Nail Bed Injury Repair: Nail Plate Replacement Versus Non-replacement.

Background: Although nail bed injuries are common, there is no consensus on the proper course of treatment in regard to nail plate replacement. Nail plate replacement risks infection and injury of the germinal matrix. It is our hypothesis that functional and cosmetic outcomes of the nail will not differ by nail plate replacement following nail bed repair. Methods: This is a single institution, prospective, randomized control study comparing nail plate replacement versus non-replacement in patients undergoing nail bed repair. Primary outcome included nail growth and cosmesis using the Zook classification system. Secondary outcomes were pain, functional limitation, and patient satisfaction. Statistical significance was set at P < .05. Results: Fifty patients were enrolled, 26 (52%) randomized to the non-replacement group and 24 (48%) to the replacement group. All patients who followed up had nail growth by 4 months after nail bed repair (N = 28). In the non-replacement group 4 patients continued to have pain in the affected nail bed compared with 2 patients in the replacement group (P = .66). One patient in each group reported continued functional limitation related to nail pain (P = 1.00). Patient satisfaction was not statistically different between the groups (P = 1.00). As a result of patient follow- up, we have been able to score 17 patients via the Zook criteria. In the non-replacement group, 3 nails were scored as excellent, 3 very good, 3 good, 1 fair, and 2 poor. In the replacement group, the nail was classified as excellent in 4 patients and very good in 1 patient. There was no difference in the likelihood of these outcomes with regard to treatment group (P = .18). There was moderate agreement between patient satisfaction and the Zook criteria scoring (κ = .45, 95% CI: -0.15-1.00). Conclusions: Statistical and clinical differences were not identified in regard to cosmesis, pain, functional use of the hand, or patient satisfaction. There are established risks involved in nail plate replacement such as infection and injury to the germinal matrix. If outcomes are not different based on nail plate replacement following nail bed repair, non- replacement may be the preferable treatment option so as to avoid these complications.

Self-perceived middle-distance race pace is faster in advanced footwear technology spikes.

BACKGROUND: Quantifying the potential benefits of advanced footwear technology (AFT) track shoes (i.e., "spikes") in middle-distance events is challenging, because repeated maximal effort trials (as in sprinting) or aerobic running economy trials (as in long-distance running) are not feasible. METHODS: We introduce a novel approach to assess the benefits of AFT spikes, consisting of a series of 200-m runs at self-perceived middle-distance race pace with 10 min recovery, and conduct 4 experiments to evaluate its validity, sensitivity, reproducibility, and utility. RESULTS: In Experiment 1, participants ran 1.2% slower in spikes with 200 g added mass vs. control spikes, which is exactly equal to the known effects of shoe mass on running performance. In Experiment 2, participants ran significantly faster in AFT prototype spikes vs. traditional spikes. In Experiment 3, we compared 2 other AFT prototype spikes against traditional spikes on 3 separate days. Group-level results were consistent across days, but our data indicates that at least 2 separate sessions are needed to evaluate individual responses. In Experiment 4, participants ran significantly faster in 2 AFT spike models vs. traditional spikes (2.1% and 1.6%). Speed was similar between a third AFT spike model and the traditional spikes. These speed results were mirrored by changes in step length as participants took significantly longer steps in the 2 faster AFT spike models (2.3% and 1.9%), while step length was similar between the other spikes. CONCLUSION: Our novel, interval-based approach is a valid and reliable method for quantifying differences between spikes at middle-distance running intensity.

Enhanced Maturity and Functionality of Vascularized Human Liver Organoids through 3D Bioprinting and Pillar Plate Culture.

Liver tissues, composed of hepatocytes, cholangiocytes, stellate cells, Kupffer cells, and sinusoidal endothelial cells, are differentiated from endodermal and mesodermal germ layers. By mimicking the developmental process of the liver, various differentiation protocols have been published to generate human liver organoids (HLOs) in vitro using induced pluripotent stem cells (iPSCs). However, HLOs derived solely from the endodermal germ layer often encounter technical hurdles, such as insufficient maturity and functionality, limiting their utility for disease modeling and hepatotoxicity assays. To overcome this, we separately differentiated EpCAM+ endodermal progenitor cells (EPCs) and mesoderm-derived vascular progenitor cells (VPCs) from the same human iPSC line. These cells were then mixed in BME-2 matrix and concurrently differentiated into vascular human liver organoids (vHLOs). Remarkably, vHLOs exhibited significantly higher maturity than vasculature-free HLOs, as demonstrated by increased coagulation factor secretion, albumin secretion, drug-metabolizing enzyme (DME) expression, and bile acid transportation. To enhance assay throughput and miniaturize vHLO culture, we 3D bioprinted expandable HLOs (eHLOs) in BME-2 matrix on a pillar plate platform derived from EPCs and VPCs and compared with HLOs derived from endoderm alone. Compared to HLOs cultured in a 50 µL BME-2 matrix dome in a 24-well plate, vHLOs cultured on the pillar plate exhibited superior maturity, likely due to enhanced nutrient and signaling molecule diffusion. The integration of physiologically relevant patterned liver organoids with the unique pillar plate platform enhanced the capabilities for high-throughput screening and disease modeling.

The fibular intramedullary nail versus plate fixation for ankle fractures in adults: a systematic review and meta-analysis of randomized controlled trials.

OBJECTIVE: The effectiveness and safety of fibular intramedullary nail fixation (FINF) compared to plate fixation (PF) in treating ankle fractures among adults remains unclear. Therefore, we conducted a meta-analysis to assess the efficacy and safety of FINF versus PF, aiming to provide orthopedic surgeons with valuable insights when choosing between the two internal fixation methods for patient treatment. METHODS: PubMed, EMBASE, and SCOPUS were systematically searched for articles comparing FINF and PF in ankle fractures among adults. Functional outcomes, complications, and bony union were compared between the implants. RESULTS: A total of seven studies were included in the study, involving 586 patients. The results revealed no statistically significant differences in functional outcomes between two groups at 3, 6, and 12 months postoperatively. The outcomes favoring FINF comprised a lower infection rate (RR = 0.23, 95%CI, 0.11 to 0.47, P < 0.0001). Conversely, the PF group exhibited a superior performance in terms of hardware failure rate (RR = 2.05, 95%CI, 1.16 to 3.60, P = 0.01). A statistically significant difference was observed in the results of hardware failure rate in the subgroup of studies conducted in Europe (RR = 2.74, 95%CI, 1.45 to 5.18, P = 0.002). Comparable findings were also noted in a subgroup of older adults (RR = 4.25, 95%CI, 1.57 to 11.50, P = 0.004). CONCLUSION: This systematic review suggests that FINF exhibits comparable effectiveness in the management of ankle fractures among adults, as compared to PF. Consequently, it is imperative to further delineate the surgical indications for both FINF and PF with precision to mitigate the risk of complications. Nevertheless, larger sample sizes and multi-center RCTs are imperative to corroborate this conclusion in the future.

Stable laminar shear stress induces G1 cell cycle arrest and autophagy in urothelial carcinoma by a torque sensor-coupled cone-and-plate device.

The microenvironments of urinary systems play crucial roles in the development and metastasis of cancers due to their generation of complex temporal and spatial fluidic profiles. Because of their versatility in creating desired biomimetic flow, cone-and-plate bioreactors offer great potential for bladder cancer research. In this study, we construct a biocompatible cone-and-plate device coupled with a torque sensor, enabling the application and real-time monitoring of stable shear stress up to 50 dyne/cm². Under a stable shear stress stimulation at 12 dyne/cm2, bladder cancer cell BFTC-905 is arrested at the G1 phase with decreased cell proliferation after 24-hour treatment. This effect is associated with increased cyclin-dependent kinase inhibitors p21 and p27, inhibiting cyclin D1/CDK4 complex with dephosphorylation of serine 608 on the retinoblastoma protein. Consequently, an increase in cyclin D3 and decreases in cyclin A2 and cyclin E2 are observed. Moreover, we demonstrate that the shear stress stimulation upregulates the expression of autophagy-related proteins Beclin-1, LC3B-I and LC3B-II, while caspase cleavages are not activated under the same condition. The design of this system and its application shed new light on flow-induced phenomena in the study of urothelial carcinomas.

Dorsal blocking orthoses for proximal interphalangeal joint volar plate injuries: A retrospective cohort study investigating the impact of joint angle on patient outcomes.

BACKGROUND: Injuries to the proximal interphalangeal joint (PIPJ) of the fingers are commonly treated in hand therapy departments. Conservative management for PIPJ volar plate injuries typically involves a dorsal blocking orthosis and flexion exercises. Historically hand therapists have placed the PIPJ in varying degrees of flexion but the optimal angle is unknown. PURPOSE: To compare the outcomes of two treatment groups who received dorsal blocking orthoses: Those who the orthosis was positioned in neutral compared to those in 25-30° of flexion. STUDY DESIGN: Retrospective cohort study. METHOD: Patients treated by the hand therapy service at a major metropolitan hospital network in Melbourne, Australia, for conservative management of a PIPJ volar plate injury over a three-year period were included in our study. Data regarding patient demographics, digits affected and injury type were collected. Outcomes included presence of a fixed flexion deformity (FFD), amount of hand therapy received and total active flexion at the PIPJ. RESULTS: One hundred and eleven participants were included in our study. The mean age was 26 and 59 (53%) were males. Seventy two (64%) participants received a dorsal blocking orthosis positioned in neutral and 39 (35%) were positioned in 25-30° flexion at the PIPJ. Participants whose orthosis was positioned at 25-30° had an average of 24 more minutes in hand therapy (which equates to approximately one appointment) compared to those whose PIPJ was positioned in neutral (p=0.006, d=0.5). Eight percent less participants developed a FFD (p = 0.24) and 13% more participants achieved full flexion (p = 0.06) in the group who received a dorsal blocking orthosis in neutral, however these results were not statistically significant. CONCLUSION: PIPJ volar plate injures treated in an orthosis positioned in neutral required fewer hand therapy appointments. There was no statistically significant difference between groups regarding development of a FFD or full flexion.

Locking plate augmentation of polymethylmethacrylate-filled distal femoral defects: A biomechanical study.

Benign, locally aggressive tumors of the distal femur are typically treated with intralesional curettage and polymethylmethacrylate (PMMA) cementation. However, it is not known whether plate fixation should be added to biomechanically augment these PMMA-filled defects. The purpose of this study was to evaluate the performance of two competing techniques for reconstruction of a distal femoral defect. For this biomechanical study, we used 12 composite femurs with properties comparable to bone. In nine femurs, identical contained medial distal femoral defects were created using a robotic arm. Group A contained three intact femurs, Group B three femurs with an unfilled defect, Group C three femurs reconstructed with PMMA alone, and Group D three femurs reconstructed with PMMA plus a medial locking plate. Locations of greatest stress concentration were determined by PhotoStress analysis, then three strain gauges were applied to each specimen at these high-stress locations. Specimens were loaded within a physiologic range followed by loading to failure. Outcome measures included construct stiffness, strain along the distal femur, and load at failure. Results showed that stiffness and strain were not significantly different between reconstructive techniques; however, both techniques reduced tensile strain along the popliteal surface by approximately 40% compared to non-reconstructed specimens. All specimens failed at the femoral neck before failing at the distal femur. These findings suggest that plate augmentation of PMMA-filled distal femoral defects like the one in this study offers insignificant biomechanical benefit within physiologic loads and therefore may be unnecessary.

The G protein-coupled receptor ADGRG6 maintains mouse growth plate homeostasis through IHH Signaling.

The cartilage growth plate is essential for maintaining skeletal growth; however, the mechanisms governing postnatal growth plate homeostasis are still poorly understood. Using approaches of molecular mouse genetics and spatial transcriptomics applied to formalin-fixed, paraffin-embedded (FFPE) tissues, we show that ADGRG6/GPR126, a cartilage-enriched adhesion G protein-coupled receptor (GPCR), is essential for maintaining slow-cycling resting zone cells, appropriate chondrocyte proliferation and differentiation, and growth plate homeostasis in mice. Constitutive ablation of Adgrg6 in osteochondral progenitor cells with Col2a1Cre leads to a shortened resting zone, formation of cell clusters within the proliferative zone, and an elongated hypertrophic growth plate, marked by limited expression of PTHrP but increased IHH signaling throughout the growth plate. Attenuation of Smoothened (SMO)-dependent hedgehog signaling restored the Adgrg6 deficiency-induced expansion of hypertrophic chondrocytes, confirming that IHH signaling can promote chondrocyte hypertrophy in a PTHrP-independent manner. In contrast, postnatal ablation of Adgrg6 in mature chondrocytes with AcanCreERT2, induced after the formation of the resting zone, does not affect PTHrP expression but causes an overall reduction of growth plate thickness marked by increased cell death specifically in the resting zone cells and a general reduction of chondrocyte proliferation and differentiation. Spatial transcriptomics reveals that ADGRG6 is essential for maintaining chondrocyte homeostasis by regulating osteogenic and catabolic genes in all the zones of the postnatal growth plates, potentially through positive regulation of SOX9 expression. Our findings elucidate the essential role of a cartilage-enriched adhesion GPCR in regulating cell proliferation and hypertrophic differentiation by regulation of PTHrP/IHH signaling, maintenance of slow-cycle resting zone chondrocytes, and safeguarding chondrocyte homeostasis in postnatal mouse growth plates.

The cartilage growth plate is an essential structure for skeletal growth, however, the mechanisms that govern growth plate homeostasis are still poorly understood. In this study, we showed that an adhesion G protein-coupled receptor (GPCR) named ADGRG6 plays an essential role in maintaining the slow-cycling cells in the resting zone of the growth plate and directing appropriate proliferation and differentiation of the growth plate chondrocytes. Using a technique called spatial transcriptomics, we compared the gene expression profiles in control and Adgrg6 mutant growth plates and found that ADGRG6 prevents premature hypertrophic differentiation of the growth plate chondrocytes by negatively regulating Indian Hedgehog (IHH) signaling. In summary, our findings highlighted the essential role of a cartilage-enriched GPCR in maintaining growth plate homeostasis through IHH signaling.

Experimental and numerical study on explosion resistance of polyurea-coated shelter in petrochemical industry.

To reduce the number of casualties in explosion accidents, blast-resistant shelters can be used to protect personnel in high-risk areas of petrochemical processing plants. In this work, the deformation behaviours of uncoated and polyurea-coated blast-resistant plates were studied through gas explosion tests. An ANSYS/LS-DYNA model of a polyurea-coated shelter was established, and the dynamic responses of the shelter under various explosion loads were analysed. A series of fuel-air explosion tests were carried out to investigate the explosion resistance of the full-scale shelter. The results showed that compared with the uncoated blast-resistant plate, the deformation of the polyurea-coated blast-resistant plate was significantly reduced. The overall deformation of the shelter was the central depression of the wall and the inward bending of the frame. The damage effect of a typical high-overpressure, low-duration load was greater than that of typical low-overpressure, long-duration load. The shelter remained intact under three repeated explosive loads, with cracks appearing on the inner wall but no collapse or debris splashing. The shock wave attenuation rate of the shelter reached over 90%, which could significantly reduce the number of indoor casualties.

Distal femoral fractures: periprosthetic fractures have four times more complications than non-periprosthetic fractures and cerclage should be avoided: retrospective analysis of 206 patients.

BACKGROUND: Distal femoral fractures account for less than 1% of all fractures. The therapy of choice is usually surgical stabilization. Despite advances in implant development over the past few years, complication rate remains comparatively high. The aim of this study is to analyze our results with plate fixation of distal femoral fractures with a focus on complication and fracture healing rates. METHODS: In this retrospective cohort study, patients (> 18 years) with distal femoral fractures treated at an urban level I trauma center between 2015 and 2022 were analyzed. RESULTS: In total, 206 patients (167 female, 39 male) with an average age of 75 (SD 16) years were diagnosed with a fracture of the distal femur. One hundred fourteen of these patients were treated surgically by means of plate osteosynthesis. In 13 cases (11.41%), a revision procedure had to be performed. The indication for surgical revision was mechanical failure in eight cases (7.02%) and septic complication in five cases (4.39%). Periprosthetic fractures were more likely to cause complications overall (19.6% versus 4.76%) and further included all documented septic complications. The analysis of modifiable surgical factors in the context of plate osteosynthesis showed higher complication rates for cerclage in the fracture area compared with plate-only stabilizations (44.44% versus 22.22%). CONCLUSIONS: The data show an increased amount of revisions and a significantly higher number of septic complications in the treatment of periprosthetic fractures of the distal femur compared with non-periprosthetic fractures. The detected combination of plates together with cerclage was associated with higher complication rates. Level of evidence Level III retrospective comparative study.

Fracture-Related Infection of a Distal Femur Open Fracture Treated With a Supracutaneous Locking Plate.

Fracture-related infection (FRI) is a challenging complication in open fractures. It can cause major disability to patients and a burden to the public health sector. A multidisciplinary approach is required to eradicate infection and improve the quality of life for patients. We present a case of an FRI in an open fracture of the distal femur treated using a supracutaneous locking plate, which is an uncommon technique. This technique yields excellent outcomes in controlling local infection and providing satisfactory stability, especially for a peri-articular distal femur fracture with FRI. Therefore, supracutaneous plating using a locking plate can be considered an alternative option to conventional external fixations in managing FRIs.

Biomechanical design of a new proximal humerus fracture plate using alternative materials.

Comminuted proximal humerus fractures are often repaired by metal plates, but potentially still experience bone refracture, bone "stress shielding," screw perforation, delayed healing, and so forth. This "proof of principle" investigation is the initial step towards the design of a new plate using alternative materials to address some of these problems. Finite element modeling was used to create design graphs for bone stress, plate stress, screw stress, and interfragmentary motion via three different fixations (no, 1, or 2 "kickstand" [KS] screws across the fracture) using a wide range of plate elastic moduli (EP = 5-200 GPa). Well-known design optimization criteria were used that could minimize bone, plate, and screw failure (i.e., peak stress < ultimate tensile strength), reduce bone "stress shielding" (i.e., bone stress under the new plate ≥ bone stress for an intact humerus, titanium plate, and/or steel plate "control"), and encourage callus growth leading to early healing (i.e., 0.2 mm ≤ axial interfragmentary motion ≤ 1 mm; shear/axial interfragmentary motion ratio <1.6). The findings suggest that a potentially optimal configuration involves the new plate being manufactured from a material with an EP of 5-41.5 GPa with 1 KS screw; but, using no KS screws would cause immediate bone fracture and 2 KS screws would almost certainly lead to delayed healing. A prototype plate might be fabricated using alternative materials suggested for orthopedics and other industries, like fiber-metal laminates, fiber-reinforced polymers, metal foams, pure polymers, shape memory alloys, or 3D-printed porous metals.

Headless screw fixation of unstable ulnar styloid base fractures after distal radial fractures fixation.

Ulnar styloid fractures occur frequently concomitant with distal radial fractures. Although unstable distal radial fractures are mostly surgically treated, ulnar styloid fractures are often ignored. Unstable fractures at the base of the ulnar styloid may lead to persistent ulnar pain, due to distal radioulnar joint instability or ulnar styloid non-union. We retrospectively analyzed a single-surgeon cohort series of surgically treated distal radial fractures on how these concomitant ulnar styloid fractures were regarded: indications for surgery and surgical technique with headless screw fixation. 119 surgically treated distal radial fractures were assessed. 51 (42.8%) of the surgically treated distal radial fractures had a distal ulnar fracture, and more specifically 23 (19.3%) had a base fracture of the ulnar styloid. 9 (7.6%) of the wrists had a base fracture of the ulnar styloid which was considered after distal radial fracture fixation as persistently unstable, during distal radioulnar joint ballottement translation test. This fracture subtype was immediately treated with headless screw fixation, resulting in all cases in bony union, with a mean active pronation of 85°, a mean active supination of 80° and a clinical stable distal radioulnar joint, with minimal ulnar pain after 6 weeks (mean Visual Analogue Scale 1). After at least 12 months, persistent pain did not occur and mean QuickDASH was 2.5. According to this single-surgeon cohort series, headless screw fixation provides a reliable treatment for unstable base fractures of the ulnar styloid after distal radial fixation.

Factors influencing surgical outcomes of fixation with locking plate for three- and four-part proximal humerus fractures in patients aged 50 ​Years and older.

Background: Treating complex three- and four-part proximal humerus fractures, especially in the elderly, remains contentious, with internal fixation using locking plates and shoulder arthroplasty being primary options. Although proximal humerus locking plates are more commonly used than shoulder replacements, they have a high complication rate. Factors like low bone density, advanced age, multiple fragment fractures, and medial cortical support loss negatively impact treatment outcomes. This study evaluates the functional and radiographic outcomes of using locking plates for treating these fractures in patients aged 50 and older, and the factors influencing outcomes and complication rates at the Ho Chi Minh City Hospital for Trauma and Orthopedics. Method: A descriptive case series study was conducted on 58 patients aged 50 and older (15 males, 43 females) with three- and four-part proximal humerus fractures. These patients underwent open reduction and internal fixation with Locking - compression plate (LCP) periarticular proximal humerus plates at the Ho Chi Minh City Hospital for Traumatology and Orthopedics (HTO) from April 2020 to April 2022. The minimum postoperative follow-up period was 12 months. Results: The average age of the patients was 62.78 â€‹± â€‹7.73 years, with a mean follow-up of 26.24 â€‹± â€‹5.93 months. Among them, 41 had three-part fractures (70.68 â€‹%) and 17 had four-part fractures (29.32 â€‹%). At the final follow-up (≥12 months), the mean Constant-Murley score was 70.81 â€‹± â€‹9.15, and the mean QDASH score was 8.33 â€‹± â€‹2.77. Complications occurred in 6 cases (10.34 â€‹%). Complex fractures, such as four-part fractures with displacement greater than 2 â€‹mm, had lower Constant-Murley scores and higher QDASH scores (p â€‹< â€‹0.05). Age, gender, bone density by deltoid tuberosity index (DTI), bone grafting, and rotator cuff sutures showed similar trends, but the differences were not statistically significant. Conclusion: Open reduction and internal fixation (ORIF) provides good bone healing and functional outcomes for three- and four-part proximal humerus fractures. Factors such as age, gender, bone density, bone grafting, and rotator cuff sutures do not significantly affect outcomes. Therefore, osteoporosis should not be a contraindication for ORIF with locking plates in these cases. Complex fractures, however, often lead to poorer outcomes and higher complication rates post-surgery.

Current Concepts in Management of Distal Femur Fractures.

Recent studies report the overall incidence of distal femur fractures as 8.7/100,000/year. This incidence is expected to rise with high energy motor vehicle collisions and elderly osteoporotic fractures in native and prosthetic knees keep increasing. These fractures are more common in males in the younger age spectrum while females predominate for elderly osteoporotic fractures. Surgical treatment is recommended for these fractures to maintain articular congruity, enable early joint motion and assisted ambulation. Over the last two decades, development of minimally invasive and quadriceps sparing surgical approaches, availability of angle stable implants have helped achieve predictable healing and early return to function in these patients. Currently, laterally positioned locked plate is the implant of choice across all fracture patterns. Retrograde with capital implantation of intramedullary nails with provision for multiplanar distal locking is preferred for extra-articular and partial articular fractures. Even with these advancements, nonunion after distal femur fracture fixation can be as high as 19%. Further recent research has helped us understand the biomechanical limitations and healing problems with lateral locked plate fixation and intramedullary nails. This has lead to development of more robust constructs such as nail-plate and double plate constructs aiming for improved construct strength and to minimise failures. Early results with these combination constructs have shown promise in high risk situations such as fractures with extensive metaphyseal fragmentation, osteoporosis and periprosthetic fractures. These constructs however, run the risk of being over stiff and can inhibit healing if not kept balanced. The ideal stiffness that is needed for fracture healing is not clearly known and current research in this domain has lead to the development of smart implants which are expected to evolve and may help improve clinical results in future.

Proximal humerus fracture and acromioclavicular joint dislocation.

Proximal humerus fractures and injuries to the acromioclavicular joint are among the most common traumatic diseases of the upper extremity. Fractures of the proximal humerus occur most frequently in older people and are an indicator fracture of osteoporosis. While a large proportion of only slightly displaced fractures can be treated non-operatively, more complex fractures require surgical treatment. The choice of optimal treatment and the decision between joint-preserving surgery by means of osteosynthesis or endoprosthetic treatment is often a difficult decision in which both fracture morphology factors and individual factors should be taken into account. If endoprosthetic treatment is indicated, satisfactory long-term functional and clinical results have been achieved with a reverse shoulder arthroplasty. Injuries to the acromioclavicular joint occur primarily in young, athletic individuals. The common classification according to Rockwood divides the injury into 6 degrees of severity depending on the dislocation. This classification forms the basis for the decision on non-operative or surgical treatment. The indication for surgical treatment for higher-grade injuries is the subject of controversial debate in the latest literature. In chronic injuries, an autologous tendon transplant is also performed. Whereas in the past, treatment was often carried out using a hook plate, which was associated with complications, the gold standard today is minimally invasive treatment using Endobutton systems. This review provides an overview of the two injury patterns and discusses the various treatment options.

Risk Factors for Dysfunctional Elbow Stiffness following Operative Fixation of Distal Humerus Fractures.

BACKGROUND: Elbow stiffness is one of the most common complications after operative fixation of distal humerus fractures; however, there is relatively limited literature assessing which factors are associated with this problem. The purpose of this study is to identify risk factors associated with dysfunctional elbow stiffness in distal humerus fractures after operative fixation. METHODS: A retrospective review of all distal humerus fractures that underwent operative fixation (AO/OTA 13A-C) at a single level 1 trauma center from November 2014 to October 2021. A minimum six-month follow-up was required for inclusion or the outcome of interest. Dysfunctional elbow stiffness was defined as a flexion-extension arc of less than 100° at latest follow-up or any patient requiring surgical treatment for limited elbow range of motion. RESULTS: A total of 110 patients with distal humerus fractures were included in the study: 54 patients comprised the elbow stiffness group and 56 patients were in the control group. Average follow-up of 343 (59 to 2,079) days. Multiple logistic regression showed that orthogonal plate configuration (aOR: 5.70, 95% CI: 1.91-16.99, p=0.002), and longer operative time (aOR: 1.86, 95% CI: 1.11-3.10, p=0.017) were independently associated with an increased odds of elbow stiffness. OTA/AO 13A type fractures were significantly associated with a decreased odds of stiffness (aOR: 0.16, 95% CI: 0.03-0.80, p=0.026). Among 13C fractures, olecranon osteotomy (aOR: 5.48, 95% CI: 1.08-27.73, p=0.040) was also associated with an increased odds of elbow stiffness. There were no significant differences in injury mechanism, Gustilo-Anderson classification, reduction quality, days to surgery from admission, type of fixation, as well as rates of ipsilateral upper extremity fracture, neurovascular injury, nonunion, or infection between the two groups. CONCLUSION: Dysfunctional elbow stiffness was observed in 49.1% of patients who underwent operative fixation of distal humerus fractures in the present study. Orthogonal plate configuration, olecranon osteotomy, and longer operative time were associated with an increased odds of dysfunctional elbow stiffness; however, 13A type fractures were associated with decreased odds of stiffness. Patients with these injuries should be counseled on their risk of stiffness following surgery, and modifiable risk factors like plate positioning and performing an olecranon osteotomy should be considered by surgeons.

Treatment of supracondylar fractures of the humerus in adults using a novel anatomical locking plate on the anterior distal humerus: a case report.

BACKGROUND: Due to its unique anatomical characteristics, supracondylar fractures of the humerus are often difficult to achieve firm fixation with internal fixation equipment, resulting in delayed functional exercise, often leaving cubitus varus deformity, elbow stiffness, contractures, and other complications. Here, we report an adult patient with a supracondylar fracture of the humerus who underwent internal fixation through an anterior median incision in the humerus with our self-developed anterior anatomical locking plate of the distal humerus. CASE PRESENTATION: A 29-year-old male patient of Chinese ethnicity with trauma-induced right supracondylar fracture of the humerus and multiple soft tissue contusions, without nerve damage, blood vessel damage, or other injuries, underwent an internal incision in our hospital using a new anatomical locking plate for the anterior distal humerus fixed treatment. During the 16-month follow-up period, the patient's elbow range of motion was almost completely restored, functional scores were excellent, and there were no minor or major postoperative complications. CONCLUSION: In this study, we propose a surgical reconstruction strategy for adult patients with supracondylar humeral fractures. Through the anterior median incision of the humerus, open reduction and internal fixation were performed with an anatomic locking plate on the anterior side of the distal humerus to restore and fix the structure of the distal humerus, and satisfactory clinical results were achieved in our case.

Tibial Damage Caused by T-2 Toxin in Goslings: Bone Dysplasia, Poor Bone Quality, Hindered Chondrocyte Differentiation, and Imbalanced Bone Metabolism.

T-2 toxin, the most toxic type A trichothecene, is widely present in grain and animal feed, causing growth retardation and tissue damage in poultry. Geese are more sensitive to T-2 toxin than chickens and ducks. Although T-2 toxin has been reported to cause tibial growth plate (TGP) chondrodysplasia in chickens, tibial damage caused by T-2 toxin in geese has not been fully demonstrated. This study aims to investigate the adverse effects of T-2 toxin on tibial bone development, bone quality, chondrocyte differentiation, and bone metabolism. Here, forty-eight one-day-old male Yangzhou goslings were randomly divided into four groups and daily gavaged with T-2 toxin at concentrations of 0, 0.5, 1.0, and 2.0 mg/kg body weight for 21 days, respectively. The development of gosling body weight and size was determined by weighing and taking body measurements after exposure to different concentrations of T-2 toxin. Changes in tibial development and bone characteristics were determined by radiographic examination, phenotypic measurements, and bone quality and composition analyses. Chondrocyte differentiation in TGP and bone metabolism was characterized by cell morphology, tissue gene-specific expression, and serum marker levels. Results showed that T-2 toxin treatment resulted in a lower weight, volume, length, middle width, and middle circumference of the tibia in a dose-dependent manner (p < 0.05). Moreover, decreased bone-breaking strength, bone mineral density, and contents of ash, Ca, and P in the tibia were observed in T-2 toxin-challenged goslings (p < 0.05). In addition, T-2 toxin not only reduced TGP height (p < 0.05) but also induced TGP chondrocytes to be disorganized with reduced numbers and indistinct borders. As expected, the apoptosis-related genes (CASP9 and CASP3) were significantly up-regulated in chondrocytes challenged by T-2 toxin with a dose dependence, while cell differentiation and maturation-related genes (BMP6, BMP7, SOX9, and RUNX2) were down-regulated (p < 0.05). Considering bone metabolism, T-2 toxin dose-dependently and significantly induced a decreased number of osteoblasts and an increased number of osteoclasts in the tibia, with inhibited patterns of osteogenesis-related genes and enzymes and increased patterns of osteoclast-related genes and enzymes (p < 0.05). Similarly, the serum Ca and P concentrations and parathyroid hormone, calcitonin, and 1, 25-dihydroxycholecalciferol levels decreased under T-2 toxin exposure (p < 0.05). In summary, 2.0 mg/kg T-2 toxin significantly inhibited tibia weight, length, width, and circumference, as well as decreased bone-breaking strength, density, and composition (ash, calcium, and phosphorus) in 21-day-old goslings compared to the control and lower dose groups. Chondrocyte differentiation in TGP was delayed by 2.0 mg/kg T-2 toxin owing to cell apoptosis. In addition, 2.0 mg/kg T-2 toxin promoted bone resorption and inhibited osteogenesis in cellular morphology, gene expression, and hormonal modulation patterns. Thus, T-2 toxin significantly inhibited tibial growth and development with a dose dependence, accompanied by decreased bone geometry parameters and properties, hindered chondrocyte differentiation, and imbalanced bone metabolism.

Investigation of the Zero-Frequency Component of Nonlinear Lamb Waves in a Symmetrical Undulated Plate.

When an ultrasonic pulse propagates in a thin plate, nonlinear Lamb waves with higher harmonics and a zero-frequency component (ZFC) will be generated because of the nonlinearity of materials. The ZFC, also known as the static displacement or static component, has its unique application on the evaluation of early-stage damages in the elastic symmetrical undulated plate. In this study, analysis of the excitation mechanism of the ZFC and the second harmonic component (SHC) was theoretically and numerically investigated, and the material early-stage damage of a symmetrical undulated was characterized by studying the propagation of nonlinear Lamb waves. Both the ZFC and SHC can be effectively employed in monitoring the material damages of the undulated plate in its early stage. However, several factors must be considered for the propagation of the SHC in an undulated plate because of the geometric curvature and interference between the second harmonics during propagation, preventing efficient application of this technique. If the fundamental wave can propagate in the plate regardless of the plate boundary conditions, an accumulative effect always exists for the ZFC in a thin plate, indicating that the ZFC is independent of the structural geometry. This study reveals that the ZFC-based inspection technique is more efficient and powerful in characterizing the damages of a symmetrical undulated plate in the early stage of service compared to the second harmonic method.