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Problems and pitfalls of compression fixation of long bone fractures: a review of results and complications
Injury, 10, 99-107 Printed in Great Britain
99.
Problems and pitfalls of compression fixation of long bone fractures: a review of results and complications W. D. Fisher and D. L. Hamblen University Department of Orthopaedics, Western Infirmary, Glasgow Summary
The complications encountered in the compression fixation of 70 cortical long bone fractures are reviewed. The results represent the initial experience with the AO fixation equipment following its introduction to a centre with staff relatively untrained in the technique. Infection was the most serious complication, with a deep sepsis rate of 10.5 per cent, but fixation failure, delayed union and refracture also occurred. The various problems are discussed in detail and suggestions are made as to how they can be avoided.
INTRODUCTION CONTROVERSYstill exists over the place of internal fixation in the routine management of long bone fractures. To justify acceptance, the results of its use must compare favourably with the good results reported from the conservative management of both lower and upper limb fractures (Nicoll, 1964; Charnley, 1972). It also increases the risk of infection, which is still a common complication of internal fixation, particularly in the presence of an open fracture (Burwell, 1971; Smith, 1974). However, the techniques of internal fixation have been improved with the development of more rigid implants (Hicks, 1971) and the concept of compression fixation introduced by the Swiss AO Group (MiJller, 1963; Allg6wer et al., 1969; Mtiller et al., 1970). These developments have been based on the animal experimental work on fracture healing by Perren et al. (1969) and there has been a renewal of interest in the technique. The aim of AO is to achieve an early return to full function of the injured limb by accurate anatomical reduction and rigid internal fixation to allow early mobilization. The instru-
mentation and implants for this method are available in an increasing number of orthopaedic units, but the techniques are often used by orthopaedic surgeons and trainees with little practical experience in their application. It was felt that an early critical review of the results following the introduction of the technique to one centre would be of value in assessing its efficacy for general use. To simplify the study, it was confined to cortical fractures in the shafts of long bones with the exclusion of metaphyseal and epiphyseal injuries.
PATI E NTS Between October 1973 and March 1976 70 patients with long bone fractures were treated by compression fixation in the Accident Unit of the Western Infirmary, Glasgow. The distribution of fractures was as follows: tibia, 40 patients; femur, 6 patients; forearm, 15 patients with involvement of both. bones, 7 with isolated fractures of the radius and 2 of the ulna (total 24). While primary internal fixation was the treatment of choice in almost all patients presenting with displaced fractures of the forearm bones, it was only used in one-third of all fresh fractures of the tibia and was rarely indicated for fractures of the femoral shaft. When internal fixation was required in the femur, medullary nailing was preferred, except for delayed union of fractures in the distal third of the femoral shaft. Only onethird of the patients had sustained their injuries in high velocity road traffic accidents, the remaining fractures being sustained at work, during sport or in domestic accidents. Sixteen of
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Injury : the British Journal of Accident Surgery Vol. 10/No. 2
the tibial fractures were open (40 per cent), but no open fractures occurred in the other bones. The average age of the patients was 40.5 years (range 12-90 years). There were 2 deaths in the series. One was a 90-year-old woman with a spiral fracture of the femur who died 6 h after plating of the fracture, and the second patient was a 56-year-old woman with a tibial fracture who died at 16 weeks of unrelated causes. Two other patients were excluded from the series. One man with a tibial fracture was lost to follow-up after 6 weeks and one man required early amputation for ischaemia of the foot after internal fixation of a tibial fracture. The remaining 66 patients were followed until radiological union had occurred or clinical function was satisfactory. The mean length of follow-up was 1 year (range 3 months to 3 years).
Technique of fixation In 55 patients fixation of the fracture was achieved by means of a plate, supplemented in some cases by a compression screw. Tension was applied to the plate either by means of an external tensioning device or by the insertion of off-set screws in a dynamic compression plate (DCP) (AIlg6wer et al., 1969). The other 15 patients with more oblique or spiral fractures of the tibial shaft were treated by compression screws alone. It was not standard practice to dispense entirely with external splintage after fixation of the fracture. All tibial fractures were protected after wound healing by a patellar weight-bearing plaster cast for 6-12 weeks (Sarmiento, 1967), allowing knee mobility. After fixation of most forearm fractures the arms were allowed to move freely, although in 7 patients (29 per cent) a long arm cast was used for 2-8 weeks after operation. Fractures of the shaft of the femur were treated in splintage until muscular control of the limb was restored. Postoperative suction wound drainage, though recommended by AO, was not used routinely. Antibiotic cover during surgery and for the first postoperative week was used in 50 per cent of cases, including all open fractures. It was not the policy to remove implants routinely, except in the presence of a complication such as loosening, infection, previous infection or when subcutaneous placement of the implant was causing irritation. R ES U L T S
The radiological and clinical results were reviewed in 66 of the 70 patients. It was not possible to assess the state of union on clinical grounds in the presence of rigid internal fixation. The radio-
logical assessment of union was often difficult, because the presence of a large implant made it difficult to see the fracture line clearly and union frequently occurred without visible callus. This latter phenomenon is said to be the expected result of primary bone healing in a fracture correctly treated by compression fixation. However, in this series, 50 per cent of cases showed radiological union with visible periosteal callus. In many cases this was observed when the functional result was otherwise excellent and the compression fixation apparently adequate. In 53 patients (80 per cent) union occurred without further intervention. In all but 3 of the 34 patients with tibial fractures full ambulation without assistance was possible at an average of 16 weeks. One further patient regained normal movement but remained chairbound from other causes and two patients required assistance in walking because of other injuries. The 15 patients who had sustained forearm fractures regained functional use of the arm in an average of 11 weeks. All 4 uncomplicated femoral fractures regained normal function at an average of 18 weeks. Only 32 of the patients (60 per cent) had a full range of movement in the adjacent joints at the time of final review and 4 patients (8 per cent) had limitation of joint movement of more than 60 per cent. COMPLICATIONS
Complications preventing successful primary healing of the fracture after fixation occurred in 13 patients (20 per cent) and are listed in Table I.
Infection This was the commonest complication encountered and in the 67 patients reviewed before 3 months there were 7 deep infections, a rate of 10"5 per cent. Only 1 occurred in a forearm fracture, the other 6 were in the tibia, giving a deep infection rate in this group of 15 per cent. Five of the infected fractures were closed and only 2 were open. Deep infection usually occurred within a few days of operation, presenting with pain, erythema, discharge of pus and later radiological evidence of periosteal reaction and resorption around the implant. In 6 other patients (9 per cent) there was evidence of delayed wound healing or superficial infection, but these all healed with antibiotic therapy without further complications or radiological changes. However, if these are added to the deep established infections, the overall infection rate becomes 19-5 per cent. It was surprising that infection was not more frequent in open fractures, where the rate
Fisher and Hamblen : Compression Fixation of Long Bones
101
Table I. C o m p l i c a t i o n s o f internal f i x a t i o n Complication Infection Superficial Deep Failure of f i x a t i o n Screws
Plate Implant failure Refracture Delayed or n o n - u n i o n Reoperation
Tibia
Radius and ulna
Femur
Total
%
4 6
2 1
---
6 7
9 10-5
3
--
--
3
1
1
1
3
-1 6 7
1 1 3 3
--1 1
1 2 10 11
Fig. I. Fig. 2. Fig. 1. Comminuted compound fracture of distal tibia and fibula. Fig. 2. Radiograph 2 weeks after internal fixation and bone grafting of fractures. Fig. 3. Radiograph after removal of plate and screws for persistent osteitis of tibia. was 25 per cent (2 superficial and 2 deep in 16 patients). Deep infections were treated on diagnosis with antibiotics and 3 healed without further symptoms, though the implant was removed later in 2 of these patients. In another 2 patients refracture occurred following the removal of the implants at 32 weeks after apparently successful antibiotic treatment. In the remaining 2 patients with infected tibial fractures the plate was removed when it became loose and bone grafting was carried out. One of these patients had sustained an almost complete degloving injury of the skin of the leg, necessitating repeated skin grafting before the tibial fracture finally united after 18 months. The other patient was an elderly man with a
j
10"5 3 15 15-7
Fig. 3.
severely comminuted fracture of the distal tibia sustained when he was run over in a traffic accident (Fig. 1). Stability was achieved by plating both the tibia and fibula with the addition of a large iliac crest bone graft to the tibial defect (Fig. 2). A persistent pseudomonas osteitis developed, requiring removal of the tibial plate and further grafting (Fig. 3). Despite this, further resorption and collapse occurred (Fig. 4) leading to below-knee amputation after 22 months. Fixation failure There were 6 patients in whom failure of fixation occurred without evidence of implant breakage or deep infection. Loss of fixation occurred in 3 of the 15 tibial fractures treated by compression lag
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=
bone grafting, while in the third, bone grafting was augmented by compression plating of the fracture with a satisfactory result. In 3 patients loosening of a plate occurred following an apparently satisfactory compression fixation. A review of the initial radiographs in 2 of these patients suggested that 1 screw had been malpositioned and had probably entered the fracture line, thereby weakening the original fixation. The third patient was an elderly woman who sustained a spiral fracture of the femoral shaft below a malaligned hip prosthesis (Fig. 7). This required treatment by a lag screw and fixation with a compression plate (Fig. 8) to permit early mobilization, but loosening occurred after 10 weeks (Fig. 9). The fixation of the plate to the proximal fragment can be seen to be inadequate as it is so near to the hip implant. An additional factor may have been the osteoporosis associated with chronic joint disease. Union occurred in splintage after removal of the plate and after bone grafting.
Fig. 4. Established non-union and chronic osteitis of tibia and fibula.
Fig. 5. Fig. 6. Fig. 5. Spiral fracture of tibia treated with interfragmentary compression screws. Fig. 6. Radiograph showing loosening of screws and refracture at 6 weeks following minor trauma. screws alone (Fig. 5), with loosening of the screws and refracture following mobilization of the limb out of plaster (Fig. 6). In 2 of these patients union was achieved by removal of the screws and
Implant failure In one obese but energetic patient, bending of an implant occurred with failure of fixation. His fractures of both forearm bones were fixed "by
Fisher and Hamblen : Compression Fixation of Long Bones
103
function including full rotation. Delayed union or non-union Delayed union or non-union occurred in 10 patients (t5 per cent). The majority of these instances were attributable to the other complications already described. Two were associated with deep infections and 7 with failure of the implant or its fixation. Further bone grafting was required in 9 patients, while prolonged immobilization resulted in union of the remaining forearm fracture after 36 weeks.
Refracture
Fig. 7. Radiograph of spiral fracture of femur below a hip prosthesis.
Refracture occurred in 2 patients following early removal of the implants. One closed comminuted fracture of the tibia (Fig. 13) became infected following fixation with a dynamic compression plate. The plate was removed at 32 weeks because of continued discomfort, though radiographs at this stage (Fig. 14) appeared to show sound bony
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, ~ J '2_
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.
Fig. 8.
Fig. 9. Fig. 8. Femoral fracture fixed with an interfragmentary screw and compression plate. Fig. 9. Radiograph showing plate loosening and refracture at I0 weeks. means of two semi-tubular plates (Fig. 10) without the protection of external splintage. Following a period of over-use during motorcycle racing, bending of the radial plate occurred (Fig. 11) and resulted in delayed union of the fracture. Removal of the plate with bone grafting and recompression o f the radius using a heavier plate was combined with excision of the lower end of the ulna (Fig. 12). This resulted in satisfactory union of the radius and recovery of normal forearm
union. Four weeks later, following a minor stumble, refracture occurred through the site of original injury (Fig. 15). The second patient had the plating of fractures of both forearm bones complicated by deep infection (Fig. 16), requiring removal of the implants at 32 weeks (Fig. 17). Two weeks later the bones refractured through one of the screw holes in the radius and at the site of the original fracture in the ulna (Fig. 18). Union occurred following a further period of
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Injury: the British Journal of Accident Surgery Vol. 10/No. 2
Fig. 10. Fig. 11. Fig. 12. Fig. 10. Radiograph of forearm fractures fixed with. two semi-tubular plates. Fig. 11. Bending of radial plate with loosening of screws and delayed union. Fig. 12. Radiograph following bone grafting, replating of radius and excision of distal ulna.
:v "r:: °,
Fig. 13. Fig. 14. Fig. 15. Fig. 13. Radiograph following fixation of a transverse fracture of the tibia with a DCP plate. Fig. 14. Apparent radiological union of tibia at 32 weeks. Fig. 15. Radiograph showing refracture of tibia following removal of plate. immobilization but another refracture of the radius occurred through a screw hole 5 months after the removal of plaster.
DISCUSSION When the AO compression fixation equipment was introduced to our centre it was to be expected that such a novel and beautifully instrumented system would prove irresistible to orthopaedic surgeons at every level of training. Any attempt to
limit its use to selected personnel was felt to be impracticable, despite the fact that only one consultant had attended the Davos course. Some of the other members of staff had received instruction at shorter courses held in the United Kingdom. The expected result was that 18 different surgeons performed the first 70 long bone fixations. However, the 6 members of the consultant staff carried out 40 (57 per cent) of the operations and supervised most of the others.
Fisher and Hamblen : Compression Fixation of Long Bones
105
Fig. 16. Fig. 17. Fig. 18. Fig. 16. Radiograph showing plated fractures of both forearm bones complicated by infection. Fig. 17. Appearances of radius and ulna following removal of plate. Fig. 18. Radiograph showing refracture through the ulna and radius screw hole. The inevitable lack of familiarity with the techniques and instruments must have contributed to the high complication rate, which was unrelated to the seniority of the operating surgeon. The reoperation rate of 15.7 per cent is not much higher than the 10"5 per cent rate in a large series of tibial fixations carried out by more experienced surgeons(Battenet al., 1978) (see pp. 108-114) and less than the 19 per cent in another series (Olerud and Karlstr6m, 1972). The severity of the initial injury varied widely and fixation was delayed in a significant proportion of fractures following an initial trial of conservative treatment. Twelve (50 per cent) of the forearm fractures and 10 (25 per cent) of the tibial fractures were fixed following failure of closed reduction and plaster immobilization. The most serious complication was infection, and this reached an unacceptably high level of 10-5 per cent for deep sepsis, with a 19.5 per cent overall infection rate. As all the operations were carried out in new operating theatres, under apparently ideal conditions, this rate must reflect factors other than the operating environment. It could be related to the prolonged operating time and excessive tissue damage associated with the technical inexperience of the operating surgeon, assistants and theatre nurses. Improved training and increasing experience should decrease the infection rate, but what other measures can be utilized to reduce it ? Routine suction drainage of wounds is recommended by AO but was used infrequently in this series. Drainage was used in only 4 forearm fractures and 4 tibial fractures,
though 4 of the 6 femoral fractures were drained. Although 2 of the deep tibial infections occurred in drained cases, the elimination of post-fixation haematoma should form a logical routine part of the management. The other possible method is the use of prophylactic antibiotics as a means of reducing the postoperative infection rate. In this series they were used routinely for all open fractures of the tibia, but despite this the infection rate in this group reached 25 per cent. In closed fractures of the tibia they were used in 10 of the patients (40 per cent), but again this group included 2 deep and 2 superficial infections. Decreased infection rates have been reported with prophylactic antibiotics and it could be argued that they should be used by the less experienced surgeon until his technique has been perfected and the operating time thereby reduced. Infection must be regarded as a very serious complication of the internal fixation of fractures. Even when it responds to antibiotic therapy, it may still result in loosening of the implant, necessitating its premature removal, or may interfere with the process of primary bone healing with an increased risk of refracture. Failure of fixation, which occurred in 7 patients (10.6 per cent), must reflect poor technique or the incorrect choice of implant. When the patients treated by compression screws alone were considered as a separate group, the failure rate rose to 20 per cent (3 out of 15). Even when this technique is used for the correct type of spiral fracture, when the fracture length is greater than twice the diameter of the bone, failure can
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Injury: the British Journal of Accident Surgery Vol. 1 O/No. 2
Fig. 19. Fractures of both forearm bones with severe comminution of radius,
Fig. 20. Radiograph showing delayed union of the radius and malunion of the ulna.
sometimes occur from the presence of an unrecognized 'butterfly' fragment. It is suggested that in inexperienced hands it is safer with tibial fractures to use a neutralization plate as a routine addition to interfragmentary compression with screws. This is particularly important as the AO manuals give very little up-to-date advice on the use of external splintage for these fractures in the immediate postoperative period. The system is based on the principle of early joint movement and to the uninitiated this might indicate a total abandonment of all external splintage. One of the failures of fixation was associated with bending of the implant and was due to the mistaken use of semi-tubular plates to fix both forearm bones. Although their use on the ulna was suggested in the AO manual they are unsuitable for fractures of both bones, particularly when the forearm is not to be protected by the use of postoperative plaster immobilization. The 2 refractures occurred when the implant was removed earlier than normally suggested, because of the complication of deep infection. In both patients the plates were removed at 9 months when healing by external callus would normally be well established. The refractures, following relatively minor trauma, may have been the result of inhibition of primary bone union by the infection, or may suggest that this is a slower, less efficient process. There is insufficient information in the literature to guide the inexperienced as to the ideal time for implant removal. This must be planned to avoid the risks of refracture by premature removal, while avoiding failure of maturation and strengthening in the fracture
repair due to the continued presence of a rigid implant. The delayed union and non-union rate of 15 per cent seems high, but the majority of cases were associated with the other complications of infection and loss of fixation. Similarly high figures occur in other series, such as that of Dodge and Cady (1972), who reported a 13 per cent non-union rate in forearm fractures. In their series, as in the tibial fractures reported by Batten et al. (1978) (pp. 108-114), the delayed union rate was highest with comminuted fractures. In this type of fracture, compression fixation may be technically difficult, mechanically inefficient and may require the insertion of additional bone grafts. These fractures should only be treated by this method when sufficient experience has been gained with its use for much simpler injuries. The one case of delayed union which did not require grafting illustrates this point well. The patient had sustained a fracture of both forearm bones with severe comminution of the radius (Fig. 19) and was treated by attempted primary internal fixation. Unfortunately the more difficult radial fracture was plated first and because the technical difficulties resulted in prolonged tourniquet time, the ulna was left without fixation (Fig. 20). Delayed union was the inevitable result, but could possibly have been avoided by fixing the ulna fracture first and combining this with primary bone grafting of the radius to maintain length when this was plated. The presence of radiological callus around more than 50 per cent of the fractures suggests that in only a small proportion was true com~res-
Fisher and Hamblen : Compression Fixation of Long Bones
sion fixation achieved. However, a significant number of patients were managed by delayed fixation and in these the callus could have resulted from periosteal stripping, either at the time of fracture or during the period of failed conservative management. Several fractures demonstrated the haze of 'irritable' callus described by proponents of the AO method as evidence of failed fixation. In some patients a review of the immediate postoperative radiographs clearly showed the presence of a visible fracture line, suggesting that compression had been inadequate or that the fracture had been incompletely reduced. Although the results reported here are not intended to represent an assessment of the AO method of internal fixation as compared with conventional methods, they indicate some of the problems that can be encountered with this technique. Many of these failures were due to inexperience in the application of the technique to a wide variety of fractures and failure to recognize the importance of the biological component in fracture healing, namely the quality of the bone itself. It is clear that the AO technique provides rigid fixation augmented by wellengineered instrumentation, but it also demands a full awareness of the principles and pitfalls of the method, otherwise ill-considered surgery will lead to undeserved criticism of the technique (Wade, 1970). In conclusion, attention should be drawn again to the excellent advice contained in the Editorial of this journal (1977) on the subject. It stressed the need for attendance at instructional courses and the requirement for a full range of equipment. It also emphasized the importance of careful study of the basic manuals, though this illustrates one deficiency which requires correction. That is the paucity of papers in the English literature describing the results and complications from large series. The experience of the innovators is recorded by the AO documentation centre but in a large part is only available in the German literature. It is suggested that all centres using these techniques of internal fixation should maintain a careful record of all the fractures treated by the method. Any complications could then be evaluated against a detailed record of the operative technique used. The completion of a suitable pro forma should be the price exacted
107
from every surgeon using this complex equipment if its place in the surgical armamentarium is to be clearly defined. Experience must be gained by operating on the simpler fractures first, and needs to be acquired by the whole theatre staff and not just the operating surgeon. The introduction of courses specifically designed for theatre nursing staffis a very welcome development, as familiarization with the instruments and technique should shorten the operating time and may even help the theatre staff to guide the less experienced junior surgeon. REFERENCES Allg~Swer M., Ehrsam R., Ganz R. et al. (1969) Clinical experience with a new compression plate ('DCP'). Acta Orthop. Scand. Suppl. 125, 46. Batten R. L., Donaldson L. J. and Aldridge M. J. (1978) Experience with the AO method in the treatment of fresh fractures of the tibial shaft. Injury 10, 108. Burwell H. N. (1971) Plate fixation of tibial shaft fracture. J. Bone Joint Surg. 53B, 258. Charnley J. (1972) The Closed Treatment o f Common Fractures, 3rd ed. Edinburgh, Livingstone. Dodge H. S. and Cady G. W. (1972) Treatment of fractures of the radius and ulna with compression plates. A retrospective study of 119 fractures in 78 patients. 3". Bone Joint Surg. 54A, 1167. Editorial (1977) Internal fixation. Injury 8, 157. Hicks J. H. (1971) High rigidity in fracture of the tibia, lnjury 3, 121. Mtiller M. E. (1963) Internal fixation for fresh fractures and for non-union. Proc. R. Soc. Med. 56, 455. MiJller M. E., Allg~SwerM. and Willenegger H. (1970) Manual o f Internal Fixation. Berlin, SpringerVerlag. Nicoll E. A. (1964) Fractures of the tibial shaft. J. Bone Joint Surg. 46B, 373. Olerud S. and Karlstrtim G. (1972) Tibial fractures treated by AO compression osteosynthesis. Experiences from a five-year material. Acta Orthop. Scand. Suppl. 140. Perren S. M., Huggler A., Russenberger M. et al. (1969) The reaction of cortical bone to compression. Acta Orthop. Scand. Suppl. 125, 19. Sarmiento A. (1967) A functional below-the-knee cast for tibial fractures. J. Bone Joint Surg. 49A, 855. Smith J. E. M. (1974) Results of early and delayed internal fixation for tibial shaft fractures. J. Bone Joint Surg. 5615, 469. Wade P. A. (1970) Editorial: ASIF Compression has a problem. J. Trauma 10, 513.
Requestsfor repriatsshouhlbe addressedto: Mr W. D. Fisher,UniversityDepartmentof Orthopaedics,WesternInfirmary,Glasgow, Scotland.
99.
Problems and pitfalls of compression fixation of long bone fractures: a review of results and complications W. D. Fisher and D. L. Hamblen University Department of Orthopaedics, Western Infirmary, Glasgow Summary
The complications encountered in the compression fixation of 70 cortical long bone fractures are reviewed. The results represent the initial experience with the AO fixation equipment following its introduction to a centre with staff relatively untrained in the technique. Infection was the most serious complication, with a deep sepsis rate of 10.5 per cent, but fixation failure, delayed union and refracture also occurred. The various problems are discussed in detail and suggestions are made as to how they can be avoided.
INTRODUCTION CONTROVERSYstill exists over the place of internal fixation in the routine management of long bone fractures. To justify acceptance, the results of its use must compare favourably with the good results reported from the conservative management of both lower and upper limb fractures (Nicoll, 1964; Charnley, 1972). It also increases the risk of infection, which is still a common complication of internal fixation, particularly in the presence of an open fracture (Burwell, 1971; Smith, 1974). However, the techniques of internal fixation have been improved with the development of more rigid implants (Hicks, 1971) and the concept of compression fixation introduced by the Swiss AO Group (MiJller, 1963; Allg6wer et al., 1969; Mtiller et al., 1970). These developments have been based on the animal experimental work on fracture healing by Perren et al. (1969) and there has been a renewal of interest in the technique. The aim of AO is to achieve an early return to full function of the injured limb by accurate anatomical reduction and rigid internal fixation to allow early mobilization. The instru-
mentation and implants for this method are available in an increasing number of orthopaedic units, but the techniques are often used by orthopaedic surgeons and trainees with little practical experience in their application. It was felt that an early critical review of the results following the introduction of the technique to one centre would be of value in assessing its efficacy for general use. To simplify the study, it was confined to cortical fractures in the shafts of long bones with the exclusion of metaphyseal and epiphyseal injuries.
PATI E NTS Between October 1973 and March 1976 70 patients with long bone fractures were treated by compression fixation in the Accident Unit of the Western Infirmary, Glasgow. The distribution of fractures was as follows: tibia, 40 patients; femur, 6 patients; forearm, 15 patients with involvement of both. bones, 7 with isolated fractures of the radius and 2 of the ulna (total 24). While primary internal fixation was the treatment of choice in almost all patients presenting with displaced fractures of the forearm bones, it was only used in one-third of all fresh fractures of the tibia and was rarely indicated for fractures of the femoral shaft. When internal fixation was required in the femur, medullary nailing was preferred, except for delayed union of fractures in the distal third of the femoral shaft. Only onethird of the patients had sustained their injuries in high velocity road traffic accidents, the remaining fractures being sustained at work, during sport or in domestic accidents. Sixteen of
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Injury : the British Journal of Accident Surgery Vol. 10/No. 2
the tibial fractures were open (40 per cent), but no open fractures occurred in the other bones. The average age of the patients was 40.5 years (range 12-90 years). There were 2 deaths in the series. One was a 90-year-old woman with a spiral fracture of the femur who died 6 h after plating of the fracture, and the second patient was a 56-year-old woman with a tibial fracture who died at 16 weeks of unrelated causes. Two other patients were excluded from the series. One man with a tibial fracture was lost to follow-up after 6 weeks and one man required early amputation for ischaemia of the foot after internal fixation of a tibial fracture. The remaining 66 patients were followed until radiological union had occurred or clinical function was satisfactory. The mean length of follow-up was 1 year (range 3 months to 3 years).
Technique of fixation In 55 patients fixation of the fracture was achieved by means of a plate, supplemented in some cases by a compression screw. Tension was applied to the plate either by means of an external tensioning device or by the insertion of off-set screws in a dynamic compression plate (DCP) (AIlg6wer et al., 1969). The other 15 patients with more oblique or spiral fractures of the tibial shaft were treated by compression screws alone. It was not standard practice to dispense entirely with external splintage after fixation of the fracture. All tibial fractures were protected after wound healing by a patellar weight-bearing plaster cast for 6-12 weeks (Sarmiento, 1967), allowing knee mobility. After fixation of most forearm fractures the arms were allowed to move freely, although in 7 patients (29 per cent) a long arm cast was used for 2-8 weeks after operation. Fractures of the shaft of the femur were treated in splintage until muscular control of the limb was restored. Postoperative suction wound drainage, though recommended by AO, was not used routinely. Antibiotic cover during surgery and for the first postoperative week was used in 50 per cent of cases, including all open fractures. It was not the policy to remove implants routinely, except in the presence of a complication such as loosening, infection, previous infection or when subcutaneous placement of the implant was causing irritation. R ES U L T S
The radiological and clinical results were reviewed in 66 of the 70 patients. It was not possible to assess the state of union on clinical grounds in the presence of rigid internal fixation. The radio-
logical assessment of union was often difficult, because the presence of a large implant made it difficult to see the fracture line clearly and union frequently occurred without visible callus. This latter phenomenon is said to be the expected result of primary bone healing in a fracture correctly treated by compression fixation. However, in this series, 50 per cent of cases showed radiological union with visible periosteal callus. In many cases this was observed when the functional result was otherwise excellent and the compression fixation apparently adequate. In 53 patients (80 per cent) union occurred without further intervention. In all but 3 of the 34 patients with tibial fractures full ambulation without assistance was possible at an average of 16 weeks. One further patient regained normal movement but remained chairbound from other causes and two patients required assistance in walking because of other injuries. The 15 patients who had sustained forearm fractures regained functional use of the arm in an average of 11 weeks. All 4 uncomplicated femoral fractures regained normal function at an average of 18 weeks. Only 32 of the patients (60 per cent) had a full range of movement in the adjacent joints at the time of final review and 4 patients (8 per cent) had limitation of joint movement of more than 60 per cent. COMPLICATIONS
Complications preventing successful primary healing of the fracture after fixation occurred in 13 patients (20 per cent) and are listed in Table I.
Infection This was the commonest complication encountered and in the 67 patients reviewed before 3 months there were 7 deep infections, a rate of 10"5 per cent. Only 1 occurred in a forearm fracture, the other 6 were in the tibia, giving a deep infection rate in this group of 15 per cent. Five of the infected fractures were closed and only 2 were open. Deep infection usually occurred within a few days of operation, presenting with pain, erythema, discharge of pus and later radiological evidence of periosteal reaction and resorption around the implant. In 6 other patients (9 per cent) there was evidence of delayed wound healing or superficial infection, but these all healed with antibiotic therapy without further complications or radiological changes. However, if these are added to the deep established infections, the overall infection rate becomes 19-5 per cent. It was surprising that infection was not more frequent in open fractures, where the rate
Fisher and Hamblen : Compression Fixation of Long Bones
101
Table I. C o m p l i c a t i o n s o f internal f i x a t i o n Complication Infection Superficial Deep Failure of f i x a t i o n Screws
Plate Implant failure Refracture Delayed or n o n - u n i o n Reoperation
Tibia
Radius and ulna
Femur
Total
%
4 6
2 1
---
6 7
9 10-5
3
--
--
3
1
1
1
3
-1 6 7
1 1 3 3
--1 1
1 2 10 11
Fig. I. Fig. 2. Fig. 1. Comminuted compound fracture of distal tibia and fibula. Fig. 2. Radiograph 2 weeks after internal fixation and bone grafting of fractures. Fig. 3. Radiograph after removal of plate and screws for persistent osteitis of tibia. was 25 per cent (2 superficial and 2 deep in 16 patients). Deep infections were treated on diagnosis with antibiotics and 3 healed without further symptoms, though the implant was removed later in 2 of these patients. In another 2 patients refracture occurred following the removal of the implants at 32 weeks after apparently successful antibiotic treatment. In the remaining 2 patients with infected tibial fractures the plate was removed when it became loose and bone grafting was carried out. One of these patients had sustained an almost complete degloving injury of the skin of the leg, necessitating repeated skin grafting before the tibial fracture finally united after 18 months. The other patient was an elderly man with a
j
10"5 3 15 15-7
Fig. 3.
severely comminuted fracture of the distal tibia sustained when he was run over in a traffic accident (Fig. 1). Stability was achieved by plating both the tibia and fibula with the addition of a large iliac crest bone graft to the tibial defect (Fig. 2). A persistent pseudomonas osteitis developed, requiring removal of the tibial plate and further grafting (Fig. 3). Despite this, further resorption and collapse occurred (Fig. 4) leading to below-knee amputation after 22 months. Fixation failure There were 6 patients in whom failure of fixation occurred without evidence of implant breakage or deep infection. Loss of fixation occurred in 3 of the 15 tibial fractures treated by compression lag
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=
bone grafting, while in the third, bone grafting was augmented by compression plating of the fracture with a satisfactory result. In 3 patients loosening of a plate occurred following an apparently satisfactory compression fixation. A review of the initial radiographs in 2 of these patients suggested that 1 screw had been malpositioned and had probably entered the fracture line, thereby weakening the original fixation. The third patient was an elderly woman who sustained a spiral fracture of the femoral shaft below a malaligned hip prosthesis (Fig. 7). This required treatment by a lag screw and fixation with a compression plate (Fig. 8) to permit early mobilization, but loosening occurred after 10 weeks (Fig. 9). The fixation of the plate to the proximal fragment can be seen to be inadequate as it is so near to the hip implant. An additional factor may have been the osteoporosis associated with chronic joint disease. Union occurred in splintage after removal of the plate and after bone grafting.
Fig. 4. Established non-union and chronic osteitis of tibia and fibula.
Fig. 5. Fig. 6. Fig. 5. Spiral fracture of tibia treated with interfragmentary compression screws. Fig. 6. Radiograph showing loosening of screws and refracture at 6 weeks following minor trauma. screws alone (Fig. 5), with loosening of the screws and refracture following mobilization of the limb out of plaster (Fig. 6). In 2 of these patients union was achieved by removal of the screws and
Implant failure In one obese but energetic patient, bending of an implant occurred with failure of fixation. His fractures of both forearm bones were fixed "by
Fisher and Hamblen : Compression Fixation of Long Bones
103
function including full rotation. Delayed union or non-union Delayed union or non-union occurred in 10 patients (t5 per cent). The majority of these instances were attributable to the other complications already described. Two were associated with deep infections and 7 with failure of the implant or its fixation. Further bone grafting was required in 9 patients, while prolonged immobilization resulted in union of the remaining forearm fracture after 36 weeks.
Refracture
Fig. 7. Radiograph of spiral fracture of femur below a hip prosthesis.
Refracture occurred in 2 patients following early removal of the implants. One closed comminuted fracture of the tibia (Fig. 13) became infected following fixation with a dynamic compression plate. The plate was removed at 32 weeks because of continued discomfort, though radiographs at this stage (Fig. 14) appeared to show sound bony
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Fig. 8.
Fig. 9. Fig. 8. Femoral fracture fixed with an interfragmentary screw and compression plate. Fig. 9. Radiograph showing plate loosening and refracture at I0 weeks. means of two semi-tubular plates (Fig. 10) without the protection of external splintage. Following a period of over-use during motorcycle racing, bending of the radial plate occurred (Fig. 11) and resulted in delayed union of the fracture. Removal of the plate with bone grafting and recompression o f the radius using a heavier plate was combined with excision of the lower end of the ulna (Fig. 12). This resulted in satisfactory union of the radius and recovery of normal forearm
union. Four weeks later, following a minor stumble, refracture occurred through the site of original injury (Fig. 15). The second patient had the plating of fractures of both forearm bones complicated by deep infection (Fig. 16), requiring removal of the implants at 32 weeks (Fig. 17). Two weeks later the bones refractured through one of the screw holes in the radius and at the site of the original fracture in the ulna (Fig. 18). Union occurred following a further period of
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Fig. 10. Fig. 11. Fig. 12. Fig. 10. Radiograph of forearm fractures fixed with. two semi-tubular plates. Fig. 11. Bending of radial plate with loosening of screws and delayed union. Fig. 12. Radiograph following bone grafting, replating of radius and excision of distal ulna.
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Fig. 13. Fig. 14. Fig. 15. Fig. 13. Radiograph following fixation of a transverse fracture of the tibia with a DCP plate. Fig. 14. Apparent radiological union of tibia at 32 weeks. Fig. 15. Radiograph showing refracture of tibia following removal of plate. immobilization but another refracture of the radius occurred through a screw hole 5 months after the removal of plaster.
DISCUSSION When the AO compression fixation equipment was introduced to our centre it was to be expected that such a novel and beautifully instrumented system would prove irresistible to orthopaedic surgeons at every level of training. Any attempt to
limit its use to selected personnel was felt to be impracticable, despite the fact that only one consultant had attended the Davos course. Some of the other members of staff had received instruction at shorter courses held in the United Kingdom. The expected result was that 18 different surgeons performed the first 70 long bone fixations. However, the 6 members of the consultant staff carried out 40 (57 per cent) of the operations and supervised most of the others.
Fisher and Hamblen : Compression Fixation of Long Bones
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Fig. 16. Fig. 17. Fig. 18. Fig. 16. Radiograph showing plated fractures of both forearm bones complicated by infection. Fig. 17. Appearances of radius and ulna following removal of plate. Fig. 18. Radiograph showing refracture through the ulna and radius screw hole. The inevitable lack of familiarity with the techniques and instruments must have contributed to the high complication rate, which was unrelated to the seniority of the operating surgeon. The reoperation rate of 15.7 per cent is not much higher than the 10"5 per cent rate in a large series of tibial fixations carried out by more experienced surgeons(Battenet al., 1978) (see pp. 108-114) and less than the 19 per cent in another series (Olerud and Karlstr6m, 1972). The severity of the initial injury varied widely and fixation was delayed in a significant proportion of fractures following an initial trial of conservative treatment. Twelve (50 per cent) of the forearm fractures and 10 (25 per cent) of the tibial fractures were fixed following failure of closed reduction and plaster immobilization. The most serious complication was infection, and this reached an unacceptably high level of 10-5 per cent for deep sepsis, with a 19.5 per cent overall infection rate. As all the operations were carried out in new operating theatres, under apparently ideal conditions, this rate must reflect factors other than the operating environment. It could be related to the prolonged operating time and excessive tissue damage associated with the technical inexperience of the operating surgeon, assistants and theatre nurses. Improved training and increasing experience should decrease the infection rate, but what other measures can be utilized to reduce it ? Routine suction drainage of wounds is recommended by AO but was used infrequently in this series. Drainage was used in only 4 forearm fractures and 4 tibial fractures,
though 4 of the 6 femoral fractures were drained. Although 2 of the deep tibial infections occurred in drained cases, the elimination of post-fixation haematoma should form a logical routine part of the management. The other possible method is the use of prophylactic antibiotics as a means of reducing the postoperative infection rate. In this series they were used routinely for all open fractures of the tibia, but despite this the infection rate in this group reached 25 per cent. In closed fractures of the tibia they were used in 10 of the patients (40 per cent), but again this group included 2 deep and 2 superficial infections. Decreased infection rates have been reported with prophylactic antibiotics and it could be argued that they should be used by the less experienced surgeon until his technique has been perfected and the operating time thereby reduced. Infection must be regarded as a very serious complication of the internal fixation of fractures. Even when it responds to antibiotic therapy, it may still result in loosening of the implant, necessitating its premature removal, or may interfere with the process of primary bone healing with an increased risk of refracture. Failure of fixation, which occurred in 7 patients (10.6 per cent), must reflect poor technique or the incorrect choice of implant. When the patients treated by compression screws alone were considered as a separate group, the failure rate rose to 20 per cent (3 out of 15). Even when this technique is used for the correct type of spiral fracture, when the fracture length is greater than twice the diameter of the bone, failure can
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Fig. 19. Fractures of both forearm bones with severe comminution of radius,
Fig. 20. Radiograph showing delayed union of the radius and malunion of the ulna.
sometimes occur from the presence of an unrecognized 'butterfly' fragment. It is suggested that in inexperienced hands it is safer with tibial fractures to use a neutralization plate as a routine addition to interfragmentary compression with screws. This is particularly important as the AO manuals give very little up-to-date advice on the use of external splintage for these fractures in the immediate postoperative period. The system is based on the principle of early joint movement and to the uninitiated this might indicate a total abandonment of all external splintage. One of the failures of fixation was associated with bending of the implant and was due to the mistaken use of semi-tubular plates to fix both forearm bones. Although their use on the ulna was suggested in the AO manual they are unsuitable for fractures of both bones, particularly when the forearm is not to be protected by the use of postoperative plaster immobilization. The 2 refractures occurred when the implant was removed earlier than normally suggested, because of the complication of deep infection. In both patients the plates were removed at 9 months when healing by external callus would normally be well established. The refractures, following relatively minor trauma, may have been the result of inhibition of primary bone union by the infection, or may suggest that this is a slower, less efficient process. There is insufficient information in the literature to guide the inexperienced as to the ideal time for implant removal. This must be planned to avoid the risks of refracture by premature removal, while avoiding failure of maturation and strengthening in the fracture
repair due to the continued presence of a rigid implant. The delayed union and non-union rate of 15 per cent seems high, but the majority of cases were associated with the other complications of infection and loss of fixation. Similarly high figures occur in other series, such as that of Dodge and Cady (1972), who reported a 13 per cent non-union rate in forearm fractures. In their series, as in the tibial fractures reported by Batten et al. (1978) (pp. 108-114), the delayed union rate was highest with comminuted fractures. In this type of fracture, compression fixation may be technically difficult, mechanically inefficient and may require the insertion of additional bone grafts. These fractures should only be treated by this method when sufficient experience has been gained with its use for much simpler injuries. The one case of delayed union which did not require grafting illustrates this point well. The patient had sustained a fracture of both forearm bones with severe comminution of the radius (Fig. 19) and was treated by attempted primary internal fixation. Unfortunately the more difficult radial fracture was plated first and because the technical difficulties resulted in prolonged tourniquet time, the ulna was left without fixation (Fig. 20). Delayed union was the inevitable result, but could possibly have been avoided by fixing the ulna fracture first and combining this with primary bone grafting of the radius to maintain length when this was plated. The presence of radiological callus around more than 50 per cent of the fractures suggests that in only a small proportion was true com~res-
Fisher and Hamblen : Compression Fixation of Long Bones
sion fixation achieved. However, a significant number of patients were managed by delayed fixation and in these the callus could have resulted from periosteal stripping, either at the time of fracture or during the period of failed conservative management. Several fractures demonstrated the haze of 'irritable' callus described by proponents of the AO method as evidence of failed fixation. In some patients a review of the immediate postoperative radiographs clearly showed the presence of a visible fracture line, suggesting that compression had been inadequate or that the fracture had been incompletely reduced. Although the results reported here are not intended to represent an assessment of the AO method of internal fixation as compared with conventional methods, they indicate some of the problems that can be encountered with this technique. Many of these failures were due to inexperience in the application of the technique to a wide variety of fractures and failure to recognize the importance of the biological component in fracture healing, namely the quality of the bone itself. It is clear that the AO technique provides rigid fixation augmented by wellengineered instrumentation, but it also demands a full awareness of the principles and pitfalls of the method, otherwise ill-considered surgery will lead to undeserved criticism of the technique (Wade, 1970). In conclusion, attention should be drawn again to the excellent advice contained in the Editorial of this journal (1977) on the subject. It stressed the need for attendance at instructional courses and the requirement for a full range of equipment. It also emphasized the importance of careful study of the basic manuals, though this illustrates one deficiency which requires correction. That is the paucity of papers in the English literature describing the results and complications from large series. The experience of the innovators is recorded by the AO documentation centre but in a large part is only available in the German literature. It is suggested that all centres using these techniques of internal fixation should maintain a careful record of all the fractures treated by the method. Any complications could then be evaluated against a detailed record of the operative technique used. The completion of a suitable pro forma should be the price exacted
107
from every surgeon using this complex equipment if its place in the surgical armamentarium is to be clearly defined. Experience must be gained by operating on the simpler fractures first, and needs to be acquired by the whole theatre staff and not just the operating surgeon. The introduction of courses specifically designed for theatre nursing staffis a very welcome development, as familiarization with the instruments and technique should shorten the operating time and may even help the theatre staff to guide the less experienced junior surgeon. REFERENCES Allg~Swer M., Ehrsam R., Ganz R. et al. (1969) Clinical experience with a new compression plate ('DCP'). Acta Orthop. Scand. Suppl. 125, 46. Batten R. L., Donaldson L. J. and Aldridge M. J. (1978) Experience with the AO method in the treatment of fresh fractures of the tibial shaft. Injury 10, 108. Burwell H. N. (1971) Plate fixation of tibial shaft fracture. J. Bone Joint Surg. 53B, 258. Charnley J. (1972) The Closed Treatment o f Common Fractures, 3rd ed. Edinburgh, Livingstone. Dodge H. S. and Cady G. W. (1972) Treatment of fractures of the radius and ulna with compression plates. A retrospective study of 119 fractures in 78 patients. 3". Bone Joint Surg. 54A, 1167. Editorial (1977) Internal fixation. Injury 8, 157. Hicks J. H. (1971) High rigidity in fracture of the tibia, lnjury 3, 121. Mtiller M. E. (1963) Internal fixation for fresh fractures and for non-union. Proc. R. Soc. Med. 56, 455. MiJller M. E., Allg~SwerM. and Willenegger H. (1970) Manual o f Internal Fixation. Berlin, SpringerVerlag. Nicoll E. A. (1964) Fractures of the tibial shaft. J. Bone Joint Surg. 46B, 373. Olerud S. and Karlstrtim G. (1972) Tibial fractures treated by AO compression osteosynthesis. Experiences from a five-year material. Acta Orthop. Scand. Suppl. 140. Perren S. M., Huggler A., Russenberger M. et al. (1969) The reaction of cortical bone to compression. Acta Orthop. Scand. Suppl. 125, 19. Sarmiento A. (1967) A functional below-the-knee cast for tibial fractures. J. Bone Joint Surg. 49A, 855. Smith J. E. M. (1974) Results of early and delayed internal fixation for tibial shaft fractures. J. Bone Joint Surg. 5615, 469. Wade P. A. (1970) Editorial: ASIF Compression has a problem. J. Trauma 10, 513.
Requestsfor repriatsshouhlbe addressedto: Mr W. D. Fisher,UniversityDepartmentof Orthopaedics,WesternInfirmary,Glasgow, Scotland.