Gunnar Schwarz Lausten

Microvascular obstruction in avascular necrosis Immunohistochemistry of 14 femoral heads

14 femoral heads with late stage avascular necrosis of different etiologies were histologically examined, with special attention to vascular structures. Decalcified slices were stained with hematoxylin-eosin, safranin-O, van Gieson stain, and Martius Scarlet Blue. Immunohistochemical techniques with antibodies against Factor VIII, and Ulex Europeus Lectin were used to visualize the endothelium of the blood vessels. 5 distinct zones of the necrotic femoral head could be identified. The necrotic zone contained areas with richly vascularized connective tissue. In the transitional zone, several areas with intravascular aggregations of newly formed and older fibrin clots were noticed, mainly on the venous side of the vascular system. Other small vessels were collapsed, with a few endothelial cells clumped together in the center of a concentric fibrous tissue. We suggest that obstruction to the venous outflow due to intravascular thrombosis as well as to perivascular fibrosis is important in the pathogenesis of non-traumatic avascular necrosis of the femoral head.

Core decompression for femoral head necrosis. Prospective study of 28 patients.

Totally, 28 consecutive patients with nontraumatic osteonecrosis of the femoral head were included in a prospective study of the clinical and radiographic results of core decompression. One patient (one hip) was lost to follow-up. Preoperatively, the stage according to Ficat (1985) was assessed by plain radiography and scintimetry. After 1-2 years, hip replacement had been performed in 4/11 Stage 1, 7/11 Stage 2, and 4/7 Stage 3 hips, while the remaining 12 hips were judged satisfactory. We conclude that the outcome of core decompression for nontraumatic necrosis of the femoral head is unpredictable.

Necrosis of the femoral head after renal transplantation.

The cumulated risk of developing necrosis of the femoral head following renal transplantation was 42/374 in patients treated with steroids and azathioprine, and 4/124 in patients treated with cyclosporine-A and a reduced dose of steroids. 29 of the osteonecrosis cases were bilateral, with the time lapse between the two sides rarely exceeding 6 months. The reduction in the rate of osteonecrosis paralleled a reduction in the number of rejection episodes during the first month after transplantation and in the cumulated dose of steroids 1 month and 1 year after transplantation. We concluded that the risk of femoral head necrosis following renal transplantation is reduced by using cyclosporin-A for immunosuppression, which caused less rejection episodes and consequently a reduction in steroid medication.

Real-time sonography of anterior translation of the shoulder : an anterior approach

Abstract Objective: In this prospective study, we established and evaluated an ultrasound technique to demonstrate anterior passive translation of the shoulder, using a new anterior approach. Methods: A preliminary in vitro study was performed, with anterior ultrasound scanning of a skeleton in a waterbath. Forty shoulders in twenty normal subjects were then examined with a 3.5 MHz linear transducer, using the same anterior approach. The anterior range of motion (ROM) was measured during passive anterior translation. Results: Anatomical landmarks were identified anteriorly on the humerus and the scapula, to define a scanning plane, in which ROM was measured to 1.8 ± 0.1 mm (mean ± S.E.M.) (range 0.4–4.1 mm). The difference in ROM between the two shoulders of each subject (Δ ROM) was calculated: 0.7 ± 0.1 mm (range 0.1–1.9 mm). Conclusion: The anterior translation of the shoulder can be assessed objectively, non-invasively and rapidly by ultrasonography. We found ROM to be less than 4 mm, and A ROM to be less than 2 mm. The interobserver variability of the method remains to be investigated, as is its usefulness in the diagnosis of chronic anterior shoulder instability.

Blood perfusion uneven in femoral head osteonecrosis: Doppler flowmetry and intraosseous pressure in 12 cases

We measured the microvascular regional perfusion in 12 hips with non-traumatic osteonecrosis of the femoral head, using laser Doppler flowmetry (LDF). Simultaneously, the intraosseous pressure (IOP) was measured in the femoral head. For comparison, the same 2 parameters were measured in 6 normal femoral heads during surgery of the contralateral hip. In osteonecrosis, the regional blood cell flux in the intertrochanteric area was 165 mV, at the rim of the lesion 430 mV, and in the necrotic lesion 35 mV. In the same areas, the IOP was 38 mmHg, 61 mmHg and 55 mmHg. In the normal hips, the LDF signal was 221 mV and 224 mV, and the IOP was 21 mmHg and 19 mmHg intertrochanterically and in the femoral head, respectively. We conclude that the microvascular blood perfusion is uneven in an osteonecrotic head.

Distribution of 99mTc-phosphate compounds in osteonecrotic femoral heads

We examined the distribution of 99mTc-MDP in 12 late-stage nontraumatic necrotic femoral heads by autoradiography and compared this to the histology of adjacent sections. A widespread fibrocartilaginous metaplasia, and enchondral ossification was observed in the demarcation zone. The highest uptake of the isotope was seen at the provisional calcification in areas with enchondral ossification in the demarcation zone. We concluded that the uneven distribution of 99mTc-MDP was mainly due to the remodeling processes.

Pseudoaneurysm of the posterior circumflex humeral artery diagnosed by sonography

We report a rare case of a pseudoaneurysm of the posterior circumflex humeral artery, probably related to a steroid injection in the shoulder 3 months earlier. The clinical presentation was atypical and the location not previously described in the literature. The patient was referred with a painless, nonpulsatile mass in the posterior shoulder region and was suspected of a malignant soft‐tissue tumor. Sonography, including power Doppler imaging, demonstrated a pseudoaneurysm, with the intralesional blood‐filled cavity developed from the posterior circumflex humeral artery. The diagnosis was confirmed by pathologic examination of the surgical specimen.