The current findings substantiate the use of three-point fixation as the treatment of choice for C1-C2 instability. [l: atlantoaxial fixation, biomechanics, cervical spine, instability, spinal instrumentation, transarticular screws]
In comparison with Ringer's acetate, Hemospan mildly elevates hepatic enzymes and lipase and is associated with less hypotension and more bradycardic events. The absence of a high frequency of serious adverse events suggests that further clinical trials should be undertaken.
We performed this investigation to determine the possible migration starting immediately after surgery and the effect of different weightbearing regimens on the migration pattern of an uncemented hip stem (CLS). Stem migration was determined with radiostereometry analysis with baseline when the patients still were anesthetized. Subsequent examinations were done up to 1 year. Twenty-nine patients (mean age, 55 years; range, 26-63 years) were randomized to either unrestricted weightbearing combined with intensive physiotherapy from the first day after surgery or to partial weightbearing and a conservative training regimen for the first 3 months after surgery. At 1 week, subsidence was -0.03 mm in the unrestricted weightbearing group and 0.01 mm in the partial weightbearing group. At 1 year, subsidence was 1.01 mm in the unrestricted weightbearing group and 0.51 mm in the partial weightbearing group. One patient in the unrestricted weightbearing group had revision surgery because of aseptic loosening at 1.5 years after surgery. The CLS stem did not have any migration from the end the surgery until 1 week, but there was small migration from 1 week to 3 months after which the stem remained stable. The degree of early weightbearing did not affect the migration pattern.
With chicken used as a model species, we used QTL analysis to examine the genetic contribution to bone traits. We report the identification of four QTLs for femoral traits: one for bone strength, one for endosteal circumference, and two affecting mineral density of noncortical bone.Introduction: BMD is a highly heritable phenotype, governed by elements at numerous loci. In studies examining the genetic contribution to bone traits, many loci have been identified in humans and in other species. The goal of this study was to identify quantitative trait loci (QTLs) controlling BMD and bone strength in an intercross between wildtype and domestic chickens. Materials and Methods: A set of 164 markers, covering 30 chromosomes (chr.), were used to genotype 337 F 2 -individuals from an intercross of domesticated white Leghorn and wildtype red junglefowl chicken. DXA and pQCT were used to measure BMD and bone structure. Three-point bending tests and torsional strength tests were performed to determine the biomechanical strength of the bone. QTLs were mapped using forward selection for loci with significant marginal effects. Results: Four QTLs for femoral bone traits were identified in QTL analysis with body weight included as a covariate. A QTL on chr. 1 affected female noncortical BMD (LOD 4.6) and is syntenic to human 12q21-12q23. Also located on chr. 1, a locus with synteny to human 12q13-14 affected endosteal circumference (LOD 4.6). On chr. 2, a QTL corresponding to human 5p13-p15, 7p12, 18q12, 18q21, and 9q22-9q31 affected BMD in females; noncortical (LOD 4.0) and metaphyseal (LOD 7.0) BMD by pQCT and BMD by DXA (LOD 5.9). A QTL located on chr. 20 (LOD 5.2) affected bone biomechanical strength and had sex-dependent effects. In addition to the significant QTLs, 10 further loci with suggestive linkage to bone traits were identified. Conclusions: Four QTLs were identified: two for noncortical BMD, one for endosteal circumference, and one affecting bone biomechanical strength. The future identification of genes responsible for these QTLs will increase the understanding of vertebrate skeletal biology.
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