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A reverse flow cross finger pedicle skin flap from hemidorsum of finger
Journal of Plastic, Reconstructive & Aesthetic Surgery (2010) 63, 686e692
A reverse flow cross finger pedicle skin flap from hemidorsum of finger Satyanarayan Mishra*, S. Manisundaram Department of Plastic Surgery, Rajah Muthiah Medical College, Annamalai University, Annamalainagar, Tamilnadu 608002, India Received 4 March 2007; accepted 30 January 2009
KEYWORDS Skin transplantation; Hand; Hand injuries; Finger injuries
Summary A reverse-flow cross-finger pedicle skin flap raised from the hemidorsum has been used, which is a modification of the distally based dorsal cross-finger flap. The flap is raised from the hemidorsum at a plane above the paratenon, the distal-most location of the base being at the level of the distal interphalangeal joint. Thirty-two flaps were used from as many fingers of as many patients. Of these, 31 (97%) flaps survived fully; there was stiffness of finger in one (3%) patient and the two-point discrimination was 4e8 mm (n Z 14). Follow-up period was 2 months to 3 years, the median being 1 year and 3 months. The advantages of this flap are that there is less disruption of veins and less visible disfigurement of the dorsum of the finger when compared to other pedicled cross-finger skin flaps. The disadvantage of this flap is its restricted width. It is recommended as the cross-finger pedicle skin flap of choice when the defect is not wide. ª 2009 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.
A finger defect with bone, tendon or joint exposure needs covering by a flap. When a flap from the same finger is either not possible or not acceptable, a cross-finger flap may become necessary, the common type being a crossfinger pedicle skin flap. Laterally based cross-finger flaps,1,2 laterally based reverse-dermis cross-finger flap1,2 and distally based dorsal cross-finger pedicle skin flaps2,3 have been described in literature. All these flaps use skin either from near total or from total width of the dorsum, which disrupts most of the dorsal veins and causes easily visible disfigurement of the * Corresponding author. Tel.: þ91 4144 238461. E-mail address: [email protected] (S. Mishra).
dorsum. The transdigital retrograde flap4 raised from the sides of the fingers includes skin from the palmar aspect which causes easily visible disfigurement of the donor area. The present cross-finger flap is an attempt to minimise the venous disruption and the disfigurement of the finger.
Materials and methods Vascular anatomy of the flap The fingers are rich in vascularity provided through two digital arteries to each. Each digital artery gives off four
1748-6815/$ - see front matter ª 2009 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.bjps.2009.01.042
Reverse flow cross finger pedicle skin flap dorsal branches for each phalanx, viz., condylar, metaphyseal, the dorsal skin branch and the transverse palmar arch.5 In addition, the dorsal skin is supplied through two dorsal digital arteries which are the terminal branches of the dorsal metacarpal arteries. Over the dorsum of the distal phalanx there are three transverse dorsal arches, viz., proximal matrix, middle matrix and distal matrix arch (Figure 1). Existence of a dorsal arterial network has also been identified (Figure 2). The dorsal digital artery branches may either join the dorsal digital network or terminate at the level of the proximal third of the proximal phalanx.6 The blood supply to the present flap comes not only from the dorsal skin vessels of the same side but also from the other hemidorsum through the dorsal arterial arcades distal to the base of the flap and through the matrix arches.
Figure 1 Diagram of side view of finger showing the arterial supply of the dorsum. DA e Digital artery. DDA e Dorsal digital artery. a e Branch to condylar head, b e Metaphyseal branch, c e Dorsal cutaneous branch, d e Transverse Palmar arch, PMA e Proximal matrix arch, MMA e Middle matrix arch, DMA e Distal matrix arch (Redrawn from J. Hand Surgery, 1990; 15A. Strauch B, Mouraw De; Arterial system of the Finger, 148e54, Copyright Elsevier: With permission).
687
Operative technique (Figure 3) Either a finger or an arm tourniquet is used. A digital block is enough for adults. Children need general anaesthesia. The flap is designed on the dorsum of the adjacent finger selecting the hemidorsum which is closer to the defect of the recipient finger. For a central defect of the finger (e.g., an amputation stump), when two competing donor fingers are available, the finger which is functionally less important should be chosen. Extra length of about 25% is planned to prevent tension on the pedicle. The flap is distally based, lying between the mid-lateral line and the midline on the dorsum of the finger (Figure 2). It should be raised from an area covering the hemidorsum of the middle phalanx and distal two-thirds of the proximal phalanx. Including skin from over the distal phalanx should be avoided in order to ensure the protection of the distal dorsal cutaneous branch of the digital artery and the matrix
Figure 2 Diagram of oblique view of finger sharing the dorsal arterial arcades and a flap marked over the middle phalanx (Redrawn from Plast. Reconstr. Surg, 1994; 93. Bene MD, Petrolati M, Raimond P et al; Reverse dorsal digital island flap, 552e7, Copyright Elsevier: with permission).
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S. Mishra, S. Manisundaram
Figure 3 a) Diagram of hand showing amputated tip of index finger and marking flap marked over the middle phalanx. b) The flap is raised and the tie-over dressing applied over the secondary defect. c) Flap is inset to the defect.
arches. Similarly, skin from over the proximal third of the proximal phalanx should not be included because of the possibility of discontinuity of the dorsal arterial network. After incising the skin, subcutaneous tissue and the deep fascia, the flap is raised from the tip towards the base at a level just above the paratenon taking care not to injure it. During the incision on the mid-lateral line, due precaution is taken not to injure the digital neurovascular bundle by keeping the incision bevelled in a dorsal direction. As much as possible the flap should be raised either on the proximal phalanx or on the middle phalanx. An incision across the proximal interphalangeal joint crease should be avoided to prevent a scar contracture, though it is not mandatory. While raising a flap over the proximal phalanx, inclusion of the web margin should be avoided and, instead, the incision should be made 2 mm dorsal to it. A length-to-breadth ratio of up to 2:1 has been used in the present series. The secondary defect is split skin grafted and a thin tie-over dressing is applied, since a thick dressing will restrict the available length of the small flap. The flap is inset to the defect. Both the recipient and the donor fingers are immobilised either with a plaster-of-Paris splint or over a cotton ball on the palm. The flap is divided between 2 and 3 weeks after the operation.
25years. The causes of the defects (Table 1) were crush injuries, electrical burns, release of burn contractures, cracker-burst injuries, human bite and excision of tender scar. In one patient, a digital nerve, without digital vessels, was included in the flap which included 2 mm of the palmar skin.
Results Thirty-one (97%) flaps survived fully (Figures 4e16). There was cuticular necrosis of the tip of one (3%) flap, but the flap survived. There was stiffness of finger in one (3%) patient. None of the patients reported cold intolerance. Two-point discrimination at the tip (n Z 14) was 4e8 mm, the average being 6.5 mm at 1 year follow-up. The donorarea disfigurement was confined to the hemidorsum, but over time the skin graft contracted, making the disfigurement smaller (Figure 7). During follow-up, the patients were shown some photographs of results of the donor area of laterally based cross-finger flaps and all of them felt the appearance of their own finger was better(Figures 8,15). The initial depression in the contour of the donor defect improved over time. But it persisted, though in mild
Patients Thirty-two flaps were used in 32 fingers of 32 patients. Twenty-six (81%) were male and six (19%) were female. Their ages ranged from 1 to 56 years, the median being
Table 1
Causes of finger defects
Causes
NO(%)
Crush Amputation Electrical Burns Release of burn contracture Blast injury Human bite Excision of tender scar Total
20 (62.5) 5 (15.6) 3 (9.3) 2 (6.25) 1 (3.1) 1 (3.1) 32
Figure 4 (Case1) Crush amputation of (R) ring finger (Pre operative view) showing the defect and the flap marked on middle finger.
Reverse flow cross finger pedicle skin flap
Figure 5
689
(Case 1) The flap before division.
form, even during late follow-up (Figure 7). But no patient complained about it. None of the patients reported any sensitivity or difficulty in the skin grafts over contact areas. The follow-up period ranged from 2 months to 3 years, the median being 1 year and 2 months.
Figure 7 (Case 1) Follow up dorsal view showing healed flap with minimally visible donor area.
A homodigital flap for reconstruction of finger defects is normally preferred. At times, due to involvement of the possible donor sites themselves in the process of trauma, it may not be feasible. The reverse digital artery flaps7 can be used on many occasions, but they suffer from the disadvantage of sacrificing a digital artery. A cross-finger flap can be useful for overcoming the above difficulties. The laterally based1,2 and the distally based2,3 crossfinger flaps disrupt the dorsal veins of fingers over almost the whole width. Even though no complication of this effect
has been reported, it contravenes physiology. The present flap spares the dorsal veins from one hemidorsum and hence is less likely to affect the physiology. The distally based dorsal cross-finger flap2,3 is raised with the centre on the midline of the dorsum. It has a limited range for the purpose of covering the adjacent finger because it is wide and its pivot point is located several millimeters away from the midline.. The present flap has a narrower base with the pivot point on the centre of the dorsum of the donor finger and, hence, has a greater range for coverage of the adjacent finger. Moreover, the dorsal skin is somewhat mobile, which allows additional movement of the pivot point, thus increasing the range further. The survival of this flap has not been a problem because of the rich vascular anastomosis on the dorsum. In the present flap, the skin-grafted area over the hemidorsum becomes smaller with the passage of time due to contraction of the skin graft which easily draws in the mobile dorsal skin. But the presence of grafted skin over
Figure 6
Figure 8 function.
Discussion
(Case 1) Follow up palmar view showing healed flap.
(Case1) Follow up view showing full recovery of
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S. Mishra, S. Manisundaram
Figure 11 (Case 2) Follow up view showing the healed flap and minimally visible donor area. Figure 9 (Case 2) Pre operative view of electrical burn e ulcer dorsum of (L) little finger with exposed PIP (Proximal Interphalangeal joint) and the flap marking on the ring finger.
the hemidorsum violates the concept of aesthetic unit, which should, ideally, include the whole width of the dorsum of the finger. In the present series, all the patients were South Asians with dark skin and a tendency for gross hyperpigmentation of the grafted skin. This is probably the reason why they felt that a smaller skin-grafted secondary defect, as in the present flap, was better than a larger area of grafted skin encompassing the whole width of the dorsum of the finger, as in other types of cross-finger flaps. However, the level of satisfaction with the cosmesis of the donor area may not be the same in patients with lighter skin, in whom the colour of the skin graft blends better with the surrounding normal skin. They may prefer a donor area with skin graft over the whole width of the dorsum of the finger to skin graft only over the hemidorsum. In the transdigital distally based flap,4 the authors have used palmar skin in addition to dorsal skin. The hyperpigmented look of the skin graft on the palmar aspect of the
Figure 10
(Case 2) The flap before division.
secondary defect becomes easily visible and, hence, cosmetically less acceptable. The present flap has certain disadvantages. Its width is limited. However, this is sufficient for covering most of the amputation stumps and other finger defects. The depressed contour of the donor defect is a cosmetic disadvantage. However, this can occur in other finger flaps too, when fullthickness tissue is removed from the donor site. Further, the flap is not sensate. To overcome this, if necessary, the dorsal branch of the digital nerve can be included in the flap as in an innervated cross-finger flap for finger tip reconstruction.8 A neurovascular island flap9,10 can easily provide sensation. However, since it sacrifices a digital neurovascular bundle, it may ideally be reserved for covering the defects on the thumb tips only.
Figure 12 (Case 3) Electrical burns dorsum of (R) thumb with exposed interphalangeal joint.
Reverse flow cross finger pedicle skin flap
Figure 13 division.
(Case 3) The flap from middle finger before
691
Figure 15 (Case 3) Follow up view showing minimally visible donor area.
However, the tips regained protective sensation at the end of 1 year (n Z 14) with a two-point discrimination of 4e8 mm (average of 6.5 mm) in the present flap, which is acceptable. It is for this reason that even though a digital nerve was included in one flap with a resultant two-point discrimination of 4 mm, it is considered not to be necessary for the fingers. Cross-finger flaps have the potential to cause stiffness of the fingers. In the present series it happened in only one (3%) case, an elderly patient whose fingers had been immobilised for 3 weeks. The occurrence of stiffness can be reduced by dividing the flaps and mobilising the fingers earlier, and also by avoiding this procedure in elderly patients. The present flap is a modification of the distally based cross-finger flap in the following manner, viz., by restricting the flap to the hemidorsum. It is a reliable flap. It causes less dorsal venous disruption and may be cosmetically more Figure 16
(Case 3) Follow up showing function.
acceptable, especially in coloured people, than other pedicled cross-finger flaps. It is recommended as the cross-finger pedicle skin flap of choice when the defect is not wide.
Acknowledgements We thank the Dean, Faculty of Medicine and the Medical Superintendent, Rajah Muthiah Medical College Hospital, Annamalai University for their kind permission to use the patient records. We also thank Mr. A. Felix, Reader in Statistics, for his guidance and Dr. David C. Arumainayagam, Professor of Medicine, for his help in refining the English of the manuscript.
References Figure 14
(Case 3) Showing the healed flap.
1. Russel RC. Fingertip injuries. In: McCarthy J, editor. Plastic Surgery. 1st ed. Philadelphia: W.B. Saunders; 1990. p. 4477e98.
692 2. Edgerton BW, Beasley RW. Dorsal cross finger flaps. In: Strauch B, Vasconez LO, Hall Findlay EJ, editors. Grabb’s Encylopedia of Flaps. 1st ed. Boston: Little Brown & Co.; 1990. p. 905e10. 3. Curtis RM. Cross finger pedicle flap in hand surgery. Ann surgery 1957;145:650e5. 4. Gurdin M, Pangman J. The repair of surface defects of fingers by transdigital flaps. Plast Reconstr Surg 1950;5: 368e71. 5. Strauch B, Mouraw De. Arterial system of the finger. J Hand Surg 1990;15A:148e54. 6. Bene MD, Petrolati M, Raimond P, et al. Reverse dorsal digital island flap. Plast Reconstr Surg 1994;93:552e7.
S. Mishra, S. Manisundaram 7. Niranjan NS, Armstrong JR. A homodigital reverse pedicle island flap in soft tissue reconstruction of the finger and the thumb. J Hand Surg (British & European) 1994;19B:135e41. 8. Cohen BE, Cronin ED. An innervated cross finger flap for fingertip reconstruction. Plast Reconstr Surg 1983;72: 688e97. 9. Markley JM, Littler JW. Digital neurovascular island skin flap. In: Strauch B, Vasconez LO, Hall-Findlay EJ, editors. Grabb’s Encyclopedia of Flaps. 1st ed. Boston: Little Brown & Co; 1990. p. 887e91. 10. Venkataswami R. Staged neurovascular island skin flap from the middle finger to the thumb tip. In: Strauch B, Vasconez LO, Hall-Findlay EJ, editors. Grabb’s Encyclopedia of Flaps. 1st ed. Boston: Little Brown & Co; 1990. p. 892e4.
A reverse flow cross finger pedicle skin flap from hemidorsum of finger Satyanarayan Mishra*, S. Manisundaram Department of Plastic Surgery, Rajah Muthiah Medical College, Annamalai University, Annamalainagar, Tamilnadu 608002, India Received 4 March 2007; accepted 30 January 2009
KEYWORDS Skin transplantation; Hand; Hand injuries; Finger injuries
Summary A reverse-flow cross-finger pedicle skin flap raised from the hemidorsum has been used, which is a modification of the distally based dorsal cross-finger flap. The flap is raised from the hemidorsum at a plane above the paratenon, the distal-most location of the base being at the level of the distal interphalangeal joint. Thirty-two flaps were used from as many fingers of as many patients. Of these, 31 (97%) flaps survived fully; there was stiffness of finger in one (3%) patient and the two-point discrimination was 4e8 mm (n Z 14). Follow-up period was 2 months to 3 years, the median being 1 year and 3 months. The advantages of this flap are that there is less disruption of veins and less visible disfigurement of the dorsum of the finger when compared to other pedicled cross-finger skin flaps. The disadvantage of this flap is its restricted width. It is recommended as the cross-finger pedicle skin flap of choice when the defect is not wide. ª 2009 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.
A finger defect with bone, tendon or joint exposure needs covering by a flap. When a flap from the same finger is either not possible or not acceptable, a cross-finger flap may become necessary, the common type being a crossfinger pedicle skin flap. Laterally based cross-finger flaps,1,2 laterally based reverse-dermis cross-finger flap1,2 and distally based dorsal cross-finger pedicle skin flaps2,3 have been described in literature. All these flaps use skin either from near total or from total width of the dorsum, which disrupts most of the dorsal veins and causes easily visible disfigurement of the * Corresponding author. Tel.: þ91 4144 238461. E-mail address: [email protected] (S. Mishra).
dorsum. The transdigital retrograde flap4 raised from the sides of the fingers includes skin from the palmar aspect which causes easily visible disfigurement of the donor area. The present cross-finger flap is an attempt to minimise the venous disruption and the disfigurement of the finger.
Materials and methods Vascular anatomy of the flap The fingers are rich in vascularity provided through two digital arteries to each. Each digital artery gives off four
1748-6815/$ - see front matter ª 2009 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.bjps.2009.01.042
Reverse flow cross finger pedicle skin flap dorsal branches for each phalanx, viz., condylar, metaphyseal, the dorsal skin branch and the transverse palmar arch.5 In addition, the dorsal skin is supplied through two dorsal digital arteries which are the terminal branches of the dorsal metacarpal arteries. Over the dorsum of the distal phalanx there are three transverse dorsal arches, viz., proximal matrix, middle matrix and distal matrix arch (Figure 1). Existence of a dorsal arterial network has also been identified (Figure 2). The dorsal digital artery branches may either join the dorsal digital network or terminate at the level of the proximal third of the proximal phalanx.6 The blood supply to the present flap comes not only from the dorsal skin vessels of the same side but also from the other hemidorsum through the dorsal arterial arcades distal to the base of the flap and through the matrix arches.
Figure 1 Diagram of side view of finger showing the arterial supply of the dorsum. DA e Digital artery. DDA e Dorsal digital artery. a e Branch to condylar head, b e Metaphyseal branch, c e Dorsal cutaneous branch, d e Transverse Palmar arch, PMA e Proximal matrix arch, MMA e Middle matrix arch, DMA e Distal matrix arch (Redrawn from J. Hand Surgery, 1990; 15A. Strauch B, Mouraw De; Arterial system of the Finger, 148e54, Copyright Elsevier: With permission).
687
Operative technique (Figure 3) Either a finger or an arm tourniquet is used. A digital block is enough for adults. Children need general anaesthesia. The flap is designed on the dorsum of the adjacent finger selecting the hemidorsum which is closer to the defect of the recipient finger. For a central defect of the finger (e.g., an amputation stump), when two competing donor fingers are available, the finger which is functionally less important should be chosen. Extra length of about 25% is planned to prevent tension on the pedicle. The flap is distally based, lying between the mid-lateral line and the midline on the dorsum of the finger (Figure 2). It should be raised from an area covering the hemidorsum of the middle phalanx and distal two-thirds of the proximal phalanx. Including skin from over the distal phalanx should be avoided in order to ensure the protection of the distal dorsal cutaneous branch of the digital artery and the matrix
Figure 2 Diagram of oblique view of finger sharing the dorsal arterial arcades and a flap marked over the middle phalanx (Redrawn from Plast. Reconstr. Surg, 1994; 93. Bene MD, Petrolati M, Raimond P et al; Reverse dorsal digital island flap, 552e7, Copyright Elsevier: with permission).
688
S. Mishra, S. Manisundaram
Figure 3 a) Diagram of hand showing amputated tip of index finger and marking flap marked over the middle phalanx. b) The flap is raised and the tie-over dressing applied over the secondary defect. c) Flap is inset to the defect.
arches. Similarly, skin from over the proximal third of the proximal phalanx should not be included because of the possibility of discontinuity of the dorsal arterial network. After incising the skin, subcutaneous tissue and the deep fascia, the flap is raised from the tip towards the base at a level just above the paratenon taking care not to injure it. During the incision on the mid-lateral line, due precaution is taken not to injure the digital neurovascular bundle by keeping the incision bevelled in a dorsal direction. As much as possible the flap should be raised either on the proximal phalanx or on the middle phalanx. An incision across the proximal interphalangeal joint crease should be avoided to prevent a scar contracture, though it is not mandatory. While raising a flap over the proximal phalanx, inclusion of the web margin should be avoided and, instead, the incision should be made 2 mm dorsal to it. A length-to-breadth ratio of up to 2:1 has been used in the present series. The secondary defect is split skin grafted and a thin tie-over dressing is applied, since a thick dressing will restrict the available length of the small flap. The flap is inset to the defect. Both the recipient and the donor fingers are immobilised either with a plaster-of-Paris splint or over a cotton ball on the palm. The flap is divided between 2 and 3 weeks after the operation.
25years. The causes of the defects (Table 1) were crush injuries, electrical burns, release of burn contractures, cracker-burst injuries, human bite and excision of tender scar. In one patient, a digital nerve, without digital vessels, was included in the flap which included 2 mm of the palmar skin.
Results Thirty-one (97%) flaps survived fully (Figures 4e16). There was cuticular necrosis of the tip of one (3%) flap, but the flap survived. There was stiffness of finger in one (3%) patient. None of the patients reported cold intolerance. Two-point discrimination at the tip (n Z 14) was 4e8 mm, the average being 6.5 mm at 1 year follow-up. The donorarea disfigurement was confined to the hemidorsum, but over time the skin graft contracted, making the disfigurement smaller (Figure 7). During follow-up, the patients were shown some photographs of results of the donor area of laterally based cross-finger flaps and all of them felt the appearance of their own finger was better(Figures 8,15). The initial depression in the contour of the donor defect improved over time. But it persisted, though in mild
Patients Thirty-two flaps were used in 32 fingers of 32 patients. Twenty-six (81%) were male and six (19%) were female. Their ages ranged from 1 to 56 years, the median being
Table 1
Causes of finger defects
Causes
NO(%)
Crush Amputation Electrical Burns Release of burn contracture Blast injury Human bite Excision of tender scar Total
20 (62.5) 5 (15.6) 3 (9.3) 2 (6.25) 1 (3.1) 1 (3.1) 32
Figure 4 (Case1) Crush amputation of (R) ring finger (Pre operative view) showing the defect and the flap marked on middle finger.
Reverse flow cross finger pedicle skin flap
Figure 5
689
(Case 1) The flap before division.
form, even during late follow-up (Figure 7). But no patient complained about it. None of the patients reported any sensitivity or difficulty in the skin grafts over contact areas. The follow-up period ranged from 2 months to 3 years, the median being 1 year and 2 months.
Figure 7 (Case 1) Follow up dorsal view showing healed flap with minimally visible donor area.
A homodigital flap for reconstruction of finger defects is normally preferred. At times, due to involvement of the possible donor sites themselves in the process of trauma, it may not be feasible. The reverse digital artery flaps7 can be used on many occasions, but they suffer from the disadvantage of sacrificing a digital artery. A cross-finger flap can be useful for overcoming the above difficulties. The laterally based1,2 and the distally based2,3 crossfinger flaps disrupt the dorsal veins of fingers over almost the whole width. Even though no complication of this effect
has been reported, it contravenes physiology. The present flap spares the dorsal veins from one hemidorsum and hence is less likely to affect the physiology. The distally based dorsal cross-finger flap2,3 is raised with the centre on the midline of the dorsum. It has a limited range for the purpose of covering the adjacent finger because it is wide and its pivot point is located several millimeters away from the midline.. The present flap has a narrower base with the pivot point on the centre of the dorsum of the donor finger and, hence, has a greater range for coverage of the adjacent finger. Moreover, the dorsal skin is somewhat mobile, which allows additional movement of the pivot point, thus increasing the range further. The survival of this flap has not been a problem because of the rich vascular anastomosis on the dorsum. In the present flap, the skin-grafted area over the hemidorsum becomes smaller with the passage of time due to contraction of the skin graft which easily draws in the mobile dorsal skin. But the presence of grafted skin over
Figure 6
Figure 8 function.
Discussion
(Case 1) Follow up palmar view showing healed flap.
(Case1) Follow up view showing full recovery of
690
S. Mishra, S. Manisundaram
Figure 11 (Case 2) Follow up view showing the healed flap and minimally visible donor area. Figure 9 (Case 2) Pre operative view of electrical burn e ulcer dorsum of (L) little finger with exposed PIP (Proximal Interphalangeal joint) and the flap marking on the ring finger.
the hemidorsum violates the concept of aesthetic unit, which should, ideally, include the whole width of the dorsum of the finger. In the present series, all the patients were South Asians with dark skin and a tendency for gross hyperpigmentation of the grafted skin. This is probably the reason why they felt that a smaller skin-grafted secondary defect, as in the present flap, was better than a larger area of grafted skin encompassing the whole width of the dorsum of the finger, as in other types of cross-finger flaps. However, the level of satisfaction with the cosmesis of the donor area may not be the same in patients with lighter skin, in whom the colour of the skin graft blends better with the surrounding normal skin. They may prefer a donor area with skin graft over the whole width of the dorsum of the finger to skin graft only over the hemidorsum. In the transdigital distally based flap,4 the authors have used palmar skin in addition to dorsal skin. The hyperpigmented look of the skin graft on the palmar aspect of the
Figure 10
(Case 2) The flap before division.
secondary defect becomes easily visible and, hence, cosmetically less acceptable. The present flap has certain disadvantages. Its width is limited. However, this is sufficient for covering most of the amputation stumps and other finger defects. The depressed contour of the donor defect is a cosmetic disadvantage. However, this can occur in other finger flaps too, when fullthickness tissue is removed from the donor site. Further, the flap is not sensate. To overcome this, if necessary, the dorsal branch of the digital nerve can be included in the flap as in an innervated cross-finger flap for finger tip reconstruction.8 A neurovascular island flap9,10 can easily provide sensation. However, since it sacrifices a digital neurovascular bundle, it may ideally be reserved for covering the defects on the thumb tips only.
Figure 12 (Case 3) Electrical burns dorsum of (R) thumb with exposed interphalangeal joint.
Reverse flow cross finger pedicle skin flap
Figure 13 division.
(Case 3) The flap from middle finger before
691
Figure 15 (Case 3) Follow up view showing minimally visible donor area.
However, the tips regained protective sensation at the end of 1 year (n Z 14) with a two-point discrimination of 4e8 mm (average of 6.5 mm) in the present flap, which is acceptable. It is for this reason that even though a digital nerve was included in one flap with a resultant two-point discrimination of 4 mm, it is considered not to be necessary for the fingers. Cross-finger flaps have the potential to cause stiffness of the fingers. In the present series it happened in only one (3%) case, an elderly patient whose fingers had been immobilised for 3 weeks. The occurrence of stiffness can be reduced by dividing the flaps and mobilising the fingers earlier, and also by avoiding this procedure in elderly patients. The present flap is a modification of the distally based cross-finger flap in the following manner, viz., by restricting the flap to the hemidorsum. It is a reliable flap. It causes less dorsal venous disruption and may be cosmetically more Figure 16
(Case 3) Follow up showing function.
acceptable, especially in coloured people, than other pedicled cross-finger flaps. It is recommended as the cross-finger pedicle skin flap of choice when the defect is not wide.
Acknowledgements We thank the Dean, Faculty of Medicine and the Medical Superintendent, Rajah Muthiah Medical College Hospital, Annamalai University for their kind permission to use the patient records. We also thank Mr. A. Felix, Reader in Statistics, for his guidance and Dr. David C. Arumainayagam, Professor of Medicine, for his help in refining the English of the manuscript.
References Figure 14
(Case 3) Showing the healed flap.
1. Russel RC. Fingertip injuries. In: McCarthy J, editor. Plastic Surgery. 1st ed. Philadelphia: W.B. Saunders; 1990. p. 4477e98.
692 2. Edgerton BW, Beasley RW. Dorsal cross finger flaps. In: Strauch B, Vasconez LO, Hall Findlay EJ, editors. Grabb’s Encylopedia of Flaps. 1st ed. Boston: Little Brown & Co.; 1990. p. 905e10. 3. Curtis RM. Cross finger pedicle flap in hand surgery. Ann surgery 1957;145:650e5. 4. Gurdin M, Pangman J. The repair of surface defects of fingers by transdigital flaps. Plast Reconstr Surg 1950;5: 368e71. 5. Strauch B, Mouraw De. Arterial system of the finger. J Hand Surg 1990;15A:148e54. 6. Bene MD, Petrolati M, Raimond P, et al. Reverse dorsal digital island flap. Plast Reconstr Surg 1994;93:552e7.
S. Mishra, S. Manisundaram 7. Niranjan NS, Armstrong JR. A homodigital reverse pedicle island flap in soft tissue reconstruction of the finger and the thumb. J Hand Surg (British & European) 1994;19B:135e41. 8. Cohen BE, Cronin ED. An innervated cross finger flap for fingertip reconstruction. Plast Reconstr Surg 1983;72: 688e97. 9. Markley JM, Littler JW. Digital neurovascular island skin flap. In: Strauch B, Vasconez LO, Hall-Findlay EJ, editors. Grabb’s Encyclopedia of Flaps. 1st ed. Boston: Little Brown & Co; 1990. p. 887e91. 10. Venkataswami R. Staged neurovascular island skin flap from the middle finger to the thumb tip. In: Strauch B, Vasconez LO, Hall-Findlay EJ, editors. Grabb’s Encyclopedia of Flaps. 1st ed. Boston: Little Brown & Co; 1990. p. 892e4.