Toe-to-hand transfers in children

Microsurgical reconstruction of congenital upper extremity deformities of malformations

We present two rare microsurgical reconstructions. A case with phocomelia was treated with lengthening of soft tissues following vascularized fibula grafting with epiphysis, and a case with cleft hand was reconstructed with spare-part toe transfer.

Thumb Amputations in Children: Classification and Reconstruction by Microsurgical Toe Transfers

PURPOSE

Traumatic amputations of the thumb are rare in children compared with adults, but hand surgeons remain reticent to consider microsurgical reconstruction with toe-to-thumb transfers. This study reports the functional outcomes and complications of children with traumatic thumb amputations who underwent toe-to-thumb reconstruction.

METHODS

A retrospective review of children who sustained thumb amputations and whose parents elected for their child to undergo reconstruction by toe-to-thumb transfer was performed. Details of the level of thumb amputation, whether other fingers were also amputated, which toe was transferred on which vascular pedicle, survival of the transfer, and complications, were collected. Opposition, sensation, and growth of the toe-to-thumb transfers was measured. Functional and psychosocial outcomes were evaluated by both the parents and the older children using the Pediatric Outcomes Data Collection Instrument questionnaire.

RESULTS

Twenty-one thumb amputations in 19 children between the ages of 2 and 17 years were referred for secondary reconstruction. Ten were isolated thumb amputations and 11 were combined thumb and multiple finger amputations. Two children had bilateral thumb amputations. Twenty-one toe-to-thumb transfers were performed: 14 second toe transfers and 7 great toe transfers (3 great toe and 2 trimmed and 2 Morrison wraparound variations). There were no immediate postoperative reexplorations of the microsurgical anastomoses and all toe transfers survived completely. All children regained pinch and grasp function and sensation. There were no gait problems in the donor feet.

CONCLUSIONS

Microsurgical toe-to-thumb transfers should be offered as an alternative option to the traditional techniques of distraction lengthening and pollicization, for posttraumatic thumb reconstruction in children for any level of amputation from just distal to the carpometacarpal joint to the interphalangeal joint. Toe-to-thumb transfer provides length, opposition, and sensation without disturbing ambulation and is associated with excellent psychosocial outcomes as evaluated by both parents and older children.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Paediatric toe-to-hand transfer: an assessment of outcomes from a single unit

Toe-to-hand transfer is an acceptable treatment option for children born with absent digits. Toe transfer can provide functionally useful digits and may enhance patient wellbeing. A total of 19 children had 31 free second-toe-to-hand microsurgical transfers between 1998 and 2012. The mean age of these children at the time of the first operation was 45 months. All transferred toes survived. The donor site was satisfactory in all 19 patients. Twelve children (19 toes) attended a special review clinic; all children could grasp large objects (Duplo bricks) after toe transfer. The total passive range of motion was greater than total active range of motion by an average of 54 degrees. Static 2-point discrimination was generally excellent (mean = 5 mm). Eleven out of 12 children strongly agreed that their toe transfer had improved hand function. Microsurgical toe-to-hand transfer is a safe and reliable technique that can provide useful function for children with congenital differences. Our series compares favourably with the published literature.

LEVEL OF EVIDENCE

IV.

Indications for microsurgical reconstruction of congenital hand anomalies by toe-to-hand transfers

BACKGROUND

The indications for microsurgical toe-to-hand transfers in congenital hand surgery have not been defined as clearly as for posttraumatic reconstruction of thumb and finger amputations. The purpose of this study was to develop simple guidelines for referral of children with congenital absent digits for consideration of microsurgical reconstruction with toe-to-hand transfers, based on the morphological or radiographic anatomy of the hand anomaly, not on embryological classifications.

METHODS

From a consecutive series of 204 children referred with congenital absence of the thumb and fingers, 100 toe-to-hand transfers were performed. The indications for microsurgical reconstruction of these children were analyzed retrospectively.

RESULTS

Forty-one thumbs were reconstructed in 38 children-15 children with an absent thumb distal to the metacarpal base but with four relatively normal fingers; 12 children with an absent thumb and only one or two digits remaining on the ulnar side of the hand; and 11 children with complete absence of all five digits. Twenty-nine second toes and 12 great toes were transferred to reconstruct congenital absent thumbs. Fifty-nine fingers in 52 children were reconstructed mostly with single second toe transfers-41 children with a thumb but absence of all four fingers and 11 children with absence of all five digits.

CONCLUSIONS

The morphological or radiographic anatomy of a child's hand with congenital absent digits is a more logical indication for microsurgical reconstruction than any embryological classification. The three most common indications for toe transfers for reconstruction of congenital absent thumbs are (1) absent thumb distal to the carpometacarpal joint with four relatively normal fingers, (2) absent thumb with only one or two fingers remaining on the ulnar border of the hand, and (3) complete absence of the thumb and all four fingers. The two indications for toe transfers for reconstruction of congenital absent fingers are (1) absence of all four fingers but with a normal thumb remaining and (2) complete absence of all five digits.

TOE-TO-HAND TRANSFER IN SYMBRACHYDACTYLY

Symbrachydactyly, or central atypical cleft, is classified as a failure of formation. For the adactylous or monodactylous forms, free toe transfer is the treatment of choice. We present 18 free toe transfers in 13 patients for symbrachydactyly. Despite abnormal anatomy, the functional building blocks have always been available and transfer technically possible. The result has been improved function and high levels of parental satisfaction.

Undergrowth: brachydactyly

Brachydactyly simply means "short finger", but it has a clinical spectrum ranging from minor digital hypoplasia to complete aplasia. The index and small fingers are the most commonly affected digits, and the middle phalanx is the most commonly affected bone. Presentation of brachydactyly is highly variable-a digit may be just slightly shorter because of reduced growth of one phalanx or the metacarpal, or there may be complete absence of one or more phalanges, or there may be complete aplasia of the digit or multiple digits. This article discusses the results of conventional reconstruction using nonvascularized toe phalangeal bone grafting and distraction lengthening and the newer technique of microsurgical toe-to-hand transfers.

Precision grip function after free toe transfer in children with hypoplastic digits

Although toe-to-hand transfer has a defined role in the management of congenital hand deformities, it remains unclear how well children integrate the transferred digits into physiological grasping. We analysed fingertip forces in the precision grip of 13 patients when lifting a test object more than three years after free toe transfer for absent or hypoplastic digits. Clinically, most patients showed normal sensibility of transferred digits, but active motion and pinch strength were limited as compared to the normal hand. For the control of fingertip forces, two key features of the normal two-digit opposition grip were seen in all operated hands: adaptation of grip force to object weight and parallel coordination of lift and grip forces. These physiological grasping strategies developed independently of the patients' age at the time of operation, which ranged from one to 13 years. In four patients, we observed increased tangential load forces with the operated hand due to misalignments in the application of fingertips on the grasp surfaces. Such forces lead to increased grip force requirements on both fingers that may overload transferred digits with limited motor function. The need for optimal alignment of the grip axis during toe-transfer surgery is emphasised.

Temporary arteriovenous loop between the saphenous vein and the first plantar metatarsal artery in toe-to-hand transfers

We describe a technique for creating a temporary arteriovenous loop by anastomosing the saphenous vein to the first plantar metatarsal artery to facilitate harvesting and subsequent anastomosis of a great or second toe transfer. This technique has been used in 9 patients: 6 pediatric toe-to-hand transfers for congenital hand differences and 3 adult toe transfers for a thumb amputation. All 9 toe transfers survived. The advantages of this technique are that it allows precise determination of the exact length of the loop to reach the recipient artery, it facilitates palmar positioning of the arterial pedicle, and, if necessary, the saphenous vein can be anastomosed directly to the lateral digital artery of a great toe transfer or the medial digital artery of a second toe transfer rather than the first plantar metatarsal artery itself, thereby minimizing more proximal dissection of the first plantar metatarsal artery, which is more difficult and time consuming.

Restoration of functional prehension after radial hemihand amputation in a three-year-old child: rationale for and long-term result after great toe transfer

Partial hand amputations are rare injuries among children, causing significant functional impairment. Reports on thumb reconstruction in children and adults are used to develop a reconstruction plan for restoring prehension. While either first or second toe transplantation may be indicated to restore prehension in adults with thumb loss, near universal reluctance to use the great toe in children centers around concern regarding the subsequent function and appearance of the foot. This report details the reconstruction of functional prehension after radial hemihand amputation in a 3-year-old child. Great toe transplantation was used and resulted in neither objective nor subjective donor site morbidity. The rationale for use of the great toe in this child and long-term functional outcome are described.