Abstract
Soft tissue injuries to the arm, and or fingers must be addressed in a timely fashion with a goal toward restoring the injured part with the highest quality tissue. Failure to do so will often result in a stiff joint, unstable scar, and/or dysfunction of the extremity. Thus, the principle of “replace like with like” is often invoked. This chapter has been constructed to educate and illustrate the reconstructive options available to the surgeon who is treating soft tissue injuries of the hand and upper extremity.
19 Soft Tissue Reconstruction: Hand and Upper Extremity
I. Introduction
Upper extremity injury can involve bone, tendon, nerve, vessels, soft tissue, and skin.
The reconstruction should ideally “replace like with like.”
Soft tissue coverage options should consider donor site morbidity.
Optimize wound healing and functional outcomes with the following principles:
Catalog all injured structures requiring repair.
Debride back to healthy tissues (may require multiple debridements)
Delay bone, tendon, and nerve repair/reconstruction until the time of definitive soft tissue coverage.
Provide stable bone fixation and strong tendon repairs to allow for early motion.
Resurface wounds with healthy soft tissue coverage that is supple and minimizes dead space.
Delay reconstruction in the face of life-threating injuries; temporary coverage with allograft or xenograft or managing open wounds with a negative pressure dressing can allow for time between injury and formal reconstruction.
A multidisciplinary team approach will allow comprehensive care: Upper extremity surgeon, physical and occupational therapy, and psychologist or psychiatrist.
Sometimes amputation is functionally the best treatment:
If the expected result is a stiff or insensate part.
If the injured part impairs the global function of the arm or hand.
If the part is grossly contaminated, has segmental injuries, and/or cannot be salvaged.
Evaluate patient’s comorbid conditions and overall health:
History of cardiac disease, pulmonary disease, bleeding, or thrombophilic disorder can affect reconstruction options.
Occupation matters: A manual laborer requiring strength may benefit from a different reconstruction than a musician requiring dexterity.
For severe crushing, mangling injury, defer final reconstruction for at least 24 to 48 hours after the injury.
To allow for complete demarcation of tissues.
To allow for adequate debridement.
Ischemia and inadequate resuscitation can extend the zone of tissue necrosis:
Muscle, skin, and then bone have increasing tolerances to ischemia—muscle can survive for 4 to 6 hours.
Whenever possible, select the soft tissue reconstruction that can deliver the prerequisites of a dexterous extremity:
Supple skin.
Sensation.
Muscle tendon glide/continuity.
Posture and position allowing interaction with the environment, hygiene, and avoidance of trauma.
Address postoperative access to therapy, clinic visits, medical needs, and psychologic counseling prior to discharge.
II. Finger
A. Anatomic Considerations
Palmar glabrous skin
Resistant to shear forces due to high coefficient of static friction and papillary ridges (forming individual characteristic fingerprints).
Sensation with discrimination (narrow static and two-point discrimination).
Dorsal nonglabrous skin
Thin, soft, and mobile.
Often hair bearing in males.
Sensation (less discrimination than palmar skin).
B. Distal Coverage
Goal: Sensate glabrous skin where missing or nail elements where missing.
Secondary intention (small fingertip defects):
Wounds of up to 2 cm.
Injuries without exposed bone, nerve, or tendon can be allowed to heal secondarily.
Even small wounds of the distal finger with healthy appearing exposed bone can often heal by secondary intention.
Daily dressing changes:
Keep the wound clean with daily washes or soaks.
Keep the wound moist with an ointment.
The result is often one of good sensation, and contour with no donor site morbidity.
Motion throughout the healing process can help minimize stiffness.
Wounds larger than 2 to 3 cm may benefit from surgical intervention.
Primary closure.
Cap graft:
In a distal fingertip amputation, for children less than 10 years of age, the amputated part may be sutured to the tip as a composite graft, after defatting as a “cap graft”. 1 , 2
Graft take is 7% with a majority of patients experiencing partial graft failure.>
Reoperation rates with cap or composite grafts is 10%. 3
1. Local Flaps
Homodigital flap (► Fig. 19.1):
Neurovascular island flap based on radial or ulnar digital artery.
Can cover tip, pulp, and dorsal wounds.
Can be used based on anterograde or retrograde blood supply:
Anterograde homodigital island flap is immediately sensate. 4
Retrograde homodigital island flap is not immediately sensate.
Given the immediate sensation, an anterograde homodigital island flap is often preferred:
A proximal interphalangeal (PIP) flexion contracture is a commonly cited risk of the flap (but not often a clinical finding or, when present, of clinical significance).
If raised as a retrograde flap, the nerve may either be included or excluded from the flap:
If included, the nerve has to be coapted to the contralateral distal nerve for the prospect of sensation.
Excluding the nerve, although possible, could compromise flap venous drainage.
The anterograde flap is designed by making a template of the wound and transposing the template directly above the distal aspect of the radial or ulnar digital artery (surgeon’s preference).
Harvesting the flap from the ulnar aspect of the digit usually results in less noticeable scar.
The flap can be slightly less than the size of the wound
The flap is raised by preserving all soft tissue attachments between the skin and the neurovascular bundle (like a balloon on a string).
Great care is taken to not over-dissect the pedicle:
The venous drainage of the flap is likely the periadventitial tissues which should be protected by avoiding pedicle skeletonization.
The nerve and artery should be kept together throughout the dissection.
The flap donor site can be managed with a skin graft.
The hand is splinted with the digits in slight flexion for 3 weeks after which time, no splinting is required.
Range of motion exercises are allowed during this period of protection.
Atasoy or volar V-Y advancement flap
Pedicled flaps often used for distal transverse or dorsal oblique fingertip defects
Atasoy (V-Y) should be designed such that the base of the “V” should not cross the distal interphalangeal (DIP) flexion crease: 5
Cuts should be made only to release dermal attachments.
Cuts should not be made full thickness as this will compromise the blood supply of the flap.
These flaps are contraindicated for defects with more volar than dorsal skin loss.
Deep fibrous septa that anchor the glabrous skin to the underlying phalanx can be released with an elevator or knife but the superficial subcutaneous tissue should be retained.
Up to 1 cm advancement is theoretically achievable.
Functional and cosmetic results are excellent with this flap.
There exists a risk of cold intolerance and dysesthesia with this method. 6
Kutler or lateral V-Y advancement flap
Indicated for transverse and lateral oblique fingertip defects.
Flap uses lateral V-Y advancements lateral to the wound.
Elevated similar to the volar V-Y advancement flap in the plane of the neurovascular bundle above the flexor tendon sheath.
Kutler flaps should be designed to preserve the flap’s blood supply from each digital artery:
The dorsal cut can be full thickness to periosteum.
The volar cut should be deep enough to release dermal attachments but should not be made full thickness.
Full-thickness volar cuts would transect the digital arterial blood supply to the digit.
Limited flap mobility allows minimal coverage.
There exists a risk of cold intolerance and dysesthesia. 7
Adipofascial turnover flap (► Fig. 19.2)
Pedicled homodigital flap often used when other methods are unavailable.
The skin is incised and elevated off the underlying fat.
A distal “pedicle” of fat is marked and protected from dissection.
The adipofascial tissue is then incised as a rectangular flap and elevated in a proximal to distal fashion.
The flap is brought distally, flipping it over the pedicle, and sutured in place to cover the defect.
The adipofascial tissue can then be skin grafted.
C. Proximal Coverage
Goal: Coverage of vital structures, preservation of function (by providing gliding planes and sensate tissue), and restoration ofform.
Small wounds can be allowed to heal via secondary intention.
Small wounds amenable to primary closure can be closed after a thorough washout.
Larger wounds that cannot be closed primarily or would take excessive time to heal secondarily should be managed with a flap.
1. Cross Finger Flap
Dorsal skin used as a pedicle flap to resurface volar defects (► Fig. 19.3):
The flap is insensate.
The flap brings nonglabrous skin to a previously glabrous area.
The flap is an example of an interpolated flap.
The flap is outlined on an adjacent finger keeping the pedicle radial for flaps destined to be transferred radial or ulnar for flaps destined to be transferred ulnar.
The skin is elevated off the extensor tendon taking care to preserve the paratenon (to facilitate skin graft take at the donor site).
The flap is inset into the defect and the fingers are effectively (and purposefully) syndactylized.
The flap is often divided at 3 weeks.
Stiffness is an often-cited risk factor especially in patients with advanced age (>50 years), osteoarthritis, or both.
2. Reverse Cross Finger Flap
Dorsal adipofascial tissue used to resurface dorsal wounds:
The flap is insensate.
The flap does not have skin and, as such, requires a skin graft.
The flap is raised from an adjacent finger with an incision made on the side of the finger toward the defect (the incision should be ulnar for a defect on an ulnar digit and radial for a defect on a radial digit).
A skin flap is then elevated in the immediate sub-dermal plane taking care to protect the adipofascial tissue beneath.
The adipofascial tissue is raised as a pedicle flap by raising it off the extensor tendon.
The paratenon needs not be protected here as the tendon will be covered by the overlying skin upon closure.
The flap is flipped over on itself and inset into the defect effectively (and purposefully) syndactylizing the digit.
A split or full-thickness skin graft is applied to the flap.
The elevated skin on the donor finger is closed over the extensor tendon taking care not to kink or apply pressure to the adipofascial flap pedicle.
The flap is divided at 3 weeks.
Motion is initiated once the skin graft appears adherent.
Mobilization is immediate.