Cadaveric elbow allografts. A six-year experience.
ABSTRACT Transplantation of total elbow allografts has been employed as a salvage procedure in an attempt to provide patients with a useful, painless range of motion of the elbow. Patients who are candidates for this procedure include those with disabling elbow joint symptoms who refuse an arthrodesis or are not candidates for conventional total elbow replacement because of excessive bone loss or young age. Allografts must be subjected to rigid internal fixation. Rush rod fixation used early in this series was associated with a high incidence of nonunion. In this series, ten patients followed for one to six years were provided with a functional elbow. However, long-term results are still unknown. Although not recommended for routine use, this operation is viewed as a salvage procedure. The use of allografts in elbow reconstruction does not preclude subsequent reconstruction with another allograft or fusion. In patients with deficient bone stock, the allografts reestablish bone mass to permit an arthrodesis or reconstructive arthroplasty.
Article: Multi-circular flux motor[Show abstract] [Hide abstract]
ABSTRACT: The paper introduces a new type of electrical machines which has significantly high output torque. The toothed-rotor in the conventional electrical machine is replaced by a multi-circular rotor to increase the saliency and to shorten the flux loops consequently the output torque increases. The paper presents the design steps of this new type of electrical machine and also examines its performance. In addition, the paper compares the percentage increase in output torque from the proposed new electric machine to its equivalent conventional motor. Then the paper proceeds to discuss the relation between the switching on angle and the maximum speed, the torque ripples, and the efficiency.Energy Conversion and Management 11/2011; 52(12):3446-3456. · 3.59 Impact Factor
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ABSTRACT: Traumatic sequelae of the elbow are difficult to manage because of bone deformities, changes in joint congruency and bone defects. Total elbow arthroplasty is a therapeutic option when the joint space has disappeared. Nineteen patients underwent semi-constrained Coonrad-Morrey(®) total elbow arthroplasty in 12 cases for post-traumatic elbow arthritis (group 1) and in seven cases for 7 non-union of the distal humerus (group 2). The mean age at surgery was 60years old (56 in group 1 and 67 in group 2). The mean delay between the initial trauma and arthroplasty was 16years (group 1) and 22months (group 2). At a mean follow-up of 5.5years (24-156months) in group 1, the Quick-DASH score was 34 points with outcomes that were considered to be good to excellent in 75% of the cases according to the Mayo Elbow Performance Score (MEPS). A progressive radiolucency was identified on X-ray in 33% of the cases, and moderate wear of the polyethylene insert in 17%. There were 7 complications (58%) requiring revision in 3 cases (25%). At a mean follow-up of 4.6years (24-108months) in group 2, the Quick-DASH score was 39 points with good and excellent results in 86% according to the MEPS. A radiolucency was noted in 28% and moderate wear of the inserts in 14%. There were 2 complications (28%) requiring revision in 1 case (14%). Semi-constrained total elbow arthroplasties provide recovery of functional range of motion with a stable and pain-free elbow for post-traumatic conditions. The age at surgery is a risk factor for complications. The indication for total elbow arthroplasty in patients under 60 should be carefully considered in relation to alternative treatment options. Level IV Retrospective study.Orthopaedics & Traumatology Surgery & Research 12/2013; · 1.17 Impact Factor
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ABSTRACT: To obtain high-pressure gas, air-driven boosters are widely used. The most common booster is called input pressure reduced booster (IPR booster). The IPR booster’s output pressure is set by reducing the input pressure of the driving chambers. In this paper, a new kind of booster, expansion energy used booster (EEU booster), is proposed, which makes use of the expansion power of the compressed air in the driving chambers. Through analysis of the boosters, a mathematical model of the working processes is set up. Using the software MATLAB/Simulink for simulation, the motion characteristics of the piston, the variations of the pressure of the boosting chambers and the driving chambers, the characteristics of the output flow of the boosters were obtained. Moreover, a new energy consumption evaluation criterion of pneumatic system, air power, is briefly introduced. Simulation and experimental results of the boosters were conducted and the output air power and efficiency characteristics of the boosters were obtained. Results show that, first of all, the simulation results have a good consistency with the experimental results. Secondly, when the air source pressure and the output pressure are set at 0.6MPa and 0.8MPa respectively and the terminal pressure of the driving chamber is increased, the output flow of both the IPR and the EEU boosters increase stably. When the terminal pressure exceeds 200L/min, the output flow of the EEU booster remains almost constant. Thirdly, with the same terminal pressure, the air power efficiencies of the two kinds of boosters remain the same. Lastly, if the output pressure is set at 0.8MPa, under the optimum work state of the EEU booster, the output air power of the two kinds of boosters both decline with an increase in the boosting ratio. However, the output air power of the EEU booster is higher than that of the IPR booster by approximately 2.5kW, which is about 1.4–4 times of that of IPR booster. When the boosting ratio is 1.6, the output air power of the EEU becomes 4 times of that of the IPR booster. This research can be referred to in the design of the boosters.Energy Conversion and Management 11/2011; 52(12):3399-3407. · 3.59 Impact Factor