The requisites of a satisfactory stump include:
1. Adequate length.
2. Sufficient soft tissue cover.
3. Sensibility.
Surgical technique
1. Skin flaps of sufficient size are raised to expose the underlying bone, flexor and extensor ten-dons, and neurovascular bundles.
2. If the amputation is through an IP joint, the articular cartilage is not removed, but the condyles and any rough projections of bone are nibbled away.
3. Flexor and extensor tendons are cut so that they lie away from the stump. If they are sutured over the stump, they will interfere with the movements of the other fingers.
4. Digital nerves are dissected and cleanly divided about 1 cm proximal to the stump, so that any neuroma that forms is not at the scar line.
5. Skin is closed accurately and a non-adherent compression bandage is applied.
6. The wrist and digit are splinted in elevation for at least 48 h.
Possible complications 1. Poor skin cover.
2. Poor circulation.
3. Neuroma formation.
4. Stiff joints of the injured or adjacent digits.
5. Inadequate length for function.
6. Phantom pain (Jensen et al., 1985).
7. Dystrophy.
Postoperative therapy of digital amputations
The aim of treatment is to regain movement and function as quickly as possible. This is accom-plished by a combination of passive and active exercise and desensitization techniques. Early function is also encouraged (Fig. 13.7).
The hand is rested in a light plaster and kept elevated for the first few postoperative days. Three days after surgery, gentle active stabilized flexion/
extension exercises are begun. Full range of movement is maintained at all upper limb joints.
Stump dressings should be minimal so that IP joint motion can be performed without the restriction of a too-bulky dressing. Coban wrap (25 mm) is used to hold the dressing in place, to treat pulp oedema and to help shape the stump (Fig. 13.8).
Figure 13.6. Opsite Flexifix applied to this skin-grafted middle finger tip significantly reduced hypersensitivity and allowed the patient to use the digit.
The hand should be used for light self-care activities as soon as possible. Early use of the hand improves mobility, assists with the desensitization process and has a positive psychological effect.
Sutures are usually removed between 10 and 14 days at which time warm water soaks (containing a mild cleansing agent) are carried out several times a day. These will assist with wound debridement and help facilitate movement if stiffness is still a problem. Light sponge squeezing in the water will also promote movement and help with
desensitiza-tion. Light massage with cream or oil will soften the scar and plays an important part in the desensitization process (Fig. 13.9).
Opsite Flexifix is applied to the stump to reduce sensitivity at this early stage (Boscheinen-Morrin and Shannon, 2000). Patients generally find their desensitization exercises much easier to perform through the Opsite layer. They are also more inclined to use the stump during activity when the film is in place (Fig. 13.10). Coban wrap or silicone-lined fingerstalls can be used in conjunc-tion with the Opsite for scar management and stump shaping (Fig. 13.11).
In preparation for return to work, patients are encouraged to use the hand for normal domestic and house maintenance activities. Carrying light shopping bags, hanging out washing, window Figure 13.7. Following amputation, early function is
encouraged.
Figure 13.8. Coban wrap (25 mm) is used to hold the dressing in place, reduce pulp oedema and shape the stump.
Figure 13.9. Oil or cream massage softens the scar line and is an important part of the desensitization process.
Figure 13.10. Opsite Flexifix applied to the stump significantly alleviates hypersensitivity. This makes desensitization exercises easier and encourages early function. The area of application is highlighted.
180 The Hand: Fundamentals of Therapy
washing, etc., will all help encourage normal use of the hand and entire upper limb. Attempting to use equipment such as vacuum cleaners or lawn mowers for short periods will help acclimatize the hand to vibration. Gardening activities will promote gross gripping and general fitness.
Most patients are able to resume manual work within 4 to 6 weeks after amputation.
Reconstruction
Where replantation was not possible, reconstruc-tive procedures can be considered. The patient’s suitability is assessed in terms of age, occupation, leisure pursuits and hobbies, hand dominance, general health and the psychological ability to cope with sometimes numerous surgical procedures and aftercare programmes.
Reconstruction is most often used for restoration of pinch grip function. This can involve rearrange-ment of hand remnants or reconstruction of the thumb itself.
Local rearrangement of hand remnants 1. Deepening of the interdigital cleft, e.g. the
thumb web, by Z-plasty lengthening of the skin and sliding the thenar muscle attachments down the shaft of the first metacarpal (Fig. 13.12).
2. Transfer of a digit, i.e. pollicization, when the metacarpal of the donor digit (e.g. index finger) is divided and transferred to the recipient stump; internal fixation is used to stabilize the transferred digit.
Toe to thumb reconstruction
Complete or partial toe transfer has proved effec-tive in reconstructing the absent or deficient thumb. The toe has strong skeletal support, a nail, glabrous skin that can be reinnervated and mobile joints. Problems of size discrepancy (the large toe is about 20 per cent larger than the thumb) have been partly addressed with the ‘wraparound’ and
‘trimmed toe’ procedures.
While toe transplantation has the disadvantage of toe loss, the transplanted toe mimics the structure and function of a thumb more closely than any other thumb reconstruction procedure.
The five toe transplant options for thumb reconstruction include:
1. Whole great toe transfer (Fig. 13.13).
2. Second toe transfer.
3. The ‘wraparound’ procedure (Morrison et al., 1980) – this procedure is suitable for thumb loss distal to the MCP joint and involves transfer of a soft tissue flap and nail from the great toe;
bony support is supplied by an iliac bone graft rather than the phalanges of the great toe. This transfer does not provide motion.
4. The ‘trimmed toe’ technique – the great toe is trimmed to the dimensions of the opposite thumb. Like the ‘wraparound’ technique, this procedure is used primarily for thumb loss distal to the MCP joint. Unlike the ‘wrap-around’ technique, this procedure does provide motion.
5. Partial toe transplant.
Figure 13.11. Silicone-lined mesh fingerstalls can be used over the Opsite film where hypersensitivity is severe or where scar management is still indicated.
Figure 13.12. This 18-year-old apprentice carpenter was left with a ‘mitten’ hand following a circular saw injury at work. The re-creation of a thumb web restored gross grasp and enabled him to complete his apprenticeship.
Sensation in the new thumb is anticipated in approximately 4 to 6 months.
Distraction lengthening of the
metacarpals and phalanges (callotasis) Distraction lengthening is a means of restoring functional length to a hand that is skeletally deficient through trauma or congenital absence (Seitz, 1999). This technique was first used for elongation of the long bones in the lower limbs.
Although this procedure improves hand cosmesis, its primary goal is to enhance mechanical advan-tage and thereby function. This procedure requires high patient compliance; patient selection is there-fore crucial.
Distraction lengthening can be applied to the thumb or multiple digital rays. A midshaft osteot-omy is made through the metacarpals or phalanges and the distraction device is applied. The lengthen-ing process begins on the 5th postoperative day for children and the 7th postoperative day in the case of adults. The process involves four daily incre-ments of 0.25 mm each. About 2–2.5 cm of lengthening can be obtained through remodelling of the fracture callus. Following the lengthening period, the device needs to be worn for an
additional period to allow complete bony con-solidation. The extended period needs to be 2 to 3 times the duration of the lengthening period and the device is not removed until there is radiological evidence of consolidation of at least three cortices.