Objective To summarize the occurrence mechanism of backside wear, the method of evaluating backside surface damage, the relationship between backside wear and osteolysis in acetabulum, and the approach to reduce backside wear in total hip arthroplasty with modular acetabulum prosthesis. Methods The recent articles about the backside wear in acetabular liners were extensively reviewed. Results Backside wear in acetabular liners is connected with micromotion between the liner and the shell, rough interface, thickness of the liner, and impingement. The methods to evaluate backside wear damage are only proceeded in revised acetabular liners. Backside wear can generate polyethylene particles that is likely related to the process of osteolysis in acetabulum through the screw holes of metallic shell. To reduce backside wear between the liner and the shell, measures such as improved locking mechanisms, smooth inner metallic shell, maximized shell liner conformity, improving the quality of polyethylene, and reducing impingement can be taken. Conclusion There is no method of evaluating the backside wear in vivo. The relationship between backside wear and osteolysis in acetabulum as well as aseptic loosening of acetabulum prosthesis is controversial.
Objective To systematically assess the therapeutic effect of rivaroxaban and enoxaparin on preventing deep venous thrombosis after major orthopedic operation. Methods Such databases as MEDLINE, EMbase, The Cochrane Library (Issue 3, 2009), Current Controlled Trials, The National Research Register, CBM, and CNKI were searched from their establishment to December 2009 in whatever language. Related journals were handsearched as well. Randomized controlled trials (RCTs) of comparing therapeutic effects of rivaroxaban and enoxaparin on preventing deep venous thrombosis after major orthopedic operation were included. Data were extracted and their quality was evaluated, and meta-analyses were conducted by using RevMan 5.0.25 software. Results Seven RCTs with 15 458 patients were included. The results of meta-analyses showed that compared with enoxaparin, rivaroxaban reduced the end risk of the primary efficacy to 60% (RR=0.40, 95%CI 0.28 to 0.57, Plt;0.000 01) and reduced the end risk of the main secondary efficacy to 71% (RR=0.29, 95%CI 0.15 to 0.56, Plt;0.000 01), and the end risk of other efficacy to 56% (RR=0.44, 95%CI 0.29 to 0.66, Plt;0.000 01). During the treatment, rivaroxaban and enoxaparin displayed similarity in terms of the incidence of serious bleeding events (RR=1.16, 95%CI 0.68 to 1.999, P=0.59) and the secondary safety endpoint. Conclusion Rivaroxaban is effective in preventing deep venous thrombosis after major orthopedic operation and can significantly reduce the risk of postoperative deep vein thrombosis.
Brain computer interface is a control system between brain and outside devices by transforming electroencephalogram (EEG) signal. The brain computer interface system does not depend on the normal output pathways, such as peripheral nerve and muscle tissue, so it can provide a new way of the communication control for paralysis or nerve muscle damaged disabled persons. Steady state visual evoked potential (SSVEP) is one of non-invasive EEG signals, and it has been widely used in research in recent years. SSVEP is a kind of rhythmic brain activity simulated by continuous visual stimuli. SSVEP frequency is composed of a fixed visual stimulation frequency and its harmonic frequencies. The two-dimensional ensemble empirical mode decomposition (2D-EEMD) is an improved algorithm of the classical empirical mode decomposition (EMD) algorithm which extended the decomposition to two-dimensional direction. 2D-EEMD has been widely used in ocean hurricane, nuclear magnetic resonance imaging (MRI), Lena image and other related image processing fields. The present study shown in this paper initiatively applies 2D-EEMD to SSVEP. The decomposition, the 2-D picture of intrinsic mode function (IMF), can show the SSVEP frequency clearly. The SSVEP IMFs which had filtered noise and artifacts were mapped into the head picture to reflect the time changing trend of brain responding visual stimuli, and to reflect responding intension based on different brain regions. The results showed that the occipital region had the strongest response. Finally, this study used short-time Fourier transform (STFT) to detect SSVEP frequency of the 2D-EEMD reconstructed signal, and the accuracy rate increased by 16%.
ObjectiveTo compare the short-term effectiveness of femoral prosthesis with different neck-shaft angles for the reconstruction of proximal femoral anatomy after total hip arthroplasty (THA). MethodsBetween January 2012 and December 2013, 101 patients undergoing unilateral THA who accorded with selection criteria were selected for a retrospective study. The patients were divided into 2 groups:during THA, femoral prosthesis with 135° neck-shaft angle was used in 52 patients (group A) and femoral prosthesis with 127° neck-shaft angle was used in 49 patients (group B). There was no significant difference in gender, age, weight, body masss index, pathogeny, disease duration, preoperative neck-shaft angle, leg discrepancy, and preoperative Harris score between 2 groups (P>0.05). The postoperative Harris score was recorded to evaluate the effectiveness. And the femoral offset of the operated and contralateral sides, the change value of the femoral offset (xFO), the ratio of xFO to the offset of contralateral side (sdFO), the number of patients whose sdFO was more than 15% or less than -15% (outlier), the global offset, the height of femoral head rotation center, and leg discrepancy were measured at postoperation. ResultsOperative incision healed by first intension in 2 groups; no complication of infection, dislocation, or revision was found. All patients were followed up 12-32 months (mean, 23 months). The Harris score at last follow-up were significantly improved when compared with preoperative score in 2 groups (P＜0.05), but there was no signficant difference between 2 groups (t=1.267, P=0.832). The xFO and sdFO of group B were significantly larger than those of group A (P＜0.05); the number of outlier was 20 in group A and was 33 in group B, showing significant difference (P=0.005). The height of femoral head rotating center and global offset at 3 months after operation showed no signficant difference between 2 groups (P>0.05). And significant improvement in leg discrepancy was found at 3 months in 2 groups (P＜0.05), but there was no significant difference between 2 groups (t=0.403, P=0.689). ConclusionBoth of the two femoral prosthesis with different neck-shaft angles can restore the proximal femoral anatomy well and gain similar early effectiveness after THA. However, the Stryker Trident femoral prosthesis with 127° neck-shaft angle may have the tendency to enlarge the femoral offset.
ObjectiveTo evaluate the clinical therapeutic effect of biceps tendon tenotomy and fixation versus biceps tendon repair for shoulder superior labrum anterior posterior (SLAP) lesions with Meta-analysis. MethodsThe databases such as PubMed, EMbase, the Cochrane Library (Issue 3, 2014), CBM, VIP and CJFD (from the establishment time of databases to December 2014) were searched to collect all randomized controlled trials (RCT) on the clinical effectiveness of biceps tendon tenotomy and fixation versus biceps tendon repair for shoulder SLAP lesions. Two reviewers independently screened the literature according to the inclusive and exclusive criteria, extracted the data, and assessed the methodological quality of included studies. After the data extraction and methodological quality evaluation, meta-analysis was conducted with RevMan 5.0 software. ResultsThree RCT were included. Among the total 137 patients involved, Meta-analysis showed that, compared with the biceps tendon repair group, the biceps tenotomy group had superior amount in the UCLA score [WMD=3.43, 95%CI (2.29, 4.56), P<0.000 01], the shoulder pain [WMD=1.18, 95%CI (0.30, 2.05), P=0.009], function [WMD=0.96, 95%CI (0.51, 1.41), P<0.000 1] and satisfaction [WMD=1.16, 95%CI (0.31, 2.01), P=0.007] with significant differences. But there were no significant differences between the two groups in the shoulder flextion [WMD=0.10, 95%CI (-0.87, 1.06), P=0.84] and strength [WMD=0.13, 95%CI (-0.09, 0.35), P=0.25]. ConclusionBased on the current studies, the biceps tenotomy and fixation is superior to the biceps tendon repair in treating shoulder SLAP lesions. For the quality restrictions and possible publication bias of the included studies, more double blind, high quality RCT are required to further evaluate the effects.