FRACTURES OF THE TLBIAL SHAFT. A Survey of 705 Cases

Transcription

1 FRACTURES OF THE TLBIAL SHAFT A Survey of 705 Cases E. A. NICOLL, MANSFIELD, ENGLAND This paper is based on a clinical research project undertaken in conjunction with a group of surgeons working in the hospitals of the South African mining industry. Agreement was reached in advance about the information to be recorded in each case, which was detailed and comprehensive in scope. Standardised methods of assessment and interpretation in clinical and radiological recording were also agreed. By conducting the survey on a prospective instead of a retrospective basis, complete and accurate records were assured and 705 fully documented cases were collected, 460 from South Africa and 245 from Britain. This information was then coded on Hollerith cards and analysed on data-processing equipment available at the Ernest Oppenheimer Hospital in Welkom and kindly placed at my disposal by the hospital authorities. The main objectives ofthe survey were: 1) To assess the results ofconservative treatment and to present these in a form likely to prove acceptable as a basis for valid comparison with other methods. It will be shown later that a straight comparison of results, even with large groups, can be extremely misleading in a complex issue such as this. 2) To investigate the factors leading to delayed and non-union. 3) To investigate the extent and causes of residual joint stiffness, contractures and residual deformity. The survey was confined to patients aged eighteen and over because these fractures in children and adolescents behave much more favourably, and to include them would flatter the results and thereby invalidate comparison with any series of adults. For the same reason crack fractures without displacement were also excluded. Of the 705 fractures, thirty-one were treated by primary plating or intramedullary nailing. These have not been included in the detailed statistical analysis because they did not afford a group large enough for valid statistical comparison. Twenty-seven of these were consecutive fractures from one hospital where primary internal fixation is routine policy. The remaining four were from my own series and were all closed fractures. In two of these the reason for operation was an irreducible middle fragment threatening to perforate the skin (Figs. 4 to 6); in the other two it was severe comminution with wide displacement of large fragments resulting in a gap likely to cause non-union. Six hundred and seventy-four fractures treated conservatively were therefore available for detailed analysis and with the four exceptions referred to above they were consecutive cases and therefore unselected. During the period of the survey there were in addition thirteen primary amputations for fractures of the tibia. These were cases in which mutilation was so severe that no attempt was made to salvage the leg. There were only three cases of secondary amputation among the 674 patients treated conservatively. Definition of delayed union and non-union-by non-union was meant a condition in which, in the opinion of the surgeon, the fragments would not have united with further conservative treatment. This is obviously a matter of individual judgement, but in certain cases-as when there was actual loss of bone with a substantial gap between the fragments, or sclerosis of the bone ends without periosteal callus-the decision can be made earlier and with more certainty. But the dividing line between delayed union and non-union must perforce remain imprecise in the majority of cases. One surgeon will decide after five months that the fracture is never going to unite and will proceed to graft it, whereas another, equally experienced, will insist VOL. 46 B, NO. 3, AUGUST

2 374 E. A. NICOLL that union is merely delayed and that another three months in plaster is all that is required. It was therefore decided to amalgamate delayed union and non-union for purposes of analysis. There were thirty-five cases of non-union, eighteen in the South African series (4 per cent) and seventeen in the British series (7 per cent), and these will be discussed later. RATE OF UNION The mean period of immobilisation in the 639 fractures that united after conservative treatment was sixteen weeks; the range was from nine to fifty-two weeks (Table I). It was therefore decided to adopt the following arbitrary standards of rate of union: Normal union to 20 weeks (16±4) Accelerated union.. Less than 12 weeks Delayed union..... More than 20 weeks In analysing the effect of various factors on the rate of union, normal and accelerated union were amalgamated into one group for comparison with delayed and non-union in the other. The influence of the following factors was investigated: age, site of fracture, shape of fracture, comminution, associated fracture of fibula, open or closed fracture, extent and severity of wound, infection, skin loss, initial displacement, traction and distraction. The TIME TAKEN FOR UNION IN 674 FRACTURES OF THE TIBIA Time taken Cumulative for union Number Percentage percentage (weeks) within period OverS Mean time taken for union: 159 weeks Non-union Total general plan followed was first to investigate factors inherent in the fracture itself. If any significant trends emerged the factors concerned were assessed in isolation to determine whether they were acting in their own right or by accidental association with other significant factors. Finally, factors concerned with treatment-for example, continuous traction-were examined having regard to the influence of significant factors inherent in the fracture. The most significant factors affecting union were found to be initial displacement, comminution, associated soft-tissue wounds, infection and distraction. Initial displacement-the degree of initial displacement in each fracture was classified as slight, moderate or severe. For purposes of analysis, moderate and severe displacements were amalgamated into one group for comparison with slight displacement in the other (Table II). It is clear from the above analysis that the rate of union is markedly affected by the initial degree of displacement. Delayed union and non-union was nearly three times as frequent when there was moderate or severe displacement as when the displaecment was slight. THE JOURNAL OF BONE AND JOINT SURGERY

3 FRACTURES OF THE TIBIAL SHAFT 375 Comminution-The degree of comminution was classified as nil, slight, moderate or severe. For purposes of analysis, nil and slight were combined in one group and moderate and severe in another (Table III). It is clear that comminution increases the risk of delayed union and non-union. Over the whole series the incidence was nearly twice as high in the presence of significant comminution. II RATE OF UNION IN RELATION TO DISPLACEMENT Accelerated and Delayed union Degree of initial normal union and non-union displacement Number Percentage Number Percentage Total Moderate to severe Slight Total RATE OF UNION IN RELATION TO COMMINUTION III Accelerated and Delayed union Degree of normal union and non-union comminution Number Percentage Number Percentage Total Moderate to severe Nil to slight Total RATE OF UNION IN RELATION TO NON-INFECTED WOUNDS IV Accelerated and Delayed union Type of wound normal union and non-union Total Number Percentage Number Percentage Moderate to severe Nil to slight Total infected wounds are excluded from this analysis Soft-tissue wounds-much depended on whether or not the wound was infected. There were twenty-two infected wounds in 144 open fractures and the incidence of delayed and non-union in these infected cases was 60 per cent. Infection is therefore a potent factor, and in order to assess the significance of the soft-tissue injury as such, infected wounds were excluded and the remaining cases amalgamated into two groups. Moderate and severe wounds constituted one group for comparison with closed fractures and slight wounds in the other. It appears that, infection apart, an associated wound of the overlying soft tissues increases the risk of delayed union or non-union (Table IV). A more detailed breakdown showed that this risk is in proportion to the severity of the wound. VOL. 46 B, NO. 3, AUGUST 1964

4 376 E. A. NICOLL It is clear from the foregoing analyses that a straight comparison between the results of conservative treatment and of internal fixation is valueless unless the type of case selected for operation is taken into consideration. Most surgeons would hesitate to use internal fixation in the presence of severe or heavily contaminated wounds, and in many cases of severe comminution internal fixation is impracticable anyway. It is therefore likely that cases selected for internal fixation will have an inherently better prognosis, and comparative statistics that fail to take this into account can be extremely misleading. In the present series, for example, it would have been possible to select for internal fixation a group of 254 closed fractures with minimal commin.u.tion and slight displacement in which the risk of delayed union was only 9 per cent (Table V). This would then have compared with a 31 per cent risk for the rest of the series treated conservatively and it might well have been claimed that the incidence of delayed union was greatlydiminishedbyinternalfixation. It is nothing of the kind; thedifference in the above example is inherent in the type of case selected for one or other treatment. Yet V INCIDENCE OF DELAYED UNION AND NON-UNION IN EACH OF EIGHT TYPES OF FRACTURE (EXCLUDING INFECTION) Accelerated and Delayed union Fracture type normal union and non-union Total Pe7entae Number Percentage Number Percentage 1(ND NC NW) (ND NC SW) (NDSCNW) (SD NC NW) (ND SC SW) (SD NC SW) (SD SC NW) (SD SC SW) Total N ==Nil or slight S = Moderate or severe D = Displacement C =Comminution W = Wound it is surprising how often such fallacies are overlooked when statistics are advanced in support of particular methods and ideas. These four factors-displacement, comminution, infection, associated soft-tissue woundall appear to have an effect on the rate of union, the most potent, but fortunately the rarest, being infection. To assess the effect of the other three factors, both in combination and isolation, the 652 non-infected cases were divided into eight types corresponding to the variation and combination of these three factors, and each type was analysed for the incidence of delayed union and non-union. EFFECT OF COMMINUTION, WOUND AND DISPLACEMENT In the above analysis some of the groups (for example groups 2, 5 and 6) are rather small for statistical accuracy, but the remaining larger groups show a steady rise in the rate of delayed union from 9 per cent to 39 per cent according to the personality of the fracture. By personality is meant the extent to which each fracture contains in its make-up certain factors prejudicial to union-in other words, its inherited criminal tendencies. THE JOURNAL OF BONE AND JOINT SURGERY

5 FRACTURES OF THE TIBIAL SHAFT 377 To confirm that each factor was acting in its own right and not by accidental association with other significant factors, a further analysis was carried out. In this the effect of each factor was assessed in isolation. The effect of significant factors in isolation is seen in Table VI, from which it appears that the order of potency is displacement, comminution and associated soft-tissue wound. VI EFFECT OF COMMINUTION, Woun AND DISPLACEMENT IN IsOLATION Fracture type Accelerated and normal urnon Percentage Delayed union and Number non-union of cases Percentage A. Comminution 1 (NC ND NW) (SCNDNW) A. Comminution, in the absence of other factors, increases the rate of delayed union and non-union from 9 to 15 per cent B. Wound (excluding infection) 1 (NW ND NC) (SW ND NC) B. Severe wounds, in the absence of other factors, increase the rate of delayed union and non-union from 9 to 12 per cent C. Displacement 1 (ND NW NC) (SD NW NC) C. Displacement, in the absence of other factors, increases the rate of delayed union and non-union from 9 to 27 per cent N = Nil or slight S = Moderate or severe D = Displacement C=Comminution W=Wound VII RATE OF UNION IN RELATION TO INFECTION AND LOSS OF BONE Accelerated and Delayed union normal union and non-union Total Number Percentage Number Percentage Infected fracture Bone loss (no infection) To these must be added two other highly significant factors-infection (60 per cent delayed union and non-union in twenty-two cases) and actual loss of bone (65 per cent in twenty cases) (Table VII). Loss of bone between the main fragments is always associated with severe comminution and was included with these cases in the present series. VOL. 46 B, NO. 3, AUGUST 1964

6 378 E. A. NICOLL These five factors-comminution, wound, displacement, infection and loss of boneconstitute the background against which all other factors must be examined, and any comparison of methods which fails to take them into account can be entirely misleading. Similar conclusions have been reported by Ellis (1958) and De Buren (1962). OTHER FACTORS Significance of site of fracture-having established that there are different fracture types with wide differences in rates of union we next examined the significance of the fracture site. This has long been assumed to influence the rate ofunion and it is commonly accepted that fractures at the junction of the middle and lowest thirds are at greater risk. In the present series this VIII EFFECT OF FRACTURE SITE ON UNION Site of fracture Percentage Fracture Number of incidence of type fractures delayed union Uppermost third Middle third Lowest third nndnon-union Number of Number at Number of Number at Number of Number at - fractures risk fractures risk fractures risk l l l Totals l #{149}I) rdicdndumberofcases #{176} 13 (22 per cent) 75 (21 per cent) 49 (21 per cent) Actual number of cases. 13 (22 per cent) 87 (24 per cent) 39 (17 per cent) was not borne out. A straight analysis shows an apparently higher incidence in the middle third (24 per cent) but this fails to take into account the possibility of unequal distribution of fracture types or infected cases. A more detailed analysis was therefore carried out in which the fracture site was examined in relation to the eight fracture types. The number of cases of delayed union which could be expected to occur at each site according to the distribution of fracture types at that site was calculated statistically. This was then compared with the actual incidence. If the difference between the predicted and the actual results is statistically significant then the fracture site must itself be influencing union. The same method was used in investigating the possible significance of age, shape of fracture, traction and other factors. The outcome in the case of fracture site is shown in Table VIII. There is a slightly higher risk of delayed union in the middle third and a slightly lower risk in the lowest third. Traction and disfraction-the effect of continuous traction was investigated by the same method. THE JOURNAL OF BONE AND JOINT SURGERY

7 FRACTURES OF THE TIBIAL SHAFT 379 It has been widely accepted that continuous traction prejudices union and that distraction will almost certainly cause non-union. Watson-Jones and Coltart (1943) found that in a series of 319 closed tibia! fractures immobilisation with continuous traction but without distraction produced union within sixteen weeks in 43 per cent of cases, whereas continuous immobilisation without traction produced union within the same period in 75 per cent of cases. They argued from this that continuous traction delays union and that if the fracture is of unstable type and EFFECT OF CONTINUOUS TRACTION ON DELAYED UNION AND NON-UNION IX Fracture Percentage No traction Number of incidence of - - Traction type fractures delayed union and non-union Number of Number at Number of Number at fractures risk fractures risk l l l Totals Predicted.... III 29 Actual X INCIDENCE OF DELAYED UNION IN FRACTURES TREATED WITH AND WITHOUT TRACTION Number of fractures Non-union at sixteen weeks Wat5OnJon( Number Percentage and Coltart (percentage) Traction No traction redisplacement is likely to occur it should be stabilised by internal fixation. The influence of comminution and displacement was not taken into account. In the present survey ninety-three fractures were treated by continuous traction and these were compared with 559 fractures treated without traction. The predictable incidence of delayed union was calculated as before, having regard to the distribution of the eight fracture types, and this was compared with the actual incidence. It was found that continuous traction in the absence of distraction had no significant effect on the rate of union (Table IX). VOL. 46 B, NO. 3, AUGUST 1964

8 380 E. A. NICOLL There was, however, a much higher actual incidence of delayed union among the cases treated by continuous traction. On the dividing line of twenty weeks adopted in the present series this was 31 per cent compared with 19 per cent in fractures treated without traction. If the dividing line is drawn at sixteen weeks, as in the series of Watson-Jones and Coltart, the figures are 52 per cent and 35 per cent respectively, which is approximately the same order of difference as in their cases (Table X). The analysis in Table IX shows, however, that this difference is not caused by the traction but by the greater incidence of higher risk fracture types among the cases so treated. Distraction-The number of cases in the present series was too small to be statistically significant. There were only three cases, two of which resulted in non-union and one in delayed union. In the South African series traction was used only to aid reduction and not to maintain it after it had been achieved. In 432 South African cases significant shortening (more than 2 centimetres) occurred in nine cases (2 per cent) compared with eight cases (3 per cent) in the British series, so this difference in policy did not affect shortening. EFFECT OF AGE ON DELAYED UNION AND NON-UNION XI Age of patient (years) Type of Total fracture cases Percentage incidence of delayed union and non-union Number of Number at -- patients risk and over Number of Number at Number of Number at patients risk - patients - risk O l l i l #{149} Total 652 P573 li Predicted Actual The rate of union is not affected by age in the range 18 to 60. Over the age of 60 there appears to be some retardation of the reparative process. Age-In the South African series, derived from Bantu workers in the gold mines, the age was not always known precisely, but all the patients were between eighteen and forty years old. In the British series there were only twenty-seven patients over the age of sixty, which is rather small for valid statistical comparison. Within the remaining age groups there was no significant difference between the predicted and actual results, so that age within the range of eighteen to sixty does not affect the rate of union (Table XI). The rate of union is, of course, markedly accelerated in childhood and adolescence, but there is no evidence that it changes once growth has ceased. It is possible that the reparative process remains as active in old age as in adult life, though the results in the present series appear to indicate a falling off over the THE JOURNAL OF BONE AND JOINT SURGERY

9 FRACTURES OF THE TIBIAL SHAFT 381 age of sixty. This is based on such a small number of cases, however, that it needs confirmation in a larger series. Fractured fibula-it is sometimes assumed that an intact fibula is prejudicial to union because it holds the fragments apart when absorption occurs at the fracture line. In the present series there was nothing to substantiate this belief; in fact the reverse was true. The incidence of delayed union when the fibula was intact, without considering other factors, was 9 per cent (the same as for fractures of Type 1). When the fibula was fractured the incidence was the same as in Type 4 fractures (29 per cent). EFFECT OF FRACTURED FIBULA ON DELAYED UNION AND NON-UNION XII Accelerated and Delayed union State of normal union and non-union fibula - - Number Percentage Number Percentage Intact Fractured Totals It appears likely that an intact fibula is significant only in so far as it affects the degree of initial displacement and the stability of the fracture. Other factors-the shape of the fracture (transverse or oblique) was not significant. Skin loss was significant only in so far as it was related to infection and the severity of the wound. Chronic anaemia did not occur so its effect could not be ascertained. Blood transfusion was carried out in only eight cases and there was only one death-caused by pulmonary embolism. Routine haemoglobin estimations on closed fractures were carried out at forty-eight hours early in the series, but these were so consistently normal that the practice was discontinued. There was no clinical evidence of occult blood loss-so often advanced as a reason for routine blood replacement. There were twenty-eight patients with a positive Wassermann reaction but their fractures did not appear to behave differently in any way. There was no apparent ethnic difference. RESIDUAL JOINT STIFFNESS Because of the difficulty of long term follow-up in a shifting Bantu population, this part of the survey was confined to the British series. The range of movement in each joint was recorded on the patient s discharge, the corresponding joint on the normal side being used as a basis of comparison. It was known, however, that this did not necessarily represent the true end result. Many patients seen some time later for insurance purposes showed joint ranges significantly greater than those recorded at the completion of treatment, and it is clear that improvement continues for a long time with simple active use ofthejoint. It was necessary first to decide what constitutes functionally significant loss of movement in different joints, and certain conclusions were reached after examining a large number of patients and assessing function in relation to joint movement. Functionally insignificant loss implied a degree of limitation detectable by the examiner, but not as a rule by the patient, and not affecting function. The following criteria of functionally significant loss were adopted: Knee-Any loss of extension; loss of more than 10 degrees of flexion. Ankle-More than 25 per cent loss of extension or flexion. Tarsus-More than 25 per cent loss of inversion or eversion. The advocates of routine internal fixation frequently seek to justify their approach on the grounds that, while not increasing the risk of other complications, it eliminates residual joint stiffness, which, they imply, is a frequent and serious complication of conservative treatment. It is therefore of some importance to ascertain the extent to which such stiffness VOL. 46 B, NO. 3, AUGUST 1964

10 382 E. A. NICOLL occurs and how far it is related to the immobilisation itself and how far to initial irreparable damage inflicted on the soft tissues concerned injoint movement. In certain cases the soft-tissue damage is such that residual stiffness must be inevitable with any method of treatment. Furthermore, if immobilisation is to be blamed, then, to be logical, internal fixation must be so rigid that plaster can be dispensed with and joint movement started immediately. This is in fact the attitude adopted by Muller (1963) and his associates in Switzerland, to whom the main purpose of internal fixation is to permit immediate free use of the joints. In the 241 patients followed up to resumption of working capacity there were sixty-two (25 per cent) with significant residual stiffness in one or more joints. Thirty-eight of these had only one joint affected, twenty-three had two joints and only one patient had all three joints affected. The degree of stiffness, which is very important in the assessment of function, was also analysed. Severe stiffness in the ankle (over 50 per cent loss of extension or flexion) occurred in five cases ; in the foot (more than 50 per cent loss of inversion or eversion) in eleven cases ; and in both combined in two cases. In the knee there were only three cases of severe limitation, one with 15 degrees loss of extension and two with more than 30 degrees loss of flexion. In this series of 24! patients, therefore, there were twenty-one (8 per cent) XIII INCIDENCE OF SEVERE STIFFNESS (OVER 50 PER CENT LIMITATION) IN ANKLE AND TARSUS IN 241 PATIENTS (BRITISH SERIES) Movements involved Ankle only Tarsus only Both joints Extension only... 2 Flexion only... 2 Both combined... I Inversion only... 6 Eversion only... 1 Both combined... 4 Extension plus inversion. I Flexion plus eversion.. Total patients with really disabling stiffness. In nineteen of these only one joint was affected, and in fourteen only one range of that joint. Of the remaining seven, two patients had severe stiffness both in the ankle and tarsus and five had both ranges of one joint affected (Table XIII). The above figures give some indication of the incidence of residual joint stiffness in fractures treated conservatively. The next point is to ascertain to what extent this is related to immobilisation and therefore theoretically avoidable by internal fixation with immediate movement. The analyses in Tables XIV and XV relate significant residual joint stiffness to soft-tissue damage on the one hand and to prolonged immobilisation on the other. In this series no fractures were treated without immobilisation of the joints, so the comparison was necessarily between the shorter immobilisation associated with normal or accelerated union (average thirteen weeks) and the more prolonged immobilisation of delayed and non-union (average thirty-one weeks). It is clear from the analysis in Tables XIV and XV that:-!) The incidence of significant joint stiffness is nearly three times higher in the presence of moderate or severe wounds and this is so whether union is normal or delayed. When there is no wound, however, the incidence of joint stiffness increases only slightly (from 20 to 25 per cent) as a result of prolonged immobilisation caused by delayed union. 2) The highest incidence of residual stiffness (70 per cent) is produced by the prolonged immobilisationofdamaged soft tissues-that is, a combination of delayed union and severe wound. It has not been established, however, that such cases THE JOURNAL OF BONE AND JOINT SURGERY

11 FRACTURES OF THE TIBIAL SHAFT 383 would regain significantly better movement if treated by internal fixation and immediate mobilisation, even if this were possible or desirable. Contractures-Contractures in the ankle or foot were extremely rare-only five cases in the South African series and none in the British series. These are avoidable complications. XIV SIGNIFICANCE OF SOFT-TISSUE WOUNDS AND PERIOD OF IMMOBILIsATI0N IN RELATION TO RESIDUAL JOINT STIFFNESS (British series only) Wound nil or slight (Fracture types 1, 3, 4 and 7) Normal union Delayed union Numberwith Fracture type Number Number with Number Number with All patients residual of residual of residual joint stiffness patients joint stiffness patients joint stiffness Il Totals (2Opercent) 43 11(25 percent) (21 percent) Wound moderate or severe (Fracture types 2, 5, 6 and 8) Totals (SOpercent) 13 9(7Opercent) 27 16(6opercent) Totals (allpatients) (23 per cent) 56 20(36 per cent) (25 per cent) PERCENTAGE OF PATIENTS WITH SIGNIFICANT RESIDUAL XV JOINT STIFFNESS Percentage with residual stiffness Wound nil or Wound moderate slight or severe Normal union Delayed union All patients caused occasionally by major vessel damage but mostly by tight plasters or tissue tension under rigid fascial structures. Like Volkmann s contracture in the forearm, they result more from treatment than from the injury itself. VOL. 46 B, NO. 3, AUGUST 1964

12 384 E. A. N1COLL RESIDUAL DEFORMITY The following criteria were adopted as significant ; they were based on the assessment of function in cases in which no other factor was involved. Valgus or varus angulation. Anterior or posterior bowing - 10 degrees or more Rotational deformity.. Shortening... Over 2 centimetres Of 671 patients fifty-eight (86 per cent) had significant residual deformity, forty in a single plane and eighteen in two planes. In eighty-eight further cases deformity of less than 10 degrees occurred and appeared to cause no loss of function. The distribution was different in the two series, being four times higher in the South African series, and it is thought that this may be caused by the British practice of controlling unstable fractures after reduction by a Steinmann pin through the upper fragment incorporated in the plaster. In South Africa skeletal traction was used only to obtain reduction and not to XVI RESIDUAL DEFORMITY IN 671 LEGS Functionally Moderate Severe insignificant Total!,l \ 1 lod ees) egrees, egrees, Anterior or posterior angulation Valgus or varus Rotational deformity Multiple deformity (two planes) 13 I I 7 31 Totals British series: Significant deformity occurred in 7 of 241 legs (3 per cent) Combined series: Significant deformity occurred in 58 of 671 legs (86 per cent) Significant shortening (over 2 centimetres)-i7 legs (25 per cent) maintain it. Severe residual deformity (over 20 degrees) occurred in only twelve cases (Table XVI). It is clear from these figures that angular and rotational deformity can always be satisfactorily controlled by conservative treatment and that the objective of good alignment without significant shortening can be achieved in practically all cases (97 per cent in the British series). DISCUSSION It is now possible to examine the claims of internal fixation as a treatment of choice. This is widely practised in many countries and has gained fresh impetus in Europe from the work of Muller and his associates in Switzerland. There can be only one reason for submitting a patient to the additional hazard of surgery, and that is to ensure a good functional result unlikely to be achieved by conservative treatment. The argument so often advanced in the case of the fractured femur-that the patient can be rendered mobile much earlier-does not apply to the fractured tibia. Practically all fractures can be stabilised and the patient can become ambulant in plaster within a few days. Internal fixation can therefore only be justified on one of the following grounds: 1) that it reduces the incidence of functionally significant deformity and joint stiffness; 2) that it significantly lowers the risk of delayed and non-union; THE JOURNAL OF BONE AND JOINT SURGERY

13 FRACTURES OF THE TIBIAL SHAFT 385 and 3) that the advantages so claimed are great enough to outweigh the additional hazards of surgery, which in a subcutaneous bone like the tibia can be disastrous. Residual stiffness and deformity-it has already been shown that residual stiffness and residual deformity are not serious hazards of conservative treatment and that residual stiffness is more closely related to soft-tissue damage than to immobilisation. It results from fibrosis in muscles, fascial planes and ligaments irretrievably damaged at the time of the injury and there is no proof that internal fixation, even with immediate movement, will avert stiffness from this cause though it may lessen it. However, this is a matter on which judgement must be reserved until comparative statistics are available. With regard to shortening and residual deformity. it has been established that these are avoidable if proper safeguards are adopted against recurrent displacement in unstable fractures. This can be achieved quite simply by transfixing the upper fragment with a pin incorporated in the plaster. It is not necessary to transfix both FIG. I FIG. 2 FIG. 3 An unstable reduction can be stabilised by transfixion of the upper fragment and incorporation of the pin in the plaster (Figs. 1 and 2). This also serves to prevent the constant movement of the upper fragment that inevitably results from quadriceps drill in plaster. Union occurred in six months (Fig. 3). fragments if the plaster is well moulded round the ankle (Figs. 1 to 3). Irreducible displacement does occasionally occur, but it is very rare in the tibia. In the case shown in Figures 4 to 6 the large separate middle fragment was uncontrollable and threatening to perforate the skin. Open reduction was therefore essential and this was so unstable that internal fixation was carried out. Union was delayed for eight months but eventually occurred, with an excellent functional result and full joint movement in spite of the fact that fixation in plaster had also been used. Non-union-No comparative figures are available which take into account the different fracture types, but it is difficult to imagine that the overall rate of 5 per cent could be significantly reduced by routine internal fixation. Moreover, the fractures with the greatest risk of nonunion-those with large wounds, skin damage, severe comminution and a danger of infectionare precisely those in which internal fixation is impracticable even in the hands of the most venturesome surgeon. Furthermore, there is considerable evidence that internal fixation VOL. 46 B, NO. 3, AUGUST 1964

14 386 E. A. NICOLL actually delays union unless it is absolutely rigid, and this is never the case with intramedullary nailing or with plating carried out in the conventional manner. Rigid fixation is an invaluable device in the treatment of non-union, but it is not justified as a prophylactic measure in the treatment of fresh fractures with a 95 per cent expectation of union. It is not the purpose of this paper to deal with the treatment of non-union, but a few points emerged from a study of the eighteen cases in the British series. In one of these there was fibrous union so firm as to be clinically indistinguishable from bony union. No treatment FIG. 4 FIG. 5 FIG. 6 Irreducible displacement-one of the rare indications for open reduction and internal fixation (Figs. 4 and 5). The sharp edge of the displaced middle fragment was threatening to perforate the skin. Union occurred in eight months (Fig. 6). was undertaken and the patient is doing heavy work without pain or other disability. The remaining bones were all successfully grafted but three failed at the first attempt. These failures were all related to inadequate fixation. There is no doubt that in the surgery of non-union the most important single principle of technique is rigid fixation, and it is now established that this can produce bony union even in the absence of grafting. This is in accord with the author s experience of a large series of grafting operations over the years. The successful incorporation of a graft depends ultimately on its impregnation with primitive mesenchyme cells, and their subsequent conversion into osteoblasts, and it is not surprising THE JOURNAL OF BONE AND JOINT SURGERY

15 FRACTURES OF THE TIBIAL SHAFT 387 that rigidity should be a vital factor in the environmental conditions conducive to this differentiation. Rigidity is, after all, the one physical property peculiar to bone as a tissue. SUMMARY 1. A series of 705 fractures of the tibia is reviewed, 674 of which were treated conservatively. 2. The factors most conducive to delayed or non-union are initial displacement, comminution, associated soft-tissue wound and infection. The extent to which these are combined in any fracture determines its personality and its inherent propensity for union. 3. Eight fracture types are differentiated based on the above personality rating. The incidence of delayed union or non-union varies from 9 per cent in the most favourable type to 39 per cent in the least favourable. Infection raises the incidence to 60 per cent. Comparative statistics which fail to recognise these differences can be entirely misleading. 4. Continuous traction does not retard union. 5. The results of conservative treatment are analysed with regard to union, deformity, stiff joints and contractures and the conclusion is reached that no case has yet been made out for internal fixation as the method of choice in the treatment of this fracture. This work was carried out with the help of a research grant from the Chamber of Mines of South Africa and with the participation of a group of surgeons working in the hospitals administered by the mining industry. I am particularly indebted to Dr Kurt Sartorius, Chief Medical Officer of the Union Corporation, who acted as chairman of the research team in South Africa and was responsible for the collection and coding of the data over a period of three years. I am also greatly indebted to Mr Dennis Evans whose help in the final analysis of the data and the compilation of the statistical tables was invaluable. REFERENCES Dr BUREN, N. (1962): Causes and Treatment of Non-Union in Fractures of the Radius and Ulna. Journal of Bone and Joint Surgery, 44-B, 614. ELLIS, H. (1958): Disabilities after Tibial Shaft Fractures. Journal of Bone and Joint Surgery, 40-B, 190. MULLER, M. E. (1963): Internal Fixation for Fresh Fractures and for Non-union. Proceedings of the Royal Society of Medicine, 56, 455. WATSON-JONES, R., and COLTART, W. D. (1943): Slow Union of Fractures with a Study of 804 Fractures of the Shafts of the Tibia and Femur. British Journal of Surgery, 30, 260. VOL. 46 B, NO. 3, AUGUST 1964 B