Evaluation of thickness and appearance of anterior talofibular and calcaneofibular ligaments in normal versus abnormal ankles with MRI

Injuries to the lateral ligaments of the ankle are common in medical practice. The most commonly injured ligaments are the anterior talofibular (ATFL) and calcaneofibular (CFL) ligaments. When undertaking MRI evaluation of ankle injuries it is important to understand the normal dimensions, appearance and variations of these ligaments. Twenty-eight consecutive patients referred for MRI of the ankle underwent bilateral scanning. The thickness of normal and abnormal ATFL and CFL was determined. The mean thickness of the ATFL was 2.19 +/- 0.6 mm and the CFL measured 2.13 +/- 0.5 mm. One normal ankle had an extremely thin ATFL (0.8 mm) with an otherwise normal appearance, whereas two ankles had an ATFL with a high attachment, both of which were deemed to be normal variants. Nineteen per cent of normal CFLs were noted to consist of a lateral hypointense band with a medial isointense medial band. Two variations of normal ATFL, one normal variant CFL and a measurement of the normal thickness of the ATFL and CFL have been presented in this paper. These variations have not been described previously by other authors. It is envisaged that these findings will assist in the MRI assessment of the lateral ankle ligaments.

Deep venous thrombosis in postoperative vascular surgical patients: a frequent finding without prophylaxis

PURPOSE

The place of routine perioperative thromboprophylaxis for vascular surgical patients remains controversial, because the incidence of postoperative deep venous thrombosis (DVT) is said to be quite low. This study was designed to measure the incidence of lower limb DVT after vascular surgical procedures.

METHODS

All consenting, consecutive patients who came to a metropolitan veterans hospital for abdominal or lower-limb arterial surgery were studied. Clinical and operative data were recorded. Lower-limb color flow duplex scans were performed before and after surgery.

RESULTS

Fifty patients, age 75 +/- 1 (mean +/- SEM) years, were studied. Abdominal procedures were performed on 22 patients, and lower-limb procedures were performed on 28 patients. A postoperative DVT was noted in 14 patients (32%), 9 patients (41%) in the abdominal surgical group and 5 patients (18%) in the lower-limb group. Calf DVTs were four times more common than femoropopliteal DVTs.

CONCLUSION

The incidence of postoperative lower-limb DVTs in this cohort of vascular surgical patients was high. The small size of the study population precludes generalized recommendations, but the results indicate an urgent need for definitive investigation.

Polymorphisms of the renin-angiotensin system in patients with multifocal renal arterial fibromuscular dysplasia

Fibromuscular dysplasia (FMD) is an important cause of renal artery stenosis, particularly in young females. Polymorphisms of the renin-angiotensin (RA) system have been implicated in the pathogenesis of hypertension and atherosclerotic vascular disease, and may play a role in the development of FMD. Examination of polymorphisms by PCR for angiotensin-converting enzyme (ACE) I/D, angiotensin II type 1 receptor (AT1R) A1166C and angiotensinogen (AGT) M235T and T174M was undertaken in 43 patients with typical multifocal renal arterial FMD (MF-FMD) and in 89 controls. The age of MF-FMD patients at the time of diagnosis of hypertension did not differ (38.6 + 11.1 years vs 35.5 +/- 10.3 years, P = 0.12) from controls and the proportion (95% vs 86%, P = 0.14) of females was similar. Allele frequencies did not differ significantly between groups, except that MF-FMD patients had a significantly higher frequency of the ACE I allele than control subjects (0.62 vs 0.47, P = 0.026). Since the ACE I allele is associated with lower circulating ACE levels and possibly lower tissue levels of angiotensin II (Ang II), and since Ang II modulates vascular smooth muscle cell growth and synthetic activity, the I allele might predispose to defective remodelling of the arterial media, and thus to the development of MF-FMD. This contrasts with atherosclerotic renal artery stenosis, coronary stent restenosis and carotid intimal thickening, which are diseases affecting the arterial intima, and which are associated with increased frequency of the D allele.

Alpha-1-antitrypsin phenotypes in patients with renal arterial fibromuscular dysplasia

Fibromuscular dysplasia (FMD) is a significant cause of renal artery stenosis, especially in young females. A rare association between FMD and alpha 1-antitrypsin (alpha 1-AT) deficiency has been reported. We compared the alpha 1-AT phenotype distribution in 83 patients with renal arterial FMD with those published for Australian populations. alpha 1-AT phenotyping was performed by isoelectric focusing between pH 4.2 and pH 4.9 on polyacrylamide gels with PiM1M2, PiFM (non-deficiency alleles), PiMS and PiMZ (deficiency alleles) markers. Following phenotyping, alpha 1-AT genotyping was performed in 10 patients to confirm the presence of S and/or Z alleles. The phenotype distribution and allele frequencies were similar to those reported for normal subjects from two Australian populations (72 (86.7%) PiMM phenotype, one (1.2%) PiFM, seven (8.4%) PiMS, two (2.4%) PiMZ and one (1.2%) PiSZ), suggesting that alpha 1-AT deficiency is not a common aetiological factor in renal arterial FMD. However, despite FMD being three times less common in males than females, and carotid artery dissection being a rare occurrence, a male with PiMS deficiency phenotype presented with internal carotid artery dissection and had bilateral renal artery FMD. Further, a patient with PiSZ deficiency phenotype was one of two sisters with FMD and was more severely affected than her PiMM normal phenotype sibling. These two patients from the present series together with nine culled from the literature with alpha 1-AT deficiency phenotype and FMD suggest that the chance combination of alpha 1-AT deficiency and FMD may predispose to severe manifestations of FMD.

Increased severity of multifocal renal arterial fibromuscular dysplasia in smokers

Renal arterial fibromuscular dysplasia (FMD) is a significant cause of renovascular hypertension, especially in younger females. Tobacco constituents have been shown to stimulate proliferation and synthetic activity of cultured human vascular smooth muscle cells. We examined the relationship between smoking and severity of FMD in a group of 50 subjects with the multifocal form of renal arterial FMD. A detailed smoking history was obtained by interview, clinical data at diagnosis of FMD were obtained from medical records, and angiograms were reviewed. Clinical and angiographic features were compared between smokers and non-smokers. Twenty-four subjects were smokers. At the time of diagnosis of FMD, smokers were of younger mean age than non-smokers (38.7 years vs 48.9 years, P < 0.01), had a shorter median history of hypertension (1.5 years vs 8.5 years, P < 0.05), and had a higher prevalence of unilateral renal atrophy (67% vs 27%, P < 0.01). The distribution of age at diagnosis of FMD was unimodal in non-smokers and bimodal, with a discrete group of younger subjects, in smokers. We conclude that cigarette smoking is associated with an earlier onset and increased severity of disease in a susceptible subgroup of patients predisposed to multifocal renal arterial FMD.

Longitudinal tibial stress fractures

The tibia is a fairly common site for stress fractures of both the fatigue and insufficiency types. The majority are transverse or, less frequently, oblique. The present report outlines four cases of vertical stress fractures, an orientation that is very uncommon and leads to bone scan findings which can be misleading.

Cerebral torulosis: clinical features and correlation with computed tomography

Cryptococcus neoformans (Torula histolytica) is an uncommon cause of infection in the central nervous system. We review 15 cases from all over Queensland which have presented in the last 6 years. Computed tomography (CT) studies were abnormal in 73.5%, with mass lesions and hydrocephalus being the commonest findings. Notable findings were: the disproportionate severity of clinical signs and symptoms as compared with the CT findings, which often were either normal or demonstrated only small granulomas without significant mass effect, absence of enhancement in granulomas in two cases and observation of calcification during treatment in one patient.

Computed tomographic appearances and clinical features of prolactin-secreting pituitary adenomas in young male patients

Prolactin-secreting adenomas, the commonest of the pituitary tumours, are being recognised with increasing frequency in men. Their appearance and behaviour differ from those occurring in women, being typically larger and more aggressive. We describe the clinical features and radiological findings of three prolactinomas in young males and review the literature.