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A SIMPLE METHOD OF ONLAY BONE GRAFTING
1186
Relation of G.-6-P.D. Deficiency and Haemoglobin E Since haemoglobin E is prevalent in Thailand (NaNakorn et al. 1956) an attempt was made to determine whether there was any relation between the G.-6-P.D.deficiency trait and the heterozygous-E trait. This work was done only in Rayong, and only in boys. It was found that 13% of one hundred and thirty-six
subjects with haemoglobin A and 9% of thirty-three subjects with heterozygous E showed the enzyme deficiency. As far as could be ascertained from this limited number, therefore, there was no correlation between G.-6-P.D.-deficiency trait and hsemoglobin-E trait.
history of haemolysis was ever elicited. Moreover there evidence of blackwater fever. Thus the possible disadvantages of G.-6-P.D. deficiency so far as haemolysis
no
was no
is concerned were not demonstrated. Our results indicate that the G.-6-r.D.-deficient hemizygous Thai male does not appear to have any selective advantage so far as endemic malaria is concerned. In Thailand at any rate it seems that the deficiency of G.-6-P.D., as measured by the field test alone, may not be adequate to afford protection against malaria. Possibly other factors balance this abnormal gene in the Thai population exposed to endemic malaria. These factors are still unrevealed, and there is need for further investigation.
Discussion
The results indicate that at the age of 1-3 years in both endemic areas there is a significant increase in crude parasite-rates in carriers of the G.-6-P.D.-deficiency trait. This difference appears to be due to P. vivax preference of hemizygous enzyme-deficient males. No differences were noted so far as P. falciparum infections were concerned. Thus, the hemizygous G.-6-P.D.-deiicient male seems if anything more susceptible than normals to P. vivax infection, and is not protected against P. falciparum infection. The increase of P. vivax infection-rate in deficient subjects may be due to the known fact that P. vivax preferentially parasitises young red blood-cells, and an increase in the proportion of young red blood-cells in deficient subjects might be expected if they had had recurrent self-limited haemolysis and some associated reticulocytosis. However, since the comparison of parasite-densities in P. vivax infections between persons with normal enzyme content and those with deficient G.-6-P.D. showed no statistically significant difference, and since P. vivax is a self-limited infection, it is difficult to posit that G.-6-P.D.-deficient persons were in fact at a disadvantage. The differences in the figures are in any case small, and further evidence is needed to settle this
point. It must be emphasised that the screening test used here is not accurately quantitative, especially in those whose reaction-time is longer than 120 min. Possibly the parasite requires only a relatively small amount of enzyme, and a proportion of the group we have termed " deficient " as a result of the survey technique may, in fact, possess enough enzyme for the parasite but may nevertheless be indistinguishable by the dye-screening technique.
Latterly, Clyde (1961) have shown that African children, aged 1-3 years, appear to have a considerable degree of protection against P. falciparum malaria, at the significant level of 5%. Our results conflict with these findings so far as Thai children are concerned. It is possible that Allison’s subjects with decolorisationtimes greater than 120 min. may include a higher proportion of severely G.-6-P.D.-deficient subjects than was found in our series. We suggest that induced P. vivax and P. falciparum infection should be studied in non-immune persons with known quantitative levels of G.-6-P.D. in erythrocytes. The successive stages of infection and simultaneous changes of enzyme levels after the malarial infection themselves need more careful study. Primaquine is rarely used in Thailand, and the broad bean is not eaten. Most of our patients who had " fever " took small quantities of salicylates and phenacetin, but
Summary
Surveys of the prevalence of malaria and reactions to the dye-screening test for erythrocyte glucose-6-phosphate dehydrogenase were made in two endemic malaria areas in Thailand. The results indicate that the hemizygous male between ages 1-3 years is not protected against P. falciparum infection, and that he is more commonly infected with P. vivax (at 5% level of significance) than non-deficient individuals. The advantages and disadvantages associated with G.-6-P.D. deficiency in the people of Thailand are still unrevealed. We are grateful to Prof. B. G. Maegraith, who gave valuable advice this investigation; to Dr. Lek Suwanakul, director of the Rayong Hospital; to Dr. Somtasana Malikul, health officer in the malaria eradication programme, Nakorn Rajasrima; and to the members of staff in the School of Tropical Medicine and Endemic Diseases, Bangkok, whose help made this survey possible. on
REFERENCES
Allison, A. C. (1960) Nature, Lond. 186, 531. — Clyde, D. F. (1961) Brit. med. J. i, 1346. Gilles, H. M., Taylor, B. G. (1961) Ann. trop. Med. Parasit. 55, 64. Kidson, C. (1961) Nature, Lond. 190, 1120. Kruatrachue, M., Na-Nakorn, S., Charoenlarp, P., Suwanakul, L. (1961) Ann. trop. Med. Parasit. 55, 468. Marks, A., Johnson, A. B. (1958) J. clin. Invest. 37, 1542. Motulsky, A. G., Campbell, J. M. (1961) Blood (in the press). Na-Nakorn, S., Minich, V., Chernoff, A. I. (1956) J. Lab. clin. Med. 47, 490.
A SIMPLE METHOD OF ONLAY BONE GRAFTING ANDREW B. YOUNG F.R.C.S.E. SENIOR REGISTRAR
JOHN WHITE F.R.C.S.E.
Allison and
CONSULTANT SURGEON
From the
Department of Orthopœdic Surgery, Royal Infirmary, Glasgow
THE operation of bone grafting has been modified considerably through the years, since the first successful bone graft in man was performed in Glasgow by MacEwen in 1880. To provide firm fixation and apposition, without including metal, Albee (1915) devised the inlay graft, but the procedure was practicable only in the larger and more easily accessible bones, such as the tibia, and the degree of accuracy and precision required was very high. Because of these limitations, the large onlay graft became more popular (Campbell 1927), but it was only with the development of electrolytically inert metals which allowed screw fixation that the cortical onlay graft became permanently established (Campbell 1941). Today, many types of graft are used, each with its own particular
1187
Fig. 3-Bone graft in position.
Fig. I-Fracture site exposed and fixed with Sherman plate.
indications; but the onlay graft is still much used, and, in the forearm bones particularly, it is widely accepted as the method of choice. To cut and apply a cortical onlay graft to one of the long bones requires no outstanding surgical skill. There must be few surgeons, however, who, at some time, have not had the disappointing experience of breaking or cracking the graft, or of finding it not uniformly thick and therefore
fitting badly. On the principle that standard procedures should be as easy and trouble-free as possible, a method of cutting and
ficial cortex. Cuts are now made around the tibial plates with a power saw, and this enables the segment of tibia to be removed with the plate, to which it is firmly screwed. The extra rigidity given by the plate simplifies removal, and decreases the risk of damage to the graft. On separating the graft and plate we are left with a " bone plate " which corresponds exactly in length and position of screw holes to the plate already in position in the forearm (fig. 2). It is then a simple matter to remove the Sherman plates from the radius and ulna, and to replace them with the cortical grafts. To stop the screw-thread engaging in the graft the holes in the graft must be enlarged with a wider drill before it is fitted. This enables the graft to be drawn on to the cortex of the long bone (fig. 3).
When both bones of the forearm are grafted the interof piate and graft is simplicity itself because the other bone is firmly fixed by the initial plate when the interchange is taking place. Time can be saved if a second assistant is available; both procedures can then be done simultaneously, since only the selection of the size of the initial Sherman plate is needed for the graft to be taken from the tibia. One of the objections to onlay bone grafting of the humerus and femur is that the graft sometimes breaks during the fourth and fifth week. This can be prevented by leaving the template on the graft and not separating them as we have described. In this way the bone is fixed by the onlay graft augmented by the plate overlying it.
change
Fig. 2-Sherman plates and
"
fixing these grafts has been evolved at the Royal Infirmary, Glasgow, which we find simple, rapid, and accurate, and one that greatly decreases technical mishaps and misfits. Further, this method can be used with ease in places where specialist experience may not be readily available. The
Summary
bone plates ".
Technique
We describe a technique of onlay bone grafting which combines simplicity, speed, and accuracy. REFERENCES
Albee, F. H. (1915) Bone Graft Surgery; p. 149. Philadelphia. Campbell, W. C. (1927) Sth. med. J. 20, 107. Boyd, H. B. (1941) Amer. J. Surg. 51, 748. MacEwen, W. (1912) The Growth of Bone: Observations on Osteogenesis: Experimental Inquiry into the Development and Reproduction of Diaphyseal Bone; p. 180. Glasgow. —
The following description is of onlay grafting of the radius and ulna, but the technique is similar for all long
bones.
! ’
The radius and ulna are exposed in the usual way, and the surfaces are levelled to receive the grafts.Sherman ’ plates corresponding in length to the proposed grafts are screwed to the radius and ulna in the intended position of the grafts, with the screws penetrating both cortices (fig. 1). Next, the tibia is exposed subperiosteally, and Sherman plates, of the same size as those applied to the forearm bones, are fixed to the subcutaneous surface of the tibia by means of short screws, usually 3/8 ion., which penetrate only the super-
"... The main attributes of a crank are his powers of persuaown hypothesis, his knowledge of all the literature and incidents that can be made to support his hypothesis, his imagination, enthusiasm and apparent sincerity. He eliminates data that does not support his hypothesis by disbelief or by the introduction of another
sion, his unshakeable belief in his
and he is quite incapable of designing an experithat could show his hypothesis to be untrue."H. H. HOLMAN, D.SC., F.R.C.V.S. Biological Research Method. Edinburgh and London, 1962.
hypothesis, ment
Relation of G.-6-P.D. Deficiency and Haemoglobin E Since haemoglobin E is prevalent in Thailand (NaNakorn et al. 1956) an attempt was made to determine whether there was any relation between the G.-6-P.D.deficiency trait and the heterozygous-E trait. This work was done only in Rayong, and only in boys. It was found that 13% of one hundred and thirty-six
subjects with haemoglobin A and 9% of thirty-three subjects with heterozygous E showed the enzyme deficiency. As far as could be ascertained from this limited number, therefore, there was no correlation between G.-6-P.D.-deficiency trait and hsemoglobin-E trait.
history of haemolysis was ever elicited. Moreover there evidence of blackwater fever. Thus the possible disadvantages of G.-6-P.D. deficiency so far as haemolysis
no
was no
is concerned were not demonstrated. Our results indicate that the G.-6-r.D.-deficient hemizygous Thai male does not appear to have any selective advantage so far as endemic malaria is concerned. In Thailand at any rate it seems that the deficiency of G.-6-P.D., as measured by the field test alone, may not be adequate to afford protection against malaria. Possibly other factors balance this abnormal gene in the Thai population exposed to endemic malaria. These factors are still unrevealed, and there is need for further investigation.
Discussion
The results indicate that at the age of 1-3 years in both endemic areas there is a significant increase in crude parasite-rates in carriers of the G.-6-P.D.-deficiency trait. This difference appears to be due to P. vivax preference of hemizygous enzyme-deficient males. No differences were noted so far as P. falciparum infections were concerned. Thus, the hemizygous G.-6-P.D.-deiicient male seems if anything more susceptible than normals to P. vivax infection, and is not protected against P. falciparum infection. The increase of P. vivax infection-rate in deficient subjects may be due to the known fact that P. vivax preferentially parasitises young red blood-cells, and an increase in the proportion of young red blood-cells in deficient subjects might be expected if they had had recurrent self-limited haemolysis and some associated reticulocytosis. However, since the comparison of parasite-densities in P. vivax infections between persons with normal enzyme content and those with deficient G.-6-P.D. showed no statistically significant difference, and since P. vivax is a self-limited infection, it is difficult to posit that G.-6-P.D.-deficient persons were in fact at a disadvantage. The differences in the figures are in any case small, and further evidence is needed to settle this
point. It must be emphasised that the screening test used here is not accurately quantitative, especially in those whose reaction-time is longer than 120 min. Possibly the parasite requires only a relatively small amount of enzyme, and a proportion of the group we have termed " deficient " as a result of the survey technique may, in fact, possess enough enzyme for the parasite but may nevertheless be indistinguishable by the dye-screening technique.
Latterly, Clyde (1961) have shown that African children, aged 1-3 years, appear to have a considerable degree of protection against P. falciparum malaria, at the significant level of 5%. Our results conflict with these findings so far as Thai children are concerned. It is possible that Allison’s subjects with decolorisationtimes greater than 120 min. may include a higher proportion of severely G.-6-P.D.-deficient subjects than was found in our series. We suggest that induced P. vivax and P. falciparum infection should be studied in non-immune persons with known quantitative levels of G.-6-P.D. in erythrocytes. The successive stages of infection and simultaneous changes of enzyme levels after the malarial infection themselves need more careful study. Primaquine is rarely used in Thailand, and the broad bean is not eaten. Most of our patients who had " fever " took small quantities of salicylates and phenacetin, but
Summary
Surveys of the prevalence of malaria and reactions to the dye-screening test for erythrocyte glucose-6-phosphate dehydrogenase were made in two endemic malaria areas in Thailand. The results indicate that the hemizygous male between ages 1-3 years is not protected against P. falciparum infection, and that he is more commonly infected with P. vivax (at 5% level of significance) than non-deficient individuals. The advantages and disadvantages associated with G.-6-P.D. deficiency in the people of Thailand are still unrevealed. We are grateful to Prof. B. G. Maegraith, who gave valuable advice this investigation; to Dr. Lek Suwanakul, director of the Rayong Hospital; to Dr. Somtasana Malikul, health officer in the malaria eradication programme, Nakorn Rajasrima; and to the members of staff in the School of Tropical Medicine and Endemic Diseases, Bangkok, whose help made this survey possible. on
REFERENCES
Allison, A. C. (1960) Nature, Lond. 186, 531. — Clyde, D. F. (1961) Brit. med. J. i, 1346. Gilles, H. M., Taylor, B. G. (1961) Ann. trop. Med. Parasit. 55, 64. Kidson, C. (1961) Nature, Lond. 190, 1120. Kruatrachue, M., Na-Nakorn, S., Charoenlarp, P., Suwanakul, L. (1961) Ann. trop. Med. Parasit. 55, 468. Marks, A., Johnson, A. B. (1958) J. clin. Invest. 37, 1542. Motulsky, A. G., Campbell, J. M. (1961) Blood (in the press). Na-Nakorn, S., Minich, V., Chernoff, A. I. (1956) J. Lab. clin. Med. 47, 490.
A SIMPLE METHOD OF ONLAY BONE GRAFTING ANDREW B. YOUNG F.R.C.S.E. SENIOR REGISTRAR
JOHN WHITE F.R.C.S.E.
Allison and
CONSULTANT SURGEON
From the
Department of Orthopœdic Surgery, Royal Infirmary, Glasgow
THE operation of bone grafting has been modified considerably through the years, since the first successful bone graft in man was performed in Glasgow by MacEwen in 1880. To provide firm fixation and apposition, without including metal, Albee (1915) devised the inlay graft, but the procedure was practicable only in the larger and more easily accessible bones, such as the tibia, and the degree of accuracy and precision required was very high. Because of these limitations, the large onlay graft became more popular (Campbell 1927), but it was only with the development of electrolytically inert metals which allowed screw fixation that the cortical onlay graft became permanently established (Campbell 1941). Today, many types of graft are used, each with its own particular
1187
Fig. 3-Bone graft in position.
Fig. I-Fracture site exposed and fixed with Sherman plate.
indications; but the onlay graft is still much used, and, in the forearm bones particularly, it is widely accepted as the method of choice. To cut and apply a cortical onlay graft to one of the long bones requires no outstanding surgical skill. There must be few surgeons, however, who, at some time, have not had the disappointing experience of breaking or cracking the graft, or of finding it not uniformly thick and therefore
fitting badly. On the principle that standard procedures should be as easy and trouble-free as possible, a method of cutting and
ficial cortex. Cuts are now made around the tibial plates with a power saw, and this enables the segment of tibia to be removed with the plate, to which it is firmly screwed. The extra rigidity given by the plate simplifies removal, and decreases the risk of damage to the graft. On separating the graft and plate we are left with a " bone plate " which corresponds exactly in length and position of screw holes to the plate already in position in the forearm (fig. 2). It is then a simple matter to remove the Sherman plates from the radius and ulna, and to replace them with the cortical grafts. To stop the screw-thread engaging in the graft the holes in the graft must be enlarged with a wider drill before it is fitted. This enables the graft to be drawn on to the cortex of the long bone (fig. 3).
When both bones of the forearm are grafted the interof piate and graft is simplicity itself because the other bone is firmly fixed by the initial plate when the interchange is taking place. Time can be saved if a second assistant is available; both procedures can then be done simultaneously, since only the selection of the size of the initial Sherman plate is needed for the graft to be taken from the tibia. One of the objections to onlay bone grafting of the humerus and femur is that the graft sometimes breaks during the fourth and fifth week. This can be prevented by leaving the template on the graft and not separating them as we have described. In this way the bone is fixed by the onlay graft augmented by the plate overlying it.
change
Fig. 2-Sherman plates and
"
fixing these grafts has been evolved at the Royal Infirmary, Glasgow, which we find simple, rapid, and accurate, and one that greatly decreases technical mishaps and misfits. Further, this method can be used with ease in places where specialist experience may not be readily available. The
Summary
bone plates ".
Technique
We describe a technique of onlay bone grafting which combines simplicity, speed, and accuracy. REFERENCES
Albee, F. H. (1915) Bone Graft Surgery; p. 149. Philadelphia. Campbell, W. C. (1927) Sth. med. J. 20, 107. Boyd, H. B. (1941) Amer. J. Surg. 51, 748. MacEwen, W. (1912) The Growth of Bone: Observations on Osteogenesis: Experimental Inquiry into the Development and Reproduction of Diaphyseal Bone; p. 180. Glasgow. —
The following description is of onlay grafting of the radius and ulna, but the technique is similar for all long
bones.
! ’
The radius and ulna are exposed in the usual way, and the surfaces are levelled to receive the grafts.Sherman ’ plates corresponding in length to the proposed grafts are screwed to the radius and ulna in the intended position of the grafts, with the screws penetrating both cortices (fig. 1). Next, the tibia is exposed subperiosteally, and Sherman plates, of the same size as those applied to the forearm bones, are fixed to the subcutaneous surface of the tibia by means of short screws, usually 3/8 ion., which penetrate only the super-
"... The main attributes of a crank are his powers of persuaown hypothesis, his knowledge of all the literature and incidents that can be made to support his hypothesis, his imagination, enthusiasm and apparent sincerity. He eliminates data that does not support his hypothesis by disbelief or by the introduction of another
sion, his unshakeable belief in his
and he is quite incapable of designing an experithat could show his hypothesis to be untrue."H. H. HOLMAN, D.SC., F.R.C.V.S. Biological Research Method. Edinburgh and London, 1962.
hypothesis, ment