Sensory reinnervation in microsurgical reconstruction of the heel

Six sensory reinnervation techniques were carried out in 10 patients who underwent reconstruction of the weight-bearing surface of the heel by microsurgical free-tissue transfer. The techniques include the use of neurovascular island flaps, neurosensory flaps, sensory nerve grafts to skin flaps, coaptation of the sensory nerve to the motor nerve of the muscle flaps, direct sensory nerve transfer, and sensory nerve graft transfer. In all patients, some sensation developed, characterized by sensation to light touch, to dull objects, to pinprick, to pain, and to tickling. Three patients developed the ability to distinguish sharp from dull objects and the sensation of pain. The remaining seven had the sensation of touch to various mechanical stimuli. In nine patients, the sensation is located in the weight-bearing surface of the reconstructed heel. Five patients bear weight on the reconstructed surface at least 6 hours per day. Three participate actively in sports. Split-thickness skin graft-muscle flaps were more prone to breakdown than skin flaps. Full-thickness skin flaps appear necessary for the production of pain sensation and the more discriminating sensations. Preliminary results suggest a functional benefit after sensory reinnervation.     

Sensory restoration of the skin graft on a free muscle flap: experimental rabbit study.

Transplantation of a muscle flap with free skin graft for wound coverage is a common procedure in reconstructive microsurgery. However, the grafted skin has little or no sensation. Restoration of the sensibility of the grafted skin on the transferred muscle is critically important, especially in palmar hand, plantar foot, heel, and oral cavity reconstruction. The purpose of this study was to investigate the possibility of sensory restoration of the grafted skin on a trimmed muscle surface that has been sensory neurotized after sensory nerve-to-motor nerve transfer, using the rabbit gracilis muscle as an animal model. The ipsilateral saphenous nerve (sensory) was transferred to the motor nerve of the gracilis muscle for sensory neurotization. A 4 x 4-cm2 area of skin island over the midportion of the gracilis muscle was harvested as a full-thickness skin graft. The upper half of the gracilis muscle was then excised, becoming a rough surface. The harvested skin was reapplied on the trimmed rough surface of the muscle. After 6 months, retrograde and antegrade horseradish peroxidase labeling studies were performed through skin and muscle injection. The group with a free skin graft was compared with the group with an intact surface of the gracilis muscle. This study clearly shows that sensory nerves can regenerate and penetrate into the trimmed muscle surface and grow into the overlying grafted skin. However, if the muscle surface is intact as with the compared group, sensory reinnervation of the grafted skin is not possible.     

Fasciocutaneous island flap based on the medial plantar artery: clinical applications for leg, ankle, and forefoot

Soft-tissue deficits over the plantar forefoot, plantar heel, tendo calcaneus, and lower leg are often impossible to cover with a simple skin graft. The previously developed medial plantar fasciocutaneous island flap has been adapted to cover soft-tissue defects over these areas. This fasciocutaneous flap based on the medial plantar neurovascular bundle is capable of providing sensate and structurally similar local tissue. Application of this fasciocutaneous island flap is demonstrated in 12 clinical cases. Successful soft-tissue cover was achieved on the plantar calcaneus (four patients), tendo calcaneus (four patients), lower leg (two patients), and plantar forefoot (two patients). Follow-up ranged from 6 months to 5 years. All flaps were viable at follow-up. Protective sensation was present in 11 of 12 flaps evaluated at 6 months. In addition, all 11 patients were able to ambulate in normal footwear. The medial plantar island flap seems to be more durable than a skin graft, and the donor site on the non-weight-bearing instep is well tolerated. This study demonstrates that the medial plantar fasciocutaneous island flap should be considered as another valuable tool in reconstructive efforts directed at the plantar forefoot, plantar heel, posterior ankle, and lower leg.     

Plasticity of skeletal muscle: regenerating fibers adapt more rapidly than surviving fibers

The properties of mammalian skeletal muscle demonstrate a high degree of structural and functional plasticity as evidenced by their adaptability to an atypical site after cross-transplantation and to atypical innervation after cross-innervation. We tested the hypothesis that, regardless of fiber type, skeletal muscles composed of regenerating fibers adapt more readily than muscles composed of surviving fibers when placed in an atypical site with atypical innervation. Fast muscles of rats were autografted into the site of slow muscles or vice versa with the donor muscle innervated by the motor nerve to the recipient site. Surviving fibers in donor muscles were obtained by grafting with vasculature intact (vascularized muscle graft), and regenerating fibers were obtained by grafting with vasculature severed (free muscle graft). Our hypothesis was supported because 60 days after grafting, transposed muscles with surviving fibers demonstrated only a slight change from the contractile properties and fiber typing of donor muscles, whereas transplanted muscles with regenerating fibers demonstrated almost complete change to those of the muscle formerly in the atypical site.     

Use of a cross-forearm neurocutaneous flap to provide sensation and coverage in hand reconstruction.

A cross-forearm, neurocutaneous flap has been used in certain clinical situations to restore coverage and sensation over hand defects. Based on the superficial branch of the radial nerve, this flap provides a combination of handlike skin and subcutaneous tissue with sensation, which can be transferred. A fascicular neurorrhaphy between the superficial branch of the radial nerve and an appropriate recipient nerve stump has resulted in new epicritic sensation in the reconstructed area.     

Comparison of innervated and noninnervated free flaps in oral reconstruction.

Thirteen patients who had undergone ablative surgery for advanced squamous cell carcinoma in which more than half of the tongue had been resected underwent reconstruction in which the cutaneous nerve of a free flap was anastomosed to the stump of the transected lingual nerve. Eight of the patients underwent reconstruction with an innervated anterolateral thigh flap and five patients underwent reconstruction with an innervated rectus abdominis musculocutaneous flap. Sensory recovery of the flap at least 6 months postoperatively was compared in these 13 patients and in 16 additional patients who received noninnervated versions of the same flaps for the same defect. The degree of sensory recovery of innervated thigh flaps was significantly greater than that of noninnervated ones in all modalities and that of innervated rectus abdominis flaps was also greater than that of noninnervated flaps, except for hot and cold perception. These results indicate that sensory regrowth occurs in most areas through the surgically created pathways. However, results of Semmes-Weinstein testing showed that recovery did not reach the level of protective sensation in either type of innervated flap. Although these findings must be followed by additional objective and functional tests and the need for sensory reeducation should be considered, this simple operative procedure can improve postoperative intraoral function and should be attempted whenever possible after ablative surgery.     

A randomized prospective study of polyglycolic acid conduits for digital nerve reconstruction in humans

This article reports the first randomized prospective multicenter evaluation of a bioabsorbable conduit for nerve repair. The study enrolled 98 subjects with 136 nerve transections in the hand and prospectively randomized the repair to two groups: standard repair, either end-to-end or with a nerve graft, or repair using a polyglycolic acid conduit. Two-point discrimination was measured by a blinded observer at 3, 6, 9, and 12 months after repair. There were 56 nerves repaired in the control group and 46 nerves repaired with a conduit available for follow-up. Three patients had a partial conduit extrusion as a result of loss of the initially crushed skin flap. The overall results showed no significant difference between the two groups as a whole. In the control group, excellent results were obtained in 43 percent of repairs, good results in 43 percent, and poor results in 14 percent. In those nerves repaired with a conduit, excellent results were obtained in 44 percent, good results in 30 percent, and poor results in 26 percent (p = 0.46). When the sensory recovery was examined with regard to length of nerve gap, however, nerves with gaps of 4 mm or less had better sensation when repaired with a conduit; the mean moving two-point discrimination was 3.7 +/- 1.4 mm for polyglycolic acid tube repair and 6.1 +/- 3.3 mm for end-to-end repairs (p = 0.03). All injured nerves with deficits of 8 mm or greater were reconstructed with either a nerve graft or a conduit. This subgroup also demonstrated a significant difference in favor of the polyglycolic acid tube. The mean moving two-point discrimination for the conduit was 6.8 +/- 3.8 mm, with excellent results obtained in 7 of 17 nerves, whereas the mean moving two-point discrimination for the graft repair was 12.9 +/- 2.4 mm, with excellent results obtained in none of the eight nerves (p < 0.001 and p = 0.06, respectively). This investigation demonstrates improved sensation when a conduit repair is used for nerve gaps of 4 mm or less, compared with end-to-end repair of digital nerves. Polyglycolic acid conduit repair also produces results superior to those of a nerve graft for larger nerve gaps and eliminates the donor-site morbidity associated with nerve-graft harvesting.     

The lateral intercostal neurovascular free flap

The lateral intercostal flap is a new neurovascular flap that may be used as a free or island flap. It is based on the lateral cutaneous branch of a single posterior intercostal neurovascular bundle. The donor area of the flap is the anterolateral skin of the abdomen. The flap is large, thin, and has a long pedicle that contains the lateral cutaneous nerve. The donor pedicles of the flap are multiple, and its venous drainage is adequate. The detection and design of this flap were based on information gained from the dissection of 95 intercostal spaces in 40 fresh cadavers. The flap was then applied 12 times in 11 patients. Ten flaps were successful, one flap was partially lost, and one was completely lost. The flap was used as a noninnervated flap to resurface six defects in the neck and one facial defect, and it was used as an innervated flap to cover two hand defects and two heel defects.     

Breast reconstruction using the sensate latissimus dorsi musculocutaneous flap

The authors performed immediate breast reconstruction on four patients using a sensate latissimus dorsi musculocutaneous flap accompanied by neurorrhaphy during the past 6 years. In the neurorrhaphy, the lateral cutaneous branch of the dorsal primary divisions of the seventh thoracic nerve, which controls the sensation of the myocutaneous flap, was anastomosed to the lateral cutaneous branch of the fourth intercostal nerve, which controls the sensation of the breast. The subjects consisted of four patients whose postoperative follow-up period was 14 to 29 months, with an average of 19.3 months. The control subjects consisted of 10 cases with a latissimus dorsi musculocutaneous flap whose sensory nerve had not been reconstructed (postoperative follow-up period, 15 to 49 months; average, 26.9 months). The sensory examination included tests of touch, pain, and temperature. The innervated musculocutaneous flap sensation showed gradual recovery at about 6 months after surgery and reached the value of the normal side after about 1 year. In the control subjects, the recovery was gradual after more than 1 year and reached the value of the normal side in only some of the control subjects. On the basis of these findings, the authors consider the present technique to be useful for the recovery of sensation in immediate breast reconstruction.     

The distally based lesser saphenous venofasciocutaneous flap for ankle and heel reconstruction

Finding an appropriate soft-tissue grafting material to close a wound located over the ankle and heel can be a difficult task. The distally based lesser saphenous venofasciocutaneous flap mobilized from the posterior aspect of the upper leg, used as an island pedicle skin flap, can be useful for this purpose. The vascular supply to the flap is derived from the retrograde perfusion of the accompanying arteries of the lesser saphenous vein. These arteries descend along both sides of the lesser saphenous vein to the distal third of the leg, either terminating or anastomosing with the septocutaneous perforators of the peroneal artery. Between February of 1999 and March of 2001, four variants of this flap were applied in 21 individuals, including 11 fasciocutaneous, five fascial, three sensory, and two fasciomyocutaneous flaps. Skin defects among all patients were combined with bone, joint, and/or tendon exposure. The authors found that the flap was reliable and technically simple to design and execute. This one-stage procedure not only preserves the major arteries and the sural nerve of the injured leg, but it also has proved valuable for covering a weight-bearing heel and filling a deep defect, because it potentially provides protective sensation and a well-vascularized muscle fragment. When conventional local flaps are inadequate, this flap should be considered for its reliability and low associated morbidity.     

Reconstruction of a socket using a retroauricular temporal flap

The reconstruction of a continent socket with a skin graft may be difficult because of varying degrees of contracture. In an effort to solve this problem, a retroauricular temporal flap was successfully transposed in a two-stage procedure. The one-stage transposition of a retroauricular island flap based on a temporal pedicle was a partial failure.     

The radial forearm flap: reconstructive applications and donor-site defects in 35 consecutive patients

Thirty-five consecutive patients treated with the radial forearm flap were reviewed. This flap was used in head and neck reconstruction in 25 patients, soft-tissue cover of an extremity in 9 patients, and as a new technique for penile reconstruction in 1 patient. Osteocutaneous flaps were used for mandibular reconstruction in 13 patients. In 6 patients innervated flaps were used to provide sensation on the dorsum of the hand or on the weight-bearing surface of the foot. There was only one total flap failure and no partial failures. Recipient-site complications were few, with prompt healing and very acceptable appearance. Donor-site complications included partial loss of the skin graft with tendon exposure in 10 patients (33 percent), an unsatisfactory appearance in 5 patients (17 percent), and one case of radial fracture (8 percent). On functional testing, there was no significant loss of strength or joint mobility in the donor extremity in 19/20 patients. The authors recommend measures to reduce donor-site morbidity and conclude that, with an acceptable donor site, this flap is valuable in a variety of reconstructive applications.     

V-Y advancement flaps in the reconstruction of skin defects of the posterior heel and ankle

A V-Y advancement pedicle flap including fascia has been used for reconstruction of soft-tissue defects of the posterior heel and ankle region. This flap has been used to cover 17 defects in 16 patients ranging in age from 4 to 58 years, and results have been good. We limited this application to patients without systemic disease and under 60 years of age and did not apply it to the elderly, debilitated, or systemic vascular damaged patients. There were no complications or loss of overlying skin, with the exception of one superficial tip necrosis of the flap. The results indicate the reliability and usefulness of this procedure in coverage of the posterior heel and ankle regions. It is a relatively quick and simple procedure that is without a free skin graft, and it involves only one stage that adequately corrects the skin defect at the posterior heel and ankle without prolonged splintings and results in negligible deformity of the donor site.     

Responses to amputation of denervated ambystoma limbs containing aneurogenic limb grafts

The developing neural tubes and associated neural crest cells were removed from stage 30 Ambystoma maculatum embryos to obtain larvae with aneurogenic forelimbs. Forelimbs were allowed to develop to late 3 digit or early 4 digit stages. Limbs amputated through the mid radius-ulna regenerated typically in the aneurogenic condition. Experiments were designed to test whether grafts of aneurogenic limb tissues would rescue denervated host limb stumps into a regeneration response. In Experiment 1, aneurogenic limbs were removed at the body wall and grafted under the dorsal skin of the distal end of amputated forelimbs of control, normally innervated limbs of locally collected Ambystoma maculatum or axolotl (Ambystoma mexicanum) larvae. In Experiment 1, at the time of grafting or 1, 2, 3, 4, 5, 7, or 8 days after grafting, aneurogenic limbs were amputated level with the original host stump. At 7 and 8 days, this amputation included removing the host blastema adjacent to the graft. The host limb was denervated either one day after grafting or on the day of graft amputation. These chimeric limbs only infrequently exhibited delayed blastema formation. Thus, not only did the graft not rescue the host, denervated limb, but the aneurogenic limb tissues themselves could not mount a regeneration response. In Experiment 2, the grafted aneurogenic limb was amputated through its mid-stylopodium at 3, 4, 5, 7, or 8 days after grafting. By 7 and 8 days after grafting, the host limb stump exhibited blastema formation even with the graft extending out from under the dorsal skin. The host limb was denervated at the time of graft amputation. When graft limbs of Experiment 2 were amputated and host limbs were denervated on days 3, 4, or 5, host regeneration did not progress and graft regeneration did not occur. But, when graft limbs were amputated on days 7 or 8 with concomitant denervation of the host limb, regeneration of the host continued and graft regeneration occurred. Thus, regeneration of the graft was correlated with acquisition of nerve-independence by the host limb blastema. In Experiment 3, aneurogenic limbs were grafted with minimal injury to the dorsal skin of neurogenic hosts. When neurogenic host limbs were denervated and the aneurogenic limbs were amputated through the radius/ulna, regeneration of the aneurogenic limb occurred if the neurogenic limb host was not amputated, but did not occur if the neurogenic limb host was amputated. Results of Experiment 3 indicate that the inhibition of aneurogenic graft limb regeneration on a denervated host limb is correlated with substantial injury to the host limb. In Experiment 4, aneurogenic forelimbs were amputated through the mid-radius ulna and pieces of either peripheral nerve, muscle, blood vessel, or cartilage were grafted into the distal limb stump or under the body skin immediately adjacent to the limb at the body wall. In most cases, peripheral nerve inhibited regeneration, blood vessel tissue sometimes inhibited, but other tissues had no effect on regeneration. Taken together, the results suggest: (1) Aneurogenic limb tissues do not produce the neurotrophic factor and do not need it for regeneration, and (2) there is a regeneration-inhibiting factor produced by the nerve-dependent limb stump/blastema after denervation that prevents regeneration of aneurogenic limbs.     

Temporoparietal-occipital flap for facial reconstruction

Eight patients with an extensive facial defect of the masseter region were reconstructed with a temporoparietal- occipital rotation flap. This flap is vascularized by both the arteria auricularis posterior and the arteria occipitalis lateralis. These vessels have been sufficient to ensure viability of the entire flap. It is elevated and easily transposed to the masseter region because of the distensibility obtained from the posterior neck. This approach avoided the need for an unsightly skin graft at the site while providing tissue with hair follicles that blend well with the surrounding hair. This large flap offers cosmetic advantages over other techniques for coverage of facial defects in men.     

A new flap design: neural-island flap

This report introduces the "neural-island flap" concept, which represents a consistent and reliable skin flap design supplied only by the intrinsic vasculature of a cutaneous nerve. In this study, the lateral femoral cutaneous nerve was selected as the pedicle of the neural-island flap, and a standard skin flap, which is the territory of the accompanying vessels (i.e., iliac branches of the iliolumbar artery and vein), was elevated on the lower dorsal region of the rats. In a total of 92 Wistar rats, three experiments were performed. In part I (n = 24), the vascular anatomy of the lateral femoral cutaneous nerve was established by the methods of dissection, microangiography, nerve mapping, perfusion with colored latex and India ink, and histologic analysis. In part II (n = 46), the role of the cutaneous nerve in supporting an acutely elevated skin flap was explored by creating five flap groups as follows: group 1, conventional flap (artery, vein, and nerve intact); group 2, neural island flap (only the nerve intact); group 3, neurocutaneous flap (vein and nerve intact); group 4, denervated flap (artery and vein intact); and group 5, skin graft. In part III (n = 22), the role of a preliminary surgical delay procedure to augment the survival of the neural island flap was investigated. Results of the anatomic studies indicated a consistent perineural vasculature by the accompanying iliolumbar artery. Skin flaps survived totally in groups where the artery and vein were intact, whereas mean survival rates for the neural island flap and the neurocutaneous flap were 38.2 +/- 3.1 percent and 44.5 +/- 3.8 percent, respectively (p > 0.05). Results of part III of the experiment demonstrated a significantly higher survival for the delayed neural island flap (94.5 +/- 5.5 percent) compared with the acutely elevated neural island flap (p < 0.05). The perineural and intraneural vessels were found to be greatly dilated after a delay procedure, demonstrated by direct observation, microangiography, histologic analysis, dye injection study, and scanning electron microscopy. On the basis of this promising series of experiments, a clinical technique was developed using the sural neural-island flap. The flap was used to reconstruct lower extremity defects in four cases. A delay procedure was accomplished in the first stage by elevating a fasciocutaneous flap from the midcalf region based on a posterior skin bridge and the sural nerve. After a 2-week delay period, a sural neural-island flap was created based on the nerve and transposed to the defect. Flap survival was complete in all cases, with a satisfactory result. The authors conclude that this report proves for the first time that a robust and reliable skin flap can be created pedicled only by the intrinsic vasculature of a cutaneous nerve, after a proper surgical delay. The so-created neural-island flap design offers two novel advantages: (1) a very narrow pedicle and (2) a pedicle without any restriction to a specific pivot point, in addition to the previously described unique advantages of preservation of a major artery and avoidance of microvascular anastomoses.     

Functional reconstruction using a depressor anguli oris musculocutaneous flap for large lower lip defects, especially for elderly patients

Described here is a new technique to reconstruct large lower lip defects using one or two musculocutaneous island flaps, which includes an innervated depressor anguli oris muscle and has a facial artery in its pedicle. Vermilion is simultaneously reconstructed using a mucosal transposition flap. Three patients who had a total lower lip defect and five patients who had a defect larger than one-half of the lower lip were treated by our procedure. All the flaps survived completely without any signs of vascular stasis. In six patients, sphincter function and sensation appeared within 3 months after surgery. In one patient who needed a total lower lip reconstruction, the depressor anguli oris muscle was atrophic and the motor nerve could not be found. This patient could not regain motion. One other patient complained of a sialorrhea accompanied by sensory loss; however, his sensation improved within 6 months after surgery. All of the reconstructed lower lips were large enough to enable the patient to wear dentures and were of a cosmetically acceptable appearance 1 year after surgery.     

The innervated anterolateral thigh flap: anatomical study and clinical implications

During the past 20 years, the neural anatomy of many flaps has been investigated, although no extensive studies have been reported yet on the anterolateral thigh flap. The goal of this study was to describe the sensory territories of the nerves supplying the anterolateral thigh flap with dissections on fresh cadavers and with local anesthetic injections in living subjects. The sensate anterolateral thigh flap is typically described as innervated by the lateral cutaneous femoral nerve. Two other well-known nerves, the superior perforator nerve and the median perforator nerve, which enter the flap at its medial border, might have a role in anterolateral thigh flap innervation. Twenty-nine anterolateral thigh flaps were elevated in 15 cadavers, and the lateral cutaneous femoral nerve, the superior perforator nerve, and median perforator nerve were dissected. In the injection study, the lateral cutaneous femoral nerve, superior perforator nerve, and median perforator nerve in 16 thighs of eight subjects were sequentially blocked. The resulting sensory deficit from each injection was mapped on the skin and superimposed on the marked anterolateral thigh flap territory. The study shows that the sensate anterolateral thigh flap is basically innervated by all three nerves. The lateral cutaneous femoral nerve was present in 29 of 29 thighs, whereas the superior perforator nerve was present in 25 of 29 and the median perforator nerve in 24 of 29 thighs. Furthermore, in the proximal half of the flap, the lateral cutaneous femoral nerve lies deep, whereas the superior perforator nerve and median perforator nerve lie more superficially. Whereas the lateral cutaneous femoral nerve innervates the entire flap, the superior perforator nerve innervates 25 percent of the flap and the median perforator nerve innervates 60 percent of the flap. Clinically, a small anterolateral thigh flap (7 x 5 cm) can be raised sparing the lateral cutaneous femoral nerve and using only the selective areas innervated by the superior perforator and median perforator nerves. Alternatively, a large anterolateral thigh flap can be raised with this multiple innervation. This can be helpful if one wants to harvest the flap under local anesthesia. Sensate bilobed flaps can be harvested when dual innervated flaps are required.     

Time Course and Characteristics of the Capacity of Sensory Nerves to Reinnervate Skin Territories outside Their Normal Innervation Zones

Factors involved in the outcome of regeneration of the saphenous nerve after a cut or crush lesion were studied in adult rats with electrophysiological recordings of low-threshold mechanoreceptor activity and plasma extravasation of Evans blue after electrical nerve stimulation that activated C fibers.

In the first series of experiments, saphenous and sciatic nerve section was combined with anastomosis of the transected proximal end of the saphenous nerve to the distal end of the cut tibial nerve. Regeneration of saphenous nerve fibers involved in plasma extravasation and low-threshold mechanoreceptor activity in the glabrous skin was observed 13 weeks after nerve anastomosis. Substance P-, calcitonin gene-related peptide-, and protein gene product 9.5 (PGP-9.5)-immunoreactive (IR) thin epidermal and dermal nerve endings, as well as coarse dermal PGP-9.5-IR nerve fibers and Meissner corpuscles and Merkel cell-neurite-like complexes, were observed in the reinnervated glabrous skin at this time.

In a second series of experiments, the time course of the regeneration of saphenous nerve axons to the permanently sciatic-nerve-denervated foot sole was examined. Saphenous-nerve-induced plasma extravasation and low-threshold mechanoreceptor activity in the saphenous nerve were found in the normal saphenous nerve territory 2, 3, 4, and 6 weeks after sciatic nerve cut combined with saphenous nerve crush in the left hindlimb. Saphenous-nerve-induced plasma extravasation was also present in the glabrous skin normally innervated by the sciatic nerve 3, 4, and 6 weeks after the sciatic cut/saphenous crush lesion. However, no low-threshold mechanoreceptor activity was detected in the saphenous nerve when the glabrous skin area was stimulated.

In a third series of experiments, the fate of the expansion of the saphenous nerve territory after saphenous nerve crush was examined when the crushed sciatic nerve had been allowed to regenerate. Nerve fibers involved in plasma extravasation were observed in the glabrous skin of the hindpaw after saphenous nerve, as well as after tibial nerve, C-fiber stimulation 3, 12, and 43 weeks after the saphenous crush/sciatic crush lesion.

Low-threshold mechanoreceptors from the regenerated saphenous nerve, which primarily innervates hairy skin, seem to be functional in the glabrous skin if the axons are guided by the transected tibial nerve by anastomosis. Furthermore, the results indicate that fibers from the regenerating saphenous nerve that have extended into denervated glabrous skin areas can exist even if sciatic nerve axons are allowed to grow back to their original territory.     

Innervated radial thenar flap combined with radial forearm flap transfer for thumb reconstruction

A radial thenar flap combined with radial forearm flap was used for the reconstruction of the ipsilateral thumb in four patients. Vascular supply of the combined flap was based on the radial artery and extending the vascular pedicle to the superficial palmar branch of the radial artery. The flap was sensated by the palmar branch of the superficial radial nerve. The size of the flap averaged 15 x 5 cm and the innervated region of the thenar eminence was an area approximately 5 x 3 cm located over the proximal parts of the abductor pollicis brevis and opponens pollicis muscles. The flap was transferred as a free flap in three patients and as an advancement flap in one patient. The flaps survived completely without complications. Satisfactory restoration of sensation was achieved in the flap area, as shown by 6 mm of average moving two-point discrimination. This combined flap may be a feasible reconstructive option for large palmar defects of the fingers such as degloving injuries.