Search

The ligamentum capitis femoris ( LCF) has increased in clinical significance through the development of hip arthroscopy. The histological pathologies and molecular composition of the femoral attachment of the LCF and the degeneration caused by LCF disruption were investigated in the human hip joint. Twenty-four LCFs were retrieved at surgery for femoral neck fracture (age range: 63-87 years). In the 'intact' (i.e., intact throughout its length, n = 12) group, the attachment consisted of rich fibrocartilage. Fibrocartilage cells were present in the midsubstance. In contrast, the construction of the attachment in the 'disrupted' (i.e., ligament no longer attached to the femoral head, n = 12) group had disappeared. The attachment in the disrupted group was not labeled for type II collagen or aggrecan, while that in the intact group was labeled for types I, II and III collagen, chondroitin 4-sulfate, chondroitin 6-sulfate, aggrecan, and versican. The percentage of single-stranded DNA-positive chondrocytes was significantly higher in the disrupted group than in the intact group. We conclude that the femoral attachment of the LCF has a characteristic fibrocartilaginous structure that is likely to adjust to the mechanical load, and suggest that its degeneration is advanced by disruption and should be regarded as a clinical pathology. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article "The heamophilic ankle," by E. C. Rodriguez-Merchan.

Proximal patellar tendinopathy occurs as an overuse injury in sport and is also characteristic of ankylosing spondylitis patients. It particularly affects the posteromedial part of the patellar tendon enthesis, although the reason for this is unclear. We investigated whether there are regional differences in the trabecular architecture of the patella or in the histology of the patellar tendon enthesis that could suggest unequal force transmission from bone to tendon. Trabecular architecture was analysed from X-rays taken with a Faxitron radiography system of the patellae of dissecting room cadavers and in magnetic resonance images of the knees of living volunteers. Structural and fractal analyses were performed on the Faxitron digital images using MatLab software. Regional differences at the enthesis in the thickness of the uncalcified fibrocartilage and the subchondral plate were evaluated histologically in cadaveric material. The radiological studies showed that the quantity of bone and the apparent trabecular thickness in the patella were greatest medially, and that in the lateral part of the patella there were fewer trabeculae which were orientated either antero-posteriorly or superiorly inferiorly. The histological study showed that the uncalcified fibrocartilage was most prominent medially and that the subchondral plate was thinner laterally. Overall, the results indicate that mechanical stress at the proximal patellar tendon enthesis is asymmetrically distributed and greater on the medial than on the lateral side. Thus, we suggest that the functional anatomy of the knee is closely related to regional variations in force transmission, which in turn relates to the posteromedial site of pathology in proximal patellar tendinopathy. [ABSTRACT FROM AUTHOR]

Abstract The peroneal (fibularis) tendons are held in place within the malleolar groove by the superior peroneal retinaculum. If this is torn, the tendons can subluxate or dislocate. Understanding the anatomy of the region is important for treating these injuries when it becomes necessary to reconstruct the malleolar groove surgically. Serial transverse sections of the groove were cut from 10 dissecting room cadavers after routine histology processing. The structure of the malleolar groove differed significantly in its proximal and distal parts. Distally, the bone is convex and the shape of the groove is determined by a thick periosteal cushion of fibrocartilage that covers the bone surface. Proximally, the groove shape is determined by the bone itself, and the periosteum is thin and fibrous. The restriction of a periosteal fibrocartilage to the distal end suggests that it serves to adapt the shape of the malleolar groove to that of the tendons within it and thus promotes stress dissipation. Paradoxically, however, it increases the risk of damage to subluxated tendons, because these can be sliced longitudinally by a sharp ridge created from periosteal fibrocartilage when the retinaculum is torn. Our results suggest that if bone-block surgical procedures are used to reconstruct the malleolar groove, they are best restricted to its proximal part. [ABSTRACT FROM AUTHOR]

1. To develop and characterize a new animal model of hypertension and hyperlipidaemia, we cross-bred spontaneously hypertensive rats (SHR) with spontaneously hyperlipidaemic rats (HLR). 2. A new strain of spontaneously hypertensive hyperlipidaemic rats (SHHR) was established at generation 10 through selective mating of brothers and sisters (systolic blood pressure > 150 mmHg, plasma cholesterol > 150 mg/dL). Cross-bred Wistar-Kyoto (WKY) rats and Sprague-Dawley (SD) rats (SDWKY rats) were used as a control. 3. Adrenaline and noradrenaline levels in the plasma and adrenal medulla of male SHHR were significantly higher than those of male SDWKY rats. The tyrosine hydroxylase activity in the adrenal medulla of male SHHR was significantly higher than that of male SDWKY rats. Low-density lipoprotein expression was found in the plasma of male and female SHHR and HLR. Cholesterol 7alpha-hydroxylase mRNA expression in the liver of male SHHR was lower than that of male SDWKY rats. Endothelium lesions and lipid deposition under the endothelium were observed in the aorta of 24-month-old SHHR, especially female SHHR, but not in age-matched HLR and SDWKY rats. 4. The hypertension of this new animal model of hypertension and hyperlipidaemia may be related to increased catecholamine activity and the hyperlipidaemia may be related to changes in the expression of cholesterol 7alpha-hydroxylase mRNA and lipoprotein profiles. The SHHR may be valuable in the study of mechanisms of atherosclerosis and the evaluation of anti-atherosclerosis drugs as a new strain of cardiovascular disease.

Aims: To examine the effect of ticlopidine administration on the activities CYP2C19 and CYP3 A in vivo using omeprazole as a model substrate., Methods: A single dose of 40 mg omeprazole was administered orally with or without ticlopidine (300 mg daily for 6 days) to six Japanese extensive metabolisers with respect to CYP2C19. Blood samples were taken for the measurement of plasma concentrations of omeprazole, 5-hydroxyomeprazole and omeprazole sulphone., Results: Ticlopidine administration increased omeprazole Cmax (1978+/-859/ 3442+/-569 (control phase/ticlopidine phase, nm )) and decreased the oral clearance of omeprazole (CL/F; 25.70+/-16. 17/10.76+/-1.16 (control phase/ticlopidine phase, l h-1 )) significantly. The 5-hydroxyomeprazole to omeprazole AUC ratio (0. 817+/-0.448/0.236+/-0.053 (control phase/ticlopidine phase)) and the 5-hydroxyomeprazole to omeprazole sulphone AUC ratio (1.114+/-0. 782/0.256+/-0.051 (control phase/ticlopidine phase)) were decreased significantly after ticlopidine administration. The decrease in omeprazole CL/F and the 5-hydroxyomeprazole to omeprazole AUC ratio correlated significantly with their respective absolute values when the drug was given alone. The decrease in CL/F following ticlopidine administration correlated with that in the 5-hydroxyomeprazole to omeprazole AUC ratio., Conclusions: These findings suggest that ticlopidine inhibited the in vivo activity of CYP2C19, but not, or to a lesser extent CYP3 A4, and that the magnitude of inhibition by ticlopidine is related to the in vivo activity of CYP2C19 before inhibition.