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Observations on the use of silicone rubber spacers in tendon graft surgery
Observations on the Use o/Silicone Rubber Spacers in Tendon Gra/t Surgery-A. G. Leonard and W. R. Dickie
OBSERVATIONS O N THE USE OF SILICONE R U B B E R SPACERS IN T E N D O N G R A F T S U R G E R Y A. G. L E O N A R D and W. R. DICKIE, Belfast SUMMARY Lesso,ns learned from the use of silicone rubber spacers for the preparation of tendon graft beds in sixty digits are reported. INTRODUCTION The use of silicone rubber spacers prior to flexor tendon grafting is now well established and extensive reviews have been published (Nicolle, 1969; Hunter, 1971; v a n der Meulen, 1971; Helal, 1973). In this Unit silicone rubber rods have been used in a total of sixty digits in forty-nine patients. In reviewing this series of cases several points came to light which do not appear to have been mentioned elsewhere: The purpose of this paper i s to discuss these, and indicate how they have modified our management regime. The indications for the two-stage procedure have been broadly those employed by Helal (Helal, 1973), but even with careful pre-operative assessment, in a relatively large number of cases an unexpected degree of scarring was found at exploration. In these circumstances the preliminary use of a rod was considered advisable, whereas in the past an immediate tendon graft would have been carried out, in a situation likely to be inimical to a good result. It is now our policy to warn patients of the possibility of a two-stage procedure preoperatively, even when this seems unlikely. OPERATIVE TECHNIQUE A laterally-placed digital incision is the generally recommended approach, to minimise the risk of exposure of the rod should wound dehiscence occur. In this series, apart from one digit, the Bruner volar zig-zag approach has been routinely used and has been trouble-free. Care has been taken to ensure that the ends of the rod were placed well away from the incision; the proximal end underlying the profundus tendon in the palm, the distal lying either under the profundus stump or in a pocket in the fingerpulp. The one digit which was an exception h a d been explored elsewhere via a longitudinal volar incision which was closed with a Z-plasty, at insertion of the spacer. Part of the Z-plasty suture line gave way exposing the rod but there was no infection and the wound closed with the rod still in situ. A successful tendon graft was subsequently carried out. It is felt that with careful positioning of the ends of the rod and meticulous attention to haemostasis (Colville, 1971) there is no reason why major breakdown with loss of rod should occur. The value of the volar zig-zag approach is such that in our opinion it should be extended routinely to two-stage procedures. In all cases the spacer used has been a plain silicone rubber rod with no core. In no case has a rod been used as an active functional tendon. In thirteen cases the rod was simply laid in position with no anchoring sutures, and in one of these, at the second stage exploration it was found lying in the forearm. In subsequent cases it was anchored either at the distal end, or at both ends. Where Leonard, A. G., F.R.C.S., The Ulster Hospital, Dundonald, Belfast, BT16 0RH. 66
The H a n d - - V o l . 8
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1976
Observations on the Use o[ Silicone Rubber Spacers in Tendon Graft Surgery-A. G. Leonard and W. R. Dickie
the rod has been anchored at both ends the proximal suture has invariably cut out, so it is now our practice' to anchor the distal end only. At the second stage procedure either a palmaris longus, or an extensor digitorum longus graft, is rail-roaded along the tunnel, in some cases to a calculated length (Colville, 1969) and in others using t h e criteria of tension and finger position: ,,< ,~,
T I M I N G OF THE SECOND S T A G E
The interval between insertion of the rod and its replacement with a formal tendon graft has varied between six-and-a-half weeks and forty-three weeks, with a mean of fifteen weeks. The most frequent reason for a long delay was initial failure to regain an adequate passive range. I n six cases there was an inordinate delay; in one there was great difficulty in regaining the passive range, one was at the patient's request, and four were recalcitrant about attending the follow-up clinic. The most important observation as regards timing is that the thickness of pseudosheath formation is not time dependent. Indeed some of the very late cases had thin sheaths, but in one case in which the second stage was carried out as early as six-and-a-half weeks, the sheath was found to be three millimetres in thickness. In this case biopsy showed the features normally associated with the new capsule, but gave no clue to its exuberance. In a further case with very thick sheath formation there was early progressive contracture of the finger necessitating its eventual amputation. PERIOD OF IMMOBILISATION
An impression has been formed that the initial return of movement following the two-stage procedure is often more rapid than following a conventional tendon graft (Geldmacher, 1969; Van der Meulen, 1971). Experience with two patients suggested that this could be hazardous and they are described in detail. It is suggested that too enthusiastic exercise in the early stages may cause too rapid a return of excursion, with rupture of the secondary vinculae, leading to ischaemic softening, graft rupture, and fibrosis as described below. While no statistical significance can be ascribed to these results, it is now our policy to immobilise for four weeks following the second stage and to allow only the gentlest active exercise during the first week of mobilisation. Case N o . 1. S.P., an eighteen-year-old shipwright, sustained glass lacerations of
the left hand with multiple tendon and nerve injuries. Silicone r u b b e r rods were inserted in the index and middle fingers are replaced with toe extensor grafts nine weeks later. He made good initial progress, but during the period of exercise he "felt something give way" in the middle finger, with a decrease in the range of movement, and subsequently failed to achieve any further improvement. Three months after the original graft the middle finger was re-explored. The graft was adherent throughout its length and a portion of the centre appeared to be attentuated and replaced by scar tissue. The graft was excised and replaced by a rod and subsequent tendon grafting gave a satisfactory outcome: He is now serving in the army. Case N o . 2. G.W., a thirty-two-year-old mechanic, sustained a ragged laceration
of his right hand, which became infected despite debridement and antibiotic cover. When healing was complete and the passive range regained, a silicone rubber rod was inserted in the ring finger. Eight weeks later this was replaced by The Hand--Vol. 8
No. 1
1976
67
Observations on the Use of Silicone Rubber Spacers in Tendon Graft S u r g e r y - A. G. Leonard and W. R. Dickie
a palmaris longus graft. During the sixth post-operative week the graft was felt to give way over the metacarpophalangeal joint, under an examining finger. H e failed to regain any further m o v e m e n t and at re-exploration the same picture of central necrosis and subsequent fibrosis of the graft was found. H e too has had both stages repeated and at four months after his second tendon graft was noted to have a flexion gap (nail to distal interphalangeal joint crease) of only 2 cms., with an extension lag of 45 ° at the distal interphalangeal joint. In the above two cases a good result has been achieved despite an initial poor result, by re-exploration and repetition of both stages of the procedure. This possibility has been suggested (Hunter, 1971) but has not to our knowledge been reported elsewhere. It is suggested that the nature of the initial injury and the age, occupation and motivation of the patient are factors which should be taken into account in a decision as to whether to e m b a r k on surgery of this nature. When these factors are favourable it would seem that a repetition of the two-stage procedure does not reduce the likelihood of a successful result. CONCLUSIONS
The salient points arising f r o m a review of this series of tendon grafts Secondary to silicone rubber rod insertion have been discussed. Excessive scarring was the most frequent indication for the procedure. The Bruner type of incision was used for approach, without complications. There was a wide variation in timing of the second stage and thickness of pseudosheath formation did not seem to be time dependent. It was found necessary to immobilise in flexion for longer than in the one-stage procedure. In two cases of graft rupture in the early stages of mobilisation, a good result was achieved after repetition of both stages, which procedure has not been reported elsewhere. ACKNOWLEDGEMENTS
We wish to record our gratitude to Mr. J. Colville, F.R.C.S., for allowing his cases to be included in this review, and to Miss L. McVea for her assistance in preparation of the manuscript. REFERENCES
BRUNER, J. M. (1973) Surgical Exposure Of Flexor Tendons In The Hand. Annals of the Royal College of Surgeons of England, 53: 84--94. COLVILLE, J. and DICKIE, W. R. (1969) Tendon Graft Length. British Journal of Plastic Surgery, 22: 37-40. COLVILLE, J. (1971) Haemostasis in Hand Surgery. Transactions of Fifth International Congress of Plastic and Reconstructive Surgery, Butterworths, Australia: 522-524. GELDMACHER, J. (1969) Die zweizeitige freie Beugesehnen transplantation Handchirurgie 1: 3, 109-120. HELAL, B. (1973) The Use Of Silicone Rubber Spacers In Flexor Tendon Surgery. The Hand, 5: 85-90. HUNTER, J. M. and SALISBURY, R. E. (1971) Flexor-Tendon Reconstruction in Severely Damaged Hands. A Two-Stage Procedure Using a Silicone-Dacron Reinforced Gliding Prosthesis Prior to Tendon Grafting. Journal of Bone and Joint Surgery, 53a: 829-858. NICOLLE, F. V. (1969) A Silastic Tendon Prosthesis As An Adjunct To Flexor Tendon Grafting: An Experimental And Clinical Evaluation. British Journal of Plastic Surgery, 22: 224-236. VAN DER MEULEN, J. C. (1971) Silastic Spacers In Tendon Grafting. British Journal of Plastic Surgery, 24: 166-173. 68
The HandmVol. 8
No. 1
1976
OBSERVATIONS O N THE USE OF SILICONE R U B B E R SPACERS IN T E N D O N G R A F T S U R G E R Y A. G. L E O N A R D and W. R. DICKIE, Belfast SUMMARY Lesso,ns learned from the use of silicone rubber spacers for the preparation of tendon graft beds in sixty digits are reported. INTRODUCTION The use of silicone rubber spacers prior to flexor tendon grafting is now well established and extensive reviews have been published (Nicolle, 1969; Hunter, 1971; v a n der Meulen, 1971; Helal, 1973). In this Unit silicone rubber rods have been used in a total of sixty digits in forty-nine patients. In reviewing this series of cases several points came to light which do not appear to have been mentioned elsewhere: The purpose of this paper i s to discuss these, and indicate how they have modified our management regime. The indications for the two-stage procedure have been broadly those employed by Helal (Helal, 1973), but even with careful pre-operative assessment, in a relatively large number of cases an unexpected degree of scarring was found at exploration. In these circumstances the preliminary use of a rod was considered advisable, whereas in the past an immediate tendon graft would have been carried out, in a situation likely to be inimical to a good result. It is now our policy to warn patients of the possibility of a two-stage procedure preoperatively, even when this seems unlikely. OPERATIVE TECHNIQUE A laterally-placed digital incision is the generally recommended approach, to minimise the risk of exposure of the rod should wound dehiscence occur. In this series, apart from one digit, the Bruner volar zig-zag approach has been routinely used and has been trouble-free. Care has been taken to ensure that the ends of the rod were placed well away from the incision; the proximal end underlying the profundus tendon in the palm, the distal lying either under the profundus stump or in a pocket in the fingerpulp. The one digit which was an exception h a d been explored elsewhere via a longitudinal volar incision which was closed with a Z-plasty, at insertion of the spacer. Part of the Z-plasty suture line gave way exposing the rod but there was no infection and the wound closed with the rod still in situ. A successful tendon graft was subsequently carried out. It is felt that with careful positioning of the ends of the rod and meticulous attention to haemostasis (Colville, 1971) there is no reason why major breakdown with loss of rod should occur. The value of the volar zig-zag approach is such that in our opinion it should be extended routinely to two-stage procedures. In all cases the spacer used has been a plain silicone rubber rod with no core. In no case has a rod been used as an active functional tendon. In thirteen cases the rod was simply laid in position with no anchoring sutures, and in one of these, at the second stage exploration it was found lying in the forearm. In subsequent cases it was anchored either at the distal end, or at both ends. Where Leonard, A. G., F.R.C.S., The Ulster Hospital, Dundonald, Belfast, BT16 0RH. 66
The H a n d - - V o l . 8
No. 1
1976
Observations on the Use o[ Silicone Rubber Spacers in Tendon Graft Surgery-A. G. Leonard and W. R. Dickie
the rod has been anchored at both ends the proximal suture has invariably cut out, so it is now our practice' to anchor the distal end only. At the second stage procedure either a palmaris longus, or an extensor digitorum longus graft, is rail-roaded along the tunnel, in some cases to a calculated length (Colville, 1969) and in others using t h e criteria of tension and finger position: ,,< ,~,
T I M I N G OF THE SECOND S T A G E
The interval between insertion of the rod and its replacement with a formal tendon graft has varied between six-and-a-half weeks and forty-three weeks, with a mean of fifteen weeks. The most frequent reason for a long delay was initial failure to regain an adequate passive range. I n six cases there was an inordinate delay; in one there was great difficulty in regaining the passive range, one was at the patient's request, and four were recalcitrant about attending the follow-up clinic. The most important observation as regards timing is that the thickness of pseudosheath formation is not time dependent. Indeed some of the very late cases had thin sheaths, but in one case in which the second stage was carried out as early as six-and-a-half weeks, the sheath was found to be three millimetres in thickness. In this case biopsy showed the features normally associated with the new capsule, but gave no clue to its exuberance. In a further case with very thick sheath formation there was early progressive contracture of the finger necessitating its eventual amputation. PERIOD OF IMMOBILISATION
An impression has been formed that the initial return of movement following the two-stage procedure is often more rapid than following a conventional tendon graft (Geldmacher, 1969; Van der Meulen, 1971). Experience with two patients suggested that this could be hazardous and they are described in detail. It is suggested that too enthusiastic exercise in the early stages may cause too rapid a return of excursion, with rupture of the secondary vinculae, leading to ischaemic softening, graft rupture, and fibrosis as described below. While no statistical significance can be ascribed to these results, it is now our policy to immobilise for four weeks following the second stage and to allow only the gentlest active exercise during the first week of mobilisation. Case N o . 1. S.P., an eighteen-year-old shipwright, sustained glass lacerations of
the left hand with multiple tendon and nerve injuries. Silicone r u b b e r rods were inserted in the index and middle fingers are replaced with toe extensor grafts nine weeks later. He made good initial progress, but during the period of exercise he "felt something give way" in the middle finger, with a decrease in the range of movement, and subsequently failed to achieve any further improvement. Three months after the original graft the middle finger was re-explored. The graft was adherent throughout its length and a portion of the centre appeared to be attentuated and replaced by scar tissue. The graft was excised and replaced by a rod and subsequent tendon grafting gave a satisfactory outcome: He is now serving in the army. Case N o . 2. G.W., a thirty-two-year-old mechanic, sustained a ragged laceration
of his right hand, which became infected despite debridement and antibiotic cover. When healing was complete and the passive range regained, a silicone rubber rod was inserted in the ring finger. Eight weeks later this was replaced by The Hand--Vol. 8
No. 1
1976
67
Observations on the Use of Silicone Rubber Spacers in Tendon Graft S u r g e r y - A. G. Leonard and W. R. Dickie
a palmaris longus graft. During the sixth post-operative week the graft was felt to give way over the metacarpophalangeal joint, under an examining finger. H e failed to regain any further m o v e m e n t and at re-exploration the same picture of central necrosis and subsequent fibrosis of the graft was found. H e too has had both stages repeated and at four months after his second tendon graft was noted to have a flexion gap (nail to distal interphalangeal joint crease) of only 2 cms., with an extension lag of 45 ° at the distal interphalangeal joint. In the above two cases a good result has been achieved despite an initial poor result, by re-exploration and repetition of both stages of the procedure. This possibility has been suggested (Hunter, 1971) but has not to our knowledge been reported elsewhere. It is suggested that the nature of the initial injury and the age, occupation and motivation of the patient are factors which should be taken into account in a decision as to whether to e m b a r k on surgery of this nature. When these factors are favourable it would seem that a repetition of the two-stage procedure does not reduce the likelihood of a successful result. CONCLUSIONS
The salient points arising f r o m a review of this series of tendon grafts Secondary to silicone rubber rod insertion have been discussed. Excessive scarring was the most frequent indication for the procedure. The Bruner type of incision was used for approach, without complications. There was a wide variation in timing of the second stage and thickness of pseudosheath formation did not seem to be time dependent. It was found necessary to immobilise in flexion for longer than in the one-stage procedure. In two cases of graft rupture in the early stages of mobilisation, a good result was achieved after repetition of both stages, which procedure has not been reported elsewhere. ACKNOWLEDGEMENTS
We wish to record our gratitude to Mr. J. Colville, F.R.C.S., for allowing his cases to be included in this review, and to Miss L. McVea for her assistance in preparation of the manuscript. REFERENCES
BRUNER, J. M. (1973) Surgical Exposure Of Flexor Tendons In The Hand. Annals of the Royal College of Surgeons of England, 53: 84--94. COLVILLE, J. and DICKIE, W. R. (1969) Tendon Graft Length. British Journal of Plastic Surgery, 22: 37-40. COLVILLE, J. (1971) Haemostasis in Hand Surgery. Transactions of Fifth International Congress of Plastic and Reconstructive Surgery, Butterworths, Australia: 522-524. GELDMACHER, J. (1969) Die zweizeitige freie Beugesehnen transplantation Handchirurgie 1: 3, 109-120. HELAL, B. (1973) The Use Of Silicone Rubber Spacers In Flexor Tendon Surgery. The Hand, 5: 85-90. HUNTER, J. M. and SALISBURY, R. E. (1971) Flexor-Tendon Reconstruction in Severely Damaged Hands. A Two-Stage Procedure Using a Silicone-Dacron Reinforced Gliding Prosthesis Prior to Tendon Grafting. Journal of Bone and Joint Surgery, 53a: 829-858. NICOLLE, F. V. (1969) A Silastic Tendon Prosthesis As An Adjunct To Flexor Tendon Grafting: An Experimental And Clinical Evaluation. British Journal of Plastic Surgery, 22: 224-236. VAN DER MEULEN, J. C. (1971) Silastic Spacers In Tendon Grafting. British Journal of Plastic Surgery, 24: 166-173. 68
The HandmVol. 8
No. 1
1976