Joint Deformity Research Articles

Nrf2 participates in progression of osteoarthritis through modulating redox balance

Osteoarthritis (OA) is one of the most common degenerative joint diseases associated with aging, obesity and joint trauma, and is always associated with pain, joint deformity and dysfunction. Recent studies have shown that OA is closely related to oxidative stress, which serves as a major cause of chronic inflammation in cartilage, leading to irreversible structural changes in the joint. As a transcription factor, nuclear factor erythroid 2-related factor 2 (Nrf2) plays an important role in the antioxidant system, which regulates the expression of cytoprotective genes to facilitate the elimination of reactive oxygen species (ROS). In this review, we have summarized the dramatic function of oxidative stress in OA pathology, established a complex regulatory network of Nrf2 in OA progression, and aimed to provide new insights into the treatment of OA.

Model test investigation on the longitudinal mechanical property of shield tunnels considering internal structure

Reasonable evaluation of longitudinal mechanical property of shield tunnel is critical to the design and maintenance of tunnel structures. Traditionally, the internal structure has not been involved in the existing studies on the longitudinal mechanical properties of shield tunnels, of which the effect on the longitudinal mechanical properties of shield tunnels remains unknown. In this study, a series of physical similar model tests were conducted on homogeneous model (HM), non-homogeneous model (NHM) and non-homogeneous model with internal structure (NHMI), the effect of internal structure and longitudinal force on the longitudinal mechanical properties of road-metro shield tunnels were investigated. The longitudinal strain, displacement, curvature, and circumferential joint deformation of the tunnels were analyzed in depth. The experimental results show that the internal structure can reduce the longitudinal deformation of shield tunnels greatly, and the maximum displacement of tunnels with internal structure can be reduced by 70.58 %, the curvature radius can be increased by 1.73 to 2.36 times, the dislocation of the circumferential joint can be reduced by up to 70.4 %, and the opening of the circumferential joint can be reduced by up to 67.37 %. The longitudinal bending stiffness efficiency of tunnels ranges from 0.66 to 0.86 after taking into account the effect of internal structures. Increasing the longitudinal force from 0 MPa to 0.3 MPa significantly improves the longitudinal bending stiffness efficiency of tunnels, after which increasing the longitudinal force has no significant effect on the longitudinal mechanical properties of the tunnel.

ANATOMICAL AND FUNCTIONAL PREREQUISITES FOR THE DEVELOPMENT OF ENDOPROSTHESIS INSTABILITY AFTER MONOCANDYLAR KNEE ARTHROPLASTY

Monocondylar knee arthroplasty allows to restore normal kinematics and function of the knee joint in the case of osteoarthritis limited to the medial or lateral part of the joint. Objective. To identify the patterns and features of secondary anatomical and functional changes in the knee joint after monocandylar arthroplasty depending on the patientʼs gender, weight, etiology of gonarthrosis, the magnitude of the primary joint deformity and bone tissue condition. Methods. The results of the examination of 71 patients (age 37–83 years, follow-up period 3–10 years) were analyzed. In 20 (28.2 %) patients, problems with the arthroplasty joint occurred. joint: increased frontal deformity angle — 8 (40 %), decreased joint mobility — 12 (60 %), pain in the implantation area — 10 (50 %). Results. Preoperative factors that may affect the outcome of monocandylar knee arthroplasty were identified. The main one is reduced bone density, especially localized osteoporosis. In the presence of osteoporotic areas in the area of arthroplasty, the risk of endoprosthesisinstability can reach 100 %. The second important factor is frontal deformities of the knee joint of more than 10°. Other factors, such as obesity, meniscal and crossed ligament injuries, fractures of the femoral and tibial condyles, also affect the development of complications, especially with a simultaneousdecrease in bone mineral density and/or significant frontal deformity of the knee joint. Conclusions. Monocondylar knee arthroplasty is a reliable, costeffective, low-traumatic method of treating gonarthrosis, but subject to clear indications for its implementation. In the long term, patients with osteoporosis, meniscal and ligamentous injuries, fractures of the condyles, and frontal deformities of more than 10° may develop signs of endoprosthesis instability.

BH05 Successful treatment of acrodermatitis continua of Hallopeau with methotrexate

Abstract A 39-year-old woman was referred with a 3-month history of brittle nails, painful fingertips and psoriasiform plaques affecting her torso and limbs. She had a past medical history of macrocytic anaemia secondary to dietary B12 and folate deficiencies, which required inpatient transfusions. She had no previous dermatological concerns, and there was no history of infection or trauma to the affected sites. On examination of her hands and feet, there was evidence of nailbed pustulation, subungual hyperkeratosis, onychodystrophy, anonychia of multiple nails and dactylitis, consistent with acrodermatitis continua of Hallopeau (ACH) with associated psoriasis. At diagnosis, the patient’s Dermatology Life Quality Index (DLQI) was 16, she had a Psoriasis Area and Severity Index (PASI) score of 18 and a Psoriasis Epidemiology Screening Tool (PEST) score of 4. Nail fungal culture was negative. Plain radiographs of the hands and feet demonstrated a flexion deformity of the left fifth finger distal interphalangeal joint, with otherwise normal bone texture, alignment and joint spaces. The patient was initially treated with potent topical corticosteroids and vitamin D analogues, with little improvement. The patient was commenced on 15 mg subcutaneous methotrexate (MTX), with close monitoring of serum and red cell folate given her background of folate deficiency, which was being actively replaced. Within 3 months of starting MTX monotherapy, the patient’s hands had dramatically improved with skin and fingernail changes largely resolved, and an improvement in manual dexterity (DLQI 11, PASI 3, PEST 5). MTX was increased to 20 mg once weekly and the patient was also started on sulfasalazine 500 mg twice daily by her rheumatologist for psoriatic arthritis. ACH is a chronic pustular eruption initially affecting distal phalanges with gradual proximal progression and the potential development of generalized pustular psoriasis. ACH is considered a variant of palmoplantar pustulosis, commonly affecting adult females with localized trauma and infection as possible triggers. Given the rarity of ACH, the evidence base for therapy is limited to case reports and series, with no standardized treatment guidelines. Topical therapies include corticosteroids, calcineurin inhibitors and vitamin D analogues. Local phototherapy and systemic therapy with acitretin, MTX and ciclosporin have been described, with wide-ranging results. In severe cases such as this, patients typically receive biologic therapy, with variable responses reported with tumour necrosis factor-α inhibitors, anti-interleukin (IL)-6 therapy, and anti-IL-12/IL-23 and anti-IL-17 therapy. We present a rare case of severe ACH and psoriasis, treated with MTX monotherapy, which was not only clinically effective but also cost-effective.

Seismic mitigation performance of shape memory alloy flexible circumferential joint in shield tunnel

AbstractThe circumferential joint of a shield tunnel is prone to damage under strong earthquakes, affecting the safety of the tunnel. This paper adopts an innovative shape memory alloy (SMA) flexible circumferential joint for longitudinal seismic mitigation of the tunnel. The SMA joint is composed of SMA ring springs and ordinary bolts. The SMA joint design is performed for a shield tunnel, and a simplified model of the SMA joint is proposed. Based on the generalised response displacement method, the longitudinal seismic mitigation analysis of the tunnel is conducted, the arrangement of SMA joints is discussed, and the seismic mitigation performance is evaluated. Results show that the SMA joint design method can efficiently complete the joint design, and the SMA joint model can accurately reflect the joint performance. SMA joints can reduce the stiffness of tunnel joints and have a good energy dissipation effect, which is suitable for shield tunnel seismic mitigation. An appropriate SMA joint arrangement can concentrate the tunnel joint deformation and effectively reduce the opening width between the tunnel segment rings. It can also dissipate energy and reduce the internal force of the tunnel joint, thus enhancing the seismic safety of the tunnel.

On vibrations of functionally graded double wishbone structural systems

In the framework of dynamic finite element methodology, this articleinvestigates the free and forced vibration behaviors of functionally graded double wishbone structural systems considering the deformability of links and joints. Due to the advantages of the functionally graded materials (FGMs), the double wishbone control arms are modeled as a plane functionally graded frame based on the Timoshenko beam theory (TBT). The power law is adopted to model the through-thickness material gradation. Based on the power gradation law, analytical expressions for the equivalent material stiffnesses and the equivalent inertia are derived. On the other hand, joint deformability is modeled using flexible translational and rotational springs. The dynamic equations of motion are derived based on the Hamiltonian principle. Based on the isoparametric Timoshenko plane frame element, a displacement-based dynamic finite element model is developed. The accuracy of the developed numerical procedure is verified for both free and forced vibration behaviors and good agreement is obtained. Numerical results are obtained and discussed. The results show the significant effects of the FGM distributions on the free and forced vibration behaviors. The developed procedure and the obtained results are supportive of the design and manufacturing processes of such structural systems.

GANZ HEAD REDUCTION OSTEOTOMY FOR THE TREATMENT OF FEMORAL HEAD DEFORMITIES: RADIOLOGICAL AND FUNCTIONAL OUTCOMES

Ganz's studies made it possible to address joint deformities on both femoral and acetabular side brought by the Legg-Calvè-Perthes disease (LCPD). Femoral head reduction osteotomy (FHRO) was developed to improve joint congruency along with periacetabular osteotomy (PAO). The purpose of this study is to show the clinical and morphologic outcomes of the technique, and an implemented planning approach.From 2015 to 2023, 13 FHROs were performed on 11 patients for LCPD, in two centers. 11 of 13 hips had an associated PAO. A specific CT and MRI-based protocol for virtual simulation of the corrections was developed. Outcomes were assessed with radiographic parameters (sphericity index, extrusion index, integrity of the Shenton's line, LCE angle, Tonnis angle, CCD angle) and clinical parameters (ROM, VAS, Merle d'Aubigné-Postel score, modified-HHS, EQ5D-5L). Early and late complications were reported.The mean follow-up was 40 months. The mean age at surgery was 11,4 years. No major complications were recorded. One patient required a total hip arthroplasty. Femoral Head Sphericity increased from 45% to 70% (p < 0,001); LCE angle from 18° to 42,8° (p < 0,001); extrusion Index from 36,6 to 8 (p < 0,001); Tonnis Angle from 14,4° to 6,2° (p = 0.1); CCD Angle from 131,7 to 136,5° (p < 0,023). The VAS score improved from 3,25 to 0,75,(p = 0.06); Merle d'Aubigné-Postel score from 14.75 to 16 (p = 0,1); Modified-HHS from 65,6 to 89,05 (p = 0,02). The EQ 5D 5L showed significant improvements. ROM increased especially in abduction and extra-rotation.FHRO associated with periacetabular procedures is a safe technique that showed improved functional, clinical and morphologic outcomes in LCPD. The newly introduced simulation and planning algorithm may help to further refine the technique.

Frequency of Microorganisms in Septic Arthritis in Children Under the Age of 10 Years

Background: Septic arthritis is an infrequent disease although very important due to the possibility of disastrous outcomes if treatment is not adequately established. Adequate information concerning the epidemiology of septic arthritis is still lacking. Objective: To find determine the frequency of various microorganisms in septic arthritis in children under age of 10 year. Materials and Methods: This Cross-Sectional Study was conducted in the Department of Orthopedics and Trauma, Medical Teaching Institute Lady Reading Hospital Peshawar Pakistan on from September 2022 to March 2023 on 171 consecutive patients. Non Probability Consecutive Sampling Technique was used in the study. Sample size was calculated using WHO sample size formula, using the proportion, anticipated frequency of E. coli, p=8%3, Margin of error=7.5%, Confidence Level=95%. Patient age 1 month to 10 years of both genders presenting with septic arthritis as per operational definition were included in the study while Patients with congenital joint deformity, Immunocompromised patients, Patients with rheumatologic joint disease and Patients with traumatic joint injury were excluded from the study. Septic arthritis was confirmed with clinical fever, pain and tenderness in the joint and ultrasound showing collection and debris in the joint cavity. Synovial fluid was aspirated for C/S. Pattern of microorganisms in the growth in the culture was noted. Results: Mean age of the patients was 6.68±1.239 years. Out of 177 patients, 96 (%) were male. Large joint arthritis was more common (63.8%). Staph aureus was the most common microorganism isolated in 79 patients (44.6%) while E coli was least commonly isolated (28 patients, 15.8%). Conclusion: S. aureus is still the most common pathogen in acute joint infections in our environment in children under the age of 10 years.

Clinical Characteristics and Factors associated with Bone Erosion in Gout Patients with Tophi

Background: A large number of urate crystals are deposited in the joint cavity for a long time, causing bone erosion and gradually forming joint skeletal muscle necrosis and joint deformity.

Autophagy and apoptosis: regulatory factors of chondrocyte phenotype transition in osteoarthritis.

Osteoarthritis (OA) is the main pathogenic factor in diseases that cause joint deformities. As the main manifestation of the progress of OA, cartilage degradation has been closely associated with the degeneration of chondrocytes, which is induced by inflammatory factors and other trauma factors. Autophagy and apoptosis are the main mechanisms for cells to maintain homeostasis and play crucial roles in OA. Under the influence of external environmental factors (such as aging and injury), the metabolism of cells can be altered, which may affect the extent of autophagy and apoptosis. With the progression of OA, these changes can alter the cell phenotypes, and the cells of different phenotypes display distinct differences in morphology and function. In this review, we have summarized the alteration in cell metabolism, autophagy, and the extent of apoptosis during OA progression and its effects on the cell phenotypes to provide new ideas for further research on the mechanisms of phenotypic transition and therapeutic strategies so as to reverse the cell phenotypes.

Role of genetic variation in Toll like receptor-5 with rheumatoid arthritis pathogenicity in Iraqi patient

Background: Rheumatoid Arthritis (RA) is a persistent inflammatory condition characterized by the immune system’s improper attack of bodily tissues. Rheumatoid arthritis is a chronic autoimmune disorder that impacts the synovial membrane of joints, leading to an inflammatory response characterized by painful swelling. Over time, this condition can progress to the erosion of bone tissue and the development of joint deformities. Aim: characterized the primary objective of the present study was to evaluate the impact of certain variations in the TLR5 gene (namely, rs2072493 and rs45508499) on the severity of Rheumatoid Arthritis among patients from Iraq. Materials and methods: Approximately similar samples from apparently healthy individuals are enrolled as control. The patients attended from April to June 2022 at the Baghdad teaching hospital / medical city /Baghdad / Iraq. It was based on a clinical examination . The single nucleotide polymorphisms (rs2072493 T/A, C, and rs45508499A/G) are examined using the Tetra ARAMS technique. All (SNPs) from the control person are analyzed in the Chi-square test. Results: The analysis revealed a significant association between the rs45508499 polymorphism and the trait of interest. However, no significant association was observed for the rs2072493 polymorphism. Conclusion: The current investigation showed that the presence of TLR5 polymorphism at rs4550899 was associated with RA but rs2072493 was not associated with any effect on the susceptibility to Rheumatoid arthritis .

Сравнительный анализ репозиционных возможностей ортопедического гексапода Орто-СУВ и его минимизированной («педиатрической») версии (экспериментальное исследование)

Introduction Currently, orthopedic hexapods have been effectively used for long bone, foot and large joint deformity correction in both adults and children. Previous studies demonstrated the superiority of the reduction capabilities of the orthopedic hexapod Ortho-SUV Frame (OSF) in comparison with other designs of external fixation devices. However, the reduction capabilities of the minimized version of this hexapod (minimized Ortho-SUV Frame, OSFm) have not been studied yet. Purpose To identify the reduction capabilities of OSFm compared to OSF. Materials and methods The bench test was performed using plastic models of the tibia osteotomized at the middle third of the shaft. One-ring modules were used to fix each of the bone fragments. In the first series of the experiment, the reduction capabilities of OSFm with a standard strut size and in the second series OSF with a short strut size were studied. In each series of experiments, three groups were studied depending on the method of fixing the struts to the rings: directly to the ring, using straight plates, and using Z-shaped plates. Reduction capabilities were assessed by the maximum displacement of the distal bone fragment relative to the proximal one in distraction, translation, angulation, and rotation. Results The magnitude of the maximum distraction of OSF and OSFm with fixation of the struts directly to the rings and with the use of straight plates is the same (p > 0.05). With Z-plates, OSFm outperforms OSF by 27.3 %. OSFm surpasses OSF by 2.8-29.3 % in terms of the planar-parallel movement. OSFm surpasses OSF by 29.6-55.4% in terms of angular movement capabilities. The study of rotational movement found that OSFm exceeds the capabilities of OSF by 20.3-41.3%. Conclusion The findings obtained indicate that OSFm, in comparison with OSF, has better deformity correction capabilities.

Time-dependent virtual crack model of rock with application to slope stability

Time-dependent deformation of rock involves the continuous to discontinuous deformation of joints, cracks, holes, and other defects under long-term stress conditions. Thus, it is of great significance to investigate the correlation between internal crack propagation in rock and external time-dependent damage and failure of rock to better understand the long-term stability of engineering rock mass. Here, we put forward a time-dependent virtual crack model to achieve the entire continuous-discontinuous time-dependent deformation progress of rock from the microscopic to the macroscopic scale. Simulated stress-strain curves for granite, including the mode of failure (axial splitting and Brazilian splitting), agree well with experimental data. We also used the virtual crack model to study the stability of one of the slopes of the Xiaowan Hydropower Station (China). The simulation results indicate that the weakly disturbed zone is the potential sliding surface, and that the deformation of the slope is similar to in-situ measurements. In the model, the vertical displacement decreased by 500 mm in 180 days and the axial strain rate decreased from 25 mm/d to zero, suggested that the slope is currently stable.

Botulinum toxin type A in treatment of chronic migraine, spasticity and bruxism

Introduction: Nowadays, botulinum toxin has found use in many disease entities such as chronic migraine, spasticity, bruxism and many others. Among serotypes A-E, type A is mainly used in treatment. For the therapeutic effect to be maintained, injections need to be repeated most often after 12 weeks. More frequent injections of the toxin may result in the production of neutralizing antibodies. Aim of the study: The aim was to collect and analyze publications of application of botulinum toxin type A (BT-A) in the treatment of chronic migraine, spasticity and bruxism. Methods and materials: We reviewed the literature available in the PubMed database using the key words: “botulinum toxin”; “migraine”; “spasticity”; “bruxism”. Results: The use of botulinum toxin type A in patients with chronic migraine reduces the frequency of pain episodes and alleviates the symptoms. BT-A therapy reduces increased muscle tension, resulting in improved function of the upper or lower limb, facilitating the rehabilitation process, reducing pain associated with spasticity and protecting against the development of muscle contractures and secondary joint deformities. BT-A treatment of patients with bruxism reduces the level of pain and the maximum generated bite force, resulting in an improved quality of life for patients. Conclusion: Intramuscular administration of botulinum toxin is a safe, effective and minimally invasive method of treating chronic migraine, spasticity and bruxism. The botulinum toxin type A is the most studied serotype used for therapeutic purposes. Future research on botulinum toxin will certainly allow wider use.

The knee joint deformities in rheumatoid arthritis patients

Knee joints injury in rheumatoid arthritis patients appear in 70 % cases. This is the most common cause of loss of work capacity, the ability to self-care. Patients become severely disabled, in that the disease is accompanied by deformations with the development of discordant positions of the lower limbs, which lead to a partial or complete loss of the function of support and walking, so this problem needs to be studied. Objective. To make an analysis of orthopedic treatment of secondary arthrosis of knee joints in RA patients, complicated by deformities depending on the age and gender of the patient, stage, duration of the disease and activity of the inflammatory process. Methods. In this work we have analyzed the orthopedic treatment of 66 RA patients with secondary arthrosis with axial deformities, who underwent 75 total endoprosthetics between 2013 and 2020. Anamnestic data, clinical, biomechanical and statistical research methods were used. The obtained data were evaluated using the scale of Joseph J., Kaufman E. E. Results. The analysis of the results of knee joint replacement was followed in the period from 6 months to 5 years. The results were carried out according to the 100-point scale Joseph J., Kaufman E. E. (1990). Thus, the analysis of the results of total knee arthroplasty in patients with RA according to the scale of Joseph J., Kaufman E. E. showed that good results were obtained in 46 (79.31 %) patients, satisfactory results in 11 (18.97 %) and unsatisfactory results obtained in 1 (1.72 %) patients. The reliable relationship of the level of joint deformation with the level of disease activity and with the scale of Joseph J., Kaufman E. E. was researched. Other indicators are not reliably correlated with the level of joint deformation. As a result of pairwise comparisons of groups with each other using the Duncan test, a significant increase in the degree of joint deformation was found in the group with activity 3 compared to the group with activity 1. The use of basic or complex therapy does not reliably affect the degree of joint deformation. Conclusions. Total knee joint replacement need patients with II stage of the 2nd phase of the disease and higher. In our opinion, this is the most optimal time for surgical treatment, which allows patients with RA to fully use the possibilities of an implanted endoprosthesis.

The Role of CCL3 in the Pathogenesis of Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is a chronic autoimmune disease of unexplained causes. Its pathological features includesynovial tissue hyperplasia, inflammatory cellinfiltration in joint cavity fluid, cartilage bone destruction, and joint deformation. C-C motif chemokine ligand 3 (CCL3) belongs to inflammatory cell chemokine. It is highly expressed in inflammatory immune cells. Increasingly,studies have shown that CCL3 can promote the migration of inflammatory factors to synovial tissue, the destruction of bone and joint, angiogenesis, and participate in the pathogenesis of RA. Thesesymptoms indicate that the expression of CCL3 is highly correlated with RA disease. Therefore, this paper reviews the possible mechanism of CCL3 in the pathogenesis of RA, which may provide some new insights for the diagnosis and treatment of RA.

Method of calculating the influence of the suppression system on the autonomy of an armored combat vehicle

A method of calculating the effect of vibrations of the sprung body and the operation of the suspension system of an armored combat vehicle on its autonomy has been developed. One of the main indicators of autonomy is the power reserve, which depends on the specific fuel consumption. In the process of moving over bumps, a significant part of the power plant's energy, and accordingly fuel, is spent on the occurrence of vibrations of the sprung body of the machine and its unsprung masses. Then the energy of these vibrations is converted into heat in the damping devices of the chassis. In difficult road conditions, on real tracks, these losses average 10...15% of power plant power. In resonant modes, when moving along a harmonic profile of irregularities, they can reach 30%. Calculation and reduction of these costs will increase the autonomy of the armored combat vehicle.
 The methodology is based on the calculation of the energy balance of the longitudinal, angular and vertical vibrations of the sprung body of the machine and the vibrations of its unsprung masses, the deformation energies of the elastic elements of the suspension, the rubber hinges of the guide devices and tires, as well as the energies absorbed by the suspension damping devices, its rubber hinges and tires. Depending on this balance, there is either an increase in the load on the power plant and, accordingly, an increase in fuel consumption, or it decreases and the energy of the suspension system becomes the driving force. To calculate the oscillations of the sprung body and components of the energy balance, it is necessary to use a mathematical model of the movement of an armored combat vehicle over bumps. All the necessary parameters of the machine, a deterministic road profile of bumps and a high-speed driving mode are set. Amplitudes and velocities of longitudinal angular and vertical oscillations of the sprung body and oscillations of unsprung masses are calculated from these input data. For each suspension, its kinematics, twisting angles of torsions, forces in damping devices and the amount of movement of their working bodies and deformation of rubber joints and tires are calculated. Next, the magnitude and sign of the change in the total energy of the sprung body and the sprung system at each moment of time is determined. Based on the additional energy calculated using the efficiency coefficients of the engine and transmission, the additional power supplied by the power plant and, accordingly, additional fuel consumption are determined.
 Thus, it is possible to evaluate and compare with each other the reduction in the range of the armored combat vehicle, which is caused by the fluctuations of the sprung body and the operation of the suspension system, depending on the type and characteristics of the suspension, when driving in specific road conditions, at the given speed modes. With the help of the developed methodology, it is possible to carry out structural and parametric optimization of the suspension kinematics and the characteristics of its elastic elements and damping devices, in order to reduce fuel consumption and increase the autonomy of the armored combat vehicle. This technique will be useful in assessing the expediency of using the energy recovery system of the suspension system, depending on the purpose and conditions of operation of combat armored vehicles.

Clinical Presentation of Connective Tissue Disease Patients with and without Interstitial Lung Disease: A Retrospective Study

Background: Connective tissue diseases (CTDs) are responsible for about 20% of interstitial lung disease (ILD) cases, but their diagnosis in a pulmonary unit (PU) is not always straightforward due to a heterogeneous clinical picture. Objectives: The aim of this study was to evaluate the clinical presentation of rheumatoid arthritis (RA) and CTD-ILD cases diagnosed in PU, compared to RA and CTD patients diagnosed in a rheumatologic unit (RU). Methods: Patients with RA, systemic sclerosis (SSc), primary Sjӧgren’s syndrome (pSS), and idiopathic inflammatory myopathy were retrospectively enrolled from an RU and a PU designated to manage ILD during a period from January 2017 to October 2022. The classification of CTD-PU was carried out in a multidisciplinary setting, including the same rheumatologists that diagnosed CTD in the RU. Results: ILD-CTD-PU patients were prevalently male and older. Progression from undifferentiated CTD to a specific condition was more common in ILD-CTD-PU, and those patients generally obtained a lower score on specific classification criteria. RA-PU patients resembled polymyalgia rheumatica in 47.6% of cases, also showing a greater proportion of typical joint deformities (p = 0.02). SSc-PU patients showed a usual interstitial pneumonia pattern in 76% of cases and, compared with SSc-RU, were more commonly seronegative (p = 0.03) and generally lacked fingertip lesions (p = 0.02). The majority of the diagnoses of pSS-PU were in patients with previously diagnosed ILD, in which seropositivity and sicca syndrome developed during follow-up. Conclusions: CTD-ILD patients diagnosed in the PU show severe lung involvement and a nuanced autoimmune clinical picture.

Cutting Process Consideration in Dynamic Models of Machine Tool Spindle Units

Reducing the deviation effect from the specified machining conditions on the quality of the process in real time is the desired result of the intelligent spindle control system. To implement such a control system, a dynamic interaction model of the technological machining system with the cutting process was developed. The transfer matrix method of a multibody system was used in the development of the dynamic model. The physical closure condition of the technological machining system for using the transient matrix method is implemented in the developed model by introducing into this model an additional elastic coupling of the contact between the tool and the machined workpiece. The model is presented as a dynamic model of the elastic system “spindle unit–workpiece/tool–cutting process–tool/workpiece”. To develop the dynamic model, the system decomposition was performed with an analytical description of the joint deformation conditions of the subsystems and the use of the transient matrix method to calculate the harmonic influence coefficients of these subsystems. The proposed approach is used to calculate the native vibration frequencies of the spindle with the workpiece fixed in the chuck and supported with the tool. The calculation results correspond to the experimental ones and quite accurately represent their trends for different contact interaction conditions.

117. Comparative Analysis of Two Hemiarthroplasty Techniques for Symptomatic Distal Radial Ulnar Joint

PURPOSE: Young patients are not impervious to distal radioulnar joint (DRUJ) instability, deformities, and pain. The purpose of this study was to compare and assess the superiority of two techniques of hemiarthroplasty for the treatment of symptomatic DRUJ in a young cohort. METHODS: Thirty-four hemiarthroplasties were performed between 2010 and 2020 by three surgeons at one tertiary medical center. Patients were identified retrospectively and stratified into two groups by implant type: partial ulnar head (A), and Pyrocarbon MCP (B) (off label) (Image 1). Demographics and outcomes were extracted from the electronic medical record. RESULTS: Between the two groups, objective measures of wrist range of motion, grip strength, and pain showed similar findings with improvement across all categories. Statistically significant findings were observed with respect to reduction in pain in both groups as well as improvement in wrist flexion in the pyrocarbon group. Post-operative complications warranting surgical intervention occurred in 10 patients. Of these ten were 2 in the ulnar head implant group; pain and reduced range of motion necessitated one revision to an Aptis implant and one revision to a pyrocarbon implant. In the Pyrocarbon group, 8 surgical interventions were required: 3 pinning in supination for reduced range of motion, 1 exchange with a smaller size implant due to pain, 1 addition of meniscal allografting for pain, and three conversions to Aptis implants for pain and instability. CONCLUSIONS: Painful DRUJs in young patients warrant a surgical intervention which preserves stability and provides longevity with possibility for revision during their lifetime. Hemiarthroplasty allows for preservation of stability, seen in 33/34 patients in this study, with improved symptom management which was seen in 29/34 patients. This study found equal efficacy of the standard ulnar head implant to that of the off-label use of the MCP Pyrocarbon implant. However, the osteointegration of the partial ulnar head implant means future revision would have increased risk of complication. As well, the metallic head of the partial ulnar head implant is known to cause osteolysis of the radial fossa making it less ideal for young patients with future decades of implant wear. Due to these limitations and the similar efficacy, we recommend the use of this prothesis in young patients with symptomatic DRUJ.