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Total knee replacement is an effective method to treat serious knee joint diseases.The rapid development in the technology of artificial knee joints has led to a quickly increasing number of knee replacement surgeries.The clinical results of total knee arthroplasty depend on many factors.These factors include the surgical technique,selection of the patient and design of the prosthesis.Recent development of Chinese artificial knee joints will eventually put these products into the international markets.Before entering the international markets,it is necessary to fully understand the foreign medical regulations and laws,and to prevent from adverse events such as recall litigations,especially in Europe and America.Hence,the quality assurance system of the products and production management system should be promoted.Therefore,the experiences of famous international companies should be used to effectively improve the qualities of Chinese medical devices.The present article reviewed the recent recalls of products of five artificial knee prosthesis enterprises by the Food and Drug Administration (FDA) and analyzed the causes of product recalls and related literatures of adverse events in clinical use.
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Lumbar adjacent segment degeneration is defined as degenerative changes cranial or caudal to surgical segments.Some patients developed corresponding clinical symptoms in addition to radiological degeneration,which is called adjacent segment disease.Although many new surgical techniques emerged in recent years,the problem of adjacent segment degeneration has not really been resolved.MEDLINE/PubMed,Cochrane Controlled Trials Registry and EMBASE were comprehensively searched.All randomized or nonrandomized clinical studies of lumbar degenerative diseases treated by fusion/fixation,decompression-alone or artificial lumbar disc replacement were included.The number of cases enrolled in these studies was greater than or equal to 20 cases and the minimum age of the patients was 18 years old.Case reports,reviews or meta-analyses,papers with unobtainable text and abstract,and studies of trauma,infection,oncology and inflammatory disease were all excluded.The diagnostic criteria of adjacent segment degeneration,as well as the incidence and risk factors of adjacent segment degeneration and reoperation were reviewed.The concepts of adjacent segment degeneration in different literatures were very confusing,and radiological degeneration was often mixed in use with symptomatic degeneration.It was therefore difficult to make any conclusion due to lack of a standard.In addition,the previous studies did not fully understand the pathogenesis and risk factors of the disease,especially the effect of the index level on adjacent segments.Moreover,most of the current studies were retrospective,therefore,convincing conclusions can hardly be drawn due to lack of high-level evidence.The main reason for reoperation after lumbar fusion is adjacent segment degeneration.Therefore,the most important way to reduce the rate of reoperation is to reduce the incidence of adjacent segment degeneration.In the future,the diagnostic criteria for adjacent segment degeneration should be unified first.And it is extremely important to thoroughly understand the mechanism and risk factors of adjacent segment degeneration by comprehensive studies and clarify them through high-level evidence.
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PURPOSE: This study compared in vivo kinematic differences between Caucasian and South Korean patients after a posterior-substituting total knee arthroplasty (PS-TKA). MATERIALS AND METHODS: In vivo motions of 9 Caucasian and 13 South Korean knees with a PS-TKA during weight bearing single leg lunge were determined using a dual fluoroscopic imaging technique. Normalized tibiofemoral condylar motions and articular contact locations were analyzed. RESULTS: Femoral condylar motions of the two groups showed a similar trend in anteroposterior translation, but the South Korean patients were more anteriorly positioned than the Caucasian patients at low flexion and maximal flexion angles in both medial and lateral compartments (p<0.05). Mediolateral femoral condyle translations were similar between the two groups. For tibiofemoral articular contact kinematics, the South Korean patients had significantly more anterior contact locations at the medial compartment at low flexion angles, and more lateral contact locations at the lateral compartment at 0° and 90° flexion compared to the Caucasian patients (p<0.05). The South Korean patients had significantly larger distances between the medial and lateral contact locations at 60° and 90° flexion compared to the Caucasian patients (p<0.05). CONCLUSIONS: The study revealed that while the Caucasian and South Korean knees had similar femoral condylar motions, after PS-TKA the South Korean patients showed different articular contact point kinematics compared to the Caucasian patients.
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Humans , Arthroplasty , Arthroplasty, Replacement, Knee , Asian People , Biomechanical Phenomena , Knee , Leg , Lung , Translations , Weight-BearingABSTRACT
Anterior cruciate ligament is the most important ligament to maintain the anterior and rotation stability of knee joint. Rupture of anterior cruciate ligament is one of the most common injuries of knee joint, and thus leads to knee instability and traumatic osteoarthritis. Anterior cruciate ligament reconstruction is usually performed to restore the anterior stability of knee joint, and is considered to reduce the secondary injury of medial meniscus, lateral meniscus and cartilage. Thus anterior cruciate ligament reconstruction can improve the function of knee joint. Traditional single bundle technique to reconstruct anterior cruciate ligament has been performed for many years. This technique can restore the anterior stability of knee joint and has excellent clini?cal results. Nearly 61%patients showed obvious radiographic osteoarthritis 20 years after anterior cruciate ligament reconstruction using bone-patella-bone graft. But, there is no agreement regarding to reduce the development of osteoarthritis after reconstruc?tion of anterior cruciate ligament. However, it has been reported that osteoarthritis would develop after reconstruction of anterior cruciate ligament in long term follow up study. Recently, with the further understanding of anatomy of biomechanics of anterior cru?ciate ligament, new techniques for anterior cruciate ligament reconstruction are developed, such as double bundle reconstruction, anatomic reconstruction and individual reconstruction. It remains controversial that whether these new technique can prevent the development of osteoarthritis after rupture of anterior cruciate ligament. Currently, no reconstruction technique for anterior cruci?ate ligament is perfect, and every technique has advantages and disadvantages. In terms of reducing the prevalence of osteoarthri?tis after reconstruction of anterior cruciate ligament, which technique is the best still remains unclear. New treatment and evalua?tion methods should be developed. In the future, not only the restoration of stability of knee joint should be considered, but also the articular cartilage contact kinematics including tibiofemoral joint and patellofemoral joint after anterior cruciate ligament recon?struction. Reduction of the development of osteoarthritis is an important topic after reconstruction of anterior cruciate ligament.
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Several anatomical anterior cruciate ligament (ACL) reconstruction techniques have been proposed to restore normal joint kinematics. However, the relative superiorities of these techniques with one another and traditional single-bundle reconstructions are unclear. Kinematic responses of five previously reported reconstruction techniques (single-bundle reconstruction using a bone-patellar tendon-bone graft [SBR-BPTB], single-bundle reconstruction using a hamstring tendon graft [SBR-HST], single-tunnel double-bundle reconstruction using a hamstring tendon graft [STDBR-HST], anatomical single-tunnel reconstruction using a hamstring tendon graft [ASTR-HST], and a double-tunnel double-bundle reconstruction using a hamstring tendon graft [DBR-HST]) were systematically analyzed. The knee kinematics were determined under anterior tibial load (134 N) and simulated quadriceps load (400 N) at 0degrees, 15degrees, 30degrees, 60degrees, and 90degrees of flexion using a robotic testing system. Anterior joint stability under anterior tibial load was qualified as normal for ASTR-HST and DBR-HST and nearly normal for SBR-BPTB, SBR-HST, and STDBR-HST as per the International Knee Documentation Committee knee examination form categorization. The analysis of this study also demonstrated that SBR-BPTB, STDBR-HST, ASTR-HST, and DBR-HST restored the anterior joint stability to normal condition while the SBR-HST resulted in a nearly normal anterior joint stability under the action of simulated quadriceps load. The medial-lateral translations were restored to normal level by all the reconstructions. The internal tibial rotations under the simulated muscle load were over-constrained by all the reconstruction techniques, and more so by the DBR-HST. All five ACL reconstruction techniques could provide either normal or nearly normal anterior joint stability; however, the techniques over-constrained internal tibial rotation under the simulated quadriceps load.
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Anterior Cruciate Ligament , Anterior Cruciate Ligament Reconstruction , Biomechanical Phenomena , Bone-Patellar Tendon-Bone Grafts , Joints , Knee , Tendons , Translations , TransplantsABSTRACT
Objective To measure the range of motion (ROM) of the lumbar pedicle screw entrance point (LPSEP) in vivo during unrestricted motion under physiological weight bearing.Methods Eleven healthy volunteers aged 45-60 years underwent MRI scans in a supine position.Three-dimensional (3D) models of L2-5 were constructed.Next,each volunteer was asked to stand and was positioned in the following sequence:standing,45° flexion,maximal extension,maximal left-right twisting,while two orthogonal fluoroscopic images were taken simultaneously at each position.The MRI models were matched to the osseous outlines of the images from the two orthogonal views to determine the position of the vertebrae in 3D at each position.Coordinate systems were established to study the ROM of the LPSEP.Results The predominant translations were along anteroposterior and craniocaudal axis from supine to standing position (average,2.44mm and 2.35 mm).Rotation of the LPSEP occurred mainly around the mediolateral axis(average,3.91 °).During flexion-extension movements of the trunk,the predominant translation were along anteroposterior and craniocaudal axis and rotation were around mediolateral axis.During lateral bending and twisting,ROM of LPSEP did not rotate or translate in one dominant direction.Instead,the resulting motion represented a combination of rotation and translation in different directions.There was no significantly difference in translation and rotation between the three axis in L4,5segment (P＞0.05).Conclusion The kinematic behaviors of the LPSEP of the upper lumbar spine (L2,3 and L3,4) are similar which are different from that of the lower lumbar spine (L4,5).
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Objective To measure the vertebral rotational centers in sagittal and transverse plane. These data may be quite valuable for the design of artificial disc. Methods Ten healthy volunteers of 40-60 years old were recruited under IRB approval and informed consent. Three-dimension lumbar spine models of L_2, L_3 and L_4 were reconstructed from MR scans. Spine motions were then reproduced using combined dual fluoroscopic imaging system (DFIS) and MR scan technique during flexion-extension and left-right twisting of the body. Based on the geometrical features of the vertebrae, ranges of motion (ROM) of 3 representative lo-cations were measured from anterior to posterior, the vertebral body center, the spinal cord canal center and the spinous process tip. Rotational centers of the vertebral segments were then located by calculating the point of zero ROM. Results Motion patterns: The ROMs of L_2 with respect to L_3 (L_(2,3)) and L_(3,4) increased pro-portionally from anterior to posterior locations. During flexion-extension motion, the vertebral body center moved within a range of 0.6 mm, while the spinous process tip moved within 7.5 mm in the sagittal plane. During left-right twisting, the vertebral body center moved within 1.0 mm, while the tip moved within 1.6 mm in the transverse plane. No statistical differences were found in the ROMs between L_(2,3) and L_(3,4). Rotational centers: the rotational centers of flexion-extension in sagittal plane for both L_(2,3) and L_(3,4) segments were located at posterior one-third of the vertebral body. The rotational centers of both L_(2,3) and L_(3,4) segments were located approximately 30 mm anterior to the front edge of the vertebral body. Conclusion The anterior portion of the vertebrae was found to have smaller ROM than the posterior portion. The vertebra rotates with the center of rotation located at approximately the posterior one-third of the vertebral body in sagittal plane. However, the vertebra rotates in transverse plane with respect to a point about 30 mm in front of the vertebra. The data indicated that the different portions of the vertebra have distinct motion characters during different motions.
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Objective To investigate the prevalence and molecular epidemiology of clinical isolates of plasmid-mediated 16S rRNA methylases-producing Klebsiella pneumoniae. Methods From January 2006 and September 2007, 337 non-replicate clinical isolates of Klebsiella pneumoniae were consecutively collected from inpatients in a teaching hospital in Wenzhou, China. All of the isolates were identified by the automated microbiology systems. MICs of amikacin, gentamicin and tobramycin were determined by agar dilution method. The isolates were investigated for the presence of ESBLs by the CLSI-recommended confirmatory tests. PCR was used to detect 16S rRNA methylase genes, ESBL genes and class Ⅰ integrase gene. The homology of these isolates was analyzed by pulse-field gel electrophoresis (PFGE). Results Sixty-four ( 19. 0% ), 28 ( 8. 3% ) and 55 ( 16. 3% ) of 337 isolates were resistant to gentamicin, amikacin and tobramycin, respectively. Twenty-one (6. 2% ) isolates carried 16S rRNA methylase genes (3 for armA, 13 for rmtB, 5 for both armA and rmtB) and high-level resistant to gentamicin, amikacin and tobramycin ( MICs ≥256 mg/L). Nineteen of 21 isolates with 16S rRNA methylase genes were ESBL producers, blaCTX-M-14-like, blaCTX-M-like and blaSHV-12-like were predominant genotypes of ESBLs. The plasmids of 13 isolates were transferred into the recipients E. co/iJ53. PCR and sequence analysis revealed that blaCTX-M-14-like,blaCTX-M-15-like and blaSHV-12-like were co-transferred with the armA or the rmtB to the recipients. All transconjugants harbored intll and blaTEN-1. Of the 21 isolates, 14 patterns were obtained by PFGE. Conclusion Both horizontal gene transfer and clonal spread were responsible for the dissemination of the rmtB or the armA gene in Klebsiella pneumoniae.
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Objective To investigate the prevalence of aac(6')-Ib-cr in clinical isolates of Klebsiella pneumoniae.Methods A total of 337 isolates of Klebsiella pneumoniae were isolated from clinical specimens in our hospital from Jan,2006 to Sep,2007.Gentamycin,amikacin or tobramicin was used to screen the isolated with aac(6')-Ib-cr.aac(6')-Ib and class 1 interase gene(intl1)was determined by PcR All PCR products of aac(6')-Ib were sequenced for determination of aac(6')-Ib-cr. MICs of antibiotics were determined by agar dilution method.The ESBLs-producing isolates were determined by the CLSI-recommended confirmatory tests.Conjugation test was used to detect the transfer of plasmid.Results Of the 337 clinical isolates of Klebsiella pneumoniae,64(19.0%),28(8.3%)and 55(16.3%)isolates were resistant to gentamycin,amikacin and tobramycin,respectively.Among 64 gentamycin-resistant isolates,24(37.5%)were positive for aac(6')-Ib-cr,including 13 ciprofloxacin-resistant isolates and 11 ciprofloxacinsusceptible isolates.The prevalence of aac(6')-Ib-cr in ciprofloxacin-resistant and-susceptible isolates were 54.2%(13/24)and 27.5%(11/40).The positive rates of ESBLs and intl1 in the 24 isolates carrying aac(6')-Ib-cr were 79.2%(19/24)and 91.7%(22/24).Plasmids carrying aac(6')-Ib-cr of 13 isolates were successfully transferred to E.coli J53.Plasmids of all transconjugants were positive for aac(6')-Ib-cr and intl1.All transconjugants were ESBL producing strains.Conclusions aac(6')-Ib-cr exists widely in clinical isolates of Klebsiella pneumoniae.aac(6')-Ib-cr and ESBL gene usually coexist in a selftransmissible conjugative plasmid by class 1 integron.
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Purpose: To observe the curative effect of acupuncture on female climacteric syndrome.Methods: Guanyuan (CV 4), Zhongji (CV 3), Zigong (Ex-CA 1), and Sanyinjiao (SP 6) were selected as main acupoints to treat 30 cases of female climacteric syndrome according to TCM principle of aiming mainly at the kidney in the treatment of this disease. Results: The total effective rate from acupuncture treatment of this disease was 90%. It was found in the patients that serum endocrine hormones changed significantly after acupuncture as compared with before it (P＜0.05). Conclusion: It is preliminarily considered that acupuncture has a comprehensive regulating effect on neuroendocrine system and can restore the dysfunctional vegetative nervous and endocrine systems to a stable state,removing or reliving various clinical symptoms in women's climacteric.
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Purpose:To determine the effect of serum expression VEGF in TACE of hepatocellular carcinoma. Methods:We examined tumor blood vessels of 30 patients with HCC by angiography and measured serum VEGF concentrations by ELISA.Results:We found serum VEGF concentrations in hypervascular patients were higher than in hypovascular patients (8.80?3.23 ng/ml vs 5.70?2.68 ng/ml, P