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Skeletal maturation in the hand A study of development in East African children
135 rI'RANSACTIONS OF THE ROYAL SOCIETY OF TROPICAL MEDICINE AND HYGIENE Vol. 46. No. 2. March, 1952.
COMMUNICATIONS S K E L E T A L M A T U R A T I O N IN T H E H A N D : A STUDY OF D E V E L O P M E N T IN EAST AFRICAN CHILDREN. BY
D. H. MACKAY, M.R.C.S., L.R.C.P., D.P.H., D.T.M. & H.* Colonial Medical Service, Kenya.
In the progress of a child from birth to maturity chronological age affords an insufficient measure of assessing development, as children of equal age differ widely in their degree of physical development. Many methods have been devised of more accurately measuring progress. Among these, studies of heights and weights in relation to age, and the determination of intellectual attainment by intelligence tests have contributed knowledge on physical and mental development. As a further index of physical development the growth pattern of the skeletal framework of the body has been studied, and techniques have been devised, notably in America, of estimating skeletal maturation by radiography. These techniques have resulted in standards for the skeletal development of Caucasian children being laid down. No similar standards exist for any of the African peoples. In East Africa any attempt to relate physical development to age has been difficult or impossible owing to the absence generally of reliable statistics based on birth registration. Before making comparisons between the physical development of AfriCan and Caucasian children it seems essential that not only the rate, but the pattern, of their progress to maturity should be studied. I t was therefore considered that an investigation of skeletal maturation in African children, by contributing basic information as to the bodily framework on which their physical development was founded, would form a useful basis for making comparisons with children of other races. The account of the work that follows is of an attempt to study the pattern *My thanks are due to the Hon. Director of Medical Services, Kenya, for permission to submit this paper, to Professor G. MACDONALDfor considerable help and encouragement throughout the work, and to my wife for clerical assistance and practical help in gaining the confidence of the children during their examination. My thanks are also due to the Secretary of State for the Colonies, who, on the recommendation of the Colonial Medical Research Committee, contributed generously from research funds, provided under the Colonial Development and Welfare Acts, to the publication of the Figures that illustrate this paper.
1__36
SKELETAL MATURATION IN THE HAND IN AFRICAN CHILDREN
and rate of skeletal growth in the hand of children of one particular East African tribe, carried out with the object of formulating skeletal age standards for them. THE
POPULATION
STUDIED.
The Wadigo, a tribe of Bantu origin, occupy a strip of the East African coast extending from Mombasa in the north to Tanga in the south.. Halfway between Mombasa and the Tanganyika border is a thickly populated area called Msambweni which consists of a series of contiguous villages. i
l'q°'h;
!
,, ,
~ ~z='3i~'k"
I
Roughly indicates area inhabited by the Wadlgo.
The climate is tropical with an annual rainfall of over 45 inches, and ancylostomiasis and subtertian malaria are hyperendemic. Anaemia associated with ancylostomiasis is universal. The Wadigo of Msambweni cultivate some rice, but their staple diet is cassava. S o m e cattle are kept, but little milk is consumed, at any rate by children. Fishing forms one of the major occupations of the community, and seafish provide the most frequent source of animal protein. In 1927 the area received its first organized medical attention when a mass treatment and sanitation campaign against hookworm was carried out by MACLENNAN and PHILIP. Subsequently Msambweni was chosen as a site for a govern-
D. H . MACKAY
FIG. 1.
FIo. 2.
Chief Salim Mohamed, with the aid of the Birth Register, checking the children before examination.
Illustrating the position of the subject when radiographs were taken,
137
D. H. MACKAY
139
ment hospital and the centre of future medical activities. PHILIP remained as the first medical officer of health. One of his first acts was to persuade the people to accept a voluntary scheme for the registration of births and deaths. African Sanitary Assistants were trained, as part of their duties, to collect information as to births and deaths, and to enter it in a central register kept at the hospital. As the years went by, and the work of the hospital increased subsequent medical officers were unable to devote much attention to the scheme especially as it was felt that in the absence of any statutory compulsion many births and deaths were being unrecorded, and that statistics derived from those that were registered were therefore unreliable. Partial notification of births however has continued until the present day, the greater number of notifications being received from those villages nearest to the hospital. At the time this study started there thus existed an appreciable child population near to the hospital of ascertainable age. METHOD.
From the central register of births names of children born in the area in various years, together with the names of their parents, were abstracted. Lists were then given to the Sanitary Assistants who went out and endeavoured to trace the children on their lists. In many cases the children had died, or had moved away to another place, or for some other reason could not be traced, but there remained a substantial number appearing to answer to the particulars in the register. Careful checking was necessary, particularly as the name by which the child was registered was not always the name by which he was known in later years. Considerable help was given by the village elders, and by the Chief, who had previously been one of the original Sanitary Assistants engaged in the work of registration. Consent was then obtained from the parents for the child to attend the hospital on special mornings set aside for examinations. On arrival at the hospital further checking with the aid of the Chief and elders was necessary, as it was not uncommon for the parents to get muddled and bring the wrong children, or for a boy to send along a brother in his place. When a batch of children had been verified beyond reasonable doubt they were given tickets bearing their names and dates of birth, and kept under observation until they were examined in order to prevent exchange of tickets. Before being submitted to radiography measurements of height, sitting height, pelvic diameter and weight were made, and dental state recorded in detail. It is hoped that analysis of the data thus obtained will form the subject of a subsequent paper. Both hands were X-rayed, using a portable Victor X-Ray unit powered by a petrol electric generator. A standard tube length of 30 inches was maintained for all exposures. The film holder was placed on a table with the X-ray tube vertically above. Care was taken to place the subject so that the forearm was laid
140
SKELETAL M A T U R A T I O N I N THE HAND I N AFRICAN C H I L D R E N
flat on the table, the body of the child being caused to lean to one side in order to ensure that the lower end of the radius did not rotate about the ulna. Each. film was n u m b e r e d at the time of exposure by means of a metal device, the n u m b e r of the film corresponding with the serial n u m b e r on the card used for recording l~irth dates and body measurements. NUMBER OF CtIILDREN EXAMINED. T h e total n u m b e r of children examined was 1,360, m a d e up of 602 girls and 758 boys. T h e i r distribution by age and sex is given in T a b l e I below. TABLE 1. Number Of children examined by age and sex. Age.
Girls.
Boys,
Total.
0--
1234567891011121314151617-18
51 39 45 23 28 26 35 31 36 33 39 41 26 42 25 32 38 12
49 69 41 25 30 48 37 44 43 44 50 51 41 30 40 32 74 10
100 108 86 48 58 74 72 75 79 77 89 92 67 72 65 64 112 22
Total
602
,
I
758
1,360
METHOD OF ANALYSING THE DATA. I n an endeavour to record objectively the sum total of the variables relating to carpal bones and epiphyses in each X - r a y the following technique was evolved. Each pair of X - r a y films was inspected and the chronological age, and sex of the child, the presence of ossification centres of bones and epiphyses, and also certain readily recognisable features of some bones and epiphyses were then marked off on n u m b e r s allotted to t h e m on Findex ptmch cards. W h e r e development in one hand was greater than iaa the other, which occurred not infrequently in the younger age groups when new centres were appearing, the hand showing the greater degree of development was recorded. No attempt was m a d e to assess development b y measuring with a planimeter the areas of the shadows Of the carpal bones as was done by CARTER (1926) and FLORY (1936), as it was thought that such a
D. H. MACKAY
141
method, involving a time consuming and difficult technique, does not give results superior to that of a careful inspectional analysis. W h e n every film had been inspected and recorded the cards were sorted first into sexes, and then into age groups. As the children in each age group varied in chronological age throughout the whole range of 12 months the average age of each age group fell at 6 m o n t h s over the last birthday. For example, a child who had attained his 10th birthday but had not yet reached his l l t h would be placed in the group I0-11, and the average age of his group would be 10 years and 6 months. It will be important to bear this point in mind when comparisons are made later with FLORY'S studies (1936), as his subjects were all radiographed within a fortnight of their birthday, and thus a 10-year old by his standards is 6 months younger than a child in the 10-year group in this study. T h e cards for each age sex group w e r e then sorted for the frequency of occurrence of each characteristic recorded, and tabulated under headings as shown in T a b l e II. F r o m the data thus tabulated it was then possible to prepare charts showing the appearance of the carpal bones and epiphyses in each age sex group expressed as percentage present, and to estimate probable times of appearances. , TABLE II.
Chart showing characteristics recorded.
Sex : M . orF. Age : Number in Group : Capitatum : Hamatum : Triquetrum : Lunatum : Naviculare :
R a d i a l Epiphysis.
Ulnar Epiphysis.
Present : ,, and equal : ,, 5 ulnar beak : ,, ~ radial beak : Fusion started : Fusion complete :
Present : ,, and equal : ,, "d styloid : Fusion started : Fusion complete :
Metacarpals
I
II
III
IV
-V
I
II
III
IV
V
Muh. majus : Present : with horn : Fusion started : overlaps Met II : Fusion complete : Mult. minus : overlaps M. maius Hamatum overlaps Met. V :
Prox. Phalanges
Present : Fusion started :
Sesamoids : Fusion complet e : Development
Right greater than Left : Left greater than Right : Right and Left equal : Abnormalities :
142
SKELETAL MATURATION IN THE HAND IN AFRICAN CHILDREN ANALYSIS OF RESULTS.
The Appearance of the Carpal Bones. The capitatum and hamatum were invariably the first bones to appear, usually together. The radial epiphysis followed, and then successively triquetrum, lunatum and naviculare. Multangulum majus and minus next appeared, but the order in which naviculare and the multangulars appeared was subject to much variation. The ulnar epiphysis followed the multangular bones, and was in turn followed by the pisiforme. The sesamoid bones at the distal end of metacarpal I were the last to make their appearance.
Sex Differences in the Ossification of the Hand. There are sex differences in the times of appearance of centres of ossification. These are slight at first, but in each succeeding year girls become more advanced than boys, so that by the age of 9½ years the average girl is 1½ to 2 years skeletally more mature than the average boy. This sex difference is demonstrated in the tables and age standards which follow.
The Times of Appearance of the Carpal Bones. Table III which follows shows the appearance of the carpal bones, including the radial and ulnar epiphyses, of the boys and girls examined expressed as percentage present, while Table IV shows the results obtained by FLORY (1936), working with Chicago school children.
Comparison between Tables I H and IV. Inspection of Tables III and IV reveals that while the order of appearance of the carpal ossification centres is similar, the African children take longer from the time of first appearance of an ossification centre to reach a point where that centre is present in all hands. This increased variability becomes more marked as age progresses. It is also apparent from comparison of the two tables that the African children take longer to reach skeletal maturity in the hand than the Chicago children. The shift to the right of the figures in the table for African children becomes even more marked when it is remembered that in Table III figures refer to mean age at the ½ year over each birthday, while in Table IV they refer to percentages of centres present 6 months earlier on the birthday.
....
....
8esarnoids
epiphysis
Pisiforme
Ulnar
..
F M
0t
F M
I
0 0
0
0 0
0 0
0 0
0 0
18 12
51 41
85 52
i °
0 0
0 0
F M
F M
0 0
F M
..
0 0
F M
....
Navieulare
Mult. minus
2 3
F M
....
Lunatum
..
2O 14
F M
Triquetrum
Mult. majus
20 8
F M
Radial epiphysis
00 00
86 84
F M
••
Hamatum
00 00
88 92
F
....
.-
O-L
Sex.
0 0
0 0
0 0
ol
0
0 0
2 0~
24 12
69 46
96 76
2-
0 0
0 0
0 0
32 0
3~ 7
32 13
68 50
75 83
93 97
4-
0 0
0 0
12 0
46 17
50 25
46 23
69 62
O0 O0
96 O0
5-
23 16
74 54
60 59
0 0
0 0
45 16
94 52
97 52
0 0
8 0
72 44
94 84
97 84
94 86
00 98
Age
3 0
27 2
88 80
100 95
100 95
5 0
31 2
95 76
95 100
98
37 8
61 18
100 98
100 98
96
98
98
11-
46 5
73 17
100 93
100
100
100
100
12-
90 17
90 27
98 100
13-
92 30
96 55
100
14-
97 66
O0 81
15-
T h e a p p e a r a n c e of t h e carpal b o n e s of boys a n d girls e x p r e s s e d i n p e r c e n t a g e p r e s e n t .
Capitatum
Bone.
TABLE I I I .
90
90
17-18
t~
F.
..
Triquetrum
..
• °
Mult. minus
Ulnar epiphysis
..
..
M u l t . majus
Pisiforme
..
Naviculare
. . . .
..
Radial epiphysis
Lunatum
..
. . . .
I
M
F
M
F
F
F M
h
Sex.
0
o
°o
o
o o
0 0
0 0 0 0
0 0
0 0
0 0
0 8
20 22
0 0
0 0
78 34
96 98
0 0
8 2
o
0 0
0 0
4 0
0 0
32 18
52 50
O0 98
100
loo
100
/
0 0
0 0
15 4
18 4
12 4
50 36
79 57
100
3
0 0
0 0
40 22
53 14
30 17
80 64
100 92
4
0 0
6 7
;5 9
'4 ~3
;1 14
~1 ;4
',4
5
0 0
60 27
95 48
94 51
95 51
99 87
93
90 59
100 81
99 72
99 75
100 98
100
7
19 2
100 82
95
100 88
100 92
99
Age 8
50 6
98
100
96
99
100
9
79 22
100
99
97
99
10
96 28
100
100
100
11
100 66
12
95
13
99
14
99
15
T h e a p p e a r a n c e o f carpal bones for boys a n d girls e x p r e s s e d in p e r c e n t a g e p r e s e n t according to FLORY o n U n i v e r s i t y of Chicago L a b o r a t o r y school children.
Hamatum
Capitatum
Bone.
TABLE IV.
100
16
ra
w
z
2
t~
D.
H,
MACKAY
145
Probable Age of Appearance of Carpal Bones in Months. T h e probable age of appearance is considered to be the age at which 50 per cent. of the subjects showed a centre present. This point can be estimated by inspection of Table III. FLORY (1936) followed the same practice in estimating age of appearance in the Chicago school children. In Table V are set out the probable ages of appearance in months of the carpal centres in the Wadigo children, and FLORY'S estimates for the Chicago children. TABLE V. Probable age of appearance of carpal bones in months.
Bone. Capitatum . . . . Hamatum Radial epiphysis Triquetrum Lunatum . . . . Naviculare Mult. majus Mult. minus Ulnar epiphysis Pisiforme . . . .
.. .. ..
• .
.. .. .. .. • .
Wadigo Children
Chicago Children
Males.
Females.
Males
Females.
6 6 18 34 54 72 78 78 98 166
6 6 13 18 42 63 66 68 93 132
6 6 15 24 42 72 72 73 80 140
6 6 9 23 36 56 50 53 68 108
The Metacarpal and Phalangeal Epiphyses. Metacarpal epiphyses II to V start to appear in that order by about the 1st birthday in girls, and 9 months to a year later in boys. T h e epiphyseal centre for metacarpal I appears around the 2nd birthday in girls, and at about 3 years and 6 months in boys. T h e epiphyseal centres for the proximal phalanges, with the exception of the centre for phalanx I, appear in girls by the 1st birthday, and in boys by about the 2nd. Centres for the distal phalanges appear a little later. In Table VI are shown the percentage of these centres present at successive ages in the Wadigo children studied, and in Table VII are the results obtained by FLORY (1936) in the Chicago school children. It will be seen from these tables that in the case of the African children studied progress towards attaining 100 per cent. representation of metacarpal and phalangeal epiphyses is spread out over a much longer period of time, and evenually is reached at a much later age than in the American children•
146
SKELETAL
TABLE VI.
MATURATION
IN
THE
HAND
IN
AFRICAN
CHILDREN
T h e percentage of metacarpal and proximal phalangeal epiphyses present in Wadigo children at successive ages.
Age.
~piphyses.
Sex
o- ¸ 1-I~:13-
~
~- 6- 7- 8-~9-, 10-111-~12-J13-rl~-,,,,
r
Metacarpals
m__
__
' I
F M
0 0
1849 78 82 88 97100 0 0 60~ 63 77 89 98!9395
II
F M
12 0
III
F M
12 92 93i100 0 35 76 96 100
IV
F M
8 79 91 100 96 100 0 29 71 96 97 98 100
V
F M
6 69 91 100 96 100 0 1761 96 93 98 100
I
F M
100 0 21 73 91 93 , 0 0 5 56 70 94 100
II
F M
10 95 98 100 6 33 93 96 100
III
F M
16 100 8 44 93
IV
F M
14 97 98 100 6 32 85 96 100
V
F M
92 96 100 33 78 96 100
Proximal phalanges
96 100
6 6291 100 0 12 50 96
96i100 93 98 100
98 100
93
87100
D. H. MACKAY
TABLE V I I .
147
T h e p e r c e n t a g e of m e t a c a r p a l a n d p r o x i m a l p h a l a n g e a l e p i p h y s e s p r e s e n t in Chicago c h i l d r e n according to FLORY. Age. Epiphyses.
Sex. 2
3
4
I
Metacarpals F
18 0
80 25
100 93
! [
.
M
II
. . . . . .
F M
42 12
92 90
100 100
,
III
. . . . . .
F M
38 10
92 78
100 100
IV
. . . . . .
F M
28 6
92 78
100 100
V
. . . . . .
F M
24 0
92 65
100 100
I
.
.
.
.
.
! l
5
i
-
97
100
100 97
100
;
Proximal phalanges F
8
.
M
0
72 18
97 100
II
. . . . . .
F M
58 20
92 98
100 100
III
. . . . . .
F M
58 22
92 98
100 100
IV
. . . . . .
F M
58 20
92 95
100 100
V
. . . . . .
F M
36 2
92 88
100 100
I
.
.
.
.
.
148
SKELETAL M A T U R A T I O N I N THE HAND I N AFRICAN C H I L D R E N
Abnormalities. Various developmental anomalies were noted in the series. Pseudoepiphyses at the proximal end of metacarpal II occurred 25 times, and at the distal end of metacarpal I 16 times. The ulnar epiphysis presented a double centre of ossification 16 times. Of more abnormal significance was fusion of two carpal bones. In six cases the triquetrum and lunatum were fused in one hand only, and in eight cases in both hands. In two cases the capitatum and hamatum were fused in both hands, and in one case lunatum and naviculare were fused. In many cases, particularly in children whose skeletal development was below the average for their age group, transverse striae were observed running across the distal end of the radius parallel to the growing epiphyseal margin. Traces of these can be Seen in the plates shown in Figs. 5, 7, 8, 10, 11, 22 and 37. It is tempting to speculate as to whether these striae correspond to past periods of undernutrition or disease when normal bone formation was retarded, so that past medical history is revealed in the growing radius in the same way that the annual rings of trees record the past seasons. SELECTING THE AGE STANDARDS. It has previously been described how each X-ray film was inspected, and characteristics of bones and epiphyses recorded on punch cards, which on sorting allowed the frequency of these characteristics to be entered on charts similar to that shown in Table II. Once these charts had been completed for each age sex group it was a simple matter to determine those characteristics which were present in 50 per cent. or more subjects in each age group. For a film to qualify as being representative of the mean development of its age group it was essential in the first place that it should only possess those characteristics which were present in 50 per cent. or more subjects in the whole group. In practice it was fairly simple, after inspecting the charts, to get a rough mental picture of the characteristics such a film should possess. A likely looking film was then chosen from the group to be determined, and every other film in the group compared with it. Those that showed less development were put in a pile on one side, and those that showed more in a pile on the other. If after all films had been inspected the two piles were not equal in size, which rarely occurred, further search for a film either ascending or descending in degree of development, as the case might be, was then made, until a film was finally chosen which fell into the middle range of skeletal development in the whole group. This process of selection was carried out for each age group in both sexes, and Figs. 3 to 38 which follow are the final selections, and thus constitute an atlas of skeletal development in the hand of the children studied.
D. H. MACKAY
149
DISCUSSION.
Order of Appearance of the Carpal Centres. The study has revealed that there is no difference in the order of appearance of the ossification centres of the carpus from that recorded by FLORY (1936), and other authorities such as GRAY (1950). The order of appearance was found to be the same in both sexes.
Sex Difference. The more rapid appearance of ossification centres and progress to maturity in females than in males, first noted by PRYOR(1925), has been confirmed. Colnparison of the age standards for the two sexes makes it readily apparent that, although at 6 months the difference between the two sexes is not appreciable on inspection of the radiographs, yet thereafter, as age increases year by year, the females progress to maturity with an ever increasing lead over the males.
Rate of Progress of Maturation. When rate of progress of maturation is studied great differences are noted in comparing the African children with groups of American children in whom similar investigations have been made. The age standards produced by WINGATE TODD (1937) are on the whole rather more mature than those of FLORY (1936), SOthat comparisons which have already been made in the text between the Wadigo children and the Chicago children studied by FLORYdo not err in over emphasizing the speedier maturation rate of healthy American children. It will be seen from Tables III to VII that in the case of African children a greater time elapses from the first appearance of a carpal bone or epiphysis to the time when it is 100 per cent. present in all children examined, than in the American children ; and that on the whole the time of first appearance of carpal centres is later in the Africans than in the Americans. These two factors combine to produce a greater disparity as age progresses. If comparisons are made between the age standards for the Wadigo children and those of American children produced by FLORY(1936) and WINGATE TODD (1937) it will be seenthat the African children begin to lag behind from the 1st year, and that after the 5th year the difference becomes more and more marked, until by the age of 10, the Africans are 1½ to 2 years behind, and that by the age of 17½ this difference has still not been made up. The radiographs for the age standards of the Wadigo children were compared with the series of carpal X-rays contained in the study of 18 normal Michigan children by MACY (1946), and in no case did any of the American children equal or fall behind the African standards at appropriate ages. One other child in M~c¥'s study, (R.B.), suffering from hepatomegaly, lipaemia and rickets was X-rayed at 101 months. Comparison of his carpal radiograph with the male African standard
150
SKELETAL MATURATION IN THE HAND IN AFRICAN CHILDREN
for 102 months (8 years and 6 months) showed the African standard to be possibly 6 months more mature than the grossly abnormal American child. Work, so far unpublished, by PLATT on the body heights and weights for age of children in Nyasaland and the Gambia has shown that after the 1st year of life the growth curves tend to fall away from the values obtained with American or English children, and that from about 5 years and onwards the levels attained by the African children only continue to increase year by year at values attained by British and American children 2 years earlier. When nitrogen metabolism was investigated, the Gambian children, although they were eating enough to satisfy appetites, showed nitrogen retention levels normally attained 2 to 4 years earlier by the children in the United States investigated by MACY. The delay in skeletal maturation revealed by this investigation appears to fall into line with these findings of PLaTT, and provides one more link in the chain of reasoning leading to the assertion that the African children so far studied mature later than their Caucasian brethren. SUMMARY.
A radiological investigation of the ossification and maturation of the carpal bones in 1,350 East African children of known ages has been described. The work has revealed that there is no difference in the order of appearance of the carpal ossification centres from that commonly accepted for other races. The fact that skeletal maturation is more rapid in girls than in boys has been confirmed. The rate of skeletal maturation has been compared with findings of other writers on American children, and the African children investigated have been found to be from l½ to 2 years behind present American standards.
REFERENCES.
CARTER,THOMASM. (1926). J. educ. Psychol., 17, 237. FLORY, CHARLESD. (1936). Monographs of the Society for Research in Child Development, 1, 3. National Research Council, Washington. GRAY, H. (1950). Anatomy Descriptive and Applied, 30th Ed. by T. B. Johnston and J. Whillis, London : Longmans Green. MACY, ICIE G. (1946). Nutrition and Chemical Growth in Childhood, 2. Springfield, Ill. ; Charles C. Thomas. PLATT,~]3. S. (1951). Personal Communication. PRYOR,J.W. (1925). Amer. J. phys. Anthrop., 8, 401. TODD, THOMASWINGATE. (1937). Atlas of Skeletal Maturation ; with the collaboration of colleagues and assistants. 1926-36, London ; Kimptom.
ii ili~
FIo~ 3. Males. Age standard at 6 months. T h e capitatum and hamatum have appeared, but there is no trace of any epiphyseal centre. T h e r e are wide cartilaginous spaces between the several bones of the hand.
2:
FIG. 4. Males. Age standard at 1 year 6 months. T h e capitatum and h a m a t u m are larger, but no other carpal bone has yet appeared. A small wedge-shaped centre for the radial epiphysis is present. Metacarpals I I to V all have epiphyseal centres, as have the proximal phalanges, I n the distal row phalanges I to 1V have centres.
FIO 5. Males. Age standard at 2 years 6 months. l'here is no increase in the number of carpal bones. There is an in:tease in the size of bones and epiphyseal centres present at age 1 year 6 months.
FIo. 6. Males. Age standard at 3 years 6 months. The centre for the t r i q u e t r u m has appeared. All epiphyses except that for the ulna are present. T h e radial epiphysis is still small and wedge shaped.
FIG. 7. Males. Age standard at 4 years 6 months. F o u r carpal bones are present ; the capitatum, hamatum, t r i q u e t r u m and lunatum. T h e radial epiphysis has begun to extend towards the ulnar side, but does not yet equal the width of the shaft.
FIG. 8. Males. Age standard at 5 years 6 months. T h e capitatum and h a m a t u m have increased in size. T h e epiphyses at the heads of the metacarpals I I to I V are beginning to lose their cannon-ball appearance. T h e r e is an indication of the beginning of a saddle shape formation on the base of metacarpal l I .
>
FIG. 9. Males. Age standard at 6 years 6 months. T h e naviculare, m u l t a n g u l u m majus and m u l t a n g u l u m minus have all appeared. There is usually some variation in the order of their appearance. Metacarpal epiphyses I I to V are beginning to show a D-shaped outline. T h e radial epiphysis is still wedge shaped and does not equal the width of the shaft.
FIG. 10. Males. Age standard at 7 years 6 months. T h e carpal bones have increased i n size. I n this example m u l t a n g u l u m minus is absent. T h e epiphysis at the base of metacarpal I is beginning to enlarge, and the other metacarpal epiphyses are now definitely D-shaped. T h e radial epiphysis is approaching the ulnar margin of the radial head.
X
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FIG. 11. ZVIales. Age standard at 8 years 6 months. All carpal bones except the pisiforme are present, and the cartilaginous spaces between them are beginning to narrow. T h e saddle shaped outline at the base of metacarpal I I is now very distinct. T h e radial epiphysis has increased in size, but the ulnar epiphysis has not yet appeared.
FIG. 12. Males. Age-standard at 9 years 6 months. T h e ulnar epiphysis has appeared. T h e shadows of the capitatum and hamatum, and of m u l t a n g u l u m majus and minus are beginning to overlap. T h e epiphysis at the base of metacarpal I is equal'in breadth to the shaft.
FIG. 13. Males. Age standard at 10 years 6 months. All bones have increased in size. T h e radial epiphysis has thickened on the outer side, and the gap between the shaft has been reduced. T h e ulnar epiphysis is still small.
FIG. 14. Males. Age standard at 11 years 6 months. Gaps between the carpal bones have decreased, T h e shadows of t r i q u e t r u m l u n a t u m and naviculare are of approximateIy equal size. M u l t a n g u l u m majus has lost its roundness and shows a definite projection towards the base of metacarpal II. T h e ulnar epiphysis has increased in size.
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FIG. 55. Males. Age standard at 12 years 6 months. Fhere is m u c h more overlapping of carpal shadows. T h e metacarpal epiphyses are squaring off n preparation for union. T h e ulnar epiphysis is nearly equal in breadth to the shaft, and the ulnar styloid has appeared.
FIG. 16. Males. A g e standard at 13 years 6 months. T h e shadows of m u l t a n g u l u m majus and h a m a t u m overlap the ends of metacarpals I I and V respectively. T h e r e is a well-marked beak on the ulnar side of the radial epiphysis, T h e gaps between epiphyses and metacarpals I I to V have almost closed.
FIG. 17. Males. Age standard at 14 years 6 months. T h e centre for the pisiforme has appeared. T h e gap between the epiphysis and metacarpal I has narrowed. T h e saddle shape at the base of metacarpaI I I fits more closely over multang u l u m minus. T h e ulnar epiphysis is equal in breadth to the shaft.
FIG. 18. Males. Age standard at 15 years 6 months. T h e outer side of the radial epiphysis is beginning to lose its roundness and square off. All epiphyseal gaps are being reduced. T h e shadow of the pisiforme is larger. A sesamo[d has appeared at the distal end of metacarpal I.
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FIG. 19. Males. Age standard at 16 years 6 months. T h e squared outer end of the radial epiphysis is beginning to turn down towards the shaft. T h e metacarpal epiphyses appear to have begun to unite. T h e carpal space appears to be filled with bone, and few gaps are apparent.
FIG. 20. Males. Age standard at 17 years 6 months. U n i o n of the metacarpal epiphyses is nearing completion. T h e turned-down beaks of the radial epiphysis on the ulnar and radial sides are more pronounced, and the gap between epiphysis and shaft is very narrow. T h e hand is not yet fully mature.
FIG, 2 i . Females. Age standard at 6 months. T h e eapitatum and h a m a t u m are present but there is no trace of any epiphyseal centre,
F ~ . 22. Females. Age standard at 1 year 6 months, T h e capitatum and h a m a t u m are larger, but no other carpal bone has yet appeared. A wedge-shaped radial epiphysis is present. Epiphyseal centres for metacarpals I I to V and proximal phalanges I I to V are present,
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FIG. 23. Females. Age standard at 2 years 6 months. T h e centre for the triquetrum has appeared, and all metacarpal and pha]angeal epiphyses are present.
FIG. 24. Females. Age standard at 3 years 6 months. Five carpal centres are now present, the h m a t u m and naviculare having made their appearance. T h e epiphyses of metacarpals I I to V still present a cannon-ball appearance.
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FIG. 25. Females. Age standard at 4 years 6 months. T h e h a m a t u m is losing its rounded appearance and is b e c o m i n g wedge shaped. F i v e carpal bones are still present, but in this example multangu l u m majus replaces naviculare. T h e epiphyses for metacarpals H, I I I and I V are b e c o m i n g D-shaped.
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FIG. 26. Females. Age standard at 5 years 6 months. t h e radial epiphysis is still wedge shaped but is extending towards the ulnar ~ide. T h e r e is a faint indication of a saddle shape at the base of metacarpal II,
FIG. 27. Females. Age standard at 6 years 6 months. All carpai bones except pisiforme are present, and are more m a t u r e than in boys of the same age. T h e radial epiphysis has extended still f u r t h e r towards the u l n a r side.
FIG. 28.
Females.
Age standard at 7 years 6 months, F h e r e is an increase in bone raze, and the shadows of the capitatum and h a m a t u m and of m u l t a n g u l u m majns and minus are beginning to overlap. T h e r e is still much open space in the carpus. T h e D - s h a p e d appearance of the metacarpal epiphyses is now more marked.
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FIG, 3I. Females. Age standard at 10 years 6 months. T h e r e is a further increase in the size of the carpal bones. T h e radial epiphysis is equal in breadth to the shaft.
FIO. 32. Females. ~_ge standard at 11 years 6 months. T h e pisiforme has appeared, but is somewhat obscured by the overlying triquetrum, Shadows of m u l t a n g u l u m majus and h a m a t u m overlap the bases of metacarpals I I and V respectively. T h e r e is a well m a r k e d ulnar beak on the radial epiphysis, and the ulnar epiphysis is equal in breadth to the shaft.
]rio. 33. Females. Age standard at 12 years 6 months. T h e metacarpal epiphyses are getting ready for fusion. T h e radial epiphysis has squared off on its outer aspect, and is coming more into relation with l u n a t u m and naviculare. T h e phalangeal epiphyses are equal in breadth to their respective shafts.
FIG. 34. Females. Age standard at 13 years 6 months. T h e metacarpal epiphyses have started to fuse. T h e ulnar beak on the radial epiphysis is t u r n i n g down towards the shaft, and the epiphyseaI gap has narrowed. A sesamoid has appeared at the distal end of metacarpal I. T h e ulnar epiphysis is equal in breadth to the shaft.
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FIG. 35. Females. Age standard at 14 years 6 months. U n i o n is progressing in the metacarpal epiphyses. The radial epiphysis has developed a beak on the outerside t u r n i n g down towai'ds the shaft. T h e ulnar epiphysis is uniting. M u l t a n g u l u m minus is in close relationship with the saddle shaped end of metacarpal II.
SKELETAL MATURATION IN THE HAND IN AFRICAN CHILDREN
41
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FIG. 36. Females. Age standard at 15 years 6 months. U n i o n of all epiphyses is still progressing. T h e epiphyseal gap between the radial epiphysis and shaft has narrowed still further.
9.
3
SKELETAL M A T U R A T I O N I N THE HAND I N AFRICAN C H I L D R E N
FIG. 38. Females. Age standard at 17 years 6 months. Fusion of metacarpal and phalangeal epiphyses is complete. T h e radial and ulnar epiphyses have not quite united with their shafts at their outer edges, otherwise the hand appears to be fully mature.
COMMUNICATIONS S K E L E T A L M A T U R A T I O N IN T H E H A N D : A STUDY OF D E V E L O P M E N T IN EAST AFRICAN CHILDREN. BY
D. H. MACKAY, M.R.C.S., L.R.C.P., D.P.H., D.T.M. & H.* Colonial Medical Service, Kenya.
In the progress of a child from birth to maturity chronological age affords an insufficient measure of assessing development, as children of equal age differ widely in their degree of physical development. Many methods have been devised of more accurately measuring progress. Among these, studies of heights and weights in relation to age, and the determination of intellectual attainment by intelligence tests have contributed knowledge on physical and mental development. As a further index of physical development the growth pattern of the skeletal framework of the body has been studied, and techniques have been devised, notably in America, of estimating skeletal maturation by radiography. These techniques have resulted in standards for the skeletal development of Caucasian children being laid down. No similar standards exist for any of the African peoples. In East Africa any attempt to relate physical development to age has been difficult or impossible owing to the absence generally of reliable statistics based on birth registration. Before making comparisons between the physical development of AfriCan and Caucasian children it seems essential that not only the rate, but the pattern, of their progress to maturity should be studied. I t was therefore considered that an investigation of skeletal maturation in African children, by contributing basic information as to the bodily framework on which their physical development was founded, would form a useful basis for making comparisons with children of other races. The account of the work that follows is of an attempt to study the pattern *My thanks are due to the Hon. Director of Medical Services, Kenya, for permission to submit this paper, to Professor G. MACDONALDfor considerable help and encouragement throughout the work, and to my wife for clerical assistance and practical help in gaining the confidence of the children during their examination. My thanks are also due to the Secretary of State for the Colonies, who, on the recommendation of the Colonial Medical Research Committee, contributed generously from research funds, provided under the Colonial Development and Welfare Acts, to the publication of the Figures that illustrate this paper.
1__36
SKELETAL MATURATION IN THE HAND IN AFRICAN CHILDREN
and rate of skeletal growth in the hand of children of one particular East African tribe, carried out with the object of formulating skeletal age standards for them. THE
POPULATION
STUDIED.
The Wadigo, a tribe of Bantu origin, occupy a strip of the East African coast extending from Mombasa in the north to Tanga in the south.. Halfway between Mombasa and the Tanganyika border is a thickly populated area called Msambweni which consists of a series of contiguous villages. i
l'q°'h;
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I
Roughly indicates area inhabited by the Wadlgo.
The climate is tropical with an annual rainfall of over 45 inches, and ancylostomiasis and subtertian malaria are hyperendemic. Anaemia associated with ancylostomiasis is universal. The Wadigo of Msambweni cultivate some rice, but their staple diet is cassava. S o m e cattle are kept, but little milk is consumed, at any rate by children. Fishing forms one of the major occupations of the community, and seafish provide the most frequent source of animal protein. In 1927 the area received its first organized medical attention when a mass treatment and sanitation campaign against hookworm was carried out by MACLENNAN and PHILIP. Subsequently Msambweni was chosen as a site for a govern-
D. H . MACKAY
FIG. 1.
FIo. 2.
Chief Salim Mohamed, with the aid of the Birth Register, checking the children before examination.
Illustrating the position of the subject when radiographs were taken,
137
D. H. MACKAY
139
ment hospital and the centre of future medical activities. PHILIP remained as the first medical officer of health. One of his first acts was to persuade the people to accept a voluntary scheme for the registration of births and deaths. African Sanitary Assistants were trained, as part of their duties, to collect information as to births and deaths, and to enter it in a central register kept at the hospital. As the years went by, and the work of the hospital increased subsequent medical officers were unable to devote much attention to the scheme especially as it was felt that in the absence of any statutory compulsion many births and deaths were being unrecorded, and that statistics derived from those that were registered were therefore unreliable. Partial notification of births however has continued until the present day, the greater number of notifications being received from those villages nearest to the hospital. At the time this study started there thus existed an appreciable child population near to the hospital of ascertainable age. METHOD.
From the central register of births names of children born in the area in various years, together with the names of their parents, were abstracted. Lists were then given to the Sanitary Assistants who went out and endeavoured to trace the children on their lists. In many cases the children had died, or had moved away to another place, or for some other reason could not be traced, but there remained a substantial number appearing to answer to the particulars in the register. Careful checking was necessary, particularly as the name by which the child was registered was not always the name by which he was known in later years. Considerable help was given by the village elders, and by the Chief, who had previously been one of the original Sanitary Assistants engaged in the work of registration. Consent was then obtained from the parents for the child to attend the hospital on special mornings set aside for examinations. On arrival at the hospital further checking with the aid of the Chief and elders was necessary, as it was not uncommon for the parents to get muddled and bring the wrong children, or for a boy to send along a brother in his place. When a batch of children had been verified beyond reasonable doubt they were given tickets bearing their names and dates of birth, and kept under observation until they were examined in order to prevent exchange of tickets. Before being submitted to radiography measurements of height, sitting height, pelvic diameter and weight were made, and dental state recorded in detail. It is hoped that analysis of the data thus obtained will form the subject of a subsequent paper. Both hands were X-rayed, using a portable Victor X-Ray unit powered by a petrol electric generator. A standard tube length of 30 inches was maintained for all exposures. The film holder was placed on a table with the X-ray tube vertically above. Care was taken to place the subject so that the forearm was laid
140
SKELETAL M A T U R A T I O N I N THE HAND I N AFRICAN C H I L D R E N
flat on the table, the body of the child being caused to lean to one side in order to ensure that the lower end of the radius did not rotate about the ulna. Each. film was n u m b e r e d at the time of exposure by means of a metal device, the n u m b e r of the film corresponding with the serial n u m b e r on the card used for recording l~irth dates and body measurements. NUMBER OF CtIILDREN EXAMINED. T h e total n u m b e r of children examined was 1,360, m a d e up of 602 girls and 758 boys. T h e i r distribution by age and sex is given in T a b l e I below. TABLE 1. Number Of children examined by age and sex. Age.
Girls.
Boys,
Total.
0--
1234567891011121314151617-18
51 39 45 23 28 26 35 31 36 33 39 41 26 42 25 32 38 12
49 69 41 25 30 48 37 44 43 44 50 51 41 30 40 32 74 10
100 108 86 48 58 74 72 75 79 77 89 92 67 72 65 64 112 22
Total
602
,
I
758
1,360
METHOD OF ANALYSING THE DATA. I n an endeavour to record objectively the sum total of the variables relating to carpal bones and epiphyses in each X - r a y the following technique was evolved. Each pair of X - r a y films was inspected and the chronological age, and sex of the child, the presence of ossification centres of bones and epiphyses, and also certain readily recognisable features of some bones and epiphyses were then marked off on n u m b e r s allotted to t h e m on Findex ptmch cards. W h e r e development in one hand was greater than iaa the other, which occurred not infrequently in the younger age groups when new centres were appearing, the hand showing the greater degree of development was recorded. No attempt was m a d e to assess development b y measuring with a planimeter the areas of the shadows Of the carpal bones as was done by CARTER (1926) and FLORY (1936), as it was thought that such a
D. H. MACKAY
141
method, involving a time consuming and difficult technique, does not give results superior to that of a careful inspectional analysis. W h e n every film had been inspected and recorded the cards were sorted first into sexes, and then into age groups. As the children in each age group varied in chronological age throughout the whole range of 12 months the average age of each age group fell at 6 m o n t h s over the last birthday. For example, a child who had attained his 10th birthday but had not yet reached his l l t h would be placed in the group I0-11, and the average age of his group would be 10 years and 6 months. It will be important to bear this point in mind when comparisons are made later with FLORY'S studies (1936), as his subjects were all radiographed within a fortnight of their birthday, and thus a 10-year old by his standards is 6 months younger than a child in the 10-year group in this study. T h e cards for each age sex group w e r e then sorted for the frequency of occurrence of each characteristic recorded, and tabulated under headings as shown in T a b l e II. F r o m the data thus tabulated it was then possible to prepare charts showing the appearance of the carpal bones and epiphyses in each age sex group expressed as percentage present, and to estimate probable times of appearances. , TABLE II.
Chart showing characteristics recorded.
Sex : M . orF. Age : Number in Group : Capitatum : Hamatum : Triquetrum : Lunatum : Naviculare :
R a d i a l Epiphysis.
Ulnar Epiphysis.
Present : ,, and equal : ,, 5 ulnar beak : ,, ~ radial beak : Fusion started : Fusion complete :
Present : ,, and equal : ,, "d styloid : Fusion started : Fusion complete :
Metacarpals
I
II
III
IV
-V
I
II
III
IV
V
Muh. majus : Present : with horn : Fusion started : overlaps Met II : Fusion complete : Mult. minus : overlaps M. maius Hamatum overlaps Met. V :
Prox. Phalanges
Present : Fusion started :
Sesamoids : Fusion complet e : Development
Right greater than Left : Left greater than Right : Right and Left equal : Abnormalities :
142
SKELETAL MATURATION IN THE HAND IN AFRICAN CHILDREN ANALYSIS OF RESULTS.
The Appearance of the Carpal Bones. The capitatum and hamatum were invariably the first bones to appear, usually together. The radial epiphysis followed, and then successively triquetrum, lunatum and naviculare. Multangulum majus and minus next appeared, but the order in which naviculare and the multangulars appeared was subject to much variation. The ulnar epiphysis followed the multangular bones, and was in turn followed by the pisiforme. The sesamoid bones at the distal end of metacarpal I were the last to make their appearance.
Sex Differences in the Ossification of the Hand. There are sex differences in the times of appearance of centres of ossification. These are slight at first, but in each succeeding year girls become more advanced than boys, so that by the age of 9½ years the average girl is 1½ to 2 years skeletally more mature than the average boy. This sex difference is demonstrated in the tables and age standards which follow.
The Times of Appearance of the Carpal Bones. Table III which follows shows the appearance of the carpal bones, including the radial and ulnar epiphyses, of the boys and girls examined expressed as percentage present, while Table IV shows the results obtained by FLORY (1936), working with Chicago school children.
Comparison between Tables I H and IV. Inspection of Tables III and IV reveals that while the order of appearance of the carpal ossification centres is similar, the African children take longer from the time of first appearance of an ossification centre to reach a point where that centre is present in all hands. This increased variability becomes more marked as age progresses. It is also apparent from comparison of the two tables that the African children take longer to reach skeletal maturity in the hand than the Chicago children. The shift to the right of the figures in the table for African children becomes even more marked when it is remembered that in Table III figures refer to mean age at the ½ year over each birthday, while in Table IV they refer to percentages of centres present 6 months earlier on the birthday.
....
....
8esarnoids
epiphysis
Pisiforme
Ulnar
..
F M
0t
F M
I
0 0
0
0 0
0 0
0 0
0 0
18 12
51 41
85 52
i °
0 0
0 0
F M
F M
0 0
F M
..
0 0
F M
....
Navieulare
Mult. minus
2 3
F M
....
Lunatum
..
2O 14
F M
Triquetrum
Mult. majus
20 8
F M
Radial epiphysis
00 00
86 84
F M
••
Hamatum
00 00
88 92
F
....
.-
O-L
Sex.
0 0
0 0
0 0
ol
0
0 0
2 0~
24 12
69 46
96 76
2-
0 0
0 0
0 0
32 0
3~ 7
32 13
68 50
75 83
93 97
4-
0 0
0 0
12 0
46 17
50 25
46 23
69 62
O0 O0
96 O0
5-
23 16
74 54
60 59
0 0
0 0
45 16
94 52
97 52
0 0
8 0
72 44
94 84
97 84
94 86
00 98
Age
3 0
27 2
88 80
100 95
100 95
5 0
31 2
95 76
95 100
98
37 8
61 18
100 98
100 98
96
98
98
11-
46 5
73 17
100 93
100
100
100
100
12-
90 17
90 27
98 100
13-
92 30
96 55
100
14-
97 66
O0 81
15-
T h e a p p e a r a n c e of t h e carpal b o n e s of boys a n d girls e x p r e s s e d i n p e r c e n t a g e p r e s e n t .
Capitatum
Bone.
TABLE I I I .
90
90
17-18
t~
F.
..
Triquetrum
..
• °
Mult. minus
Ulnar epiphysis
..
..
M u l t . majus
Pisiforme
..
Naviculare
. . . .
..
Radial epiphysis
Lunatum
..
. . . .
I
M
F
M
F
F
F M
h
Sex.
0
o
°o
o
o o
0 0
0 0 0 0
0 0
0 0
0 0
0 8
20 22
0 0
0 0
78 34
96 98
0 0
8 2
o
0 0
0 0
4 0
0 0
32 18
52 50
O0 98
100
loo
100
/
0 0
0 0
15 4
18 4
12 4
50 36
79 57
100
3
0 0
0 0
40 22
53 14
30 17
80 64
100 92
4
0 0
6 7
;5 9
'4 ~3
;1 14
~1 ;4
',4
5
0 0
60 27
95 48
94 51
95 51
99 87
93
90 59
100 81
99 72
99 75
100 98
100
7
19 2
100 82
95
100 88
100 92
99
Age 8
50 6
98
100
96
99
100
9
79 22
100
99
97
99
10
96 28
100
100
100
11
100 66
12
95
13
99
14
99
15
T h e a p p e a r a n c e o f carpal bones for boys a n d girls e x p r e s s e d in p e r c e n t a g e p r e s e n t according to FLORY o n U n i v e r s i t y of Chicago L a b o r a t o r y school children.
Hamatum
Capitatum
Bone.
TABLE IV.
100
16
ra
w
z
2
t~
D.
H,
MACKAY
145
Probable Age of Appearance of Carpal Bones in Months. T h e probable age of appearance is considered to be the age at which 50 per cent. of the subjects showed a centre present. This point can be estimated by inspection of Table III. FLORY (1936) followed the same practice in estimating age of appearance in the Chicago school children. In Table V are set out the probable ages of appearance in months of the carpal centres in the Wadigo children, and FLORY'S estimates for the Chicago children. TABLE V. Probable age of appearance of carpal bones in months.
Bone. Capitatum . . . . Hamatum Radial epiphysis Triquetrum Lunatum . . . . Naviculare Mult. majus Mult. minus Ulnar epiphysis Pisiforme . . . .
.. .. ..
• .
.. .. .. .. • .
Wadigo Children
Chicago Children
Males.
Females.
Males
Females.
6 6 18 34 54 72 78 78 98 166
6 6 13 18 42 63 66 68 93 132
6 6 15 24 42 72 72 73 80 140
6 6 9 23 36 56 50 53 68 108
The Metacarpal and Phalangeal Epiphyses. Metacarpal epiphyses II to V start to appear in that order by about the 1st birthday in girls, and 9 months to a year later in boys. T h e epiphyseal centre for metacarpal I appears around the 2nd birthday in girls, and at about 3 years and 6 months in boys. T h e epiphyseal centres for the proximal phalanges, with the exception of the centre for phalanx I, appear in girls by the 1st birthday, and in boys by about the 2nd. Centres for the distal phalanges appear a little later. In Table VI are shown the percentage of these centres present at successive ages in the Wadigo children studied, and in Table VII are the results obtained by FLORY (1936) in the Chicago school children. It will be seen from these tables that in the case of the African children studied progress towards attaining 100 per cent. representation of metacarpal and phalangeal epiphyses is spread out over a much longer period of time, and evenually is reached at a much later age than in the American children•
146
SKELETAL
TABLE VI.
MATURATION
IN
THE
HAND
IN
AFRICAN
CHILDREN
T h e percentage of metacarpal and proximal phalangeal epiphyses present in Wadigo children at successive ages.
Age.
~piphyses.
Sex
o- ¸ 1-I~:13-
~
~- 6- 7- 8-~9-, 10-111-~12-J13-rl~-,,,,
r
Metacarpals
m__
__
' I
F M
0 0
1849 78 82 88 97100 0 0 60~ 63 77 89 98!9395
II
F M
12 0
III
F M
12 92 93i100 0 35 76 96 100
IV
F M
8 79 91 100 96 100 0 29 71 96 97 98 100
V
F M
6 69 91 100 96 100 0 1761 96 93 98 100
I
F M
100 0 21 73 91 93 , 0 0 5 56 70 94 100
II
F M
10 95 98 100 6 33 93 96 100
III
F M
16 100 8 44 93
IV
F M
14 97 98 100 6 32 85 96 100
V
F M
92 96 100 33 78 96 100
Proximal phalanges
96 100
6 6291 100 0 12 50 96
96i100 93 98 100
98 100
93
87100
D. H. MACKAY
TABLE V I I .
147
T h e p e r c e n t a g e of m e t a c a r p a l a n d p r o x i m a l p h a l a n g e a l e p i p h y s e s p r e s e n t in Chicago c h i l d r e n according to FLORY. Age. Epiphyses.
Sex. 2
3
4
I
Metacarpals F
18 0
80 25
100 93
! [
.
M
II
. . . . . .
F M
42 12
92 90
100 100
,
III
. . . . . .
F M
38 10
92 78
100 100
IV
. . . . . .
F M
28 6
92 78
100 100
V
. . . . . .
F M
24 0
92 65
100 100
I
.
.
.
.
.
! l
5
i
-
97
100
100 97
100
;
Proximal phalanges F
8
.
M
0
72 18
97 100
II
. . . . . .
F M
58 20
92 98
100 100
III
. . . . . .
F M
58 22
92 98
100 100
IV
. . . . . .
F M
58 20
92 95
100 100
V
. . . . . .
F M
36 2
92 88
100 100
I
.
.
.
.
.
148
SKELETAL M A T U R A T I O N I N THE HAND I N AFRICAN C H I L D R E N
Abnormalities. Various developmental anomalies were noted in the series. Pseudoepiphyses at the proximal end of metacarpal II occurred 25 times, and at the distal end of metacarpal I 16 times. The ulnar epiphysis presented a double centre of ossification 16 times. Of more abnormal significance was fusion of two carpal bones. In six cases the triquetrum and lunatum were fused in one hand only, and in eight cases in both hands. In two cases the capitatum and hamatum were fused in both hands, and in one case lunatum and naviculare were fused. In many cases, particularly in children whose skeletal development was below the average for their age group, transverse striae were observed running across the distal end of the radius parallel to the growing epiphyseal margin. Traces of these can be Seen in the plates shown in Figs. 5, 7, 8, 10, 11, 22 and 37. It is tempting to speculate as to whether these striae correspond to past periods of undernutrition or disease when normal bone formation was retarded, so that past medical history is revealed in the growing radius in the same way that the annual rings of trees record the past seasons. SELECTING THE AGE STANDARDS. It has previously been described how each X-ray film was inspected, and characteristics of bones and epiphyses recorded on punch cards, which on sorting allowed the frequency of these characteristics to be entered on charts similar to that shown in Table II. Once these charts had been completed for each age sex group it was a simple matter to determine those characteristics which were present in 50 per cent. or more subjects in each age group. For a film to qualify as being representative of the mean development of its age group it was essential in the first place that it should only possess those characteristics which were present in 50 per cent. or more subjects in the whole group. In practice it was fairly simple, after inspecting the charts, to get a rough mental picture of the characteristics such a film should possess. A likely looking film was then chosen from the group to be determined, and every other film in the group compared with it. Those that showed less development were put in a pile on one side, and those that showed more in a pile on the other. If after all films had been inspected the two piles were not equal in size, which rarely occurred, further search for a film either ascending or descending in degree of development, as the case might be, was then made, until a film was finally chosen which fell into the middle range of skeletal development in the whole group. This process of selection was carried out for each age group in both sexes, and Figs. 3 to 38 which follow are the final selections, and thus constitute an atlas of skeletal development in the hand of the children studied.
D. H. MACKAY
149
DISCUSSION.
Order of Appearance of the Carpal Centres. The study has revealed that there is no difference in the order of appearance of the ossification centres of the carpus from that recorded by FLORY (1936), and other authorities such as GRAY (1950). The order of appearance was found to be the same in both sexes.
Sex Difference. The more rapid appearance of ossification centres and progress to maturity in females than in males, first noted by PRYOR(1925), has been confirmed. Colnparison of the age standards for the two sexes makes it readily apparent that, although at 6 months the difference between the two sexes is not appreciable on inspection of the radiographs, yet thereafter, as age increases year by year, the females progress to maturity with an ever increasing lead over the males.
Rate of Progress of Maturation. When rate of progress of maturation is studied great differences are noted in comparing the African children with groups of American children in whom similar investigations have been made. The age standards produced by WINGATE TODD (1937) are on the whole rather more mature than those of FLORY (1936), SOthat comparisons which have already been made in the text between the Wadigo children and the Chicago children studied by FLORYdo not err in over emphasizing the speedier maturation rate of healthy American children. It will be seen from Tables III to VII that in the case of African children a greater time elapses from the first appearance of a carpal bone or epiphysis to the time when it is 100 per cent. present in all children examined, than in the American children ; and that on the whole the time of first appearance of carpal centres is later in the Africans than in the Americans. These two factors combine to produce a greater disparity as age progresses. If comparisons are made between the age standards for the Wadigo children and those of American children produced by FLORY(1936) and WINGATE TODD (1937) it will be seenthat the African children begin to lag behind from the 1st year, and that after the 5th year the difference becomes more and more marked, until by the age of 10, the Africans are 1½ to 2 years behind, and that by the age of 17½ this difference has still not been made up. The radiographs for the age standards of the Wadigo children were compared with the series of carpal X-rays contained in the study of 18 normal Michigan children by MACY (1946), and in no case did any of the American children equal or fall behind the African standards at appropriate ages. One other child in M~c¥'s study, (R.B.), suffering from hepatomegaly, lipaemia and rickets was X-rayed at 101 months. Comparison of his carpal radiograph with the male African standard
150
SKELETAL MATURATION IN THE HAND IN AFRICAN CHILDREN
for 102 months (8 years and 6 months) showed the African standard to be possibly 6 months more mature than the grossly abnormal American child. Work, so far unpublished, by PLATT on the body heights and weights for age of children in Nyasaland and the Gambia has shown that after the 1st year of life the growth curves tend to fall away from the values obtained with American or English children, and that from about 5 years and onwards the levels attained by the African children only continue to increase year by year at values attained by British and American children 2 years earlier. When nitrogen metabolism was investigated, the Gambian children, although they were eating enough to satisfy appetites, showed nitrogen retention levels normally attained 2 to 4 years earlier by the children in the United States investigated by MACY. The delay in skeletal maturation revealed by this investigation appears to fall into line with these findings of PLaTT, and provides one more link in the chain of reasoning leading to the assertion that the African children so far studied mature later than their Caucasian brethren. SUMMARY.
A radiological investigation of the ossification and maturation of the carpal bones in 1,350 East African children of known ages has been described. The work has revealed that there is no difference in the order of appearance of the carpal ossification centres from that commonly accepted for other races. The fact that skeletal maturation is more rapid in girls than in boys has been confirmed. The rate of skeletal maturation has been compared with findings of other writers on American children, and the African children investigated have been found to be from l½ to 2 years behind present American standards.
REFERENCES.
CARTER,THOMASM. (1926). J. educ. Psychol., 17, 237. FLORY, CHARLESD. (1936). Monographs of the Society for Research in Child Development, 1, 3. National Research Council, Washington. GRAY, H. (1950). Anatomy Descriptive and Applied, 30th Ed. by T. B. Johnston and J. Whillis, London : Longmans Green. MACY, ICIE G. (1946). Nutrition and Chemical Growth in Childhood, 2. Springfield, Ill. ; Charles C. Thomas. PLATT,~]3. S. (1951). Personal Communication. PRYOR,J.W. (1925). Amer. J. phys. Anthrop., 8, 401. TODD, THOMASWINGATE. (1937). Atlas of Skeletal Maturation ; with the collaboration of colleagues and assistants. 1926-36, London ; Kimptom.
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FIo~ 3. Males. Age standard at 6 months. T h e capitatum and hamatum have appeared, but there is no trace of any epiphyseal centre. T h e r e are wide cartilaginous spaces between the several bones of the hand.
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FIG. 4. Males. Age standard at 1 year 6 months. T h e capitatum and h a m a t u m are larger, but no other carpal bone has yet appeared. A small wedge-shaped centre for the radial epiphysis is present. Metacarpals I I to V all have epiphyseal centres, as have the proximal phalanges, I n the distal row phalanges I to 1V have centres.
FIO 5. Males. Age standard at 2 years 6 months. l'here is no increase in the number of carpal bones. There is an in:tease in the size of bones and epiphyseal centres present at age 1 year 6 months.
FIo. 6. Males. Age standard at 3 years 6 months. The centre for the t r i q u e t r u m has appeared. All epiphyses except that for the ulna are present. T h e radial epiphysis is still small and wedge shaped.
FIG. 7. Males. Age standard at 4 years 6 months. F o u r carpal bones are present ; the capitatum, hamatum, t r i q u e t r u m and lunatum. T h e radial epiphysis has begun to extend towards the ulnar side, but does not yet equal the width of the shaft.
FIG. 8. Males. Age standard at 5 years 6 months. T h e capitatum and h a m a t u m have increased in size. T h e epiphyses at the heads of the metacarpals I I to I V are beginning to lose their cannon-ball appearance. T h e r e is an indication of the beginning of a saddle shape formation on the base of metacarpal l I .
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FIG. 9. Males. Age standard at 6 years 6 months. T h e naviculare, m u l t a n g u l u m majus and m u l t a n g u l u m minus have all appeared. There is usually some variation in the order of their appearance. Metacarpal epiphyses I I to V are beginning to show a D-shaped outline. T h e radial epiphysis is still wedge shaped and does not equal the width of the shaft.
FIG. 10. Males. Age standard at 7 years 6 months. T h e carpal bones have increased i n size. I n this example m u l t a n g u l u m minus is absent. T h e epiphysis at the base of metacarpal I is beginning to enlarge, and the other metacarpal epiphyses are now definitely D-shaped. T h e radial epiphysis is approaching the ulnar margin of the radial head.
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FIG. 11. ZVIales. Age standard at 8 years 6 months. All carpal bones except the pisiforme are present, and the cartilaginous spaces between them are beginning to narrow. T h e saddle shaped outline at the base of metacarpal I I is now very distinct. T h e radial epiphysis has increased in size, but the ulnar epiphysis has not yet appeared.
FIG. 12. Males. Age-standard at 9 years 6 months. T h e ulnar epiphysis has appeared. T h e shadows of the capitatum and hamatum, and of m u l t a n g u l u m majus and minus are beginning to overlap. T h e epiphysis at the base of metacarpal I is equal'in breadth to the shaft.
FIG. 13. Males. Age standard at 10 years 6 months. All bones have increased in size. T h e radial epiphysis has thickened on the outer side, and the gap between the shaft has been reduced. T h e ulnar epiphysis is still small.
FIG. 14. Males. Age standard at 11 years 6 months. Gaps between the carpal bones have decreased, T h e shadows of t r i q u e t r u m l u n a t u m and naviculare are of approximateIy equal size. M u l t a n g u l u m majus has lost its roundness and shows a definite projection towards the base of metacarpal II. T h e ulnar epiphysis has increased in size.
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FIG. 55. Males. Age standard at 12 years 6 months. Fhere is m u c h more overlapping of carpal shadows. T h e metacarpal epiphyses are squaring off n preparation for union. T h e ulnar epiphysis is nearly equal in breadth to the shaft, and the ulnar styloid has appeared.
FIG. 16. Males. A g e standard at 13 years 6 months. T h e shadows of m u l t a n g u l u m majus and h a m a t u m overlap the ends of metacarpals I I and V respectively. T h e r e is a well-marked beak on the ulnar side of the radial epiphysis, T h e gaps between epiphyses and metacarpals I I to V have almost closed.
FIG. 17. Males. Age standard at 14 years 6 months. T h e centre for the pisiforme has appeared. T h e gap between the epiphysis and metacarpal I has narrowed. T h e saddle shape at the base of metacarpaI I I fits more closely over multang u l u m minus. T h e ulnar epiphysis is equal in breadth to the shaft.
FIG. 18. Males. Age standard at 15 years 6 months. T h e outer side of the radial epiphysis is beginning to lose its roundness and square off. All epiphyseal gaps are being reduced. T h e shadow of the pisiforme is larger. A sesamo[d has appeared at the distal end of metacarpal I.
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FIG. 19. Males. Age standard at 16 years 6 months. T h e squared outer end of the radial epiphysis is beginning to turn down towards the shaft. T h e metacarpal epiphyses appear to have begun to unite. T h e carpal space appears to be filled with bone, and few gaps are apparent.
FIG. 20. Males. Age standard at 17 years 6 months. U n i o n of the metacarpal epiphyses is nearing completion. T h e turned-down beaks of the radial epiphysis on the ulnar and radial sides are more pronounced, and the gap between epiphysis and shaft is very narrow. T h e hand is not yet fully mature.
FIG, 2 i . Females. Age standard at 6 months. T h e eapitatum and h a m a t u m are present but there is no trace of any epiphyseal centre,
F ~ . 22. Females. Age standard at 1 year 6 months, T h e capitatum and h a m a t u m are larger, but no other carpal bone has yet appeared. A wedge-shaped radial epiphysis is present. Epiphyseal centres for metacarpals I I to V and proximal phalanges I I to V are present,
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FIG. 23. Females. Age standard at 2 years 6 months. T h e centre for the triquetrum has appeared, and all metacarpal and pha]angeal epiphyses are present.
FIG. 24. Females. Age standard at 3 years 6 months. Five carpal centres are now present, the h m a t u m and naviculare having made their appearance. T h e epiphyses of metacarpals I I to V still present a cannon-ball appearance.
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FIG. 25. Females. Age standard at 4 years 6 months. T h e h a m a t u m is losing its rounded appearance and is b e c o m i n g wedge shaped. F i v e carpal bones are still present, but in this example multangu l u m majus replaces naviculare. T h e epiphyses for metacarpals H, I I I and I V are b e c o m i n g D-shaped.
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FIG. 26. Females. Age standard at 5 years 6 months. t h e radial epiphysis is still wedge shaped but is extending towards the ulnar ~ide. T h e r e is a faint indication of a saddle shape at the base of metacarpal II,
FIG. 27. Females. Age standard at 6 years 6 months. All carpai bones except pisiforme are present, and are more m a t u r e than in boys of the same age. T h e radial epiphysis has extended still f u r t h e r towards the u l n a r side.
FIG. 28.
Females.
Age standard at 7 years 6 months, F h e r e is an increase in bone raze, and the shadows of the capitatum and h a m a t u m and of m u l t a n g u l u m majns and minus are beginning to overlap. T h e r e is still much open space in the carpus. T h e D - s h a p e d appearance of the metacarpal epiphyses is now more marked.
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FIG, 3I. Females. Age standard at 10 years 6 months. T h e r e is a further increase in the size of the carpal bones. T h e radial epiphysis is equal in breadth to the shaft.
FIO. 32. Females. ~_ge standard at 11 years 6 months. T h e pisiforme has appeared, but is somewhat obscured by the overlying triquetrum, Shadows of m u l t a n g u l u m majus and h a m a t u m overlap the bases of metacarpals I I and V respectively. T h e r e is a well m a r k e d ulnar beak on the radial epiphysis, and the ulnar epiphysis is equal in breadth to the shaft.
]rio. 33. Females. Age standard at 12 years 6 months. T h e metacarpal epiphyses are getting ready for fusion. T h e radial epiphysis has squared off on its outer aspect, and is coming more into relation with l u n a t u m and naviculare. T h e phalangeal epiphyses are equal in breadth to their respective shafts.
FIG. 34. Females. Age standard at 13 years 6 months. T h e metacarpal epiphyses have started to fuse. T h e ulnar beak on the radial epiphysis is t u r n i n g down towards the shaft, and the epiphyseaI gap has narrowed. A sesamoid has appeared at the distal end of metacarpal I. T h e ulnar epiphysis is equal in breadth to the shaft.
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FIG. 35. Females. Age standard at 14 years 6 months. U n i o n is progressing in the metacarpal epiphyses. The radial epiphysis has developed a beak on the outerside t u r n i n g down towai'ds the shaft. T h e ulnar epiphysis is uniting. M u l t a n g u l u m minus is in close relationship with the saddle shaped end of metacarpal II.
SKELETAL MATURATION IN THE HAND IN AFRICAN CHILDREN
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FIG. 36. Females. Age standard at 15 years 6 months. U n i o n of all epiphyses is still progressing. T h e epiphyseal gap between the radial epiphysis and shaft has narrowed still further.
9.
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SKELETAL M A T U R A T I O N I N THE HAND I N AFRICAN C H I L D R E N
FIG. 38. Females. Age standard at 17 years 6 months. Fusion of metacarpal and phalangeal epiphyses is complete. T h e radial and ulnar epiphyses have not quite united with their shafts at their outer edges, otherwise the hand appears to be fully mature.