Objective To explore devising and clinical effect of ladder-shaped osteotomy and guide apparatus. Methods From February 2002 to January 2004, with the application of guide apparatus devised,the ladder-shaped osteotomy was designed and completed by bone drill and linear saw. The experiment of ladder-shaped osteotomy was carried out on a fresh bone trunk amputated. Clinically, 3 cases were replanted by shortening humerus by means of laddershapedosteotomy. The lengths of bone shortened were 3 to 7 cm. The bone length of ladder-shaped osteotomy was 2 to 3 cm. Two cases of radius defect was repaired with free fibula. The lengths of bone transplanted were 7 and 11 cm. The bone length of ladder-shaped osteotomy was 1 cm. Results It took 2 to 3 minutes to complete the laddershaped osteotomy on the two ends of bone defect. The ends of ladder-shaped osteotomy was integrated closely. All 5 cases were followedup for 10 to 16 months. All fractures healed during 14 to 20 weeks. Of 3 cases shortening humerus, the function of elbow joint was normal in 1 case, the activity range of elbow joint was 0 to 100° in 1 case,and 0 to 80° in 1 case, respectively. Of 2 cases undergoing fibula transplantation, the function of wrist and elbow joint were normal;the pronation and supination ranges of the forearm was 30° and 40° in one, 50° and 45° in the other. Conclusion With the introduction of guide apparatus, the laddershaped osteotomy by bone drill and linear saw is a recommendable procedure because of many advantages such as simple apparatus, shortcut, laborsaving and precision.
Evidence-based evidence translated into health care services requires three conversion processes, preclinical research-clinical research-implementation research, which might take a very long time. In order to speed up the process of research results translated into daily medical practice and health policy, an effectiveness-implementation hybrid design combining the effectiveness research of clinical and implementation research was emerging. This paper introduced the concept, classification and application of effectiveness-implementation hybrid design, to provide references for researchers in this area.
Based on the analysis of the influence of the valve pivot distance on the performance of mechanical heart valve (MHV), such as the valve opening and closing features, flow field characteristics and the valve assembly properties, value constraints of the valve pivot distance were established, and the reasonable valve was obtained by means of the finite element method. It can be shown that the central flow characteristics of the valve could be enhanced with the increasing of the ratio of pivot distance to valve inner diameter, but the plastic deformation of the ring could be liable to occur in the MHV assembly process. It is proved that the valve of specifications can be designed in similar ratio of pivot distance to valve inner diameter according to the result of the valve performance experiment.
On the basis of fundamental ethical principles and requirements, combining the practice of ethical management and according to the characteristics and requirements of the prospective cohort study of natural populations, this paper probes into the many key points of ethical design, including the use of existing data, the choice of exposures, the protection of special population subjects and the renewal of informed consent, and the selection of prospective cohort study of natural populations, to provide the beneficial reference to maximize the guarantee of the safety and rights and interests of the subjects.
ObjectiveTo observe the effectiveness of lateral arm free perforator flap by personalized design in repairing irregular defects of the hand. MethodsTwelve patients with irregular defects of the hand were repaired with lateral arm free perforator flaps by personalized design between January 2010 and January 2015. There were 7 males and 5 females with a mean age of 35 years (range, 18-52 years). The causes included crush injury in 5 cases, thermal injury in 3 cases, traffic accident injury in 2 cases, and friction injury in 2 cases. The time between injury and admission was 1.0-4.5 hours (mean, 3.1 hours). In 3 patients with skin and soft tissue defect of approximate square, the flap of less than 6 cm in width was designed and was segmented into foliated flaps to repair wound; the bilobed flaps were used in 5 cases of hand penetrating wounds; the bilobed flaps or trifoliate flaps were used in 4 cases of multiple finger skin soft tissue defects. The total area of the defects ranged from 6.0 cm×5.0 cm to 9.0 cm×8.0 cm, and the area of flap ranged from 10.0 cm×3.5 cm to 12.0 cm×6.0 cm. All the wounds at donor site were closed directly. ResultsAll the flaps survived, wounds and incisions at donor sites healed by first intention. The patients were followed up 6-15 months (mean, 10 months). Bulky flaps were observed in 2 cases of female patients, and flap thinning was performed at 3 months after operation. The hand function recovered satisfactorily, and the sensation was S1-S3 at 6 months after operation. According to the functional assessment criteria of upper limb formulated by the Hand Surgery Branch of Chinese Medical Association, the results were excellent in 2 cases, good in 7 cases, fair in 2 cases, and poor in 1 case. The linear scars was observed at the donor site. ConclusionThe lateral arm free perforator flap has constant vessels anatomy, and there are many perforators in the intermuscular septum. The lateral arm free perforator flap by personalized design can repair irregular defects of the hand.
With the encouragement of national policy on drug and medical device innovation, multi-center clinical trials and multi-regional clinical trials are facing an unprecedented opportunity in China. Trials with a multi-center design are far more common at present than before. However, it should be recognized there still exists shortcomings in current multi-center trials. In this paper, we summarize the problems and challenges and provide corresponding resolutions with the aim to reduce heterogeneity between study centers and avoid excessive center effects in treatment. It is urgent to develop design, implementation and reporting guidelines to improve the overall quality of multi-center clinical trials.
ObjectiveTo systematically reviewed the progress of Zelen’s design and its modifications in clinical research and clarified its methodological elements, advantages, and limitations. MethodsA systematic literature search was conducted for Zelen’s design from databases. The data were extracted. ResultsOne hundred and twenty-four trials were included. The dominant disease in this design was mental disorders, followed by osteoarthrosis diseases, cancer, cardiovascular diseases, and others. Regarding types of consent, more than half of the trials used a double-consent (71, 57.26%), and 42 used a single-consent. Eleven trials used a modified Zelen’s design nested within an observational study. This design used a two-stage informed consent. Stage 1, patients were invited to participate in a cohort study; Stage 2, patients randomized in the experimental group were informed of the allocation result and asked whether they would like to follow the treatment. Five trials used the McNulty-Zelen design, which could be applied in cluster randomized controlled trials and overcome the potential bias of the Hawthorne effect. Intention-to-treat analysis was the main population used in Zelen’s design. ConclusionZelen’s design has a broad application in the foreground in clinical trials. It could also be used to adapt to research needs by combining with various observational studies. Zelen’s design offers unique advantages in reducing recruitment difficulty, improving patient compliance, and minimizing bias. Although the randomization of patients without their prior consent raises potential ethical concerns, these can be addressed through methods such as nested observational studies or supplementary informed consent. In real-world applications of Zelen’s design, it is necessary to design a reasonable informed consent strategy and data statistical analysis method according to the research context. Attention must be paid to the impact of sample size, group shifting and selection of dataset on the results, to improve the interpretability and accuracy of the results.
Objective To investigate the value of computer-aided design (CAD) in defining the resection boundary, reconstructing the pelvis and hip in patients with pelvis tumors. Methods Between November 2006 and April 2009, 5 cases of pelvis tumors were treated surgically using CAD technology. There were 3 males and 2 females with an average age of 36.4 years (range, 24-62 years). The cause was osteosarcoma, giant cell tumor of bone, and angiosarcoma in 1 case, respectively,and chondrosarcoma in 2 cases. According to the Enneking system for staging benign and mal ignant musculoskeletal tumors, regions I, I + II, III, IV, and I + IV is in 1 case, respectively. According to the principle of reverse engineering, 5 patients with pelvis tumors were checked with lamellar CT/MRI scanning, whose two-dimensional data were obtained in disease area. The three-dimensional reconstruction of pelvic anatomical model, precise resection boundary of tumor, individual surgical template, individual prosthesis, and surgical simulation were precisely made by computer with CAD software. Based on the proposal of CAD, the bone tumor was resected accurately, and allograft il ium with internal fixation instrument or allogeneic il ium with personal ized prosthetic replacement were used to reconstruct the bone defect after tumor was resected. Results The operation was successfully performed in 5 cases. The average operation time was 7.9 hours, and the average blood loss was 3 125 mL. Hemorrhage and cerebrospinal fluid leakage occurred in 1 case, respectively, and were cured after debridement. Five patients were followed up from 24 to 50 months (mean, 34.5 months). All patients began non-weight bearing walk with double crutches at 4-6 weeks after operation, and began walk at 3-6 months after operation. Local recurrence developed in 2 patients at 18 months after operation, and resection and radiotherapy were performed. According to International Society of Limb Salvage criteria for curative effectiveness of bone tumor l imb salvage, the results were excellent in 2 and good in 3. Conclusion The individual surgical template, individual prosthesis, and surgical simulation by CAD ensure the precision and rel iabil ity of pelvis tumors resection. The CAD technology promotes pelvis tumor resection and the reconstruction of pelvis to individual treatment stage, and good curative effectiveness can be obtained.