The rotation center of traditional hip disarticulation prosthesis is often placed in the front and lower part of the socket, which is asymmetric with the rotation center of the healthy hip joint, resulting in poor symmetry between the prosthesis movement and the healthy lower limb movement. Besides, most of the prosthesis are passive joints, which need to rely on the amputee’s compensatory hip lifting movement to realize the prosthesis movement, and the same walking movement needs to consume 2–3 times of energy compared with normal people. This paper presents a dynamic hip disarticulation prosthesis (HDPs) based on remote center of mechanism (RCM). Using the double parallelogram design method, taking the minimum size of the mechanism as the objective, the genetic algorithm was used to optimize the size, and the rotation center of the prosthesis was symmetrical with the rotation center of the healthy lower limb. By analyzing the relationship between the torque and angle of hip joint in the process of human walking, the control system mirrored the motion parameters of the lower on the healthy side, and used the parallel drive system to provide assistance for the prosthesis. Based on the established virtual prototype simulation platform of solid works and Adams, the motion simulation of hip disarticulation prosthesis was carried out and the change curve was obtained. Through quantitative comparison with healthy lower limb and traditional prosthesis, the scientificity of the design scheme was analyzed. The results show that the design can achieve the desired effect, and the design scheme is feasible.
Objective To evaluate surgical treatment of infected femoral artery pseudoaneurysm. Methods The data on surgical treatment of 45 patients with infected femoral artery pseudoaneurysm admitted from January 2003 to June 2008 were analyzed retrospectively. Fourty-three patients underwent operative treatment including excision of infected femoral artery pseudoaneurysm, exhaustive debridement and bypass graft with vascular prosthesis. Two patients were unavoidable to undergo removing of infected femoral artery pseudoaneurysm and ligating the proximal and distal artery of pseudoaneurysm because of severe infection and large volume. Results The patients were followed up from 3 to 12 months (mean 7.82 months). The limbs of all the patients underwent bypass graft with vascular prosthesis were salvaged successfully, patients of which had secondary wound healing and had not intermittent lameness. One of two patients performed ligation of artery was salvaged successfully but had severe intermittent lameness, another patient underwent high amputation above knee because of ischemic gangrene. Conclusion For infected femoral artery pseudoaneurysm, the operative treatment including excision of infected femoral artery pseudoaneurysm, exhaustive debridement and bypass graft with vascular prosthesis is effective and safe.
Objective To discuss the clinical application of preserving femoral neck in total hip arthroplasty and to analyze the early stage results.Methods From January 1999 to June 2001, 12 patients underwent total hip arthroplasty with preservation of femoral neck. We cut off the femoral head in infra-head position with improved Moore micro-incisions to reserve intact neck of femur. Thensuitable size of extra cup was selected and placed at 55° eversion angle. The internal cup, made from ultra high polymer poly thene and with ultra radius design, was placed at 45°eversion angle. Harris scores were recorded before operation, after operation and during the follow-up. During the follow-up, the X-rayfilms were taken to assess position, loosening of the prosthesis and ectopic ossification.Results All 12 patients were followed up 2-4.5years with an average of 3.1 years. The mean Harris score of hip elevated from 54 scores before operation to 92 scores of the last follow-up. Mild ectopic ossification occurred in 3 cases. There was no prosthesis loosening and femoral prosthesis setting, and only onepatient had mild bone absorption around femoral prosthesis.Conclusion Total hip arthroplasty with femoral neck preservation is a good option for the patients who need total hip arthroplasty for variable reasons, which is indicated for the patients whose femoral neck is intact with no osteoporosis.
Objective To investigate the key parameters of three-dimensional anatomy of the proximal humerus and compare the differences between male and female, and between left and right sides in Chinese by volume rendering technique with multi-slice spiral CT (MSCT) so as to provide a reference for a new prosthesis of the proximal humerus which can adjust to the anatomical characteristics of Chinese. Methods A total of 100 healthy volunteers were collected from Chongqing of China, including 59 males and 41 females with an average age of 40.4 years (range, 21-57 years). The humeral retroversion angle (RA), neck-shaft angle (NSA), medial offset (MO), and posterior offset (PO) were measured by volume rendering technique with MSCT. The average values were compared between male and female and between left and right sides, the correlation of these parameters was also analysed. Results In 100 volunteers (200 sides), the RA was (19.9 ± 10.6)°, the NSA was (134.7 ± 3.8)°, the MO was (4.0 ± 1.1) mm, and the PO was (2.6 ± 1.3) mm. There were significant differences in RA and MO between left and right sides (Plt; 0.05); there was no significant difference in NSA and PO between left and right sides (P gt; 0.05). The PO and RA of both sides in male were significantly larger than those in female (P lt; 0.05); the NSA and MO in male were similar to those in female (P gt;0.05). PO was correlated positively with RA (r=0.617, P=0.000); MO was not correlated with NSA (r= —0.124, P=0.081). Conclusion Because of significant side differences in RA and MO, and significant gender differences in RA and PO, the differences should be considered in the design of new proximal humeral prosthesis and proximal humerus reconstruction.
【Abstract】 Objective To study the influence of close-box and open-box knee prosthesis on postoperative bloodloss in patients undergoing total knee replacement(TKR). Methods From June 2005 to December 2006, 108 atients with primaryknee osteoarthritis were treated with TKR. Closed-box knee prosthesis was used in 54 patients (Group A), including unilateral(Group A1, n =27)and bilateral (Group A2, n =27). There were 7 males and 47 females, aged 41-76 years; and the diseasecourse was 4-16 years. Open-box knee prosthesis was used in 54 patients(Group B), including unilateral (Group B1, n =27)andbilateral(Group B2, n =27). There were 8 males and 46 females, aged from 59-81 years; and the disease course was 8-26 years. Thepostoperative blood loss and perioperative blood loss were compared between groups. Results The postoperative blood losswas (890±352), (1 694±528), (1 068±386) and(2 065±622) mL in groups A1, A2, B1 and B2, respectively. There was no significantdifference between groups A1 and B1(P gt; 0.05). There was significant difference between groups A2 and B2(P lt; 0.05). The totalblood loss was (1 095±329), (2 082±594), (1 274±415) and (2 459±734) mL in groups A1, A2, B1 and B2, respectively. Therewas no significant difference between groups A1 and B1(P gt; 0.05). There was significant difference between groups A2 and B2(P lt; 0.05). Conclusion Closed-box knee prosthesis may play roles on reducing postoperative blood loss. The main influentialfactor for postoperative blood loss is operation techniques which includes reducing operation time and stanching thoroughlyduring operation.
Objective To discuss the endothelial cell which was modified by exogenous anticoagulant genes contribute to the increase of antithrombosis activity of lined vascular prosthesis and the influence to other physiological functions of endothelial cells. Methods This summarized paper was made on literature review of recent years. Results The transfection of genes, including plasminogen activator (tPA, uPA, Urokinase), thrombomoduline (TM) and hirudin, etc, to endothelial cells resulted in not only the increase of antithrombosis activity of local vascular, but also the decrease of endothelial cell function in adherence and proliferation. Conclusion The increase of antithrombosis activity of lined vascular prosthesis has been done by exogenous genes. However, this technique ought to be studied, intensively.
ObjectiveTo observe the morphological and pathological changes after transplantation of polytetrafluoroethylene (PTFE) in vivo. MethodsPTFE microporous polypropylene tube which was encircled by spiral steel wire was used to prepare the artificial trachea.Forty New Zealand white rabbits (weighing,4-5 kg) were selected,and were divided into 2 groups.After the cervical trachea (2 cm in length) was removed,the end-to-end anastomosis between the trachea and PTFE artificial trachea was performed in the experimental group (n=20),and end-to-end anastomosis of the trachea in the control group (n=20).The survival of the rabbits was observed after operation;the X-ray,gross,and histological observations were carried out at 2,4,and 6 months after operation.The longitudinal tensile and radial support biomechanical tests were performed before and after transplantation. ResultsThe survival time was more than 2 months and the artificial airway was patency in 15 rabbits of the experimental group;the tissue outside the artificial trachea was like tracheal tissue,which filled in the defect,but it was more than 4 months.X-ray observation showed that the PTFE artificial trachea had no obvious displacement in the experimental group,and no tracheostenosis was observed in the control group.After 2 months,there was no epithelial tissue on the artificial airway wall;after 4 months,there was some epithelial cells on the artificial airway wall,incomplete endothelialization and trachea layer structure were seen with no tracheal ciliated columnar epithelium;after 6 months,the artificial trachea wall was covered with epithelium basically,and some ciliated columnar epithelium cells were found,which had the physiological function of the trachea.The transplanted PTFE artificial trachea could keep the stability of the biological mechanics performance,and could be used for the rabbit tracheal reconstruction. ConclusionPTFE artificial trachea can induce to form a tracheal tissue in the trachea tissues of recipients,each layer of the trachea is relatively complete and the experiment animals can be short-term survival.
Abstract： Objective To investigate the early and mid-term outcomes of morphologic tricuspid valve replacement by means of intravalvular implantation in corrected transposition of great arteries（cTGA）. Methods From January 2009 to January 2012，11 patients with cTGA were surgically treated in Fu Wai Hospital. There were 9 male patients and 2 female patients with their mean of age of（37.8±11.7）years and mean body weight of（73.0±11.3）kg. All the patients underwent morphologic tricuspid valve replacement with preservation of the entire valvular and subvalvular apparatus. Simultaneous surgical procedures included repair of ventricular septal defect in 2 patients，repair of atrial septal defect in 4 patients，pulmonary valvuloplasty in 1 patient，reconstruction of functional right ventricular outflow tract in 4 patients and repair of coronary-pulmonary artery fistula in 1 patient. Postoperative New York Heart Association （NYHA） classification, cardiothoracic ratio, morphological right ventricle ejection fraction, end-diastolic dimension of morphological right ventricle and left atrium were evaluated during follow-up. Results All the 11 patients were successfully surgically treated and followed up for an average duration of（13.0±10.6）months. There was no statistical difference between postoperative and preoperative average cardiothoracic ratio （0.54±0.06 vs. 0.57±0.09，t=1.581，P＞0.05），morphologic right ventricle ejection fraction （52.8%±9.0% vs. 54.9%±9.5%, t =0.712，P＞0.05），and end-diastolic dimension of . morphological right ventricle （54.3±7.5 mm vs. 56.9±9.2 mm，t =0.988，P＞0.05）. There was statistical difference between postoperative and preoperative average end-diastolic dimension of left atrium（42.1±8.9 mm vs. 53.4±11.1 mm，t =3.286，P＜0.05）and NYHA classification（Z = -2.640，P＜0.05）. Conclusion Intravalvular implantation of morphologic tricuspid prosthesis can protect the physiological structure of morphologic right ventricular and prevent furtherdamage to its function caused by morphologic tricuspid valve insufficiency. Postoperative dimension of morphologic left atrium and cardiac function are significantly improved. The early and mid-term outcomes are satisfactory．
Objective To analyze the outcomes and complications after total knee replacement(TKR) with posterior stabilized prosthesis(PS) and to investigate the influencing factors relating to outcomes. Methods From January 1998 to August2004, 60 cases (74 knees) of osteoarthritis underwent TKR with PS. The outcomeswere evaluated according to the HSS(hospital for special surgery) scoring. The difference in outcomes between patients with post-operative complications and without complications were compared. Pearson correlation was used to analyze post-operative outcomes and the pre-operative factors relating to patients. Results All 74 knees werefollowed up 42.5months(24 to 94 months). The scores for HSS, pain, function, ROM muscle strength, flexion deformity and stability of knees after operation were 84.2±14.2, 25.7±6.9, 17.9±4.3,13.1±2.0，9.2±0.8，8.1±0.4 and 9.3±0.1 respectively. They were improved to some extents, especially pain alleviation was remarkable. The excellent and good rate for outcome assessment was 90.5%. Among 74 knees, 10 cases suffered from postoperative complications, including 1 case of common peroneal nerve paralysis, two cases of wound faulty union, one case of wound infection, one case of joint infection, one case of stiff knee, two cases of deep vein thrombosis and 2 cases of patellofemoral joint complications. The excellent and good rate of outcome in patients with complications(60%) was much lower than that in patients without complication(95.3％),and there was significant difference betweenthem (P＜0.05). Analysis for correlation showed that postoperative HSS score was positively correlative with the postoperative HSS score, pain and function score of knees. The correlation value was 0.523，0.431 and 0.418 respectively(Plt;0.01). Whereas, postoperative HSS score was not correlative with ROM, muscle strength, flexion deformity, stability of knee, age, weight andbody mass index(P＞0.05). Conclusion TKR with PS is an effective method for severe osteoarthritis. The outcomes after TKR have a positive correlation with the HSS score, pain and function score of knees before surgery. Complicationsassociating with surgery have a negative influence on outcomes.
Objective To evaluate the biocompatibility and in vivo degradation of novel chest wall prosthesis materials and provide some data for their clinical application. MethodsAccording to the standard for the biological evaluation of the medical devices, several tests were performed to evaluate the tissue toxic effects induced by polydioxanone (Group A), chitosan (Group B), and hydroxyapitite/collagen (Group C),which were tested as component materials of the chest wall prosthesis. In the hemolysis test, 0.2 ml of the anticoagulant rabbit blood was added to the component materials and the normal saline (negative control) and to the distilled water(positive control). Five samples were made in each group. Absorbency was measured and the hemolysis rate was determined. In the acute systemic toxicity test, 20 mice were randomly divided into 4 groups (Groups A, B and C, and the normal saline group, n=5). The leaching liquid (50 ml/kg) was injected through the caudal vein, which was observed at 24, 48 and 72 hours. In the pyrogen test, 12 rabbits were randomly divided into 4 groups (Groups A, B, C and the normal saline group, n=3) the leaching liquid(10 ml/kg) was injected through the ear vein,and the body temperature was recorded within 3 hours. In the in vivo degradable test, the component materials (10 mm×10 mm) were implanted in 12 rabbits at 2, 4, 8, 12, 16 and 24 weeks, respectively, after operation. Two rabbitswere sacrificed for the macroscopic and the microscopic examinations. Results The chest wall component materials had no hemolytic reaction, no acute systemic toxicity, and no pyrogen reaction. The results demonstrated that the implanted materials had only a mild inflammatory reaction during the early days of the grafting, which subsided gradually. There was no tissue denaturation, necrosis or pathological hyperplasia when the prosthesis materials were degraded. Conclusion The degradable materials of the chest wall prosthesis have a good biocompatibility and agreat biological safety though their surgical application still requires a further clinical research.