Review Article
Fingertip Injuries: An Update on Management Abstract Donald H. Lee, MD Megan E. Mignemi, MD Samuel N. Crosby, MD
From Vanderbilt Orthopaedics, Nashville, TN. Dr. Lee or an immediate family member has received royalties, research or institutional support, and nonincome support (such as equipment or services), commercially derived honoraria, or other non-research–related funding (such as paid travel) from, and serves as a paid consultant to, Biomet, and serves as a board member, owner, officer, or committee member of the American Academy of Orthopaedic Surgeons and the American Society for Surgery of the Hand. Dr. Crosby or an immediate family member has stock or stock options held in Pfizer and has received research or institutional support from Acumed, Smith & Nephew, Synthes, and Hand Innovations. Neither Dr. Mignemi nor any immediate family member has received anything of value from or has stock or stock options held in a commercial company or institution related directly or indirectly to the subject of this article. J Am Acad Orthop Surg 2013;21: 756-766 http://dx.doi.org/10.5435/ JAAOS-21-12-756 Copyright 2013 by the American Academy of Orthopaedic Surgeons.
756
Injuries to the fingertip are common. The goal of treatment is restoration of a painless, functional digit with protective sensation. The amount of soft-tissue loss, the integrity of the nail bed, and the age and physical demands of the patient should be considered when selecting a treatment method. Some new products are effective for management of injuries to the fingertip. The use of 2-octylcyanoacrylate for nail bed repair is faster than suture repair, with equivalent results reported. Dermal regeneration template is effective for coverage of digital injuries with exposed tendons or bones that lack peritenon or periosteum. Although fingertip replantation offers better functional results than does revision amputation, replantation is more technically demanding and requires longer recovery time. Complications associated with management of injuries to the fingertip include nail deformities, insensate digits, and painful neuromas.
I
njury to the fingertip (ie, injury distal to the insertion of the flexor and extensor tendons), is common, especially in young men who perform manual labor.1 The paucity of local soft tissue available for coverage of these injuries and the presence of the nail bed complicate management. The nail itself plays an important role in the normal function of the hand by protecting the fingertip, providing counterforce to assist with picking up small objects, and contributing to the tactile sensation of the fingertip.2-4 Management of injuries to the nail bed is based on the integrity of the nail plate and nail margin.5,6 In patients who sustain amputation of the fingertip, the nature of the injury and the physical demands of the patient should be considered when selecting a treatment method. For example, the presence of exposed bone helps to guide management. Treat-
ment options range from healing by secondary intention to flap coverage or replantation. Although replacement of the fingertip as a composite graft has been successful in children,7 replantation of the fingertip in adults often requires a vascular anastomosis to produce a viable fingertip.8,9
Anatomy The distal phalanx lies in the dorsal half of the fingertip. Its periosteum is connected to the dermis by multiple fibrous septae, which serve to anchor the skin to the bone. Volarly, the pulp of the fingertip is highly vascular and composed of fibroadipose tissue between the fibrous septae. These septae attach to the glabrous skin of the hand, tethering the two tissues together to assist with traction during grip. The perionychium comprises the
Journal of the American Academy of Orthopaedic Surgeons
Donald H. Lee, MD, et al
Figure 1
Illustration demonstrating the anatomy of the distal finger and nail bed and the Tamai and Allen classifications for distal amputations of the fingertip. The line through the lunula represents the divisions between Tamai zones I and II. DIPJ = distal interphalangeal joint
nail plate and the surrounding tissues, including the nail fold, eponychium, nail bed, hyponychium, and paronychium (Figure 1). The palmar floor of the nail fold is the germinal matrix, which is responsible for most nail growth. The germinal matrix extends from the nail fold to the lunula of the nail. The portion of the nail bed distal to the lunula is called the sterile matrix, which adds a small amount of thickness to the nail and is responsible for keeping the nail plate adhered to the nail fold. In the fingertip, the palmar digital arteries anastomose with each other just distal to the flexor digitorum profundus insertion, forming the distal transverse palmar arch. The arch gives off multiple branches that travel distally, with the central branches typically being larger (0.4 December 2013, Vol 21, No 12
to 0.6 mm in diameter) than other branches.10 The dorsal veins provide most of the venous outflow for the fingertip. For this reason, at least 4 mm of dorsal skin proximal to the nail plate is needed for adequate venous anastomosis.
Nail Bed Injuries Subungual hematoma, which is caused by bleeding under the nail plate, typically occurs after crush injury to the fingertip. In a study of 47 patients with subungual hematoma, Simon and Wolgin11 demonstrated that nail bed lacerations requiring repair occurred in 60% of patients when the subungual hematoma was >50% of the nail plate and in 95% of patients when there was an associ-
ated fracture of the distal phalanx. Consequently, the traditional approach to subungual hematomas that involve >25% to 50% of the nail plate was to remove the nail, inspect the sterile matrix, and repair any lacerations present.3,11 Equivalent outcomes have been reported in patients with an intact nail plate and injuries to the nail bed managed with trephination alone or trephination with nail removal and laceration repair, regardless of hematoma size or the presence of fracture.5,6 However, trephination alone is associated with substantially lower costs. In the setting of concomitant disruption of the nail or a nail margin with a subungual hematoma, the nail is commonly removed and lacerations are repaired. Although no evidence exists to support this approach, it seems to be prudent in the setting of a distal phalanx fracture to achieve adequate débridement of the open fracture. Classic repair of the nail bed consists of approximation of the lacerated edges with small-caliber (6.0 to 7.0) chromic or other absorbable suture (Figure 2). Once the repair is complete, the native nail plate may be replaced beneath the nail fold and allowed to fall out as the new nail plate grows. O’Shaughnessy et al12 found no difference in outcomes whether the nail plate was replaced or left off after repair. Recently, promising results have been achieved with the use of dermal adhesives for repair of nail bed laceration. In a randomized controlled trial, Strauss et al13 compared the efficacy of the adhesive 2-octylcyanoacrylate (Dermabond, Ethicon) with that of suture repair. The authors reported no difference in the results of both treatment groups, but the adhesive group required less time for repair than did the suture group. When this technique is used, it is critical to allow the adhesive to dry before replacing the nail plate to pre-
757
Fingertip Injuries: An Update on Management
Figure 2
A, Preoperative photograph demonstrating a complex nail bed injury. B, Intraoperative photograph demonstrating suture repair of a distal fingertip injury involving the nail bed. The skin laceration has been sutured with interrupted nylon sutures, and the nail bed has been repaired with interrupted chromic sutures. C, Postoperative photograph demonstrating nail replacement after nail bed repair.
vent it from sticking to the nail bed repair. When injury to the nail bed is associated with fracture, a crush injury to the tuft of the distal phalanx is the most common fracture. Although often highly comminuted, these fractures are stable secondary to the numerous fibrous septae of the surrounding soft tissue. Most of these fractures can be treated nonsurgically by immobilizing the finger in a splint (eg, stack, foam-laminated aluminum) for 3 to 4 weeks. Fractures of the distal phalanx that are substantially displaced and extend into the diaphysis and articular surface may require surgical fixation with a Kirschner wire or small screw.14 In a prospective study of 110 patients with fractures of the distal phalanx, DaCruz et al15 found that substantial morbidity was associated with these injuries. Six months postinjury, only 17% of patients with tuft fractures had fully recovered, with most patients reporting residual numbness, cold sensitivity, hyperesthesia, and difficulty with fine motor movement.
758
Management of Partial Fingertip Amputations Appropriate soft-tissue coverage of fingertip wounds should be determined by the nature of the injury and the physical demands and comorbidities of the patient. Management of injury to the fingertip varies from local wound care to complex reconstruction and replantation. For injuries with pulp loss and no distal bone exposure, management options include primary closure, healing by secondary intention, completion amputation, full-thickness skin grafting, and split-thickness skin grafting. Primary closure or healing by secondary intention are preferable for partial fingertip amputations when no bone is exposed and when adequate softtissue coverage is available volarly.16,17 Injury to the fingertip that involves the distal phalanx and is allowed to heal by secondary intention can lead to nail deformity in as many as 25% of patients.18 A hook nail deformity often develops in the setting of ex-
posed bone in the perionychium and a lack of adequate tissue volarly. Recovery of sensation after healing by secondary intention has been found to be superior to other surgical methods, and two-point discrimination approaches normal after healing.16,17 In the setting of significant softtissue loss on the volar aspect of the distal finger, completion amputation (ie, shortening and closure) is the simplest procedure with the quickest recovery in select patients. This can be performed in the emergency department with the patient under local anesthesia. The most important parts of this procedure are full ablation of the nail bed to prevent hook nail deformity and identification and transection of the digital nerves as far proximal to the level of amputation as possible to prevent formation of painful neuroma. Autogenous skin grafts can also be used to treat fingertip wounds; however, a well-vascularized recipient bed is required. The dorsal skin of the finger is thinner and looser than the volar skin, making it more amenable to skin grafting. The primary limitation of skin grafting is that it does not provide any subcutaneous tissue or padding and cannot be placed directly on bone or tendon, which often precludes its use for management of injuries to the fingertip. One advantage of full-thickness grafts is that they prevent wound contracture more than do splitthickness grafts. Full-thickness grafts require primary closure of the donor site and a well-débrided wound bed with meticulous hemostasis, whereas split-thickness graft donor sites can heal by secondary intention and are more forgiving with regard to preparation of the wound bed. Although preservation of finger length is important, flap reconstruction and replantation often require a prolonged period of immobilization and recovery. This may be unaccept-
Journal of the American Academy of Orthopaedic Surgeons
Donald H. Lee, MD, et al
able to the young, active patient who performs manual labor. The prolonged recovery period should be discussed in detail with the patient before treatment. Injuries with exposed bone and a lack of available soft tissue for coverage often require flap reconstruction if completion amputation is not desired by the patient. When a small area of coverage is needed, local flaps offer the lowest donor site morbidity. Local flaps are taken from a donor site with healthy tissue adjacent to the wound on the injured digit. Examples of local flaps include the Atasoy-Kleinert V-Y flap, the Kutler lateral V-Y flap, and the thenar advancement (ie, Moberg) flap.
Local Flaps Atasoy-Kleinert V-Y Flap This flap is best used for transverse or dorsal oblique amputations and can be used for all digits. Use of this flap is contraindicated in patients with volar oblique amputations and more tissue loss volarly. The distal edge of the wound is the base of the flap; the flap’s apex should extend to the distal interphalangeal crease (Figure 3). The skin and subcutaneous tissue are then incised, including the fibrous septa anchoring the pulp tissue to the bone. Damage to the neurovascular bundles should be avoided. The flap can be advanced up to 1 cm over the defect and secured with sutures, creating a Y-shaped repair. Kutler Lateral V-Y Flap The Kutler lateral V-Y flap is better suited for volar oblique amputations that have more tissue loss volarly than dorsally, but it can also be used for transverse amputations. The flap is similar to the Atasoy flap except that two flaps are used and the bases of the flaps are the radial and ulnar sides of the wound (Figure 4). Unlike December 2013, Vol 21, No 12
Figure 3
Illustrations demonstrating the Atasoy-Kleinert V-Y flap technique. A, The distal edge of the wound is the base of the flap and the apex of the flap should extend to the distal interphalangeal crease. The skin, subcutaneous tissue, and fibrous septa are incised (B) and the flap is secured over the defect with sutures (C).
the Atasoy flap, this flap provides only 3 to 4 mm of advancement.
Moberg Flap The Moberg flap is used for soft-tissue defects of the thumb and can be used when a V-Y advancement flap cannot provide adequate coverage of the defect and the defect measures
Fingertip Injuries: An Update on Management Abstract Donald H. Lee, MD Megan E. Mignemi, MD Samuel N. Crosby, MD
From Vanderbilt Orthopaedics, Nashville, TN. Dr. Lee or an immediate family member has received royalties, research or institutional support, and nonincome support (such as equipment or services), commercially derived honoraria, or other non-research–related funding (such as paid travel) from, and serves as a paid consultant to, Biomet, and serves as a board member, owner, officer, or committee member of the American Academy of Orthopaedic Surgeons and the American Society for Surgery of the Hand. Dr. Crosby or an immediate family member has stock or stock options held in Pfizer and has received research or institutional support from Acumed, Smith & Nephew, Synthes, and Hand Innovations. Neither Dr. Mignemi nor any immediate family member has received anything of value from or has stock or stock options held in a commercial company or institution related directly or indirectly to the subject of this article. J Am Acad Orthop Surg 2013;21: 756-766 http://dx.doi.org/10.5435/ JAAOS-21-12-756 Copyright 2013 by the American Academy of Orthopaedic Surgeons.
756
Injuries to the fingertip are common. The goal of treatment is restoration of a painless, functional digit with protective sensation. The amount of soft-tissue loss, the integrity of the nail bed, and the age and physical demands of the patient should be considered when selecting a treatment method. Some new products are effective for management of injuries to the fingertip. The use of 2-octylcyanoacrylate for nail bed repair is faster than suture repair, with equivalent results reported. Dermal regeneration template is effective for coverage of digital injuries with exposed tendons or bones that lack peritenon or periosteum. Although fingertip replantation offers better functional results than does revision amputation, replantation is more technically demanding and requires longer recovery time. Complications associated with management of injuries to the fingertip include nail deformities, insensate digits, and painful neuromas.
I
njury to the fingertip (ie, injury distal to the insertion of the flexor and extensor tendons), is common, especially in young men who perform manual labor.1 The paucity of local soft tissue available for coverage of these injuries and the presence of the nail bed complicate management. The nail itself plays an important role in the normal function of the hand by protecting the fingertip, providing counterforce to assist with picking up small objects, and contributing to the tactile sensation of the fingertip.2-4 Management of injuries to the nail bed is based on the integrity of the nail plate and nail margin.5,6 In patients who sustain amputation of the fingertip, the nature of the injury and the physical demands of the patient should be considered when selecting a treatment method. For example, the presence of exposed bone helps to guide management. Treat-
ment options range from healing by secondary intention to flap coverage or replantation. Although replacement of the fingertip as a composite graft has been successful in children,7 replantation of the fingertip in adults often requires a vascular anastomosis to produce a viable fingertip.8,9
Anatomy The distal phalanx lies in the dorsal half of the fingertip. Its periosteum is connected to the dermis by multiple fibrous septae, which serve to anchor the skin to the bone. Volarly, the pulp of the fingertip is highly vascular and composed of fibroadipose tissue between the fibrous septae. These septae attach to the glabrous skin of the hand, tethering the two tissues together to assist with traction during grip. The perionychium comprises the
Journal of the American Academy of Orthopaedic Surgeons
Donald H. Lee, MD, et al
Figure 1
Illustration demonstrating the anatomy of the distal finger and nail bed and the Tamai and Allen classifications for distal amputations of the fingertip. The line through the lunula represents the divisions between Tamai zones I and II. DIPJ = distal interphalangeal joint
nail plate and the surrounding tissues, including the nail fold, eponychium, nail bed, hyponychium, and paronychium (Figure 1). The palmar floor of the nail fold is the germinal matrix, which is responsible for most nail growth. The germinal matrix extends from the nail fold to the lunula of the nail. The portion of the nail bed distal to the lunula is called the sterile matrix, which adds a small amount of thickness to the nail and is responsible for keeping the nail plate adhered to the nail fold. In the fingertip, the palmar digital arteries anastomose with each other just distal to the flexor digitorum profundus insertion, forming the distal transverse palmar arch. The arch gives off multiple branches that travel distally, with the central branches typically being larger (0.4 December 2013, Vol 21, No 12
to 0.6 mm in diameter) than other branches.10 The dorsal veins provide most of the venous outflow for the fingertip. For this reason, at least 4 mm of dorsal skin proximal to the nail plate is needed for adequate venous anastomosis.
Nail Bed Injuries Subungual hematoma, which is caused by bleeding under the nail plate, typically occurs after crush injury to the fingertip. In a study of 47 patients with subungual hematoma, Simon and Wolgin11 demonstrated that nail bed lacerations requiring repair occurred in 60% of patients when the subungual hematoma was >50% of the nail plate and in 95% of patients when there was an associ-
ated fracture of the distal phalanx. Consequently, the traditional approach to subungual hematomas that involve >25% to 50% of the nail plate was to remove the nail, inspect the sterile matrix, and repair any lacerations present.3,11 Equivalent outcomes have been reported in patients with an intact nail plate and injuries to the nail bed managed with trephination alone or trephination with nail removal and laceration repair, regardless of hematoma size or the presence of fracture.5,6 However, trephination alone is associated with substantially lower costs. In the setting of concomitant disruption of the nail or a nail margin with a subungual hematoma, the nail is commonly removed and lacerations are repaired. Although no evidence exists to support this approach, it seems to be prudent in the setting of a distal phalanx fracture to achieve adequate débridement of the open fracture. Classic repair of the nail bed consists of approximation of the lacerated edges with small-caliber (6.0 to 7.0) chromic or other absorbable suture (Figure 2). Once the repair is complete, the native nail plate may be replaced beneath the nail fold and allowed to fall out as the new nail plate grows. O’Shaughnessy et al12 found no difference in outcomes whether the nail plate was replaced or left off after repair. Recently, promising results have been achieved with the use of dermal adhesives for repair of nail bed laceration. In a randomized controlled trial, Strauss et al13 compared the efficacy of the adhesive 2-octylcyanoacrylate (Dermabond, Ethicon) with that of suture repair. The authors reported no difference in the results of both treatment groups, but the adhesive group required less time for repair than did the suture group. When this technique is used, it is critical to allow the adhesive to dry before replacing the nail plate to pre-
757
Fingertip Injuries: An Update on Management
Figure 2
A, Preoperative photograph demonstrating a complex nail bed injury. B, Intraoperative photograph demonstrating suture repair of a distal fingertip injury involving the nail bed. The skin laceration has been sutured with interrupted nylon sutures, and the nail bed has been repaired with interrupted chromic sutures. C, Postoperative photograph demonstrating nail replacement after nail bed repair.
vent it from sticking to the nail bed repair. When injury to the nail bed is associated with fracture, a crush injury to the tuft of the distal phalanx is the most common fracture. Although often highly comminuted, these fractures are stable secondary to the numerous fibrous septae of the surrounding soft tissue. Most of these fractures can be treated nonsurgically by immobilizing the finger in a splint (eg, stack, foam-laminated aluminum) for 3 to 4 weeks. Fractures of the distal phalanx that are substantially displaced and extend into the diaphysis and articular surface may require surgical fixation with a Kirschner wire or small screw.14 In a prospective study of 110 patients with fractures of the distal phalanx, DaCruz et al15 found that substantial morbidity was associated with these injuries. Six months postinjury, only 17% of patients with tuft fractures had fully recovered, with most patients reporting residual numbness, cold sensitivity, hyperesthesia, and difficulty with fine motor movement.
758
Management of Partial Fingertip Amputations Appropriate soft-tissue coverage of fingertip wounds should be determined by the nature of the injury and the physical demands and comorbidities of the patient. Management of injury to the fingertip varies from local wound care to complex reconstruction and replantation. For injuries with pulp loss and no distal bone exposure, management options include primary closure, healing by secondary intention, completion amputation, full-thickness skin grafting, and split-thickness skin grafting. Primary closure or healing by secondary intention are preferable for partial fingertip amputations when no bone is exposed and when adequate softtissue coverage is available volarly.16,17 Injury to the fingertip that involves the distal phalanx and is allowed to heal by secondary intention can lead to nail deformity in as many as 25% of patients.18 A hook nail deformity often develops in the setting of ex-
posed bone in the perionychium and a lack of adequate tissue volarly. Recovery of sensation after healing by secondary intention has been found to be superior to other surgical methods, and two-point discrimination approaches normal after healing.16,17 In the setting of significant softtissue loss on the volar aspect of the distal finger, completion amputation (ie, shortening and closure) is the simplest procedure with the quickest recovery in select patients. This can be performed in the emergency department with the patient under local anesthesia. The most important parts of this procedure are full ablation of the nail bed to prevent hook nail deformity and identification and transection of the digital nerves as far proximal to the level of amputation as possible to prevent formation of painful neuroma. Autogenous skin grafts can also be used to treat fingertip wounds; however, a well-vascularized recipient bed is required. The dorsal skin of the finger is thinner and looser than the volar skin, making it more amenable to skin grafting. The primary limitation of skin grafting is that it does not provide any subcutaneous tissue or padding and cannot be placed directly on bone or tendon, which often precludes its use for management of injuries to the fingertip. One advantage of full-thickness grafts is that they prevent wound contracture more than do splitthickness grafts. Full-thickness grafts require primary closure of the donor site and a well-débrided wound bed with meticulous hemostasis, whereas split-thickness graft donor sites can heal by secondary intention and are more forgiving with regard to preparation of the wound bed. Although preservation of finger length is important, flap reconstruction and replantation often require a prolonged period of immobilization and recovery. This may be unaccept-
Journal of the American Academy of Orthopaedic Surgeons
Donald H. Lee, MD, et al
able to the young, active patient who performs manual labor. The prolonged recovery period should be discussed in detail with the patient before treatment. Injuries with exposed bone and a lack of available soft tissue for coverage often require flap reconstruction if completion amputation is not desired by the patient. When a small area of coverage is needed, local flaps offer the lowest donor site morbidity. Local flaps are taken from a donor site with healthy tissue adjacent to the wound on the injured digit. Examples of local flaps include the Atasoy-Kleinert V-Y flap, the Kutler lateral V-Y flap, and the thenar advancement (ie, Moberg) flap.
Local Flaps Atasoy-Kleinert V-Y Flap This flap is best used for transverse or dorsal oblique amputations and can be used for all digits. Use of this flap is contraindicated in patients with volar oblique amputations and more tissue loss volarly. The distal edge of the wound is the base of the flap; the flap’s apex should extend to the distal interphalangeal crease (Figure 3). The skin and subcutaneous tissue are then incised, including the fibrous septa anchoring the pulp tissue to the bone. Damage to the neurovascular bundles should be avoided. The flap can be advanced up to 1 cm over the defect and secured with sutures, creating a Y-shaped repair. Kutler Lateral V-Y Flap The Kutler lateral V-Y flap is better suited for volar oblique amputations that have more tissue loss volarly than dorsally, but it can also be used for transverse amputations. The flap is similar to the Atasoy flap except that two flaps are used and the bases of the flaps are the radial and ulnar sides of the wound (Figure 4). Unlike December 2013, Vol 21, No 12
Figure 3
Illustrations demonstrating the Atasoy-Kleinert V-Y flap technique. A, The distal edge of the wound is the base of the flap and the apex of the flap should extend to the distal interphalangeal crease. The skin, subcutaneous tissue, and fibrous septa are incised (B) and the flap is secured over the defect with sutures (C).
the Atasoy flap, this flap provides only 3 to 4 mm of advancement.
Moberg Flap The Moberg flap is used for soft-tissue defects of the thumb and can be used when a V-Y advancement flap cannot provide adequate coverage of the defect and the defect measures
