Aims.
1. Regional osteoporosis is a common finding in osteoid osteoma. It may in fact be a constant feature because it was present in all the patients reported in this paper and was suspected in others who have not been included in this report because of insufficient information. 2. Five of our six cases showed osteoporosis about the hip.
1. The syndrome of osteoporosis is reviewed and its various causes are mentioned.
1. Individuals who are normal and not osteoporotic seem to show retention of cortical bone at successive decades of life in proportion to the total lean body-mass. In patients with osteoporosis the weight of the skeleton decreases at a rate exceeding the physiological rate of atrophy of muscle, tendon and bone tissue that occurs with the time-dependent process of ageing. 2. Six patients representing the typical forms of osteoporosis commonly found in orthopaedic practice were investigated intensively over a period of three years and compared with individuals in whom there was no osteoporosis by studies of metabolic balance, Sr85 osteograms, and tetracycline deposition. 3. Studies of metabolic balance in patients with osteoporosis showed normal or negative calcium balances, but an equilibrium for the metabolism of nitrogen and phosphorus. Increased intake of calcium in the diet produced retention of calcium but not sufficient phosphorus, nitrogen or gain in weight to prove that the patient had made new bone and healed the osteoporosis. 4. Radio-isotope osteograms showed high, normal or low rates of change of uptake of Sr85 and the accretion rate was calculated to be normal or low in individuals with osteoporosis. High uptake of tetracycline by a small mass of bone tissue and by a relatively small percentage of the total number of osteons suggested that in an adult human being the calcium reserve in the skeleton is enormous. Thirty to 50 per cent of the total bone mass was sufficient to turn over 0·5 to 1·0 gramme, the amount of calcium utilised in twenty-four hours by the human adult. This was accomplished by structural or old bone throughout the entire skeleton, and by labile or newer bone located in approximately 10 per cent of the total number of Haversian cylinders or osteons. 5. Some of the unclosed or half-closed osteons were hyperactive in osteoporotic bones. In the process of remodelling of cortical bone a significant quantity of bone tissue was incompletely restored and there were, presumably as a result, intermittently large or small negative calcium balances.
Relating the results of our investigations to the knowledge hitherto acquired about the etiology of osteoporosis (which I have already referred to), I am inclined to interpret the pathogenesis of osteoporosis in the following way: 1) Primary osteoblastic deficiency: congenital (Lobstein); involutive (senile osteoporosis?); 2) Reduced osteoblastic activity from absence of trophic stimuli: (inactivity, ovarian agenesia, eunuchoidism, menopause); 3) Reduced osteoblastic activity from inhibitory stimuli: (cortisone, adrenocorticotrophic hormone (A.C.T.H.), stress, Cushing's disease, thyrotoxicosis); 4) Normal osteoblastic activity but insufficiency of constructive material: (malnutrition, disturbances of the digestive system, insufficiency of vitamin C, diabetes, thyrotoxicosis, cortisone, A.C.T.H., stress, Cushing's disease).
Postoperative complication rates remain relatively high after adult spinal deformity (ASD) surgery. The extent to which modifiable patient-related factors influence complication rates in patients with ASD has not been effectively evaluated. The aim of this retrospective cohort study was to evaluate the association between modifiable patient-related factors and complications after corrective surgery for ASD. ASD patients with two-year data were included. Complications were categorized as follows: any complication, major, medical, surgical, major mechanical, major radiological, and reoperation. Modifiable risk factors included smoking, obesity, osteoporosis, alcohol use, depression, psychiatric diagnosis, and hypertension. Patients were stratified by the degree of baseline deformity (low degree of deformity (LowDef)/high degree of deformity (HighDef): below or above 20°) and age (Older/Younger: above or below 65 years). Complication rates were compared for modifiable risk factors in each age/deformity group, using multivariable logistic regression analysis to adjust for confounders.Aims
Methods
We invited 1604 randomly selected women, all 75 years of age, to participate in a study on the risk factors for fracture. The women were divided into three groups consisting of 1044 (65%) who attended the complete study, 308 (19%) respondents to the study questionnaire only and 252 (16%) who did not respond. The occurrence of the life-time fracture was ascertained from radiological records in all groups and by questionnaires from the attendees and respondents. According to the radiological records, fewer of the questionnaire respondents (88 of 308, 28.6%) and non-respondents (68 of 252, 27%) had sustained at least one fracture when compared with the attendees (435 of 1044, 41.7%; chi-squared test, p <
0.001). According to the questionnaire, fewer of the respondents (96 of 308, 31.1%) had sustained at least one previous fracture when compared with the attendees (457 of 1044, 43.7%; chi-squared test, p <
0.001). Any study concerning the risk of fracture may attract those with experience of a fracture which explains the higher previous life-time incidence among the attendees. This factor may cause bias in epidemiological studies.
While it is not denied that immobilisation of a diseased joint may be essential, there is a growing mass of evidence that immobilisation in recumbency of the whole patient has severe effects both in the neighbourhood of the actual lesion and upon the skeleton as a whole. Further search for measures to counteract the undesirable skeletal effects of recumbency is much needed.
1. Using the incidence of hip fracture as an indication of senile osteoporosis, the occurrence of this disease is found to vary greatly in different racial groups. The highest reported incidence is in Sweden, followed by Britain, Hong Kong Chinese, Singapore Chinese and South African Bantu, in that order. Likewise, the sex incidence varies, women outnumbering men in Sweden and Britain, men exceeding women in Singapore; an equal sex incidence is found in Hong Kong. 2. In all races and in both sexes the incidence is more closely related to age than any other factor, a progressive increase being noted after forty-five. Ageing is clearly the dominant etiological factor, but this does not explain the different racial incidence. These differences cannot be attributed to hormonal state or to the dietary intake of calcium, but do accord in general with the living standards of the different countries and the degree of physical activity undertaken by the different populations and sexes. 3. Hereditary factors may play a part, but further geographical study of the incidence of senile osteoporosis is necessary before the relative importance of inheritance and environment can be assessed.