Fig. 9.1
(a–f) Total great-toe transfer to an unreplantable thumb amputation at proximal phalanx. (a) Coverage reconstruction of the amputation stump of the thumb with a pedicle groin flap before a total great-toe transfer. (b) Design of a total great-toe transfer at the donor left foot. (c) Harvested great toe. (d) Preparation of the recipient site. Note the use of transferred flexor digitorum profundus (FDP) of the ring finger for flexor function of the new thumb. (e, f) Appearance 3 months after toe-to-thumb reconstruction
Fig. 9.2
(a–g) Trimmed great-toe transfer to a thumb after failed replantation. (a) Thumb stump appearance after failed replantation. (b) Both proximal, distal phalange and interphalangeal joint trimmed smaller. (c) Appearance of the trimmed great toe after being detached from its donor site. (d–g) Appearance and function of the new thumb 7 years after reconstruction
Total or trimmed great-toe transfer to replace a thumb is indicated when the amputation level is at the proximal phalanx or metacarpal bone. It aims to reconstruct a new thumb with good range of motion and broad pulp surface for more powerful pinch. The trimmed transplantation of the great toe [14, 43, 63] is indicated when there is an unacceptable size difference between the thumb on the normal contralateral side and the great toe, especially when a mobile IP joint is desired. In the trimmed great-toe technique, both skin and skeleton including proximal and distal phalanges as well as interphalangeal joint are reduced to increase resemblance to the thumb. The nail bed is not trimmed to avoid nail deformity. For amputations distal to IP joints, functional deficit is usually less [91, 92] and some patients may not prefer any reconstruction [93]. However, partial great-toe transfer or modified wraparound flap can achieve good satisfactory results [26]. Degloving injuries with intact skeleton can be managed with wraparound techniques either from the great or second toe [94, 95]. In both variants, the donor proximal phalanx is osteotomized, preserving at least 1 cm of the base of the proximal phalanx, which maintains foot span for a better appearance and to preserve push-off function of the donor foot [47].
Total or Partial Transplantation of the Second Toe (Figs. 9.3a–e and 9.4a–f)
Fig. 9.3
(a–e) Two total second-toe transfers to right index and middle finger. (a) Right index, middle, and ring finger amputated at proximal interphalangeal joint, proximal phalanx, and proximal phalanx respectively. (b) Two second toes from both feet harvested. (c–e) Appearance and function of transferred toes (new fingers) 3 years after reconstruction
Fig. 9.4
(a–f) Partial second-toe transfer to an unreplantable distal index finger. (a, b) Appearance of amputation stump. (c, d) Appearance of reconstructed index finger 4 years after partial second-toe transfer. (e, f) Function of the reconstructed index finger 2 years after partial second-toe transfer
The second-toe transfer is another reliable procedure after failed replantation; it can be transferred for reconstruction of either the thumb or fingers. Thumb amputation proximal to (CMC) joint may, in particular, benefit from lesser-toe transfer that provides valuable bone length up to proximal metatarsus, which contrasts with the proximal phalanx harvest level in great-toe transfer. Partial transplantation of the second toe is used for finger amputations distal to the insertion of the superficial flexor tendon, whereas total transplantation is used for the reconstruction of more proximal finger amputations [12, 52, 74, 84, 87, 96–102].
Combined Transplantation of the Second and Third Toes (Fig. 9.5a–e)
Fig. 9.5
(a–e) Type I metacarpal hand reconstructed with a combined second- and third-toe transfer. (a) Type I metacarpal hand initially treated with a pedicled groin flap for coverage. (b) Harvested combined second and third toe. (c–e) Appearance and function 2 years after combined second- and third-toe transfer reconstruction
Combined second- and third-toe transfer is indicated for reconstruction of two adjacent fingers after traumatic amputation proximal to the digital webs. Advantages of combined second and third tow transfer over bilateral transplantation of both second toes are multiple. First, only a single set of recipient vessels is required; second, less operative time is required; third, potential morbidity in the donor site is limited to one foot [103].
The level of digit amputation is used to determine the osteotomy level, and we recommend that the second and third plantar arteries be preserved to be used for a second arterial anastomosis when arterial perfusion to third toe is in doubt [104].
Postoperative Care
Directly after surgery, aspirin (325 mg/day) is administered for 2 weeks to reduce the risk of platelet aggregation. Dextran is not routinely used due to risk of systemic complications, particularly pulmonary edema in elderly patients (see Chap. 8). Heparin is only given when there is intraoperative vascular compromise, as it may cause a hematoma or other bleeding problems. We occasionally use brachial plexus blockade, which has been shown to prevent vessel spasm and to provide early pain relief in related patients [105].
No splints are used; rather, the proximal portion of the palm and wrist is gently wrapped with the fingers uncovered for continuous observation. The hand and forearm are kept slightly elevated atop a smooth support to reduce edema formation. The dressing is kept simple and light; bulky dressings are not recommended because blood clots may be retained around the wounds, and when the dressing is removed, disruption of the clots may risk induction of vasospasm. Lastly, bulky dressings make it impossible to start early postoperative rehabilitation.
In Chang Gung Memorial Hospital, every free flap patient, such as great- and second-toe transfers, is hospitalized for an average of 5 days in specially designed microsurgery intensive care unit, where trained nurses closely monitor the transplanted toe and the patient’s general condition. The toe is monitored hourly by the nursing staff, and when there is any change from the base line, the attending surgeon is notified.
Toe flap monitoring is done clinically by skin color, turgor, and capillary refill observation every hour by experienced nurse. When in doubt, the pulp of the toe can be pricked with 25-gauge needle. Also, we objectively monitor the toe by measurement of the surface temperature in the toe in comparison to the adjacent normal finger and opposite hand. Also, the Doppler ultrasound and laser Doppler are used for evaluation and assessment [106]. Of these monitoring techniques, the laser Doppler has the highest sensitivity and specificity compared to digital thermometry and ultrasonic Doppler [107].
The donor foot is gently covered with nitrofurazone (Furacin)-impregnated gauze over the wound and a light fluff dressing. No splints are used on the donor foot. Two days later the foot is uncovered, and no further dressings are used.
Rehabilitation
Motor Rehabilitation
The rehabilitation program developed in our unit consists of five stages starting on the first postoperative day [108]:
1.
Protective stage (days 1–3). During this stage, interaction between the patient and the hand therapist is established.
2.
Early mobilization stage (day 4 to week 4). Rehabilitation is directed at preventing excessive swelling and joint stiffness. We start with 15-degree gentle passive range of motion exercises. In the second week, the joint distal to the bony union site is moved through a full range of motion while keeping the wrist in neutral position. In the third and fourth weeks, the proximal joints are moved more aggressively, with full range of motion avoided so as not to interfere with bone healing. A protective splint is provided between exercises.
3.
Active motion stage (weeks 5–6). Gentle active exercise is started, and the splint is changed to a dynamic one, if necessary. During the sixth week, blocking flexion and extension exercises are initiated.
4.
Activities of daily living training stage (weeks 7–8). According to patient capabilities, different manual jobs that simulate daily manual activities are assigned.
5.
Prevocational training stage (week 8 and beyond). This training aims to further improve muscle strength and hand dexterity and coordination.
Sensory Rehabilitation
Sensory recovery is important for functional recovery [49, 108] and is primarily accomplished by reeducation, which is directed at helping the patient interpret the altered sensory impulses reaching the brain from peripheral nerves [108, 109].
The program of sensory reeducation is divided into early and delayed stages. In the early stage, reeducation focuses on facilitating the perception of touch submodalities with correct localization and continues according to a sequence of sensory recovery reported by Dellon [109]. Late-phase sensory reeducation focuses on size and shape discrimination and object identification. In a study of sensory recovery after toe-to-hand transplantation, the senior author and his colleagues found a good relationship between Meissner corpuscle number and two-point discrimination.
Donor Site Rehabilitation
For the first 2 weeks following toe harvest, the patient should remain non-weight-bearing on the donor foot. The patient is allowed to walk a few steps on the heel of the donor foot after the second week. It must be emphasized that any contact with the anterior plantar weight-bearing surface should be avoided during this recovery period. The sutures in the donor foot should not be removed earlier than 3 weeks following the operation. After 4 weeks, the patient is allowed to walk with a normal gait.
Outcome
Yam and Wei et al. reported on 96.8 % survival rate in 31 primary transfers vs. 96.5 % in 144 secondary transplantations [56]. There was no statistical difference between the two groups in terms of survival, intraoperative anastomotic revision, re-exploration, future secondary procedure, infection, and complications [56]. Rosson and Buncke compared outcomes between thumb replantation and great-toe transplantation, when the thumb proved non-replantable, for isolated amputations of the thumb and reported higher success rate in transplantation group (93 % vs. 85 %) [54]. Woo et al. and Ray et al. reported in multiple series on immediate partial great-toe transfer with a 100 % success rate [26, 59, 60]. Together, all these reports lay a strong foundation for the safety and reliability of primary toe-transplantation surgery for the management of fresh digit amputations.
Another measure of outcome is objective measurement of hand function. Long-term follow-up of successful immediate partial great-toe transfer showed that mean static two-point discrimination was 8.2 ± 1.2 mm, key pinch was 66 % of the intact contralateral side, and grip power was 57 ± 17.4 % (range, 30–85 %) of the contralateral hand [26]. Huang et al. showed that the mean static two-point discrimination in partial great-toe transfer and second-toe transfer groups was 7.8 ± 1.3 mm and 7.6 ± 1.2 mm, respectively. The grip strength was 78 ± 6.3 % the normal contralateral hand in partial hallux transfer vs. 68 ± 9.7 % in second-toe transfer group [110]. Rosson and Buncke’s [54] study mentioned previously noted that the IP joint motion was greater in hallux transplantation group compared with replantation after crush/avulsion injury but was the same between both after sharp cut amputations. Total MCP motion and grip and pinch strength were essentially the same between the two groups.
Data demonstrating that the transplanted toe has better sensation than both the donor toe and the replanted thumb [49, 100] suggests that the great-toe transplantation maybe functionally better than thumb replantation in crush/avulsion injury and as good as thumb replant in sharp cut amputation [54].
The best measurement of outcome is the use and function of the hand. With regard to this, there is only one well-designed study over long-term follow-up (range 3–13 years) [55]. In this study, Wei and Cheng showed that toe transfer patients had statistically significantly better overall hand function, work performance, aesthetics, and satisfaction. Functional testing demonstrated that strength and dexterity of the toe transfer hands were comparable to the opposite normal hands.
Complications
The most dreadful complication is free toe transfer failure; however, primary toe transplantation has a very high survival rate (range 93–100) [26, 45, 54, 59, 60, 110]. Failed toe transfer tends to happen in more frequently in transferred great toes compared with second-toe transplantation and in crush/avulsion compared to sharp injury [45, 54]. Notably, timing of transfer does not play any adverse effect on transplant survival [45]. There is no statistical difference in re-exploration rate between primary and secondary toe transfer. Risks of arterial or venous compromise can be minimized by maintaining meticulous hemostasis during the surgery, tension-free closure, and wide subcutaneous tunnels for the vessels. When perfusion is in doubt during the primary procedure, second artery should be utilized as a life boat [26, 45, 59, 60, 105, 110]. Vasospasm may complicate toe transfers just as it may threaten replanted digits; risk reduction for this and management are discussed elsewhere in this book (Chap. 8).
Conclusion
Toe transfer for restoration of finger or thumb function has a well-established role in settings where replantation is either impossible or has previously failed. Outcomes from both functional and aesthetic standpoints are good and compare favorably to primary replants. The mechanics of performing toe-to-hand transfer are essentially the same as those involved in replantation surgery and should come naturally to the experienced hand surgeon. The potential need for a toe transfer should guide management of the recipient hand during the initial surgery at the time of injury so that no reconstructive bridges are burned at the primary treatment. The techniques described above combined with a motivated patient may convert an otherwise “assist” hand to one with functional grasp and pinch.
References
2.
Waljee JF, Chung KC. Toe-to-hand transfer: evolving indications and relevant outcomes. J Hand Surg Am. 2013;38(7):1431–4.PubMedCentralPubMed
3.
Matsuzaki H, Narisawa H, Miwa H, Toishi S. Predicting functional recovery and return to work after mutilating hand injuries: usefulness of Campbell’s Hand Injury Severity Score. J Hand Surg Am. 2009;34(5):880–5.PubMed
4.
Dzwierzynski WW. Replantation and revascularization. In: Neligan PC, Chang J, editors. Plastic surgery. 3rd ed. Philadelphia: Elsevier Saunders Publishing; 2013.
Related posts:
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
