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Microvascular management of ring avulsion injuries

Microsurgical revascularization has proved to be a useful method in managing the ring avulsion injurywhere both neurovascular bundles are damaged with only partial skin avulsion. Representative corses areused to illustrate guidelines for a practical classification for helping ro decide the optimal ntethod oftreatment of acute ring avulsion injuries in light of digital revascularization techniques. Nine ring fingerswere successfully revascularized of 24 acute ring avulsion injuries reviewed. Sensibil#.v recoveo’ wasgood and a functional range of motion obtained. No patient who has had his ring finger revascularizedhas requested its amputation because of appearance, painful neuromas, stiffness, or cold intolerance.Complete amputations, especially proximal to the superficialis &sertion, and complete degloving injuriesof the ring finger are usually best managed by surgical amputation ~f the digit.

James R. Urbaniak, M.D., John P. Evans, M.D., and Donald S. Bright, M.D.,

Durham, N.C.

Although Gillies a recommended a tubed pedicle for

treatment of "a denuded finger" in 1940, avulsion in-juries due to a ring were first specifically mentioned inthe English orthopedic literature by Bunnell~ in 1948.Other authors discussed primary amputation,a’ ~ pri-mary ray resection, 4’ 5 or complicated resurfacingprocedures,a’ 4’ a-" Some comment has been given con-cerning the microvascular treatment of a single ampu-tated digit, ~, ~0 but no one has published a useful guideto treatment incorporating revascularization concepts.All of these options have complications. The primaryamputation involves complete loss of the finger, loss ofsymbolic position of the ring finger, possible painfulneuromas, or loss of good pulp tissue. Primary rayresection is expedient, but involves the above-men-tioned complications plus loss of palmar width. Long,Complicated skin and neurovascular pedicle operationsinvolve periods of immobilization with frequent occur-rences "of joint stiffness, infection, bulbous fingertips,

and loss of sensibility. These potential complicationscan be avoided with successful microvascular recon-stitution of a severely damaged ring finger.

Treatment guide

To be effective, a classification should be short, easyto remember, and practical, With microvascular tech-niques in mind, ring avulsion treatment can be sepa-

rated into three classes.

From the Division of Orthopaedic Surgery, Duke University Medical

Center, Durham, N.C.

Received for publication Dec. 21, 1979; revi~ed April 21, 1980.

Reprint requests: James R. Urbaniak, M.D., Box 2912--Ortho-paedic Surgery, Duke University Medical Center, Durham, NC27710

Class I: Circulation adequate. Standard bone andsoft tissue treatment is sufficient.

Class II: Circulation inadequate. Vessel repairpreserves viability permitting immediate or delayed re-pair of other tissues.

Class III: Complete degloving or complete ampu-tation. Judgment is essential because, although acomplete amputation can be revascularized and viabil,ity restored, the potential function is limited. In deglov-

ing injuries, the potential for useful function exists, butrevascularization is not easy or may not be possible.

Representative eases

’Class I: Circulation adequate. W. W., a 33-year-oldright-handed construction worker, caught the ring on his leftring finger on a falling cinder block, causing an almost cir-cumferential laceration of the skin at the distal end of theproximal phalanx (Fig. 1). Damage involved the ex~-nsormndon, flexor digitorum superficialis and profundus, andopen dislocation of the middle joint with tearing of the volarplate from its insertion. The intact ulnar digital artery andnerve maintained good circulation ~nd turgot to the distal endof the finger. Standard wound care was used involving exten-sor and flexor tendon repair, a volar plate reattachment, irri-gation, and dressing of the wound with subsequent delayedsk!n closure. The patient achieved an essentially full painlessrange of motion (0° to 110° at the proximal interphalangea!joint), normal sensibility, and cold tolerance in the digit.

Class II: Circulation inadequate. J. B., a 24-year-oldright-handed construction worker, fell 8 feet and caught hiswedding ring on the scaffold, sustaining a complete circum-ferential degloving type injury extending to the base of thefingernail (Fig. 2). All tendons and bones were intact. Thedistal joint was dislocated, with rapture of the volar plate andcollateral ligaments..Both neurovascular bundles and all dor-sal v~ins were avulsed with the skin. There was inadequatepeffusion of the distal digit as evidenced by no capillary refill,

0363-5023181/010025+06500.60/0 © t981 American Society for Surge~:y of the Hand THE JOURNAL OF HAND SURGERY 25

26 Urbaniak, Evans, and Bright

Fig, 1, Class I type of ring injury in a 33-year-old construc-tion worker. The skin injuU was circumferential with lacera-tion of the extensor tendon, flexor superficialis, and profun-dus and open dislocation of the proximal interphalangeal jointwith injury to the volar plate. One intact neurovascular bundlemaintained good circulation. Standard wound care, tendon,nerve, and volar plate repair, and delayed skin closure re-sulted in a good range of motion and sensibility return,

poor pulp turgor, coldness, and pallor (Fig. 2, B). Immediatecare included irrigation and debridement of the wound withmicrosurgical repair of both digital nerves, three dorsal veins,and one volar vein. A 2 cm vein graft to the radial digitalartery and a 1.5 cm vein graft to the ulnar digital artery wereperformed. The digit survived and had a total active range ofmotion of 225°. Two-point discrimination was 9 mm and thepatient recovered power grip strong enough to use a hammeron the job. His cold intolerance subsided after 1 year.

Class III: Complete amputation or complete degloving.D. B., a 23-year-old Lumbee Indian male mechanic, sus-tained an amputation of the left ring finger after catching hisring on a truck (Fig. 3). The fracture involved the proximalinterphalangeal joint and the skin was avulsed from the baseof the proximal phalangeal level. Successful replantation ofthe amputated finger involved proximal interphalangeal jointfusion and repair of the extensor tendon, both digital arteries,and nerves and five dorsal veins. He has recovered 12 mm oftwo-point discrimination and a full active range of motion ofthe metacarpophalangeal joint, but has rigid proximal anddistal interphalangeal joints. He has never been quite satisfied

The Journal ofHAND SURGERY

with the appearance and function of the digit and was out ofwork for n~rly 18 months.

Material

Between 1974 and 1979, 24 patients with an isolatedring avulsion type injury to the ring finger were seen inthe’, Duke University Medical Center Orthopaedic Sur-gery Division (Table I). Seven patients who had thedil;it separated completely from the hand had an at-tempt at full replantafion. Of these seven, five digitssurvived and two underwent delayed amputation. Allthree children in the series had complete amputationsan~d all underwent replantation. Two of these replanteddigits survived. Six patients were treated by amputationwithout an attempt at revascularization or replantation.

Sixteen ring fingers underwent revascularization orreplantation and 14 survived. None of these patientshas requested amputation of the revascularized digit.Although the finger may be shorter, all but one patientwas pleased with the appearance.

Primary nerve repair was performed when feasible;however, if the injury was of the severely avulsingtype, secondary repair or delayed nerve grafting wasperformed. None of the patients in the revascularizedseries has required reoperation for resection of a painfuldigital neuroma--a frustrating complication of ampu-tations and ray resections. TM ~-~

Of nine successfully revascularized fingers availablefc~r follow-up, two-point discrimination averaged 10ram (this includes only digits which had nerves severedztnd repaired) and total active motion 206°. Threecompletely replanted digits averaged 12 mm of two-point discrimination and total active motion of only145°. Most of the restricted joint motion occurred at theproximal interphalangeal joint.

At the present time, our replantation team can replanta single digit in 3 hours or less of operating time. Sincering avulsion injuries frequently damage along sectionof the vessels, vein grafting is frequently necessary andthe procedure may be prolonged an hour or so. Thehospital stay of a single replanted digit is usually 5 to 8days. In our institution the cost of revascularizing a ringavulsion is comparable to the amount of financial com-pensation the patient (who has been injured on the job)would receive from the insurance carrier if the digitwere amputated and not revascularized.

The patients in this study who had revascularizationor replantation of digits have averaged 3 months out ofwork. The patients with complete amputations whichwere not replanted averaged more than 2 months out ofwork. Four patients required on additional operationeach. One patient who had a complete amputation and

al of Vol. 6, No. 1=_,RY~ January 1981 Ring avulsion injuries 27

Fig. 2. Class II type of ring injury in a 24-year-old construction worker. The tendons and bone wereintact. The distal joint was dislocated and all neurowtscular structures were severely severed (A).The digit appeared avascular with no capillary re:fill (R). Because of the degloving type of vasculardamage (C), vein grafts were necessary to both digital arteries. Four veins and both nerves wererepaired. Two-point discrimination of 9 mm and. total active motion of 225° was achieved.

replantation has required four additional procedures.He would have benefited more from a primary ampu-tation.

Discussion

Discrimination is necessary in the management ofring finger avulsion injuries. Significant digital vasculardamage may occur in a ring injury even though the skinremains intact. 13 The physician should be aware of thispossibility and evaluate the blood flow of the injureddigit by capillary refill, digital Allen test, and Dopplermonitoring, or pulse volume recorder, if available.

If the skin has been opened by tti’e ring avulsion

injury, the vascular status of the. digit must be deter-mined. If the circulation, both arterial and venous, isadequate (Class I), basic wound care only is necessary.I:a the circumferential injury the skin should not beclose.d, but left open to prevent constriction and venousstasis which is likely from the posttraumatic edemawhich always occurs in this injury. During the first 4 or5 days after the injury, frequent examination of thevascular status of the digit is mandatory.

The avulsing ring injury without .complete amputa-tion or degloving (Class II) usually damages the digital~trteries, or veins, or both. The circulatory status of theinjured digit can usually be determined by clinical ob-

28 Urbaniak, Evans, and BrightThe Journal of

HAND SURGERY

Fig. 3. Class III type of injury with a complete amputation of the ring finger at the proximalinterphalangeal joint level (A). The digit was successfully replanted (B), but the patient was out work for 18 months and had a limited range of motion.

Table I. Ring finger avulsions

Amputation type Class Treatment

Incomplete (11) I (2) Debride onlyII (9) Revascularized

Complete (13) III (7) ReplantedIII (6) Amputated

Total 24

Survival

servation of the pulp turgor, color, and capillary refill.Again, monitoring devices help to evaluate the patencyof the digital vessels. The most reliable method of de-termining the status of the digital vessels is to examinethe injured digit under the operating microscope. Fol-lowing axillary or brachial block and manipulation ofthe injured digit in preparation for the microsurgicalexamination, the surgeon may be pleasantly surprisedto observe return of blood flow to a previously avascu-lar digit. This spontaneous vascular recovery, which

occurs not infrequently, indicates vascular spasm orpartial arterial thrombosis which has been relieved byan improvement of the environment (pain relief, relax-ation of the patient, warmer temperature, reduction of afracture or dislocation, or relief of pressure). Carefulmicroscopic examination determines which vessels andnerves can or should be repaired. Vein grafts or shiftingof one reparable digital artery stump to the opposite

side of the digit to attach it to a healthy distal stump are

often needed. An attempt should be made to obtain twopatent arteries and a minimum of three good veins.Because of the mechanism of injury, the nerves areoften injured over a long area. However, with resectionunder the microscope, normal fascicles can usually beidentified and end-to-end repair achieved. We have notperformed primary nerve grafting as some microsurg-ec,ns have recommended, but have preferred to do sec-ondary nerve grafting in the few digits in which directrepair was not feasible. On occasions, the arterialinflow may be adequate, and only the veins need to bereconstructed; conversely, only the arteries may needreconstruction if the dorsal skin is intact.

With the aid of microsurgery, the incomplete ringdegloving or amputation with vascular deficit can nowbe successfully revascularized in almost all instances.The active range of motion, sensibility, strength, andappearance of the digit should approach normal most ofthe time.

The completely amputated or degloved ring finger(Class III) presents a more difficult problem. Achievinga viable digit by replantation is frequently possible,us~aally with the use of vein grafts. However, the ulti-mate success of the replanted ring finger involves muchmore than obtaining a viable digit. Is the grip im-proved? Can useful motion be obtained? Is sensibilitynear normal? Is the appearance acceptable? What is the

Vol. 6, No. 1January 1981 Ring avulsion injuries 29

Fig. 4. Class III injury with complete degloving of the ring finger in the 32-year-old wife of aphysician. The flexor and extensor tendons remained intact and she was able to fully flex and extendthe degloved digit (A, B). Attempt at replantation failed after 5 days because of extensive digitalartery damage throughout the distal digital arteries which were in the degloved part (C).

time lost from work? Can the patient return to his pre-vious job? How many more operations will be neces-sary? What is the duration of the replantation surgeryand the hospitalization? What is the chance of survival?Based on our experience with ring avulsion injuries,most of these questions can be answered preoperatively.

The decision of whether to replant the completelyamputated or avulsed digit is difficult to resolve.Examination of the digital vessels of the degloved skinunder the microscope may reveal that it is impossible toi’eestablish blood flow because of the irreversible dam-age of the distal vessels, and the choice to amputatebecomes obvious. The degloved finger with intact ten-dons may fully flex and extend, but is still doomedwithout revascularization of the skin because of lack ofsatisfactory skin coverage and nutrition. Tubed pediclecoverage, results in poor appearance, inadequate sen-sibility, and possibly joint stiffness.

In the Class III injury, if one or more joints aredamaged and arthrodesis (particularly of the proximalinterphalangeal joint) will result, replantation is lesslikely to be considered. If the patient is a laborer, we

’ usually favor amputation, because if replantation is per-formed, the hospitalization will be about 1 week, thetime lost from work will be 3 or 4 months, and sub-sequent reconstructive surgery is.~kely (tendon or

nerve surgery). In addition, the grip obtained in replant-ing the completely amputated ring finger is about thesame as the grip of a patient with an amputated ringfinger.

Success in achieving viability is most difficult in thecompletely degtoved digit (Fig. 4). In helping to makethe decision, the patient should be informed of thelikelihood of failure and the cost and length of theoperation and hospitalization. In a young woman orchild, we would be more likely to attempt restorationbig revascularization of the degloved part, for if su~Eessoccurs the appearance would be near normal and themotion and sensibility satisfactory. In the adult with acomplete amputation of the ring. finger proximal to thesuperficialis insertion, we recommend not attemptingreptantation.

Conclusion

~icrosurgical revascularization has been particularlyuseful in salvaging incomplete ring avulsion amputa-tions with insufficient vascular flow. Nine ring fingersinjured by a ring avulsion have been successfully re-vascularized, and good sensibility a~nd useful motion ofthe digits have been obtained. Six ring fingers weretreated by amputation, either from the original injury orby the surgeon. Of seven completely amputated or de-

30 Urbaniak, Evans, and Bright

gloved ring fingers that were replanted, five survived,but had limited motion. Considerable judgment is in-volved when deciding whether to replant a completelyamputated or degloved finger, but generally we favorrevision of the amputation.

REFERENCES

1. Gillies HD: Autograft of amputated digit: suggested op-eration. Lancet 1:1000-3, 1940

2. Bunnell S: Surgery of the hand. Philadelphia, 194.8, J BLippincott

3. Beuin AG, Chase RA: The management of ring avulsioninjuries and associated conditions in the hand. Plast Re-constr Surg 32:391-9, 1963

4. Thompson LK, Posch JL: Ring injuries. Plast ReconstrSurg 42:148-51, 1968

5. Carroll RE: Ring injuries in the hand. Clin Orthop104:175-82, 1974

6:.-.Alonso-Artieda M: Reimplantation of an avulsed ringfinger using a sensory cross-finger flap. Br J Plast Surg23:293-95, 1971

The Journal ofHAND SURGERY

7. Crawford J, Horton C: Avulsion of ring finger skin. PlastRecon~tr Surg 10:46-9, 1952

8. Flagg SV: ~Ring avulsion injury. Plast Reconstr Surg59:241-8, 1977Holevich J: Early skin-grafting in the treatment of trau-matic avulsion injuries of the hand and fingers. J BoneJoint Surg [Am] 47:944-56, 1965

10. Yoshitzu T et al: Replantation of untidily amputatedfingers, hands and arms: experience of 99 replantationsin 66 cases. J Trauma 18:194-200, 1978

11. Tupper JW, Booth DM: Treatment of painful neuromasof sensory nerves in the hand: a comparison of traditionaland newer methods. J HAND SURG 1:144-51, 1976

12. Murray JF, Carman W, MacKenzie JK: Transmetacarpalanaputation of the index finger: a clinical assessment ofhand strength and complications. J HaND SUR6 2:471-81, 1977

13. Comtet JJ, Willens P, Mouret P: Ring injury With bilat-eral rapture of the digital arteries without skin damage. JHAND SURG 4:415-17, 1979 ~

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