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The Management of Flexor Tendon Injuries
The Management of Flexor Tendon Injuries A. R. WAKEFIELD, M.S., F.R.C.S., F.R.A.C.S. Melbourne, Australia
THE cut flexor tendon has always presented a challenge to the surgeon and there are few conditions in surgery where the result is more directly dependent upon a high order of care and precision in technique than in this field. The problem may be presented to us immediately as a complication of a clean, incised wound or as part of an untidy, dirty, mangling type of injury. It may be the only complication or it may be one of several. It may also be presented to us weeks or months after the initial injury, when the opportunity for primary, definitive surgery is long since past. Furthermore, it is a problem which varies in its technical ramifications according to whether one or both of the flexor tendons is severed and according to the situation along the length of the tendon. All these differing circumstances may occur in various combinations, each of which may require a different line of management. FLEXOR TENDON INJURIES IN RECENT CLEAN-CUT WOUNDS
The word "recent" in this connection can be variously interpreted but it has been our experience that definitive surgery can be carried out for this type of injury, in the manner subsequently described, up to 24 hours from the time of injury with safety, provided that (1) there has been no meddlesome interference or exploration of the wound, (2) the wound has been covered immediately with a sterile dressing which has been undisturbed and the limb has been kept immobilized with an adequate splint, and (3) an adequate antibiotic cover has been effected from within a few hours of the injury.
At the Wrist and in the Carpal Tunnel In this situation, the flexor tendons are commonly divided in association with either the median or the ulnar nerve, or both. Primary repair of both the tendons and the nerves is indicated in these cases. It is, however, unnecessary to repair both the sublimis and profundus tendons to each finger. Repair can be confined to the flexor profundus tendons and
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the flexor pollicis longus together with whatever nerves are involved. The cut ends of the sublimis tendons should be excised from the operative field. If we fail to carry out this repair at this opportune stage, muscle and tendon shortening will occur rapidly within the next few weeks and any secondary operation that is proposed will encounter great difficulties, even as early as three or four weeks from the time of injury. Primary direct repair therefore in this situation is a must. In the Palm
In this situation beyond the distal edge of the carpal tunnel and proximal to the commencement of the flexor tendon sheath in the region of the distal palmar skin crease, the same principle of primary direct repair holds good. Here again, it is necessary, in fact desirable, to repair only the profundus tendon where both are severed. Repair of both tendons may be followed by cross-union and limitation of the function of each. Although the lumbrical attachment of the proximal end of the cut profundus tendon prevents its retraction for more than a short distance, and therefore delayed repair is more easily effected than at the wrist, nevertheless secondary repair is always more difficult and may become impossible after a long delay. Here, too, primary direct repair is a must. Within the Digital Theca as Far as the Insertion of the Flexor Sublimis into the Middle Phalanx
Direct repair of flexor tendons within this area has always been a relatively unsuccessful operative. procedure. Some surgeons are still endeavoring to perfect a technique which will permit this to be done more successfully, but although the prospects seem to offer some promise, the method is nevertheless not of general application. Under most circumstances, attempts at direct repair in this region will not only fail but will render the finger unsatisfactory for any other form of tendon repair or replacement. For this reason, it must be condemned as a general practice. The alternative of flexor tendon grafting in this situation has become widely accepted and will certainly, in most surgeon's hands, give vastly superior results to any attempt at direct repair. It is generally agreed that the reasons for failure of direct repair are associated with adhesion to the closely related rigid surrounding structures, such as the tendon sheath itself and the phalanges and joints posteriorly. Although the anterior portion of the sheath can be removed in the region of the suture line to bring the area of repair into contact with more mobile fat, this is of limited value and, of course, the posterior wall cannot be dealt with in similar fashion. The objective of the tendon grafting procedure is to have no suture points in the tendon, as it passes through this area of digital theca. The only points where the tendon is sutured are placed well proximally in the
The Management of Flexor Tendon Injuries
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mobile area of the palm and well distally beyond the last joint affected by the tendon's action. The greater part of the anterior wall of the digital theca is removed leaving only narrow bands to act as pulleys for the tendon graft. Much discussion has occurred on the subject of whether the tendon graft which is used should retain as much of its original paratenon as possible. Many earlier writers felt that this paratenon was of extreme importance in the success of the graft. More recently, however, doubt has been thrown upon this, and it appears that tendon grafts can certainly be equally successful, if not more so, without paratenon provided their visceral layer of synovium is undamaged. The palmaris longus, where present, remains the most ready and effective source of grafting material. I t has been generally the practice to confine the initial surgery in these cases to wound toilet and careful skin closure, and to leave the operation of tendon grafting until a few weeks later. This, however, is by no means obligatory. Under good conditions within a few hours of the injury and with experienced surgical attention available, there is no reason at all why the tendon graft should not be carried out forthwith. There are, indeed, certain important advantages in so doing in selected cases. For example, the length of the tendon graft to be used is very easily determined because there has been no tendon contraction or shortening. The graft can be measured exactly against the length of the damaged tendon removed. Primary tendon grafting also overcomes the disadvantage, which is often seen, of having to do secondary operations through an indurated, edematous, scarred area a few weeks later. If one is to wait for this to resolve, it is often nearer three months than the three or four weeks which are often quoted. It should be emphasized, however, that the execution of this policy is entirely dependent upon the essential conditions and services being available. All that I have said in relation to flexor tendon injuries in this situation must be applied only to adults and to children over the age of about four years. Younger than this, primary direct repair in the region is a very successful procedure, and certainly a great deal simpler in a tiny child than tendon grafting. There is no justification at all for not carrying out a primary direct repair in a small child. They do very well and even in the few that may fail, a tendon graft is always possible at a later date. It is difficult to say just what is the age at which this alteration in prognosis of direct repair occurs, but it would extend over the period of four to six years of age. Although occasional successes from direct repair may be obtained later than this, they are probably not sufficiently frequent to justify the method, and tendon grafts, as for adults, will be better. In this region it is usual for both tendons to be cut. However, if the profundus alone is cut and there is a strong sublimis action still present, the tendon graft can be inserted through the sublimis bifurcation, leaving
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the sublimis tendon intact if it has been undamaged. Under these circumstances the tendon graft should certainly be done primarily if the opportunity exists, for the sublimis tunnel rapidly closes down in the succeeding weeks, and a secondary operation of this nature may not be possible without prejudice to the sublimis action. If the sublimis alone is severed, the situation probably will not be recognized. Even if it is, no direct action is necessary. These comments all refer to the flexor tendons in the fingers. In the thumb, however, there being only one tendon and with one less joint involved, the situation is entirely different. Here the results of carefully conducted primary direct repair are excellent. There is no reason at all in the thumb for adopting a policy of tendon grafting as a first choice. Distal to the Sublimis Insertion
In this region over the middle phalanx and near the insertion of the profundus tendon, the profundus is frequently divided, leaving the sublimis intact and fully functioning. Again, the principle of primary direct repair should be adopted. The results of this procedure are good in most cases and, even if not fully effective, at least the end joint is stabilized. FLEXOR TENDON INJURY RECOGNIZED TOO LATE FOR PRIMARY DEFINITIVE SURGERY
If the injury is recognized early and if the wounds heal quickly without sepsis then the same lines of treatment as set out for recent injuries can be carried out as early secondary procedures within three weeks of the injury in most cases. Later than this however, problems of tendon shortening and contracture, closure of fascial tunnels and tendon sheaths alter the picture considerably. At the wrist and even in the palm it may no longer be possible to carry out a direct repair and in this case either free tendon grafts to bridge the gaps or tendon transfers using motor units from other fingers may be necessary. These of course will only be effective if the flexor tendons still lie free and mobile within the digital theca. If, with lapse of time and inactivity, they have become adherent along the whole of this length, then complete replacement from wrist to fingertip with tendon grafts may, on occasions, be necessary. Fortunately, this is not common. Where the injury is confined to the tendons to a single finger and a long period has elapsed, with shortening, the use of an adjacent sublimis tendon as a motor unit will be preferable, but where many tendons to several fingers are divided, as occurs frequently at the wrist, then free grafts may be essential. Within the digital theca where free tendon grafts are the method of choice in any patients except small children, the lapse of time will not necessarily be a disadvantage and the tendon graft can be carried out successfully months or even years after the injury.
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In the case of the thumb, if more than three or four weeks have passed since the injury, a free tendon graft will usually be desirable rather than direct suture under tension. It is in the case of the severed profundus alone, distal to the sublimis insertion, that the consequences of not repairing the severed tendon primarily are seen at their worst. Up to about three weeks direct repair may still be carried out with success, but later than this tendon retraction and shortening make direct repair impossible. Under these circumstances, with an intact and functioning sublimis, a decision will have to be made between three possible lines of approach: (1) If the sublimis is not damaged and its tunnel has not closed down, a free graft may be inserted leaving the sublimis intact with good prospects of success. This needs to be done very gently and carefully, and there would be no justification at all for the procedure if the sublimis action were prejudiced in any manner. (2) If the sublimis tunnel is closed and there is scarring in the region, it is usually not possible to carry out a free graft without prejudice to the sublimis action, and the end joint can be rendered stable in slight flexion by the operations of tenodesis, fixing the distal stump of the profundus to the middle phalanx to stabilize the end joint. This fixation can be reinforced by the insertion of a small Kirschner wire across the terminal interphalangeal joint as a temporary measure. (3) An alternative method of stabilizing the end joint under these circumstances is a simple arthrodesis of the joint in slight flexion. The decision as to which of these three alternatives to adopt is often a difficult one, and cannot be made until the finger is opened and the state of affairs determined at exploration. FLEXOR TENDON INJURY IN UNTIDY WOUNDS
The term "untidy" refers to those wounds of a mangling, crushing or tissue damaging nature, which involve much more than simple clean-cut wounds. They are inflicted by machines and by crushing, bursting injuries and are often associated not only with damaged tendons but with areas of skin loss or doubtful viability, nerve damage and multiple fractures. There may also be actual loss or extensive damage along the length of the tendons involved. Frequently they are associated, too, with ingrained dirt, grease and other contaminating agents to an extensive degree. In the great majority of such cases no thought should be given to any definitive repair of tendons or nerves at the stage of primary surgery. The objective of the initial operation is to ensure fixation of fractures in an optimum position and an intact surface over viable tissue. If this objective of early union of fractures and early surface healing is achieved in the shortest possible time, then the earliest possible secondary nerve and tendon repair will be able to be carried out, possibly within a few weeks. Under these circumstances, the various methods of secondary tendon repair as previously described can be used with not much delay
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beyond that which sometimes occurs in relation to clean-cut wounds. Free tendon grafts and tendon transplants will usually be necessary and will often be combined with nerve repairs. Many such cases, however, will need to go through a phase of secondary management directed to the restoration of joint function prior to any direct attack on the tendon problem. It can be said that the expectation of active movement following a tendon repair of any type can only be in terms of what passive range existed preoperatively in the involved joints. This means that secondary intervention may need to be delayed for many months on occasions. In fact, there are times when the injury has been so severe that the passive joint range is never recovered and, therefore, tendon repair never becomes a practical proposition. In most cases, however, where the initial objective of early healing has been achieved the tendons can be dealt with secondarily within a few months. Despite these generalizations, there are, however, some cases which fall somewhere in between the simple skin cut and the gross mangling type of injury. Such injuries, for example, are the axe cut, which may damage skin, tendons, nerves, bones and joints quite extensively without any loss of tissue and where the end result of primary repair of all these structures including internal fracture fixation may be greatly superior to the results of secondary repair of each or all of them at a later date. Similarly, in some power saw injuries, where the saw blade is fine and the injury, though extensive, does not involve a lot of death of tissue over a large area, the results of direct repair despite perhaps some increase in risk of sepsis may be greatly superior to those of delayed secondary management. The transverse saw cut in the palm of this nature, which cuts through all tendons and nerves to all fingers may well be best treated by primary repair of all these structures, with its limitations, than by delayed secondary tendon grafts and possibly nerve grafts, too, to all fingers. Considerable judgment is required in selecting such cases and the risks of sepsis in relation to the anticipated end result must be weighed very carefully. It is sufficient to say that not all cases are easily subdivided into one or other of the major groups. There will be some in which, despite extensive injury, primary repair is still a practical method and one which may pay dividends. Throughout this and indeed all types of reparative surgery, the influence of the patient's age in relation to the prognosis and in relation to the selection of surgical procedure must never be forgotten. The small child is a wonderful subject for all reparative surgery and in him there are very few hand injuries, whatever their severity, that do not lend themselves to primary repair of the damaged structures. Indeed, this should be the aim and objective of primary surgery in small children. Secondary surgery, on the other hand, may be tedious and the dissection of the tiny structures involved and their replacement by grafts may be very difficult, indeed. Certainly, secondary surgery is a poor second best in small children.
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On the other hand, in elderly people, where the results of flexor tendon surgery even at its best are not necessarily very good, in the more severe injuries it may be best to concentrate on the simplest possible type of repair commensurate with reasonable function. In such people the niceties of many of the technical exercises involved in elaborate repairs and grafts are not rewarded by commensurate results and the simplest way out is often the best. Stabilizing procedures will often be better than operations designed to restore flexor tendon function in the elderly age group. Notwithstanding these limitations, however, the surgery of flexor tendon repair at all levels and under all circumstances has advanced greatly in the last generation. A great deal of work continues to be done on all aspects of this subject and there is little doubt that further improvements in methods and in prognosis will follow. 29 Royal Parade Parkville N2 Melbourne, Australia
THE cut flexor tendon has always presented a challenge to the surgeon and there are few conditions in surgery where the result is more directly dependent upon a high order of care and precision in technique than in this field. The problem may be presented to us immediately as a complication of a clean, incised wound or as part of an untidy, dirty, mangling type of injury. It may be the only complication or it may be one of several. It may also be presented to us weeks or months after the initial injury, when the opportunity for primary, definitive surgery is long since past. Furthermore, it is a problem which varies in its technical ramifications according to whether one or both of the flexor tendons is severed and according to the situation along the length of the tendon. All these differing circumstances may occur in various combinations, each of which may require a different line of management. FLEXOR TENDON INJURIES IN RECENT CLEAN-CUT WOUNDS
The word "recent" in this connection can be variously interpreted but it has been our experience that definitive surgery can be carried out for this type of injury, in the manner subsequently described, up to 24 hours from the time of injury with safety, provided that (1) there has been no meddlesome interference or exploration of the wound, (2) the wound has been covered immediately with a sterile dressing which has been undisturbed and the limb has been kept immobilized with an adequate splint, and (3) an adequate antibiotic cover has been effected from within a few hours of the injury.
At the Wrist and in the Carpal Tunnel In this situation, the flexor tendons are commonly divided in association with either the median or the ulnar nerve, or both. Primary repair of both the tendons and the nerves is indicated in these cases. It is, however, unnecessary to repair both the sublimis and profundus tendons to each finger. Repair can be confined to the flexor profundus tendons and
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the flexor pollicis longus together with whatever nerves are involved. The cut ends of the sublimis tendons should be excised from the operative field. If we fail to carry out this repair at this opportune stage, muscle and tendon shortening will occur rapidly within the next few weeks and any secondary operation that is proposed will encounter great difficulties, even as early as three or four weeks from the time of injury. Primary direct repair therefore in this situation is a must. In the Palm
In this situation beyond the distal edge of the carpal tunnel and proximal to the commencement of the flexor tendon sheath in the region of the distal palmar skin crease, the same principle of primary direct repair holds good. Here again, it is necessary, in fact desirable, to repair only the profundus tendon where both are severed. Repair of both tendons may be followed by cross-union and limitation of the function of each. Although the lumbrical attachment of the proximal end of the cut profundus tendon prevents its retraction for more than a short distance, and therefore delayed repair is more easily effected than at the wrist, nevertheless secondary repair is always more difficult and may become impossible after a long delay. Here, too, primary direct repair is a must. Within the Digital Theca as Far as the Insertion of the Flexor Sublimis into the Middle Phalanx
Direct repair of flexor tendons within this area has always been a relatively unsuccessful operative. procedure. Some surgeons are still endeavoring to perfect a technique which will permit this to be done more successfully, but although the prospects seem to offer some promise, the method is nevertheless not of general application. Under most circumstances, attempts at direct repair in this region will not only fail but will render the finger unsatisfactory for any other form of tendon repair or replacement. For this reason, it must be condemned as a general practice. The alternative of flexor tendon grafting in this situation has become widely accepted and will certainly, in most surgeon's hands, give vastly superior results to any attempt at direct repair. It is generally agreed that the reasons for failure of direct repair are associated with adhesion to the closely related rigid surrounding structures, such as the tendon sheath itself and the phalanges and joints posteriorly. Although the anterior portion of the sheath can be removed in the region of the suture line to bring the area of repair into contact with more mobile fat, this is of limited value and, of course, the posterior wall cannot be dealt with in similar fashion. The objective of the tendon grafting procedure is to have no suture points in the tendon, as it passes through this area of digital theca. The only points where the tendon is sutured are placed well proximally in the
The Management of Flexor Tendon Injuries
269
mobile area of the palm and well distally beyond the last joint affected by the tendon's action. The greater part of the anterior wall of the digital theca is removed leaving only narrow bands to act as pulleys for the tendon graft. Much discussion has occurred on the subject of whether the tendon graft which is used should retain as much of its original paratenon as possible. Many earlier writers felt that this paratenon was of extreme importance in the success of the graft. More recently, however, doubt has been thrown upon this, and it appears that tendon grafts can certainly be equally successful, if not more so, without paratenon provided their visceral layer of synovium is undamaged. The palmaris longus, where present, remains the most ready and effective source of grafting material. I t has been generally the practice to confine the initial surgery in these cases to wound toilet and careful skin closure, and to leave the operation of tendon grafting until a few weeks later. This, however, is by no means obligatory. Under good conditions within a few hours of the injury and with experienced surgical attention available, there is no reason at all why the tendon graft should not be carried out forthwith. There are, indeed, certain important advantages in so doing in selected cases. For example, the length of the tendon graft to be used is very easily determined because there has been no tendon contraction or shortening. The graft can be measured exactly against the length of the damaged tendon removed. Primary tendon grafting also overcomes the disadvantage, which is often seen, of having to do secondary operations through an indurated, edematous, scarred area a few weeks later. If one is to wait for this to resolve, it is often nearer three months than the three or four weeks which are often quoted. It should be emphasized, however, that the execution of this policy is entirely dependent upon the essential conditions and services being available. All that I have said in relation to flexor tendon injuries in this situation must be applied only to adults and to children over the age of about four years. Younger than this, primary direct repair in the region is a very successful procedure, and certainly a great deal simpler in a tiny child than tendon grafting. There is no justification at all for not carrying out a primary direct repair in a small child. They do very well and even in the few that may fail, a tendon graft is always possible at a later date. It is difficult to say just what is the age at which this alteration in prognosis of direct repair occurs, but it would extend over the period of four to six years of age. Although occasional successes from direct repair may be obtained later than this, they are probably not sufficiently frequent to justify the method, and tendon grafts, as for adults, will be better. In this region it is usual for both tendons to be cut. However, if the profundus alone is cut and there is a strong sublimis action still present, the tendon graft can be inserted through the sublimis bifurcation, leaving
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the sublimis tendon intact if it has been undamaged. Under these circumstances the tendon graft should certainly be done primarily if the opportunity exists, for the sublimis tunnel rapidly closes down in the succeeding weeks, and a secondary operation of this nature may not be possible without prejudice to the sublimis action. If the sublimis alone is severed, the situation probably will not be recognized. Even if it is, no direct action is necessary. These comments all refer to the flexor tendons in the fingers. In the thumb, however, there being only one tendon and with one less joint involved, the situation is entirely different. Here the results of carefully conducted primary direct repair are excellent. There is no reason at all in the thumb for adopting a policy of tendon grafting as a first choice. Distal to the Sublimis Insertion
In this region over the middle phalanx and near the insertion of the profundus tendon, the profundus is frequently divided, leaving the sublimis intact and fully functioning. Again, the principle of primary direct repair should be adopted. The results of this procedure are good in most cases and, even if not fully effective, at least the end joint is stabilized. FLEXOR TENDON INJURY RECOGNIZED TOO LATE FOR PRIMARY DEFINITIVE SURGERY
If the injury is recognized early and if the wounds heal quickly without sepsis then the same lines of treatment as set out for recent injuries can be carried out as early secondary procedures within three weeks of the injury in most cases. Later than this however, problems of tendon shortening and contracture, closure of fascial tunnels and tendon sheaths alter the picture considerably. At the wrist and even in the palm it may no longer be possible to carry out a direct repair and in this case either free tendon grafts to bridge the gaps or tendon transfers using motor units from other fingers may be necessary. These of course will only be effective if the flexor tendons still lie free and mobile within the digital theca. If, with lapse of time and inactivity, they have become adherent along the whole of this length, then complete replacement from wrist to fingertip with tendon grafts may, on occasions, be necessary. Fortunately, this is not common. Where the injury is confined to the tendons to a single finger and a long period has elapsed, with shortening, the use of an adjacent sublimis tendon as a motor unit will be preferable, but where many tendons to several fingers are divided, as occurs frequently at the wrist, then free grafts may be essential. Within the digital theca where free tendon grafts are the method of choice in any patients except small children, the lapse of time will not necessarily be a disadvantage and the tendon graft can be carried out successfully months or even years after the injury.
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271
In the case of the thumb, if more than three or four weeks have passed since the injury, a free tendon graft will usually be desirable rather than direct suture under tension. It is in the case of the severed profundus alone, distal to the sublimis insertion, that the consequences of not repairing the severed tendon primarily are seen at their worst. Up to about three weeks direct repair may still be carried out with success, but later than this tendon retraction and shortening make direct repair impossible. Under these circumstances, with an intact and functioning sublimis, a decision will have to be made between three possible lines of approach: (1) If the sublimis is not damaged and its tunnel has not closed down, a free graft may be inserted leaving the sublimis intact with good prospects of success. This needs to be done very gently and carefully, and there would be no justification at all for the procedure if the sublimis action were prejudiced in any manner. (2) If the sublimis tunnel is closed and there is scarring in the region, it is usually not possible to carry out a free graft without prejudice to the sublimis action, and the end joint can be rendered stable in slight flexion by the operations of tenodesis, fixing the distal stump of the profundus to the middle phalanx to stabilize the end joint. This fixation can be reinforced by the insertion of a small Kirschner wire across the terminal interphalangeal joint as a temporary measure. (3) An alternative method of stabilizing the end joint under these circumstances is a simple arthrodesis of the joint in slight flexion. The decision as to which of these three alternatives to adopt is often a difficult one, and cannot be made until the finger is opened and the state of affairs determined at exploration. FLEXOR TENDON INJURY IN UNTIDY WOUNDS
The term "untidy" refers to those wounds of a mangling, crushing or tissue damaging nature, which involve much more than simple clean-cut wounds. They are inflicted by machines and by crushing, bursting injuries and are often associated not only with damaged tendons but with areas of skin loss or doubtful viability, nerve damage and multiple fractures. There may also be actual loss or extensive damage along the length of the tendons involved. Frequently they are associated, too, with ingrained dirt, grease and other contaminating agents to an extensive degree. In the great majority of such cases no thought should be given to any definitive repair of tendons or nerves at the stage of primary surgery. The objective of the initial operation is to ensure fixation of fractures in an optimum position and an intact surface over viable tissue. If this objective of early union of fractures and early surface healing is achieved in the shortest possible time, then the earliest possible secondary nerve and tendon repair will be able to be carried out, possibly within a few weeks. Under these circumstances, the various methods of secondary tendon repair as previously described can be used with not much delay
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beyond that which sometimes occurs in relation to clean-cut wounds. Free tendon grafts and tendon transplants will usually be necessary and will often be combined with nerve repairs. Many such cases, however, will need to go through a phase of secondary management directed to the restoration of joint function prior to any direct attack on the tendon problem. It can be said that the expectation of active movement following a tendon repair of any type can only be in terms of what passive range existed preoperatively in the involved joints. This means that secondary intervention may need to be delayed for many months on occasions. In fact, there are times when the injury has been so severe that the passive joint range is never recovered and, therefore, tendon repair never becomes a practical proposition. In most cases, however, where the initial objective of early healing has been achieved the tendons can be dealt with secondarily within a few months. Despite these generalizations, there are, however, some cases which fall somewhere in between the simple skin cut and the gross mangling type of injury. Such injuries, for example, are the axe cut, which may damage skin, tendons, nerves, bones and joints quite extensively without any loss of tissue and where the end result of primary repair of all these structures including internal fracture fixation may be greatly superior to the results of secondary repair of each or all of them at a later date. Similarly, in some power saw injuries, where the saw blade is fine and the injury, though extensive, does not involve a lot of death of tissue over a large area, the results of direct repair despite perhaps some increase in risk of sepsis may be greatly superior to those of delayed secondary management. The transverse saw cut in the palm of this nature, which cuts through all tendons and nerves to all fingers may well be best treated by primary repair of all these structures, with its limitations, than by delayed secondary tendon grafts and possibly nerve grafts, too, to all fingers. Considerable judgment is required in selecting such cases and the risks of sepsis in relation to the anticipated end result must be weighed very carefully. It is sufficient to say that not all cases are easily subdivided into one or other of the major groups. There will be some in which, despite extensive injury, primary repair is still a practical method and one which may pay dividends. Throughout this and indeed all types of reparative surgery, the influence of the patient's age in relation to the prognosis and in relation to the selection of surgical procedure must never be forgotten. The small child is a wonderful subject for all reparative surgery and in him there are very few hand injuries, whatever their severity, that do not lend themselves to primary repair of the damaged structures. Indeed, this should be the aim and objective of primary surgery in small children. Secondary surgery, on the other hand, may be tedious and the dissection of the tiny structures involved and their replacement by grafts may be very difficult, indeed. Certainly, secondary surgery is a poor second best in small children.
The Management of Flexor Tendon Injuries
273
On the other hand, in elderly people, where the results of flexor tendon surgery even at its best are not necessarily very good, in the more severe injuries it may be best to concentrate on the simplest possible type of repair commensurate with reasonable function. In such people the niceties of many of the technical exercises involved in elaborate repairs and grafts are not rewarded by commensurate results and the simplest way out is often the best. Stabilizing procedures will often be better than operations designed to restore flexor tendon function in the elderly age group. Notwithstanding these limitations, however, the surgery of flexor tendon repair at all levels and under all circumstances has advanced greatly in the last generation. A great deal of work continues to be done on all aspects of this subject and there is little doubt that further improvements in methods and in prognosis will follow. 29 Royal Parade Parkville N2 Melbourne, Australia