Osteochondral lesions of the talus: a revised classification.

Osteochondral lesions of the talus present a numerically small but therapeutically significant problem to the foot surgeon. The diagnosis and investigation of such lesions have been greatly enhanced by modern high resolution magnetic resonance imaging capabilities, which have provided far greater detail of the pathological anatomy. We have reviewed our experience in this area and suggest a revised classification for osteochondral lesions appropriate to the detail available on magnetic resonance imaging scans. The cause of osteochondral lesions is also discussed.

Comparison of the use of a foot pump with the use of low-molecular-weight heparin for the prevention of deep-vein thrombosis after total hip replacement. A prospective, randomized trial.

We conducted a prospective, randomized trial to compare the safety and effectiveness of the A-V Impulse System foot pump with that of low-molecular-weight heparin for reducing the prevalence of deep-vein thrombosis after total hip replacement. Of 290 patients who were to have a primary total hip replacement, 143 were randomized to receive enoxaparin (forty milligrams daily) for seven days after the operation and 147, to use the foot pump for seven days. The primary outcome measure was the prevalence of deep-vein thrombosis, as determined by venography on the sixth, seventh, or eighth postoperative day. Secondary outcome measures included transfusion requirements, intraoperative blood loss, postoperative drainage, blood-loss index, appearance of the site of the wound according to a subjective visual-analog scale, and swelling of the thigh. The patients' compliance with the regimen for use of the foot pump was monitored with an internal timing device, and their acceptance of the device was assessed with a questionnaire. Symptoms consistent with pulmonary embolism were investigated with ventilation-perfusion scanning. The patients were contacted later for detection of symptoms of venous thromboembolism that may have occurred during the first three months after discharge from the hospital. Venography was performed on 274 patients: 136 who used the foot pump and 138 who received enoxaparin. Deep-vein thrombosis was detected in twenty-four (18 per cent) of the patients who used the foot pump compared with eighteen patients (13 per cent) who received enoxaparin (95 per cent confidence interval for the difference in proportions, -3.9 to +13.0 per cent). Thrombosis in the calf was found in seven patients (5 per cent) in the former group compared with six patients (4 per cent) in the latter (95 per cent confidence interval for the difference, -4.2 to +5.8 per cent), and proximal thrombosis was observed in seventeen patients (13 per cent) in the former group compared with twelve patients (9 per cent) in the latter (95 per cent confidence interval for the difference, -3.5 to +11.1 per cent). None of these differences was significant. No patient in either group had major proximal deep-vein thrombosis; all proximal thrombi were isolated entities involving the femoral valve cusp and were of unknown importance. One patient who used the foot pump had a non-fatal pulmonary embolism. One patient who received enoxaparin had a symptomatic deep-vein thrombosis during hospitalization. Two patients (one from each group [0.7 per cent]) were readmitted to the hospital because of a symptomatic deep-vein thrombosis despite normal venographic findings at the time of discharge. There was no difference in the transfusion requirements or the intraoperative blood loss between the two groups. There were more soft-tissue side effects in the patients who received enoxaparin than in those who used the foot pump: there was more bruising of the thigh and oozing of the wound (p < 0.001 for each), postoperative drainage (578 compared with 492 milliliters; p = 0.014), and swelling of the thigh (twenty compared with ten millimeters; p = 0.03). Of 124 patients who used the foot pump and were asked about the acceptability of the device, fourteen (11 per cent) said that it was uncomfortable, twenty-one (17 per cent) reported sleep disturbance, and four (3 per cent) stated that they had stopped using the device. Conversely, ten (8 per cent) found it relaxing. We concluded that the foot pump is a suitable alternative to low-molecular-weight heparin for prophylaxis against thromboembolism after total hip replacement and that it produces fewer soft-tissue side effects. Tolerance of the device is a problem for some patients.

Perioperative low-molecular-weight heparin. Is it effective and safe.

In previous randomised clinical trials of thromboprophylaxis after total hip replacement, low-molecular-weight heparin has been given for an arbitrary 7 to 14 days. The risk factors are mainly perioperative and it is possible that a shorter course may be adequate. We assessed the safety and effectiveness of a three-day course. We assessed 156 primary THR patients after randomisation to either a control group or to receive enoxaparin at 12 hours preoperatively and 12 and 36 hours postoperatively. Thrombosis was diagnosed by routine venography. Haemorrhagic side-effects were assessed by measurement of blood loss, and soft-tissue side-effects by descriptive scores for wound discharge and bruising of the leg. The prevalence of calf thrombosis was 15.4% in the enoxaparin group and 32.1% in the control group (p = 0.01); the prevalence of proximal thrombosis was 15.4% and 17.9% respectively (not significant). There was no difference in haemorrhagic side-effects or wound discharge, but there was more bruising in the enoxaparin group.

Measurement of femoral vein blood flow during total hip replacement. Duplex ultrasound imaging with and without the use of a foot pump.

We examined ten femoral veins with duplex ultrasound during total hip replacement to demonstrate the operative manoeuvres which cause venous obstruction and to assess prophylactic measures which may overcome it. Exposure of the acetabulum by distraction of the femur with a hook was less likely to occlude flow than retraction with bone levers. Adequate exposure of the femoral shaft by adduction, flexion and either internal or external rotation caused cessation of flow in all cases. In four cases an A-V Impulse System foot pump was activated during periods of stasis. In each case it overcame the obstruction and produced peak velocities which were twice that of the resting state. In five cases, towards the end of the procedure, debris was seen travelling proximally through the femoral vein.

Computerized strain-gauge plethysmography in the diagnosis of symptomatic and asymptomatic venous thrombosis.

This study compares the results of a computerized strain-gauge plethysmograph with ascending lower limb venography in 94 patients with clinical deep venous thrombosis, and in 121 patients with asymptomatic legs being screened after total hip replacement. In the symptomatic patients, strain-gauge plethysmography had a sensitivity of 100%, an accuracy of 73%, a specificity of 64% and a negative predictive value of 100% for thrombosis above the popliteal confluence. In the screened patients, the figures were 38.1%, 55.4%, 60.0% and 81.1% respectively. Computerized strain-gauge plethysmography is a safe, non-invasive, reliable and portable method of excluding proximal thrombosis in a symptomatic patient. It avoids the need for urgent venography when anticoagulation therapy is reserved for those with proximal thrombosis. The device was not valuable as a screening tool after total hip replacement, since it had a low specificity and did not reliably detect the non-occlusive mural femoral thrombi which typically follow this procedure.

Case report: cervical Castleman's disease shown by CT and MRI.

Castleman's disease is a rare condition usually presenting as a localized mass of lymphoid tissue in the thorax. We report the CT and MRI appearances of a case of cervical Castleman's disease.

Impedance plethysmography and thrombo-embolic disease.

This study compares the results of impedance plethysmography with lower limb venography in 68 patients referred for investigation of clinical deep vein thrombosis, and with the results of ventilation/perfusion isotope scans in 125 patients with suspected pulmonary embolism. Impedance plethysmography had a sensitivity of 100% and a specificity of 61% for the detection of thromboses involving popliteal or more proximal veins (30 patients), but a sensitivity of 90% and a specificity of 68% in the detection of thrombosis at any level, because of a low sensitivity in the detection of isolated calf vein thrombosis (60% in 10 patients). It is a non-invasive, portable and low-cost technique and, in centres where anticoagulation is only given to patients with popliteal or more proximal thrombosis, venography may only be necessary if impedance plethysmography is positive. It may also be of value in the assessment of patients with suspected pulmonary embolic disease and an indeterminate ventilation/perfusion lung scan.

MRI of the cervical spine: rheumatoid arthritis compared with cervical spondylosis.

This study is a comparison of the cervical spine MR images from 26 patients with rheumatoid arthritis of the cervical spine with those from an age and sex matched group suffering from cervical spondylosis. Erosion of bone and major atlanto-axial subluxation were confined to rheumatoid arthritis. Soft tissue changes revealed by MRI included distortion of normal ligaments and bursae around the dens, particularly in rheumatoid arthritis. Abnormal masses of soft tissue were found in both groups, but those suggesting acute inflammation were much more frequent in rheumatoid arthritis than in cervical spondylosis. Neural compression was well demonstrated, and in rheumatoid arthritis was usually caused by bony structures whereas in cervical spondylosis it was usually due to disc material. It is concluded that MRI should be used as the first investigation to follow plain films in rheumatoid arthritis of the cervical spine. Bone and soft tissue changes are clearly shown, but interpretation of the images requires the recognition that some observed abnormalities may be due to coincidental cervical spondylosis.

The right aortic arch revisited.

The association between congenital cardiac defects and a right-sided aortic arch was assessed in 900 children undergoing cardiac angiography. Some of the associations observed differ from those reported in the established radiological literature. A right arch occurred in 15% of children with truncus arteriosus (up to 50% quoted in the literature), and in only 3% of those with tricuspid atresia (15% quoted in the literature). Anatomically corrected transposition of the great arteries was more strongly associated (18.2%) than has previously been suggested. These differences from previous series may, in part, be due to the improved survival of sick neonates allied with earlier diagnosis and better surgical management.

Pharmacokinetics of teicoplanin in subjects with varying degrees of renal function.

The pharmacokinetics of teicoplanin were studied in 20 subjects with varying degrees of renal function after administration of a single 200 mg intravenous dose. Pharmacokinetic parameters were calculated with a three compartment open model and by non-compartmental analysis. The elimination half-life increased as creatinine clearance decreased (rs = -0.87, P less than 0.001). The distribution volume was 1.0 (+/- 0.3) 1/kg of actual body weight and did not vary with changes in creatinine clearance. In normal subjects the main route of elimination was renal. The plasma clearance of teicoplanin correlated with creatinine clearance (rs = 0.91, P less than 0.001). At lower levels of creatinine clearance the variation in elimination half-life was such that we recommend individualization of the teicoplanin dosage following the measurement of the drug concentration in plasma.

Separation of skin reactive intestinal cancer antigen from the carcinoembryonic antigen of Gold.

Soluble fractions of human intestinal cancer and fetal intestinal cell membranes produced delayed hypersensitivity reactions in patients with intestinal cancer. These soluble fractions and perchloric acid extracts of intestinal cancer cells were fractionated by polacrylamide-gel electrophoresis. The Gold carcinoembryonic antigen was found in a region of the gels different from that of the skin reactive antigen.