Objective
To investigate the impact of difference between the medial and lateral posterior condyle cartilage thickness on osteotomy in total knee arthroplasty (TKA) by measuring the thickness of the medial and lateral femur posterior condylar cartilage and the posterior condylar angle (PCA) in osteoarthritis (OA) patients.
Methods
Between May and December 2011, 53 OA patients (60 knees) scheduled for TKA met the inclusion criteria (OA group). There were 12 males (14 knees) and 41 females (46 knees), aged 57-82 years (mean, 71.9 years). The tibiofemoral angle was (183.2 ± 2.6)
°
. Fifteen healthy volunteers (30 knees) were taken as controls (control group); there were 6 males and 9 females, aged 59-68 years (mean, 66.3 years). MRI scan data were imported into Mimics10.01 medical image control system to measure the thickness of femur posterior condylar cartilage and the PCA with and without femur posterior condylar cartilage.
Results
In the control group, the thickness of the medial and lateral femur posterior condylar cartilage was (1.85 ± 0.33) mm and (1.92 ± 0.27) mm respectively, the PCA with and without femur posterior condylar cartilage was (5.0 ± 0.9)° and (5.1 ± 0.8)° respectively, all showing no significant differences (P gt; 0.05). In OA group, the thickness of the medial and lateral femur posterior condylar medial cartilage was (0.45 ± 0.40) mm and (1.78 ± 0.51) mm respectively, the PCA with and without femur posterior condylar cartilage was (3.3 ± 1.7)° and (4.8 ± 1.8)° respectively, all showing significant differences (P lt; 0.05). In OA group, the difference between lateral and medial cartilage thickness was (1.33 ± 0.45) mm, and the difference between PCA with and without femur posterior condylar cartilage was (1.5 ± 1.3)°. There was a positive correlation between the difference of cartilage thickness and the difference of PCA (r=0.75, P=0.01).
Conclusion
There is significant difference between medial and lateral femur posterior condylar cartilage wear, which leads to difference of PCA. The difference will impact knee function and longevity of the prosthesis, so the difference should be considered during osteotomy.
ObjectiveTo evaluate the clinical value of multi-slice CT in the diagnosis of complications due to breast augmentation.
MethodsWe collected the imaging data of 32 female patients who accepted multi-slice CT examination in the second People's Hospital of Chengdu after breast augmentation between February 2010 and February 2015. The position, shape, edge, internal density, leakage, rupture and hard nodules of the prosthesis were observed and analyzed carefully.
ResultsIn the 32 patients with breast augmentation, 12 were normal with bilateral symmetry and without abnormal shape or density. Among the other 20 patients, 11 had capsular contracture, 5 had prosthesis leakage, rupture and hard nodules, 4 had breast infection, 1 had fibroadenoma, 1 had cystoma, and 5 had little calcified nodules in the breast tissue.
ConclusionThe multi-slice CT scan can clearly and accurately show the position, shape and size of the breast prosthesis as well as the existence of leakage, rupture and hard nodules in the prosthesis. It plays a very important role in the diagnosis of the complications due to breast augmentation and can be effective guidance for clinical operation.
ObjectiveTo explore the association between wearing dentures and the risk of head and neck cancer using meta-analysis.
MethodsPubMed, EMbase, CNKI, and WanFang Data were searched up to April 30th, 2014, for cohort studies and case-control studies about the association between wearing dentures and the risk of head and neck cancer. Literature screening according to the inclusion and exclusion criteria, data extraction and methodological quality assessment of included studies were completed by two reviewers independently. Then meta-analysis was conducted using Comprehensive Meta-Analysis v 2.2 software.
ResultsEight case-control studies in 7 reports were finally included. The results of meta-analysis revealed that, low-degree association existed between wearing dentures and the risk of head and neck cancer (OR=1.08, 95%CI 1.00 to 1.16); and the results of further subgroup analysis (according to gender, cancer lesions, confounders adjustment, and publication years) also showed no significant difference.
ConclusionWearing dentures is not significantly associated with the risk of head and neck cancer (no difference regarding gender or cancer lesions). Due to limitations of this meta-analysis, high-quality studies with large sample size are needed to further verify the above conclusion.
Objective To review the progress and application of peripheral nervous microelectrode. Methods The recent articles on peripheral nervous microelectrode were extensively reviewed. The classification, the progress of the peripheral nervous microelectrode and its utilizable prospect in the control of electronic prosthesis were summarized. Results The microelectrodes had favorable functions of selective stimulation and recording. It provided an information transmitting interface between the electric prosthesis and peripheral nerves. Conclusion Peripheral nervous signal is a feasible signal source to control electronic prosthesis.
Abstract: Objective To investigate the in vivo effective orifice area (EOA) and whether prosthesispatient mismatch (PPM) is going to happen after 19mm St.Jude Regent valves replacement were performed. Methods Twentythree patients with valvular heart diseases were divided into 2 groups according to aortic annular diameter. 19mm St. Jude Regent valves were replaced in aortic valve place (Regent valve group), and 21mm other doubleleaflet mechanical valves were replaced in aortic place (other valves group). All of the operations were accomplished under cardiopulmonary bypass in West China Hospital. All of the patients were followed up in 3 to 6 months after their surgery processes. Color Doppler echocardiography was used to measure the hemodynamic parameters in their followup. Then left ventricular mass (LV mass), EOA and effective orifice area index (EOAI) etc. were calculated and compared by using SPSS 12.0. Results No cardiac episodes were detected during the perioperative period and 36 months after operation. LVmass reduced in 36 months after operation in both groups. No statistical significance of EOA, EOAI and LVmass reduction were detected between the two groups. Conclusions (1)The EOA and in vivo hemodynamic effects of 19mm Regent valve are similar to 21mm other double leaflet mechanical valve. (2)It is safe to use 19mm Regent valve in those patients whose aortic annular diameter are small and need double valve replacement. Using 19mm Regent valve will not cause short time cardiac episodes and PPM. (3)More further works should be done to make sure what is the standard of PPM in Chinese people, such as enlarging the patients number and prolonging the followup time. (4) Further clinical and followup works should be done to make St.Jude Regent valve’s feature out.
Objective To summarize and analyze the operation-correlated compl ications of total knee arthroplasty (TKA)with posterior stabil ized prosthesis (PS). Methods From October 2000 to October 2007, 707 cases (816 knees) underwent TKA. All the TKA knees were divided equally into former and latter groups according to the operation time (408 knees for each group). In the former group (October 2000 to January 2005, n=350), there were 63 males (84 knees) and 287 females (324 knees), aging (63.5 ± 7.8) years. A total of 198 left knees affected and 210 right knees affected; 292 single kneesaffected and 58 both knees affected. There were 304 knees of osteoarthritis, 84 knees of rheumatoid arthritis and 20 knees of other disease. The disease course was (9.3 ± 5.6) years. The knee range of motion (ROM) was (97.2 ± 8.7)°, the HSS score was 47.4 ± 12.2. In the latter group (January 2005 to October 2007, n=357), there were 77 males (92 knees) and 280 females (316 knees), aging (62.7 ± 6.3) years. A total of 221 left knees affected and 187 right knees affected; 306 single knees affected and 51 both knees affected. There were 278 knees of osteoarthritis, 109 knees of rheumatoid arthritis and 21 knees of other disease. The disease course was (8.6 ± 5.1) years. The knee ROM was (101.1 ± 10.3)°, the HSS score was 49.3 ± 11.2. We modified the method of lateral patellar retinaculum release and used a new femoral rotational al ignment technique in the latter group. The intraoperative and postoperative compl ications were divided into mild, moderate and severe. The HSS score, ROM and compl ications of the knee were compared and analyzed statistically during the follow-up. Results The former group was followed up 5.3 years (1 to7 years), compl ications occurred in 278 knees (68.1%), including mild in 136 knees (33.3%), moderate in 135 knees (33.1%) and severe in 7 knees (1.7%). The latter group was followed up 2.1 years (0.5 to 3.5 years), compl ications occurred in 159 knees (39.0%), including mild in 111 knees (27.2%), moderate in 47 knees (11.5%) and severe in 1 knee (0.2%), and there was significant difference between them (P lt; 0.001). There was significant difference in increased ROM between the former group (6.0 ± 3.7)° and the latter group (14.4 ± 4.2)° after operation (P lt; 0.05). There was significant difference in increased HSS score between the former group (36.9 ± 3.7)and the latter group (44.0 ± 4.2) after operation (P lt; 0.05). Conclusion The TKA is a complex operation with innumerable potential compl ications. To accumulate operative experience and improve surgical skills are the key points to reduce the operation-correlated compl ications.
Objective To introduce the occurrence mechanisms, prevention, and treatment measures of prosthetic aseptic loosening. Methods The recent original articles about prosthetic aseptic loosening were extensively reviewed and analyzed. Results Prosthetic aseptic loosening was a very complex process involving many mechanical and biological aspects. The main mechanical factors included prosthetic materials, shapes and sizes, implant fixation methods (including surfacetreatments), cl inical installation, interface micromotion, stress shielding, implant wear, interface integrity, and peri prosthetic high hydraulic pressure, etc.; the main biological factors included the types and sizes of wear particles, cell-activated responses, cytokine release, enzyme activation and allergic reactions to wear particles, etc.. Many measures should be adopted to effectively prevent and treat it, including improving materials and designs of prostheses, fixation techniques, surgical techniques, and drug treatments. Conclusion Prosthetic aseptic loosening is still a troublesome compl ication after joint replacements in orthopaedics, and more attention should be paid for its effective prevention and treatment.
ObjectiveTo investigate hemodynamic changes in the early postoperative period of isolated aortic valve replacement (AVR) with different types of 19-mm mechanical heart valves.
MethodsClinical data of 116 patients with aortic stenosis who underwent AVR in Beijing Anzhen hospital from January 2007 to January 2012 were retrospectively analyzed. There were 61 male and 55 female patients with their age of 52±13 years. All the patients were divided into 3 groups according to different types of mechanical heart valves they received. In SJ. Regent valve group,there were 38 patients (33%) including 20 males and 18 females with their average age of 52±15 years. In Carbomedics valve group,there were 40 patients (34%) including 21 males and 19 females with their average age of 51±17 years. In On-X valve group,there were 38 patients (33%) including 20 male and 18 female patients with their average age of 55±16 years. Preoperative and postoperative left ventricular end-systolic diameter (LVESD) left ventricular end-diastolic diameter (LVEDD) ejection fraction (EF) interventricular septal thickness,left ventricular wall thickness,trans-aortic valve velocity and pressure,and postoperative effective orifice area index (EOAI) were compared.
ResultsThere was no statistical difference in preoperative and postoperative LVESD,LVEDD,EF,interventricular septum thickness and left ventricular wall thickness among the 3 groups (P>0.05). There was statistical difference in preoperative and postoperative trans-aortic valve velocity and pressure. Trans-aortic valve velocity of SJ. Regent valve group and Carbomedics valve group (244.30±33.67 cm/s vs. 249.69±79.13 cm/s vs. 294.83±52.05 cm/s) and trans-aortic valve pressure of SJ.Regent valve group and Carbomedics valve group (27.77±3.33 mm Hg vs. 33.58±18.90 mm Hg vs. 38.56±13.21 mm Hg) were significantly smaller than those of On-X valve group.
ConclusionSt. Regent and Carbomedics mechanical heart valves demonstrate better hemodynamics in AVR patients receiving 19-mm mechanical heart valves.
In unicompartmental replacement surgery, there are a wide variety of commercially available unicompartmental prostheses, and the consistency of the contact surface between the common liner and the femoral prosthesis could impact the stress distribution in the knee after replacement in different ways. Medial tibial plateau fracture and liner dislocation are two common forms of failure after unicompartmental replacement. One of the reasons is the mismatch in the mounting position of the unicompartmental prosthesis in the knee joint, which may lead to failure. Therefore, this paper focuses on the influence of the shape of the contact surface between the liner and the femoral prosthesis and the mounting position of the unicompartmental prosthesis on the stress distribution in the knee joint after replacement. Firstly, a finite element model of the normal human knee joint was established, and the validity of the model was verified by both stress and displacement. Secondly, two different shapes of padded knee prosthesis models (type A and type B) were developed to simulate and analyze the stress distribution in the knee joint under single-leg stance with five internal or external rotation mounting positions of the two pads. The results showed that under a 1 kN axial load, the peak contact pressure of the liner, the peak ACL equivalent force, and the peak contact pressure of the lateral meniscus were smaller for type A than for type B. The liner displacement, peak contact pressure of the liner, peak tibial equivalent force, and peak ACL equivalent force were the smallest for type A at 3° of internal rotation in all five internal or external rotation mounting positions. For unicompartmental replacement, it is recommended that the choice of type A or type B liner for prosthetic internal rotation up to 6° should be combined with other factors of the patient for comprehensive analysis. In conclusion, the results of this paper may reduce the risk of liner dislocation and medial tibial plateau fracture after unicompartmental replacement, providing a biomechanical reference for unicompartmental prosthesis design.
Abstract: Objective To compare the change of left heart funct ion in pat ients w ith bio logical valves replacement of small ao rt ic roo t w ith mechanical valve rep lacement, and to find w hether there is p ro sthesis-patient mismatch (PPM ) or not after operation. Methods Left ventricular ejection fraction (LV EF ) , left ventricular fractional shortening (LVFS) , left vent ricular mass index, the indexed effective orifice area (EOA I) , and peak pressure gradients across aortic valve in 20 patients with small aortic root (≤21mm in diameter) receiving biological valves rep lacement (biological valves group ) were studied by Doppler echocardiography before the operation and 6 months to 1 year after operation. The results were compared with those of 20 patients who received mechanical valves replacement (mechanical valves group ). Results Comparing with those before operation, there was a significant increase in LVEF, LV FS, EOAI of all patients 6 months to 1 year after operation . There was a significant reduction in the left ventricular mass index, peak pressure gradients across aortic valve in all patients. EOAI of all patients were between 0.88 cm2/m2 and 1. 32 cm 2/m 2. LVEF, LVFS, EOAI, left ventricular mass index, and peak pressure gradients across aortic valve between biological valves group and mechanical valves group (79% ±8% vs. 81%±10%; 43%±9% vs. 37%±8%; 1. 11±0. 14 vs. 0. 92±0. 11; 89. 10±16. 70g/m 2 vs. 95. 30±15.10 g/m 2; 18. 80±12. 60 mmHg vs. 22. 30±12. 00 mmHg) showed no significant difference 6 months to 1 year after operation (P gt;0.05). Conclus ion Patients with small aortic root receiving biological valves have a significant increase in the left heart function, and have no PPM.
