Fingertip Injuries: Evaluation and Treatment

Paul R. Fassler, MD

Abstract

The primary goal of treatment of an injury to the fingertip is a painless fingertip of the distal phalanx and consists of with durable and sensate skin. Knowledge of fingertip anatomy and the available the sterile and germinal matrices. techniques of treatment is essential. For injuries with soft-tissue loss and no ex- The germinal matrix is located prox- posed bone, healing by secondary intention or skin grafting is the method of choice. imally and forms the ventral floor of When bone is exposed and sufficient nail matrix remains to provide a stable and the nail fold. Its distal margin is de- adherent nail plate, coverage with a local advancement flap should be considered. fined by the white semicircular area If the angle of amputation does not permit local flap coverage, a regional flap near the base of the nail, known as (cross-finger or thenar) may be indicated. If the amputation is more proximal or the lunula. The germinal matrix if the patient is not a candidate for a regional flap because of advanced age, os- produces 90% of the thickness of the teoarthritis, or other systemic condition, shortening with primary closure is pre- nail plate; however, the nail plate is ferred. Composite reattachment of the amputated tip may be successful in young not adherent to the germinal matrix. children. The outcome of nail-bed injuries is most dependent on the severity of in- The sterile matrix, the portion of the jury to the germinal matrix. nail bed distal to the lunula, is ad- J Am Acad Orthop Surg 1996;4:84-92 herent to the nail plate and con- tributes little to its thickness. The dorsal skin over the nail fold is called the nail wall. The distal mar- Fingertip injuries, defined as those justified for some injuries of the gin of the nail wall, which adheres distal to the insertion of the flexor thumb, including those in children. to the nail plate, is called the epony- and extensor tendons, are the most chium. The matrix tissue that forms common injuries of the hand. Al- the dorsal roof of the nail fold pro- though maintenance of length, Anatomy of the Fingertip vides shine to the nail plate. preservation of the nail, and appear- ance are important, the primary goal Knowledge of fingertip anatomy1 is of treatment is a painless fingertip essential for optimal treatment of in- General Principles of with durable and sensate skin. Con- juries. The skin covering the pulp of Evaluation and Treatment siderable hand dysfunction results the finger is very durable and has a when a painful fingertip causes the thick epidermis with deep papillary Evaluation of a patient with a finger- patient to exclude the digit from use. ridges. The thick skin beneath the tip injury begins with taking a history Treatment must be individualized distal free edge of the nail plate is of the mechanism of injury and im- on the basis of many patient-related called the hyponychium. The pulp factors and specific wound charac- consists of fibrofatty tissue that is teristics. Methods of treatment in- stabilized by fibrous septa extending Dr. Fassler is Clinical Instructor, Department of clude healing by secondary from the dermis to the periosteum of Orthopedics, University of Cincinnati College of intention, skin grafting, shortening the distal phalanx. Medicine. of the bone and primary closure, and The nail complex, or perionych- coverage with a local or regional ium, includes the nail plate, the nail Reprint requests: Dr. Fassler, Cincinnati Hand flap. Composite reattachment bed, and the surrounding skin on Surgery Consultants, 2800 Winslow Avenue, Suite 401, Cincinnati, OH 45206. should be considered for fingertip the dorsum of the fingertip (paro- amputations in young children. Al- nychium) (Fig. 1). The nail bed is Copyright 1996 by the American Academy of Or- though microsurgical replantation is adherent to the very thin perios- thopaedic Surgeons. not indicated in most cases, it may be teum over the distal two thirds or so

84 Journal of the American Academy of Orthopaedic Surgeons Paul R. Fassler, MD

cal options are discussed in the fol- Insertion of extensor tendon Nail wall lowing sections. Nail bed

Soft-Tissue Loss Without Dorsal roof Nail fold Exposed Bone Hyponychium Ventral floor Distal interphalangeal joint Appropriate treatment for loss of skin or pulp tissue without exposed bone is either to perform a skin graft or to allow the wound to heal by sec- Periosteum ondary intention. Controversy exists Fig. 1 The anatomy of the nail bed in sagittal section. as to which is method is better. Most agree that smaller wounds (those no larger than 1 cm2) should be treated nonoperatively by the open method; portant patient-related factors, such field is essential to allow inspection however, the size of the defect rela- as age, gender, handedness, occupa- and repair of the wound. A Penrose tive to the size of the finger must be tion, avocation, and history of previ- drain clamped around the base of the taken into consideration. ous hand problems and systemic finger is convenient, but other de- The primary advantage of the open diseases. A complete hand examina- vices, such as a pneumatic digital technique is its simplicity. Several au- tion includes assessment of the skin, sleeve, a wrist tourniquet, or a blood thors have reported superior results, vascularity, neurologic function, and pressure cuff placed around the fore- high patient satisfaction, and few flexor and extensor tendon function. arm, can also be used. The wound complications with this method.2,3 The injury site is inspected with spe- should be closely inspected after it Complete healing usually takes 3 to 5 cific attention to the characteristics of has been thoroughly irrigated and weeks and occurs by wound contrac- the wound. Radiographs of the fin- debrided of all nonviable and conta- tion and epithelialization. About 7 to ger are obtained to assess the extent minated soft tissue. It is critical to re- 10 days after the injury, the patient is of bone injury. Intravenous anti- member that in the severely crushed instructed to begin soaking the finger biotics are given to patients with a fingertip, the full extent of the injury in a warm water–peroxide solution fracture, and appropriate tetanus may not be evident until the wound once a day and to apply a light ban- prophylaxis is provided. has been meticulously debrided, dage and fingertip protector. Range- Once the patient and wound have which then necessitates modification of-motion exercises are encouraged. been completely assessed, a treat- of the original treatment plan. When the wound is completely epi- ment plan is formulated. If more The specific wound characteris- thelialized, a home program of desen- than one option is available, the ad- tics determine which method of sitization is initiated. vantages and disadvantages of each treatment is optimal for a given Larger wounds treated nonopera- should be discussed with the pa- patient. It is important to know tively heal with a thin layer of epithe- tient, and the simplest method that whether there is loss of skin or pulp lium that is not very durable, and accomplishes the desired result tissue and the amount of such loss, application of a skin graft should be should be selected. as well as whether there is exposed considered. Skin grafts applied to the Many fingertip injuries can be bone, a distal phalangeal fracture, palmar surface of the fingertip should managed in a well-equipped emer- or injury to the nail bed or peri- be full thickness because they contract gency department, but complex re- onychial tissue. In the case of am- less, are more durable and less tender, gional flaps are more appropriately putation, it is important to establish and achieve better sensibility than treated in a formal operating room. A the level and angle of injury. For split grafts. The hypothenar area is digital block placed at the level of the wounds with no soft-tissue loss, the preferred donor site, as it is con- metacarpal head is a convenient simple closure is all that is needed. venient and the skin is durable and an method of obtaining analgesia. A Viable skin flaps are loosely su- excellent color match, similar in qual- wrist block can be used when more tured, and a splint is applied if a ity to the skin of the pulp.4 than one digit is injured. The entire fracture is present. The skin graft is taken from the hand and forearm are prepared and The treatment of specific types of hairless area of the ulnar border of draped in sterile fashion. A bloodless injuries and the use of various surgi- the hand. The width of the graft

Vol 4, No 2, March/April 1996 85 Fingertip Injuries can be as much as 2 cm. The donor sterile matrix remains (less than 5 brought over the end of the bone and site is closed primarily. The graft is mm) to produce an adherent, stable sutured to the dorsal skin. If the an- sutured over the defect, with a few nail.6 Patients who are of advanced gle of the amputation is oblique in sutures left long so that a moist cot- age or who have a systemic condi- the sagittal plane, the side with the ton ball can be secured over the tion and in whom, therefore, a re- long skin flap is used to cover the graft to help maintain coaptation gional flap is contraindicated should bone. Excess skin (e.g., dog-ears) with the underlying tissue. The undergo a revision amputation usually needs to be trimmed to ob- cotton ball is removed after about 7 when open treatment, skin grafting, tain satisfactory contour and ap- days, and range-of-motion exer- or local flap coverage is not possible. pearance. cises are initiated. Skin grafts The remaining nail matrix must should not be used indiscrimi- be ablated to prevent formation of ir- nately, as they can be associated ritating nail remnants. To gain ac- Local Flaps with significant morbidity, such as cess to the most proximal portion of tenderness, hypesthesia, decreased the germinal matrix, the nail wall is A local flap is one in which the trans- sensibility, infection, failure, and reflected proximally by making inci- ferred tissue is confined to the in- donor-site complaints. sions on each side of it, extending jured digit, with at least one side of from the eponychium. If the flexor the flap adjacent to the defect. The and extensor tendon insertions can- advantages are that they can be used Soft-Tissue Loss With not be preserved in the revision, the in patients of any age, they preserve Exposed Bone distal interphalangeal joint should length, the donor defect does not re- be disarticulated, as there is no ad- quire a skin graft, and the trans- When bone is exposed, satisfactory vantage in preserving a small stump posed tissue is similar in quality, soft-tissue coverage must be obtained. of distal phalanx. texture, and color to that of the recip- There is almost never sufficient local Distal traction is applied to the ient site. An early range-of-motion tissue available to close primarily, and profundus and extensor tendons, program can be started. Use of these attempts to do so may result in skin which are then transected and al- flaps requires judgment and exper- necrosis, a painful fingertip, and pro- lowed to retract. The prominent tise and should not be attempted by longed morbidity. Nonmicrovascular volar condyles of the head of the the inexperienced. Figure 2 shows reattachment of the fingertip as a com- middle phalanx are removed with a the various angles of amputation. posite graft is not recommended in rongeur, and the palmar plate and adults. It has been reported to be suc- collateral ligaments are excised to V-Y Flap cessful in a few patients,5 but it fre- improve the contour. To prevent the For transverse or dorsal oblique quently results in failure. Treatment occurrence of a painful neuroma, it (more tissue loss dorsally than by the open method after the bone has is essential that the digital nerves be volarly) amputations, the triangu- been shortened below the level of the identified, mobilized for a short dis- lar volar, or V-Y, flap (Fig. 3) is an skin may result in a satisfactory out- tance, placed under slight tension, ideal method of treatment.7 It can come; however, it is associated with and transected about 1 cm from the be used for all digits, including the an unacceptable incidence of nail- wound edge. The palmar skin is thumb. The critical factor that plate deformities. Coverage by local or regional flaps or shortening of the bone with primary closure is usually necessary for these types of wounds. The choice of procedure is determined primarily on the basis of the level and angle of the amputation and the age Fig. 2 Angles and levels of amputation. A, Volar and sex of the patient. oblique with no exposed bone. B, Volar oblique with exposed bone. C, Transverse with exposed bone. D, Dor- Revision Amputation sal oblique with exposed bone. Shortening and primary closure of fingertip amputations is indicated in adults of any age when not enough

86 Journal of the American Academy of Orthopaedic Surgeons Paul R. Fassler, MD

mal or nearly normal sensibility of the fingertip and superb restoration of contour and padding.

Kutler Flap This flap is most appropriate for distal transverse amputations. Kutler8 described the use of dual triangular flaps advanced from the sides of the fingertip. Triangular flaps are designed on each side of the tip, with the bases being the dis- tal edge of the wound and the A B C apices more proximal. After inci- sion of the skin and subcutaneous tissue, the flaps are advanced, without undermining, over the end of the bone and sutured to each other. The disadvantage of this technique is that the flaps are small and may be difficult to advance, with the result that closure cannot D E F be obtained without tension.

Fig. 3 Triangular volar advancement flap. A, Bone is trimmed even with skin and distal edge of nail bed. B, Flap is designed with base at distal margin of wound and apex in mid- Regional Flaps line of distal interphalangeal crease. C, Flap is mobilized. D, Flap is advanced distally over end of bone and sutured to distal margin of nail bed. E and F, Volar skin is sutured. The two most commonly used re- gional flaps, the cross-finger flap and must be assessed is whether be divided. From the distal aspect of the thenar flap, can be used for simi- enough palmar tissue is available the wound, a No. 15 knife blade is lar defects involving the fingertips. for distal advancement. The distal swept tangentially along the volar as- They are employed to preserve edge of the flap can be advanced pect of the bone to divide the septal length and obtain coverage of ampu- only about 1 cm. Not appropriate attachments to the periosteum. The tations with a volar oblique angle and for treatment with this flap are am- mobilized tissue is then advanced amputations too proximal to allow putations that are too proximal and over the end of the bone and sutured performance of a local flap, as well as those with more tissue loss volarly to the distal edge of the nail bed with to replace substantial loss of pulp tis- than dorsally (volar oblique), as 5-0 nylon sutures. The tourniquet can sue. In patients with more than one there is not enough tissue for ad- be removed at this point to check the fingertip injury, multiple cross-finger vancement. vascularity of the flap. If capillary re- flaps or a combination of cross-finger The flap is designed with the dis- fill is poor, it is usually because there and thenar flaps may be appropriate.9 tal edge of the wound as the base of has been inadequate mobilization The main disadvantage of these a triangular flap. The apex is a point and the vessels are stretched. flaps is that their use involves a two- in the midline of the distal interpha- Once it has been ascertained that stage procedure requiring division langeal crease. The nail bed and the flap has been properly mobilized of the flap. Because prolonged im- bone should be trimmed even with and there is good capillary refill, the mobilization may result in stiffness, each other. The skin and subcuta- remaining edges of the flap can be su- some consider patient age greater neous tissue are then incised, with tured. The skin edges of the flap need than about 40 to be a relative con- great care being taken not to damage not be sutured too tightly, as this may traindication to their use. However, the neurovascular bundles. compromise blood flow. Any subcu- Melone et al10 used the thenar flap in To adequately mobilize the flap, taneous tissue protruding between patients over the age of 50 with no all the fibrous septa that anchor the the skin edges will heal by secondary resultant stiffness in digits with pulp tissue to the distal phalanx must intention. Patients usually have nor- trauma isolated to the fingertip.

Vol 4, No 2, March/April 1996 87 Fingertip Injuries

These flaps are contraindicated in patients with osteophytes or arthri- tis in the involved digits and in pa- tients with systemic conditions, such as rheumatoid arthritis, diabetes, and vasospastic disorders.9 The cross-finger flap leaves a dor- A sal donor-site scar that may be unap- pealing, especially to female B patients. In dark-skinned persons, transfer of the darker dorsal skin to the lighter fingertip pad may be ob- jectionable. The thenar-flap donor site is less conspicuous and may be better accepted by female and dark- skinned patients. Postoperatively, the hand is sup- ported in a bulky dressing and splint for comfort. Uninjured digits can be left free to exercise. Flap division is performed with the use of local anes- thesia about 12 to 14 days after the initial procedure. Delaying division C of the flap much beyond 14 days in- Fig. 4 A, Volar oblique amputation with exposed bone. B, A cross-finger flap is elevated creases the risk of joint stiffness. Su- from the dorsal aspect of the donor digit. C, Flap is sutured to defect. turing of the cut edge of the flap at the recipient site at the time of division is not recommended, as tension from sutures may cause marginal necrosis. Variations in the design of the sensibility to the skin over the mid- Local wound care of the small open cross-finger flap can be made depend- dle phalanx is transected proximally areas and an aggressive range-of-mo- ing on the location and size of the de- and sutured to the proper digital tion program are instituted immedi- fect. The flap can be based proximally, nerve of the injured digit. ately on division of the flap. distally, or laterally. A proximally based cross-finger flap can also be Thenar Flap Cross-Finger Flap raised over the dorsum of the thumb The thenar flap can be used for The standard cross-finger flap is for coverage of defects on the radial any fingertip, but sometimes the outlined as a rectangle over the mid- side of the tip of the index finger. small finger can be difficult to posi- dle phalanx of the donor digit, with Kleinert et al11 reported satisfac- tion comfortably. Stiffness of the the hinge side adjacent to the injured tory recovery of sensibility (two- proximal interphalangeal joint and finger9 (Fig. 4). The longitudinal axis point discrimination of 8 mm or tenderness of the donor site have of the hinge runs along the midaxial better) in 70% of 56 patients in whom been concerns with this flap; how- line. The skin is incised on three cross-finger flaps were used. The av- ever, Melone et al10 reported few sides, and the incision is carried erage two-point discrimination re- complications in 150 patients. through the subcutaneous tissue. As ported by Nishikawa and Smith12 The most important technical con- the flap is raised, it is imperative that was about 10 mm, and many of their sideration is the location of the flap on the paratenon of the extensor tendon patients had impaired tactile gnosia. the thenar eminence. It should be de- be preserved. The flap is reflected Despite the abnormalities in sensibil- signed high on the thenar eminence, on its hinge, and the injured finger- ity, most patients in both studies with the radial border parallel and ad- tip is placed on the subcutaneous were very satisfied with the out- jacent to the metacarpophalangeal surface of the flap and sutured. A come. Cohen and Cronin13 modified joint crease. Placing it too close to the full-thickness skin graft from the the standard cross-finger flap to im- midpalm has been associated with groin or elsewhere is applied to the prove sensibility. The dorsal sensory debilitating donor-site tenderness. donor defect. nerve of the donor digit that supplies The base of the flap is located proxi-

88 Journal of the American Academy of Orthopaedic Surgeons Paul R. Fassler, MD mally. Flap width and length are de- sions are made on both sides of the finger usually provides satisfactory termined on the basis of the size of the thumb, extending from the injury padding of the thumb and adequate defect. The flap can be as wide as 2 cm site to the metacarpophalangeal sensibility. The hinge of the flap is and should be 1.5 times as wide as the crease. The entire volar skin flap, placed on the radial side of the prox- defect so as to restore the normal containing both neurovascular bun- imal phalangeal segment of the in- rounded contour to the tip. dles, is dissected from the flexor ten- dex finger. Innervation of the The skin is elevated with its un- don sheath from distal to proximal. cross-finger flap from the index fin- derlying subcutaneous tissue, with The flap is advanced over the bone. ger can be augmented by transpos- care being taken not to damage the Flexion of the interphalangeal joint ing branches of the dorsal sensory radial digital nerve of the thumb. may be necessary for the flap to branch of the radial nerve at the time Before the flap is sutured to the de- reach the tip; however, a flexion con- of attachment of the flap.16 In addi- fect, a full-thickness skin graft is ap- tracture of the interphalangeal joint tion to transposing those branches, plied to the donor area from the may develop if it is positioned with Hastings17 performed a neurorrha- non-hair-bearing area of the groin, too much flexion. The flap can be phy of the dorsal sensory branch of the palmar aspect of the wrist, or the mobilized a greater distance, thus re- the radial digital nerve of the index hypothenar area. If the donor area is quiring less interphalangeal joint finger to the lacerated ulnar digital not too wide, it is sometimes possi- flexion, if a transverse incision is nerve of the thumb. Thumb defects ble to perform a primary closure. made between the two longitudinal can also be covered by dorsal or pal- The finger is positioned with the incisions near the metacarpopha- mar cross-finger flaps from digits metacarpophalangeal and distal in- langeal crease and the proximal de- other than the index finger.18,19 terphalangeal joints flexed as much fect is covered with a full-thickness as possible to decrease the amount of skin graft. First Dorsal Metacarpal flexion required at the proximal in- Artery–Island Pedicle Flap terphalangeal joint, and the flap is Cross-Finger Flap From Index This is an excellent flap that is then sutured to the defect. A well- Finger performed in one stage and can in- molded dressing and splint are ap- For loss of more than two thirds clude branches of the dorsal sensory plied, permitting range of motion of of the pulp tissue, a cross-finger flap branch of the radial nerve.20,21 It is the uninjured fingers. from the dorsal aspect of the index based on the first dorsal metacarpal

Injury of the Thumb

The principles of management of in- juries of the thumb tip are similar to those for other digits. However, the importance of preservation of length and restoration of sensibility is mag- nified. Although function of the thumb is usually satisfactory when the thumb has been shortened to the level of the interphalangeal joint, the availability of local and regional flaps allows preservation of length in most cases.

Moberg Advancement Flap For soft-tissue defects that cannot be restored with a V-Y flap and for those measuring no more than about 2 cm in length, the Moberg advance- ment flap14,15 (Fig. 5) is the procedure Fig. 5 Moberg advancement pedicle flap for thump-tip injury. Midaxial incisions are out- lined radially (A) and ulnarly (B). C, A flap containing both neurovascular bundles is raised. of choice because it preserves length D, Flap is advanced and sutured. Note interphalangeal joint flexion. and tactile gnosia. Midaxial inci-

Vol 4, No 2, March/April 1996 89 Fingertip Injuries artery, which is a branch of the radial When no bone is exposed, I prefer hematomas, the nail plate should be artery. The skin over the dorsum of to treat fingertip injuries by the open removed to repair the nail bed. the proximal phalanx of the index method. For amputations through finger is elevated in a manner simi- the sterile-matrix region in which Lacerations lar to that for a standard cross-finger the distal segment is not available or Lacerations are repaired after re- flap but with incisions on all four is badly crushed, protruding bone is moval of the entire nail plate or at sides. An incision is extended prox- trimmed even with or just below the least enough to allow placement of imally over the dorsum of the first level of the soft tissue, and healing sutures. The nail plate is carefully web space, and a pedicle containing by secondary intention is allowed. separated from the nail matrix with the first dorsal metacarpal artery, the The bone should not be trimmed to a a Freer elevator. The wound is then subcutaneous veins, and branches of level more proximal than the distal irrigated and debrided, taking care the dorsal sensory branch of the ra- margin of the nail matrix, as a hook- that all matrix tissue is retained. dial nerve is isolated. The skin is- nail deformity may result. If the am- Fractures of the distal phalangeal land with the attached pedicle is putation is through the germinal shaft can usually be stabilized by transferred to the thumb defect and matrix and no distal segment is simply suturing the skin of the lat- sutured in place. The donor area is available, the nail matrix is ablated, eral nail folds and the nail bed. If the covered with a full-thickness skin the bone is shortened, and the fracture is unstable, it may displace, graft from the groin. wound is closed primarily or left to which will result in tenting of the heal by secondary intention. nail bed. Unstable fractures should Neurovascular-Island Pedicle If there is a clean, sharp amputa- be pinned with a Kirschner wire, Flap tion through any portion of the nail avoiding the distal interphalangeal The neurovascular-island flap, and the distal segment is available, joint if possible. Lacerations of the first described by Littler,22 requires the tip can be simply reattached as a skin and lateral nail folds should be the transfer of tissue from the ulnar composite graft. The upper age repaired with 5-0 nylon suture to side of the ring or middle finger limit for successful composite reat- stabilize the soft tissue. The nail bed across the palm to the thumb on its tachment has not yet been estab- is meticulously approximated with neurovascular pedicle. It is used to lished. absorbable 6-0 chromic or plain gut restore sensibility and padding to suture. Flaps of tissue that are too the ulnar side of the thumb pulp if small to accept sutures should be re- other methods have proved unsatis- Nail-Bed Injuries placed in their normal position. If factory. Because of the possibility of the laceration extends into the ger- mutilation of the donor digit and Injuries of the nail bed are varied minal matrix, the nail wall should be availability of superior flaps, the use and include subungual hematomas, reflected proximally by making an of this flap is very limited and simple and complex lacerations, and incision on each side of it, extending should not be the surgeon’s first avulsions of matrix tissue. It is im- from the eponychium. choice for regional coverage of acute portant that the nail bed be repaired After repair, the nail plate should thumb-tip injuries. with great attention to detail in order be placed back into the nail fold to to restore function and prevent an- prevent scar formation between the noying or unsightly deformities.24 ventral floor and the dorsal roof. If Fingertip Injuries in Loupe magnification is recom- the nail plate is not available, a piece Children mended, and the use of microinstru- of nonadherent gauze cut in the ments allows easier handling of the shape of the nail is a good substitute. Most crush- and avulsion-type fin- tissue and small needle. It can be left in place indefinitely, as gertip amputations in children can it will be pushed out as the new nail be managed by the open method. Subungual Hematomas regrows. Especially in children less than 2 Decompression of a subungual years of age, a relatively normal-ap- hematoma should be performed to Nail-Matrix Avulsions pearing fingertip can be formed, relieve pain if it involves no more When the proximal portion of the even when bone is exposed.23 Non- than 50% of the area of the nail.24 A nail plate has been avulsed from the microsurgical reattachment of the hole should be placed in the nail nail fold and lies on top of it, there is cleanly amputated fingertip as a plate over the hematoma with either always an associated nail-bed lacer- composite graft by suturing the skin a heated paper clip or an 18-gauge ation or avulsion of the germinal ma- and nail bed can also be successful. needle. For larger subungual trix from its proximal attachment

90 Journal of the American Academy of Orthopaedic Surgeons Paul R. Fassler, MD and a fracture or epiphyseal separa- Injuries of the Nail Wall tion. Proximal detachments or avul- sions of the germinal matrix must be Repair of the dorsal nail wall should be replaced into the nail fold (Fig. 6). accomplished in two layers, with the Three sutures, one at each corner use of 5-0 nylon sutures for the outer and one in the middle, are sufficient. skin and 6-0 chromic for the matrix of Each suture is passed from the out- the dorsal roof. In cases of avulsion of side to the inside of the nail fold, the nail wall, reconstruction is best per- through the proximal edge of the formed with a local rotation flap.27 If germinal matrix in a horizontal-mat- that is not possible, reconstruction of tress fashion, and back through the the nail wall can be accomplished with base of the nail fold, exiting dorsally. a reverse cross-finger flap.19,28 Shep- After all three sutures have been ard26 recommends the placement of a passed, the germinal matrix is split-thickness graft on the undersur- cinched into place by pulling proxi- face of the flap. mally on the sutures, which are tied over the dorsum of the nail fold. Injuries of the nail bed resulting Summary in loss of matrix tissue are the most difficult to treat and are the ones Fig. 6 A, Proximal detachment of the ger- For the treatment of fingertip in- minal matrix. B, Replacement into nail fold most likely to result in a permanent and repair with horizontal mattress sutures. juries, the decision-making process deformity.25 The detached nail plate should proceed from the simpler should be inspected for remnants of techniques to the more compli- the nail bed that can be used for re- cated. When no bone is exposed, pair. If available, the avulsed tissue An excellent result can be expected the open method is ideal for small can be carefully removed from the in about 90% of cases.26 or moderate-sized wounds, and nail plate with a scalpel and sutured Treatment of avulsion of germi- skin grafting should be considered in place as a full-thickness graft di- nal matrix with no available tissue for larger wounds. Distal trans- rectly on the distal phalanx. for replacement depends primarily verse and dorsal oblique amputa- Defects in the sterile matrix with on the size and width of the defect. tions with bone exposure can be no tissue available for repair should Shepard26 has used split-thickness treated with local tissue advance- be treated with a split-thickness germinal-matrix grafts from an adja- ment that preserves length. More nail-bed graft. The optimal donor cent area of undamaged germinal proximal and volar oblique ampu- site is an undamaged area of the matrix, full- or split-thickness grafts tations can be managed with a re- sterile matrix of the injured digit. from the great toe, and local bipedi- gional flap to preserve length if Other donor options are the nail bed cle or distally based nail-bed flaps. enough sterile matrix remains for a of an unsalvageable discarded digit The results of these methods of nail- stable nail and if there is no con- or the great toe. Split-thickness ster- bed replacement are unreliable, and traindication. Shortening and pri- ile matrix grafts are obtained by nail deformities may occur at the in- mary skin closure can be used for shaving the donor nail bed with a jury and donor sites. If the entire amputations not amenable to other scalpel blade. The graft must be nail bed has been completely or methods of treatment. The surgeon very thin (0.007 to 0.011 inch) to pre- nearly completely avulsed and the should be familiar with the advan- vent a deformity from occurring at distal phalanx remains, the best tages and disadvantages of all the the donor site. The graft is then su- treatment is the application of a available methods of treatment to tured to the surrounding nail bed. split-thickness skin graft. ensure high patient satisfaction.

Vol 4, No 2, March/April 1996 91 Fingertip Injuries

References 1. Zook EG: Anatomy and physiology of 11. Kleinert HE, McAlister CG, MacDonald 20. Foucher G, Braun JB: A new island flap the perionychium. Hand Clin 1990;6:1-7. CJ, et al: A critical evaluation of cross transfer from the dorsum of the index to 2. Chow SP, Ho E: Open treatment of fin- finger flaps. J Trauma 1974;14:756-763. the thumb. Plast Reconstr Surg 1979; gertip injuries in adults. J Hand Surg 12. Nishikawa H, Smith PJ: The recovery of 63:344-349. [Am] 1982;7:470-476. sensation and function after cross-finger 21. Sherif MM: First dorsal metacarpal 3. Louis DS, Palmer AK, Burney RE: Open flaps for fingertip injury. J Hand Surg artery flap in hand reconstruction: II. treatment of digital tip injuries. JAMA [Br] 1992;17:102-107. Clinical application. J Hand Surg [Am] 1980;244:697-698. 13. Cohen BE, Cronin ED: An innervated 1994;19:32-38. 4. Schenck RR, Cheema TA: Hypothenar cross-finger flap for fingertip recon- 22. Littler JW: Neurovascular skin island skin grafts for fingertip reconstruction. J struction. Plast Reconstr Surg 1983;72: transfer in reconstructive hand surgery, Hand Surg [Am] 1984;9:750-753. 688-697. in Wallace AB (ed): Transactions of the 5. Rose EH, Norris MS, Kowalski TA, et 14. Moberg E: Aspects of sensation in re- International Society of Plastic Surgeons. al: The “cap” technique: Nonmicrosur- constructive surgery of the upper ex- London: E & S Livingstone, 1960, pp gical reattachment of fingertip ampu- tremity. J Bone Joint Surg Am 1964; 175-178. tations. J Hand Surg [Am] 1989;14: 46:817-825. 23. Das SK, Brown HG: Management of 513-518. 15. Posner MA, Smith RJ: The advance- lost finger tips in children. Hand 6. Rosenthal EA: Treatment of fingertip ment pedicle flap for thumb injuries. J 1978;10:16-27. and nail bed injuries. Orthop Clin North Bone Joint Surg Am 1971;53:1618-1621. 24. Van Beek AL, Kassan MA, Adson MH, Am 1983;14:675-697. 16. Gaul JS Jr: Radial-innervated cross-fin- et al: Management of acute fingernail 7. Atasoy E, Ioakimidis E, Kasdan ML, et ger flap from index to provide sensory injuries. Hand Clin 1990;6:23-35. al: Reconstruction of the amputated fin- pulp to injured thumb. J Bone Joint Surg 25. Zook EG, Guy RJ, Russell RC: A study ger tip with a triangular volar flap: A Am 1969;51:1257-1263. of nail bed injuries: Causes, treatment, new surgical procedure. J Bone Joint 17. Hastings H II: Dual innervated index to and prognosis. J Hand Surg [Am] Surg Am 1970;52:921-926. thumb cross finger or island flap recon- 1984;9:247-252. 8. Kutler W: A new method for finger tip struction. Microsurgery 1987;8:168-172. 26. Shepard GH: Management of acute nail amputation. JAMA 1947;133:29-30. 18. Vlastou C, Earle AS, Blanchard JM: A bed avulsions. Hand Clin 1990;6:39-58. 9. Kappel DA, Burech JG: The cross-finger palmar cross-finger flap for coverage of 27. Kleinert HE, Putcha SM, Ashbell TS, et flap: An established reconstructive pro- thumb defects. J Hand Surg [Am] al: The deformed finger nail, a frequent cedure. Hand Clin 1985;1:677-683. 1985;10:566-569. result of failure to repair nail bed in- 10. Melone CP Jr, Beasley RW, Carstens JH 19. Russell RC, Van Beek AL, Wavak P, et juries. J Trauma 1967;7:177-190. Jr: The thenar flap: An analysis of its use al: Alternative hand flaps for amputa- 28. Atasoy E: Reversed cross-finger subcu- in 150 cases. J Hand Surg [Am] 1982; tions and digital defects. J Hand Surg taneous flap. J Hand Surg [Am] 1982; 7:291-297. [Am] 1981;6:399-405. 7:481-483.

92 Journal of the American Academy of Orthopaedic Surgeons