Approach to Fingertip Injuries

Open AccessPublished:April 16, 2019DOI:https://doi.org/10.1016/j.cps.2019.02.001

      Keywords

      Key points

      • Fingertip injuries are common and there is a wide spectrum of presentation.
      • Restoration of a stable, pain-free, and normal looking fingertip is the main goal of treatment.
      • Psychosocial factors are important considerations in the formulation of a treatment plan.

      Introduction

      The fingertip comprises the nail complex and glabrous pulp, which are richly vascularized and innervated, built around the distal phalanx. Its dense innervation
      • Mancini F.
      • Chiara F.
      • Ramirez J.D.
      • et al.
      A fovea for pain at the fingertips.
      and disproportionally large and intricate cortical representation
      • Roux F.E.
      • Djidjeli I.
      Functional architecture of the somatosensory homunculus detected by electrostimulation.
      emphasize the importance of addressing psychological factors. Minor contusions can result in pain syndromes in some patients, whereas others adapt well to deformed fingertips, highlighting the nonlinear relationship between physical and psychological trauma.

      Goals of treatment

      The goals of treatment of any injured fingertip should be the restoration of a stable interface for object manipulation while looking as normal as possible. At the completion of treatment, the pulp should be stable and pain free, and the nail plate geometry should permit the manipulation of small objects.

      Planning treatment

      A focused history and physical examination is obtained to establish the most appropriate intervention for each patient. The characteristics of the injury determine the range of treatment, whereas psychosocial factors aid clinicians in selecting the most appropriate option. Psychosocial factors to be considered are occupation, hobbies, cultural norms, socioeconomic status, secondary motive, and clinician bias.
      • Hustedt J.W.
      • Chung A.
      • Bohl D.D.
      • et al.
      Evaluating the effect of comorbidities on the success, risk, and cost of digital replantation.
      • Payatakes A.H.
      • Nikolaos P.
      • Fedorcik G.G.
      • et al.
      Current practice of microsurgery by members of the American society for surgery of the hand.
      • Shi Q.
      • Sinden K.
      • M J.C.
      • et al.
      A systematic review of prognostic factors for return to work following work-related traumatic injury..
      • Peacock S.
      • Patel S.
      Cultural influences on pain.
      • Steinberg F.
      The law of workers’ compensation as it applies to hand injuries.
      • Lee P.W.
      • Ho E.S.
      • Tsang A.K.
      • et al.
      Psychosocial adjustment of victims of occupational hand injuries.

      Closed injuries

      The 3 main considerations for closed fingertip injuries are the nail plate, pulp, and bone. The size of the subungual hematoma is thought to correlate with the degree of the nail matrix injury, and an arbitrary figure of 50% is considered an indication for nail avulsion and matrix repair (Fig. 1) to facilitate anatomic healing.
      • Simon R.R.
      • Wolgin M.
      Subungual hematoma: association with occult laceration requiring repair.
      An alternative approach, where nail trephination alone was performed regardless of the size of the hematoma, provided the nail plate was intact, yielded good pain relief with satisfactory nail plate regeneration.
      • Seaberg D.C.
      • Angelos W.J.
      • Paris P.M.
      Treatment of subungual hematomas with nail trephination: a prospective study.
      The presence of a tuft fracture did not adversely affect the outcome in this series, in which patients with fractures received a splint to maintain the distal interphalangeal joint in extension for comfort.
      Figure thumbnail gr1
      Fig. 1A 75% hematoma with intact nail plate (left). Untidy laceration with interposed hematoma (middle). Laceration is evident after clearance of hematoma (right). Nail trephination is a viable alternative in this scenario.

      Open injuries without tissue loss

      Given the density of critical structures in the fingertip, it is prudent to exclude flexor tendon, digital nerve, or artery laceration in open injuries of the pulp (Fig. 2). Although distal digital nerve repair does not predict sensory recovery,
      • Yamano Y.
      Replantation of the amputated distal part of the fingers.
      • Dubert T.
      • Houimli S.
      • Valenti P.
      • et al.
      Very distal finger amputations: replantation or “reposition-flap” repair?.
      it is worth documenting and repairing neurotmetic injuries in clinical practice for which medicolegal risks are high. Nail matrix injuries are typically repaired with absorbable sutures to restore contour and surface for nail regeneration. Skin glue is an effective alternative to sutures for the repair of simple or complex lacerations and suitable for children in the emergency room setting.
      • Yam A.
      • Tan S.H.
      • Tan A.B.
      A novel method of rapid nail bed repair using 2-octyl cyanoacrylate (Dermabond).
      Figure thumbnail gr2
      Fig. 2Simple laceration of the thumb pulp resulted in transection of the digital nerve, which was repaired (left). Flexor tendon and digital nerves were found to be intact in a burst laceration of the pulp (right).

      Open injuries with tissue loss

       Healing by Secondary Intention

      Pulp reconstruction after tissue loss receives disproportionate attention owing to the wide array of options for reconstruction, limited only by imagination. Before indulging our imagination, it is worth considering the possibility of healing through secondary intention, which can be surprisingly effective; its results may be aesthetically superior to graft or flap reconstruction, without incurring donor site morbidity.
      • Lee L.P.
      A simple and efficient treatment for fingertip injuries.
      Common indications for secondary intention healing are wounds without exposed bare bone or tendon, and a wound size of less than 1 cm2. However, noncritical portion of exposed bone or tendon can be excised to facilitate healing. Wound vascularity rather than size is more important in considering treatment options; a small, well-vascularized wound (<1 cm2) would almost certainly recover in a week or two, whereas larger wounds would take a few weeks more. Graft or flap reconstruction expedites the recovery process, while incurring potential donor morbidity. The principles of secondary intention can be applied to reduce flap requirement, for example, using a smaller flap to cover only the critical portion, whereas residual defects are allowed to heal by secondary intention (Fig. 3).
      Figure thumbnail gr3
      Fig. 3Fingertip amputation treated with a modified local advancement flap (left). Residual defects (A, B) were allowed to heal by secondary intention (2 weeks, middle) with a satisfactory outcome (3 months, right).

       Composite Graft

      The outcome of a composite graft is generally predictable in young children,
      • Butler D.P.
      • Murugesan L.
      • Ruston J.
      • et al.
      The outcomes of digital tip amputation replacement as a composite graft in a paediatric population.
      but outcomes were less predictable in adults.
      • Chen S.Y.
      • Wang C.H.
      • Fu J.P.
      • et al.
      Composite grafting for traumatic fingertip amputation in adults: technique reinforcement and experience in 31 digits.
      In adults, we observed some degree of graft shrinkage and contour distortion with nail deformity (Fig. 4). As long as the patient understands the implications of the procedure, composite grafting is a good alternative with no donor morbidity.
      Figure thumbnail gr4
      Fig. 4Avulsion amputation of the pulp was replaced as a composite graft in an adult patient. Graft atrophy and fingertip contour and nail plate distortion observed 6 months later

       Skin Grafts

      Moynihan
      • Moynihan F.J.
      Long-term results of split-skin grafting in finger-tip injuries.
      reported that the “condemnation of the use of Thiersch graft (split skin graft) has almost been unanimous,” and this paradigm has been preserved and inherited by contemporary surgeons. It is worth noting that Moynihan stressed that a thin graft over a bony prominence was the cause of tenderness and sensitivity rather than the use of split thickness graft.
      • Shepard G.H.
      Treatment of nail bed avulsions with split-thickness nail bed grafts.
      • Yong F.C.
      • Teoh L.C.
      Nail bed reconstruction with split-thickness nail bed grafts.
      A full-thickness skin graft (FTSG) was applied with caution over exposed bone and tendon in the mid twentieth century, but contemporary investigators have shown that a FTSG can be reliably used in the context of exposed bone or tendon.
      • Lee J.H.
      • Burn J.S.
      • Kang S.Y.
      • et al.
      Full-thickness skin grafting with de-epithelization of the wound margin for finger defects with bone or tendon exposure.
      We use skin grafts judiciously for pulp reconstruction, and we note imperceptible differences between glabrous and nonglabrous graft in the long term, because the graft remodels according to stress to which it is exposed (Fig. 5). Donor site morbidity is prioritized over like-for-like reconstruction because there are limited donor sites for glabrous skin. The ulnar aspect of the hand has been described as a donor site, but we would avoid this area because it is often the surface on which the hand rests during activity. The palmar creases, midaxial skin, and dorsal joint creases provide FTSG that are up to 15 mm wide with minimal functional and cosmetic morbidity (Fig. 6).
      • Tan R.E.
      • Ying C.T.Q.
      • Sean L.W.H.
      • et al.
      Well-camouflaged skin graft donor sites in the hand.
      • Germann G.
      • Rudolf K.D.
      • Levin S.L.
      • et al.
      Fingertip and thumb tip wounds: changing algorithms for sensation, aesthetics, and function.
      Figure thumbnail gr5
      Fig. 5Skin grafts remodel according to the stress imposed upon it. Glabrous remodeling of skin grafts noted in the long term at 3 years after split thickness skin graft (left), and 25 years after FTSG (right).
      Figure thumbnail gr6
      Fig. 6FTSGs can be harvested from inconspicuous sites such as palmar crease (left), mid axial skin (middle), and dorsal digital crease (right) to optimize the appearance of the hand or digit.

       Flap Reconstruction

      Few topics excite hand surgeons as much as a discussion of the options for fingertip reconstruction. The majority of fingertip losses are adequately treated with VY advancement
      • Atasoy E.
      • Ioakimidis E.
      • Kasdan M.L.
      • et al.
      Reconstruction of the amputated fingertip with a triangular volar flap. A new surgical procedure.
      • Tranquilli-Leali E.
      Ricostruzione dell’apice delle falangi ungueali mediante autoplastica volare peduncolata per scorrimento.
      and cross-finger flaps.
      • Gurdin M.
      • Pangman W.J.
      The repair of surface defects of fingers by trans-digital flaps.
      Island flaps extend the options for further refinement of reconstructive approach, while imposing greater technical demands. Surgical techniques on numerous flaps can be found in the works by these investigators.
      • Foucher G.
      • Khouri R.K.
      Digital reconstruction with island flaps.
      • Rehim S.A.
      • Chung K.C.
      Local flaps of the hand.
      These texts are by no means exhaustive, because new or modifications of known techniques are frequently reported in the literature.
      Our flap selection process is based on the dichotomy of homodigital versus heterodigital options, followed by patient choice, and then surgeon expertise. Patients are shown a photo of the anticipated outcome of the common flaps because their perception of the beautiful normal may vary. From a surgical perspective, we encourage younger colleagues to master VY advancement and cross-finger flaps before undertaking the various forms of neurovascular or vascular island flaps. We generally avoid heterodigital flaps to limit injury to a single digit, and similarly, cross-finger flaps are avoided in older patients owing to the higher risk of finger stiffness. VY flaps,
      • Atasoy E.
      • Ioakimidis E.
      • Kasdan M.L.
      • et al.
      Reconstruction of the amputated fingertip with a triangular volar flap. A new surgical procedure.
      • Tranquilli-Leali E.
      Ricostruzione dell’apice delle falangi ungueali mediante autoplastica volare peduncolata per scorrimento.
      triangular,
      • Venkataswami R.
      • Subramanian N.
      Oblique triangular flap: a new method of repair for oblique amputations of the fingertip and thumb.
      or step-cut
      • Evans D.M.
      • Martin D.L.
      Step-advancement island flap for fingertip reconstruction.
      neurovascular island flaps are our workhorses for fingertip reconstruction. Frequent contact areas such as radial aspect of index and middle fingers, and ulnar aspect of little finger are avoided as island flap donor sites to minimize scar sensitivity (Fig. 7). Dissection and mobilization of the neurovascular bundle up to the common digital artery bifurcation with or without adjacent arterial division is routinely performed to facilitate flap advancement of 15 to 20 mm. Proximal interphalangeal joint flexion is avoided, and postprocedure proximal interphalangeal joint mobilization is emphasized to minimize joint stiffness.
      Figure thumbnail gr7
      Fig. 7Pulp loss of the left index finger was reconstructed with an ulnar-based triangular advancement flap to avoid sensitivity along the radial border of the index finger. Finger mobility exercise decreased joint stiffness.
      Retrograde flow vascular island flaps
      • Lai C.S.
      • Lin S.D.
      • Yang C.C.
      The reverse digital artery flap for fingertip reconstruction.
      • Adani R.
      • Busa R.
      • Pancaldi G.
      • et al.
      Reverse neurovascular homodigital island flap.
      provide great flexibility for pulp reconstruction should collateral flow through palmar arches be well-preserved. The conventional technique requires FTSG to cover donor site along the mid axis of the proximal phalanx, whereas a modified approach we adopted could obviate the requirement to promote better donor site appearance (Fig. 8).
      Figure thumbnail gr8
      Fig. 8Flap (star) and donor site (arrow) appearance with conventional (left) and modified (right) approaches, where the donor site was closed primarily rather than skin grafted to provide better appearance.
      In our practice, we avoid heterodigital flaps to minimize cortical disorientation and donor site morbidity
      • Littler J.W.
      The neurovascular pedicle method of distal transposition for reconstruction of the thumb.
      • Woon C.Y.
      • Lee J.Y.
      • Teoh L.C.
      Resurfacing hemipulp losses of the thumb: the cross finger flap revisited: indications, technical refinements, outcomes, and long-term neurosensory recovery.
      • Teoh L.C.
      • Tay S.C.
      • Yong F.C.
      • et al.
      Heterodigical arterialized flaps for large finger wounds: results and indications.
      for digital (eg, thumb) reconstruction. For thumb pulp reconstruction, we prefer either the locoregional flaps
      • Woon C.Y.
      • Lee J.Y.
      • Teoh L.C.
      Resurfacing hemipulp losses of the thumb: the cross finger flap revisited: indications, technical refinements, outcomes, and long-term neurosensory recovery.
      • Pho R.W.
      Local composite neurovascular island flap for skin cover in pulp loss of the thumb.
      • Foucher G.
      • Braun J.B.
      A new island flap transfer from the dorsum of the index to the thumb.
      • Brunelli F.
      • Vigasio A.
      • Valenti P.
      • et al.
      Arterial anatomy and clinical application of the dorsoulnar flap of the thumb.
      or free toe pulp transfer. In the long term, there is no significant difference between the sensory perception of innervated and noninnervated flaps.
      • Woon C.Y.
      • Lee J.Y.
      • Teoh L.C.
      Resurfacing hemipulp losses of the thumb: the cross finger flap revisited: indications, technical refinements, outcomes, and long-term neurosensory recovery.

      Bone loss

      Bone loss and geometric distortion are concerns in oblique fingertip amputations. To minimize loss of bone support and fingertip length, a vascularized bone graft can be obtained as part of a VY flap
      • Foo T.L.
      • Arul M.
      Osteocutaneous VY flap to preserve length in coronal oblique fingertip amputation.
      to reconstruct the fingertip while preserving length (Fig. 9).
      Figure thumbnail gr9
      Fig. 9Oblique amputation reconstructed with a osteocutaneous VY flap to reconstitute the nail complex contour (bone outline in dashed line). Satisfactory nail contour and normal looking fingertip after remodeling.

       Nail Complex Reconstruction

      In situations where residual nail complex is sparse, nailfold recession
      • Xing S.
      • SHen Z.
      • Jia W.
      • et al.
      Aesthetic and functional results from nailfold recession following fingertip amputations.
      could be considered to augment relative length of the nail plate (Fig. 10). Nail matrix graft from an amputated toe (Fig. 11) or a split thickness graft from the toes may be obtained to reconstruct missing matrix. In the complete loss of nail matrix, FTSG may be performed with satisfactory results. Of note is that the direct application of a graft on a bare distal phalanx cortex (Fig. 12) does not compromise graft nutrition.
      • Puhaindran M.E.
      • Cordeiro P.G.
      • Disa J.J.
      • et al.
      Full-thickness skin graft after nail complex resection for malignant tumors.
      Figure thumbnail gr10
      Fig. 10A very short nail complex can be relatively lengthened by recessing the eponychium. A crescent area of skin is excised (dashed lines) and the eponychium is advanced proximally to expose more matrix.
      Figure thumbnail gr11
      Fig. 11Amputation injury with bone and matrix loss (left). Matrix graft obtained as spare parts from amputate (middle) replaced over VY advancement flap. Acceptable outcome achieved at 3 months (right).
      Figure thumbnail gr12
      Fig. 12Dorsal shaving injury resulting in loss of nail matrix (left), replaced by FTSG (intermediate stage, middle) and eventual satisfactory outcome (3 months, right).

      Summary

      Fingertip injuries affect patients in numerous ways and outcomes are not always predictable. Each encounter calls for a considered evaluation of the functional and aesthetic expectations of patients, tailored to societal and cultural norms. The treatment goal of a pain-free and functional fingertip is weighed against the potential morbidity and expected outcome of the proposed procedure. The healing and remodeling trajectory of bone, pulp tissue, nail matrix, and grafts vary considerably. These variables are to be considered in the formulation of the overall treatment plan for fingertip injuries.

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