J. C. BiRKENHAGER et dl.: Studics of Iliac Crest Bone 73 



Studies of Iliac Crest Bone from Controls and Patients with Bone 



Disease by Means of Chemical Analysis, Tetracycline Labelling 



and Histology 



J. C. BiRKENHAGER, J. VAN DER SlUYS VeER, R. O. VAN DER HeUL, D. SmEENK 



Department for Clinical Endocrinology and Metabolism and Department for Pathology, 

 Acadcmisch Ziekenhuis, Leiden, Nederland. 



1, Introduction 



In 1964 VAN DER Sluys Veer et ai, showed that in hyperparathyroidism tetra- 

 cycline labelling of iliac crest bone is Increased in the majority of cases. 



In Cushing's syndrome tetracycline uptake by bone was found to vary from 

 values below to values definitively above the normal range even among cases with 

 the same degree of osteoporosis as measured histologically (van der Heul et ai, 

 1964). 



In the present study of bone from cases of hyperparathyroidism or hyperadreno- 

 corticism we have tried to correlate the degree of mineralization assessed by chemical 

 methods with the degree of tetracycline labelling. 



2. Material and methods 



The study comprised iliac crest bone biopsy material from eighteen patients with 

 hyperparathyroidism, eleven patients with Cushing's syndrome, three patients who 

 were treated with high doses of prednisone and thirteen controls. The material from 

 the controls was not submitted to a tetracycline uptake study. 



The method of measurement of tetracycline uptake and the histological methods 

 have been described earlier (van der Sluys Veer et al., 1964). For chemical analysis 

 a small part of cancellous bone was ground and washed with distilled water. After 

 defatting and powdering the bone was freed of water by drying to a constant weight 

 over anhydrous potassium carbonate (Birkenhager-Frenkel et ai, 1961). The bone 

 was hydrolysed for five hours at 140 "C with 6N hydrochloric acid. Phosphorus 

 (Fiske and Subbarow, 1925, modified) and hydroxyproline (Kivirikko and Liesmaa, 

 1959) were estimated after neutralization with sodium hydroxide. 



3. Results 



A. Hyperparathyroidism 



In the cases of hyperparathyroidism a high percentage of tetracycline labelled 

 bone surface (average 32o/o, range 16 — 49''/o) was found. This confirms the results 

 of earlier studies when an average of 25''/o was found in eighteen cases of hyper- 

 parathyroidism and an average of 12Vo in seventeen controls (van der Sluys Veer 

 ct ai, 1964). Histologically in nearly all cases an increase in the number of osteo- 

 blasts, osteoclasts, osteoid seams and fibrosis was seen. 



The results of the chemical analysis in hyperparathyroidism and in the control 

 group are shown in Fig. 1. The phosphorus content averaged 92.4 (range 80.8 to 

 100.9) //g per mg (hydrated) bone in hyperparathyroidism and 100.7 (range 97.3 to 

 103.3) iig per mg bone in the controls. 



