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The middle slip or boutonniere deformity in burned hands
THE MIDDLE SLIP OR BOUTONNIERE DEFORMITY IN BURNED HANDS
By D. O.
MAISELS,F.R.C.S.Ed.
Senior Registrar, Liverpool Region Burns and Plastic Unit, Whiston Hospital, Prescot, Lancashire THE clawed, virtually useless hand which may result from a severe dorsal burn is a tragedy which cannot be over-emphasised. A burn which, judged by its depth and extent, would amount to a trivial injury on any other part of the limbs or trunk can spell disaster for the future life and happiness of the patient if it affects the hands. There are two main groups of burns of the hand depending o n whether the dorsal or palmar surfaces are affected. The factors which account for the greater frequency of dorsal burns are : first, the dorsal surface is much more exposed to flashes, flames, and explosions; second, the usual reflex clutching of the hands in an emergency which protects the palms ; and third, the frequent holding up of the hands to shield the face which again exposes the dorsal surfaces. Palmar burns are usually the result of grasping hot objects and are far less frequently encountered. The deformities resulting from burns of the dorsum of the hand are well recognised and have been extensively described and discussed. After reviewing the literature, it seems, however, that the main weight of attention has been directed to the region proximal to the interphalangeal joints and that perhaps less attention than they deserve has been focused on these joints, and more particularly on their potential for recovery. Anatomy and Function.--It is not proposed to embark upon a full description of the anatomy and function of the structures on the dorsum of the hand and fingers. This has been most excellently done by Braithwaite et al. (I949), Landsmeer (I955, I958), Bunnell (I956), and Stack (I962), and while these writers differ on certain aspects of the function of the extensor complex, these differences do not appear to be sufficiently pertinent to the present problem to demand further consideration. Certain features though should be stressed. First, the skin of the dorsum of the hand and fingers is relatively thin and the subcutaneous tissue scant, with the result that the extensor mechanism, the joint capsules, and the joints themselves are particularly vulnerable to thermal injuries. Furthermore, the infection which may complicate a burn involving skin only can lead to secondary damage to deeper structures. Secondly, especially on the dorsum of the fingers, there is no excess of skin when the joints are flexed, and consequently cedema, contraction of eschar, and later, scar contracture, readily give rise to ischmmic changes in these deeper structures. The Middle Slip Deformity.--Division of the middle slip of the extensor expansion leads to the typical boutonniere deformity. This deformity is the result of the lateral bands being able to slip anteriorly where they then become 2 A
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flexors of the proximal interphalangeal joints. These joints adopt a position of hyperflexion and as the lateral bands contract and fibrose the distal interphalangeal joint is pulled into a position of hyperextension. Another factor in this deformity, as pointed out by Landsmeer (i958), is the disturbance of the equilibrium of the various components acting on the interphalangeal joints. Burns of the dorsum of the hand may either destroy the central slip primarily, or, as suggested above, infection or ischa:mic necrosis may do so secondarily. In either event, the typical deformity results and its mechanism as described above is accepted by almost all authorities. The notable exception is Gronley et al. (1962), who claim it is secondary to the hyperextension of the metacarpo-phalangeal joints which is seen in burns of the dorsum of the hand. The directly opposite view, i.e., that the deformity at the proximal interphalangeal joint which results from destruction of the middle slip, may in fact be a prominent factor in the hyperextension of the metacarpo-phalangeal joints is held by Braithwaite and Watson (1949) and is more probably correct. TREATMENT Prevention.--Although a good deal has been written about the prevention of deformities following dorsal burns of the hand, relatively little attention has been devoted specifically to the problem of the middle slip. To some extent this is of course due to the fact that it cannot be separated readily from the rest of the hand. For the early treatment of these burns there are opposing schools of thought. Trueta (1946) held that immobilisation in the position of function was absolutely essential if deformities were to be prevented. Mclndoe (I944), on the other hand, pioneered the use of active movements from the earliest possible moment in order to obtain the same ends. The hands were dressed and maintained in a " basic position," i.e., the position of function, between regular sessions of active movement. Only where there was extensive damage to tendons or joints did he advise immobilisation. Braithwaite and Watson (1949) felt that neither early movement nor immobilisation alone would prevent the development of deformities. They claimed that early excision of the slough and skin grafting, by reducing the amount of infection, granulation, and fibrosis with its resultant ischmmia, were vital to the prevention of deformities. In the main, this is certainly true. Moreover, this policy, carried to its logical conclusion which is primary excision and grafting of full-thickness burns, when applied to cases in which the deeper structures are spared, will prevent the development of secondary changes in these deeper structures. For a variety of reasons this optimal policy is not always possible but, when it is, excellent functional results are obtainable. Many of those who practise the exposure treatment of burns apply this method to burns of the hands as well (Wallace, 1949 ; Kyle and Wallace, 1950 ; Evans, 1953; Clarkson and Evans, 1954). Condon and Kaplan (1959) advised exposure and emphasised early movement to prevent deformities. They devised their " torque splint" to maintain moderate extension at the interphalangeal joints and so to avoid the ischmmic necrosis of the middle slip which may develop if these joints assume a position of acute flexion. A similar device is illustrated in a paper by Taylor (1953).
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Muir and Barclay (1962), while believing in the exposure method for most burns, prefer the closed method for hands. They stress the dangers of allowing (edematous tendons to remain stretched over Lhe dorsal aspects of the proximal interphalangeal joints where they may undergo ischmmic necrosis. These writers dress the hands on a splint with the metacarpo-phalangeal joints flexed to 8o degrees and the interphalangeal joints in almost complete extension, and they specifically mention that neglect of this precaution may lead to a boutonniere deformity. Treatment of the R u p t u r e d Middle Slip.--The treatment of middle slip deformities resulting from trauma other than burns is discussed extensively in the literature. In so far as it is relevant to burns, it will be mentioned here. The minimal amount of treatment is that of Learning et al. (I96O) who made no attempt to repair the middle slip " as this injury results in minimal loss of function." Entin (196o) advocates conservative treatment in the first instance with the metacarpo-phalangeal joints flexed and the interphalangeal joints extended. If seen within the first week, Bunnell (1956) suggests splinting for five weeks with both the metacarpo-phalangeal and the proximal interphalangeal joints in extension and the distal interphalangeal joint free. In cases of failed conservative treatment or if seen after a week several methods are described for the surgical repair or replacement of the middle slip. A remarkable approach to middle slip lacerations is that of Nemethi (I956), who advocated excision to convert the round hole resulting from button-holing into a longitudinal ellipse with two medio-lateral bands. He said that when executed properly no boutonniere deformity was produced but quoted no figures or results in his paper. Flatt (1962) has put forward a novel suggestion for the relief of the hyperflexion of the proximal interphalangeal joints in middle slip deformities resulting from rheumatoid arthritis. This entailed section of the insertion of the intrinsic bands. There is thus a considerable enthusiasm for a variety of reconstructive procedures for the ordinary traumatic and rheumatoid middle slip deformity. Burns, however, are complicated by two factors, first the frequent exposure of the proximal interphalangeal joint, and second the frequently poor quality of the skin cover after healing is complete. The first may lead to ankylosis of the joint and the second makes any reconstructive operation on the extensor mechanism extremely hazardous to say the least. For these reasons it is generally accepted that damage to the extensor mechanism, the joint capsule or the joint will inevitably lead to a fixed deformity with gross loss of function in the affected finger. Accordingly, most writers have stated that the chief objective of treatment in such cases should be bony fusion of the proximal interphalangeal joint in a position of slight flexion. Moncrieff (1958) suggested primary fusion of the joints immediately prior to attempting skin coverage. Braithwaite and Watson (1949) were in favour of splinting the proximal interphalangeal joints in the position of function until arthrodesis could be performed in about two to three months post-bum. Bunnell (1956) wrote " i f a finger joint be open, that part must be splinted in moderate flexion with the intention of obtaining ankylosis," and Robertson (1958), Craven and Duran (I96O), Rank and Wakefield (I96o), and Clarkson and Pelly (I962) among others agreed that in
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order to restore any functional use in the hand, b o n y ankylosis of the proximal interphalangeal joints in the position o f function was mandatory. ILLUSTRATIVE CASES
Case 1.--Mrs M. W. (Fig. I). This 53-year-old woman caught her left hand in a hot laundry press. She sustained full-thickness burns of the dorsum o f the index, middle, and ring fingers and the distal third of the lateral half of the hand, and a small patch on the little finger. At operation the same evening, primary excision of the burn was carried out. The paratenon on the extensor tendons was found to be intact and the defect was covered with
A
B C FIG. I Case I. A, Shows h a n d after grafting giving an indication of area burned. B and C, Show range of function ten weeks after burning.
a medium-thickness split-skin graft. The hand was immobilised with the metacarpophalangeal joints flexed to about 90 degrees and the interphalangeal joints extended. There was a complete take of the skin grafts and two weeks after burning she began active exercises. When seen ten weeks after burning she was back at work and managing without difficulty. She could get the finger-tips to the palm although flexion at the interphalangeal joints was not yet full. She had full extension with no suggestion of a middle slip deformity. Case 2.--Mrs M. W. (Fig. 2).
This 43-year-old woman sustained a hot press burn of the dorsum of the right hand. The burn, which affected the index, middle, and ring fingers and the adjacent part of the hand, was treated elsewhere as an out-patient. She was referred to this unit three weeks after burning with a moderately infected hand. At operation one week later the slough was removed and the paratenon on the index finger found to be intact. On the middle finger the FIG. 2 extensor tendon was exposed over the proximal interphalangeal joint and on the ring finger the Case 2. Six months after burning. Persistent middle slip deformity. ioint capsule was exposed. An abdominal flap was applied to the area and later divided. Six months after burning the patient had marked middle slip deformities of all three fingers and was unable to return to her work.
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Case 3 . - - M r s C. W. (Fig. 3). This patient was aged 17 when she was trapped in a burning house and sustained burns of the face, abdomen, buttocks, and dorsum of both hands and fingers. She was pregnant and was delivered three weeks after admission which delayed treatment of the hands. Five weeks after burning the dorsal surfaces of the hands were grafted. T h e grafts took well but she was reluctant to use the hands and prolonged rehabilitation was required. Three months after burning she had middle slip deformities of all fingers but a full range of active flexion. Straight splints were applied to the fingers leaving the metacarpophalangeal joints free, and these were retained for six weeks. This resulted in a marked improvement of the deformities which was maintained when last seen, one year after the injury. There was still slight hyperextension of the distal interphalangeal joints, but the proximal interphalangeal joints were all straight with the exception of the right index which still lacked 5 degrees of full extension.
A
B
C
D
FIG. 3 Case 3. A and B, Right and left hands three months after burning to show deformities. C, Shows full flexion at this time. D and E, The position after six weeks splinting. This has been maintained for nine months.
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~ i ~ i ~ i ~
E
~'~
,~
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Case 4 . - - M r W. T. (Fig. 4). This 3I-year-old fitter was involved in an explosion in a chemical factory. He sustained a zo per cent. burn of the face, thighs, arms, and dorsum of both hands and all fingers. T h e burns of the hands proved to be deep partialthickness burns which healed spontaneously except for small areas over the proximal interphalangeal joints of the left ring and right middle and little fingers where the extensor tendons became exposed. These areas did not become suitable for grafting before they had healed spontaneously seven weeks after burning.
FIG. 4 Case 4- A, Indicates deformity of left ring finger two months after burning. ]3 and C, The range of function after splinting. This has been maintained. I) and E, Right hand one year after burning.
T w o months after burning these three fingers all showed marked middle slip deformities. An " Odstock S p l i n t " (Glanville, I962) was applied to the left ring finger, and straight splints to the interphalangeal joints of the right middle and little fingers where the skin was less soundly healed. Within two weeks the left ring finger was completely corrected, and on the right hand within three weeks the deformities were almost completely corrected. T h e splints were retained full time for six weeks and at night only for a further two weeks on the left ring and right little fingers. A night
THE MIDDLE SLIP OR BOUTONNIERE
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splint was retained for many months on the right middle finger in an attempt to obtain complete correction. Six months after the accident the patient was managing his work as a fitter with no difficulty and virtually full function of his hands. Case 5.wMr D. S. (Fig. 5)- This 3o-year-old man sustained burns of his face, knees, and dorsum of hands in a "blow back" from a furnace. He was treated elsewhere and referred seven weeks later at which time the burns were all healed except for very small patches on the dorsum of the left index and little fingers, and a larger strip on the
A
B
Fro. 5 Case 5. A, Shortly after admission. 13, The position to which he relapsed on leaving off the splint. C,'Present position.
C ring finger. The ring finger showed a marked middle slip deformity with the proximal interphalangeal joint flexed to approximately 70 degrees. The raw areas healed very quickly with dressings and a straight splint, and two weeks later he had full extension of the proximal interphalangeal joint. He stopped using the splint and the deformity recurred. The splint was replaced and he rapidly recovered extension of the interphalangeal joint. He has worn a night splint only since he returned to work after a few weeks and manages without difficulty. There is a good range of flexion in the proximal interphalangeal joint but extension relapses somewhat by the later afternoon when it is short of Io to I5 degrees. Case 6.--Mrs J. R. (Fig. 6).
This 6o-year-old woman accidentally touched the hot
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element of an electric fire with her right hand. She sustained full-thickness burns affecting, in the main, the dorsal aspects of the middle, ring, and little fingers.
FIG. 6 Case 6. A, On admission. B, The deformity after four months. C~ The " Odstock " splint in use. D and E, The range of function after two months' splinting.
A
T h e burns were excised forty-eight hours after burning when the paratenon was found to be intact on the middle and little fingers. On the dorsum of the proximal interphalangeal joint of the ring finger the tendon was exposed. Accordingly, this finger was repaired with a local flap over the exposed tendon, the rest of the excised areas being covered with medium-thickness split-skin grafts. T h e hand healed well and she started active exercises eighteen days later. T h e ring finger developed a middle slip deformity with the proximal interphalangeal joint flexed to 7 ° degrees. There was slow improvement of this, but four months after the original
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injury the proximal interphalangeal joint still lacked Bo degrees of extension. At this point an" Odstock Splint" was fitted to the ring finger and within a month an additional 2o degrees of extension had been obtained. She continued to wear the splint at night only for another two months and was then lacking only 5 degrees of full extension at the proximal interphalangeal joint. Case 7.--Alto T. (Fig. 7). Ann was 5 when her nightdress caught fire resulting in extensive burns of the trunk, thighs, and both hands. The palmar surfaces sustained only partial-thickness burns, but on the dorsum of both hands and all fingers there was full-thickness destruction. Two weeks after burning the hands were desloughed and grafted. One week later the left hand was healed as was most of the right hand except for areas on the dorsum of the index, middle, and ring fingers. The proximal interphalangeal joint of the middle
A
B FIG. 7 Case 7- A and B, Show the range of function twenty months after a burn in which the proximal interphalangeal ioint of the middle finger was opened. finger was open. Further grafts were applied and by seven weeks after burning the hand was healed, although there were marked middle slip deformities of the index, middle, and ring fingers. She was provided with a splint to flex the metacarpophalangeal joints and extend the interphalangeal joints and wore this continuously for four weeks apart from periods of active exercises during the day. Four months after burning there was hypertrophic scarring of the hand but full function. When last seen, twenty months after burning, she had retained full function of the hand. Case 8.--David C. (Fig. 8). David was 8 when his clothes caught fire causing a 46 per cent. burn of which just over 20 per cent. was full thickness. This included the dorsum of both hands. T h e left healed after grafting with full function, but the burns in the right hand were more severe and at one time all the proximal interphalangeal joints were open. Eight weeks after burning the hand was completely healed, but he had the classical deformity consisting of hyperextended metacarpo-phalangeal joints and marked middle slip deformities of all fingers. The scar on the dorsum of the hand was excised including that on the fingers as far distally as the middle phalanx. The defect was covered with a thick split-skin graft and the hand immobilised in full flexion. The grafts took well except over the dorsum of the proximal interphalangeal joints of the middle and little fingers. These were regrafted and left rather indifferent cover in these areas. A year later the hand was well healed with full function at the metacarpophalangeal joints but marked middle slip deformities of all fingers. Since the proximal interphalangeal joints were not fused it was decided to attempt surgical correction of these deformities.
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The index finger was treated first, the approach being through a laterally based flap on the dorsum. The middle slip had been destroyed so the lateral bands were divided, crossed, and reattached. The skin flap did not survive and was replaced by a cross-finger flap. When this flap was divided, repair of the extensor mechanism on the ring finger was carried out at the same operation. On this occasion the approach was through an S-shaped incision. The radial lateral band was split longitudinally, the lateral half of the split band divided distally and then used as a ligature to wrap around the lateral
FIG. 8 Case 8. A and B, Show the deformity. C and D, Show the range of function after repair of the middle slips to ring and index fingers.
bands, binding them together over the dorsum of the proximal interphalangeal joint. The repaired fingers were splinted with the interphalangeal joints extended for six weeks and a very gratifying result was obtained. A year later he had full flexion of the proximal interphalangeal joints and almost full extension. At this stage an attempt was made to repair the middle and little fingers, but despite division of the lateral bands and anterior capsule slides it was impossible to obtain more than I5 o degrees extension at the proximal interphalangeal joints. It was therefore decided to arthrodese the joints in the position of function. Case 9.--Mrs W. McK. (Fig. 9). This 29-year-old woman attempted to commit suicide by pouring para~_n on her clothing and then setting it alight. She sustained a 35 per cent. burn, the majority of it being full thickness and involving the trunk, face, arms, and hands. The dorsum of the hands was very deeply burned and all the proximal interphalangeal joints were opened. Both hands developed marked dorsal contractures a n d middle slip deformities and the proximal interphalangeal joints fused in hyperflexion.
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On the left hand the dorsal contractures were released by scar excisions and split-skin grafts, but because of the hyperflexion of the proximal interphalangeal joints, the hand was virtually useless. The fused joints were therefore excised and arthrodesed in the
A
B Fro. 9 Case 9- A, The deformityof left hand. B, After arthrodesis of the proximal interphalangealjoints. poskion of function which has resuked in a pronounced improvement in the function of the hand. The right hand has been released by scar excisions and grafting and also by capsulotomies to the metacarpo-phalangeal joints of the ring and little fingers. Excision and arthrodesis of the proximal interphalangeal joints in the position of function has recently been carried out. DISCUSSION These cases would seem to illustrate a progressive severity of damage to the extensor mechanism, capsule, and joints, and what can be achieved in the way of prevention and correction of the middle slip deformity resulting from burns. Cases I and 2 show the benefits to be obtained from primary excision and grafting. While it is impossible to be sure of the depth of damage in Case 2, it would seem reasonable to assume from the similarity of the age and sex of the patients and the cause of the burns that these two cases were as similar as any two burns ever are. A comparison of the relative merits of the methods advocated by Condon and Kaplan (1959) on the one hand and Muir and Barclay (1962) on the other is difficult in the absence of any large controlled series. Certainly both schools have advanced forceful and logical arguments, though it would appear that there is an inherent danger in the first method of obtaining loss of flexion in the metacarpophalangeal joints. Cases 3 to 6 illustrate the fact that the middle slip deformity resulting from burns is not invariably permanent and may on occasions lend itself quite readily to simple conservative methods of treatment. It is interesting to speculate on the pathogenesis of this particular variant of the deformity. Three possibilities occur. In the first place the deformity may be entirely functional in origin, i.e., the extensor expansion has sustained no mechanical damage. It is widely recognised that the function of the whole extensor complex as well as the flexors is an intricately balanced mechanism and that interference with any part of the whole results in failure of co-ordination and a multiplicity of deformities. Could this be an
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example of such loss of co-ordination ? If it is, and I have found no reference to it in the literature, an explanation of the parts played by the various components will be most difficult and complicated. Secondly, the deformity may result not so much from destruction of the middle slip and the transverse interlacing fibres as from their stretching in a manner analogous to that seen in rheumatoid arthritis (Flatt, I962). This is perhaps the first stage in the process of destruction which follows infection and ischmmia and if arrested and the joint splinted in extension it would appear to be reversible. The third possibility is that while there has been actual destruction of the middle slip, by splinting the joint in extension one allows the gap to become filled with scar tissue which when fully matured contracts sufficiently to replace the loss. Some support to this last theory is lent by Case 7. There is no doubt that in the ring finger at least where the joint was open, there must have been destruction of the middle slip. The present excellent function of this finger without surgical repair or replacement of the tendon can only be explained on the basis of organisation of scar tissue. Case 8 is an example of the possibility of carrying out late surgical repair of the middle slip following its destruction as a result of a burn. It~emphasises what has already been referred to, i.e., the poor skin cover on these fingers which will often require replacement. Bunnell (I956) quotes a case in which the skin cover was satisfactory and in which Fowler's operation proved successful, but I have found no other reference to surgical repair of this condition resulting from burns. Case 9 is a straightforward example of the fully developed, irreversible deformity in which arthrodesis in a better position is indicated. No other course is available, unless one were to consider joint replacement by a prosthesis (Flatt, r962 ) or joint transplantation (Erdelyi, I963). This would entail extensive skin replacement and tendon repairs and on balance would seem to be unjustifiably complex to achieve the relatively small advantage a successful result would have over a simple arthrodesis. CONCLUSIONS It becomes apparent that a uniformly gloomy prognosis for burns affecting the extensor mechanism of the fingers is unwarranted. Even the exposure of the proximal interphalangeal joints may on occasion be followed by a return to full function. Measures aimed at obtaining bony ankylosis of these joints in the early stages of treatment would seem to be unjustified and should be undertaken only when efforts to obtain a functional, mobile joint have failed. In the patient who is unable to co-operate in hand movements by reason of age or other factors, for example, extensive severe burns of other parts of the body, Muir and Barclay's (I962) closed method of treatment would seem best. In patients who are capable of co-operating there is a good case for the open method of treatment. The developed middle slip deformity is amenable in many cases to successful treatment by simple conservative methods, and very occasionally to surgical repair. These cases were admitted under the care of M r A. H. M. Littlewood and M r L. B. Scott, to whom I am grateful for permission to publish. The success obtained in Case 8 is attributable to M r A. H. M. Littlewood who operated on the index finger himself and encouraged me to treat the ring finger. I am indebted to him
THE MIDDLE
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HANDS
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f o r his help and encouragement in the preparation of this paper and also to M r R. P. Osborne f o r his constructive criticism of the manuscript. M y thanks are also due to M r R. R. Green for the photographs.
REFERENCES BRAITHWAITE, F., CHAr~NELL, G. D., MOORE, F. T., and WHILLIS, J. (1949). Brit. ft. plast. Surg., 2, 175. BRAITHWAITE,F., and WATSON, J. (1949). Brit. ft. Plast. Surg., 2, 21. BUI'ZlqELL,S. (1956). " Surgery of the Hand," 3rd ed. Philadelphia : Lippincott. CLARKSON,P., and EVANS, A. J. (1954). Med. Press, 232, 537. CLARKSON, P., and PELLY, A. (1952). " The General and Plastic Surgery of the Hand." Oxford : BlackweU Scientific Publications. Com3oI% K. C., and KAI'LAI~I,I. J. (1959). Brit. ft. plast. Surg., I2, 129. CRAVEN, R. E., and DIIRAI%R. J. (196o), Amer..7. Surg. xoo, 802. ENTIN, M. A. (196o). Surg. Clin. N. Amer., 40, 275. Em3ELYI, R. (1963). Plast. reconstr. Surg., 3 x, 14o. EVANS, A. J. (1953). Brit. J. plast. Surg., $, 263. FLATT, A. E. (1962). Ann. Roy. Coll. Surg. Engl., 3I, 279. GLANVlLLE, H. J. (1962). Lancet, i, 252. GRONLEY, J. K., YEAKEL,M. H., and GRANT, A. E. (1962). Arch. phys. Med., 43, 508. KYLE, M. J., and WALLACE,A. B. (195o). Brit. ft. plast. Surg., 3, 144. LANDSMEER,J. M. F. (1955). Acta anat. (Basel). Suppl. 24, 2, and vol. 25. -(1958). Acta. morph, neerl, scand., 2, 59. LEAMING, D. B., WALDER, D. N., and BRAITHWAITE,F. (196o). Brit. ft. Surg., 48, 247. Mclm~OE, R. H. (1944). Med. Press, 21i, 57. MONCRIEFE, J. A. (1958). Amer. ft. Surg., 96, 535. MUIR, I. F. K., and BARCLAY,T. L. (1962). " Burns and their Treatment." London : Lloyd Luke. NEMETHI, C. E. (1956). lndustr. Med. Surg., 25, 113. RANK, B. K., and WAKEFIELD, A. R. (196o). " Surgery of Repair as applied to Hand Injuries." Edinburgh : E. & S. Livingstone. ROBERTSON,D. C. (1958)..7. Bone fit. Surg., 4oA, 625. STACK, H. G. (1962). ft. Bone fit. Surg., 44 B, 899. TAYLOR, D. G. (1953). Brit. ft. plast. Surg., 5, 275. TRUETA, J. (1946). " The Principles and Practice of War Surgery," 3rd ed. London : Win. Heinemann. WALLACE,A. B. (1949). Brit. ft. plast. Surg., x, 232.
By D. O.
MAISELS,F.R.C.S.Ed.
Senior Registrar, Liverpool Region Burns and Plastic Unit, Whiston Hospital, Prescot, Lancashire THE clawed, virtually useless hand which may result from a severe dorsal burn is a tragedy which cannot be over-emphasised. A burn which, judged by its depth and extent, would amount to a trivial injury on any other part of the limbs or trunk can spell disaster for the future life and happiness of the patient if it affects the hands. There are two main groups of burns of the hand depending o n whether the dorsal or palmar surfaces are affected. The factors which account for the greater frequency of dorsal burns are : first, the dorsal surface is much more exposed to flashes, flames, and explosions; second, the usual reflex clutching of the hands in an emergency which protects the palms ; and third, the frequent holding up of the hands to shield the face which again exposes the dorsal surfaces. Palmar burns are usually the result of grasping hot objects and are far less frequently encountered. The deformities resulting from burns of the dorsum of the hand are well recognised and have been extensively described and discussed. After reviewing the literature, it seems, however, that the main weight of attention has been directed to the region proximal to the interphalangeal joints and that perhaps less attention than they deserve has been focused on these joints, and more particularly on their potential for recovery. Anatomy and Function.--It is not proposed to embark upon a full description of the anatomy and function of the structures on the dorsum of the hand and fingers. This has been most excellently done by Braithwaite et al. (I949), Landsmeer (I955, I958), Bunnell (I956), and Stack (I962), and while these writers differ on certain aspects of the function of the extensor complex, these differences do not appear to be sufficiently pertinent to the present problem to demand further consideration. Certain features though should be stressed. First, the skin of the dorsum of the hand and fingers is relatively thin and the subcutaneous tissue scant, with the result that the extensor mechanism, the joint capsules, and the joints themselves are particularly vulnerable to thermal injuries. Furthermore, the infection which may complicate a burn involving skin only can lead to secondary damage to deeper structures. Secondly, especially on the dorsum of the fingers, there is no excess of skin when the joints are flexed, and consequently cedema, contraction of eschar, and later, scar contracture, readily give rise to ischmmic changes in these deeper structures. The Middle Slip Deformity.--Division of the middle slip of the extensor expansion leads to the typical boutonniere deformity. This deformity is the result of the lateral bands being able to slip anteriorly where they then become 2 A
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flexors of the proximal interphalangeal joints. These joints adopt a position of hyperflexion and as the lateral bands contract and fibrose the distal interphalangeal joint is pulled into a position of hyperextension. Another factor in this deformity, as pointed out by Landsmeer (i958), is the disturbance of the equilibrium of the various components acting on the interphalangeal joints. Burns of the dorsum of the hand may either destroy the central slip primarily, or, as suggested above, infection or ischa:mic necrosis may do so secondarily. In either event, the typical deformity results and its mechanism as described above is accepted by almost all authorities. The notable exception is Gronley et al. (1962), who claim it is secondary to the hyperextension of the metacarpo-phalangeal joints which is seen in burns of the dorsum of the hand. The directly opposite view, i.e., that the deformity at the proximal interphalangeal joint which results from destruction of the middle slip, may in fact be a prominent factor in the hyperextension of the metacarpo-phalangeal joints is held by Braithwaite and Watson (1949) and is more probably correct. TREATMENT Prevention.--Although a good deal has been written about the prevention of deformities following dorsal burns of the hand, relatively little attention has been devoted specifically to the problem of the middle slip. To some extent this is of course due to the fact that it cannot be separated readily from the rest of the hand. For the early treatment of these burns there are opposing schools of thought. Trueta (1946) held that immobilisation in the position of function was absolutely essential if deformities were to be prevented. Mclndoe (I944), on the other hand, pioneered the use of active movements from the earliest possible moment in order to obtain the same ends. The hands were dressed and maintained in a " basic position," i.e., the position of function, between regular sessions of active movement. Only where there was extensive damage to tendons or joints did he advise immobilisation. Braithwaite and Watson (1949) felt that neither early movement nor immobilisation alone would prevent the development of deformities. They claimed that early excision of the slough and skin grafting, by reducing the amount of infection, granulation, and fibrosis with its resultant ischmmia, were vital to the prevention of deformities. In the main, this is certainly true. Moreover, this policy, carried to its logical conclusion which is primary excision and grafting of full-thickness burns, when applied to cases in which the deeper structures are spared, will prevent the development of secondary changes in these deeper structures. For a variety of reasons this optimal policy is not always possible but, when it is, excellent functional results are obtainable. Many of those who practise the exposure treatment of burns apply this method to burns of the hands as well (Wallace, 1949 ; Kyle and Wallace, 1950 ; Evans, 1953; Clarkson and Evans, 1954). Condon and Kaplan (1959) advised exposure and emphasised early movement to prevent deformities. They devised their " torque splint" to maintain moderate extension at the interphalangeal joints and so to avoid the ischmmic necrosis of the middle slip which may develop if these joints assume a position of acute flexion. A similar device is illustrated in a paper by Taylor (1953).
THE MIDDLE SLIP OR BOUTONNIERE
DEFORMITY
IN BURNED HANDS
119
Muir and Barclay (1962), while believing in the exposure method for most burns, prefer the closed method for hands. They stress the dangers of allowing (edematous tendons to remain stretched over Lhe dorsal aspects of the proximal interphalangeal joints where they may undergo ischmmic necrosis. These writers dress the hands on a splint with the metacarpo-phalangeal joints flexed to 8o degrees and the interphalangeal joints in almost complete extension, and they specifically mention that neglect of this precaution may lead to a boutonniere deformity. Treatment of the R u p t u r e d Middle Slip.--The treatment of middle slip deformities resulting from trauma other than burns is discussed extensively in the literature. In so far as it is relevant to burns, it will be mentioned here. The minimal amount of treatment is that of Learning et al. (I96O) who made no attempt to repair the middle slip " as this injury results in minimal loss of function." Entin (196o) advocates conservative treatment in the first instance with the metacarpo-phalangeal joints flexed and the interphalangeal joints extended. If seen within the first week, Bunnell (1956) suggests splinting for five weeks with both the metacarpo-phalangeal and the proximal interphalangeal joints in extension and the distal interphalangeal joint free. In cases of failed conservative treatment or if seen after a week several methods are described for the surgical repair or replacement of the middle slip. A remarkable approach to middle slip lacerations is that of Nemethi (I956), who advocated excision to convert the round hole resulting from button-holing into a longitudinal ellipse with two medio-lateral bands. He said that when executed properly no boutonniere deformity was produced but quoted no figures or results in his paper. Flatt (1962) has put forward a novel suggestion for the relief of the hyperflexion of the proximal interphalangeal joints in middle slip deformities resulting from rheumatoid arthritis. This entailed section of the insertion of the intrinsic bands. There is thus a considerable enthusiasm for a variety of reconstructive procedures for the ordinary traumatic and rheumatoid middle slip deformity. Burns, however, are complicated by two factors, first the frequent exposure of the proximal interphalangeal joint, and second the frequently poor quality of the skin cover after healing is complete. The first may lead to ankylosis of the joint and the second makes any reconstructive operation on the extensor mechanism extremely hazardous to say the least. For these reasons it is generally accepted that damage to the extensor mechanism, the joint capsule or the joint will inevitably lead to a fixed deformity with gross loss of function in the affected finger. Accordingly, most writers have stated that the chief objective of treatment in such cases should be bony fusion of the proximal interphalangeal joint in a position of slight flexion. Moncrieff (1958) suggested primary fusion of the joints immediately prior to attempting skin coverage. Braithwaite and Watson (1949) were in favour of splinting the proximal interphalangeal joints in the position of function until arthrodesis could be performed in about two to three months post-bum. Bunnell (1956) wrote " i f a finger joint be open, that part must be splinted in moderate flexion with the intention of obtaining ankylosis," and Robertson (1958), Craven and Duran (I96O), Rank and Wakefield (I96o), and Clarkson and Pelly (I962) among others agreed that in
I20
B R I T I S H JOURNAL OF PLASTIC SURGERY
order to restore any functional use in the hand, b o n y ankylosis of the proximal interphalangeal joints in the position o f function was mandatory. ILLUSTRATIVE CASES
Case 1.--Mrs M. W. (Fig. I). This 53-year-old woman caught her left hand in a hot laundry press. She sustained full-thickness burns of the dorsum o f the index, middle, and ring fingers and the distal third of the lateral half of the hand, and a small patch on the little finger. At operation the same evening, primary excision of the burn was carried out. The paratenon on the extensor tendons was found to be intact and the defect was covered with
A
B C FIG. I Case I. A, Shows h a n d after grafting giving an indication of area burned. B and C, Show range of function ten weeks after burning.
a medium-thickness split-skin graft. The hand was immobilised with the metacarpophalangeal joints flexed to about 90 degrees and the interphalangeal joints extended. There was a complete take of the skin grafts and two weeks after burning she began active exercises. When seen ten weeks after burning she was back at work and managing without difficulty. She could get the finger-tips to the palm although flexion at the interphalangeal joints was not yet full. She had full extension with no suggestion of a middle slip deformity. Case 2.--Mrs M. W. (Fig. 2).
This 43-year-old woman sustained a hot press burn of the dorsum of the right hand. The burn, which affected the index, middle, and ring fingers and the adjacent part of the hand, was treated elsewhere as an out-patient. She was referred to this unit three weeks after burning with a moderately infected hand. At operation one week later the slough was removed and the paratenon on the index finger found to be intact. On the middle finger the FIG. 2 extensor tendon was exposed over the proximal interphalangeal joint and on the ring finger the Case 2. Six months after burning. Persistent middle slip deformity. ioint capsule was exposed. An abdominal flap was applied to the area and later divided. Six months after burning the patient had marked middle slip deformities of all three fingers and was unable to return to her work.
THE MIDDLE SLIP OR BOUTONNIERE DEFORMITY IN BURNED HANDS
I2I
Case 3 . - - M r s C. W. (Fig. 3). This patient was aged 17 when she was trapped in a burning house and sustained burns of the face, abdomen, buttocks, and dorsum of both hands and fingers. She was pregnant and was delivered three weeks after admission which delayed treatment of the hands. Five weeks after burning the dorsal surfaces of the hands were grafted. T h e grafts took well but she was reluctant to use the hands and prolonged rehabilitation was required. Three months after burning she had middle slip deformities of all fingers but a full range of active flexion. Straight splints were applied to the fingers leaving the metacarpophalangeal joints free, and these were retained for six weeks. This resulted in a marked improvement of the deformities which was maintained when last seen, one year after the injury. There was still slight hyperextension of the distal interphalangeal joints, but the proximal interphalangeal joints were all straight with the exception of the right index which still lacked 5 degrees of full extension.
A
B
C
D
FIG. 3 Case 3. A and B, Right and left hands three months after burning to show deformities. C, Shows full flexion at this time. D and E, The position after six weeks splinting. This has been maintained for nine months.
~i~i~;~
~ i ~ i ~ i ~
E
~'~
,~
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BRITISH JOURNAL OF PLASTIC SURGERY
Case 4 . - - M r W. T. (Fig. 4). This 3I-year-old fitter was involved in an explosion in a chemical factory. He sustained a zo per cent. burn of the face, thighs, arms, and dorsum of both hands and all fingers. T h e burns of the hands proved to be deep partialthickness burns which healed spontaneously except for small areas over the proximal interphalangeal joints of the left ring and right middle and little fingers where the extensor tendons became exposed. These areas did not become suitable for grafting before they had healed spontaneously seven weeks after burning.
FIG. 4 Case 4- A, Indicates deformity of left ring finger two months after burning. ]3 and C, The range of function after splinting. This has been maintained. I) and E, Right hand one year after burning.
T w o months after burning these three fingers all showed marked middle slip deformities. An " Odstock S p l i n t " (Glanville, I962) was applied to the left ring finger, and straight splints to the interphalangeal joints of the right middle and little fingers where the skin was less soundly healed. Within two weeks the left ring finger was completely corrected, and on the right hand within three weeks the deformities were almost completely corrected. T h e splints were retained full time for six weeks and at night only for a further two weeks on the left ring and right little fingers. A night
THE MIDDLE SLIP OR BOUTONNIERE
DEFORMITY
IN BURNED HANDS
12 3
splint was retained for many months on the right middle finger in an attempt to obtain complete correction. Six months after the accident the patient was managing his work as a fitter with no difficulty and virtually full function of his hands. Case 5.wMr D. S. (Fig. 5)- This 3o-year-old man sustained burns of his face, knees, and dorsum of hands in a "blow back" from a furnace. He was treated elsewhere and referred seven weeks later at which time the burns were all healed except for very small patches on the dorsum of the left index and little fingers, and a larger strip on the
A
B
Fro. 5 Case 5. A, Shortly after admission. 13, The position to which he relapsed on leaving off the splint. C,'Present position.
C ring finger. The ring finger showed a marked middle slip deformity with the proximal interphalangeal joint flexed to approximately 70 degrees. The raw areas healed very quickly with dressings and a straight splint, and two weeks later he had full extension of the proximal interphalangeal joint. He stopped using the splint and the deformity recurred. The splint was replaced and he rapidly recovered extension of the interphalangeal joint. He has worn a night splint only since he returned to work after a few weeks and manages without difficulty. There is a good range of flexion in the proximal interphalangeal joint but extension relapses somewhat by the later afternoon when it is short of Io to I5 degrees. Case 6.--Mrs J. R. (Fig. 6).
This 6o-year-old woman accidentally touched the hot
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element of an electric fire with her right hand. She sustained full-thickness burns affecting, in the main, the dorsal aspects of the middle, ring, and little fingers.
FIG. 6 Case 6. A, On admission. B, The deformity after four months. C~ The " Odstock " splint in use. D and E, The range of function after two months' splinting.
A
T h e burns were excised forty-eight hours after burning when the paratenon was found to be intact on the middle and little fingers. On the dorsum of the proximal interphalangeal joint of the ring finger the tendon was exposed. Accordingly, this finger was repaired with a local flap over the exposed tendon, the rest of the excised areas being covered with medium-thickness split-skin grafts. T h e hand healed well and she started active exercises eighteen days later. T h e ring finger developed a middle slip deformity with the proximal interphalangeal joint flexed to 7 ° degrees. There was slow improvement of this, but four months after the original
THE MIDDLE SLIP OR BOUTONNIERE DEFORMITY IN BURNED HANDS
125
injury the proximal interphalangeal joint still lacked Bo degrees of extension. At this point an" Odstock Splint" was fitted to the ring finger and within a month an additional 2o degrees of extension had been obtained. She continued to wear the splint at night only for another two months and was then lacking only 5 degrees of full extension at the proximal interphalangeal joint. Case 7.--Alto T. (Fig. 7). Ann was 5 when her nightdress caught fire resulting in extensive burns of the trunk, thighs, and both hands. The palmar surfaces sustained only partial-thickness burns, but on the dorsum of both hands and all fingers there was full-thickness destruction. Two weeks after burning the hands were desloughed and grafted. One week later the left hand was healed as was most of the right hand except for areas on the dorsum of the index, middle, and ring fingers. The proximal interphalangeal joint of the middle
A
B FIG. 7 Case 7- A and B, Show the range of function twenty months after a burn in which the proximal interphalangeal ioint of the middle finger was opened. finger was open. Further grafts were applied and by seven weeks after burning the hand was healed, although there were marked middle slip deformities of the index, middle, and ring fingers. She was provided with a splint to flex the metacarpophalangeal joints and extend the interphalangeal joints and wore this continuously for four weeks apart from periods of active exercises during the day. Four months after burning there was hypertrophic scarring of the hand but full function. When last seen, twenty months after burning, she had retained full function of the hand. Case 8.--David C. (Fig. 8). David was 8 when his clothes caught fire causing a 46 per cent. burn of which just over 20 per cent. was full thickness. This included the dorsum of both hands. T h e left healed after grafting with full function, but the burns in the right hand were more severe and at one time all the proximal interphalangeal joints were open. Eight weeks after burning the hand was completely healed, but he had the classical deformity consisting of hyperextended metacarpo-phalangeal joints and marked middle slip deformities of all fingers. The scar on the dorsum of the hand was excised including that on the fingers as far distally as the middle phalanx. The defect was covered with a thick split-skin graft and the hand immobilised in full flexion. The grafts took well except over the dorsum of the proximal interphalangeal joints of the middle and little fingers. These were regrafted and left rather indifferent cover in these areas. A year later the hand was well healed with full function at the metacarpophalangeal joints but marked middle slip deformities of all fingers. Since the proximal interphalangeal joints were not fused it was decided to attempt surgical correction of these deformities.
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The index finger was treated first, the approach being through a laterally based flap on the dorsum. The middle slip had been destroyed so the lateral bands were divided, crossed, and reattached. The skin flap did not survive and was replaced by a cross-finger flap. When this flap was divided, repair of the extensor mechanism on the ring finger was carried out at the same operation. On this occasion the approach was through an S-shaped incision. The radial lateral band was split longitudinally, the lateral half of the split band divided distally and then used as a ligature to wrap around the lateral
FIG. 8 Case 8. A and B, Show the deformity. C and D, Show the range of function after repair of the middle slips to ring and index fingers.
bands, binding them together over the dorsum of the proximal interphalangeal joint. The repaired fingers were splinted with the interphalangeal joints extended for six weeks and a very gratifying result was obtained. A year later he had full flexion of the proximal interphalangeal joints and almost full extension. At this stage an attempt was made to repair the middle and little fingers, but despite division of the lateral bands and anterior capsule slides it was impossible to obtain more than I5 o degrees extension at the proximal interphalangeal joints. It was therefore decided to arthrodese the joints in the position of function. Case 9.--Mrs W. McK. (Fig. 9). This 29-year-old woman attempted to commit suicide by pouring para~_n on her clothing and then setting it alight. She sustained a 35 per cent. burn, the majority of it being full thickness and involving the trunk, face, arms, and hands. The dorsum of the hands was very deeply burned and all the proximal interphalangeal joints were opened. Both hands developed marked dorsal contractures a n d middle slip deformities and the proximal interphalangeal joints fused in hyperflexion.
THE
MIDDLE
SLIP
OR BOUTONNIERE
DEFORMITY
IN
BURNED
HANDS
127
On the left hand the dorsal contractures were released by scar excisions and split-skin grafts, but because of the hyperflexion of the proximal interphalangeal joints, the hand was virtually useless. The fused joints were therefore excised and arthrodesed in the
A
B Fro. 9 Case 9- A, The deformityof left hand. B, After arthrodesis of the proximal interphalangealjoints. poskion of function which has resuked in a pronounced improvement in the function of the hand. The right hand has been released by scar excisions and grafting and also by capsulotomies to the metacarpo-phalangeal joints of the ring and little fingers. Excision and arthrodesis of the proximal interphalangeal joints in the position of function has recently been carried out. DISCUSSION These cases would seem to illustrate a progressive severity of damage to the extensor mechanism, capsule, and joints, and what can be achieved in the way of prevention and correction of the middle slip deformity resulting from burns. Cases I and 2 show the benefits to be obtained from primary excision and grafting. While it is impossible to be sure of the depth of damage in Case 2, it would seem reasonable to assume from the similarity of the age and sex of the patients and the cause of the burns that these two cases were as similar as any two burns ever are. A comparison of the relative merits of the methods advocated by Condon and Kaplan (1959) on the one hand and Muir and Barclay (1962) on the other is difficult in the absence of any large controlled series. Certainly both schools have advanced forceful and logical arguments, though it would appear that there is an inherent danger in the first method of obtaining loss of flexion in the metacarpophalangeal joints. Cases 3 to 6 illustrate the fact that the middle slip deformity resulting from burns is not invariably permanent and may on occasions lend itself quite readily to simple conservative methods of treatment. It is interesting to speculate on the pathogenesis of this particular variant of the deformity. Three possibilities occur. In the first place the deformity may be entirely functional in origin, i.e., the extensor expansion has sustained no mechanical damage. It is widely recognised that the function of the whole extensor complex as well as the flexors is an intricately balanced mechanism and that interference with any part of the whole results in failure of co-ordination and a multiplicity of deformities. Could this be an
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example of such loss of co-ordination ? If it is, and I have found no reference to it in the literature, an explanation of the parts played by the various components will be most difficult and complicated. Secondly, the deformity may result not so much from destruction of the middle slip and the transverse interlacing fibres as from their stretching in a manner analogous to that seen in rheumatoid arthritis (Flatt, I962). This is perhaps the first stage in the process of destruction which follows infection and ischmmia and if arrested and the joint splinted in extension it would appear to be reversible. The third possibility is that while there has been actual destruction of the middle slip, by splinting the joint in extension one allows the gap to become filled with scar tissue which when fully matured contracts sufficiently to replace the loss. Some support to this last theory is lent by Case 7. There is no doubt that in the ring finger at least where the joint was open, there must have been destruction of the middle slip. The present excellent function of this finger without surgical repair or replacement of the tendon can only be explained on the basis of organisation of scar tissue. Case 8 is an example of the possibility of carrying out late surgical repair of the middle slip following its destruction as a result of a burn. It~emphasises what has already been referred to, i.e., the poor skin cover on these fingers which will often require replacement. Bunnell (I956) quotes a case in which the skin cover was satisfactory and in which Fowler's operation proved successful, but I have found no other reference to surgical repair of this condition resulting from burns. Case 9 is a straightforward example of the fully developed, irreversible deformity in which arthrodesis in a better position is indicated. No other course is available, unless one were to consider joint replacement by a prosthesis (Flatt, r962 ) or joint transplantation (Erdelyi, I963). This would entail extensive skin replacement and tendon repairs and on balance would seem to be unjustifiably complex to achieve the relatively small advantage a successful result would have over a simple arthrodesis. CONCLUSIONS It becomes apparent that a uniformly gloomy prognosis for burns affecting the extensor mechanism of the fingers is unwarranted. Even the exposure of the proximal interphalangeal joints may on occasion be followed by a return to full function. Measures aimed at obtaining bony ankylosis of these joints in the early stages of treatment would seem to be unjustified and should be undertaken only when efforts to obtain a functional, mobile joint have failed. In the patient who is unable to co-operate in hand movements by reason of age or other factors, for example, extensive severe burns of other parts of the body, Muir and Barclay's (I962) closed method of treatment would seem best. In patients who are capable of co-operating there is a good case for the open method of treatment. The developed middle slip deformity is amenable in many cases to successful treatment by simple conservative methods, and very occasionally to surgical repair. These cases were admitted under the care of M r A. H. M. Littlewood and M r L. B. Scott, to whom I am grateful for permission to publish. The success obtained in Case 8 is attributable to M r A. H. M. Littlewood who operated on the index finger himself and encouraged me to treat the ring finger. I am indebted to him
THE MIDDLE
SLIP
OR BOUTONNIERE DEFORMITY IN
BURNED
HANDS
I29
f o r his help and encouragement in the preparation of this paper and also to M r R. P. Osborne f o r his constructive criticism of the manuscript. M y thanks are also due to M r R. R. Green for the photographs.
REFERENCES BRAITHWAITE, F., CHAr~NELL, G. D., MOORE, F. T., and WHILLIS, J. (1949). Brit. ft. plast. Surg., 2, 175. BRAITHWAITE,F., and WATSON, J. (1949). Brit. ft. Plast. Surg., 2, 21. BUI'ZlqELL,S. (1956). " Surgery of the Hand," 3rd ed. Philadelphia : Lippincott. CLARKSON,P., and EVANS, A. J. (1954). Med. Press, 232, 537. CLARKSON, P., and PELLY, A. (1952). " The General and Plastic Surgery of the Hand." Oxford : BlackweU Scientific Publications. Com3oI% K. C., and KAI'LAI~I,I. J. (1959). Brit. ft. plast. Surg., I2, 129. CRAVEN, R. E., and DIIRAI%R. J. (196o), Amer..7. Surg. xoo, 802. ENTIN, M. A. (196o). Surg. Clin. N. Amer., 40, 275. Em3ELYI, R. (1963). Plast. reconstr. Surg., 3 x, 14o. EVANS, A. J. (1953). Brit. J. plast. Surg., $, 263. FLATT, A. E. (1962). Ann. Roy. Coll. Surg. Engl., 3I, 279. GLANVlLLE, H. J. (1962). Lancet, i, 252. GRONLEY, J. K., YEAKEL,M. H., and GRANT, A. E. (1962). Arch. phys. Med., 43, 508. KYLE, M. J., and WALLACE,A. B. (195o). Brit. ft. plast. Surg., 3, 144. LANDSMEER,J. M. F. (1955). Acta anat. (Basel). Suppl. 24, 2, and vol. 25. -(1958). Acta. morph, neerl, scand., 2, 59. LEAMING, D. B., WALDER, D. N., and BRAITHWAITE,F. (196o). Brit. ft. Surg., 48, 247. Mclm~OE, R. H. (1944). Med. Press, 21i, 57. MONCRIEFE, J. A. (1958). Amer. ft. Surg., 96, 535. MUIR, I. F. K., and BARCLAY,T. L. (1962). " Burns and their Treatment." London : Lloyd Luke. NEMETHI, C. E. (1956). lndustr. Med. Surg., 25, 113. RANK, B. K., and WAKEFIELD, A. R. (196o). " Surgery of Repair as applied to Hand Injuries." Edinburgh : E. & S. Livingstone. ROBERTSON,D. C. (1958)..7. Bone fit. Surg., 4oA, 625. STACK, H. G. (1962). ft. Bone fit. Surg., 44 B, 899. TAYLOR, D. G. (1953). Brit. ft. plast. Surg., 5, 275. TRUETA, J. (1946). " The Principles and Practice of War Surgery," 3rd ed. London : Win. Heinemann. WALLACE,A. B. (1949). Brit. ft. plast. Surg., x, 232.