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find Keyword "Prosthesis" 31 results
  • INFLUENCES OF PREOPERATIVE SEVERE LOWER LIMB DEFORMITY ON PROSTHESIS INSTALLATION AND ALIGNMENT RESTORATION IN TOTAL KNEE ARTHROPLASTY

    ObjectiveTo investigate the effect of preoperative valgus or varus deformity on the prosthesis installation and alignment restoration in total knee arthroplasty (TKA). MethodsBetween January 2012 and December 2013, 198 patients (245 knees) with osteoarthritis underwent primary TKA, and the clinical data were retrospectively analyzed. There were 23 males and 175 females, with the average age of 67 years (range, 43-90 years). Single knee and double knees were involved in 151 and 47 cases respectively. The disease duration was from 1 month to 30 years (mean, 8.99 years). The anteroposterior X-ray films of whole lower limbs were taken, and the femorotibial angle (FT) was measured before operation and at 1 week after operation; the mechanical femoral angle (MF) and the anatomical tibial angle (AT) at 1 week after operation were measured. The correlation analysis was made for pre-and post-operative FT, MF, and AT. According to the valgus or varus deformity before operation, all patients were divided into 5 groups:≥20° varus (group A), 10-20° varus (group B), ≤10° varus (group C), < 10° valgus (group D), and≥10° valgus (group E), and the above indicators were compared between groups. And the rate of the good limb alignment was recorded after operation. ResultsThe pre-and post-operative FT were (171.53±9.12) and (177.38±3.57)° respectively, and postoperative MF and AT were (89.00±2.68) and (88.62±2.16)° respectively. Preoperative FT was associated with postoperative FT and MF (r=0.375, P=0.000; r=0.386, P=0.000), but it was not correlated with AT (r=0.024, P=0.710). Postoperative FT was associated with MF and AT (r=0.707, P=0.000; r=0.582, P=0.000). Postoperative FT was significantly increased when compared with preoperative FT in each group (P < 0.05). There were significant differences in preoperative FT between groups (P < 0.05). There were significant differences in postoperative FT when compared group A with groups B, C, D, and E (P < 0.05), and when compared groups B and C with groups D and E (P < 0.05), but there was no significant difference between groups B and C, and between groups D and E (P>0.05). The rate of good alignment was 70.2% (172/245); it was 27.8% (5/18), 66.0% (62/94), 74.4% (67/90), 88.9% (32/36), and 85.7% (6/7) in groups A, B, C, D, and E respectively, showing significant differences between groups (P < 0.05). There was no significant difference in postoperative AT between groups (P>0.05). Except for between group D and group E (P>0.05), significant difference in MF was shown between the other groups (P < 0.05). ConclusionThe more severe deformity of lower limb before TKA, the higher risk of deviation for prosthesis installation and poor alignment in TKA.

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  • PHOTOELASTIC STUDY OF FRACTURE OF PROSTHETIC STEM AFTER FEMORAL HEAD REPLACEMENT

    Abstract The fracture of the prosthetic stem after prosthetic replacement of femoral head is not rare. In this study, the photoeastic instrument was used to study the stress distribution on the prosthetic stem following its insertion and to analyse the factors influencing the fracture of the stem. Through the examination of 9 places in 8 cases, it was found that:(1) The removal of femoral calcar and the inframedullary filling of the bone cement directly influenced the stress distribution. (2) The valgus or varus condition of the prosthesis would lead to stress concentration on the stem. (3) Once lossening of the prosthesis occured it would change the preliminary installingstress distribution in the upper femur which would lead to fatigue fracture. Ths experimental data and clinical observation would provide scientific basis forthe prevention of fracture of prosthetic stem following prosthetic replacement of femoral head.

    Release date:2016-09-01 11:10 Export PDF Favorites Scan
  • Application of Preperitoneal Tension-Free Repair in Inguinal Hernia by Easy Prosthesis D-10

    Objective To evaluate the clinical effect of Easy Prosthesis D-10 on open preperitoneal groin tension-free hernioplasty. Methods The operative time, operation-correlated complications, hospital stay and recent follow-up findings of 63 patients underwent preperitoneal groin tension-free hernioplasty were analyzed from October 2006 to April 2008. Results No case died in perioperative period. The average operative time was (47.6±10.5) minutes. None of incision infection and scrotal hydrocele occurred. The average hospital stay was (7.7±2.1) days. During follow-up period of 6 to 24 months, no recurrence, chronic pain and foreign body sensation were found. Conclusion The open preperioneal groin tension-free hernioplasty by Easy Prosthesis D-10 is safe and reliable, especially for the inguinal hernia with large hernia ring or defect of transversalis fascia and recurrent hernia.

    Release date:2016-09-08 10:57 Export PDF Favorites Scan
  • Compar ing Study of Heart Function of Biolog ical Valves Replacemen t with Mechan ical Valves Replacemen t in Patien ts with Small Aortic Root

    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.

    Release date:2016-08-30 06:08 Export PDF Favorites Scan
  • Finite element analysis of the effect of knee movable unicompartmental prosthesis insertion shape and mounting position on stress distribution in the knee joint after replacement

    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.

    Release date:2022-10-25 01:09 Export PDF Favorites Scan
  • ADVANCEMENT IN TOTAL KNEE PROSTHESIS SELECTION

    Objective To discuss the recent advancement of total knee arthroplasty (TKA) in the aspects of prosthesis selection, and compare the cl inical effect of every kind of knee prostheses so as to provide more information for cl inical appl ication. Methods The l iterature concerning prosthesis selection was extensively reviewed, and the methods and data were analyzed and summarized. Results The major disputes consisted of posterior cruciate retained versus excised,fixed-bearing versus mobile-bearing, high-flex versus standard implants and patella resurfacing versus nonresurfacing for TKA. Every kind of knee prostheses displayed safety and effectiveness in early and medium term follow-up, no significant differences were found in cl inical results. Conclusion Prosthesis selection in TKA should be overall considerated, and the merits of every kind of prostheses should be judged with long-term follow-up results.

    Release date:2016-08-31 05:47 Export PDF Favorites Scan
  • RESECTION OF NERVE OF WRIST COMBINING REPLACEMENT OF LUNATE WITH BONE CEMENT PROSTHESIS IN TREATMENT OF KIENBOCK S DISEASE

    OBJECTIVE There are various methods used to treat the Kienbock’s disease with various outcomes. This study investigated the effect of combining acrylic lunate prosthesis replacement with resection of articular branches to wrist from anterior and dorsal interosseous nerve. METHODS From January 1992 to January 1997, six cases were included. All of the patients were in stage III according to Lichtman’s classification. Besides replacement of the acrylic lunate prosthesis, segment of the pure sensory branches from anterior and posterior interosseous nerves were resected. RESULTS Follow-up for 10 to 54 months (an average of 32 months) the pain was relieved in all patients except one. The range of movement of wrists were as followings: The extension of the wrist was 20 to 35 degrees (an average of 26 degrees) and flexion was 20 to 35 degrees (an average of 32 degrees). There was no improvement in radial and ulnar deviation. CONCLUSION Lunate prosthesis replacement combined with resection of articular branches to wrist resulted in a painless wrist and was a satisfactory method.

    Release date:2016-09-01 11:05 Export PDF Favorites Scan
  • AN ANALYSIS OF OPERATION-CORRELATED COMPLICATIONS OF TOTAL KNEE ARTHROPLASTY

    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.

    Release date:2016-09-01 09:05 Export PDF Favorites Scan
  • Association between Wearing Dentures and Risk of Head and Neck Cancer: A Meta-Analysis

    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.

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  • ABSTRACTSTREATMENT OF PROSTHESIS REPLACEMENT FOR MALIGNANT TUMOR OF THEPROXIMAL HUMORAL

    After freatment of prosthesis replacement for 12 malignant tumer of the proximal humoral werereported. The operation were performed after the indications and methods of treatment had beendefined. All of the 12 cases were followed-up, in the average of 8 yeare. On functional evaluation , 8cases had satisfactory result , but per in 1 cases and 3 cases died from recurrence or metastasis withinfive years. The indieation of the procthetic replantation, the complications, and revision weredisecused.

    Release date:2016-09-01 11:32 Export PDF Favorites Scan
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