A 30-year-old man presents after having suffered an explosion trauma to his left hand a few months ago. The initial treatment consisted of wound debridement and partial closure of the wound. The remaining wound healed on secondary intention.
Despite the acute trauma surgery treatment in the local emergency department and postoperative rehabilitation, the explosion trauma resulted in a massive deformity of the left thumb and a contracture of the first web space between the thumb and the index finger.
Furthermore, the patient complained about neuroma pain in the digital nerves III and IV as well as pain in the remaining distal part of the index finger resulting from inappropriate soft-tissue coverage (▶Fig. 32.1).
The patient showed with a severe skin and soft-tissue contracture of the first web space (so-called web-space syndactyly) and concomitant injuries including adduction deformity of the thumb, limitation of the thumb extension and opposition function, and carpometacarpal contracture. Being the only opposing digit against the others, the thumb has a major contribution to the overall hand function. When the thumb is involved, functional loss of the whole hand is severe. Therefore, the correction of the thumb’s deformity constitutes the most important part for a beneficial functional outcome. Adequate length, mobility, stability, and sensation are the goals of a functional thumb reconstruction.
Fig. 32.1 Preoperative view of the hand showing severe deformity of the thumb in the interphalangeal and base joint 4 months after trauma.
One should notice that it is very important for a successful outcome after burn or explosion injury that early measures, such as early debridement, edema and infection control, early wound coverage, and early mobilization, be performed. With these simple principles applied correctly, the most difficult postburn complications such as flexion contracture and finger deformities can be minimized or even prevented.
Superficial burns usually heal spontaneously within 10 days. Full-thickness wounds would only heal slowly on secondary intention and would result in restricted function and mobility because of scar tissue formation. On the other hand, the early motion that is required to prevent joint stiffness and reduce edema formation may inhibit the healing process. Deeper wounds would take more than 2 weeks to heal on their own; therefore, these should be treated by excision and coverage with a graft or flap. Placement of full- or split-thickness skin grafts has been used successfully in treating both superficial and partial-thickness burns of the hand.
In cases of full-thickness burns, after excision and debridement, exposed deeper structures (i.e., free-lying tendons) rarely accept skin grafts and therefore require flap coverage.
Flap coverage is an excellent option in injuries of the hand because of the ability to cover the wound while providing a smooth surface for joint and tendon motion and the potential for early mobilization with hand rehabilitation therapy.
When early adequate treatment is lacking, contractures and deformities such as seen in our patient, appear. In order to achieve a better functional outcome, secondary surgical revision and correction is needed.
Mild to moderate contractures involving the thumb and adjacent web-space area can be corrected simply by contracture release combined with the basic reconstructive techniques including skin grafting, variations of Z-plasty flaps, and Y-V advancement techniques.
A severe contracture that causes a major deformity like the one seen in our case, however, requires a more complex procedure such as local or regional flaps for soft-tissue defect coverage.
In our case, we chose a distally based radial forearm flap as it presents an optimal solution for defect coverage.
• Explosive trauma often causes severe contractures.
• Severe contractures leading to massive deformity of the thumb and great functional loss of the hand require secondary revision and scar contracture release.
• Defect coverage after release of severe contractures as shown in our case requires a more complex procedure. A distally based reverse radial forearm flap is an ideal option for defect coverage.
Prior to the operative intervention, before deciding to use a radial forearm flap, an Allen test was performed to ensure that retrograde flow through the ulnar artery would maintain blood flow to the hand.
The patient was then taken to the operating theater. The surgery was performed under general anesthesia. The arm was exsanguinated and a tourniquet was raised to 250 mm Hg.
At first, the patient was treated with a subtotal palmar and digital scar contracture release on the left hand. The neurovascular bundles were identified and protected. Tenolysis of the flexor pollicis longus tendon was then performed.
At the conclusion of the procedures, complete correction was obtained at both the metacarpophalangeal and interphalangeal (IP) joints of the thumb. Contracture release in the first web space allowed a free abduction of the thumb.
The new sculptured thumb was then stabilized by means of K-wire in a proper position to achieve a maximum surface for defect coverage.
The next step included further exploration and neurolysis of the digital nerves I to IV and of the median nerve. The painful neuroma of the digital nerve IV was identified and removed, followed by a nerve reconstruction by transplantation of a sensory nerve graft harvested from the left forearm (nerve cutaneous lateralis).
After scar contracture was completely released, soft-tissue defect on the left hand was repaired by incorporating the fasciocutaneous distally pedicled reverse radial forearm flap of the same size as the defect (3 × 8 cm). The flap included the radial artery and an accompanying vein (▶Fig. 32.2). As the tourniquet was deflated, excellent capillary refill in the skin paddle of the flap was noted immediately.
The flap was then placed and secured into position and the donor site was partially closed by undermining the soft tissue medially and laterally to allow tension-free approximation of the wound edges. The area on the donor site that was unable to be closed primarily required a split-thickness skin graft (harvested from the left thigh).
The surgery was completed by removal of the remaining distal phalanx of the left index finger, followed by stump coverage with an advancement flap and removal of the remaining explosive particles out of the left hand (▶Fig. 32.3).
1. An Allen test has to be performed prior to the surgical intervention to ensure adequate retrograde blood supply to the hand through the ulnar artery.
2. Scar contracture release allowed free range of motion of the thumb.
3. Soft-tissue defect coverage was done with the fasciocutaneous distally based reverse radial forearm flap.
4. Donor site closure partially requires a split-thickness skin graft harvested from the left thigh.
The surgical intervention and the patient’s postoperative inpatient stay were uneventful (▶Fig. 32.4).
A rehabilitation regime with a certified hand therapist, consisting of active, active-assisted, and passive range-of-motion exercises was initiated on the second day after surgery. After K-wire removal on the fourth day after surgery, the patient was given a more intense physical therapy, with increasing active, active-assisted, and passive range-of-motion exercises in the IP and base joint of the thumb, fingers, and wrist. To reduce postoperative edema in the flap, lymphatic treatment was initiated.
Wound healing during inpatient stay was uneventful. Daily dressing changes of the hand followed for the next 2 weeks after surgery. The dressing on the forearm donor site was left on for 1 week to promote healing of the skin graft.