGF-2 (10 µg/mL) group. In the control group, no fat pad was newly formed. The number of newly formed vessels in the FGF (10 µg/mL) and (100 µg/mL) groups was significantly greater in the FGF-2 group than in the control group. CONCLUSION: This study presents a promising method to enhance adipogenic effects in the murine subcutis using CGS combined with FGF-2, representing a potential technique for soft tissue reconstruction.

Automated Muscle Segmentation from Clinical CT Using Bayesian U-Net for Personalized Musculoskeletal Modeling.

We propose a method for automatic segmentation of individual muscles from a clinical CT. The method uses Bayesian convolutional neural networks with the U-Net architecture, using Monte Carlo dropout that infers an uncertainty metric in addition to the segmentation label. We evaluated the performance of the proposed method using two data sets: 20 fully annotated CTs of the hip and thigh regions and 18 partially annotated CTs that are publicly available from The Cancer Imaging Archive (TCIA) database. The experiments showed a Dice coefficient (DC) of 0.891±0.016 (mean±std) and an average symmetric surface distance (ASD) of 0.994±0.230 mm over 19 muscles in the set of 20 CTs. These results were statistically significant improvements compared to the state-of-the-art hierarchical multi-atlas method which resulted in 0.845 ± 0.031 DC and 1.556 ± 0.444 mm ASD. We evaluated validity of the uncertainty metric in the multi-class organ segmentation problem and demonstrated a correlation between the pixels with high uncertainty and the segmentation failure. One application of the uncertainty metric in active-learning is demonstrated, and the proposed query pixel selection method considerably reduced the manual annotation cost for expanding the training data set. The proposed method allows an accurate patient-specific analysis of individual muscle shapes in a clinical routine. This would open up various applications including personalization of biomechanical simulation and quantitative evaluation of muscle atrophy.

FGF-2 combined with bilayer artificial dermis composed of collagen matrix prompts generation of fat pad in subcutis of mice.

Fibroblast growth factor (FGF)-2 induces mitogenesis, angiogenesis and adipogenesis. In this study, the adipogenesis-inducing effects of FGF-2 combined with bilayer artificial dermis in mice were evaluated. FGF-2-impregnated bilayer artificial dermis composed of collagen matrix, PELNAC (Gunze Corp., Osaka, Japan) was implanted subcutaneously into the thoracic region of mice. At 1, 2, 3, and 4 weeks, samples were collected for H&E staining, von Willebrand factor immunostaining, and perilipin immunostaining to examine adipose tissue localization and angiogenesis. The collagen matrix-implanted group without the addition of FGF-2 was prepared as a control. At 2 weeks after the implantation of FGF-2 combined with dermal substitutes, adipocytes appeared in the collagen fibers. At 3-4 weeks, a fat pad was generated with neovascularization. The thickness of the fat pad had significantly increased at 2, 3, and 4 weeks. The remaining collagen was decreased by absorption over time. In the control group, no fat pad was newly formed. This study has identified a promising method to enhance adipogenic effects in the murine subcutis, representing a potential technique for soft tissue reconstruction.

Locked Metacarpophalangeal Joint of the Little Finger in Extension Position due to the Incarceration of a Chronic Fracture Fragment: A Case Report.

We managed a case of locked metacarpophalangeal joint of the little finger in the extension position. Incarceration of a chronic osteochondral fracture fragment led to this unique condition. The fracture fragment partially adhered to the volar plate and ulnar collateral ligament on the joint side, which is supposed to have resulted in manually irreducible locking of the joint. We performed open reduction and achieved release of the locked joint by excising the fracture fragment.

Existing or Worsening Symptoms of Kienböck's Disease after Distal Radius Fracture: Two Case Reports.

We report two rare cases of existing or worsening symptoms due to Kienböck's disease after distal radius fracture (DRF). During examination, radiographs show changes in the lunate bone; there was persistent wrist pain after treatment for DRF. In each case, surgeries were performed: A combined therapy (bone marrow transfusion, bone peg graft, external fixation, and low intensity pulsed ultrasound) for one, as well as carpal coalition for another. The etiology of these case presentations suggest that a compression fracture of the lunate due to a DRF resulted in softening and sclerosis.