Postoperative laboratory testing in the era of outpatient total joint arthroplasty: Targeted patient selection and associated cost savings.

Background: With the advent of outpatient total joint arthroplasty (TJA), the days of routinely drawing postoperative labs (complete blood counts [CBCs] and metabolic panels [CMPs/BMPs]) to monitor for complications are behind us. However, there does exist a subset of at-risk patients that may benefit from diligent postoperative monitoring, though the circumstances under which labs should be ordered remains unclear and subject to surgeon discretion. A systematic review of the literature was therefore conducted to evaluate the utility of postoperative laboratory testing, approaches to targeted patient selection and associated cost-savings. Methods: The PubMed, MEDLINE, EBSCOhost, and Google Scholar electronic databases were searched on August 17, 2023, to identify all studies published since January 1, 2000, that evaluated the role of postoperative lab testing in TJA. (PROSPERO study protocol registration: CRD42023437334). Articles were included if a full-text English manuscript was available and the study assessed the utility of routine postoperative labs in TJA. 19 studies were included comprising 34,166 procedures. The mean Methodological index for Nonrandomized Studies score was 18.2 ± 1.5. Results: Abnormal postoperative lab results were common and infrequently required clinical intervention. Among several identified risk factors for patients that may benefit from postoperative laboratory monitoring, preoperative lab values proved excellent discriminators of transfusion requirement and metabolite-associated intervention. Selective testing demonstrated the ability to generate substantial cost-savings. Conclusion: Routine postoperative laboratory testing offers little clinical utility and produces unnecessary expenditures. Preoperative lab values offer the greatest predictive utility for postoperative transfusion requirement and metabolite-associated clinical intervention, with a preoperative hemoglobin threshold of 111.5 g/L offering an area under the curve (AUC) of 0.93 for predicting postoperative transfusion. Further investigations are needed for metabolic panel predictive models and should incorporate preoperative lab values. The refinement of such models can enable targeted patient selection to avoid unnecessary labs and generate substantial cost savings without compromising patient safety.

A finite element analysis of patellofemoral joint biomechanics: Exploring potential causes of postoperative anterior knee pain following unicompartmental knee arthroplasty.

Purpose: Anterior knee pain is a common complication following unicompartmental knee arthroplasty (UKA). This study aimed to elucidate the mechanism of anterior knee pain after UKA by examining the biomechanical characteristics of the patellofemoral joint. Methods: This study employs the finite element analysis method. A healthy model of the right lower limb was created using CT scans of an intact right lower limb from a healthy woman. Based on this model, a preoperative pathological model was generated by removing the meniscus and part of the articular cartilage. The UKA prosthesis was then applied to this model with five different bearing thicknesses: 5 mm, 7 mm, 10 mm, 11 mm, and 13 mm. To simulate various degrees of knee joint flexion, the femur was rotated relative to the knee joint's rotational axis, producing lower limb models at flexion angles of 0°, 30°, 60°, 90°, and 120°. We applied a constant force from the center of the femoral head to the center of the ankle joint to simulate lower limb loading during squatting. The simulations were conducted using Ansys 17.0. Results: Both overstuffing and understuffing increased the peak stress on the patellar cartilage, with overstuffing having a more pronounced effect. Compared to healthy and balanced models, overstuffed and understuffed models exhibited abnormal stress distribution and stress concentration in the patellar cartilage during knee flexion. Conclusion: Overstuffing and understuffing lead to residual varus or valgus deformities after UKA, causing mechanical abnormalities in the patellofemoral joint. These abnormalities, characterized by irregular stress distribution and excessive stress, result in cartilage damage, exacerbate wear in the patellofemoral joint and consequently lead to the occurrence of anterior knee pain.

A joint analysis proposal of nonlinear longitudinal and time-to-event right-, interval-censored data for modeling pregnancy miscarriage.

Pregnancy in-vitro fertilization (IVF) cases are associated with adverse first-trimester outcomes in comparison to spontaneously achieved pregnancies. Human chorionic gonadotrophin ß subunit (ß-HCG) is a well-known biomarker for the diagnosis and monitoring of pregnancy after IVF. Low levels of ß-HCG during this period are related to miscarriage, ectopic pregnancy, and IVF procedure failures. Longitudinal profiles of ß-HCG can be used to distinguish between normal and abnormal pregnancies and to assist and guide the clinician in better management and monitoring of post-IVF pregnancies. Therefore, assessing the association between longitudinally measured ß-HCG serum concentration and time to early miscarriage is of crucial interest to clinicians. A common joint modeling approach is to use the longitudinal ß-HCG trajectory to determine the risk of miscarriage. This work was motivated by a follow-up study with normal and abnormal pregnancies where ß-HCG serum concentrations were measured in 173 young women during a gestational age of 9-86 days in Santiago, Chile. Some women experienced a miscarriage event, and their exact event times were unknown, so we have interval-censored data, with the event occurring between the last time of the observed measurement and ten days later. However, for those women belonging to the normal pregnancy group; that is, carrying a pregnancy to a full-term event, right censoring data are observed. Estimation procedures are based on the Stochastic Approximation of the Expectation-Maximization (SAEM) algorithm.

Sensorimotor control of functional joint stability: Scientific concepts, clinical considerations, and the articuloneuromuscular cascade paradigm in peripheral joint injury.

Human movement depends on sensorimotor control. Sensorimotor control refers to central nervous system (CNS) control of joint stability, posture, and movement, all of which are effected via the sensorimotor system. Given the nervous, muscular, and skeletal systems function as an integrated "neuromusculoskeletal system" for the purpose of executing movement, musculoskeletal conditions can result in a cascade of impairments that affect negatively all three systems. The purpose of this article is to revisit concepts in joint stability, sensorimotor control of functional joint stability (FJS), joint instability, and sensorimotor impairments contributing to functional joint instability. This article differs from historical work because it updates previous models of joint injury and joint instability by incorporating more recent research on CNS factors, skeletal muscle factors, and tendon factors. The new 'articuloneuromuscular cascade paradigm' presented here offers a framework for facilitating further investigation into physiological and biomechanical consequences of joint injury and, in turn, how these follow on to affect physical activity (functional) capability. Here, the term 'injury' represents traumatic joint injury with a focus is on peripheral joint injury. Understanding the configuration of the sensorimotor system and the cascade of post-injury sensorimotor impairments is particularly important for clinicians reasoning rational interventions for patients with mechanical instability and functional instability. Concurrently, neurocognitive processing and neurocognitive performance are also addressed relative to feedforward neuromuscular control of FJS. This article offers itself as an educational resource and scientific asset to contribute to the ongoing research and applied practice journey for developing optimal peripheral joint injury rehabilitation strategies.

A Case of Severe Acute Kidney Injury Due to an Antibiotic-Loaded Cement Spacer for Infected Knee Arthroplasty.

The treatment for periprosthetic joint infection frequently involves the placement of a high-dose antibiotic-loaded bone cement spacer (ALCS) into the debrided joint. Typical antibiotics in the spacer include aminoglycosides and vancomycin. It has been believed that systemic absorption of intraarticular antibiotics would be low and early experience suggested that the risk of acute kidney injury (AKI) from ALCS was minimal. However, recent case reports and case series have suggested a risk of acute kidney injury due to antibiotic absorption, though confounding factors are common. We report a case of severe AKI requiring hemodialysis with extremely high systemic tobramycin levels after the placement of an ALCS with increased dosing of antibiotics after previous failure to resolve a periprosthetic joint infection with a prior ALCS. There was no concomitant use of intravenous nephrotoxic antibiotics nor other confounding factors. Despite dialysis, the patient needed urgent removal of the ALCS to control tobramycin levels with subsequent resolution of the AKI. This case highlights the potentially serious nephrotoxicity of ALCS's, the importance of antibiotic type and dosing, and the value of close monitoring after ALCS placement, especially in a patient with chronic kidney disease.

Type V Collagen Exhibits Distinct Regulatory Activities in TMJ Articular Disc versus Condylar Cartilage During Postnatal Growth and Remodeling.

Understanding matrix molecular activities that regulate the postnatal growth and remodeling of temporomandibular joint (TMJ) condylar cartilage and articular disc will enable the development of effective regenerative strategies targeting TMJ disorder. This study elucidated the distinct roles of type V collagen (collagen V) in regulating these two units. Studying the TMJ of young adult Col5a1+/- mice, we found loss of collagen V resulted in substantial changes in the proliferation, clustering, and density of progenitors in condylar cartilage, but did not have a major impact on disc cells that are more fibroblast-like. Although loss of collagen V led to thickened collagen fibrils with increased heterogeneity in the disc, there were no significant changes in local micromodulus except for a reduction at the posterior end of the inferior side. Following the induction of aberrant occlusal loading by the unilateral anterior crossbite (UAC) procedure, both wild-type (WT) and Col5a1+/- condylar cartilage exhibited salient remodeling, and Col5a1+/- condyle developed more pronounced degeneration and hypertrophy at the posterior end than the WT. In contrast, neither UAC nor collagen V deficiency induced marked changes in the morphology or mechanical properties of the disc. Together, our findings highlight the distinct roles of collagen V in regulating these two units during postnatal growth and remodeling, emphasizing its more crucial role in condylar cartilage due to its impact on the highly mechanosensitive progenitors. Results thus provide the foundation for using collagen V to improve the regeneration of TMJ and the care of patients with TMJ disorder. STATEMENT OF SIGNIFICANCE: Successful regeneration of temporomandibular joint (TMJ) condylar cartilage and articular disc remains a significant challenge due to the limited understanding of matrix molecular activities that regulate the formation and remodeling of these tissues. This study demonstrates that collagen V plays distinct and critical roles in these processes. In condylar cartilage, collagen V is essential for regulating progenitor cell fate and maintaining matrix integrity. In the disc, collagen V also regulates fibril structure and local micromechanics, but has a limited impact on cell phenotype or its remodeling response. Our findings establish collagen V as a key component in maintaining the integrity of these two units, with a more crucial role in condylar cartilage due to its impact on progenitor cell activities.

A systematic review on how to diagnose deltoid ligament injuries-are we missing a uniform standard?

BACKGROUND: Up to now, there is no convincing evidence, that surgical treatment of deltoid ligament injuries, especially in the setting of ankle fractures, does result in improved outcome. One reason could be a missing diagnostic standard. The aim of the current systematic review was to analyze the applied diagnostic strategies for acute deltoid ligament injuries in outcome studies. METHODS: MEDLINE, Scopus, Central, and EMBASE were searched through February 2022 for any original studies addressing diagnostics of acute deltoid injuries. The study was conducted per the PRISMA guidelines. The inclusion criteria were formed according to the PICOS criteria. The data assessed were study type, level of evidence, included fractures, time point and method of diagnosing deltoid ligament layers, differentiation between layers and syndesmotic injuries. RESULTS: 31 studies were included in the final analysis. Most studies (n = 28) based their decision to treat the deltoid ligament injury on radiologic findings only, with stressed radiographs (n = 18) being the most common. The radiographs were applied at one or more time points (preoperative, before ORIF, after ORIF, after ORIF and syndesmotic repair). The most frequently assessed parameter was the Medial Clear Space (MCS, n = 27) with cut-off-values considered pathological ranging between MCS > 1 mm and MCS > 6 mm. CONCLUSION: Comparing the 31 studies shows that a standardized method to diagnose deltoid ligament injuries is missing. Further research is needed to establish evidence-based guidelines on how to diagnose acute deltoid ligament injuries. TRIAL REGISTRATION: Prospero ID: CRD42022307112. CLINICAL TRIAL NUMBER: not applicable.

Adult Tillaux-Chaput tubercle fracture of the ankle with rupture of the peroneus tertius muscle: a case report.

BACKGROUND: Tillaux-Chaput tubercle fractures occur in adolescents, which are often associated with the separation of the distal tibial growth plate. These types of fractures are rare in adults and even rarer when accompanied by a rupture of the peroneus tertius muscle. Given the limited number of reported cases, there is limited clinical awareness, resulting in missed diagnoses and delayed treatment, ultimately affecting ankle function. CASE PRESENTATION: We report a case of an adult patient who experienced a right ankle injury resulting in swelling and pain after a traffic accident. Initial examination failed to identify the rupture of the peroneus tertius muscle, but the patient was observed to have restricted dorsiflexion and eversion of the foot. Surgical exploration through an anterolateral incision confirmed the rupture and the muscle was then repaired. The patient received four weeks of cast immobilization and then engaged in progressive rehabilitation exercises. DISCUSSION AND CONCLUSION: This report shares the diagnostic and therapeutic experiences of an adult with a Tillaux-Chaput tubercle fracture associated with peroneus tertius muscle rupture to improve clinical recognition of such injuries, thus preventing misdiagnosis and treatment delays.

The Impact of Muscle Energy Techniques on the Temporomandibular Motions Following Extraction Surgery of the Third Molar Tooth: A Randomised Clinical Trial.

BACKGROUND: Trismus and subsequent restricted range of motion in the temporomandibular joint may impede vital activities of daily living. OBJECTIVE: The primary purpose of the current study was to explore the impact of muscle energy techniques on the range of temporomandibular motions in individuals with trismus and restricted range of the temporomandibular motions after third molar extraction surgery. METHODS: Eligible volunteers were randomly assigned to either the intervention or control group. Participants in the intervention group received muscle energy techniques over seven consecutive postoperative days, while those in the control group did not receive any intervention. Both groups adhered to the recommended postoperative healthcare protocol provided by a single dentist. The range of cardinal and linear intra-articular motions of the temporomandibular joint was assessed on the first, second and seventh postoperative days in each group using a vernier calliper and an ultrasound machine, respectively. RESULTS: The range of linear intra-articular motion (p-value < 0.001) and cardinal motion (p-value < 0.032) of the TMJ significantly increased within groups after the first postoperative week. The range of temporomandibular motions, except for the forward displacement of the mandibular condyle (p-value = 0.193), and the range of mandibular retrusion (p-value = 0.339) exhibited a significant difference between groups (p-value < 0.017) after the first postoperative week. CONCLUSION: The current study revealed, for the first time, that muscle energy techniques increase the range of cardinal and linear intra-articular motions in individuals with trismus and restricted range of the temporomandibular motions following third molar extraction surgery. TRIAL REGISTRATION: Clinical Trials: IRCT20211016052783N1.

Biomechanical Study of Atlanto-occipital Instability in Type II Basilar Invagination: A Finite Element Analysis.

OBJECTIVE: Recent studies indicate that 3 morphological types of atlanto-occipital joint (AOJ) exist in the craniovertebral junction and are associated with type II basilar invagination (BI) and atlanto-occipital instability. However, the actual biomechanical effects remain unclear. This study aims to investigate biomechanical differences among AOJ types I, II, and III, and provide further evidence of atlanto-occipital instability in type II BI. METHODS: Models of bilateral AOJ containing various AOJ types were created, including I-I, I-II, II-II, II-III, and III-III models, with increasing AOJ dysplasia across models. Then, 1.5 Nm torque simulated cervical motions. The range of motion (ROM), ligament and joint stress, and basion-dental interval (BDI) were analyzed. RESULTS: The C0-1 ROM and accompanying rotational ROM increased progressively from model I-I to model III-III, with the ROM of model III-III showing increases between 27.3% and 123.8% indicating ultra-mobility and instability. In contrast, the C1-2 ROM changes were minimal. Meanwhile, the stress distribution pattern was disrupted; in particular, the C1 superior facet stress was concentrated centrally and decreased substantially across the models. The stress on the C0-1 capsule ligament decreased during cervical flexion and increased during bending and rotating loading. In addition, BDI gradually decreased across the models. Further analysis revealed that the dens showed an increase of 110.1% superiorly and 11.4% posteriorly, indicating an increased risk of spinal cord impingement. CONCLUSION: Progressive AOJ incongruity critically disrupts supportive tissue loading, enabling incremental atlanto-occipital instability. AOJ dysplasia plays a key biomechanical role in the pathogenesis of type II BI.

Effects of Parallax and Distortion in Total Ankle Arthroplasty.

BACKGROUND: Surgeons rely on intraoperative fluoroscopy to assist in placement of implant components during total ankle arthroplasty (TAA). Parallax alters the direction of an object when viewed from two different points, resulting in image distortion. The purpose of this study was to evaluate parallax/distortion in intraoperative fluoroscopic images during TAA. METHODS: A retrospective review of all TAAs performed by two surgeons (R.W.M. and B.S.) from August 2019 to April 2023 were reviewed. Intraoperative fluoroscopic anteroposterior (AP) ankle views were evaluated for any obvious parallax image distortion. Cases with obvious parallax distortion were included for angular evaluation of AP intraoperative fluoroscopic and first postoperative plain films. The tibia was marked at 2-centimeter intervals to create zones from the proximal stem of the implant. The anatomical axis of the tibia (AAT) was drawn at the mid-diaphysis. The anatomic lateral distal tibial angle (aLDTA) and anatomic axis deviation (AAD) were measured for each zone. RESULTS: A total of 22 TAAs were performed during the study period. Four cases were excluded due to inadequate imaging, leaving a total of 18 TAAs for review. We found 6 of 18 (33.3%) cases had obvious parallax distortion. We found the average aLDTA was 90.9° (84°-101°). At the most proximal tibial zone, the average aLDTA was 94° (91°-101°). We found the average AAD was 4.7 (0.5-17.2) mm. The AAD ranged from 0.5 to 17.2 mm lateral to 0.8 to 8.2 mm medial. Postoperative plain film radiographs displayed a normal aLDTA and an AAT centered within the ankle joint. CONCLUSION: Parallax can distort the appearance of the tibia on fluoroscopic images. Deviation from the normal aLDTA and anatomical axis should be anticipated. Surgeons should be aware of the potential impact of parallax and ways to mitigate these effects.

The effects of environments and adhesive layer thickness on the failure modes of composite material bonded joints.

In this study, a structural adhesive was used to bond unidirectional prepreg and fiber fabric in a single lap joint. The mechanical properties of the structural adhesive were investigated under room temperature dry state (RTD) and elevated temperature wet state (ETW, 71 â„ƒ/85% RH), and different adhesive layer thicknesses (0.5 mm, 1.0 mm, 1.5 mm, and 2.0 mm). The fracture surfaces of the bonded joints were examined using scanning electron microscopy (SEM), and finite element simulations were conducted to observe the failure modes and failure paths. Additionally, the specimens were immersed in water and hydraulic oil, and their tensile shear strength was tested to evaluate their liquid sensitivity. The experimental results indicated that with increasing adhesive layer thickness, the strength of the specimens decreased by 21% in the RTD and by 52% in the ETW. The strength differences between different environments were minimal for adhesive layer thicknesses of 1 mm and 1.5 mm. The shear strength of the specimens decreased after immersion in water and hydraulic oil, with reductions of 43.78% and 39.21%, compared to the room temperature dry respectively. SEM observations of the bonded joint sections revealed that the primary failure modes were adherend failure and adhesive layer failure. Finite element simulations indicated that fiber tearing and crack initiation occurred in stress concentration areas during loading, leading to structural failure.

Correlation of the single-segment dynamic stabilization with different segmental mobility and zygapophysial (facet) joint degeneration: a retrospective study in northern China.

OBJECTIVE: To compare the clinical and radiographic outcomes of single-segment posterior decompression combined with two different non-fusion dynamic stabilization systems, Isobar EVO and Isobar TTL, in the context of facet joint degeneration and segmental mobility. METHOD: A retrospective study was conducted on 47 patients who underwent single-segment surgery at the L4/5 level using either the Isobar EVO (n = 23) or Isobar TTL (n = 24) systems. We assessed facet joint degeneration on both sides of the fixed (L3/4, L4/5) and superior adjacent (L2/3) segments using the Fujiwara MRI grading system. Clinical outcomes were evaluated using the Oswestry Disability Index (ODI) and visual analog scale (VAS) for back and leg pain at baseline, 12 months, and 24 months postoperatively. RESULT: Both groups exhibited significant facet joint degeneration at the fixed segments (L3/4 and L4/5) at 24 months. The TTL group also showed significant degeneration at the superior adjacent segment (L2/3), whereas the EVO group did not. Restoration of lumbar lordosis was significantly better in the EVO group. Pain and disability scores improved more in the EVO group than in the TTL group at both 12 and 24 months postoperatively. CONCLUSION: The Isobar EVO system, with its enhanced mobility, may delay facet joint degeneration in the superior adjacent segment compared to the Isobar TTL system. However, both systems result in degeneration at the fixed segment, indicating a need for further improvements to mimic the natural biomechanics of the spine more closely.

Impact of whole-body vibration training on ankle joint proprioception and balance in stroke patients: a prospective cohort study.

BACKGROUND: Although whole-body vibration (WBV) training is acknowledged for its benefits in enhancing motor functions across several neurological disorders, its precise influence on ankle joint proprioception and balance in stroke patients is still not well understood. This research seeks to assess the impact of WBV training on ankle joint proprioception and balance in stroke patients, thereby filling this important research void. METHODS: In this prospective cohort study, thirty-five stroke patients were randomly assigned to either the WBV group (n = 17) or a control group (n = 18) using a random number table method. The control group received daily general rehabilitation for four weeks, while the WBV group received an additional 30 min of WBV training each day with the Trunsan S110 Vibration Training System. Blinded outcome assessments were conducted at baseline and post-treatment, utilizing the Berg balance scale (BBS), Functional reach test (FRT), Romberg test length (RTL) and area (RTA), and completion rates of ankle joint dorsiflexion-plantar flexion (DP) and inversion-eversion (IE) tests. Follow-up assessments were performed after four weeks of intervention, focusing on RTL, RTA, DP, and IE as primary outcomes. RESULTS: Analysis of intra-group changes from baseline to post-treatment revealed significant improvements across the BBS, FRT, RTL, RTA, and DP and IE assessments (p < 0.001). Notably, the WBV group showed significant enhancements compared to the control group in DP and IE (p < 0.001 and p < 0.05, respectively), with mean values increasing from 13.556 to 16.765 (23.7%) and from 5.944 to 8.118 (36.6%), respectively. However, WBV did not provide additional benefits over the control treatment for balance recovery parameters such as BBS, FRT, RTL, and RTA (p > 0.05). CONCLUSIONS: This study demonstrates that WBV therapy is equally effective as conventional methods in enhancing proprioception and balance in stroke patients, but it does not provide additional benefits for balance recovery. WBV significantly improves proprioceptive functions, particularly in DP and IE parameters. However, it does not surpass traditional rehabilitation methods in terms of balance recovery. These findings indicate that WBV should be incorporated into stroke rehabilitation primarily to enhance proprioception rather than to optimize balance recovery. TRIAL REGISTRATION: This study was retrospectively registered in the ISRCTN Registry on 29/07/2024 ( https://www.isrctn.com/ , ISRCTN64602845).

Effect of pH and hydroxyapatite-like layer formation on the antibacterial properties of borophosphate bioactive glass incorporated poly(methyl methacrylate) bone cement.

Infection is a leading cause of total joint arthroplasty failure. Current preventative measures incorporate antibiotics into the poly (methyl methacrylate) (PMMA) bone cement that anchors the implant into the natural bone. With bacterial resistance to antibiotics on the rise, the development of alternative antibacterial materials is crucial to mitigate infection. Borate bioactive glass, 13-93-B3, has been studied previously for use in orthopedic applications due to its ability to be incorporated into bone cements and other scaffolds, convert into hydroxyapatite (HA)-like layer, and enhance the osseointegration and antibacterial properties of the material. The purpose of this study is to better understand how glass composition and change in surrounding pH effects the composite's antibacterial characteristics by comparing the incorporation of 30% wt/wt 13-93-B3 glass and pH neutral borophosphate bioactive glass into PMMA bone cement. We also aim to elucidate how HA-like layer formation on the cement's surface may affect bacterial adhesion. These studies showed that 13-93-B3 incorporated cements had significant reduction of bacterial growth surrounding the composite beyond 24 h of exposure when compared to a neutral borate bioactive glass incorporated cement (p < 0.01) and cement only (p < 0.0001). Additionally, through soaking cement composites in simulated body fluid and then exposing them to a bioluminescent strand of staphylococcus aureus, we found that the presence of a HA-like layer on the 13-93-B3 or pH neutral glass incorporated cement disks resulted in an increase in bacterial attachment on the composite cement's surface, where p < 0.001, and p < 0.05 respectively. Overall, our studies demonstrated that borate bioactive glass incorporated PMMA bone cement has innate antimicrobial properties that make it a promising material to prevent infection in total joint arthroplasties.

Characteristics of upper limb joint mechanics with increased cane dependence during walking.

[Purpose] This study investigated the effects of differences in cane dependence on the mechanical work at the shoulder, elbow, and wrist joints during walking. [Participants and Methods] Fifteen volunteers participated in this study (mean ± standard deviation [SD] age: 24.9 ± 2.7 years, height: 1.73 ± 0.04 m, and body mass: 68.5 ± 8.9 kg). The participants walked under three conditions: (1) without a cane, (2) with a cane at 10% body weight (BW), and (3) with a cane at 20% BW. The shoulder, elbow, and wrist joint work was calculated to evaluate the mechanical load. [Results] The results indicated a significant interaction between load conditions and positive joint work, as well as between load conditions and negative joint work. The positive work in the shoulder and elbow joints significantly increased in the 20% BW condition compared to that in the 10% BW condition. [Conclusion] Increased cane dependence did not uniformly increase the positive and negative work of the shoulder, elbow, and wrist joints. Increased cane dependence during walking increases energy generation in the shoulder and elbow joints, which can result in adverse musculoskeletal strain on the shoulder and elbow joints.

Evaluation of the review models and approval timelines of authorities participating in the East African Medicine Regulatory Harmonisation initiative: alignment and strategies for moving forward.

Introduction: Medicines regulatory harmonisation has been embraced by many national regulatory authorities (NRAs) to improve public health through faster availability of safe, high-quality, and effective medical products to patients and enhanced standardisation of technical guidelines and work sharing, leading to reduced cost to pharmaceutical companies. After ten years of implementing regulatory harmonisation by the East African Community Medicines Registration Harmonization (EAC-MRH) initiative, it is now imperative for participating NRAs to rely on each other to minimise duplication of use of limited resources. Major challenges in implementing reliance are the lack of clear registration processes and delays in the approval. The aim of this study was to compare review models, target timelines and data requirements used in assessing applications by EAC-MRH NRAs so as to align and propose strategies for improvement. Methods: A validated questionnaire that standardises and captures review processes was completed by the head of the medicine's registration division in each of the seven EAC-MRH NRAs. A country report based on the completed questionnaire was developed for each NRA and validated by the heads of the respective authorities. Results: Most applications received by all countries were for generics except Kenya, which received a significant number of new active substance applications (55 and 53 in 2020 and 2021). Mean approval times for generics using full review varied, with Tanzania's time declining for the three years. Target timelines for full review for the five countries ranged between 180 calendar days (Tanzania) to the highest 330 days (Zanzibar). The three countries (Kenya, Rwanda and Uganda) utilising the verification review model had a target timeline of 90 days. All six authorities conducted abridged reviews and fast-track assessments through a priority review track. The common technical document format was mandatory for applications in all authorities. The target timeline for key milestones in the review process varied for each country with a few similarities. Discussion: The study has provided a baseline for review models, target timelines and data requirements utilised in assessing applications for registration by EAC-MRH NRAs. Implementing the recommendations from this study will enable the NRAs to align and improve their registration processes.

Non-invasive regional parameter identification of degenerated human meniscus.

Accurate identification of local changes in the biomechanical properties of the normal and degenerative meniscus is critical to better understand knee joint osteoarthritis onset and progression. Ex-vivo material characterization is typically performed on specimens obtained from different locations, compromising the tissue's structural integrity and thus altering its mechanical behavior. Therefore, the aim of this in-silico study was to establish a non-invasive method to determine the region-specific material properties of the degenerated human meniscus. In a previous experimental magnetic resonance imaging (MRI) study, the spatial displacement of the meniscus and its root attachments in mildly degenerated (n = 12) and severely degenerated (n = 12) cadaveric knee joints was determined under controlled subject-specific axial joint loading. To simulate the experimental response of the lateral and medial menisci, individual finite element models were created utilizing a transverse isotropic hyper-poroelastic constitutive material formulation. The superficial displacements were applied to the individual models to calculate the femoral reaction force in an inverse finite element analysis. During particle swarm optimization, the four most sensitive material parameters were varied to minimize the error between the femoral reaction force and the force applied in the MRI loading experiment. Individual global and regional parameter sets were identified. In addition to in-depth model verification, prediction errors were determined to quantify the reliability of the identified parameter sets. Both compressibility of the solid meniscus matrix (+141 %, p ≤ 0.04) and hydraulic permeability (+53 %, p ≤ 0.04) were significantly increased in the menisci of severely degenerated knees compared to mildly degenerated knees, irrespective of the meniscus region. By contrast, tensile and shear properties were unaffected by progressive knee joint degeneration. Overall, the optimization procedure resulted in reliable and robust parameter sets, as evidenced by mean prediction errors of <1 %. In conclusion, the proposed approach demonstrated high potential for application in clinical practice, where it might provide a non-invasive diagnostic tool for the early detection of osteoarthritic changes within the knee joint.

Effects of helmet usage on moped riders' injury severity in moped-vehicle crashes: Insights from partially temporal constrained random parameters bivariate probit models.

Mopeds are small and move unpredictably, making them difficult for other drivers to perceive. This lack of visibility, coupled with the minimal protection that mopeds provide, can lead to serious crashes, particularly when the rider is not wearing a helmet. This paper explores the association between helmet usage and injury severity among moped riders involved in collisions with other vehicles. A series of joint bivariate probit models are employed, with injury severity and helmet usage serving as dependent variables. Data on two-vehicle moped crashes in Florida from 2019 to 2021 are collected and categorized into three periods: before, during, and after the COVID-19 pandemic. Crash involvement ratios are calculated to examine the safety risk elements of moped riders in various categories, while significant temporal shifts are also explored. The correlated joint random parameters bivariate probit models with heterogeneity in means demonstrate their superiority in capturing interactive unobserved heterogeneity, revealing how various variables significantly affect injury outcomes and helmet usage. Temporal instability related to the COVID-19 pandemic is validated through likelihood ratio tests, out-of-sample predictions, and calculations of marginal effects. Additionally, several parameters are noted to remain temporally stable across multiple periods, prompting the development of a partially temporally constrained modeling approach to provide insights from a long-term perspective. Specifically, it is found that male moped riders are less likely to wear helmets and are negatively associated with injury/fatality rates. Moped riders on two-lane roads are also less likely to wear helmets. Furthermore, moped riders face a lower risk of injury or fatality during daylight conditions, while angle crashes consistently lead to a higher risk of injuries and fatalities across the three periods. These findings provide valuable insights into helmet usage and injury severity among moped riders and offer guidance for developing countermeasures to protect them.

The assumed motor capabilities of a partner influence motor imagery in a joint serial disc transfer task.

Motor imagery (MI) of one's own movements is thought to involve the sub-threshold activation of one's own motor codes. Movement coordination during joint action is thought to occur because co-actors integrate a simulation of their own actions with the simulated actions of the partner. The present experiments gained insight into MI of joint action by investigating if and how the assumed motor capabilitiesof the imaginary partner affected MI. Participants performed a serial disc transfer task alone and then imagined performing the same task alone and with an imagined partner. In the individual tasks, participants transferred all four discs. In the joint task, participants imagined themselves transferring the first 2 discs and a partner transferring the last 2 discs. The description of the imagined partner (high/low performer) was manipulated across blocks to determine if participants adapted their MI of the joint task based on the partner's characteristics. Results revealed that imagined movement times (MTs) were shorter when the description of the imagined partner was a 'high' performer compared to a 'low' performer. Interestingly, participants not only adjusted the partner's portion of the task, but they also adjusted their own portion of the task - imagined MTs of the first disc transfers were shorter when imagining performing the task with a high performer than with a low performer. These findings suggest that MI is based on the simulation of one's own response code, and that the adaptation of MI to their partner's movements influences the MI of one's own movements.