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ABSTRACT: Several controversies exist regarding the superiority of double-bundle (DB) posterior cruciate ligament (PCL) reconstruction versus single-bundle (SB) reconstruction, although DB reconstruction has been shown to restore the intact knee kinematics more closely than SB reconstruction.
Double-bundle PCL reconstruction will present better results than SB reconstruction in postoperative outcomes.
Randomized controlled trial; Level of evidence, 2.
The authors prospectively analyzed 25 cases of SB reconstruction and 28 cases of DB reconstruction using Achilles tendon allograft with a minimum 2-year follow-up. They compared preoperative and postoperative range of motion, posterior stability by posterior stress radiography, Tegner activity score, Lysholm score, and International Knee Documentation Committee (IKDC) subjective knee evaluation form and knee examination form between the 2 groups.
There was no difference in range of motion, Tegner activity score, Lysholm score, and IKDC subjective knee evaluation form between the 2 groups at last follow-up. The side-to-side difference in posterior translation significantly improved in both groups. There was no preoperative difference in posterior instability between the groups but a significant difference at last follow-up. On the IKDC knee examination form, the DB reconstruction group presented better results in grade distribution.
The DB reconstruction for PCL ruptures using the Achilles allograft showed better results in posterior stability and IKDC knee examination form than the SB reconstruction did. Although the difference of 1.4 mm in posterior stability was statistically significant, it is unclear that DB reconstruction is definitely superior to SB reconstruction clinically and functionally because there was no difference in the subjective scores.
The American journal of sports medicine 11/2010; 39(3):474-80. · 3.61 Impact Factor
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ABSTRACT: Median linear regression modeling is a natural approach for analyzing censored survival or failure time data. A median linear model lends itself to a simple interpretation that is particularly suitable for making direct predictions of survival or failure times. We propose a new, unique, and efficient algorithm for tree-structured median regression modeling that combines the merits of both a median regression model and a tree-structured model. We propose and discuss loss functions for constructing this tree-structured median model and investigate their effects on the determination of tree size. We also propose a split covariate selection algorithm by using residual analysis (RA) rather than loss function reduction. The RA approach allows for the selection of the correct split covariate fairly well, regardless of the distribution of covariates. The loss function with the transformed data performs well in comparison to that with raw or uncensored data in determining the right tree size. Unlike other survival trees, the proposed median regression tree is useful in directly predicting survival or failure times for partitioned homogeneous patient groups as well as in revealing and interpreting complex covariate structures. Furthermore, a median regression tree can be easily generalized to a quantile regression tree with a user-chosen quantile between 0 and 1. We have demonstrated the proposed method with two real data sets and have compared the results with existing regression trees.
IEEE Transactions on Systems Man and Cybernetics - Part A Systems and Humans 06/2008; · 2.12 Impact Factor
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ABSTRACT: Foam cell formation from monocyte-derived macrophages is a hallmark of atherosclerotic lesions. Aspects of this process can be recapitulated in vitro by exposing M-CSF-induced or platelet factor 4 (CXCL4)-induced macrophages to oxidized (ox) or minimally modified (mm) low density lipoprotein (LDL). We measured gene expression in peripheral blood mononuclear cells, monocytes, and macrophages treated with CXCL1 (GRO-alpha) or CCL2 (MCP-1), as well as foam cells induced by native LDL, mmLDL, or oxLDL using 22 Affymetrix gene chips. Using an advanced Bayesian error-pooling approach and a heterogeneous error model with a false discovery rate <0.05, we found 5,303 of 22,215 probe sets to be significantly regulated in at least one of the conditions. Among a subset of 917 candidate genes that were preselected for their known biological functions in macrophage foam-cell differentiation, we found that 290 genes met the above statistical criteria for significant differential expression patterns. While many expected genes were found to be upregulated by LDL and oxLDL, very few were induced by mmLDL. We also found induction of unexpected genes, most strikingly MHC-II and other dendritic cell markers such as CD11c. The gene expression patterns in response to oxLDL were similar in M-CSF-induced and CXCL4-induced macrophages. Our findings suggest that LDL and oxLDL, but not mmLDL, induce a dendritic cell-like phenotype in macrophages, suggesting that these cells may be able to present antigens and support an immune response.
Physiological Genomics 05/2007; 29(2):149-60. · 2.73 Impact Factor
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ABSTRACT: Although the sixth edition of the American Joint Committee on Cancer (AJCC) staging system for extrahepatic bile duct carcinoma was updated, the system has a problem on T classification due to its ambiguous definition of T1 as "tumor confined to bile duct histologically" and T2 as "tumor invading beyond the bile duct."
The authors considered the outermost part of the muscle layer or fibrous tissue as within the extrahepatic bile duct and considered the area starting from large clusters of adipose tissue as beyond the extrahepatic bile duct. After designing a precise definition of the extrahepatic bile duct wall, they analyzed the new AJCC staging system in 222 patients with of extrahepatic bile duct carcinomas. Then, other clinicopathologic variables for prognosis were evaluated using univariate and multivariate analyses.
The 5-year survival rates for patients with tumors that were classified as T1, T2, T3, and T4 were 53.1%, 29.7%, 24.9%, and 0%, respectively. There was a significant difference in survival between patients with T1 tumors and T2 tumors (P < 0.05), but not between patients with T2 tumors and T3 tumors. Significant prognostic factors included depth of invasion (P < 0.005), lymph node metastasis (P < 0.005), and patient age (P < 0.05).
Based on a proposed histologic definition, depth of invasion was practical for evaluating the prognosis of patients with middle and upper extrahepatic bile duct carcinomas. Therefore, the authors recommended changing the current pT1 and pT2 classifications to more precise pathologic terminology.
Cancer 09/2005; 104(4):802-10. · 4.77 Impact Factor
