OSTEOMALACIA IN THE ELDERLY
RUSH
OSTEOMALACIA IN THE ELDERLY JONATHAN
H . RUSH
St Vincents Hospital, Melbourne Over recent years i t has been demonstrated that there is a significant incidence o f osteomalacia in elderly patients presenting with fractures of the femoral neck. T h e results of a survey carried out on all patients admitted to S t Vincent’s Hospital, Melbourne, with fractures of the upper end of the femur over a I Z m o n t h period are presented, and the condition o f osteomalacia i n the elderly is dlscussed. It is concluded that in this community osteomalacia does not present as a practical problem except I n those patients who have the condition as a result o f a definite predisposing factor.
UNTILrecently, osteomalacia or adult rickets was considered an uncommon metabolic bone disease, characterized by the failure of mineralization of organic bone matrix. However, the pathology, clinical features, and treatment of the disorder have been clearly defined. A high incidence of osteomalacia is reported in some countries (e.g. India and China), in circumstances where there is a dietary deficiency of Vitamin D, lack of exposure to sunlight, and often multiple pregnancies. I n western countries, however, it was only recognized in cases of intestinal malabsorption (for example after total gastrectomy) and in certain renal disorders. In recent years a number of papers have been published, particularly from Britain, indicating that the condition is not at all uncommon in elderly women and in the migrant population (Gough et alii, 1964; Anderson et alii, 1966; Exton-Smith et alii, 1966; Chalmers et alii, 1967; Chalmers, 1968; Nordin, 1973). This increased awareness of the condition led to comment and discussion in the editorial columns of the British Medical Journal (1968) and the Lancet (1969). A study of 77 patients admitted with fractures of the femoral neck in Cardiff revealed evidence of biochemical osteomalacia in 357% of cases (Jenkins et alii, 1973). Even more recently, O’Driscoll ( 1973) has drawn attention to the high incidence of osteomalacia Address for reprints: IIO Collins Street, Melbourne, Victoria 3000.
and malnutrition among the elderly population. H e has also pointed out that femoral neck fracture is one of the common ways in which the condition may present. Chalmers (1973) reported that osteomalacia was found in 12% of patients with fractures of the upper end of the femur. I n this community the incidence of osteomalacia is unknown, although the condition is generally considered to be uncommon. To study the incidence more closely, all patients admitted to St Vincents Hospital, Melbourne, over a twelve-month period with fractures of the upper end of the femur were examined radiologically, biochemically, and histologically for possible osteomalacia. From May 1971 to May 1972 there were 136 patients admitted with fractures of ,the upper end of the femur. The mean age was 73-5 years. There were 10 males and 126 females. Clinical Features When one is considering the various features of osteomalacia, it is always important to look for any obvious predisposing factors such as diet, previous gastric or bowel surgery, and chronic renal disease. A common symptom is bone pain. It may be generalized, but particularly involves the shoulders, back, thighs, and feet. With this pain there may be associated local bone tenderness, indicating an underlying pseudofracture. I n some cases there is marked muscle weakness which is so severe that the patient may be
I%
AUST. N.Z. J. SURG.,VOL. 37-N0.
2,
APRIL, 1977
OSTEOMALACIA I N THE ELDERLY
confined to bed. This weakness responds well to treatment. Stress fractures are observed, for example in ribs, forearm bones, and the neck of the femur, and these may develop into the classical radiological sign of a Looser’s zone. Complete fractures (e.g. subcapital fracture of the neck of the femur) occur, and without treatment for the osteomalacia, these fractures are very slow to unite. Skeletal deformities such as generalized kyphosis and rib cage deformities are also seen in the condition. In this series all the patients presented with a fracture of the upper end of the femur, but there were no patients with other clinical features suggestive of osteomalacia.
Radiological Features The radiological appearances in osteomalacia are fairly characteristic : there is generalized demineralization of bone, with loss of normal trabecular pattern. Looser zones are diagnostic of osteomalacia. These represent bands of unmineralized bone matrix in a fracture callus associated with a stress fracture or minor injury. They are seen on the concave borders of bones and occur in that part of the bone which is subject to compression. Most of these fractures can be seen in skiagrams of the chest and pelvis. In this series of 136 patients, skiagrams of the chest and pelvis were performed routinely. In most of the films there was evidence of generalized osteoporosis, but only in three patients were the findings suspicious of osteomalacia in that the normal trabecular pattern was lost and the cortical margins were poorly defined. These three patients, however, did not show any of the other features of osteomalacia. Biochemical Features Biochemical changes in osteomalacia are important and often diagnostic. There may be a low serum phosphorus level, a low serum calcium level, or both. A raised serum alkaline phosphatase level is often present. This raised alkaline phosphatase is a measure of osteoblastic activity, and it may be present in other abnormal conditions of bone, such as Paget’s disease. The serum calcium, phosphorus and alkaline phosphatase levels were measured in all the AuST.
N.Z. J.
SURG., VOL.
47-NO.
2,
APRIL, 1977
RUSH
patients. In only one patient was there definite evidence of osteomalacia, with findings of a serum calcium level of 7-2 mg/Ioo ml, inorganic phosphorus 2.2 mg/Ioo ml, and an alkaline phosphatase level of 19 KA units/Ioo ml. This patient had definite evidence of malabsorption syndrome following a partial gastrectomy many years previously.
Histological Features Osteomalacia is recognized histologically by the presence of abnormal amounts of bone matrix or osteoid which have failed to mineralize. Excessive amounts of osteoid can be seen in many other conditions where the rate of bone formation is increased, e.g., Paget’s disease, but most of these conditions have other distinguishing histological features. In this study, at the operation for the fractured femur, a trephine biopsy of the greater trochanter was undertaken, and this usually gave a good sample of cancellous bone. In 36 cases the surgeon forgot to take the specimen. Biopsy, however, was performed on 100 patients. I n ten cases the specimens were unsatisfactory, so that go specimens were available for histological examination. The sections were prepared by embedding the undecalcified sample of bone in methyl methacrylate and staining by Von Kossa impregnation (Sissons, 1968). I n the go specimens examined there was only one in which there was histological evidence of osteomalacia. This showed some widening of the osteoid seams, although the changes were not very marked. This patient also had biochemical evidence of osteomalacia. A number of different techniques have been used to assess the amount of osteoid necessary to justify the diagnosis of osteomalacia. Such techniques were not necessary in this series, as in only the single patient mentioned was there any evidence at all of a significant osteoid seam.
DISCUSSION These results have demonstrated that osteomalacia is not a problem in this community in elderly patients with fractures of the upper end of the femur. This is in direct contrast to the reports of a significant incidence in similar surveys in Britain (Jenkins et alii, 1973; Chalmers, 1973).
RUSH
OSTEOMALACIA I N THE ELDERLY
On the other hand, senile osteoporosis remains a serious problem. In this condition normal mineralization of bone matrix occurs, but there is a decrease in the amount of bone per unit volume. The majority of patients with femoral neck fractures in this series had radiological evidence of significant osteoporosis. While bone biopsy is important in the diagnosis of osteomalacia, routine histological examination i s not particularly helpful in establishing the diagnosis of osteoporosis. I t is important to know if osteomalacia is present in any particular patient, because if it is left untreated there will be difficulty in achieving satisfactory union. With treatment the condition is readily controlled. I n the Melbourne metropolitan area, however, it does not seem worthwhile investigating patients with fractured femoral necks biochemically and histologically unless there is some definite predisposing factor such as a malabsorption state. The explanation for the difference in the incidence of this condition in Australia and in Britain is presumably the presence in this country of adequate sunlight. As Chalmers (1969) pointed out: “in Hong Kong, for example, the average Chinese diet contains less than 70 IU/day of Vitamin D and yet osteomalacia is excessively rare owing to the generous exposure to sunshine enjoyed in that part of the world.”
Our foster-nurse of nature is repose, The which he lacks; that to provoke in him Are many simples operative, whose power Will close the eye of anguish.
I88
ACKNOWLEDGEMENTS I should like to thank Mr W. R. Gayton and Mr H. V. Crock, Orthopadic Surgeons, St Vincents Hospital, Melbourne, for permission to study patients admitted under their care. The histological sections and subsequent examinations were performed under the direction of D r Sheila Clifton, Assistant Pathologist, S t Vincents Hospital, Melbourne.
REFERENCES ANDERSON, I., CAMPBELL, A. E. R., DUNN,A. and RUNCINAN, J. B. M. (1966), Scot. med. J., 11: 49. RnITIsH MEDTCAL JOURNAL (1@8), Editorial, 2 : 130. CHALMERS,J., CONACHER, W. D. H., GARDNER, D. and SCOTT, P. J. (1967), 1. Bone J t Surg., 49B: 403.
CHALMERS, J. (1968), J . roy. Coll. Szrrg. Edinb., 13: 25.5. CHALMERS, J. (1969), Lancet, I : 1150. CHALMERS, J. (1973), J . Bone J t Surg., 5 5 ~ 882. : EXTON-SMITH, A. N., HODKINSON, H. M. and STANTON, B. R. (1966), Lawet, 2 : 999. GOUGH.K. R.. LLOYD.0. C. and WILLS.M. R. (1964), Lancet, 2 :’ 1261. JENKINS, D. H. R., ROBERTS, J. G., WEBSTER, D. and WILLIAMS, E. 0. (1973), J . Bone J t Sttry., 558: 575. LANCET(1969)~Editorial, I : 1037. NORDIN,B. E. C. (1973), Metabolic Bone and Stone Disease. Churchill Livingstone, London : 72. O’DRISCOLL, M. (IQ73), J . Bone J t Surg., 5533: 882. SISSONS, H. A. (1968)~Preparation of Undecalcified Bone Sections, Association of Clinical Pathologists, Broadsheet 62, January 1968.
William Shakespeare, King Lccir, IV, IV
AUST. N.Z. J. SURG., VOL.47-N0.
2,
APRIL, 1977
RUSH
OSTEOMALACIA IN THE ELDERLY JONATHAN
H . RUSH
St Vincents Hospital, Melbourne Over recent years i t has been demonstrated that there is a significant incidence o f osteomalacia in elderly patients presenting with fractures of the femoral neck. T h e results of a survey carried out on all patients admitted to S t Vincent’s Hospital, Melbourne, with fractures of the upper end of the femur over a I Z m o n t h period are presented, and the condition o f osteomalacia i n the elderly is dlscussed. It is concluded that in this community osteomalacia does not present as a practical problem except I n those patients who have the condition as a result o f a definite predisposing factor.
UNTILrecently, osteomalacia or adult rickets was considered an uncommon metabolic bone disease, characterized by the failure of mineralization of organic bone matrix. However, the pathology, clinical features, and treatment of the disorder have been clearly defined. A high incidence of osteomalacia is reported in some countries (e.g. India and China), in circumstances where there is a dietary deficiency of Vitamin D, lack of exposure to sunlight, and often multiple pregnancies. I n western countries, however, it was only recognized in cases of intestinal malabsorption (for example after total gastrectomy) and in certain renal disorders. In recent years a number of papers have been published, particularly from Britain, indicating that the condition is not at all uncommon in elderly women and in the migrant population (Gough et alii, 1964; Anderson et alii, 1966; Exton-Smith et alii, 1966; Chalmers et alii, 1967; Chalmers, 1968; Nordin, 1973). This increased awareness of the condition led to comment and discussion in the editorial columns of the British Medical Journal (1968) and the Lancet (1969). A study of 77 patients admitted with fractures of the femoral neck in Cardiff revealed evidence of biochemical osteomalacia in 357% of cases (Jenkins et alii, 1973). Even more recently, O’Driscoll ( 1973) has drawn attention to the high incidence of osteomalacia Address for reprints: IIO Collins Street, Melbourne, Victoria 3000.
and malnutrition among the elderly population. H e has also pointed out that femoral neck fracture is one of the common ways in which the condition may present. Chalmers (1973) reported that osteomalacia was found in 12% of patients with fractures of the upper end of the femur. I n this community the incidence of osteomalacia is unknown, although the condition is generally considered to be uncommon. To study the incidence more closely, all patients admitted to St Vincents Hospital, Melbourne, over a twelve-month period with fractures of the upper end of the femur were examined radiologically, biochemically, and histologically for possible osteomalacia. From May 1971 to May 1972 there were 136 patients admitted with fractures of ,the upper end of the femur. The mean age was 73-5 years. There were 10 males and 126 females. Clinical Features When one is considering the various features of osteomalacia, it is always important to look for any obvious predisposing factors such as diet, previous gastric or bowel surgery, and chronic renal disease. A common symptom is bone pain. It may be generalized, but particularly involves the shoulders, back, thighs, and feet. With this pain there may be associated local bone tenderness, indicating an underlying pseudofracture. I n some cases there is marked muscle weakness which is so severe that the patient may be
I%
AUST. N.Z. J. SURG.,VOL. 37-N0.
2,
APRIL, 1977
OSTEOMALACIA I N THE ELDERLY
confined to bed. This weakness responds well to treatment. Stress fractures are observed, for example in ribs, forearm bones, and the neck of the femur, and these may develop into the classical radiological sign of a Looser’s zone. Complete fractures (e.g. subcapital fracture of the neck of the femur) occur, and without treatment for the osteomalacia, these fractures are very slow to unite. Skeletal deformities such as generalized kyphosis and rib cage deformities are also seen in the condition. In this series all the patients presented with a fracture of the upper end of the femur, but there were no patients with other clinical features suggestive of osteomalacia.
Radiological Features The radiological appearances in osteomalacia are fairly characteristic : there is generalized demineralization of bone, with loss of normal trabecular pattern. Looser zones are diagnostic of osteomalacia. These represent bands of unmineralized bone matrix in a fracture callus associated with a stress fracture or minor injury. They are seen on the concave borders of bones and occur in that part of the bone which is subject to compression. Most of these fractures can be seen in skiagrams of the chest and pelvis. In this series of 136 patients, skiagrams of the chest and pelvis were performed routinely. In most of the films there was evidence of generalized osteoporosis, but only in three patients were the findings suspicious of osteomalacia in that the normal trabecular pattern was lost and the cortical margins were poorly defined. These three patients, however, did not show any of the other features of osteomalacia. Biochemical Features Biochemical changes in osteomalacia are important and often diagnostic. There may be a low serum phosphorus level, a low serum calcium level, or both. A raised serum alkaline phosphatase level is often present. This raised alkaline phosphatase is a measure of osteoblastic activity, and it may be present in other abnormal conditions of bone, such as Paget’s disease. The serum calcium, phosphorus and alkaline phosphatase levels were measured in all the AuST.
N.Z. J.
SURG., VOL.
47-NO.
2,
APRIL, 1977
RUSH
patients. In only one patient was there definite evidence of osteomalacia, with findings of a serum calcium level of 7-2 mg/Ioo ml, inorganic phosphorus 2.2 mg/Ioo ml, and an alkaline phosphatase level of 19 KA units/Ioo ml. This patient had definite evidence of malabsorption syndrome following a partial gastrectomy many years previously.
Histological Features Osteomalacia is recognized histologically by the presence of abnormal amounts of bone matrix or osteoid which have failed to mineralize. Excessive amounts of osteoid can be seen in many other conditions where the rate of bone formation is increased, e.g., Paget’s disease, but most of these conditions have other distinguishing histological features. In this study, at the operation for the fractured femur, a trephine biopsy of the greater trochanter was undertaken, and this usually gave a good sample of cancellous bone. In 36 cases the surgeon forgot to take the specimen. Biopsy, however, was performed on 100 patients. I n ten cases the specimens were unsatisfactory, so that go specimens were available for histological examination. The sections were prepared by embedding the undecalcified sample of bone in methyl methacrylate and staining by Von Kossa impregnation (Sissons, 1968). I n the go specimens examined there was only one in which there was histological evidence of osteomalacia. This showed some widening of the osteoid seams, although the changes were not very marked. This patient also had biochemical evidence of osteomalacia. A number of different techniques have been used to assess the amount of osteoid necessary to justify the diagnosis of osteomalacia. Such techniques were not necessary in this series, as in only the single patient mentioned was there any evidence at all of a significant osteoid seam.
DISCUSSION These results have demonstrated that osteomalacia is not a problem in this community in elderly patients with fractures of the upper end of the femur. This is in direct contrast to the reports of a significant incidence in similar surveys in Britain (Jenkins et alii, 1973; Chalmers, 1973).
RUSH
OSTEOMALACIA I N THE ELDERLY
On the other hand, senile osteoporosis remains a serious problem. In this condition normal mineralization of bone matrix occurs, but there is a decrease in the amount of bone per unit volume. The majority of patients with femoral neck fractures in this series had radiological evidence of significant osteoporosis. While bone biopsy is important in the diagnosis of osteomalacia, routine histological examination i s not particularly helpful in establishing the diagnosis of osteoporosis. I t is important to know if osteomalacia is present in any particular patient, because if it is left untreated there will be difficulty in achieving satisfactory union. With treatment the condition is readily controlled. I n the Melbourne metropolitan area, however, it does not seem worthwhile investigating patients with fractured femoral necks biochemically and histologically unless there is some definite predisposing factor such as a malabsorption state. The explanation for the difference in the incidence of this condition in Australia and in Britain is presumably the presence in this country of adequate sunlight. As Chalmers (1969) pointed out: “in Hong Kong, for example, the average Chinese diet contains less than 70 IU/day of Vitamin D and yet osteomalacia is excessively rare owing to the generous exposure to sunshine enjoyed in that part of the world.”
Our foster-nurse of nature is repose, The which he lacks; that to provoke in him Are many simples operative, whose power Will close the eye of anguish.
I88
ACKNOWLEDGEMENTS I should like to thank Mr W. R. Gayton and Mr H. V. Crock, Orthopadic Surgeons, St Vincents Hospital, Melbourne, for permission to study patients admitted under their care. The histological sections and subsequent examinations were performed under the direction of D r Sheila Clifton, Assistant Pathologist, S t Vincents Hospital, Melbourne.
REFERENCES ANDERSON, I., CAMPBELL, A. E. R., DUNN,A. and RUNCINAN, J. B. M. (1966), Scot. med. J., 11: 49. RnITIsH MEDTCAL JOURNAL (1@8), Editorial, 2 : 130. CHALMERS,J., CONACHER, W. D. H., GARDNER, D. and SCOTT, P. J. (1967), 1. Bone J t Surg., 49B: 403.
CHALMERS, J. (1968), J . roy. Coll. Szrrg. Edinb., 13: 25.5. CHALMERS, J. (1969), Lancet, I : 1150. CHALMERS, J. (1973), J . Bone J t Surg., 5 5 ~ 882. : EXTON-SMITH, A. N., HODKINSON, H. M. and STANTON, B. R. (1966), Lawet, 2 : 999. GOUGH.K. R.. LLOYD.0. C. and WILLS.M. R. (1964), Lancet, 2 :’ 1261. JENKINS, D. H. R., ROBERTS, J. G., WEBSTER, D. and WILLIAMS, E. 0. (1973), J . Bone J t Sttry., 558: 575. LANCET(1969)~Editorial, I : 1037. NORDIN,B. E. C. (1973), Metabolic Bone and Stone Disease. Churchill Livingstone, London : 72. O’DRISCOLL, M. (IQ73), J . Bone J t Surg., 5533: 882. SISSONS, H. A. (1968)~Preparation of Undecalcified Bone Sections, Association of Clinical Pathologists, Broadsheet 62, January 1968.
William Shakespeare, King Lccir, IV, IV
AUST. N.Z. J. SURG., VOL.47-N0.
2,
APRIL, 1977
