[Periostal interposition in epiphysiolysis, diagnosed by ultrasound]. / Periost-interposition ved epifysiolyse, diagnosticeret med ultralyd.

Musculoskeletal ultrasound is a rapidly expanding diagnostic field. High frequency transducers with high spacial resolution make it possible to demonstrate superficial soft tissue structures such as tendons, muscles, ligaments and even, under certain circumstances, fractures and periosteum. A case is presented where ultrasound clearly visualised periostal interposition in a distal tibial epiphysiolysis in an eight year-old boy, and some aspects of ultrasound in musculo-skeletal imaging are discussed.

Radiographic assessment of sagittal knee instability in weight bearing. A study on anterior cruciate-deficient knees.

In 16 patients with chronic, symptomatic anterior cruciate ligament-deficient knees, sagittal displacement was studied in the standing position using fluoroscopic control and a simple device to support the knee. In slight weight bearing all knees but one had normal femorotibial alignment in the lateral view. During full weight bearing sagittal displacements between 2 mm and 17 mm were recorded in 14 patients. The largest displacements were obtained at different angles of inclination of the leg and flexion of the knee joint and were independent of the point of support of the knee joint. The reproducibility of this new standing technique was within 2 mm. A high correlation with previous methods of radiographic measurements of sagittal laxity was found. By the use of the normal relationship between the tibial eminence and the femoral condyles it is possible to record and measure sagittal displacements on a single lateral radiograph of the standing knee joint.

Spinal gas collection demonstrated at CT.

In 234 consecutive CT examinations of the lumbar spine, gas collection was observed in 4 cases with disk herniation, and in 6 cases of disk protrusion. In 3 cases free gas was found in the epidural space, and one patient presented an intraspinal gas-filled "bleb". Gas collection in intervertebral disk spaces and facet joints was found in a total of 60 patients. The CT findings and surgical results were compared to determine whether gas collection contributes to clinical symptoms. In most cases the presence of gas was not clinically important, but in one patient it presented as a spinal mass, causing pain and radiculopathy.

Measurement of transcutaneous PO2, PCO2 and skin blood flow at different probe temperatures using mass spectrometry.

Transcutaneously measured partial pressures of oxygen and carbon dioxide (PtcO2, PtcCO2) approximate the corresponding arterial values at a probe temperature of 44 degrees C. The temperature-dependent increase of PtcO2 and PtcCO2 is caused by an increased skin perfusion, a decrease in the mean diffusion path, a change of skin metabolism, a decrease of tissue solubility of oxygen and carbon dioxide and a right shift of the oxygen and carbon dioxide binding curves of blood. Seven healthy volunteer test subjects participated in the study. A transcutaneous probe connected to a mass spectrometer was placed on the earlobe of the test subject. Four measurements of the transcutaneous PO2, PCO2 and skin blood flow (from the washout kinetics of argon) were determined on each test subject. The first measurement was made with a transcutaneous probe temperature of 37 degrees C. The probe temperature was then increased to 44 degrees C before the next determination. Finally, two determinations were made at 37 degrees C, separated by a time interval of 1 h. The PtcO2 and skin blood flow increased when the probe temperature increased from 37 degrees C to 44 degrees C. However, when the probe temperature was decreased again from 44 degrees C to 37 degrees C, the estimated skin blood flow returned to the initial value while the PtcO2 remained unchanged. It required a further 1 h before the PtcO2 returned to the initial value at 37 degrees C. The most likely explanation of the experimental results is that heating of the skin to 44 degrees C causes a reversible decrease in the skin metabolism.

Follow-up investigation of fresh lunate bone fracture.

In order to evaluate the clinical and radiological aspects of fresh lunate fractures, a follow-up investigation was carried out. In the past thirty-one years (1956-1986), seventeen patients were found to have fresh lunate fractures. Eleven of these cases were clinically and radiologically reexamined, with observation intervals ranging from 1.25 to 31.33 years. The authors found no radiologic evidence of lunatomalacia, osteonecrosis, or osteoarthrosis. Two cases of chip-fractures had not healed, but the bone structure was normal. Clinically, none of the patients presented with pain, muscular atrophy, or reduced power of grip. None of the patients had changed occupation as a result of the fracture.

Classification of fresh fractures of the lunate.

The X-rays of 17 patients with fresh fractures of the lunate bone have been reviewed. The fractures were classified according to their radiological appearances and according to the vascular anatomy of the lunate. A long term X-ray follow-up examination was performed.

Localized cortical bone sclerosis and intramedullar linear sclerosis in neurofibromatosis.

A case of localised cortical bone sclerosis of the left tibia and intramedullar linear sclerosis in the left femur, in association with neurofibromatosis in a 25-year-old female, is presented. The differential diagnostic problems in relation to bone tumours are emphasised.

Transcutaneous measurement of the oxygen partial pressure using argon to correct for the oxygen consumption of the probe.

The oxygen consumption of a transcutaneous probe creates an oxygen diffusion gradient between the skin capillaries and the probe, and this gradient causes the ratio between the oxygen partial pressure at the surface of the transcutaneous probe and the mean capillary pO2 to be less than 1. The ratio is usually increased towards unity by heating the skin to 43-45 degrees C, but this method introduces both practical and theoretical complications: the risk of skin burns and the increase in pO2 over the value in the blood at 37 degrees C. We present a new method to evaluate the ratio between the oxygen partial pressure at the surface of the transcutaneous probe and the mean capillary pO2. The method was used in measurements of the mean capillary pO2 in the skin of eight volunteers with a low-temperature probe (40 degrees C). The mean value of the ratio was 0.56 with a considerable variation from one person to another and from one skin location to another.