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A simple radiological screening method for assessment of osteoporosis
A Simple Radiological Screening Method for Assessment of Osteoporosis H. Pogrund, M. Makin, G. Robin, J. Menczel, M. Rousso and R. Steinberg A SIMPLE RADIOLOGICAL SCREENING METHOD FOR ASSESSMENT OF O S T E O P O R O S I S
H. P O G R U N D , M. M A K I N , G. ROBIN, J. M E N C Z E L , M. ROUSSO, and R. S T E I N B E R G , Jerusalem, Israel SUMMARY A simple radiological grading o f osteoporosis o f the hand using a posteroanterior radiograph is presented as a screening technique. Five gradings are discussed, and the relationship o f osteoporosis between the hand and axial portions o f the skeleton is underlined. INTRODUCTION
One of the problems in research into osteoporosis is the difficulty in measuring its degree. Many techniques have been used, including biopsy of bone, densitometry, and simple visual evaluation and measurement. The latter method is subjective, and depends on the quality of the X-ray and the thickness of the soft tissue layer in the patient. A reasonably satisfactory estimate of osteoporosis has been by the use of Smith's criteria (1966) for the spine, comprising five degrees, ranging from 0 or normal to grade 4 - - severe osteoporosis. While subjective phenomena play a part in the assessment of X-rays of the spine it makes accurate and reproducible assessment difficult to obtain. The hand, with its minimal soft tissue cover and small bone structure, is more suitable for visual appraisal of the degree of osteoporosis. Cortical index (CI) measurements have been used frequently in the assessment of osteoporosis. This technique however requires accurate measurement and marked variability has been shown in the results (Naor 1971). Recently we have been using a visual technique for the assessment of osteoporosis in the hand with a good correlation with the cortical index. The method is quick, requires no special instrumentation other than an X-ray and appears to be reasona61y accurate. The method was used in a previous study in the comparison of osteoporosis in different sites of the skeleton, i.e. hand, pelvis and spine. We have now expanded the grading criteria and present this method as a simple and convenient measure of osteoporosis in the hand. MATERIAL AND METHODS
Seventy-one postero-anterior X-rays of the non-dominant hand were examined. Postero-anterior views were taken on normal film at 90 cm distance using 38 Kv. The X-rays studied were randomly selected from a consecutive series of patients (aged thirty years or more) admitted to hospital with a fractured neck of the femur. The area which was examined in the hand X-ray was the, metacarpal zone of all the digits. The carpus and phalanges were not used for assessing osteoporosis because of possible variation due to disease processes involving the finger joint or" carpus. The X-rays were examined independently by three observers and an agreed rating decided. The following criteria were employed (Fig. 1-5): H. Pogrund, F.R.C.S., The Osteoporosis Institute and Hand Unit, Hadassah University Hospital, Jerusalem, Israel. 9 1981 British Society for Surgery of the Hand 0072-968X-81-00070043 $02.00 The Hand-- Volume 13
No. 1
1981
43
A Simple Radiological Screening Method for Assessment o f Osteoporosis H. Pogrund, M. Makin, G. Robin, J. Menczel, M. Rousso and R. Steinberg
Figs 1-5. Showing the normal appearance and increasing degree of osteoporosis of the hand. Grading is from 0 to 5. Arrow points to sclerotic area in head of metacarpal which tends to become less obvious or disappears with increasing degrees of osteoporosis. The aluminium grading strip was not used in these estimations.
44
The Hand-- Volume 13
No. 1
1981
A Simple Radiological Screening Method f o r Assessment o f Osteoporosis H. Pogrund, M~ Makin, G. Robin, J. Menezel, M. Rousso and R. Steinberg
Grade 0
Grade 1
Grade 2
Grade 3
Grade 4
Excellent cortices, wide and sclerotic looking. No apparent loss of general bone density. Trabeculation (vertical and horizontal) at base of metacarpals no less eviden~ than~normal. Cortex giving impression of slight thinning, especially in metacarpals 1 and 5, or both. No apparent loss of general density but impression of ground glass like appearance in proximal third of metacarpals, again 1 an d 5 . Cortical thinning now apparent in m o s t metacarpals, with medullary width increase. Overall bone density loss evident with ground glass appearance extending distally along metacarpals. Vertical trabeculae at bases now more pronounced. Cortical thinning more definite in all metacarpals, increase in medullary width definite. Overall loss of bone density with obvious ground glass appearance along full length of metacarpals. Vertical trabeculae at bases becoming less marked. 'Bracket' sign less obvious. Cortical thinning and medullary width increased in all metacarpals. Loss of bone density complete. Trabeculae at bases now absent. 'Bracket' sign very fine or nearly absent.
The 'bracket' sign comprises a C-shaped sclerotic area in the head of the metacarpal on X-ray, produced by the lateral notch for the collateral ligaments. We have observed that in gross porosis of the hand this becomes less marked or even disappears. The third metacarpal was used for reading the cortical index. The thickness of the two cortices of the metacarpal was measured at its mid-point and the sum of the two measurements divided by the total metacarpal thickness at the same point. The resulting figure is known as the cortical index. RESULTS
Of seventy one hands, twenty (28%) were non osteoporotic, while twenty (28%) were grade one. Thirteen (18%) belonged to grade two and fourteen (20%) to grade three. Four (6~ were in the fourth grade. In the whole group the cortical index ranged from 0.44-0.22 (Fig. 6). A significant statistical difference was noted between the mean cortical index in the osteoporotic and non-osteoporotic groups (Students' t test) (p<0.05). There appeared to be a good relationship between the degree of osteoporosis of the hand and the cortical index reading in each group. W-Kendall coefficient of concordance expresses the degree of association (p<0.05). Degrees of spinal osteoporosis were read for the same groups of patients employing the criteria of Smith (1966), and a rising frequency of spinal osteoporosis was noted in the different groups with increasing degrees of hand osteoporosis (Chi square p<0.05). When definite osteoporosis of the hand was noted, the probability of the presence of spinal osteoporosis rose to 80%. Of seventy one patients, there were six with compression fractures of the spine, three of whom had definite osteoporosis of the hand, two with grade one osteoporosis and only one had no osteoporosis at all. The Hand-- Volume 13
No. 1
1981
45
A Simple Radiological Screening Method for Assessment o f Osteoporosis H. Pogrund, M. Makin, G. Robin, J. Menczel, M. Rousso and R. Steinberg
DISCUSSION It has been shown that with increasing age, skeletal density in various bones of the skeleton decreases at similar rates (Trotter 1960). This is due to the loss of bone mass as a consequence of cortical thinning and increased rarefaction of trabeeular bone in the epiphyses. Grading systems employing the change in trabecular picture have been designed for assessing the degree of osteoporosis (Hall, 1961; Helel~t, 1969; Singh, 1970). An assessment of the amount of bone in the hip region or spine, (that is, in those areas of most clinical significance) may provide a scale of the strength of bone in these zones, and therefore relate to the chances of fracture in these regions. The relationship between osteoporosis in the axial and appendicular skeleton is widely appreciated, and in fact formulae have been postulated to estimate the ratio of the bone mass of parts of the axial skeleton to the mass of the peripheral bones (Mazess, 1968; Horsman, 1970). In a study by Goldsmith (1971) in which all methods applied at the sites examined were considered, the bone sites most closely reflecting spinal osteoporosis were the radius, the middle phalanx of the little finger and the olecranon. The mid portion and distal portion of the radius, examined by a 12sI absorption scan and the middle portion of the little finger examined by roentgenograms, were found to be the sites and methods most likely to reflect osteoporosis of the spine. They rated these methods diagnostic. Wilson (1977) concluded that the bone mineral content estimation of the radius provided a good estimate of the bone mineral content of the femoral neck or the spine. The value of determining the bone mineral content of the radius lies in identifying individuals at risk for spontaneous fractures. An individual with low bone mineral content of the radius is much more likely to have low bone mineral content of the femoral neck or spine than a person w i t h normal bone mineral content of the radius. The relationship between bone mineral of the upper limb and that of the hip or spine is not sufficient for accurate prediction of bone mineral content of the femoral neck o r spine, but one can, on the basis of the relationship, assign any individual to o n e / o f two broad classes - - that is, osteopenic or nonosteopenic. In a previous paper, (Pogi'und 1979) we investigated the relationship o f osteoporosis of the spine and hand using radiological criteria. We concluded that if osteoporosis of the hand is detected, it is very likely that osteoporosis o f the spine will be present. One the contrary, however, the absence of measurable osteoporosis of the hand did not exclude the p6ssibility of osteoporosis of the spine but made its presence much less likely. On the above basis, therefore, we feel that the radiological assessment o f osteoporosis of the hand provides a simple, rapid and highly satisfactory screening technique to be used before embarking on a battery of roentgenological and other more complex investigations in the suspect individual. ACKNOWLEDGEMENT This study was supported by foreign research agreement Nos. 1-AM-3-2204 and BSS-ACP-1S-1 Department of Health, Education and Welfare, Public Health Service National Institutes of Health, United States Government. 46
The Hand-- Volume 13
No. 1
1981
A Simple Radiological Screening Method for Assessment of Osteoporosis H. Pogrund, M. Makin, G. Robin, J. Menczel, M. Rousso and R. Steinberg
REFERENCES GOLDSMITH, N. F., JOHNSTON, J. O., URY, H., VOSE, G. and COLBERT, C. (1971) Bone Mineral Estimation in Normal and Osteoporotic Women. A Comparability Trial of Four Methods and Seven Bone Sites. The Journal of Bone and Joint Surgery, 53A: 83-100. HALL, M. C. (1961) The Trabecular Patterns Of The Neck Of The Femur With Particular Reference To Changes In Osteoporosis. The Canadian Medical Association Journal, 85:1141-1144. HELELA, T., TELKKA, A. and VIRTAMA, P. (1969) Bone Pattern of the Femoral Neck as a Measure Of Bone Density And Susceptibility To Hip Fractures. Annals of Clinical Research, 1: 85-87. HORSMAN, A. L., BULUSU, L., BENTLY, H. B. and NORDIN, B.E.C. (1970) Internal Relationships Between Skeletal Parameters in Twenty Three Male Skeletons. ed. Cameron, J. R. Proceedings of Bone Measurement Conference. USA. AEC Division of Technical Information. AEC Conf. - 700515. MAZESS, R. B. (1968) Estimation of bone and skeletal weight by the direct photon absorptiometric method. American Journal of Physical Anthropology, 29: 133. NAOR, E., DI SEGNI, V., ROBIN, G., MAKIN, M. and MENCZEL, J. (1971) Intra-observer Variability in the Determination of the Metacarpal Cortical Index. The British Journal of Radiology, 45; 213-217. POGRUND, H., MAKIN, M., ROBIN, G., MENCZEL, J. and STEINBERG, R. (1979) Osteoporosis of the Spine, Pelvis and Hand. A Comparative Study in a Femoral Neck Fracture Series. Clinical Orthopaedics and Related Research. 139: 156-163. SINGH, M., NAGRATH, A. R. and MAINI, P. S. (1970) Changes in Trabecular Pattern of the Upper End of the Femur as an Index of Osteoporosis. The Journal of Bone and Joint Surgery, 53-A: 457-467. SMITH, R. W. Jr. and RIZEK, J. (1966) Epidemiological Studies of Osteoporosis in Women of Puerto Rico and South Eastern Michigan with Special Reference to Age, Race, National Origin and to Other Related or Associated Findings. Clinical Orthopaedic and Related Research, 45: 31-48. TROTTER, M., BROMAN, G. E. and PETERSON, R. R. (1960) Densities of Bones of White and Negro Skeletons. The Journal of Bone Joint Surgery, 42-A: 50-58. WILSON, C. R. (1977) Bone-Mineral Content of the Femoral Neck and Spine versus the Radius or Ulna. The Journal of Bone Joint Surgery, 59-A: 665-669.
The Hand-- Volume 13
No. 1
1981
47
H. P O G R U N D , M. M A K I N , G. ROBIN, J. M E N C Z E L , M. ROUSSO, and R. S T E I N B E R G , Jerusalem, Israel SUMMARY A simple radiological grading o f osteoporosis o f the hand using a posteroanterior radiograph is presented as a screening technique. Five gradings are discussed, and the relationship o f osteoporosis between the hand and axial portions o f the skeleton is underlined. INTRODUCTION
One of the problems in research into osteoporosis is the difficulty in measuring its degree. Many techniques have been used, including biopsy of bone, densitometry, and simple visual evaluation and measurement. The latter method is subjective, and depends on the quality of the X-ray and the thickness of the soft tissue layer in the patient. A reasonably satisfactory estimate of osteoporosis has been by the use of Smith's criteria (1966) for the spine, comprising five degrees, ranging from 0 or normal to grade 4 - - severe osteoporosis. While subjective phenomena play a part in the assessment of X-rays of the spine it makes accurate and reproducible assessment difficult to obtain. The hand, with its minimal soft tissue cover and small bone structure, is more suitable for visual appraisal of the degree of osteoporosis. Cortical index (CI) measurements have been used frequently in the assessment of osteoporosis. This technique however requires accurate measurement and marked variability has been shown in the results (Naor 1971). Recently we have been using a visual technique for the assessment of osteoporosis in the hand with a good correlation with the cortical index. The method is quick, requires no special instrumentation other than an X-ray and appears to be reasona61y accurate. The method was used in a previous study in the comparison of osteoporosis in different sites of the skeleton, i.e. hand, pelvis and spine. We have now expanded the grading criteria and present this method as a simple and convenient measure of osteoporosis in the hand. MATERIAL AND METHODS
Seventy-one postero-anterior X-rays of the non-dominant hand were examined. Postero-anterior views were taken on normal film at 90 cm distance using 38 Kv. The X-rays studied were randomly selected from a consecutive series of patients (aged thirty years or more) admitted to hospital with a fractured neck of the femur. The area which was examined in the hand X-ray was the, metacarpal zone of all the digits. The carpus and phalanges were not used for assessing osteoporosis because of possible variation due to disease processes involving the finger joint or" carpus. The X-rays were examined independently by three observers and an agreed rating decided. The following criteria were employed (Fig. 1-5): H. Pogrund, F.R.C.S., The Osteoporosis Institute and Hand Unit, Hadassah University Hospital, Jerusalem, Israel. 9 1981 British Society for Surgery of the Hand 0072-968X-81-00070043 $02.00 The Hand-- Volume 13
No. 1
1981
43
A Simple Radiological Screening Method for Assessment o f Osteoporosis H. Pogrund, M. Makin, G. Robin, J. Menczel, M. Rousso and R. Steinberg
Figs 1-5. Showing the normal appearance and increasing degree of osteoporosis of the hand. Grading is from 0 to 5. Arrow points to sclerotic area in head of metacarpal which tends to become less obvious or disappears with increasing degrees of osteoporosis. The aluminium grading strip was not used in these estimations.
44
The Hand-- Volume 13
No. 1
1981
A Simple Radiological Screening Method f o r Assessment o f Osteoporosis H. Pogrund, M~ Makin, G. Robin, J. Menezel, M. Rousso and R. Steinberg
Grade 0
Grade 1
Grade 2
Grade 3
Grade 4
Excellent cortices, wide and sclerotic looking. No apparent loss of general bone density. Trabeculation (vertical and horizontal) at base of metacarpals no less eviden~ than~normal. Cortex giving impression of slight thinning, especially in metacarpals 1 and 5, or both. No apparent loss of general density but impression of ground glass like appearance in proximal third of metacarpals, again 1 an d 5 . Cortical thinning now apparent in m o s t metacarpals, with medullary width increase. Overall bone density loss evident with ground glass appearance extending distally along metacarpals. Vertical trabeculae at bases now more pronounced. Cortical thinning more definite in all metacarpals, increase in medullary width definite. Overall loss of bone density with obvious ground glass appearance along full length of metacarpals. Vertical trabeculae at bases becoming less marked. 'Bracket' sign less obvious. Cortical thinning and medullary width increased in all metacarpals. Loss of bone density complete. Trabeculae at bases now absent. 'Bracket' sign very fine or nearly absent.
The 'bracket' sign comprises a C-shaped sclerotic area in the head of the metacarpal on X-ray, produced by the lateral notch for the collateral ligaments. We have observed that in gross porosis of the hand this becomes less marked or even disappears. The third metacarpal was used for reading the cortical index. The thickness of the two cortices of the metacarpal was measured at its mid-point and the sum of the two measurements divided by the total metacarpal thickness at the same point. The resulting figure is known as the cortical index. RESULTS
Of seventy one hands, twenty (28%) were non osteoporotic, while twenty (28%) were grade one. Thirteen (18%) belonged to grade two and fourteen (20%) to grade three. Four (6~ were in the fourth grade. In the whole group the cortical index ranged from 0.44-0.22 (Fig. 6). A significant statistical difference was noted between the mean cortical index in the osteoporotic and non-osteoporotic groups (Students' t test) (p<0.05). There appeared to be a good relationship between the degree of osteoporosis of the hand and the cortical index reading in each group. W-Kendall coefficient of concordance expresses the degree of association (p<0.05). Degrees of spinal osteoporosis were read for the same groups of patients employing the criteria of Smith (1966), and a rising frequency of spinal osteoporosis was noted in the different groups with increasing degrees of hand osteoporosis (Chi square p<0.05). When definite osteoporosis of the hand was noted, the probability of the presence of spinal osteoporosis rose to 80%. Of seventy one patients, there were six with compression fractures of the spine, three of whom had definite osteoporosis of the hand, two with grade one osteoporosis and only one had no osteoporosis at all. The Hand-- Volume 13
No. 1
1981
45
A Simple Radiological Screening Method for Assessment o f Osteoporosis H. Pogrund, M. Makin, G. Robin, J. Menczel, M. Rousso and R. Steinberg
DISCUSSION It has been shown that with increasing age, skeletal density in various bones of the skeleton decreases at similar rates (Trotter 1960). This is due to the loss of bone mass as a consequence of cortical thinning and increased rarefaction of trabeeular bone in the epiphyses. Grading systems employing the change in trabecular picture have been designed for assessing the degree of osteoporosis (Hall, 1961; Helel~t, 1969; Singh, 1970). An assessment of the amount of bone in the hip region or spine, (that is, in those areas of most clinical significance) may provide a scale of the strength of bone in these zones, and therefore relate to the chances of fracture in these regions. The relationship between osteoporosis in the axial and appendicular skeleton is widely appreciated, and in fact formulae have been postulated to estimate the ratio of the bone mass of parts of the axial skeleton to the mass of the peripheral bones (Mazess, 1968; Horsman, 1970). In a study by Goldsmith (1971) in which all methods applied at the sites examined were considered, the bone sites most closely reflecting spinal osteoporosis were the radius, the middle phalanx of the little finger and the olecranon. The mid portion and distal portion of the radius, examined by a 12sI absorption scan and the middle portion of the little finger examined by roentgenograms, were found to be the sites and methods most likely to reflect osteoporosis of the spine. They rated these methods diagnostic. Wilson (1977) concluded that the bone mineral content estimation of the radius provided a good estimate of the bone mineral content of the femoral neck or the spine. The value of determining the bone mineral content of the radius lies in identifying individuals at risk for spontaneous fractures. An individual with low bone mineral content of the radius is much more likely to have low bone mineral content of the femoral neck or spine than a person w i t h normal bone mineral content of the radius. The relationship between bone mineral of the upper limb and that of the hip or spine is not sufficient for accurate prediction of bone mineral content of the femoral neck o r spine, but one can, on the basis of the relationship, assign any individual to o n e / o f two broad classes - - that is, osteopenic or nonosteopenic. In a previous paper, (Pogi'und 1979) we investigated the relationship o f osteoporosis of the spine and hand using radiological criteria. We concluded that if osteoporosis of the hand is detected, it is very likely that osteoporosis o f the spine will be present. One the contrary, however, the absence of measurable osteoporosis of the hand did not exclude the p6ssibility of osteoporosis of the spine but made its presence much less likely. On the above basis, therefore, we feel that the radiological assessment o f osteoporosis of the hand provides a simple, rapid and highly satisfactory screening technique to be used before embarking on a battery of roentgenological and other more complex investigations in the suspect individual. ACKNOWLEDGEMENT This study was supported by foreign research agreement Nos. 1-AM-3-2204 and BSS-ACP-1S-1 Department of Health, Education and Welfare, Public Health Service National Institutes of Health, United States Government. 46
The Hand-- Volume 13
No. 1
1981
A Simple Radiological Screening Method for Assessment of Osteoporosis H. Pogrund, M. Makin, G. Robin, J. Menczel, M. Rousso and R. Steinberg
REFERENCES GOLDSMITH, N. F., JOHNSTON, J. O., URY, H., VOSE, G. and COLBERT, C. (1971) Bone Mineral Estimation in Normal and Osteoporotic Women. A Comparability Trial of Four Methods and Seven Bone Sites. The Journal of Bone and Joint Surgery, 53A: 83-100. HALL, M. C. (1961) The Trabecular Patterns Of The Neck Of The Femur With Particular Reference To Changes In Osteoporosis. The Canadian Medical Association Journal, 85:1141-1144. HELELA, T., TELKKA, A. and VIRTAMA, P. (1969) Bone Pattern of the Femoral Neck as a Measure Of Bone Density And Susceptibility To Hip Fractures. Annals of Clinical Research, 1: 85-87. HORSMAN, A. L., BULUSU, L., BENTLY, H. B. and NORDIN, B.E.C. (1970) Internal Relationships Between Skeletal Parameters in Twenty Three Male Skeletons. ed. Cameron, J. R. Proceedings of Bone Measurement Conference. USA. AEC Division of Technical Information. AEC Conf. - 700515. MAZESS, R. B. (1968) Estimation of bone and skeletal weight by the direct photon absorptiometric method. American Journal of Physical Anthropology, 29: 133. NAOR, E., DI SEGNI, V., ROBIN, G., MAKIN, M. and MENCZEL, J. (1971) Intra-observer Variability in the Determination of the Metacarpal Cortical Index. The British Journal of Radiology, 45; 213-217. POGRUND, H., MAKIN, M., ROBIN, G., MENCZEL, J. and STEINBERG, R. (1979) Osteoporosis of the Spine, Pelvis and Hand. A Comparative Study in a Femoral Neck Fracture Series. Clinical Orthopaedics and Related Research. 139: 156-163. SINGH, M., NAGRATH, A. R. and MAINI, P. S. (1970) Changes in Trabecular Pattern of the Upper End of the Femur as an Index of Osteoporosis. The Journal of Bone and Joint Surgery, 53-A: 457-467. SMITH, R. W. Jr. and RIZEK, J. (1966) Epidemiological Studies of Osteoporosis in Women of Puerto Rico and South Eastern Michigan with Special Reference to Age, Race, National Origin and to Other Related or Associated Findings. Clinical Orthopaedic and Related Research, 45: 31-48. TROTTER, M., BROMAN, G. E. and PETERSON, R. R. (1960) Densities of Bones of White and Negro Skeletons. The Journal of Bone Joint Surgery, 42-A: 50-58. WILSON, C. R. (1977) Bone-Mineral Content of the Femoral Neck and Spine versus the Radius or Ulna. The Journal of Bone Joint Surgery, 59-A: 665-669.
The Hand-- Volume 13
No. 1
1981
47