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Naturally derived protein-based biopolymers are considered potential biomaterials in biomedical applications and eco-friendly materials for replacing current petroleum-based polymers due to their good biocompatibility, low environmental impact, and tunable degradability. However, current strategies for fabricating protein-based materials with superior properties and tailored functionality in a scalable manner are still lacking. Here, we demonstrate an aqueous-based scalable approach for fabricating silk protein-based films through controlled molecular self-assembly (CMS) of silk proteins with plasticizers and salt ions. The films fabricated using this method can achieve a toughness of up to 64±5 MJ/m

Traumatic heterotopic ossification (HO) refers to the abnormal ectopic osteogenesis following trauma, causing limb dysfunction and seriously lowering the life quality of patients. Aberrant osteogenic behavior of progenitor cells that ectopically accumulated within the soft tissues are believed to be responsible for HO formation. However, the detailed mechanism still remained to be clarified. Here in this study, we successfully isolated osteoprogenitors from human heterotopic ossification tissues (HO-ops) and identified their stemness and multi-directional differentiation potential. Using alkaline phosphatase staining together with alizarin red staining, we confirmed that the HO-ops in the heterotopic ossified tissues gained greater osteogenic potential than the normal human bone marrow mesenchymal stem cells (HBMSCs). RT-qPCR also indicated that HO-ops obtained more gene transcriptions of critical osteogenic determinators than HBMSCs. In addition, through Western blot, we proved that ERK signaling pathway and hedgehog signaling pathway were significantly activated in the HO-ops. When U0126 and cyclopamine were used to inhibit ERK signaling and hedgehog signaling respectively, the osteogenic potential of HO-ops decreased significantly. The hedgehog signaling and ERK signaling also showed cross-talk in HO-ops during osteogenic differentiation in HO-ops during osteogenic differentiation. The elevated ERK signaling and hedgehog signaling were further confirmed in the human traumatic HO sample sections by immunohistochemical staining. In sum, our results showed that the activation of ERK and hedgehog signaling pathway jointly enhanced the osteogenic potential of HO-ops to induce the formation of traumatic HO, which provides novel insights into the molecular basis of HO formation and offers promising targets for future therapeutic strategy.

There are limited naturally derived protein biomaterials for the available medical implants. High cost, low yield, and batch-to-batch inconsistency, as well as intrinsically differing bioactivity in some of the proteins, make them less beneficial as common implant materials compared to their synthetic counterparts. Here, we present a milk-derived whey protein isolate (WPI) as a new kind of natural protein-based biomaterial for medical implants. The WPI was methacrylated at 100 g bench scale,95% conversion, and 90% yield to generate a photo-cross-linkable material. WPI-MA was further processed into injectable hydrogels, monodispersed microspheres, and patterned scaffolds with photo-cross-linking-based advanced processing methods including microfluidics and 3D printing. In vivo evaluation of the WPI-MA hydrogels showed promising biocompatibility and degradability. Intramyocardial implantation of injectable WPI-MA hydrogels in a model of myocardial infarction attenuated the pathological changes in the left ventricle. Our results indicate a possible therapeutic value of WPI-based biomaterials and give rise to a potential collaboration between the dairy industry and the production of medical therapeutics.

Protein-based soft ionic conductors have attracted considerable research interest in recent years with great potential in applications at the human-machine interfaces. However, a fundamental mechanistic understanding of the ionic conductivity of silk-based ionic conductors is still unclear. Here, we first developed an environmental-friendly and scalable method to fabricate silk-based soft ionic conductors using silk proteins and calcium chloride. The mechanistic understanding of the ion transport and molecular interactions between calcium ions and silk proteins at variable water contents was investigated in-depth by combining experimental and simulation approaches. The results show that calcium ions primarily interact with amide groups in proteins at a low water content. The ionic conductivity is low since the calcium ions are confined around silk proteins within 2.0-2.6 Å. As water content increases, the calcium ions are hydrated with the formation of water shells, leading to the increased distance between calcium ions and silk proteins (3.3-6.0 Å). As a result, the motion of the calcium ions increased to achieve a higher ionic conductivity. By optimizing the ratio of the silk proteins, calcium ions, and water, silk-based soft ionic conductors with good stretchability and self-healing properties can be obtained. Such protein-based soft ionic conductors can be further used to fabricate smart devices such as electrochromic devices.

Background Open elbow arthrolysis (OEA), which has become an established treatment for post-traumatic elbow stiffness (PTES), requires complete release of contracture tissue and wide excision of ectopic bone, which results in extensive bleeding. The aim of the present study is to evaluate the efficacy of intravenous tranexamic acid (TXA) on postoperative drainage, calculated blood loss, and early clinical outcomes in patients undergoing OEA. Methods A double-blind, randomized, placebo-controlled trial including 96 patients undergoing OEA was undertaken. Patients received intravenously either 100 mL saline (placebo group, n = 48), or 100 mL saline plus 1 g TXA (TXA group, n = 48) before skin incision. The primary outcome was the drainage volume on postoperative days (PODs) 1-3. Secondary outcomes included the calculated blood loss, elbow pain score measured by visual analog scale (VAS), elbow function valued by Mayo Elbow Performance Score (MEPS), and rate of complications after OEA. Results Mean total postoperative drainage volume (TXA group: 182 mL vs. placebo group: 214 mL, P = .003) and mean calculated total blood loss (TXA group: 582 mL vs. placebo group: 657 mL, P = .004) were significantly lower in the TXA group. No transfusions were necessary in either group. Mean VAS pain scores in elbow motion showed marked differences between both groups on POD 1 (TXA: 5 vs. placebo: 6, P = .003) and POD 2 (TXA: 4 vs. placebo: 5, P = .023) but not in other postoperative time points. No differences were detected in complications, such as pin-related infection, hematoma, new or exacerbation of ulnar nerve symptoms, and recurrent heterotopic ossification. At the 6-month follow-up, no statistical differences were found between the 2 groups with respect to the elbow functions including range of motion, VAS score, and MEPS. Conclusion Intravenous administration of TXA significantly decreased the postoperative drainage volume and the total estimated blood loss and alleviated the elbow pain with motion during early postoperative days in patients undergoing OEA.

Aims Heterotopic ossification (HO) is a common complication after elbow trauma and can cause severe upper limb disability. Although multiple prognostic factors have been reported to be associated with the development of post-traumatic HO, no model has yet been able to combine these predictors more succinctly to convey prognostic information and medical measures to patients. Therefore, this study aimed to identify prognostic factors leading to the formation of HO after surgery for elbow trauma, and to establish and validate a nomogram to predict the probability of HO formation in such particular injuries. Methods This multicentre case-control study comprised 200 patients with post-traumatic elbow HO and 229 patients who had elbow trauma but without HO formation between July 2019 and December 2020. Features possibly associated with HO formation were obtained. The least absolute shrinkage and selection operator regression model was used to optimize feature selection. Multivariable logistic regression analysis was applied to build the new nomogram: the Shanghai post-Traumatic Elbow Heterotopic Ossification Prediction model (STEHOP). STEHOP was validated by concordance index (C-index) and calibration plot. Internal validation was conducted using bootstrapping validation. Results Male sex, obesity, open wound, dislocations, late definitive surgical treatment, and lack of use of non-steroidal anti-inflammatory drugs were identified as adverse predictors and incorporated to construct the STEHOP model. It displayed good discrimination with a C-index of 0.80 (95% confidence interval 0.75 to 0.84). A high C-index value of 0.77 could still be reached in the internal validation. The calibration plot showed good agreement between nomogram prediction and observed outcomes. Conclusion The newly developed STEHOP model is a valid and convenient instrument to predict HO formation after surgery for elbow trauma. It could assist clinicians in counselling patients regarding treatment expectations and therapeutic choices. Cite this article: Bone Joint J 2022;104-B(8):963–971.

AimsThis study aimed to determine the minimal detectable change (MDC), minimal clinically important difference (MCID), and substantial clinical benefit (SCB) under distribution- and anchor-based methods for the Mayo Elbow Performance Index (MEPI) and range of movement (ROM) after open elbow arthrolysis (OEA). We also assessed the proportion of patients who achieved MCID and SCB; and identified the factors associated with achieving MCID.MethodsA cohort of 265 patients treated by OEA were included. The MEPI and ROM were evaluated at baseline and at two-year follow-up. Distribution-based MDC was calculated with confidence intervals (CIs) reflecting 80% (MDC 80), 90% (MDC 90), and 95% (MDC 95) certainty, and MCID with changes from baseline to follow-up. Anchor-based MCID (anchored to somewhat satisfied) and SCB (very satisfied) were calculated using a five-level Likert satisfaction scale. Multivariate logistic regression of factors affecting MCID achievement was performed.ResultsThe MDC increased substantially based on selected CIs (MDC 80, MDC 90, and MDC 95), ranging from 5.0 to 7.6 points for the MEPI, and from 8.2° to 12.5° for ROM. The MCID of the MEPI were 8.3 points under distribution-based and 12.2 points under anchor-based methods; distribution- and anchor-based MCID of ROM were 14.1° and 25.0°. The SCB of the MEPI and ROM were 17.3 points and 43.4°, respectively. The proportion of the patients who attained anchor-based MCID for the MEPI and ROM were 74.0% and 94.7%, respectively; furthermore, 64.2% and 86.8% attained SCB. Non-dominant arm (p = 0.022), higher preoperative MEPI rating (p < 0.001), and postoperative visual analogue scale pain score (p < 0.001) were independent predictors of not achieving MCID for the MEPI, while atraumatic causes (p = 0.040) and higher preoperative ROM (p = 0.005) were independent risk factors for ROM.ConclusionIn patients undergoing OEA, the MCID for the increased MEPI is 12.2 points and 25° increased ROM. The SCB is 17.3 points and 43.3°, respectively. Future studies using the MEPI and ROM to assess OEA outcomes should report not only statistical significance but also clinical importance. Cite this article: Bone Joint J 2021;103-B(2):366–372.

Background: Open arthrolysis is used for treating elbow stiffness in adults. This study evaluated the midterm outcomes after open arthrolysis in children and adolescents with posttraumatic elbow stiffness. Methods: Data of 31 children and adolescents with posttraumatic elbow stiffness following open arthrolysis with or without hinged external fixation from 2010 to 2014 were retrospectively analyzed. Their mean age was 15 (range: 6 to 19) years. At baseline and the follow-up (>4 y), we evaluated the outcomes (range of motion and Mayo Elbow Performance Index) and postoperative complications (pain, ulnar nerve symptoms, infections, and instability) and analyzed the association between outcomes and clinical variables. Results: The Mayo Elbow Performance Index improved from 67.9 (range: 35 to 95 points) to 93.7 points (range: 65 to 100 points; P

IntroductionThere has no consensus on optimal management of carpal tunnel syndrome (CTS), the most common compression neuropathy. Conservative therapy is generally accepted as first-line intervention. Therapeutic ultrasound has been widely reported to be treatment beneficial in nerve regeneration and conduction, and further accelerate compression recovery. The purpose of this study is to investigate the effectiveness of therapeutic ultrasound for CTS treatment.Methods and analysisThis study protocol entails a three-arm, prospective, multicentre, randomised controlled trial. 162 eligible adult participants diagnosed with mild to moderate CTS by using criteria developed from a consensus survey by the UK Primary Care Rheumatology Society will be assigned to either (1) therapeutic ultrasound, (2) night splint or (3) therapeutic ultrasound +night splint (combined) group. Primary outcome will be difference in Symptom Severity Scale of Boston Carpal Tunnel Questionnaire (BCTQ-SSS) at 6-week between night splint and therapeutic ultrasound +night splint groups. Secondary outcomes include Functional Status Scale of BCTQ, sleep questionnaire for interrupted sleep, EuroQol-5D for general health, Hospital Anxiety and Depression Scale for mental status, Work Limitations Questionnaire-25 for functional limitations at work, Global Rating of Change for treatment success and recurrence rate, physical examination, electrophysiological and ultrasound parameters. Intention-to-treat analyses will be used.Ethics and disseminationEthics committees of all clinical centres have approved this study. The leading centre is Shanghai Sixth People’s Hospital, whose approval number is 2021-152. New versions with appropriate amendments will be submitted to the committee for further approval. Final results will be published in peer-reviewed journals and presented at local, national and international conferences.Trial registration numberChiCTR2100050701.

Aims The aim of this study was to develop and internally validate a prognostic nomogram to predict the probability of gaining a functional range of motion (ROM ≥ 120°) after open arthrolysis of the elbow in patients with post-traumatic stiffness of the elbow. Methods We developed the Shanghai Prediction Model for Elbow Stiffness Surgical Outcome (SPESSO) based on a dataset of 551 patients who underwent open arthrolysis of the elbow in four institutions. Demographic and clinical characteristics were collected from medical records. The least absolute shrinkage and selection operator regression model was used to optimize the selection of relevant features. Multivariable logistic regression analysis was used to build the SPESSO. Its prediction performance was evaluated using the concordance index (C-index) and a calibration graph. Internal validation was conducted using bootstrapping validation. Results BMI, the duration of stiffness, the preoperative ROM, the preoperative intensity of pain, and grade of post-traumatic osteoarthritis of the elbow were identified as predictors of outcome and incorporated to construct the nomogram. SPESSO displayed good discrimination with a C-index of 0.73 (95% confidence interval 0.64 to 0.81). A high C-index value of 0.70 could still be reached in the interval validation. The calibration graph showed good agreement between the nomogram prediction and the outcome. Conclusion The newly developed SPESSO is a valid and convenient model which can be used to predict the outcome of open arthrolysis of the elbow. It could assist clinicians in counselling patients regarding the choice and expectations of treatment. Cite this article: Bone Joint J 2022;104-B(4):486–494.

Post-traumatic elbow stiffness is a disabling condition that remains challenging for upper limb surgeons. Open elbow arthrolysis is commonly used for the treatment of stiff elbow when conservative therapy has failed. Multiple questions commonly arise from surgeons who deal with this disease. These include whether the patient has post-traumatic stiff elbow, how to evaluate the problem, when surgery is appropriate, how to perform an excellent arthrolysis, what the optimal postoperative rehabilitation is, and how to prevent or reduce the incidence of complications. Following these questions, this review provides an update and overview of post-traumatic elbow stiffness with respect to the diagnosis, preoperative evaluation, arthrolysis strategies, postoperative rehabilitation, and prevention of complications, aiming to provide a complete diagnosis and treatment path. Cite this article: Bone Joint Open 2020;1-9:576–584.

BACKGROUND Hyperuricemia is considered a risk factor for increased postoperative complications and adverse functional outcomes in a variety of orthopedic surgeries. The purpose of this retrospective study was to investigate the clinical efficacy of patients with different uric acid levels after elbow arthrolysis. METHODS The study included 131 patients with post-traumatic elbow stiffness who underwent arthrolysis between March 2014 and March 2016. All patients were divided into 4 groups based on the preoperative serum level of uric acid (UA). The quartile method was used for grouping patients, including 33 in Q1 (UA

A quadratic approximation method for the limit value of magnetic stiffness in a high temperature superconducting levitation system is presented. The levitation configuration discussed is that of a cylindrical permanent magnet (PM) placed above a coaxial high temperature superconductor (HTS). The magnetic levitation force between the PM and the HTS is gained based on Kim's critical model and Ampere circulation theorem. The central issue of magnetic stiffness associated with the hysteresis of levitation force is discussed. Firstly, To a given levitation gap between the PM and the HTS, the approximate values of magnetic stiffness is obtained corresponding to different displacement increments from 0.05 mm to 3 mm. In the first approximation the least square method is used for curve fitting force-displacement table. Secondly, the limit value of magnetic stiffness is gained at the zero displacement increment in the polynomial fitting curve of the first approximate values. The results show that the limit value of magnetic stiffness is dependent on the large levitation gap and the movement direction of the levitation object. The given displacement increments, such as 0.5 mm or 1 mm, are more suitable in superconducting levitation experiments. The difference between experiment data of magnetic stiffness and the limit ones is investigated.

ObjectiveHeterotopic ossification (HO) is a pathological bone formation process caused by musculoskeletal trauma. Our previous studies have indicated that macrophage inflammation is involved in traumatic HO formation. In this study, we validated the functional roles of M2 macrophages in HO.MethodsMacrophage Infiltration and activation of TGF-β/Smad2/3 signaling were examined in human HO tissues. By using a mice traumatic HO model, the effect of macrophages on HO progression was tested. Then the roles of angiogenesis and TGF-β signaling were elevated following macrophages depletion. Finally, the subtypes of macrophages were determined by FACS.ResultsWe found that macrophage infiltration and TGF-βsignaling activation are presented in human HO. Depletion of macrophages effectively suppressed traumatic HO formation in a mice model, and macrophage depletion significantly inhibited the activation of TGF-β/Smad2/3 signaling. In addition, the TGF-β blockade created by a neutralizing antibody impeded ectopic bone formation in vivo. Notably, endochondral ossification and angiogenesis are attenuated following macrophage depletion or TGF-β inhibition. Furthermore, our observations on macrophage polarization revealed that M2 macrophages, rather than M1 macrophages, play a critical role in supporting HO development by enhancing the osteogenic and chondrogenic differentiation of mesenchymal stem cells. ConclusionOur findings on ectopic bone formation in HO patients and the mice model indicate that M2 macrophages are an important contributor for HO development, and that inhibition of M2 polarization or TGF-β activity may be a potential method of therapy for traumatic HO.

Background: Impaired wound healing is one of the most noteworthy features and troublesome complications of diabetes mellitus, which arouses a rising global health concern without potent remedies. Thrombin is the major hemostatic agent applied at wound healing initiation and recently gained therapeutic credits in later phases. However, a rare investigation achieved prolonged use of thrombin and probed the detailed mechanism. Objective: The objective of this study is to investigate the effects and mechanism of thrombin on diabetic skin wound healing. Methods: The effect of thrombin on fibroblast proliferation, α-SMA, and Collagen I expression was firstly studied in vitro by Cell Counting Kit 8 (CCK8) and western blotting. Then, the specific phosphorylation site of SMAD2/3 and their ERK1/2 dependence during thrombin treatment were assessed by western blotting for mechanism exploration. After that, full-thickness wound defects were established in diabetic male SD rats and treated with thrombin in the presence or absence of PD98059 to observe the in vivo effects of thrombin and to confirm its ERK dependence. Results: We found that thrombin promoted fibroblast proliferation and their α-SMA and Collagen I production. Mechanistically, thrombin induced phosphorylation of Smad2 linker region (Ser245/250/255) through ERK1/2 phosphorylation but promoted phosphorylation of Smad3 linker region (Ser204) independent of ERK1/2. Histological results showed that thrombin facilitated wound healing by promoting α-SMA and Collagen I expression, which was not abolished by inhibiting ERK phosphorylation. Conclusion: Collectively, this study validated the therapeutic efficacy of thrombin on diabetic wound healing and identified both ERK-dependent and -independent Smad2/3 linker region phosphorylation as the essential signaling events in this process.

Joint stiffness is a common complication after articular-related trauma in the elbow, resulting in significant limb disability, psychological stress, and a negative impact on daily life. No previous study has reported the impact of post-traumatic elbow stiffness (PTES) on psychological health. This study aims to (1) investigate the depression and anxiety levels and (2) identify factors independently associated with depression and anxiety symptoms in patients with PTES.A total of 108 patients with PTES presenting to 4 collaborative municipal hospitals were consecutively enrolled from September to December 2020. Sociodemographic and clinical characteristics were collected through questionnaires and medical records. The Depression Anxiety Stress Scale-21 was used to assess depression and anxiety status. Ordinal logistic regression analysis was performed to identify factors independently associated with depression and anxiety symptoms.The detection rates of mild-to-moderate depression and anxiety are 40.7% and 27.8%, and severe-to-extremely severe levels are 23.1% and 25.9%, respectively. Regression results show that factors independently associated with depression include elbow flexion (odds ratio [OR]Patients with PTES exhibit significant depression and anxiety symptoms. Several sociodemographic and clinical characteristics are independently associated with depression and anxiety levels. Identifying and addressing these factors may be of particular benefit during PTES management. Future research might address whether depression and anxiety affect the outcome after stiff elbow surgery.

It remains unclear how the precise length of one-dimensional nanovehicles influences the characters of vaccination. Here, a unimolecular nanovehicle with tailored size and aspect ratio (AR) is applied to deliver CpG oligodeoxynucleotide, a Toll-like receptor (TLR) 9 agonist, as an adjuvant of recombinant hepatitis B virus surface antigen (rHBsAg), for treating chronic hepatitis B (CHB). Cationic nanovehicles with fixed width (ca. 45 nm) but varied length (46 nm-180 nm), AR from 1 to 4, are prepared through controlled polymerization and are loaded with CpG by electrostatic interaction. We reveal that the nanoadjuvant with AR = 2 shows the highest retention in proximal lymph nodes. Importantly, it is more easily internalized into antigen-presenting cells and accumulates in the late endosome, where TLR9 is located. Such a nanoadjuvant exhibits the strongest immune response with rHBsAg to clear the hepatitis B virus in the CHB mouse model, showing that the AR of nanovehicles governs the efficiency of vaccination.

Post-trauma elbow stiffness (PTES) is a common complication after elbow trauma that causes severe upper limb disability. Open elbow arthrolysis (OEA) with radial head arthroplasty (RHA) is an effective method to treat PTES with rotation limitation, or persistent pain/instability after radial head resection. However, no long-term results have been reported for this technique. This study aimed to show the clinical and radiographic outcomes of OEA with RHA over 8 years and compare its efficacy at 3 years (short-term).Patients with PTES treated by OEA with RHA between September 2010 and December 2012 were retrospectively reviewed. Seventeen patients were followed up over 8 years (range, 100-106 months). A bipolar prosthesis of RHA was performed during OEA. Preoperative, 3-year, and 8-year elbow and forearm motion, upper limb function, radiographic outcomes, and complications were recorded.Clinically important improvements in elbow motion and forearm rotation were obtained, from 34° and 58° preoperatively, to 109° and 135° at 3 years, which were maintained over 8 years, to 113° (P = .262) and 134° (P = .489). The Mayo Elbow Performance Index had clinically important increases from the preoperative level of 58 to 94 points at 3 years, and was maintained over 8 years (95 points, P = .422), with 100% reporting excellent to good outcomes. Pain and nerve symptoms were also improved. Complications consisted of new-onset ulnar nerve symptoms in 1 patient, nonclinically significant heterotopic ossification recurrence in 3, humeroulnar arthritis exacerbation in 4, and periprosthetic lucency in 8.OEA with RHA yielded satisfactory short-term outcomes for PTES at 3 years, with substantial improvements in elbow mobility and function, and the results were durable over the long term (8 years).

Inspired by the natural motors capable of performing multiple tasks in complex living environments, synthetic nanomotors emerge as a potential vehicle for revolutionizing biomedical processes. Yet current motors suffer from decreased and even completely hindered motion in a complex physiological environment, shadowing the future of this booming field. To address this problem, a unimolecular nanomotor based on molecular bottlebrush (MBB) of sub-100 nm size is reported. This motor is constructed precisely via controlled radical polymerization and click chemistry and propelled with biocompatible catalase. Such a molecular nanomotor possesses tadpole-like asymmetry and is able to overcome Brownian motion, and demonstrates strong directional propulsion (linear and coiled cyclic trajectories) in a viscous tumor microenvironment gel model at an ultralow hydrogen peroxide level of 2 mM (0.006%). In addition, the molecular nanomotor exhibits superior stability in serum containing cell medium and good biocompatibility in blood. Such molecular bottlebrush based nanomotors may represent a unique platform for overcoming the tissue penetration barrier.

Enhanced recovery after surgery (ERAS) protocols aim to improve perioperative outcomes and facilitate recovery for the patient through multimodal pathways. While implementation of ERAS has improved outcomes in numerous surgical specialties, benefits specific to elbow arthrolysis have not been investigated. The purpose of this study was to determine the effects of an evidence-based ERAS pathway on: (1) reducing pain intensity and postoperative complications compared to conventional care, and (2) improving range of motion (ROM) and function of the elbow after open arthrolysis.A randomized controlled study was performed between September 2017 and January 2018. Fifty patients with post-traumatic stiff elbow scheduled for surgery were randomly divided into ERAS group (25 patients) and conventional care group (25 patients). Duration of surgery, pre- and post-surgery ROM, Mayo Elbow Performance Score (MEPS), and visual analog scale (VAS) pain scores at rest and in motion were measured postoperatively at 1 through 5 days, 6-weeks, and 6-months. Complications were recorded 6-months postoperatively.VAS pain score values at rest and in motion in the ERAS group were consistently significantly lower than those in the conventional care group at 1 through 5 postoperatively days (P 0.05). At 6-weeks and 6-months after surgery, pain score values at rest and in motion were similar between the 2 groups (P 0.05). ROM was consistently significantly better in the ERAS group compared with the conventional care group (P 0.05). No significant differences in MEPS or complications were found between the 2 groups (P 0.05).ERAS pathway is feasible to implement in elbow arthrolysis and can result in clinically meaningful improvements in levels of pain (at rest and in motion) and ROM without an increase in the rate of postoperative complications.

Molecular bottlebrushes featuring brush-on-brush (BoB) architecture were prepared by combining azide-alkyne click chemistry, ring-opening polymerization (ROP), and atom transfer radical polymerization (ATRP). Primary side chains of diblock copolymers with a poly(ε-caprolactone) (PCL) block and a poly(α-bromo-ε-caprolactone) (P(CL-Br)) block were synthesized by ROP and then grafted onto PCL backbone by the click reaction. Then the secondary side chains of poly(oligo(ethylene glycol) acrylate) (POEGA) were grafted from the P(CL-Br) block by ATRP, yielding an amphiphilic core/shell structure. Imaging of individual macromolecules by atomic force microscopy (AFM) demonstrated dramatically thickened wormlike formation with distinct hairy side chains. Interestingly, for the BoB molecular bottlebrushes with enough long primary and secondary side chains, sufficient tension can be generated along the backbone and thus lead to its cleavage.

BACKGROUND: The elbow is more susceptible to loss of motion after trauma than any other joint. Open arthrolysis often is performed for posttraumatic elbow stiffness if the stiffness does not improve with nonsurgical treatment, but the midterm results of this procedure and factors that may limit recovery have not been widely studied. QUESTIONS/PURPOSES: We reviewed patients who had undergone open arthrolysis with hinged external fixator for severe posttraumatic elbow stiffness (ROM ≤ 60°) with a minimum of 5 years followup to (1) analyze ROM gains; (2) assess functional improvement with the Mayo Elbow Performance Index (MEPI) and DASH, quality of life with the SF-36, pain with VAS, and ulnar nerve function with the Amadio rating scale and Dellon classification; and (3) identify complications and risk factors that might hinder mid-term elbow motion recovery after this procedure. METHODS: Between March 2011 and December 2012, we generally offered patients with elbow stiffness an open arthrolysis procedure when function did not improve with 6 months of nonoperative therapy, and no contraindications such as immature heterotopic ossification or complete destruction of articular cartilage were present. During that time, 161 patients underwent open arthrolysis for posttraumatic elbow stiffness at our institution; 49 of them satisfied the study inclusion criteria (adults with elbow ROM ≤ 60° as a result of trauma) and exclusion criteria (stiffness caused by burns or central nervous system injuries, causative trauma associated with nonunion or malunion of the elbow, severe articular damage that would have necessitated joint arthroplasty, or prior elbow release). In general, a combined medial-lateral approach to the elbow was performed to address the soft tissue tethers and any blocks to elbow motion, and a hinged external fixator was applied for 6 weeks to maintain elbow stability and improve the efficacy of postoperative rehabilitation. These patients were evaluated retrospectively at a mean followup period of 69 months (range, 62–83 months), and demographics, disease characteristics, arthrolysis details, pre- and postoutcome measures as noted, and complications were recorded via an electronic database. Multivariate regression analysis was performed to identify factors associated with ROM recovery. RESULTS: At final followup, total ROM increased from a preoperative mean of 27 ± 20° to a postoperative mean of 131 ± 11° (mean difference, 104°; 95% CI, 98°–111°; p < 0.001), and 98% (48 of 49) of patients achieved a functional ROM of 30° to 130°. Improvements were also found in functional scores (MEPI: 54 ± 12 to 95 ± 7, mean difference, 41 points; DASH: 48 ± 17 to 8 ± 8, mean difference, 40 points; both p < 0.001), life quality (physical SF-36: 46 ± 11 to 81 ± 12, mean difference, 35 points; mental SF-36: 43 ± 14 to 80 ± 9, mean difference, 37 points; both p < .001), pain (VAS: 2.5 ± 2.4 to 0.4 ± 0.8; mean difference, 2.0 points; p < 0.001), and ulnar nerve function (Amadio score: 7.8 ± 1.9 to 8.4 ± 0.8; mean difference, 0.6 points; p = 0.004). A total of 18% (nine of 49 patients) developed complications, including new-onset or exacerbated nerve symptoms (four patients), recurrent heterotopic ossification (two patients), and pin-related infections (three patients). No patients underwent subsequent surgery for any of the above complications. Lastly, the medium-term ROM was divided into ROM ≤ 120° (n = 9) and ROM > 120° (n = 40). After controlling for potential confounding variables such as duration of stiffness and tobacco use, we found that tobacco use was the only independent risk factor examined (odds ratio, 9; 95% CI, 2–47; p = 0.009) associated with recovery of ROM. CONCLUSIONS: Satisfactory medium-term results were found for open arthrolysis with hinged external fixation with our protocol in patients who had severe posttraumatic elbow stiffness. Appropriate and sufficient releases of tethered soft tissues and correction of any blocks that affect elbow motion intraoperatively, a dedicated team approach, and an aggressive and systematic postoperative rehabilitation program are the core steps for this procedure. Additionally, the importance of preoperative discontinuation of tobacco use should be emphasized. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Using recently developed C–H insertion chemistry, a mild post-modification of polyethylene (PE), hyperbranched polyethylene (HBPE) and isotactic polypropylene (iPP) to insert phenylsulfonyl groups was performed. The Michael-type radical addition applies 2-chloroanthroquinone (2-CIAQ) as a C–H bond-cleaving photocatalyst and 1,1-bis(phenylsulfonyl)ethylene (BPSE) as the olefinic substrate. The reactions were performed in solution with various feed ratios and the products were characterized by multi-instrumental analysis. The modification is a convenient one-step introduction of aromatic moieties along polyolefin chains. By optimization of the reaction conditions, as many as 18.5 graft units of BPSE were introduced per 100 ethylene repeating units. The modified samples were successfully demonstrated to act as a compatibilizer between blends of PE/iPP and polystyrene (PS) as verified by scanning electron microscopy (SEM).

The acquisition of good surface electromyography (sEMG) is an important prerequisite for correct and timely control of prosthetic limb movements. sEMG is nonlinear, nonstationary, and vulnerable against noise and a new sEMG denoising method using ensemble empirical mode decomposition (EEMD) and wavelet threshold is hence proposed to remove the random noise from the sEMG signal. With this method, the noised sEMG signal is first decomposed into several intrinsic mode functions (IMFs) by EEMD. The first IMF is mostly noise, coupled with a small useful component which is extracted using a wavelet transform based method by defining a peak-to-sum ratio and a noise-independent extracting threshold function. Other IMFs are processed using an improved wavelet threshold denoising method, where a noise variance estimation algorithm and an improved wavelet threshold function are combined. Key to the threshold denoising method, a threshold function is used to retain the required wavelet coefficients. Our denoising algorithm is tested for different sEMG signals produced by different muscles and motions. Experimental results show that the proposed new method performs better than other methods including the conventional wavelet threshold method and the EMD method, which guaranteed its usability in prosthetic limb control.

Evidence on the efficacy and safety of periarticular multimodal drug injection (PMDI) in open elbow arthrolysis (OEA) is limited. This study aimed to investigate differences in postoperative pain, blood loss, and range of motion (ROM) between PMDI vs. no injection among patients undergoing OEA, and the presence of PMDI-related complications.This prospective, double-blind randomized controlled trial included 59 patients who underwent OEA. Patients randomly received PMDI (ropivacaine, epinephrine, ketoprofen) before wound closure or no injection. The primary outcomes were elbow pain over the first postoperative week at rest and during motion, measured using the visual analog scale (VAS). VAS scores were compared to attain the 20-mm threshold values for a minimum clinically important difference. Parecoxib consumption on OEA night and postoperative days (PODs) 1-3 and total consumption during the first postoperative week were recorded. Blood loss was recorded every 24 hours until POD 3. ROM during rehabilitation was measured daily from day 1 to day 7 after surgery, as well as at 3-month follow-up. Medication-related side effects were recorded prospectively.The mean VAS score showed clinically important differences between PMDI and control groups at rest on OEA night (mean difference [MD], 25 mm; P.001) and first 3 PODs with motion (POD 1: MD, 28 mm, P.001; POD 2: MD, 21 mm, P.001; POD 3: MD, 21 mm, P.001) but not in other postoperative assessments. Parecoxib consumption was lower in the PMDI group on OEA night and PODs 1-3. Total parecoxib consumption during the first postoperative week was lower in the PMDI group vs. the control group (MD, 148 mg; P.001). Blood drainage was less in the PMDI group vs. the control group on POD 1 (MD, 38 mL; P = .016) but not on POD 2 (P = .950), POD 3 (P = .259), or total (P = .184). The PMDI group exhibited significantly better ROM during the first 4 PODs than the control group, whereas there was no difference at 3-month follow-up. No medication-related side effects were noted in the PMDI group.PMDI effectively relieves pain and reduces analgesic consumption for OEA patients, without an apparent increase in risks.