299
J. Anat. (1977), 124, 2, pp. 299-304 Printed in Great Britain
Diaphysial nutrient foramina in human metacarpals and metatarsals S. M. PATAKE* AND V. R. MYSOREKARt
*Department of Anatomy, V.M. Medical College, Solapur, Maharashtra State, India, and t Department of Anatomy, Armed Forces Medical College, Pune-1, Maharashtra State, India
(Accepted 1 August 1976) INTRODUCTION
The nutrient artery is a principal source of blood to a long bone and is particularly important during its active growth period. Havers (1691) described the directions of the nutrient canals in the long bones of various mammals. Berard (1835) was the first to correlate the direction of the nutrient canal with the mode of ossification and growth of the bone. Clark (1965) stated that greater longitudinal growth at the growing end of a bone resulted in the deflexion of the nutrient artery so that its entrance, which is initially at right angles to the shaft, becomes oblique, the obliquity being directed towards the non-growing end of the bone. The directions of the nutrient canals are remarkably constant. As every medical student knows, they seek the elbow and flee from the knee! Numerous workers have studied the nutrient foramina in long bones. Hughes (1952) has stated that anomalous canals are common in the femur, rare in the radius and very rare in other bones. However, Mysorekar (1967), who studied human long bones, found anomalously directed canals only in the fibula. He attributed this to the peculiar ossification pattern in that bone. The metacarpals and metatarsals are miniature or 'short' long bones, but are peculiar in having, as a rule, an epiphysis at one end only. The nutrient foramina of metacarpals and metatarsals have been studied by very few workers. Singh (1959, 1960), while studying variations in the articular facets of these bones, made some observations on their nutrient foramina. The present studies were undertaken to see, among otJVr things, whether the nutrient foramina in the metacarpals and metatarsals obey the general rule, i.e. directed away from the growing end. MATERIALS AND METHODS
Unknown series. 728 metacarpals (MC) and 691 metatarsals (MT) of unknown sex from the collection in the Anatomy Departments of the Miraj Medical College, Miraj, and the Armed Forces Medical College, Poona (Pune) were studied. The bones were preserved in the departments. Grossly pathological specimens were rejected. Only diaphysial nutrient foramina were studied. Known series. 120 metacarpals and 120 metatarsals from 12 cadavers of known sex were collected separately. They were cleaned of soft tissues, bleached in hydrogen peroxide and dried. The following observations were made on the nutrient foramina:
300
S. M. PATAKE AND V. R. MYSOREKAR
Table 1. Number offoramina No. of bones examined Name of bone
lMC II MC III MC IV MC V MC I MT II MT III MT IV MT VMT
, Right 90 93 81 84 79 99 69 79 80 71
Left
No. of foramina (figures give the number of bones) _ , _ __ _ 0 1 2
81 94 88 80 78 89
16 11 11 5 4 11
78
16
84 82 80
14 12 11
142 167 157 157 147 164 129 145 148 136
13 9 1 2 6 13 2 4 2 4
Total number of foramina 168 185 159 161 159 190 133 153 152 144
Number. The nutrient foramina were distinguished by the presence of a well marked groove leading to the foramen, and by a well marked, often slightly raised, edge of the foramen at the commencement of the canal. In doubtful cases a dissecting microscope was used to locate the foramen. When there were multiple foramina their sizes were visually compared, the larger one being designated as the dominant one. Position. The length of the bone (L) was measured by means of a sliding caliper. The distance of the foramen from the base was measured by means of a divider read on a scale graduated in millimetres. This distance is 'D'. The Foraminal Index (F.I.) was calculated according to Hughes' formula
F.I. =
D-x 100.
The position of the foramen in relation to the surfaces of the bone and its distance from the palmar or plantar ridge were noted. Direction of the canal. In cases of doubt a fine stiff wire was passed through the foramen to confirm its direction. Symmetry of the foramina. This was ascertainable only in the known series. The degree of symmetry was assessed as: (i) complete, when the number of foranina was the same on both the sides and their locations were similar, the difference between the two sides not exceeding 5 mm lengthwise and 2 mm circunVerentially; (ii) partial, when the number of foramina and their locations were similar but the difference exceeded 5 mm lengthwise and 2 mm circumferentially; and (iii) no symmetry, when the number of foramina was dissimilar. OBSERVATIONS
Except for the observations on the symmetry of the foramina, all other observations belonging to the known and unknown series were pooled. Number offoramina. The findings are analysed in Table 1. Position of theforamina. The findings are analysed in Table 2. Table 3 analyses the position of the foramina along the length of the bones, i.e. in the upper, middle or lower third, as seen from the foraminal indices. Analysis of the cases of bones showing double nutrient foramina is given in Table 4.
Nutrient foramina in metacarpals and metatarsals
301
Table 2. Position of the nutrient foramina Surface relation of foramina Name of bone
_ Number examined
A
A
M
I MC 171 144 IIMC 187 105 III MC 169 31 IV MC 164 25 V MC 157 4 IMT 188 8 II MT 147 26 IIIMT 163 49 IV MT 162 84 V MT 129 151 M, medial surface; L, lateral surface (plantar surface in ridge.
L
PR
9 55 103 123 147 162 105 96 67 1
15 25 25 13 8 20 2
Total number of foramina 163 185 159 161 159 190 133 153 152 144
8 1 14
case of the Vth MT); PR, palmar or plantar
Table 3. Position of the foramina in relation to the length of the bones Name of bone
Total Number of foramina in no. of A r forP M D amina
Range of F.i.
I MC 1 139 28 40 42-40-00 168 II MC 9 175 1 185 28-30-69-36 III MC 17 141 1 159 29 41-76-60 IV MC 8 151 2 161 30-20-78-40 V MC 3 156 0 159 31-70-6304 I MT 4 175 11 190 30-50-81-66 II MT 5 128 0 133 25-4 -55-55 III MT 4 149 0 153 31-40-59 1 IV MT 0 152 0 152 3640-62-91 V MT 0 143 1 144 37-3 -71-73 P, M. and D denote, respectively, the proximal, middle and distal Index.
Mean
S.D.
S.E.
59-43 46-06 40 83 43 04 45-91 5205 44 30 44-21
7 55 745 6-53
0-58 0-53 0-52 0-59 0-48
7-49 6-03 10-24 6 15 5-85 5-59 5 45
0-74
0-53 0-47 46-96 0-45 53-12 0-45 third of the bone. F.I., Foraminal
Observations on the symmetry of the nutrient foramina in the known series is analysed in Table 5. DISCUSSION
It is evident that most metacarpals and metatarsals have one nutrient foramen situated in the middle third of the bone. Singh (1960) found two nutrient foramina occurring more commonly in the metatarsals. Also, he found two foramina most commonly in the first and fifth metatarsals and the second metacarpal. However, in the present series two foramina were seen most frequently in the first metacarpal and first metatarsal. Absence of nutrient foramina in the long bones is well known (Liitken, 1950; Mysorekar, 1967). McGregor & DuPlessis (1969), in discussing the blood supply of short long bones, state that after cessation of growth the periosteal vessels take a much larger part in the blood supply of the bone and the nutrient artery becomes relatively unimportant. In cases where the nutrient foramen is absent, it is therefore 20
ANA 124
302
S. M. PATAKE AND V. R. MYSOREKAR
Table 4. Analysis of cases showing double nutrient foramina
Bone
No. showNo. of ing bones double studied foramina
No. with
equal sized foramina
Second foramen on
Dominant foramen on _ ____A M L PR
M
L
PR
3 8 I1 I (M+L) I MC 171 13 1 11 2 7 II MC 187 9 6 2 1 1 1 1 169 III MC 164 2 1 1 1 1 IV MC 157 6 3 3 VMC 6 188 13 1 (L+L) 1 7 4 2 10 I MT 2 1 2 II MT 147 1 4 1 2 2 3 III MT 163 2 1 (M+M) 1 162 IV MT 1 2 151 4 4 1 1 VMT M, Medial surface; L, Lateral surface (plantar surface in case of the Vth MT); PR, Palmar or plantar ridge; M+L means that one foramen was on the medial surface and the other on the lateral surface and so on.
Table 5. Symmetry of the foramina. Figures give the percentages Bone I MC 11 MC III MC IV MC V MC I MT II MT III MT IV MT V MT
Partial
Complete
No symmetry
25 8-3 8-3 16 7 41-7
58-3 33-3 66-7 66-7 75 33-3
41-7 41-7
8-3 8-3 16-6
667 66-7 41-7 41-7
25 25 8-3 25 33-3 25 50 41-7
likely that the periosteal vessels are entirely responsible for the blood supply of the bone. The number of foramina does not seem to have any significant relation to the length of the bone. Wood Jones (1946) mentions that even phalanges may have two nutrient foramina. Likewise, the number of foramina may not have any relation to the number of ossification centres, because the femur, with one primary centre, may have multiple foramina, whereas the clavicle, with two primary centres, has generally only one foramen. In textbooks the location of the nutrient foramen in the metacarpals has been described as on the medial side of the first and second and on the lateral sides of the remaining ones. Terry & Trotter (1953) described the origin of the nutrient artery to the medial side of the first metacarpal as from the princeps pollicis, that to the medial side of the second as from the second palmar metacarpal artery and those to the lateral sides of the remaining ones as from the second, third and fourth palmar metacarpal arteries. The nutrient artery located on the lateral surface of the first metacarpal could arise from the muscular branch to the opponens pollicis, that to the lateral surface of the second from the radialis indicis, those to the medial sides of the third and fourth from the palmar metacarpal arteries and that to the medial side of the fifth from the muscular branch to the opponens digiti minimi. In those
Nutrient foramina in metacarpals and metatarsals
303
cases where two nutrient foramina are located on the same surface it is likely that the nutrient arteries arise from the same source, whereas, when the foramina are located on different surfaces the source of the arteries is likely to be different. Murakami (1969) proposed a different nomenclature, wherein arteries running along the metacarpals alone were called palmar metacarpal arteries and those descending between the metacarpals were designated intermetacarpal arteries, which could lie either superficial or deep to the palmar interosseous muscles. According to Wood Jones (1946), the nutrient foramina of the first and second metatarsals, and usually of the third and fourth, are located on their lateral surfaces, whereas that of the fifth is on the medial surface. This pattern is almost the reverse of that found in the metacarpals. During the rotation of the limbs in embryonic development the corresponding surfaces of the metacarpals and metatarsals become reversed. If this concept is accepted the distribution of the nutrient foramina in the metatarsals can be said to be very similar to that of the metacarpals. In the present series, in the fourth metatarsal, foramina were more commonly encountered on the medial surface. These observations are in agreement with those of Singh (1960). Unfortunately, reports about the sources of the nutrient arteries in the metatarsals are not available. As observed from the known series, there is a good deal of bilateral symmetry in the nutrient foramina. According to Schwalbe (1876) the growth at the two ends of a long bone before the appearance of the epiphyses is equal. Hence, the nutrient canal before birth should be directed horizontally. Anseroff (1937), however, found considerable modification in the direction of the canal before birth. Brookes (1963) found, in the miniature long bones, that in the later part of the fetal period more growth occurred at the end that would develop the epiphysis. Roche (1965) demonstrated radiologically that longitudinal growth at the non-epiphysial end of these bones accounts for only 20-7 % to 30-2 % of the total increase in length. Many theories have been put forward to account for the generally constant direction of the canals, and also the anomalously directed ones. Among these are the 'periosteal slip' theory of Schwalbe (1876) and the vascular theory of Hughes (1952). Lacroix (1951) suggested that asymmetrical muscular development could modify the traction forces acting on the periosteum by the growing ends of the bone to a degree that is capable of modifying or even reversing the direction of the nutrient artery's entry into the diaphysis. In the present series the direction of the foramen was always away from the growing end, thus favouring the growing end theory. Typically, epiphyses appear for the base of the first metacarpal or metatarsal, and for the heads in the remaining metacarpals or metatarsals. However, additional epiphyses have been described for the head of the first metacarpal, base of the second metacarpal, and, rarely, for the bases of the other metacarpals. Similarly, epiphyses have been described for the head of the first metatarsal, while the epiphyses normally appearing in the heads of the other metatarsals may be replaced by epiphyses in their bases. It would be most interesting to study the direction of the nutrient foramina in these abnormal cases, either in the living or in the dead. Unfortunately, in fully ossified bones it is almost impossible to make out whether epiphyses had at one time been present.
20-2
304
S. M. PATAKE AND V. R. MYSOREKAR SUMMARY
728 metacarpals and 691 metatarsals of unknown sex, and 120 metacarpals and metatarsals, each of known sex, were studied for the number, position, direction and symmetry of the diaphysial nutrient foramina. It was found that, in general, these bones had one nutrient foramen which was situated in the middle third of the shaft (over 90 %). Few bones had no foramina and some had two. In the first and second metacarpals the foramina were mostly situated on the medial surface, and in the other metacarpals mostly on the lateral surface; whereas in the first three metatarsals the foramina were mostly situated on the lateral surface and in the remaining metatarsals mostly on the medial surface. There was a good deal of bilateral symmetry in the foramina. Without any exception, the foramina were directed away from the growing end. The various theories put forward to account for the direction of the nutrient foramina have been considered. The findings favour the 'growing-end' theory. Some of the data in the present paper were used by one of us (SMP) in preparing a dissertation submitted for the postgraduate degree in Anatomy of the Shivaji University, and the authors are grateful to the University for permitting the use of these records. The permission granted by the Principal, Miraj Medical College, Miraj, for the publishing of this paper is gratefully acknowledged. REFERENCES
ANSEROFF, N. J. (1937). Zeitschrift fur Anatomie und Entwicklungsgeschichte 106, 193-208. BERARD, A. (1835). Archives generale de Medicine. II Series 7, 176-183. BROOKES, M. (1963). Cortical vascularization and growth in foetal tubular bones. Journal of Anatomy 97, 597-609. HAVERS, CL. (1691). Osteologia nova. London. HUGHES, H. (1952). The factors determining the direction of the canal for the nutrient artery in the long bones of mammals and birds. Acta anatomica 15, 261-286. LACROIX, P. (1951). The Organization of Bones. London: Churchill. LE GROS CLARK, W. E. (1965). The Tissues of the Body, p. 117. Oxford: Clarendon Press. LUTKEN, P. (1950). Investigation into the position of the nutrient foramina and the direction of the vessel canals in the shafts of the humerus and femur in man. Acta anatomica 9, 57-68. MCGREGOR, A. L. & DUPLEsSIs, D. J. (1969). A Synopsis of Surgical Anatomy, p. 246. Bombay: K. M. Varghese Company. MURAKAMI, T. (1969). On the position and course of the deep palmar arteries with special reference to the so called palmar metacarpal arteries. Okajimas folia anatomica japonica 46, 177-199. MYSOREKAR, V. R. (1967). Diaphysial nutrient foramina in human long bones. Journal of Anatomy 101, 813-822. ROCHE, A. F. (1965). The sites of elongation of human metacarpals and metatarsals. Acta anatomica 61, 193-202. SCHWALBE, G. (1876). Zeitschrift fur Anatomie und Entwicklungsgeschichte 1, 307-352. SINGH, I. (1959). Variations in the metacarpal bones. Journal of Anatomy 93, 262-267. SINGH, I. (1960). Variations in the metatarsal bones. Journal of Anatomy 94, 345-350. TERRY, R. J. & TROTTER, M. (1953). In Morris' Human Anatomy, (ed. J. P. Schaeffer), pp. 234-237. London: McGraw-Hill Book Company. WOOD JoNEs, F. (1946). Buchanan's Manual of Anatomy, pp. 310, 367. London: Bailliere, Tindall and Cox.
J. Anat. (1977), 124, 2, pp. 299-304 Printed in Great Britain
Diaphysial nutrient foramina in human metacarpals and metatarsals S. M. PATAKE* AND V. R. MYSOREKARt
*Department of Anatomy, V.M. Medical College, Solapur, Maharashtra State, India, and t Department of Anatomy, Armed Forces Medical College, Pune-1, Maharashtra State, India
(Accepted 1 August 1976) INTRODUCTION
The nutrient artery is a principal source of blood to a long bone and is particularly important during its active growth period. Havers (1691) described the directions of the nutrient canals in the long bones of various mammals. Berard (1835) was the first to correlate the direction of the nutrient canal with the mode of ossification and growth of the bone. Clark (1965) stated that greater longitudinal growth at the growing end of a bone resulted in the deflexion of the nutrient artery so that its entrance, which is initially at right angles to the shaft, becomes oblique, the obliquity being directed towards the non-growing end of the bone. The directions of the nutrient canals are remarkably constant. As every medical student knows, they seek the elbow and flee from the knee! Numerous workers have studied the nutrient foramina in long bones. Hughes (1952) has stated that anomalous canals are common in the femur, rare in the radius and very rare in other bones. However, Mysorekar (1967), who studied human long bones, found anomalously directed canals only in the fibula. He attributed this to the peculiar ossification pattern in that bone. The metacarpals and metatarsals are miniature or 'short' long bones, but are peculiar in having, as a rule, an epiphysis at one end only. The nutrient foramina of metacarpals and metatarsals have been studied by very few workers. Singh (1959, 1960), while studying variations in the articular facets of these bones, made some observations on their nutrient foramina. The present studies were undertaken to see, among otJVr things, whether the nutrient foramina in the metacarpals and metatarsals obey the general rule, i.e. directed away from the growing end. MATERIALS AND METHODS
Unknown series. 728 metacarpals (MC) and 691 metatarsals (MT) of unknown sex from the collection in the Anatomy Departments of the Miraj Medical College, Miraj, and the Armed Forces Medical College, Poona (Pune) were studied. The bones were preserved in the departments. Grossly pathological specimens were rejected. Only diaphysial nutrient foramina were studied. Known series. 120 metacarpals and 120 metatarsals from 12 cadavers of known sex were collected separately. They were cleaned of soft tissues, bleached in hydrogen peroxide and dried. The following observations were made on the nutrient foramina:
300
S. M. PATAKE AND V. R. MYSOREKAR
Table 1. Number offoramina No. of bones examined Name of bone
lMC II MC III MC IV MC V MC I MT II MT III MT IV MT VMT
, Right 90 93 81 84 79 99 69 79 80 71
Left
No. of foramina (figures give the number of bones) _ , _ __ _ 0 1 2
81 94 88 80 78 89
16 11 11 5 4 11
78
16
84 82 80
14 12 11
142 167 157 157 147 164 129 145 148 136
13 9 1 2 6 13 2 4 2 4
Total number of foramina 168 185 159 161 159 190 133 153 152 144
Number. The nutrient foramina were distinguished by the presence of a well marked groove leading to the foramen, and by a well marked, often slightly raised, edge of the foramen at the commencement of the canal. In doubtful cases a dissecting microscope was used to locate the foramen. When there were multiple foramina their sizes were visually compared, the larger one being designated as the dominant one. Position. The length of the bone (L) was measured by means of a sliding caliper. The distance of the foramen from the base was measured by means of a divider read on a scale graduated in millimetres. This distance is 'D'. The Foraminal Index (F.I.) was calculated according to Hughes' formula
F.I. =
D-x 100.
The position of the foramen in relation to the surfaces of the bone and its distance from the palmar or plantar ridge were noted. Direction of the canal. In cases of doubt a fine stiff wire was passed through the foramen to confirm its direction. Symmetry of the foramina. This was ascertainable only in the known series. The degree of symmetry was assessed as: (i) complete, when the number of foranina was the same on both the sides and their locations were similar, the difference between the two sides not exceeding 5 mm lengthwise and 2 mm circunVerentially; (ii) partial, when the number of foramina and their locations were similar but the difference exceeded 5 mm lengthwise and 2 mm circumferentially; and (iii) no symmetry, when the number of foramina was dissimilar. OBSERVATIONS
Except for the observations on the symmetry of the foramina, all other observations belonging to the known and unknown series were pooled. Number offoramina. The findings are analysed in Table 1. Position of theforamina. The findings are analysed in Table 2. Table 3 analyses the position of the foramina along the length of the bones, i.e. in the upper, middle or lower third, as seen from the foraminal indices. Analysis of the cases of bones showing double nutrient foramina is given in Table 4.
Nutrient foramina in metacarpals and metatarsals
301
Table 2. Position of the nutrient foramina Surface relation of foramina Name of bone
_ Number examined
A
A
M
I MC 171 144 IIMC 187 105 III MC 169 31 IV MC 164 25 V MC 157 4 IMT 188 8 II MT 147 26 IIIMT 163 49 IV MT 162 84 V MT 129 151 M, medial surface; L, lateral surface (plantar surface in ridge.
L
PR
9 55 103 123 147 162 105 96 67 1
15 25 25 13 8 20 2
Total number of foramina 163 185 159 161 159 190 133 153 152 144
8 1 14
case of the Vth MT); PR, palmar or plantar
Table 3. Position of the foramina in relation to the length of the bones Name of bone
Total Number of foramina in no. of A r forP M D amina
Range of F.i.
I MC 1 139 28 40 42-40-00 168 II MC 9 175 1 185 28-30-69-36 III MC 17 141 1 159 29 41-76-60 IV MC 8 151 2 161 30-20-78-40 V MC 3 156 0 159 31-70-6304 I MT 4 175 11 190 30-50-81-66 II MT 5 128 0 133 25-4 -55-55 III MT 4 149 0 153 31-40-59 1 IV MT 0 152 0 152 3640-62-91 V MT 0 143 1 144 37-3 -71-73 P, M. and D denote, respectively, the proximal, middle and distal Index.
Mean
S.D.
S.E.
59-43 46-06 40 83 43 04 45-91 5205 44 30 44-21
7 55 745 6-53
0-58 0-53 0-52 0-59 0-48
7-49 6-03 10-24 6 15 5-85 5-59 5 45
0-74
0-53 0-47 46-96 0-45 53-12 0-45 third of the bone. F.I., Foraminal
Observations on the symmetry of the nutrient foramina in the known series is analysed in Table 5. DISCUSSION
It is evident that most metacarpals and metatarsals have one nutrient foramen situated in the middle third of the bone. Singh (1960) found two nutrient foramina occurring more commonly in the metatarsals. Also, he found two foramina most commonly in the first and fifth metatarsals and the second metacarpal. However, in the present series two foramina were seen most frequently in the first metacarpal and first metatarsal. Absence of nutrient foramina in the long bones is well known (Liitken, 1950; Mysorekar, 1967). McGregor & DuPlessis (1969), in discussing the blood supply of short long bones, state that after cessation of growth the periosteal vessels take a much larger part in the blood supply of the bone and the nutrient artery becomes relatively unimportant. In cases where the nutrient foramen is absent, it is therefore 20
ANA 124
302
S. M. PATAKE AND V. R. MYSOREKAR
Table 4. Analysis of cases showing double nutrient foramina
Bone
No. showNo. of ing bones double studied foramina
No. with
equal sized foramina
Second foramen on
Dominant foramen on _ ____A M L PR
M
L
PR
3 8 I1 I (M+L) I MC 171 13 1 11 2 7 II MC 187 9 6 2 1 1 1 1 169 III MC 164 2 1 1 1 1 IV MC 157 6 3 3 VMC 6 188 13 1 (L+L) 1 7 4 2 10 I MT 2 1 2 II MT 147 1 4 1 2 2 3 III MT 163 2 1 (M+M) 1 162 IV MT 1 2 151 4 4 1 1 VMT M, Medial surface; L, Lateral surface (plantar surface in case of the Vth MT); PR, Palmar or plantar ridge; M+L means that one foramen was on the medial surface and the other on the lateral surface and so on.
Table 5. Symmetry of the foramina. Figures give the percentages Bone I MC 11 MC III MC IV MC V MC I MT II MT III MT IV MT V MT
Partial
Complete
No symmetry
25 8-3 8-3 16 7 41-7
58-3 33-3 66-7 66-7 75 33-3
41-7 41-7
8-3 8-3 16-6
667 66-7 41-7 41-7
25 25 8-3 25 33-3 25 50 41-7
likely that the periosteal vessels are entirely responsible for the blood supply of the bone. The number of foramina does not seem to have any significant relation to the length of the bone. Wood Jones (1946) mentions that even phalanges may have two nutrient foramina. Likewise, the number of foramina may not have any relation to the number of ossification centres, because the femur, with one primary centre, may have multiple foramina, whereas the clavicle, with two primary centres, has generally only one foramen. In textbooks the location of the nutrient foramen in the metacarpals has been described as on the medial side of the first and second and on the lateral sides of the remaining ones. Terry & Trotter (1953) described the origin of the nutrient artery to the medial side of the first metacarpal as from the princeps pollicis, that to the medial side of the second as from the second palmar metacarpal artery and those to the lateral sides of the remaining ones as from the second, third and fourth palmar metacarpal arteries. The nutrient artery located on the lateral surface of the first metacarpal could arise from the muscular branch to the opponens pollicis, that to the lateral surface of the second from the radialis indicis, those to the medial sides of the third and fourth from the palmar metacarpal arteries and that to the medial side of the fifth from the muscular branch to the opponens digiti minimi. In those
Nutrient foramina in metacarpals and metatarsals
303
cases where two nutrient foramina are located on the same surface it is likely that the nutrient arteries arise from the same source, whereas, when the foramina are located on different surfaces the source of the arteries is likely to be different. Murakami (1969) proposed a different nomenclature, wherein arteries running along the metacarpals alone were called palmar metacarpal arteries and those descending between the metacarpals were designated intermetacarpal arteries, which could lie either superficial or deep to the palmar interosseous muscles. According to Wood Jones (1946), the nutrient foramina of the first and second metatarsals, and usually of the third and fourth, are located on their lateral surfaces, whereas that of the fifth is on the medial surface. This pattern is almost the reverse of that found in the metacarpals. During the rotation of the limbs in embryonic development the corresponding surfaces of the metacarpals and metatarsals become reversed. If this concept is accepted the distribution of the nutrient foramina in the metatarsals can be said to be very similar to that of the metacarpals. In the present series, in the fourth metatarsal, foramina were more commonly encountered on the medial surface. These observations are in agreement with those of Singh (1960). Unfortunately, reports about the sources of the nutrient arteries in the metatarsals are not available. As observed from the known series, there is a good deal of bilateral symmetry in the nutrient foramina. According to Schwalbe (1876) the growth at the two ends of a long bone before the appearance of the epiphyses is equal. Hence, the nutrient canal before birth should be directed horizontally. Anseroff (1937), however, found considerable modification in the direction of the canal before birth. Brookes (1963) found, in the miniature long bones, that in the later part of the fetal period more growth occurred at the end that would develop the epiphysis. Roche (1965) demonstrated radiologically that longitudinal growth at the non-epiphysial end of these bones accounts for only 20-7 % to 30-2 % of the total increase in length. Many theories have been put forward to account for the generally constant direction of the canals, and also the anomalously directed ones. Among these are the 'periosteal slip' theory of Schwalbe (1876) and the vascular theory of Hughes (1952). Lacroix (1951) suggested that asymmetrical muscular development could modify the traction forces acting on the periosteum by the growing ends of the bone to a degree that is capable of modifying or even reversing the direction of the nutrient artery's entry into the diaphysis. In the present series the direction of the foramen was always away from the growing end, thus favouring the growing end theory. Typically, epiphyses appear for the base of the first metacarpal or metatarsal, and for the heads in the remaining metacarpals or metatarsals. However, additional epiphyses have been described for the head of the first metacarpal, base of the second metacarpal, and, rarely, for the bases of the other metacarpals. Similarly, epiphyses have been described for the head of the first metatarsal, while the epiphyses normally appearing in the heads of the other metatarsals may be replaced by epiphyses in their bases. It would be most interesting to study the direction of the nutrient foramina in these abnormal cases, either in the living or in the dead. Unfortunately, in fully ossified bones it is almost impossible to make out whether epiphyses had at one time been present.
20-2
304
S. M. PATAKE AND V. R. MYSOREKAR SUMMARY
728 metacarpals and 691 metatarsals of unknown sex, and 120 metacarpals and metatarsals, each of known sex, were studied for the number, position, direction and symmetry of the diaphysial nutrient foramina. It was found that, in general, these bones had one nutrient foramen which was situated in the middle third of the shaft (over 90 %). Few bones had no foramina and some had two. In the first and second metacarpals the foramina were mostly situated on the medial surface, and in the other metacarpals mostly on the lateral surface; whereas in the first three metatarsals the foramina were mostly situated on the lateral surface and in the remaining metatarsals mostly on the medial surface. There was a good deal of bilateral symmetry in the foramina. Without any exception, the foramina were directed away from the growing end. The various theories put forward to account for the direction of the nutrient foramina have been considered. The findings favour the 'growing-end' theory. Some of the data in the present paper were used by one of us (SMP) in preparing a dissertation submitted for the postgraduate degree in Anatomy of the Shivaji University, and the authors are grateful to the University for permitting the use of these records. The permission granted by the Principal, Miraj Medical College, Miraj, for the publishing of this paper is gratefully acknowledged. REFERENCES
ANSEROFF, N. J. (1937). Zeitschrift fur Anatomie und Entwicklungsgeschichte 106, 193-208. BERARD, A. (1835). Archives generale de Medicine. II Series 7, 176-183. BROOKES, M. (1963). Cortical vascularization and growth in foetal tubular bones. Journal of Anatomy 97, 597-609. HAVERS, CL. (1691). Osteologia nova. London. HUGHES, H. (1952). The factors determining the direction of the canal for the nutrient artery in the long bones of mammals and birds. Acta anatomica 15, 261-286. LACROIX, P. (1951). The Organization of Bones. London: Churchill. LE GROS CLARK, W. E. (1965). The Tissues of the Body, p. 117. Oxford: Clarendon Press. LUTKEN, P. (1950). Investigation into the position of the nutrient foramina and the direction of the vessel canals in the shafts of the humerus and femur in man. Acta anatomica 9, 57-68. MCGREGOR, A. L. & DUPLEsSIs, D. J. (1969). A Synopsis of Surgical Anatomy, p. 246. Bombay: K. M. Varghese Company. MURAKAMI, T. (1969). On the position and course of the deep palmar arteries with special reference to the so called palmar metacarpal arteries. Okajimas folia anatomica japonica 46, 177-199. MYSOREKAR, V. R. (1967). Diaphysial nutrient foramina in human long bones. Journal of Anatomy 101, 813-822. ROCHE, A. F. (1965). The sites of elongation of human metacarpals and metatarsals. Acta anatomica 61, 193-202. SCHWALBE, G. (1876). Zeitschrift fur Anatomie und Entwicklungsgeschichte 1, 307-352. SINGH, I. (1959). Variations in the metacarpal bones. Journal of Anatomy 93, 262-267. SINGH, I. (1960). Variations in the metatarsal bones. Journal of Anatomy 94, 345-350. TERRY, R. J. & TROTTER, M. (1953). In Morris' Human Anatomy, (ed. J. P. Schaeffer), pp. 234-237. London: McGraw-Hill Book Company. WOOD JoNEs, F. (1946). Buchanan's Manual of Anatomy, pp. 310, 367. London: Bailliere, Tindall and Cox.
