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Complications and failures of the ESIN technique
Injury, Int. J. Care Injured (2005) 36, S-A78—S-A85
Complications and failures of the ESIN technique Theddy F. Slongo Department of Pediatric Surgery, Children’s University Hospital, Bern, Switzerland
KEYWORDS: Elastic stable intramedullary nailing; child; rotational failure; corkscrew phenomenon; shortening; biomechanical properties; insertion point; femur fracture, humerus fracture; tibia fracture; forearm fracture.
Summary1 Only knowledge of the possible failures and complications of a method allows its correct application. This also applies to ESIN (Elastic Stable Intramedullary Nailing), which has been promoted as a simple procedure. Most failures occur through neglect of the important biomechanical principles, and by obvious technical errors. The combination of both causes of failure can lead to serious complications in this method, which is generally regarded as “benign”. These complications include serious rotational deformity, leg shortening, and growth disorders from growth plate injuries. A fundamental distinction must be made between intraoperative and postoperative problems and true complications. The present paper is intended to contribute towards avoiding such errors and detecting errors as early as possible during surgery in order to correct them.
Introduction Any method is only as good as its application, applies particularly to Elastic Stable Intramedullary Nailing (ESIN). It is a relatively simple method, but even simple things have to be learned and performed correctly. The simplicity of the method and of the implant can mislead anyone who neglects to study and follow the basic principles of the method, and fails to consider the indications and contraindications [4, 6, 9, 10]. There is no excuse for poorly performed nailing and causing completely avoidable problems [5, 11]. However, analysis of the failures clearly shows that it is not a question of failures due to the implant, but instead ignoring the basic principles of technique. The “benign nature” of ESIN is, however, largely forgiving of incorrect application. Moreover, the corrective potential of the child’s skeleton contributes towards the healing of fractures that have received suboptimal treatment. A follow-up study of all of our femoral fractures treated with
1
Abstracts in German, French, Italian, Spanish, Japanese, and Russian are printed at the end of this supplement.
0020–1383/$ — see front matter ß 2004 Published by Elsevier Ltd. doi:10.1016/j.injury.2004.12.017
ESIN showed that surgeons with little experience of this method showed significantly higher rates of problems and complications. On the other hand, however, long-term analysis showed that practically all these early problems remodelled, and the end results were always good. This should not mislead us into thinking that the method need not be performed correctly, particularly because the indication is being increasingly widened, with unstable fractures being treated with this method [8]. With over 18 years’ continuous experience with this method, including running more than 50 workshops, and collecting comprehensive documentation, this paper discusses the most frequent problems and errors. In so doing, we will specifically address systemrelated and fracture-related problems separately.
Principle failures Biomechanical properties In contrast to solid nails, which are locked by means of screws for axial as well as rotary stability, the same principle is achieved in ESIN through a so-called
Complications and failures of the ESIN techninque
S-A79
Fig. 2: (a) No inner contact to the cortex layer; (b) correct contact to the inner cortex layer.
Fig.1: Schematic representation of the classic 3-point support: The greater and more extended the internal contact, the better the stability.
“3-point support” (Fig. 1). This principle must be strictly adhered to [4, 10]. The greater the instability of the fracture, the more the inner bracing must be increased.
Most errors that are made in relation to biomechanics are based on a lack of internal support. The nails either touch the inner surface of the cortex too little, or not at all, because of insufficient pre-bending of the nails. By pre-bending the nails, this inner contact pressure can be markedly increased, which is more important than the proximal and distal anchor points (Fig. 2). Only through correct tensioning of the nails can the dynamic principle of this method
Fig. 3: Typical example of a combination of errors: nails too thin, several crossovers (corkscrew phenomenon), no inner contact. When first subjected to loading, this led to loss of position, which was repositioned with the nails in place under a general anesthetic, and with a spica cast for 3 weeks.
S-A80
fulfill its potential. This principle is based on the circular muscle mantle and the restoring force of the pre-stressed nails, which repeatedly bring the fragments back into an anatomical position. Care should be taken to ensure that the per-bending of both nails is symmetrical over the same length [8]. In principle, two nails of the same thickness and similarly pre bended should always be used. Nails of differing thicknesses with the same pre-bending have a different “restoring force”, which pushes the proximal fragment into a varus or valgus position. For reasons that are not entirely clear, this basic principle is repeatedly ignored. For the sake of completeness, however, it should be mentioned that this asymmetrical effect is undoubtedly desirable, when the fracture or soft tissues have a tendency to develop varus or valgus.
T.F. Slongo
Nail diameter In general, the nail diameter should be selected to correspond to between one third and 40% of the narrowest medullary space diameter [4, 9, 10]. The sole exception is the forearm, where only one nail is inserted per bone. The thickness should be 60% of the medullary space, since both bones are considered as one. In the upper extremity, nails that are too thin cause minimal problems whereas in the lower extremity unacceptable problems occur, even in transverse fractures [11]. These problems include axial malalignment, which requires correction followed by additional plaster immobilization. Occasionally, replacement of the nails is required (Fig. 3). As already mentioned, differing nail thicknesses also lead to axial deformity, which causes to functional and cosmetic impairment.
Insertion point
Fig. 4: (a) Defective positioning of the insertion points, asymmetrical, leads to unequal tension; (b) correct position.
Incorrect positioning of the nail insertion points can have various negative effects for the [3]: 1. Insertion points that do not lie opposite one another greatly influence the biomechanics (differing internal tension) and thus the stability of the fracture fixation (Fig. 4, 5). One exception is the so-called monolateral treatment (anterograde nailing of the femur or anterograde and retrograde nailing of the humerus), which
Fig. 5: Insertion point too high, and asymmetrical. Besides the inadequate bracing, the high and long lateral nail leads to muscle and skin problems.
Complications and failures of the ESIN techninque
is, however, only used for distal metaphyseal femoral fractures, supracondylar fractures and proximal humeral fractures. 2. In the distal femur in particular, insertion points that are too diaphyseal lead to severe muscle irritation. Moreover, during insertion and more so during removal of the nail, the musculature is further damaged (Fig. 5). 3. Without sufficient preparation, injury to the superficial branch of the radial nerve can occur over the distal radius [11]. In the same way, injuries to the ulnar nerve can occur at the proximal ulnar insertion point. Both these problems can be avoided by selecting—as is currently recommended—a dorsal insertion point on the distal radius, and a radial insertion point on the proximal ulna. 4. One of the errors with the most serious consequences is injury to growth plates due to insertion points that are too close to the epiphysis. Injury to the perichondral ring occurs at the time of formation of the entry point and also the position of the nail after insertion. We know of cases that have led to growth arrest requiring surgical correction (Fig. 6).
Fig. 6: Fittings of this type lead to injury to the perichondral ring and thus to growth disorders.
S-A81
Fig. 7: Nail cut off too long in conjunction with heavy curvature leads to blocking of the knee and to skin irritation, even perforations.
Fig. 8: Multiple turning of the nail leads to the nails twisting, and to loss of inner bracing, the so-called “corkscrew phenomenon”.
S-A82
5. Finally, nails that left too long lead to severe skin irritation and even skin breakdown [11]. In the distal femur, the ileotibial tract can be blocked, thus inhibiting knee flexion (Fig. 7).
“Corkscrew phenomenon” Difficulties with fracture reduction as well as advancing the second nail may tempt the surgeon to rotate the nail more than 180°. This will lead to one nail being wound around the other. This process is called the “corkscrew phenomenon”. This reduces the effective internal tension of the two nails, which then act as a simple central nail, which is neither rotationally nor axially stable. This phenomenon must be detected using the image amplifier and avoided at all costs. Once the phenomenon has been detected, the nail in question must be removed during the same operation and replaced by a correctly placed one (Fig. 8). In the following sections, fracture-specific errors will be described in further detail. The principal problems that have already been mentioned must be borne in mind at all times, and every effort made to avoid them [1, 2, 3, 5].
Fig. 9: A medial nail that is inserted far in a proximal direction can very easily perforate on the calcar if rotation of the tip is ignored. For this reason, good fluoroscopy is an important prerequisite for this method.
T.F. Slongo
Failures femoral nailing The three most common errors are: Perforation of the medial nail through the calcar Due to the procurvatum of the femur, the medial nail continually moves in a dorsal direction towards the calcar. Here, it can easily perforate the thin cortex. Therefore it is essential to monitor nail progression using an image intensifier. If the nail tip is directed dorsally and makes contact with the calcar, the nail must be retracted and rotated 90° in a ventral direction so that it can progress without perforation (Fig. 9). Failure to catch the proximal fragment In long spiral fractures, but also in transverse fractures, the surgeon may not realize that one of the nails has not caught the proximal fragment. This is difficult to detect clinically, since the stability is often initially good, due to the subperiostal position of the nail. This error is mainly due to the poor positioning of fluoroscope, and failures to obtained orthogonal images in two views 90° to each other (Fig. 10).
Fig. 10: Failure to catch the proximal fragment. This error is due to a poor fluoroscopy technique which does not allow fluoroscopy in both planes.
Complications and failures of the ESIN techninque
Inappropriate nail thickness The correct nail thickness (40%) is required for adequate stability and optimum biomechanics. Both nails must have identical thickness and curvature. Any mistake is particularly detrimental for the femur, since a second anesthesia is required either to replace the nails perform further reduction, or apply a spica cast (Fig. 3).
Failures of forearm nailing Incorrect treatment of forearm fractures by means of ESIN has, in principle, similar consequences to those that can be seen with conservative treatment. The greatest problem is malunions which leads to restricted function, particularly pronation and supination. Forearm deformity that does not remodeled can be a cosmetically disfiguring. The causes are first in selection of nails that are too thin (remember they should be 60% of the medullary space), and secondly lack of correct tensioning of the two nails against one another so that the interosseous membrane is tensioned appropriately. However, the greatest problems due the inappropriate use of ESIN methods for radial fractures in the
Fig. 11: Critical indication for the ESIN technique: The distal fragment is too short and is not held adequately by the nail. A malunion arose, which made a correction necessary. A better alternative here is an external fixator.
S-A83
distal third and metaphyseal regions which are not ideal indications for ESIN. In this region, the insertion point must be selected carefully on the dorsal aspect if possible. Furthermore, the nail must be considerably pre-bent near the end, so that it makes contact with the opposite cortex of the distal fragment. This will otherwise tilt the distal fragment in an ulnar direction (Fig. 11). It is generally accepted that one should not undertake removal of the metal before 4–6 months, and the fracture must be completely consolidated. It is unlikely refractures will be occur if this rule is followed. Thus, in contrast to plate osteosynthesis and conservative treatment, the risk of refracture is not due to the method but due to the surgeon who decides to remove the nails early. Anterograde nailing of the radius should be avoided since it can lead to injury of the deep branch of the radial nerve [11].
Failures of humeral nailing Since the decision for osteosynthesis of the humerus should be made cautiously, and problems of function and healing are almost unknown on the humerus,
Fig. 12: Due to the triangular cross-section of the tibia head, the nails follow the dorsal cortex layer. A recurvature arises. By turning the nail tips in a dorsal direction, the tibia can be straightened.
S-A84
T.F. Slongo
technical errors in osteosynthesis hardly ever have long-term effects. Nevertheless, some special features should be noted. In principle, humeral nailing is performed in a retrograde manner, monolaterally from lateral side. It is recommended to expose the distal humerus and to make the entry-points under direct vision. If the entry-points are made too high by closed means, there is a risk of damaging the radial nerve. Ulnar insertion should be avoided, to spare the ulnar nerve. The same risk of nerve damage exists in anterograde nailing for supracondylar humeral fractures [9, 12].
Failures of tibia nailing The treatment of tibial fractures by ESIN represents a great challenge, less so because of problems with reduction and placement of the nails but because of problems with the correct technique, which is always anterograde. The tibia is completely different from other limb segments. There are two reasons for this: First of all, the tibia lies completely eccentric in the musculature, which is of critical importance in ESIN. Secondly, the tibia is triangular in the crosssection, with the base dorsal, and the two sides aligned diagonally. The planes of the nail are thus likewise aligned in the diagonal, with the tension being directed in a dorsal direction. This arrangement
Fig. 13: Insufficient stability and blocking of the nail lead to pseudarthroses of the tibia, even in children.
leads to the situation that in the “normal” position of the nails, recurvatum of the tibia always occurs. This must be counteracted by turning the nail tips in a dorsal direction after definitive placement (Fig. 12). The literature, as well as our own experience, has shown that this segment is associated with the highest rate of problems and complications. The tibia is practically the only bone that develops nonunion or pseudarthrosis. The isolated tibial fracture must be mentioned above all in this context. An isolated tibial fracture is often accompanied by bowing of the fibula Stabilization of tibial fractures by ESIN often leads to slight distraction at the fracture side which blocks complete reduction (Fig. 13). This treatment can almost be regarded as a type of “pseudarthrosis model”. Retrograde nailing should be avoided, as distal insertion points damage the tendons, and use of ESIN methods for proximal tibial fractures is contraindicated. The pull of the patellar ligament is too great for the short segment of nails to hold the proximal fragment. Figure 14 illustrates the indications.
Discussion Only a few publications deal exclusively with the problems and complications of ESIN. Authors usually report only their own good results. In a multicenter
Fig. 14: Indications for ESIN on the tibia: Green is very suitable, orange is suitable to a limited extent, and red is unsuitable.
Complications and failures of the ESIN techninque
retrospective study of pediatric clinics in München, Regensburg, Graz, and Bern, of over 900 fractures treated using ESIN, it was nevertheless possible to demonstrate high rates of problems or complications [11]. In the majority of cases, however, these problems or postoperative complications do not influence the end result, which is very fortunate. This finding was also demonstrated in an as yet unpublished investigation of our own where it was shown that in the long-term only isolated problems such as length differences or axial errors were demonstrated. Just two cases had postoperative problems; the others had new problems that could not easily be attributed to the accident with difficulty. Time after time, analysis and discussion of problem cases show that the problem lies more with the surgeon than with the method. Thus the most frequent errors are made in establishing the appropriate treatment in relation to the biomechanics of the fracture, followed by technical errors such as the nails being too thin, “corkscrew phenomenon”, and lack of 3-point support. It is therefore necessary to continually emphasize that correct application is extremely important, and that the training that is increasingly on offer should be taken up. It is fatal to rely simply on the child’s potential for correction. If one decides on an operation, it should be carried out as carefully and correctly as possible. Only knowledge of all possible problems and complications will enable the surgeon to avoid them. It must, however, be emphasized that it is the ESIN technique that is often forgiving of our technical errors without serious complications for the child, making the method popular for a wide range of applications.
S-A85
References 1. Bettermann A, Kunze K, van Ackeren V (1989) Oberschenkelschafttrakturen im Wachstumsalter—Resultate nach Wachstumsabschluss. Unfallchirurgische Klinik der Universität Giessen. 2. Bowyer G, Clarke N.M.P, Gonzalez P (1995) Complications of pediatric femoral nailing. Bone Joint Surg; 77(4):666–667. 3. Braten M, Terjesen T, Rossvoll I (1993) Torsional deformity after intramedullary nailing of femoral shaft fractures. Measurement of anteversion angles in 110 patients. J Bone Joint Surg Br; 75(5):799–803. 4. Dietz HG, Schmittenbecher PP, Illig Intramedulläre Osteosynthese im Wachstumsalter. Urban & Schwarzenberg. 5. Flynn JM, Hresko T, Reynolds RA, et al (2001) Titanium elastic nails for pediatric femur fractures: a multicenter study of early results with analysis of complications. J Pediatr Orthop; 21(1):4–8. 6. Galpin RD, Willis RB, Sabano N (1994) Intermedullary nailing of pediatric femoral fractures. J Pediatr Orthop; 14(2):184– 189. 7. Heinrich SD, Drvaric D, Darr K et al (1992) Stabilization of pediatric diaphyseal femur fractures with flexible intramedullary nails (a technique paper). J Orthop Trauma; 6(4):452–459. 8. Linhart WE, Roposch A (1999) Elastic stable intramedullary nailing for unstable femural fractures in children: preliminary results of a new method. J Trauma; 47(2):372–378. 9. Metaizeau JP (1988) L’Ostéosynthèse chez l’enfant par ECMES. Saurcamps Medical. 10. Prevot J (1989) [Stable elastic nailing.] Z Unfallchir Versicherungsmed Berufskr; 82(4):252–260. 11. Schmittenbecher PP, Dietz HG, Linhart WE, et al (2000) Complications and problems in intramedullary nailing of children’s fractures. European Journal of Trauma; 287–293. 12. Weinberg AM, von Bismarck S, Castellani C, et al (2003) Descending intramedullary nailing for the treatment of displaced supracondylar humeral fractures in children. Chirurg; 74(5):432–436.
Correspondence address: Theddy Slongo, MD Department of Pediatric Surgery University Children’s Hospital 3010 Bern, Switzerland phone: +41 31 632 9293 fax: +41 31 632 9292 email: [email protected]
Complications and failures of the ESIN technique Theddy F. Slongo Department of Pediatric Surgery, Children’s University Hospital, Bern, Switzerland
KEYWORDS: Elastic stable intramedullary nailing; child; rotational failure; corkscrew phenomenon; shortening; biomechanical properties; insertion point; femur fracture, humerus fracture; tibia fracture; forearm fracture.
Summary1 Only knowledge of the possible failures and complications of a method allows its correct application. This also applies to ESIN (Elastic Stable Intramedullary Nailing), which has been promoted as a simple procedure. Most failures occur through neglect of the important biomechanical principles, and by obvious technical errors. The combination of both causes of failure can lead to serious complications in this method, which is generally regarded as “benign”. These complications include serious rotational deformity, leg shortening, and growth disorders from growth plate injuries. A fundamental distinction must be made between intraoperative and postoperative problems and true complications. The present paper is intended to contribute towards avoiding such errors and detecting errors as early as possible during surgery in order to correct them.
Introduction Any method is only as good as its application, applies particularly to Elastic Stable Intramedullary Nailing (ESIN). It is a relatively simple method, but even simple things have to be learned and performed correctly. The simplicity of the method and of the implant can mislead anyone who neglects to study and follow the basic principles of the method, and fails to consider the indications and contraindications [4, 6, 9, 10]. There is no excuse for poorly performed nailing and causing completely avoidable problems [5, 11]. However, analysis of the failures clearly shows that it is not a question of failures due to the implant, but instead ignoring the basic principles of technique. The “benign nature” of ESIN is, however, largely forgiving of incorrect application. Moreover, the corrective potential of the child’s skeleton contributes towards the healing of fractures that have received suboptimal treatment. A follow-up study of all of our femoral fractures treated with
1
Abstracts in German, French, Italian, Spanish, Japanese, and Russian are printed at the end of this supplement.
0020–1383/$ — see front matter ß 2004 Published by Elsevier Ltd. doi:10.1016/j.injury.2004.12.017
ESIN showed that surgeons with little experience of this method showed significantly higher rates of problems and complications. On the other hand, however, long-term analysis showed that practically all these early problems remodelled, and the end results were always good. This should not mislead us into thinking that the method need not be performed correctly, particularly because the indication is being increasingly widened, with unstable fractures being treated with this method [8]. With over 18 years’ continuous experience with this method, including running more than 50 workshops, and collecting comprehensive documentation, this paper discusses the most frequent problems and errors. In so doing, we will specifically address systemrelated and fracture-related problems separately.
Principle failures Biomechanical properties In contrast to solid nails, which are locked by means of screws for axial as well as rotary stability, the same principle is achieved in ESIN through a so-called
Complications and failures of the ESIN techninque
S-A79
Fig. 2: (a) No inner contact to the cortex layer; (b) correct contact to the inner cortex layer.
Fig.1: Schematic representation of the classic 3-point support: The greater and more extended the internal contact, the better the stability.
“3-point support” (Fig. 1). This principle must be strictly adhered to [4, 10]. The greater the instability of the fracture, the more the inner bracing must be increased.
Most errors that are made in relation to biomechanics are based on a lack of internal support. The nails either touch the inner surface of the cortex too little, or not at all, because of insufficient pre-bending of the nails. By pre-bending the nails, this inner contact pressure can be markedly increased, which is more important than the proximal and distal anchor points (Fig. 2). Only through correct tensioning of the nails can the dynamic principle of this method
Fig. 3: Typical example of a combination of errors: nails too thin, several crossovers (corkscrew phenomenon), no inner contact. When first subjected to loading, this led to loss of position, which was repositioned with the nails in place under a general anesthetic, and with a spica cast for 3 weeks.
S-A80
fulfill its potential. This principle is based on the circular muscle mantle and the restoring force of the pre-stressed nails, which repeatedly bring the fragments back into an anatomical position. Care should be taken to ensure that the per-bending of both nails is symmetrical over the same length [8]. In principle, two nails of the same thickness and similarly pre bended should always be used. Nails of differing thicknesses with the same pre-bending have a different “restoring force”, which pushes the proximal fragment into a varus or valgus position. For reasons that are not entirely clear, this basic principle is repeatedly ignored. For the sake of completeness, however, it should be mentioned that this asymmetrical effect is undoubtedly desirable, when the fracture or soft tissues have a tendency to develop varus or valgus.
T.F. Slongo
Nail diameter In general, the nail diameter should be selected to correspond to between one third and 40% of the narrowest medullary space diameter [4, 9, 10]. The sole exception is the forearm, where only one nail is inserted per bone. The thickness should be 60% of the medullary space, since both bones are considered as one. In the upper extremity, nails that are too thin cause minimal problems whereas in the lower extremity unacceptable problems occur, even in transverse fractures [11]. These problems include axial malalignment, which requires correction followed by additional plaster immobilization. Occasionally, replacement of the nails is required (Fig. 3). As already mentioned, differing nail thicknesses also lead to axial deformity, which causes to functional and cosmetic impairment.
Insertion point
Fig. 4: (a) Defective positioning of the insertion points, asymmetrical, leads to unequal tension; (b) correct position.
Incorrect positioning of the nail insertion points can have various negative effects for the [3]: 1. Insertion points that do not lie opposite one another greatly influence the biomechanics (differing internal tension) and thus the stability of the fracture fixation (Fig. 4, 5). One exception is the so-called monolateral treatment (anterograde nailing of the femur or anterograde and retrograde nailing of the humerus), which
Fig. 5: Insertion point too high, and asymmetrical. Besides the inadequate bracing, the high and long lateral nail leads to muscle and skin problems.
Complications and failures of the ESIN techninque
is, however, only used for distal metaphyseal femoral fractures, supracondylar fractures and proximal humeral fractures. 2. In the distal femur in particular, insertion points that are too diaphyseal lead to severe muscle irritation. Moreover, during insertion and more so during removal of the nail, the musculature is further damaged (Fig. 5). 3. Without sufficient preparation, injury to the superficial branch of the radial nerve can occur over the distal radius [11]. In the same way, injuries to the ulnar nerve can occur at the proximal ulnar insertion point. Both these problems can be avoided by selecting—as is currently recommended—a dorsal insertion point on the distal radius, and a radial insertion point on the proximal ulna. 4. One of the errors with the most serious consequences is injury to growth plates due to insertion points that are too close to the epiphysis. Injury to the perichondral ring occurs at the time of formation of the entry point and also the position of the nail after insertion. We know of cases that have led to growth arrest requiring surgical correction (Fig. 6).
Fig. 6: Fittings of this type lead to injury to the perichondral ring and thus to growth disorders.
S-A81
Fig. 7: Nail cut off too long in conjunction with heavy curvature leads to blocking of the knee and to skin irritation, even perforations.
Fig. 8: Multiple turning of the nail leads to the nails twisting, and to loss of inner bracing, the so-called “corkscrew phenomenon”.
S-A82
5. Finally, nails that left too long lead to severe skin irritation and even skin breakdown [11]. In the distal femur, the ileotibial tract can be blocked, thus inhibiting knee flexion (Fig. 7).
“Corkscrew phenomenon” Difficulties with fracture reduction as well as advancing the second nail may tempt the surgeon to rotate the nail more than 180°. This will lead to one nail being wound around the other. This process is called the “corkscrew phenomenon”. This reduces the effective internal tension of the two nails, which then act as a simple central nail, which is neither rotationally nor axially stable. This phenomenon must be detected using the image amplifier and avoided at all costs. Once the phenomenon has been detected, the nail in question must be removed during the same operation and replaced by a correctly placed one (Fig. 8). In the following sections, fracture-specific errors will be described in further detail. The principal problems that have already been mentioned must be borne in mind at all times, and every effort made to avoid them [1, 2, 3, 5].
Fig. 9: A medial nail that is inserted far in a proximal direction can very easily perforate on the calcar if rotation of the tip is ignored. For this reason, good fluoroscopy is an important prerequisite for this method.
T.F. Slongo
Failures femoral nailing The three most common errors are: Perforation of the medial nail through the calcar Due to the procurvatum of the femur, the medial nail continually moves in a dorsal direction towards the calcar. Here, it can easily perforate the thin cortex. Therefore it is essential to monitor nail progression using an image intensifier. If the nail tip is directed dorsally and makes contact with the calcar, the nail must be retracted and rotated 90° in a ventral direction so that it can progress without perforation (Fig. 9). Failure to catch the proximal fragment In long spiral fractures, but also in transverse fractures, the surgeon may not realize that one of the nails has not caught the proximal fragment. This is difficult to detect clinically, since the stability is often initially good, due to the subperiostal position of the nail. This error is mainly due to the poor positioning of fluoroscope, and failures to obtained orthogonal images in two views 90° to each other (Fig. 10).
Fig. 10: Failure to catch the proximal fragment. This error is due to a poor fluoroscopy technique which does not allow fluoroscopy in both planes.
Complications and failures of the ESIN techninque
Inappropriate nail thickness The correct nail thickness (40%) is required for adequate stability and optimum biomechanics. Both nails must have identical thickness and curvature. Any mistake is particularly detrimental for the femur, since a second anesthesia is required either to replace the nails perform further reduction, or apply a spica cast (Fig. 3).
Failures of forearm nailing Incorrect treatment of forearm fractures by means of ESIN has, in principle, similar consequences to those that can be seen with conservative treatment. The greatest problem is malunions which leads to restricted function, particularly pronation and supination. Forearm deformity that does not remodeled can be a cosmetically disfiguring. The causes are first in selection of nails that are too thin (remember they should be 60% of the medullary space), and secondly lack of correct tensioning of the two nails against one another so that the interosseous membrane is tensioned appropriately. However, the greatest problems due the inappropriate use of ESIN methods for radial fractures in the
Fig. 11: Critical indication for the ESIN technique: The distal fragment is too short and is not held adequately by the nail. A malunion arose, which made a correction necessary. A better alternative here is an external fixator.
S-A83
distal third and metaphyseal regions which are not ideal indications for ESIN. In this region, the insertion point must be selected carefully on the dorsal aspect if possible. Furthermore, the nail must be considerably pre-bent near the end, so that it makes contact with the opposite cortex of the distal fragment. This will otherwise tilt the distal fragment in an ulnar direction (Fig. 11). It is generally accepted that one should not undertake removal of the metal before 4–6 months, and the fracture must be completely consolidated. It is unlikely refractures will be occur if this rule is followed. Thus, in contrast to plate osteosynthesis and conservative treatment, the risk of refracture is not due to the method but due to the surgeon who decides to remove the nails early. Anterograde nailing of the radius should be avoided since it can lead to injury of the deep branch of the radial nerve [11].
Failures of humeral nailing Since the decision for osteosynthesis of the humerus should be made cautiously, and problems of function and healing are almost unknown on the humerus,
Fig. 12: Due to the triangular cross-section of the tibia head, the nails follow the dorsal cortex layer. A recurvature arises. By turning the nail tips in a dorsal direction, the tibia can be straightened.
S-A84
T.F. Slongo
technical errors in osteosynthesis hardly ever have long-term effects. Nevertheless, some special features should be noted. In principle, humeral nailing is performed in a retrograde manner, monolaterally from lateral side. It is recommended to expose the distal humerus and to make the entry-points under direct vision. If the entry-points are made too high by closed means, there is a risk of damaging the radial nerve. Ulnar insertion should be avoided, to spare the ulnar nerve. The same risk of nerve damage exists in anterograde nailing for supracondylar humeral fractures [9, 12].
Failures of tibia nailing The treatment of tibial fractures by ESIN represents a great challenge, less so because of problems with reduction and placement of the nails but because of problems with the correct technique, which is always anterograde. The tibia is completely different from other limb segments. There are two reasons for this: First of all, the tibia lies completely eccentric in the musculature, which is of critical importance in ESIN. Secondly, the tibia is triangular in the crosssection, with the base dorsal, and the two sides aligned diagonally. The planes of the nail are thus likewise aligned in the diagonal, with the tension being directed in a dorsal direction. This arrangement
Fig. 13: Insufficient stability and blocking of the nail lead to pseudarthroses of the tibia, even in children.
leads to the situation that in the “normal” position of the nails, recurvatum of the tibia always occurs. This must be counteracted by turning the nail tips in a dorsal direction after definitive placement (Fig. 12). The literature, as well as our own experience, has shown that this segment is associated with the highest rate of problems and complications. The tibia is practically the only bone that develops nonunion or pseudarthrosis. The isolated tibial fracture must be mentioned above all in this context. An isolated tibial fracture is often accompanied by bowing of the fibula Stabilization of tibial fractures by ESIN often leads to slight distraction at the fracture side which blocks complete reduction (Fig. 13). This treatment can almost be regarded as a type of “pseudarthrosis model”. Retrograde nailing should be avoided, as distal insertion points damage the tendons, and use of ESIN methods for proximal tibial fractures is contraindicated. The pull of the patellar ligament is too great for the short segment of nails to hold the proximal fragment. Figure 14 illustrates the indications.
Discussion Only a few publications deal exclusively with the problems and complications of ESIN. Authors usually report only their own good results. In a multicenter
Fig. 14: Indications for ESIN on the tibia: Green is very suitable, orange is suitable to a limited extent, and red is unsuitable.
Complications and failures of the ESIN techninque
retrospective study of pediatric clinics in München, Regensburg, Graz, and Bern, of over 900 fractures treated using ESIN, it was nevertheless possible to demonstrate high rates of problems or complications [11]. In the majority of cases, however, these problems or postoperative complications do not influence the end result, which is very fortunate. This finding was also demonstrated in an as yet unpublished investigation of our own where it was shown that in the long-term only isolated problems such as length differences or axial errors were demonstrated. Just two cases had postoperative problems; the others had new problems that could not easily be attributed to the accident with difficulty. Time after time, analysis and discussion of problem cases show that the problem lies more with the surgeon than with the method. Thus the most frequent errors are made in establishing the appropriate treatment in relation to the biomechanics of the fracture, followed by technical errors such as the nails being too thin, “corkscrew phenomenon”, and lack of 3-point support. It is therefore necessary to continually emphasize that correct application is extremely important, and that the training that is increasingly on offer should be taken up. It is fatal to rely simply on the child’s potential for correction. If one decides on an operation, it should be carried out as carefully and correctly as possible. Only knowledge of all possible problems and complications will enable the surgeon to avoid them. It must, however, be emphasized that it is the ESIN technique that is often forgiving of our technical errors without serious complications for the child, making the method popular for a wide range of applications.
S-A85
References 1. Bettermann A, Kunze K, van Ackeren V (1989) Oberschenkelschafttrakturen im Wachstumsalter—Resultate nach Wachstumsabschluss. Unfallchirurgische Klinik der Universität Giessen. 2. Bowyer G, Clarke N.M.P, Gonzalez P (1995) Complications of pediatric femoral nailing. Bone Joint Surg; 77(4):666–667. 3. Braten M, Terjesen T, Rossvoll I (1993) Torsional deformity after intramedullary nailing of femoral shaft fractures. Measurement of anteversion angles in 110 patients. J Bone Joint Surg Br; 75(5):799–803. 4. Dietz HG, Schmittenbecher PP, Illig Intramedulläre Osteosynthese im Wachstumsalter. Urban & Schwarzenberg. 5. Flynn JM, Hresko T, Reynolds RA, et al (2001) Titanium elastic nails for pediatric femur fractures: a multicenter study of early results with analysis of complications. J Pediatr Orthop; 21(1):4–8. 6. Galpin RD, Willis RB, Sabano N (1994) Intermedullary nailing of pediatric femoral fractures. J Pediatr Orthop; 14(2):184– 189. 7. Heinrich SD, Drvaric D, Darr K et al (1992) Stabilization of pediatric diaphyseal femur fractures with flexible intramedullary nails (a technique paper). J Orthop Trauma; 6(4):452–459. 8. Linhart WE, Roposch A (1999) Elastic stable intramedullary nailing for unstable femural fractures in children: preliminary results of a new method. J Trauma; 47(2):372–378. 9. Metaizeau JP (1988) L’Ostéosynthèse chez l’enfant par ECMES. Saurcamps Medical. 10. Prevot J (1989) [Stable elastic nailing.] Z Unfallchir Versicherungsmed Berufskr; 82(4):252–260. 11. Schmittenbecher PP, Dietz HG, Linhart WE, et al (2000) Complications and problems in intramedullary nailing of children’s fractures. European Journal of Trauma; 287–293. 12. Weinberg AM, von Bismarck S, Castellani C, et al (2003) Descending intramedullary nailing for the treatment of displaced supracondylar humeral fractures in children. Chirurg; 74(5):432–436.
Correspondence address: Theddy Slongo, MD Department of Pediatric Surgery University Children’s Hospital 3010 Bern, Switzerland phone: +41 31 632 9293 fax: +41 31 632 9292 email: [email protected]