Rapid prototyping technology, a kind of novel digital prototyping technology developed in mid-1980s based on a principle of discrete and accumulation, which fabricates a prototype by accurate accumulation of material according to the CAD models or CT data under the control of the computer without any other device. In recent years, it has shown a great application prospect in the field of orthopedics combined with three-dimensional image reconstruction of spiral CT and MRL In this article, review is given on the application development of rapid prototyping technology in orthopedics, such as organ model preparation and surgical planning, customized implant and bone tissue engineering porosity scaffold fabrication.

As an essential element of tissue engineering,the shape,pore size,and porosity of the porous scaffolds have direct influence on the attachment,proliferation,and differentiation of seeding cell as well as their properties.So it is important to be able to prepare an ideal porous scaffold which is able to provide the cells with an excellent micrcenvirenment in order to support their growth and differentiation.In this article,we reviewed some kinds of the preparation technologies of the porous scaffolds for tissue engineering,including fiber bonding,emulsion freeze drying,solvent casting/particulate leaching,high-pressuro processing,gas foaming/particulate leaching,thermally induced phase separation,and electro-spinning,with focus on rapid prototyping.It is our belief that the combination of the basic technologies and the rapid prototyping technology which is able to control the properties of the scaffolds and could be applied for individualized scaffold construction would be the major focus of research in the future.

Implant drug delivery system(IDDS) is helpful to the therapy of infection、tuberculosis and tumor of bone. With the development of tissue engineering, various materials has been used as the carriers for the IDDS. Research of the carrier materials used in implant drug delivery system is reviewed in this article.

Objective To quantitatively evaluate relative contribution of medical history,physical examination and laboratory investigation to diagnoses for medical outpatients.Methods In total,145 medical visitors to the outpatient department of Peking Union Medical College Hospital (PUMCH) during October 10 to 16,2008 were recruited and followed-up for 12 months.Results Nineteen of 145 visitors (13.1%) were lost during the period of follow-up and diagnoses were established for 86 of them (68.3%)finally with medical history and for 20 (15.9%) with physical examination or laboratory investigation,respectively.Confidence index of internists in their correct diagnosis increased to 7.3 with medical history and to 7.9 and 8.7 with physical examination and laboratory investigation in average,respectively.Conclusions Most visitors to internal medicine department could be diagnosed correctly with medical history only.On the basis of physical diagnosis,selection of adequate laboratory investigation for them is critical to improvement of clinical diagnosis.

Next-generation sequencing has boosted the development and application of non-invasive prenatal testing.Non-invasive prenatal screening of fetal aneuploidies (T21/T18/T13) has been widely applied around the world as the well-recognized best screening method because of its high sensitivity, low false-positive rate and false-negative rate.Non-invasive prenatal testing of fetal sex chromosome aneuploidies, common chromosome deletion-duplication syndromes and several monogenic disorders has also become technically feasible.It can be expected that primary challenges in the future would be the issues of clinical services and proper managements.

Objective To evaluate the biocompatibility of porous drug implant scaffolds prepared by 3D printing technique. Methods Porous drug implant scaffolds were fabricated by 3D printing technique, and a series of tests were carried out to validate the biocompatibility, including acute systemic toxicity, hot source test, local irritation reaction, micronucleus test, muscle implant test and so on. Results The porous drug implant scaffolds showed no acute systemic toxicity, no pyrogenetic effect, no local erythema and edema in local irritation re-action, hemolysis rate of 0.29%, no cellular genetoxic. No local tissue denaturation, necrosis and exclusion were found in intramuscular implant test. Conclusion With good biocompatibility, the porous drug implant scaffold fabricated by 3D printing technique can meet the clinical requirement for biomaterial.

Objective To study the oxidative stress state of mice before and after air simulated diving. Methods Forty-eight mice were divided into 6 groups randomly. Every group was exposed to corresponding pressure for 60 minutes, twice a day for consecutive 3 days. Blood was obtained at the corresponding time to observe the changes of maleic dialdehyde, glutathione, glutathione-s-transferase, glutathione peroxidase, superoxide dismutase and catalase. Results Compared with the control, the activity of glutathione-s-transferase, glutathione peroxidase, superoxide dismutase, catalase and the level of glutathione were markedly inhibited and maleic dialdehyde increased in HO group and HA1 group (P

Objective To explore the effect and factors of patellofemoral arthroplasty (PFA) for isolated patellofemoral osteoarthritis.Methods Data of 18 patients (3 males,15 females) with isolated patellofemoral osteoarthritis underwent PFA from March 2006 to December 2014 were retrospectively analyzed.There were 3 males and 15 females with a mean age of 54 years (range,46-74 years).It was strict to grasp the surgical indications according to the clinical symptoms,signs and imaging data preoperatively.11 patients were operated with AVON patellofemoral prosthesis (Stryker Inc.) and the other 7 patients were operated with the Gender Solutions patellofemoral prosthesis (Zimmer Inc.).Active and passive functional rehabilitation exercise was encouraged at the early stage after operation.Visual analogue scale (VAS) was 5.33±0.99 (range,4-7) and hospital for special surgery knee score (HSS) was 53.28±5.71 (range,44-63) before operation.Results The mean duration of follow-up was 63.98 months (range,6-104 months).VAS after operation for 1 and 3 months were 1.17±0.79 (range,0-3) and 0.72±0.67 (range,0-2),and the pain was almost relieved after 9 months.HSS after operation for 1,3,9 months were 70.06±6.33 (range,61-80),86.06±5.12 (range,77-95) and 91.39±4.83 (range,82-97).HSS score of the latest follow-up was 92.06±4.05 (range,84-97),which was improved obviously from the preoperative ones.The excellent and good rate was 100％ (excellent 15 cases,good 3 cases).The satisfactory rate was 94.4％ (17/18).Only one case got slightly knee pain when walking up and down the stairs after 2 years,and the pain was relieved after being administered with NSAIDs and rest.No incision infection,rupture,prosthesis supported bone fracture,prosthesis loosening and other complication was occurred during the follow-up period in the other patients.Conclusion The clinical outcomes of PFA are strictly related to surgical indications,implant design and appropriate surgical technique.Therefore,based on the appropriate PFA implants,strict surgical indications,appropriate patients,excellent operation skills and actively functional rehabilitation exercise,PFA could treat the isolated patellofemoral osteoarthritis effectively.