Upper limb involuntary tremor reduction using cantilever beam TMDs

Tuned mass dampers (TMDs) are proposed as a solution to reduce the involuntary tremor at the upper limb of a patient with postural tremor. The upper limb is modeled as a three-degrees-of-freedom rotating system in the vertical plane, with a flexion-extension motion at the joints. The measured extensor carpi radialis signal of a patient is used to excite the dynamic model. We propose a numerical methodology to optimize the parameters of the TMDs in the frequency domain combined with the response in the time domain. The objective function for the optimization of the dynamic problem is the maximum angular displacement of the wrist joint. The optimal stiffness and damping of the TMDs are obtained by satisfying the minimization of the selected objective function. The considered passive absorber is a cantilever beam–like TMD, whose length, beam cross-sectional diameter, and mass position reflect its stiffness for a chosen additional mass. A parametric study of the TMD is conducted to evaluate the effect of the TMD position along the hand segment, the number of TMDs, and the total mass of TMDs. The sensitivity of the TMD to a decrease of its modal damping ratio is studied to meet the range of stainless steel. TMDs are manufactured using stainless steel beams of the same length (9.1 cm) and cross-sectional diameter (0.79 mm), for which the mass (14.13 g) position is adjusted to match the optimal frequency. Three TMDs holding a mass of 14.13 g each cause 89% reduction in the wrist joint angular displacement.

The proximal fibular free flap - an ideal material for reconstructing distal radius defect after Giant tumor cell resection. A case report

Giant cell tumors (GCT) of the distal end of radius are relatively common tumors, representing approximately 5% of all primary bone tumors. It is the third most common location for GCT following distal femur and proximal tibia. In general, treatment includes thorough tumor excision, reconstruction of the defect, and wrist joint rehabilitation. The proximal fibular free flap is an ideal material for distal radius reconstruction after giant cell tumor excision. We present a case of a 57-year-old female, admitted to the hospital due to painful and limited proper wrist movement. Based on X-ray and Magnetic resonance imaging (MRI) images and histopathology findings, the patient was diagnosed with a stage 3 giant cell tumor of the distal radius. The patient underwent a one-step surgery of tumor excision and distal radius reconstruction by a vascularized proximal fibular free flap. 2 years follow-up post-surgery showed that the patient had no pain of the wrist, improved wrist joint function, no sign of recurrence, and good flap vitality and the knee joint remains normal. In conclusion, the surgery was successful with no further prolonged pain, improvement of the wrist joint function and overall improvement of the patient quality of life.

Preparation and tensile conductivity of carbon nanotube/polyurethane nanofiber conductive films based on the centrifugal spinning method

Flexible conductive thin films have recently become a research area of focus in both academia and industry. In this study, a method of preparing nanofiber conductive films by centrifugal spinning is proposed. Polyurethane (PU) nanofiber films were prepared by centrifugal spinning as the flexible substrate film, and carbon nanotubes (CNTs) were used as the conducting medium, to obtain CNTs/PU nanofiber conductive films with good conductivity and elasticity. The effects of different CNT concentrations on the properties of the nanofiber films were investigated. It was found that the conductivity of the nanofiber conductive films was optimal when an impregnation concentration of 9% CNTs was used in the stretching process. Cyclic tensile resistance tests showed that the nanofiber conductive films have good durability and repeatability. Physical and structural property analysis of the CNT/PU conductive films indicate that the adsorption of the CNTs on the PU surface was successful and the CNTs were evenly dispersed on the surface of the matrix. Moreover, the CNTs improved the thermal stability of the PU membrane. The CNT/PU conductive films were pasted onto a human finger joint, wrist joint, and Adam's apple to test the detection of movement. The results showed that finger bending, wrist bending, and laryngeal prominence movement all caused a change in resistance of the conductive film, with an approximately linear curve. The results indicate that the CNT/PU nanofiber conductive film developed in this study can be used to test the motion of human joints.

Measuring Upper Limb Kinematics of Forehand and Backhand Topspin Drives with IMU Sensors in Wheelchair and Able-Bodied Table Tennis Players

To better understand the biomechanics of para-table tennis players, this study compared the shoulder, elbow, and wrist joint kinematics among able-bodied (AB) and wheelchair players in different classifications. Nineteen participants (AB, n = 9; classification 1 (C1), n = 3; C2, n = 3; C3, n = 4) executed 10 forehand and backhand topspin drives. Shoulder abduction/adduction, elbow flexion/extension, wrist extension/flexion, respective range of motion (ROM), and joint patterns were obtained using inertial measurement unit (IMU) sensors. The results showed clear differences in upper limb kinematics between the able-bodied and wheelchair players, especially in the elbow and wrist. For the para-players, noticeable variations in techniques were also observed among the different disability classes. In conclusion, wheelchair players likely adopted distinct movement strategies compared to AB to compensate for their physical impairments and functional limitations. Hence, traditional table tennis programs targeting skills and techniques for able-bodied players are unsuitable for para-players. Future work can investigate how best to customize training programs and to optimize movement strategies for para-players with varied types and degrees of impairment.

Trapeziectomy for basal thumb osteoarthritis does not increase the risk of developing wrist osteoarthritis in the long term

Background Symptomatic osteoarthritis of the basal joint of the thumb (trapeziometacarpal joint) is a common disabling condition mainly affecting women. It is frequently treated with complete removal of the trapezium with or without soft-tissue interposition. There is limited evidence about whether removal of the trapezium affects stability of the wrist joint and increases the risk of developing wrist osteoarthritis. The aim of this study was to evaluate the long-term prevalence of OA in wrists with previous trapeziectomy compared to wrists with intact trapezium. Methods Patients treated with surgery for trapeziometacarpal osteoarthritis at one orthopedic department were invited 10–29 (mean 17) years postoperatively for bilateral radiographic examination. We included radiographs from 114 hands with trapeziectomy and 46 hands with intact trapezium; 38 patients had unilateral trapeziectomy and intact contralateral trapezium. The radiographs were blinded so that the intact trapezium or the trapezial space after trapeziectomy was not visible. The radiographs were then evaluated for radiocarpal/midcarpal osteoarthritis independently by two assessors using three different osteoarthritis grading systems, including the Kellgren–Lawrence classification. The patients rated their satisfaction with the function of each of their hands on a visual analog scale (VAS) from 0 to 100 (higher score better). Results The prevalence of osteoarthritis ranged from 20 to 26%, mostly mild (Kellgren–Lawrence grade 1). The prevalence of osteoarthritis did not differ between wrists with previous trapeziectomy and those with intact trapezium, both in the whole cohort and in the subgroup of patients with unilateral trapeziectomy and intact contralateral trapezium. There was no significant difference in hand function VAS scores between hands with previous trapeziectomy and hands with intact trapezium in the whole cohort or in the subgroup. Conclusions Removal of the trapezium as treatment for basal thumb osteoarthritis does not increase the risk of developing wrist osteoarthritis in the long term.

Diagnosis and treatment of hygroma of the wrist joint in the practice of an outpatient surgeon

Introduction. Synovial cyst or hygroma is a common disease that occurs in both children and adults, but it is most often observed in people 20–45 years old. More than 60% of patients who go to the polyclinic with complaints about the presence of tumor-like formations have hygroma.Goal. Analysis of the results of treatment of synovial cysts of the hand and wrist joint according to our own observations and literature data.Material and methods. We observed 54 patients suffering from hygroma of the hand and wrist joint, who were treated in polyclinic No. 2 and MEDEL multidisciplinary clinic in Kazan from 2005 to 2020. The treatment of hygrom was carried out using conservative (puncture) and surgical methods. Results. Our experience showed that after a single puncture of the hygroma with the evacuation of its contents (10 patients), relapse developed in all cases. After repeated puncture of the hygroma in 10 patients with evacuation of the contents and subsequent administration of 0.5 ml of betaspan solution, 6 of them did not relapse within 5–6 months, but 4 patients had a relapse in the nearest period (1–2 months). Of the 23 patients who underwent surgery to remove the hygroma, 15 of them had no relapses. In 8 patients in the postoperative period, recurrent hygroma occurred, which could be explained by the ineffectiveness of eliminating the communication zone between the hygroma and the joint.Conclusions. For the successful treatment of this disease, it is important to understand that for the occurrence and development of hygroma, its communication with the joint cavity or tendon vagina is of great importance. In the absence of a message, the successful use of puncture methods of treatment is possible. In the presence of such a message and its detection during preoperative examination, surgical treatment should be planned with mandatory ligation of the leg of the hygroma.

Surgical Treatment of Wrist Joint Dysfunction in Rheumatoid Arthritis: A Report of Two Cases

In rheumatoid arthritis (RA), it is important to actively treat wrist dysfunction to improve patient outcomes. Herein, we report two cases of wrist dysfunction in RA patients who required partial wrist fusion soon after drug initiation. [Case 1] A 38-year-old woman was referred to our hospital because of left wrist joint pain. At the time of examination, swelling and tenderness of the left wrist joint were observed. After 6 months of medication, no improvement in symptoms was noted; therefore, partial wrist fusion was performed. [Case 2] A 38-year-old woman was referred to our hospital because of right wrist joint pain. A plain X-ray image showed fusion of the carpal bones. Due to previous failure of drug treatment, the patient opted for arthrodesis. The postoperative course was good in both cases, and the pain improved. In these cases of monoarthritic RA, synovitis and bone destruction were observed, but blood tests showed no features of active disease, and drug treatment was ineffective. In such cases, early surgical treatment should be considered, rather than continuing conservative treatment, to ensure the best outcomes.

Modified osteotomy for treatment of forearm deformities (Masada IIb) in hereditary multiple osteochondromas: a retrospective review

Purpose Approximately 30% of patients with hereditary multiple osteochondromas (HMO) have forearm deformity and dysfunction. The aim of this retrospective study was to review our experience with the surgical treatment of children with HMO and Masada IIb forearm deformities. Methods Data of eight children treated for HMO Masada IIb forearm deformity at our hospital between 2015 and 2019 were collected from the hospital records and retrospectively reviewed. All patients underwent ulnar lengthening by distraction osteogenesis using either the Orthofix or Ilizarov external fixator. Range of movements at the elbow and wrist joints, and forearm supination/pronation, before and after the operation were recorded. Radiographs were evaluated by the Fogel method, and wrist joint function by the Krimmer method. Results Follow-up radiographs showed significant improvement in relative ulnar shortening after treatment (pre-operative 9.23 ± 5.21 mm; post-operative 0.33 ± 4.13 mm). Changes in radial articular angle (pre-operative 33.55° ± 3.88° to 32.78° ± 6.57°) and carpal slip (pre-operative 45.00% ± 19.09%; post-operative 43.13% ± 16.68%) were not significant. Elbow flexion and extension, wrist flexion and extension, ulnar and radial deviation at wrist, and forearm rotation were significantly improved after surgery. Wrist function was graded as excellent in seven patients and as good in one patient. One patient treated with the Ilizarov external fixator had poor radial head reduction. Conclusion Ulnar lengthening with distraction osteogenesis is an effective treatment for HMO Masada IIb deformities. The optimum site for ulnar osteotomy appears to be at the proximal one-third to one-fourth of the ulna.