15Application of Flaps for Coverage of Foot Woundswith Tendon and Bone Exposure Based on aSubunit PrincipleZun-Li Shen, Wan-Xing Jia, Ming-Zhong Hou, Xie-Qing Huang, Yan-Xian Cai, Lan Wang,Yi-Xiong Huang

15.1 Introduction 119

15.2 Patients and Methods 11915.2.1 Patients 11915.2.2 The Subunits of a Foot and the Application of

Flaps 11915.2.3 Reconstructive Options for Different Subunits

of the Foot 11915.2.3.1 General Repair Principle 11915.2.4 Reconstruction of the Plantar Forefoot Region 12015.2.5 Reconstruction of the Dorsal Forefoot Region 12015.2.6 Reconstruction of the Plantar Hindfoot Region 12115.2.7 Reconstruction of the Dorsal Hindfoot Region 12315.2.8 Reconstruction of the Ankle Region 123

15.3 Results 124

15.4 Discussion 124

References 125

15.1Introduction

Foot wounds with exposure of tendon or bone are usu-ally a result of trauma, resection of malignant skin tu-mors, burn injury, or neurotrophic ulceration. Recon-struction of this particular region presents a great chal-lenge due to the limited local soft tissue availability andweight-bearing requirement. Until now, a great num-ber of reconstructive alternatives have been describedin the literature, including cross-leg flaps, local fascio-cutaneous flap or free flaps [1]. However, it is not clearhow to choose the appropriate flaps for the differentparts of the foot [2, 3]. Based on location and extensionof the soft tissue defects, we used 11 local fasciocutane-ous or free flaps for reconstruction, and a subunit re-pair principle was then established.

15.2Patients and Methods15.2.1Patients

Between August 1999 and December 2005, 25 patientswere treated in our department. There were 20 malesand 5 females, ranging in age from 6 to 83 years, with a

mean age of 56 years. The preexisting conditions neces-sitating subsequent reconstruction were resection ofmalignant melanoma or malignant junctional nevus in11 patients, post-traumatic soft tissue defects in 10 pa-tients, burn injury in 2 patients, and neurotrophic ul-ceration in 2 patients. The size of soft tissue defects var-ied from 2×2 cm to 9×8.5 cm.

15.2.2The Subunits of a Foot and the Application of Flaps

According to function, anatomic structure and recon-struction requirements, the foot can be divided intofive subunits: plantar forefoot and dorsal forefoot re-gion, plantar hindfoot and dorsal hindfoot region aswell as ankle region. If the midfoot region is involved, apredominant defect region is defined as one of the fiveabove-mentioned subunits. A complete degloving ofplantar or dorsal foot soft tissue was not seen. The softtissue defects presented in different subunits and thesubsequent flap applications are summarized in Ta-ble 15.1.

15.2.3Reconstructive Options for Different Subunits of the Foot15.2.3.1General Repair Principle

In the case of a malignant skin carcinoma in the foot re-gion, a wide local excision was performed and the intra-operative biopsy showed the clear margin of the wound.Then the wounds were covered primarily by a flap.

If soft tissue defects in the foot were caused by trau-ma, burn or neurotrophic denervation, a complete de-bridement was first performed, including removal ofthe necrosis tissue and granulation tissues as well as theunstable scar around the wounds, then an antibiotictherapy ensued. After the local wound bacterial cultureconfirmed that there was no bacterial contamination, asecondary flap transfer was performed for the woundcoverage.

When transposing a flap as a reverse-flow flap, ateardrop skin paddle was usually designed over the flappedicle. After flap elevation, an incision was made be-

Chapter 15

Table 15.1. The subunits and flap coverage

Subunits Cases Flaps (number)

Plantar forefoot 2 Partial toe flap (1), fillet-ed toe flap (1)

Dorsal forefoot 3 Local DPF (2), free LLLF(1)

Plantar hindfoot (weight-bearing region)

8 MPF (4), MRF+LCF (1)

Plantar hindfoot (non-weightbearing)

3 SNCF (3)

Dorsal hindfoot 2 SNCF (1), PTAF (1)

Ankle (medial malleolus) 3 MSMF (2), LSMF (1)

Ankle (lateral malleolus) 1 Free ALTF (1)

Ankle (Achilles tendon) 3 Local RT (2), SNCF (1)

DPF dorsalis pedis flap, LLLF lateral lower leg flap, MPF medialplantar flap, LCF lateral calcaneal flap, SNFF sural neurocuta-neous flap, PTAF posterior tibial artery flap, MSMF medial su-pramalleolar flap, LSMF lateral supramalleolus flap, ALTF an-terolateral thigh flap, RT rotational flap

tween the flap donor site and the defect site. An opentunnel was then prepared and the teardrop skin paddleleft on the pedicle was used to cover the tunnel.

a b

c d

Fig. 15.1. a View of a defect in the dorsal forefoot. b A free lateral lower leg flap was designed. c The flap was elevated and the pedi-cle based on peroneal vessels was exposed. d Postoperative view of the flap and donor site

15.2.4Reconstruction of the Plantar Forefoot Region

When the wound was located in the plantar forefoot re-gion, a digital pulp flap in reverse fashion or a filleteddigital flap was used.

15.2.5Reconstruction of the Dorsal Forefoot Region

For the dorsal forefoot wound, a local dorsalis pedis ar-tery flap was rotated for the wound coverage. In onecase, there was an extensive soft tissue defect in this re-gion (Fig. 15.1a). The patency of the peroneal artery,posterior tibial artery and anterior tibial artery wasconfirmed prior to the operation. A free ipsilateral lat-eral lower leg flap transplantation, based on the pero-neal vessels, was performed. According to the size ofthe soft tissue defect, the lateral lower leg flap was de-signed in the lateral middle of the lower leg (Fig. 15.1b).The dissection started from the anterior aspect of theflap, and deep in the fascia, then a main cutaneous per-forator could be recognized in the middle of the leg,which usually came from the septum and arose from

120 15 Application of Flaps for Coverage of Foot Wounds with Tendon and Bone Exposure Based on a Subunit Principle

a b

c

Fig. 15.2. a A soft tissue defect resulted from neurotrophic ul-ceration in the plantar weightbearing hindfoot. A medial plan-tar flap was designed. b The medial plantar flap was elevatedand pedicled on medial plantar vessels. c View of the plantarreconstruction 3 months postoperatively

the peroneal artery (Fig. 15.1c). The perforate arteryand two concomitant veins were then dissected in con-nection with the proximal peroneal artery and the ac-companying veins. Finally, the flap was elevated, theperoneal vessels were anastomosed to the dorsalis pe-dis vessels and the donor site was repaired with a split-thickness skin graft (Fig. 15.1d).

15.2.6Reconstruction of the Plantar Hindfoot Region

The plantar hindfoot wounds were usually covered by amedial plantar flap. After the confirmation of patencyof the dorsalis pedis and posterior tibial arteries, theflaps were designed in the instep region according tothe size of the defects (Fig. 15.2a). The flaps were dis-sected in the direction from the medial to lateral side,and the posterior tibial artery was first recognizedproximal to the flap. The abductor hallucis muscle wasdivided and the medial plantar vessels were exposed.The medial plantar vessels should be incorporatedwithin the flap during a meticulous dissection(Fig. 15.2b). Using an interfascicular dissection tech-nique, the cutaneous nerve fascicles originating fromthe medial plantar nerve were retained within the flap.

An incision was made between the flap donor site andthe defect. Finally, a proper tunnel was prepared for thepedicle inset and the flap was transferred to cover thedefect (Fig. 15.2c).

In the lateral heel region, a calcaneal flap was ap-plied (Fig. 15.3a). The flap was dissected from distal toproximal in a supraperiosteal plane. The lateral calca-neal artery and the lesser saphenous vein as well as thesural nerve should be incorporated within the flap(Fig. 15.3b). After flap elevation, the flap was trans-ferred to the recipient area with a skin paddle over thepedicle and the donor site was covered with a split-thickness skin graft (Fig. 15.3c).

Sural neurocutaneous flaps were also used in thecoverage of this region (Fig. 15.4a). A line was markedfrom a point halfway between the Achilles tendon andthe lateral malleolus at the ankle extending to the mid-line between the two heads of the gastrocnemius mus-cle. Usually, we designed a teardrop skin paddle overthe pedicle (Fig. 15.4b). After the proximal sural nerveand the lesser saphenous vein were ligated and divided,the flap was raised under the deep fascia with a pedicleas wide as 3 cm and to include the sural nerve and thelesser saphenous vein. About 5 cm above the tip of thelateral malleolus, a main perforator arising from the

15.2 Patients and Methods 121

a b

c

Fig. 15.3. a The lateral heel defect after a wide resection of a re-current malignant melanoma and a lateral calcaneal flap wasdesigned. b The lateral calcaneal flap was elevated. c Sixmonths after reconstruction

a b

c

Fig. 15.4. a A soft tissue defect left by an extensive resection ofa malignant melanoma in the plantar hindfoot. b A distallybased sural neurocutaneous flap was designed with a teardropskin paddle over the pedicle. c Postoperative view of the flapinset

122 15 Application of Flaps for Coverage of Foot Wounds with Tendon and Bone Exposure Based on a Subunit Principle

a

b

c

Fig. 15.5. a A defect in the medial malleolus region after a wideresection of a malignant junctional nevus. A medial supramal-leolar flap was designed. b The supramalleolar flap based onthe perforators of the posterior tibial artery was elevated. c Oneyear after the wound coverage by the flap

peroneal artery could be recognized. The flap was ro-tated based on the pivotal point to cover the hindfootregion (Fig. 15.4c). The donor site could be closed di-rectly when the width of the flap was less than 4 cm. Thepedicle region could be closed primarily by suture ofthe skin paddle to the tunnel skin.

15.2.7Reconstruction of Dorsal Hindfoot Region

The posterior dorsum wounds were covered by a suralneurofasciocutaneous flap, as described above. A re-versed posterior tibial artery flap was used in our earlycase. The flap was designed along the medial edge ofthe tibia and the pivotal point was above the tip of themedial malleolus. The posterior tibial artery and twoconcomitant veins were first exposed in the proximityof the flap. The flap was then dissected under the deepfascia; the posterior tibial vessels and their perforatorswere included. The flap was finally rotated to cover thedefects in the foot.

15.2.8Reconstruction of Ankle Region

This region can be subdivided into three regions: thelateral malleolus region, the medial malleolus regionand the Achilles tendon region.

In the lateral malleolus region, the soft tissue defectswere reconstructed using a free anterolateral thigh flap.

The flap was based on the descending branch of the lat-eral circumflex femoral artery. A line was drawn be-tween the anterosuperior iliac spine and the lateral bor-der of the patella. Centered in the midpoint of the line,the flap was then outlined and a dissection started inthe direction from lateral to medial under the deep fas-cia. A large fasciocutaneous perforator was usuallyseen arising from the lateral circumflex femoral artery.Then, the pedicle was dissected leaving several strips ofthe vastus lateralis muscle fiber attaching to the pedi-cle, which prevents any damage or kinking of the pedi-cle. Finally, the flap was elevated and the lateral circum-flex femoral vessels were anastomosed to the dorsalispedis vessels. The donor site could be primarily closedwhen the flap width was less than 6 cm. Otherwise, skingrafting was necessary.

When the defect was located around the medial mal-leolus (Fig. 15.5a), a medial supramalleolar flap wasused. The flap was supplied by posterior tibial arteryperforators. Flap dissection was performed betweenthe medial edge of the tibia and middle part of the gas-trocnemius muscle under the deep fascia (Fig. 15.5b).The pivotal point of the flap was about 6 cm above thetip of the medial malleolus, where a main perforatorarising from the posterior tibial artery could be found.The flap was elevated with a pedicle width of 3 cm androtated to the recipient site through a widely under-mined tunnel (Fig. 15.5c).

When the soft tissue defect was located in the proxi-mal part of the medial malleolus region, a lateral supra-

15.2 Patients and Methods 123

Fig. 15.6. Six months after a free anterolateral thigh flap trans-plantation to reconstruct the lateral malleolus region. The flapwas too bulky and secondary debulking was necessary

malleolar flap, which was based on perforators fromthe peroneal artery, was used for the coverage. The axisof the flap was the midline drawn from the anterior tib-ial crest to the posterior margin of the fibula. The pivot-al point was about 5 cm above the tip of the lateral mal-leolus. The flap was dissected under the deep fascialeaving a subcutaneous pedicle 3 cm wide to improvethe venous return. To avoid compression, a wide tunnelwas made between the pivotal point and the recipientsite. Finally, the donor site was closed by a split-thick-ness skin graft.

The soft tissue defects located in the ankle Achillestendon region were covered by a sural fasciocutaneousflap or regional rotation flaps.

15.3Results

All cases were followed up from 3 months to 67 months,with an average of 30 months. Two cases with regionalrotation flaps for the Achilles tendon’s coverage under-went marginal flap necrosis and healed by local woundcare. One patient ambulated 2 weeks after the suralneurofasciocutaneous flap transfer was used to coverthe heel region; the wound dehiscence and partial su-perficial skin necrosis occurred between the flap anddonor site. It was healed by wound dressing changes.All the other flaps survived uneventfully. However, thefree anterolateral thigh flap was bulky in the lateralmalleolus region (Fig. 15.6). It had to be debulked halfa year after the first operation. It was demonstrated thatall flaps had normal or protective sensitivity withoutany skin breakdown (Fig. 15.7). All patients ambulatedwell and could wear normal shoes.

Fig. 15.7. Two years after reconstruction of the plantar hindfootwith a distally based sural neurocutaneous flap. No recurrentulceration or skin breakdown was observed

15.4Discussion

It is vital for a foot to support standing and walking.Any soft tissue defects in the foot will impede the nor-mal activities of patients. The skin and soft tissue un-derneath are different in various parts of a foot. Theplantar skin is glabrous and thick with solid anchorageto the deep structure. Therefore, the reconstructionaim is to restore the stability of the foot skin to adapt tothe weight-bearing and to resist shearing force. In addi-tion, a good sensibility should be taken into account forthe reconstruction. The skin in the foot dorsum is thinand pliable, while the ankle region has great tensionduring movement, and a good stability is required forshoe-wearing. Considering these structural differ-ences, we thought that the subunit repair principlecould assist us in choosing proper flaps in the recon-struction of the foot.

In the case of small soft tissue defects in the forefoot,partial toe fillet flaps or webspace flaps based on theplantar circulation could be used without toe amputa-tion. Sometimes, these defects were associated with di-abetes mellitus or peripheral vascular disease. Thus,the toe fillet flap was often the primary reconstructivechoice [4]. Recently, it was reported that the medialplantar flap could be transferred as a distally basedpedicled island flap. The small to moderate size woundlocated in the plantar forefoot could be repaired withthis glabrous skin flap [5, 6]. The precondition of thisprocedure was that the dorsalis pedis artery and theposterior tibial artery should be patent. In the lateral or

124 15 Application of Flaps for Coverage of Foot Wounds with Tendon and Bone Exposure Based on a Subunit Principle

medial site of the forefoot, a local dorsal pedis flapcould be rotated to cover small or moderate-sizedwounds satisfactorily.

According to our own experience, a distally basedfasciocutaneous flap could not cover the forefoot reli-ably. A free flap had to be used to repair this regionwhen there was an extensive soft tissue defect. In ourseries, a free ipsilateral lower leg flap based on the pero-neal vessels was applied. This flap was thin with a con-stant vascular anatomy. The procedure could be per-formed by one microsurgical team using one tourni-quet. However, the main disadvantage was having tosacrifice the peroneal artery and the dorsalis pedis ar-tery, and the fact that the perfusion of the foot may becompromised. The confirmation of the patency of theposterior tibial artery was necessary prior to the opera-tion. Alternatively, the contralateral lateral lower legflaps or forearm flaps as well as the medial sural arteryflap [7] can be selected as free flaps for the coverage ofthe forefoot.

The plantar hindfoot, especially the weightbearingregion, requires thick, sensorial, durable and glabrousskin. The medial plantar artery flap raised from thenonweightbearing instep of the plantar foot is a sensateflap. The skin texture is similar to that of the weight-bearing region. Therefore, it is an ideal approach to re-surfacing the plantar hindfoot region [8]. However, theflap offers limited soft tissue for coverage of an exten-sive soft tissue defects in the lateral heel. The lateral cal-caneal artery flap has provided a good alternative tothis defect [9]. We used the medial plantar flap com-bined with a lateral calcaneal artery flap in this situa-tion. Both flaps had good sensibility and provided du-rable skin and soft tissue; no recurrent ulceration wasobserved postoperatively. When the soft tissue cover-age was located in the instep region, a distally based su-ral neurocutaneous flap was transferred and fit this re-gion well.

For the soft tissue defect located in the dorsal hind-foot, the distally based sural neurocutaneous flap was agood reconstructive option [10, 11]. In our previous se-ries, we used a distally based posterior tibial artery flap.The flap was very reliable and provided enough soft tis-sues for wound coverage. However, the sacrifice of amain artery of the foot may worsen the injured foot.Thus, the flap should not be the first choice for recon-struction.

In the ankle region, local rotational flaps were at-tempted for the wound coverage in two cases. The par-tial flap loss resulted in delayed wound healing due tothe tight tension of the local tissue. So, it seemed that alocal rotation flap was not appropriate for reconstruc-tion of this region. The lateral calcaneal flap and medialor lateral supramalleolar flap were good alternativesfor wond coverage in the lateral or medial malleolus re-gion [12–14]. They had the common advantage of not

sacrificing the main blood vessels of the foot. However,they were only suitable for coverage of small to moder-ate-size wounds as they do not provide sufficient skinand soft tissue. For the coverage of extensive soft tissuedefects, we used a free anterolateral thigh flap. The dis-advantage was that the flap was very bulky and madeshoe-wearing difficult. Recently, a thinned anterolate-ral thigh flap was described and may be used instead ofthe traditional anterolateral thigh flap [15]. Alterna-tively, when the main perforator is not jeopardized bythe trauma, the distally based sural neurocutaneousflap is suitable for reconstruction of extensive soft tis-sue defects in this region [16].

The main complication of reverse flow flaps was ve-nous congestion. In our series, we did not see this com-plication. We thought the following points might play avital role in the raising of a reverse flow flap for recon-struction of foot soft tissue defects. Firstly, the pivotalpoint of the flap should be detected before the opera-tion using Doppler ultrasound or angiography. Thedistance from the pivotal point to the closest edge of theskin defect was measured. A 1- to 2-cm length shouldbe added to the pedicle length for the rotation of thepedicle. The design of flaps was 1 cm larger than theoriginal size of the defects to facilitate the final closureof the wounds. Secondarily, the flaps were elevated un-der the deep fascia plane and superficially in the sub-dermal plane to protect the pedicle. The subcutaneouspedicle should be as wide as 3 cm to improve the ve-nous return. Finally, a wide tunnel was made betweenthe pivotal point and the recipient site. A teardrop skinpaddle was left over the pedicle to facilitate the closureof the tunnel. Drainage was necessary to prevent thepostoperative hematoma under the flaps. All thesemeasures contributed to a wound closure without ten-sion and allowed good perfusion of flaps. However, thereverse flow flaps were primarily non-sensory flapsand could not resist the shearing force during standingand walking in an early postoperative period. Other-wise, a persistent ulceration likely occurred at the junc-tion between the flap and the local skin. Therefore, itwas suggested that patients wear protective shoes andavoid weight-bearing prior to normal ambulation.

References

1. Heitmann C, Levin LS (2003) The orthoplastic approach formanagement of the severely traumatized foot and ankle. JTrauma 54:379–390

2. Baumeister S, Germann G (2001) Soft tissue coverage of theextremely traumatized foot and ankle. Foot Ankle Clin6:867–903

3. Levin LS (2006) Foot and ankle soft-tissue deficiencies: whoneeds a flap? Am J Orthop 35:11–19

4. Kuntscher MV, Erdmann D, Homann HH et al (2001) Theconcept of fillet flaps: classification, indications, and analy-sis of their clinical value. Plast Reconstr Surg 108:885–896

References 125

5. Butler CE, Chevray P (2002) Retrograde-flow medial plan-tar island flap reconstruction of distal forefoot, toe, andwebspace defects. Ann Plast Surg 49:196–201

6. Acikel C, Celikoz B, Yuksel F et al (2003) Various applica-tion of the medial plantar flap to cover the defects of theplantar foot, posterior heel, and ankle. Ann Plast Surg50:498–503

7. Chen SL, Chuang CJ, Chou TD et al (2005) Free medial su-ral artery perforator flap for ankle and foot. Ann Plast Surg54:39–43

8. Benito-Ruiz J, Yoon T, Guisantes-Pintos E et al (2004) Re-construction of soft-tissue defects of the heel with localfasciocutaneous flaps. Ann Plast Surg 52:380–384

9. Demirseren ME, Gokrem S, Can Z (2004) Reappraisal of is-land modification of lateral calcaneal artery skin flap. PlastReconstr Surg 113:1167–1174

10. Hollier L, Sharma S, Babigumira E et al (2002) Versatilityof the sural fasciocutaneous flap in the coverage of lowerextremity wounds. Plast Reconstr Surg 110:1673–1679

11. Chang SM, Zhang F, Yu GR et al (2004) Modified distally

based peroneal artery perforator flap for reconstruction offoot and ankle. Microsurgery 24:430–436

12. Touam C, Rostoucher P, Bhatia A et al (2001) Comparativestudy of two series of distally based fasciocutaneous flapsfor coverage of the lower one fourth of the leg, the ankle,and the foot. Plast Reconstr Surg 107:383–392

13. Voche P, Merle M, Stussi JD (2005) The lateral supramalle-olar flap-experience with 41 flaps. Ann Plast Surg 54:49–54

14. Ozdemir R, Kocer U, Sahin B et al (2006) Examination ofthe skin perforators of the posterior tibial artery on the legand the ankle region and their clinical use. Plast ReconstrSurg 117:1619–1630

15. Yang WG, Chiang YC, Wei FC et al (2006) Thin anterolate-ral thigh perforator flap using a modified perforator mi-crodissection technique and it clinical application for footresurfacing. Plast Reconstr Surg 117:1004–1008

16. Chen SL, Chen TM, Chou TD et al (2002) The distallybased lesser saphenous venofasciocutaneous flap for ankleand heel reconstruction. Plast Reconstr Surg 110:1664–1672

126 15 Application of Flaps for Coverage of Foot Wounds with Tendon and Bone Exposure Based on a Subunit Principle