DSC analysis of human fat tissue in alcohol-induced avascular necrosis of the femoral head: A preliminary study

The osteonecrosis or avascular necrosis of the antero-superior part of the human femoral head (ANFH) often causes incongruity in the hip joint and leads to severe pain and disability in middle aged patients. This abnormality often requires surgical intervention, mainly total hip arthroplasty (THA). The possible pathomechanisms of ANFH are fat embolism, arterial occlusion, fatty necrosis of osteocytes and intraosseous hypertension. Factors have been proposed in the literature that can lead to this condition are alcohol abuse, steroid therapy, metabolic changes, dyslipidaemia. In some case we can not verify any factor; these are the so called idiopathic ANFH cases. We observed macroscopic variation in colour and consistency of the subcutaneous fat tissue in patients with ANFH compared to osteoarthritis or hip fracture during THA procedures. Subcutaneous fat tissues during THA from a patient with ANFH due to alcohol abuse were compared with an otherwise healthy patient who underwent surgery due to traumatic hip fracture. No histological changes were notified in the size; shape of adipocytes and in the cells of the septae of the connective tissue. Gas chromatography showed that the patient with alcoholic ANFH had less long chain fatty acids. DSC revealed, that in case of non-necrotic sample as a reference, during heating between 0–100°C two separable transitions are with T m =5.7 and 9.9°C, total Δ H = −20.8 J g −1 . In −20–100°C range endotherms with T m = −10.9 and 4.95°C, total Δ H = −75.8 J g −1 could be detected. In case of alcohol-induced avascular necrosis we have found endotherms between 0–100°C with: T m =7.3°C, total Δ H = −26.9 J g −1 , and heating between −20–100°C: T m = −0.25°C, total Δ H = −103.3 J g −1 thermal parameters. The alteration in the fatty acid profile did not cause histological changes, but we were able to detect it with analytical methods e.g. DSC and gas chromatography.