Varus derotation osteotomy for the treatment of hip subluxation and dislocation in cerebral palsy: statistical analysis in 73 hips.

The purpose of this study is to review the results of varus osteotomy in patients with cerebral palsy and to determine factors that influence the rates of residual hip displacement. A retrospective chart review of 65 patients who underwent 79 varus osteotomies was performed. Preoperative, postoperative and follow-up radiographs were analyzed for routine radiographic measurements, pelvic obliquity, osteonecrosis (avascular necrosis), joint incongruity or degenerative joint disease. The average follow-up was 5.2 years (range, 1.1-18.4 years). At follow-up, 3 hips were dislocated, 19 were subluxated and 57 were stable (72%). Age at surgery and the degree of preoperative hip displacement had significant effects on outcome. The average age at surgery for initially subluxated hips, which were located at follow-up, was 7.2 years. This was significantly younger (P = 0.008) than initially subluxated hips, which were displaced (10 years of age). Subluxated hips at surgery were also more likely to be located at follow-up than dislocated hips.

Effect of surgery on the nontreated hip in severe cerebral palsy.

We studied the fate of the nonoperated hip in 35 patients with cerebral palsy who underwent surgical stabilization for unilateral hip subluxation (24 patients) or dislocation (11 patients). Review of medical records and radiographs was performed and analysis was accomplished on the effect of preoperative and radiographic variables on the radiographic outcome of the nonoperated hip. The average age at surgery was 5.5 years and at follow-up was 9.7 years, with an average follow-up of 4.2 years. Before subsequent surgery (in 15 nonoperated hips) or at follow-up, 10 of the nonoperated hips were dislocated and 16 hips were subluxated. Hips were stable and less likely to have surgery if they had a lower initial migration index and higher center edge angles. We conclude that there are few indications for unilateral hip surgery in patients with diplegia or quadriplegia undergoing initial hip stabilization surgery, especially if any degree of dysplasia is present.

Joint effects of an aldosterone synthase (CYP11B2) gene polymorphism and classic risk factors on risk of myocardial infarction.

BACKGROUND: The -344C allele of a 2-allele (C or T) polymorphism in the promoter of the gene encoding aldosterone synthase (CYP11B2) is associated with increased left ventricular size and mass and with decreased baroreflex sensitivity, known risk factors for morbidity and mortality associated with myocardial infarction (MI). We hypothesized that this polymorphism was a risk factor for MI. METHODS AND RESULTS: We used a nested case-control design to investigate the relationships between this polymorphism and the risk of nonfatal MI in 141 cases and 270 matched controls from the Helsinki Heart Study, a coronary primary prevention trial in dyslipidemic, middle-aged men. There was a nonsignificant trend of increasing risk of MI with number of copies of the -344C allele. However, this allele was associated in a gene dosage-dependent manner with markedly increased MI risk conferred by classic risk factors. Whereas smoking conferred a relative risk of MI of 2.50 (P=0.0001) compared with nonsmokers in the entire study population, the relative risk increased to 4.67 in -344CC homozygous smokers (relative to nonsmokers with the same genotype, P=0.003) and decreased to 1.09 in -344TT homozygotes relative to nonsmokers with this genotype. Similar joint effects were noted with genotype and decreased HDL cholesterol level as combined risk factors. CONCLUSIONS: Smoking and dyslipidemia are more potent risk factors for nonfatal MI in males who have the -344C allele of CYP11B2.

"Bone bruises" of the knee: a review.

Magnetic resonance (MR) imaging is often used to assess the location and degree of ligamentous or cartilage damage in the knee following acute traumatic injury. Occasionally, these studies will also document abnormal signal within the adjacent subchondral bone. These "bone bruises" are considered incidental findings by some, while others suggest possible clinical significance. The purpose of this paper is to review the literature and consolidate current thinking on the radiographic characteristics, classification, histopathology and natural history of bone bruises.

Ureteral compression and obstruction by spine rods.

We present a case of extrinsic compression of a ureter by spinal fixation hardware and adjacent fibrosis that resulted in progressive obstructive hydronephrosis, loss of renal function, and, ultimately, nephrectomy.

Variation in placental type 2 11beta-hydroxysteroid dehydrogenase activity is not related to birth weight or placental weight.

It has been suggested that the association between the development of hypertension and a combination of low birth weight and high placental weight can be explained by variations in expression of NAD+-dependent 11beta-hydroxysteroid dehydrogenase (11-HSD2 or 11-HSD K) in the placenta. Enzymatic activity and mRNA levels of 11-HSD2 were measured in 111 human placentas taken from normal births. There were no correlations between either 11-HSD2 activity or mRNA levels and either fetal or placental weight. These studies suggest that variations in placental 11-HSD activity do not influence fetal or placental weight in humans.

Molecular analysis of 11 beta-hydroxysteroid dehydrogenase and its role in the syndrome of apparent mineralocorticoid excess.

The syndrome of apparent mineralocorticoid excess (AME) is an inherited form of hypertension in which 11 beta-hydroxysteroid dehydrogenase (11-HSD) is defective. This enzyme converts cortisol to its inactive metabolite, cortisone. The deficiency allows mineralocorticoid receptors to be occupied by cortisol, because these receptors themselves have similar affinities for cortisol and aldosterone. There are two isozymes of 11-HSD, a liver (L) or type 1 isozyme with a relatively low affinity for steroids, and a kidney (K) or type 2 isozyme with high steroid affinity. Mutations in the gene for the kidney isozyme of 11-HSD have been detected in all kindreds with AME. We expressed enzymes carrying all known missense mutations in cultured cells and determined their activity. For each patient with AME, we compared the enzymatic activity predicted by the genotype with the ratio of cortisol to cortisone metabolites in the urine, (THF + aTHF)/THE. These were strongly correlated, suggesting that the biochemical phenotype of AME is largely determined by genotype. The K isozyme of 11-HSD is also expressed in high levels in the placenta, where its function is unclear. AME patients often have low birth weight. By analogy with AME, low placental 11-HSD K activity in humans might be a risk factor for low birth weight and subsequent hypertension. However, we found that there was no significant correlation between 11-HSD activity, mRNA levels, and either fetal or placental weight.

11 beta-Hydroxysteroid dehydrogenase and its role in the syndrome of apparent mineralocorticoid excess.

Aldosterone, the most important mineralocorticoid, regulates electrolyte excretion and intravascular volume mainly through its effects on renal distal tubules and cortical collecting ducts, where it acts to increase sodium resorption from and potassium excretion into the urine. Excess secretion of aldosterone or other mineralocorticoids, or abnormal sensitivity to mineralocorticoids, may results in hypokalemia, suppressed plasma renin activity, and hypertension. The syndrome of apparent mineralocorticoid excess (AME) is an inherited form of hypertension in which 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD) is defective. This enzyme converts cortisol to its inactive metabolite, cortisone. Because mineralocorticoid receptors themselves have similar affinities for cortisol and aldosterone, it is hypothesized that the deficiency allows these receptors to be occupied by cortisol, which normally circulates at levels far higher than those of aldosterone. We cloned cDNA and genes encoding two isozymes of 11 beta-HSD. The liver (L) or type 1 isozyme has relatively low affinity for steroids, is expressed at high levels in the liver but poorly in the kidney, and is not defective in AME. The kidney (K) or type 2 isozyme has high steroid affinity and is expressed at high levels in the kidney and placenta. Mutations in the gene for the latter isozyme have been detected in all kindreds with AME. Moreover, the in vitro enzymatic activity conferred by each mutation is strongly correlated with the ratio of cortisol to cortisone metabolites in the urine [tetrahydrocortisone (THF) +allo-THF]/THE. This suggests that the biochemical phenotype of AME is largely determined by genotype.

The resistance of the Wistar/Furth rat strain to steroid hypertension.

We have previously reported that the Wistar/Furth (W/Fu) rat strain is resistant to mineralocorticoid hypertension. In the current study, we have examined renal mRNA levels for mineralocorticoid receptor (MR), glucocorticoid receptor (GR), renin and Na+, K(+)-ATPase in response to treatment with mineralocorticoids. Uninephrectomized male Wistar (WI) and W/Fu rats were treated with aldosterone or deoxycorticosterone acetate (DOCA) and were given 1% NaCl to drink. Rats were sacrificed after 1, 3 or 7 days of treatment. Renal MR and ATPase mRNA levels were significantly reduced in aldosterone and DOCA-treated WI rats (e.g. MR was 30% on day 3 and ATPase was 50% of control on day 7 of aldosterone treatment). Unexpectedly, GR mRNA levels paralleled the changes in MR. In W/Fu rats the level of message was either unchanged or only moderately altered by this treatment. In vivo administration of the MR antagonist RU28318 or the GR antagonist RU38486 to WI rats for 4 days reduced renal mRNA levels for both subunits of ATPase. In the W/Fu rat, this treatment resulted in no change in the alpha subunit and an increase in the beta subunit of ATPase. In preliminary studies, we have determined that the W/Fu rat is also resistant to dexamethasone-induced hypertension. These studies suggest that altered MR- and GR-mediated mechanisms may contribute to the resistance of the W/Fu rat strain to steroid-induced hypertension.

Acute and chronic tears of the anterior cruciate ligament: differential features at MR imaging.

To evaluate the differential features of acute and chronic tears of the anterior cruciate ligament at magnetic resonance (MR) imaging, the authors performed a retrospective evaluation of findings in 81 MR examinations correlated with results at arthroscopy. Intact anterior cruciate ligaments (ACLs) were present in 29 patients; acute complete ACL tears, in 22; and chronic complete ACL tears, in 30. Acute tears were accurately distinguished from intact ligaments and were characterized by the presence of edema. Chronic tears had a more variable appearance: Nine (30%) were depicted at MR as intact bands with low signal intensity that bridged the expected origin and insertion of the ACL. This appearance is likely due to the presence of bridging fibrous scars within the intercondylar notch. Five of these nine cases were correctly characterized as chronically torn because of the presence of focal angulation. In four of these nine cases the scarred fragments produced a relatively straight band that mimicked an intact ligament. Although chronic and acute ACL tears usually have distinct findings at MR, a chronic tear will occasionally be difficult to distinguish from an intact ligament.