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Reconstruction of the thumb amputation at the carpometacarpal joint level by groin flap and second toe transfer
Injury, Int. J. Care Injured 44 (2013) 370–375
Contents lists available at SciVerse ScienceDirect
Injury journal homepage: www.elsevier.com/locate/injury
Reconstruction of the thumb amputation at the carpometacarpal joint level by groin flap and second toe transfer S. Raja Sabapathy *, Hari Venkatramani, Praveen Bhardwaj Department of Plastic Surgery, Hand Surgery, Reconstructive Microsurgery and Burns, Ganga Hospital, 313 Mettupalayam Road, Coimbatore, 641043, India
A R T I C L E I N F O
A B S T R A C T
Keywords: Thumb loss at Carpometacarpal (CMC) joint level Toe transfer Thumb reconstruction Groin flap Thumb avulsion amputations Microsurgery for thumb Post traumatic pollicisation Post traumatic thumb loss Considerations for thumb reconstruction
Introduction: Traumatic loss of thumb at the carpometacarpal (CMC) joint level is very disabling to an individual. Pollicisation is the recommended technique of reconstruction for loss of thumb at this level. On occasions, injury to the rest of the hand or amputation of additional fingers may make pollicisation an impossible option. Microsurgical transfer of second toe is an option in such situations. Although many large series of toe transfers are available in the literature, no series deals exclusively with this subset of patients. Materials and methods: Eight patients who had amputation of the thumb at or proximal to the CMC joint level were reconstructed by second toe transfer by us in the period 2002–2011. All had preliminary groin flap cover in the area of the thumb during the acute stage of treatment. Second toe with the metatarsal was transferred for thumb reconstruction after a mean duration of 3 months after flap cover. Patients were assessed for their ability to pinch, hold large objects and opposition achieved by Kapandji score. Average follow up is 4 years and 6 months with a minimum of 1 year. Results: All toe transfers survived. They reached their maximum functional potential by 1 year. All patients actively used the reconstructed thumb for day to day activities. Pinch was possible in all patients except two patients who did not have any fingers. Six of them registered grip strength of at least 50% of the opposite hand. When fingers were present, opposition was possible in all patients with Kapandji scores ranging from 5 to 8. Extent of usage was less in patients who did not have good function in other fingers. Conclusion: Second toe transfer is a viable option for reconstruction of thumb loss at or proximal to the CMC joint level. Proper planning of the preliminary flap cover determines the length of the thumb reconstruction. Strategic position of the transferred toe of adequate length and the functional status of the other fingers are important determinants of functional outcome. ß 2013 Elsevier Ltd. All rights reserved.
Introduction Amputation of the thumb at the carpometacarpal (CMC) joint level is very disabling to the individual. The resultant functional disability is graded to be as high as 40% of the hand. Adaptation of the individual following traumatic loss of thumb is more difficult and incomplete than in congenital loss of thumb. Pollicisation is the recommended method of reconstruction for thumb loss at the CMC joint level. In some instances, the trauma which resulted in the amputation of the thumb may in addition cause significant amount of skin and soft tissue loss and amputation of other fingers making option of pollicisation impossible. In such instances, we
* Corresponding author. Tel.: +91 422 2485000; fax: +91 422 2436444. E-mail address: [email protected] (S.R. Sabapathy). 0020–1383/$ – see front matter ß 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.injury.2013.01.012
need an alternate method of reconstruction. Toe transfer in such instances though technically challenging is probably an option. Large series of toe transfers to the hands have been published but no series specifically deals with the technical considerations associated with toe transfer for thumb amputation at CMC joint level and their outcome.1–5 In this article we are presenting our experience of reconstructing eight patients with amputation of the thumb at the CMC joint with second toe transfers with preliminary groin flap cover and the technical considerations which influence the outcome. Materials and methods During the period of 2002–2011 we had eight cases of proximal thumb amputation at or proximal to the carpometacarpal (CMC) joint. Table 1 details the nature of injury, associated injuries, type of soft tissue cover provided, skeletal fixation, tendons, nerves and
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371
Table 1 Patient details. Case no.
Nature of injury
Associated injury
Type of soft tissue cover
Skeletal fixation
Tendon repair (toe – digit)
Nerves repaired
Vessels repaired
1
Train accident
Index and middle total
Groin flap
Fixed to trapezium
Extensor to EDC,
Two plantar digital nerve to median
Radial artery
2
Machine injury
Index and middle total and ring at middle phalanx level
Groin flap
Fixed to trapezium
flexor to FDP Extensor to EPL, flexor to FPL
Two palmar digital nerves, radial cutaneous nerve
Radial artery
3
Road traffic accident
None
Groin flap
Base of second
Radial artery
4
Fodder machine
All fingers amputated
Groin flap
metacarpal Fixed to trapezium
5
Machine injury
None
Groin flap
Fixed to trapezium
6
Cracker blast injury
All fingers amputated
Groin flap
Base of second metacarpal
Extensor to EDC, flexor to FDP
7
Road traffic accident
Index finger at proximal phalanx base
Groin flap
Fixed to trapezium
Extensor to EPL, flexor to FPL
8
Cracker blast injury
Index total and middle finger at proximal phalanx
Groin flap
Fixed to trapezium
Extensor to EDC, flexor to FDP with tendon graft
Two palmar digital nerves, radial cutaneous nerve Two palmar digital nerve, radial cutaneous nerve Two palmar digital nerve, radial cutaneous nerve Two plantar nerves to median, radial cutaneous nerve Two palmar digital nerve, radial cutaneous nerve Two plantar digital nerves to median, radial cutaneous nerve
with tendon graft Extensor to EI, flexor to FPL Extensor to EDC, flexor to FDP tendon graft Extensor to EPL, flexor to FPL
Radial artery
Radial artery
Radial artery
Radial artery
Radial artery
Abbreviations: EDC, extensor digitorum communis; FDP, flexor digitorum profundus; EPL, extensor pollicis longus; FPL, flexor pollicis longus; EI, extensor indicis.
vessels repaired. All patients had preliminary groin flap cover in the region of the proposed thumb and skin grafts if necessary in the non-critical areas. Second toe transfer was done after a mean duration of 3 months after flap cover. All underwent supervised physiotherapy for a period of at least 6 months following toe transfer. Average follow up is 4 years and 6 months with a minimum of 1 year. Results All toe transfers survived. All of them appeared to reach their maximum functional potential by 1 year. They were evaluated for their ability to pinch, hold large objects and opposition achieved by Kapandji score (Table 2). All patients actively used the reconstructed thumb for day to day activities and were happy with the gains made by surgery (Fig. 1). Pinch was possible in all except two patients who did not have any fingers. Pinch enabled them to pick up small objects (Fig. 2), write comfortably but it was inadequate to register a reading in a pinch meter. All of them could hold a broad object (Fig. 2). Six of them registered grip strength of 50% of the opposite hand. In two patients who did not have any fingers, the transferred toe was used to hold objects with the stump of the little finger in one and with the metacarpals in the other hand. When fingers were present, opposition was possible in all patients, with Kapandji scores ranging from 5 to 8. When the remaining
fingers were fully functional, the patients used the hands very well and were almost able to do all activities. Extent of usage was less in patients who did not have good function in other fingers. In case no 5, there was in addition loss of flexor tendon of the index finger and secondary reconstruction was done after the toe transfer. Technical considerations The length of a normal thumb of an adult is about 12 cm from the CMC joint. It differs according to the size of the hand. For essential prehension following factors are important – sufficient length of the thumb to meet the available fingers, an adequate thumb web space, stability of the reconstructed thumb to facilitate pinch and grasp and a sensate thumb tip. In performing a toe transfer in these patients all four aspects have to be addressed. Preliminary flap cover Reconstruction of the thumb from the CMC joint level with toe transfer involves the need for a significant length of the metatarsal. Amputations of the thumb at this level generally require the addition of at least 5 cm of length in the metacarpal segment to bring it out of the palm.6 Harvesting great toe with metatarsal would lead to significant donor site morbidity and so second toe transfer is the preferred option. The length of the second toe distal to the web space is only about 3–4 cm. In the reconstruction of the
Table 2 Functional outcome of the reconstructed thumbs. Case no.
Pinch (reconstructed thumb reaches)
Ability to hold large objects
Kapandji score
Basic functional hand
1 2 3 4 5 6 7 8
Middle finger tip Stump of the middle finger Index tip
Yes Yes Yes
8 6 5
a
a
a
Index finger tip
Yes
5
b
b
b
Middle finger tip Ring finger tip
Yes Yes
6 6
Achieved Achieved Achieved No Achieved No Achieved Achieved
a b
The reconstructed thumb opposes to the ulnar post formed by the base of the proximal phalanx of the little finger. The reconstructed thumb opposes to the ulnar post formed by the head of the fourth and fifth metacarpals.
372
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Fig. 1. (a) 34-year-man with crush-avulsion amputation of the thumb at the CMC joint level with associated index finger amputation. (b) X-ray showing the thumb amputation at the CMC joint level. (c) Soft tissue cover provided by groin flap. Note the flap pointing in the direction of future thumb. (d) Post debridement X-ray. (e) Grip of the hand. (f) Span of the hand to hold big objects. (g) Tripod pinch achieved. (h) Lateral pinch achieved. (i) X-ray showing good union of the metatarsal base to the trapezium.
thumb at this level at least 5 cm of second metatarsal would need soft tissue cover. This has to be provided by a preliminary flap cover. So almost always this reconstruction has to be done in stages and primary toe transfer reconstruction at this level will be a too extensive undertaking. The soft tissue cover is provided by a pedicled groin flap. Proper planning of the pedicled groin flap sets the stage for successful completion of the reconstruction. Two factors have to be considered. One is the length of the flap. The flap needs to project at least 6–8 cm from the base. A short flap limits the length of the metatarsal that could be taken during toe transfer. This issue will affect the final functional outcome. The second factor is that the flap has to point in the direction of the future thumb (Fig. 1c). The flap has to be oriented in that direction while insetting of the flap into the hand. If it points in any other way it affects the aesthetic aspect of the reconstruction. At the time of toe transfer the flap is split into two from the apex and access is gained to the base of the thumb. Since no part of the inset is damaged the flap could be radically thinned and shaped as per need to get a good aesthetic outcome. The incision is extended into the dorsum to access the veins, extensor tendons, radial cutaneous nerves and the arteries. On the palmar side, incision is extended to source recipient nerves and flexor tendons.
Stabilisation of the skeleton This is a critical part of the operation. The metatarsal of the second toe will have to be fixed to the carpal bones. No joint is being formed here and so strategic fixation of the toe is essential. It is fixed in such a way that the tips of the remaining fingers are able to oppose the tip of the transferred toe. The length of the metatarsal used will depend upon the status and movement of remaining fingers and the adequacy of the flap cover. The whole success of the operation depends upon this step. The thumb is fixed in a position of abduction to create a good first web space and pronated so that the pulp of the transferred toe points to the pulp of the remaining fingers. We have used a single axial K-wire for fixation in all the cases, with the wire distally coming out through the proximal phalanx. In six cases the metatarsal was fixed to the trapezium and in the rest two to the base of the second metacarpal. No bone grafts were used. Tendon and nerve repairs A long length of flexor tendon has to be taken while harvesting the second toe, because the flexor of the thumb will be found only in the forearm. In case of avulsion amputation of
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Fig. 2. (a) 11-year-boy who presented to us following a cracker blast injury causing loss of the thumb at the CMC joint level with associated amputation of the index and middle fingers. (b) X-ray showing thumb amputation at the CMC joint level. (c) Toe transfer dissected with 4 cm of metatarsal to meet the ring and little fingers. (d) Tripod
the thumb flexor pollicis longus may not be available at all. In our series of eight cases, only in one case (case no. 7) the flexor pollicis longus was available proximally for repair to the flexor tendon of the toe, in four cases a flexor of the amputated finger was used as a flexor of the reconstructed thumb and in three cases tendon graft was required to bridge the gap between the flexor tendon (in the distal third of forearm) and the toe flexor (Table 1). Since the base is fixed and the thenar muscles are not available in these reconstructions the only source of power to the transferred toe is by the flexor tendon repair. So this has to be done with care. The flexor tendon has to be routed through the carpal tunnel. Superficial routing of the repair or the transfer will result in abduction and not provide power to the transferred toe. Harvesting a long length of the flexor tendon is more difficult than harvesting a long length of extensor from the dorsum of the foot. If index finger is intact, the presence of extensor indicis makes extensor reconstruction easy. In our series of eight cases, in three patients proximal extensor pollicis longus tendon was available for repair to the extensor tendon of the toe, in four cases the extensor tendon of the injured fingers and in one case (case no. 3) the extensor indicis
tendon was transferred to the toe extensor tendon (Table 1). The toe interphalangeal (IP) joints are basically flexed and to give it a good position the extensors are repaired with sufficient amount of tension to keep the IP joints in neutral position. Apart from the strategic positioning of the transferred toe, sensation at the pulp is essential for good function. In avulsion amputations it may not be possible to secure a good digital nerve and commonly the median nerve at the carpal canal will be the nerve available. If a stump of the nerves to the thumb is available it could be sutured or else the ulnar side digital nerve of index or the middle could be used as a transfer to provide sensation to the thumb. Nerve repair was done in all the eight cases in our series. In all the eight cases the plantar nerves were repaired, in three cases they were sutured proximally to the median nerve at the carpal tunnel and in five cases to the digital nerve of the thumb or the injured index finger (Table 1). The dorsal digital nerve of the toe was repaired in seven out of eight cases and the cooptation was done to the radial cutaneous nerve (Table 1). In these patients we always try to repair the dorsal digital nerves. Branches of the radial cutaneous nerve are easily available
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on the dorsum of the hand and repairing them will have significant advantage. We feel that the sensory input that comes after repair of the dorsal nerves does migrate to the volar side and improves sensations. Status of the other fingers in the Hand The reconstructed second toe will act as the stable post with significant movement possible only at the IP joints and MCP joint. Ultimately the functional status will depend upon the other fingers reaching out to the reconstructed thumb. Six of our eight patients had significant injury to other fingers. In one patient there was associated amputation of the index finger (case 7). In three cases there was associated amputation of the index and the middle fingers, but since the ring and the little were functioning well good pinch and grip was possible. In two cases all other fingers also were lost during the injury and these patients were using the transferred toe to make a palmar contact (cases 4 and 6). In two patients (cases 3 and 5) all the fingers were present but there was extensive soft tissue loss around the index finger which was covered by flap. Absence of definite veins and the possible difficulty in dissecting the arteries precluded the option of pollicisation. Rehabilitation Regular post operative protocol of microsurgery flap monitoring was practiced in the post operative period. K-wires were removed at 4 weeks and a protective splint was worn for another 6 weeks. Mobilisation of the metacarpophalangeal and interphalangeal joints of the toe was done after removal of the wire. All developed adequate sensation and never developed trophic changes. Patients started using the hand from 10th week post surgery. Discussion Thumb is extremely important for hand function and it is very well reflected by the amount of literature on its reconstruction following traumatic loss. The determinants for good functional outcome are the correct position of the thumb opposable to the existing fingers, a mobile CMC joint, sensate and non-tender tip, stability of the interphalangeal and metacarpophalangeal joint and strength adequate to resist the force of the fingers. Mobility of the CMC joint is considered very important and hence when the thumb is lost at that level the choice of reconstruction is pollicisation which can provide the CMC joint. On rare occasions pollicisation becomes impossible due to amputation of other fingers or severe damage to the structures in the palm which makes the mandatory dissection for pollicisation impossible. These patients would have also lost the thenar muscles and it is quite possible that there is more extensive soft tissue loss requiring soft tissue cover. This article addresses that specific group of patients and the technical considerations which determine good outcome. As in any mutilated hand injury management, primary healing of the soft tissues is important. Amputation exposes bones on the radial border of the hand and flap cover was needed in all the patients. Adequate flap cover was provided to cover the bare metatarsal during toe transfer in the next stage. Pinal et al. in some instances have used the dorsalis pedis fasciosubcutaneous toe free flap in a single stage reconstruction.7 This could be used when the soft tissue loss is minimal. In extensive injuries it is safer to do a staged procedure with a preliminary groin flap and then the donor deformity in the foot is minimal.
Adequate care has to be taken to position the thumb in a strategic position. Littler while writing about the thumb reconstruction has said that, ‘it is not on the length, strength or mobility of the thumb but on the strategic position of the thumb and the sensation of the finger tip rests the power of the human hand’.8 The axiom is very true for reconstruction of the thumb at this level. This is vital because no movement is possible at the CMC joint. If mispositioned, both pinch and grasp will become impossible. The movement of the fingers is assessed and the length and the position so adjusted to enable prehension. Length adjustment of the reconstructed thumb is done at the metatarsal level. Fusion is obtained by telescoping the metatarsal into the trapezium if present or the base of the second metacarpal. Since no movement is possible at the base of the newly created thumb, positioning is important. Lin et al. stated that the functional restoration of thumb opposition and function for amputations proximal to the metacarpophalangeal joint cannot be achieved adequately with a toe flap alone.9 When Pollicisation was not possible they preferred osteoplastic reconstruction and over that secondary toe transfer for this level of amputation. In their series of 24 cases there were only 3 cases with thumb loss at the CMC level. After osteoplastic reconstruction two did not have opposition and one reached the stage of 3 on the Kapandji scale. One of these patients reached a Kapandji score of 6 after superadded toe transfer and opponensplasty. In our series by proper positioning of the toe in a flap, all patients reached opposition of 5 and above on the Kapandji scale (except for the two patients who had lost all fingers). Amputations at this level also involve loss of thenar muscles. Only flexion and extension at the IP and MCP joints of the toes are possible. It was surprising to us that good function could be achieved by mere proper positioning and good repair of long flexors and extensors. The bulky flap probably also adds to the stability of the reconstructed thumb. Since the base is fixed, there is no scope for secondary opponensplasty and this was not needed as per our experience. Since the ultimate function also depends upon the status and function of the remaining fingers it is imperative that full function is obtained in the remaining digits before embarking on toe transfer. Having this sequence of reconstruction in mind will encourage us to concentrate on the other injuries primarily. Conclusion Proximal thumb amputation at the CMC joint level is very disabling to an individual. Pollicisation is the recommended form of reconstruction at this level. On occasions when this is not possible due to the injury to the rest of the hand, preliminary groin flap cover and second toe transfer is a good method of reconstruction. Attention to detail in providing flap cover, optimising function in the remaining fingers, strategic positioning of the transferred toe of adequate length will ensure a good functional outcome. Conflict of interest There is no conflict of interest to declare. References 1. Valauri FA, Buncke HJ. Thumb reconstruction-great toe transfer. Clin Plast Surg 1989;16:475–89. 2. Wei FC, Chen HC. Microsurgical thumb reconstruction with toe transfer: selection of various techniques. Plast Reconstr Surg 1994;93:345–51. 3. Gu YD, Zhang GM, Cheng DS, Yan JG, Chen XM. Free toe transfer for thumb and finger reconstruction in 300 cases. Plast Reconstr Surg 1993;91:693–700.
S.R. Sabapathy et al. / Injury, Int. J. Care Injured 44 (2013) 370–375 4. Kotkansalo T, Vilkki S, Elo P, Luukkaala T. Long-term functional results of microvascular toe-to-thumb reconstruction. J Hand Surg 2011;36B:194–204. 5. Frykman GK, O’Brien BM, Morrison WA, MacLeod AM. Functional evaluation of the hand and foot after one-stage toe-to-hand transfer. J Hand Surg 1986;11A: 9–17. 6. Stickland JW, Kleinman WB. Thumb reconstruction. In: Green DP, editor. Operative hand surgery. 3rd ed. New York: Churchill Livingstone; 1993. ˜ al F, Garcı´a-Bernal FJ, Delgado J, Regalado J, Sanmartı´n M, Garcı´a-Ferna´n7. del Pin dez D. Overcoming soft-tissue deficiency in toe-to-hand transfer using a dorsalis
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pedis fasciosubcutaneous toe free flap: surgical technique. J Hand Surg 2005;30A:111–9. 8. Littler JW, Finger pollicisation for traumatic loss.May JW, Littler JW, editors. Plastic surgery, vol. 8. Philadelphia: Saunders; 1990 . p.
5135–52. 9. Lin CH, Mardini S, Lin YT, Lin CH, Chen CT, Wei FC. Osteoplastic thumb ray restoration with or without secondary toe transfer for reconstruction of opposable basic hand function. Plast Reconstr Surg 2008;121: 1288–97.
Contents lists available at SciVerse ScienceDirect
Injury journal homepage: www.elsevier.com/locate/injury
Reconstruction of the thumb amputation at the carpometacarpal joint level by groin flap and second toe transfer S. Raja Sabapathy *, Hari Venkatramani, Praveen Bhardwaj Department of Plastic Surgery, Hand Surgery, Reconstructive Microsurgery and Burns, Ganga Hospital, 313 Mettupalayam Road, Coimbatore, 641043, India
A R T I C L E I N F O
A B S T R A C T
Keywords: Thumb loss at Carpometacarpal (CMC) joint level Toe transfer Thumb reconstruction Groin flap Thumb avulsion amputations Microsurgery for thumb Post traumatic pollicisation Post traumatic thumb loss Considerations for thumb reconstruction
Introduction: Traumatic loss of thumb at the carpometacarpal (CMC) joint level is very disabling to an individual. Pollicisation is the recommended technique of reconstruction for loss of thumb at this level. On occasions, injury to the rest of the hand or amputation of additional fingers may make pollicisation an impossible option. Microsurgical transfer of second toe is an option in such situations. Although many large series of toe transfers are available in the literature, no series deals exclusively with this subset of patients. Materials and methods: Eight patients who had amputation of the thumb at or proximal to the CMC joint level were reconstructed by second toe transfer by us in the period 2002–2011. All had preliminary groin flap cover in the area of the thumb during the acute stage of treatment. Second toe with the metatarsal was transferred for thumb reconstruction after a mean duration of 3 months after flap cover. Patients were assessed for their ability to pinch, hold large objects and opposition achieved by Kapandji score. Average follow up is 4 years and 6 months with a minimum of 1 year. Results: All toe transfers survived. They reached their maximum functional potential by 1 year. All patients actively used the reconstructed thumb for day to day activities. Pinch was possible in all patients except two patients who did not have any fingers. Six of them registered grip strength of at least 50% of the opposite hand. When fingers were present, opposition was possible in all patients with Kapandji scores ranging from 5 to 8. Extent of usage was less in patients who did not have good function in other fingers. Conclusion: Second toe transfer is a viable option for reconstruction of thumb loss at or proximal to the CMC joint level. Proper planning of the preliminary flap cover determines the length of the thumb reconstruction. Strategic position of the transferred toe of adequate length and the functional status of the other fingers are important determinants of functional outcome. ß 2013 Elsevier Ltd. All rights reserved.
Introduction Amputation of the thumb at the carpometacarpal (CMC) joint level is very disabling to the individual. The resultant functional disability is graded to be as high as 40% of the hand. Adaptation of the individual following traumatic loss of thumb is more difficult and incomplete than in congenital loss of thumb. Pollicisation is the recommended method of reconstruction for thumb loss at the CMC joint level. In some instances, the trauma which resulted in the amputation of the thumb may in addition cause significant amount of skin and soft tissue loss and amputation of other fingers making option of pollicisation impossible. In such instances, we
* Corresponding author. Tel.: +91 422 2485000; fax: +91 422 2436444. E-mail address: [email protected] (S.R. Sabapathy). 0020–1383/$ – see front matter ß 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.injury.2013.01.012
need an alternate method of reconstruction. Toe transfer in such instances though technically challenging is probably an option. Large series of toe transfers to the hands have been published but no series specifically deals with the technical considerations associated with toe transfer for thumb amputation at CMC joint level and their outcome.1–5 In this article we are presenting our experience of reconstructing eight patients with amputation of the thumb at the CMC joint with second toe transfers with preliminary groin flap cover and the technical considerations which influence the outcome. Materials and methods During the period of 2002–2011 we had eight cases of proximal thumb amputation at or proximal to the carpometacarpal (CMC) joint. Table 1 details the nature of injury, associated injuries, type of soft tissue cover provided, skeletal fixation, tendons, nerves and
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371
Table 1 Patient details. Case no.
Nature of injury
Associated injury
Type of soft tissue cover
Skeletal fixation
Tendon repair (toe – digit)
Nerves repaired
Vessels repaired
1
Train accident
Index and middle total
Groin flap
Fixed to trapezium
Extensor to EDC,
Two plantar digital nerve to median
Radial artery
2
Machine injury
Index and middle total and ring at middle phalanx level
Groin flap
Fixed to trapezium
flexor to FDP Extensor to EPL, flexor to FPL
Two palmar digital nerves, radial cutaneous nerve
Radial artery
3
Road traffic accident
None
Groin flap
Base of second
Radial artery
4
Fodder machine
All fingers amputated
Groin flap
metacarpal Fixed to trapezium
5
Machine injury
None
Groin flap
Fixed to trapezium
6
Cracker blast injury
All fingers amputated
Groin flap
Base of second metacarpal
Extensor to EDC, flexor to FDP
7
Road traffic accident
Index finger at proximal phalanx base
Groin flap
Fixed to trapezium
Extensor to EPL, flexor to FPL
8
Cracker blast injury
Index total and middle finger at proximal phalanx
Groin flap
Fixed to trapezium
Extensor to EDC, flexor to FDP with tendon graft
Two palmar digital nerves, radial cutaneous nerve Two palmar digital nerve, radial cutaneous nerve Two palmar digital nerve, radial cutaneous nerve Two plantar nerves to median, radial cutaneous nerve Two palmar digital nerve, radial cutaneous nerve Two plantar digital nerves to median, radial cutaneous nerve
with tendon graft Extensor to EI, flexor to FPL Extensor to EDC, flexor to FDP tendon graft Extensor to EPL, flexor to FPL
Radial artery
Radial artery
Radial artery
Radial artery
Radial artery
Abbreviations: EDC, extensor digitorum communis; FDP, flexor digitorum profundus; EPL, extensor pollicis longus; FPL, flexor pollicis longus; EI, extensor indicis.
vessels repaired. All patients had preliminary groin flap cover in the region of the proposed thumb and skin grafts if necessary in the non-critical areas. Second toe transfer was done after a mean duration of 3 months after flap cover. All underwent supervised physiotherapy for a period of at least 6 months following toe transfer. Average follow up is 4 years and 6 months with a minimum of 1 year. Results All toe transfers survived. All of them appeared to reach their maximum functional potential by 1 year. They were evaluated for their ability to pinch, hold large objects and opposition achieved by Kapandji score (Table 2). All patients actively used the reconstructed thumb for day to day activities and were happy with the gains made by surgery (Fig. 1). Pinch was possible in all except two patients who did not have any fingers. Pinch enabled them to pick up small objects (Fig. 2), write comfortably but it was inadequate to register a reading in a pinch meter. All of them could hold a broad object (Fig. 2). Six of them registered grip strength of 50% of the opposite hand. In two patients who did not have any fingers, the transferred toe was used to hold objects with the stump of the little finger in one and with the metacarpals in the other hand. When fingers were present, opposition was possible in all patients, with Kapandji scores ranging from 5 to 8. When the remaining
fingers were fully functional, the patients used the hands very well and were almost able to do all activities. Extent of usage was less in patients who did not have good function in other fingers. In case no 5, there was in addition loss of flexor tendon of the index finger and secondary reconstruction was done after the toe transfer. Technical considerations The length of a normal thumb of an adult is about 12 cm from the CMC joint. It differs according to the size of the hand. For essential prehension following factors are important – sufficient length of the thumb to meet the available fingers, an adequate thumb web space, stability of the reconstructed thumb to facilitate pinch and grasp and a sensate thumb tip. In performing a toe transfer in these patients all four aspects have to be addressed. Preliminary flap cover Reconstruction of the thumb from the CMC joint level with toe transfer involves the need for a significant length of the metatarsal. Amputations of the thumb at this level generally require the addition of at least 5 cm of length in the metacarpal segment to bring it out of the palm.6 Harvesting great toe with metatarsal would lead to significant donor site morbidity and so second toe transfer is the preferred option. The length of the second toe distal to the web space is only about 3–4 cm. In the reconstruction of the
Table 2 Functional outcome of the reconstructed thumbs. Case no.
Pinch (reconstructed thumb reaches)
Ability to hold large objects
Kapandji score
Basic functional hand
1 2 3 4 5 6 7 8
Middle finger tip Stump of the middle finger Index tip
Yes Yes Yes
8 6 5
a
a
a
Index finger tip
Yes
5
b
b
b
Middle finger tip Ring finger tip
Yes Yes
6 6
Achieved Achieved Achieved No Achieved No Achieved Achieved
a b
The reconstructed thumb opposes to the ulnar post formed by the base of the proximal phalanx of the little finger. The reconstructed thumb opposes to the ulnar post formed by the head of the fourth and fifth metacarpals.
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Fig. 1. (a) 34-year-man with crush-avulsion amputation of the thumb at the CMC joint level with associated index finger amputation. (b) X-ray showing the thumb amputation at the CMC joint level. (c) Soft tissue cover provided by groin flap. Note the flap pointing in the direction of future thumb. (d) Post debridement X-ray. (e) Grip of the hand. (f) Span of the hand to hold big objects. (g) Tripod pinch achieved. (h) Lateral pinch achieved. (i) X-ray showing good union of the metatarsal base to the trapezium.
thumb at this level at least 5 cm of second metatarsal would need soft tissue cover. This has to be provided by a preliminary flap cover. So almost always this reconstruction has to be done in stages and primary toe transfer reconstruction at this level will be a too extensive undertaking. The soft tissue cover is provided by a pedicled groin flap. Proper planning of the pedicled groin flap sets the stage for successful completion of the reconstruction. Two factors have to be considered. One is the length of the flap. The flap needs to project at least 6–8 cm from the base. A short flap limits the length of the metatarsal that could be taken during toe transfer. This issue will affect the final functional outcome. The second factor is that the flap has to point in the direction of the future thumb (Fig. 1c). The flap has to be oriented in that direction while insetting of the flap into the hand. If it points in any other way it affects the aesthetic aspect of the reconstruction. At the time of toe transfer the flap is split into two from the apex and access is gained to the base of the thumb. Since no part of the inset is damaged the flap could be radically thinned and shaped as per need to get a good aesthetic outcome. The incision is extended into the dorsum to access the veins, extensor tendons, radial cutaneous nerves and the arteries. On the palmar side, incision is extended to source recipient nerves and flexor tendons.
Stabilisation of the skeleton This is a critical part of the operation. The metatarsal of the second toe will have to be fixed to the carpal bones. No joint is being formed here and so strategic fixation of the toe is essential. It is fixed in such a way that the tips of the remaining fingers are able to oppose the tip of the transferred toe. The length of the metatarsal used will depend upon the status and movement of remaining fingers and the adequacy of the flap cover. The whole success of the operation depends upon this step. The thumb is fixed in a position of abduction to create a good first web space and pronated so that the pulp of the transferred toe points to the pulp of the remaining fingers. We have used a single axial K-wire for fixation in all the cases, with the wire distally coming out through the proximal phalanx. In six cases the metatarsal was fixed to the trapezium and in the rest two to the base of the second metacarpal. No bone grafts were used. Tendon and nerve repairs A long length of flexor tendon has to be taken while harvesting the second toe, because the flexor of the thumb will be found only in the forearm. In case of avulsion amputation of
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Fig. 2. (a) 11-year-boy who presented to us following a cracker blast injury causing loss of the thumb at the CMC joint level with associated amputation of the index and middle fingers. (b) X-ray showing thumb amputation at the CMC joint level. (c) Toe transfer dissected with 4 cm of metatarsal to meet the ring and little fingers. (d) Tripod
the thumb flexor pollicis longus may not be available at all. In our series of eight cases, only in one case (case no. 7) the flexor pollicis longus was available proximally for repair to the flexor tendon of the toe, in four cases a flexor of the amputated finger was used as a flexor of the reconstructed thumb and in three cases tendon graft was required to bridge the gap between the flexor tendon (in the distal third of forearm) and the toe flexor (Table 1). Since the base is fixed and the thenar muscles are not available in these reconstructions the only source of power to the transferred toe is by the flexor tendon repair. So this has to be done with care. The flexor tendon has to be routed through the carpal tunnel. Superficial routing of the repair or the transfer will result in abduction and not provide power to the transferred toe. Harvesting a long length of the flexor tendon is more difficult than harvesting a long length of extensor from the dorsum of the foot. If index finger is intact, the presence of extensor indicis makes extensor reconstruction easy. In our series of eight cases, in three patients proximal extensor pollicis longus tendon was available for repair to the extensor tendon of the toe, in four cases the extensor tendon of the injured fingers and in one case (case no. 3) the extensor indicis
tendon was transferred to the toe extensor tendon (Table 1). The toe interphalangeal (IP) joints are basically flexed and to give it a good position the extensors are repaired with sufficient amount of tension to keep the IP joints in neutral position. Apart from the strategic positioning of the transferred toe, sensation at the pulp is essential for good function. In avulsion amputations it may not be possible to secure a good digital nerve and commonly the median nerve at the carpal canal will be the nerve available. If a stump of the nerves to the thumb is available it could be sutured or else the ulnar side digital nerve of index or the middle could be used as a transfer to provide sensation to the thumb. Nerve repair was done in all the eight cases in our series. In all the eight cases the plantar nerves were repaired, in three cases they were sutured proximally to the median nerve at the carpal tunnel and in five cases to the digital nerve of the thumb or the injured index finger (Table 1). The dorsal digital nerve of the toe was repaired in seven out of eight cases and the cooptation was done to the radial cutaneous nerve (Table 1). In these patients we always try to repair the dorsal digital nerves. Branches of the radial cutaneous nerve are easily available
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on the dorsum of the hand and repairing them will have significant advantage. We feel that the sensory input that comes after repair of the dorsal nerves does migrate to the volar side and improves sensations. Status of the other fingers in the Hand The reconstructed second toe will act as the stable post with significant movement possible only at the IP joints and MCP joint. Ultimately the functional status will depend upon the other fingers reaching out to the reconstructed thumb. Six of our eight patients had significant injury to other fingers. In one patient there was associated amputation of the index finger (case 7). In three cases there was associated amputation of the index and the middle fingers, but since the ring and the little were functioning well good pinch and grip was possible. In two cases all other fingers also were lost during the injury and these patients were using the transferred toe to make a palmar contact (cases 4 and 6). In two patients (cases 3 and 5) all the fingers were present but there was extensive soft tissue loss around the index finger which was covered by flap. Absence of definite veins and the possible difficulty in dissecting the arteries precluded the option of pollicisation. Rehabilitation Regular post operative protocol of microsurgery flap monitoring was practiced in the post operative period. K-wires were removed at 4 weeks and a protective splint was worn for another 6 weeks. Mobilisation of the metacarpophalangeal and interphalangeal joints of the toe was done after removal of the wire. All developed adequate sensation and never developed trophic changes. Patients started using the hand from 10th week post surgery. Discussion Thumb is extremely important for hand function and it is very well reflected by the amount of literature on its reconstruction following traumatic loss. The determinants for good functional outcome are the correct position of the thumb opposable to the existing fingers, a mobile CMC joint, sensate and non-tender tip, stability of the interphalangeal and metacarpophalangeal joint and strength adequate to resist the force of the fingers. Mobility of the CMC joint is considered very important and hence when the thumb is lost at that level the choice of reconstruction is pollicisation which can provide the CMC joint. On rare occasions pollicisation becomes impossible due to amputation of other fingers or severe damage to the structures in the palm which makes the mandatory dissection for pollicisation impossible. These patients would have also lost the thenar muscles and it is quite possible that there is more extensive soft tissue loss requiring soft tissue cover. This article addresses that specific group of patients and the technical considerations which determine good outcome. As in any mutilated hand injury management, primary healing of the soft tissues is important. Amputation exposes bones on the radial border of the hand and flap cover was needed in all the patients. Adequate flap cover was provided to cover the bare metatarsal during toe transfer in the next stage. Pinal et al. in some instances have used the dorsalis pedis fasciosubcutaneous toe free flap in a single stage reconstruction.7 This could be used when the soft tissue loss is minimal. In extensive injuries it is safer to do a staged procedure with a preliminary groin flap and then the donor deformity in the foot is minimal.
Adequate care has to be taken to position the thumb in a strategic position. Littler while writing about the thumb reconstruction has said that, ‘it is not on the length, strength or mobility of the thumb but on the strategic position of the thumb and the sensation of the finger tip rests the power of the human hand’.8 The axiom is very true for reconstruction of the thumb at this level. This is vital because no movement is possible at the CMC joint. If mispositioned, both pinch and grasp will become impossible. The movement of the fingers is assessed and the length and the position so adjusted to enable prehension. Length adjustment of the reconstructed thumb is done at the metatarsal level. Fusion is obtained by telescoping the metatarsal into the trapezium if present or the base of the second metacarpal. Since no movement is possible at the base of the newly created thumb, positioning is important. Lin et al. stated that the functional restoration of thumb opposition and function for amputations proximal to the metacarpophalangeal joint cannot be achieved adequately with a toe flap alone.9 When Pollicisation was not possible they preferred osteoplastic reconstruction and over that secondary toe transfer for this level of amputation. In their series of 24 cases there were only 3 cases with thumb loss at the CMC level. After osteoplastic reconstruction two did not have opposition and one reached the stage of 3 on the Kapandji scale. One of these patients reached a Kapandji score of 6 after superadded toe transfer and opponensplasty. In our series by proper positioning of the toe in a flap, all patients reached opposition of 5 and above on the Kapandji scale (except for the two patients who had lost all fingers). Amputations at this level also involve loss of thenar muscles. Only flexion and extension at the IP and MCP joints of the toes are possible. It was surprising to us that good function could be achieved by mere proper positioning and good repair of long flexors and extensors. The bulky flap probably also adds to the stability of the reconstructed thumb. Since the base is fixed, there is no scope for secondary opponensplasty and this was not needed as per our experience. Since the ultimate function also depends upon the status and function of the remaining fingers it is imperative that full function is obtained in the remaining digits before embarking on toe transfer. Having this sequence of reconstruction in mind will encourage us to concentrate on the other injuries primarily. Conclusion Proximal thumb amputation at the CMC joint level is very disabling to an individual. Pollicisation is the recommended form of reconstruction at this level. On occasions when this is not possible due to the injury to the rest of the hand, preliminary groin flap cover and second toe transfer is a good method of reconstruction. Attention to detail in providing flap cover, optimising function in the remaining fingers, strategic positioning of the transferred toe of adequate length will ensure a good functional outcome. Conflict of interest There is no conflict of interest to declare. References 1. Valauri FA, Buncke HJ. Thumb reconstruction-great toe transfer. Clin Plast Surg 1989;16:475–89. 2. Wei FC, Chen HC. Microsurgical thumb reconstruction with toe transfer: selection of various techniques. Plast Reconstr Surg 1994;93:345–51. 3. Gu YD, Zhang GM, Cheng DS, Yan JG, Chen XM. Free toe transfer for thumb and finger reconstruction in 300 cases. Plast Reconstr Surg 1993;91:693–700.
S.R. Sabapathy et al. / Injury, Int. J. Care Injured 44 (2013) 370–375 4. Kotkansalo T, Vilkki S, Elo P, Luukkaala T. Long-term functional results of microvascular toe-to-thumb reconstruction. J Hand Surg 2011;36B:194–204. 5. Frykman GK, O’Brien BM, Morrison WA, MacLeod AM. Functional evaluation of the hand and foot after one-stage toe-to-hand transfer. J Hand Surg 1986;11A: 9–17. 6. Stickland JW, Kleinman WB. Thumb reconstruction. In: Green DP, editor. Operative hand surgery. 3rd ed. New York: Churchill Livingstone; 1993. ˜ al F, Garcı´a-Bernal FJ, Delgado J, Regalado J, Sanmartı´n M, Garcı´a-Ferna´n7. del Pin dez D. Overcoming soft-tissue deficiency in toe-to-hand transfer using a dorsalis
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pedis fasciosubcutaneous toe free flap: surgical technique. J Hand Surg 2005;30A:111–9. 8. Littler JW, Finger pollicisation for traumatic loss.May JW, Littler JW, editors. Plastic surgery, vol. 8. Philadelphia: Saunders; 1990 . p.
5135–52. 9. Lin CH, Mardini S, Lin YT, Lin CH, Chen CT, Wei FC. Osteoplastic thumb ray restoration with or without secondary toe transfer for reconstruction of opposable basic hand function. Plast Reconstr Surg 2008;121: 1288–97.