class iia ring avulsion in.ju:ries:.,.an absolute...

Class IIA ring avulsion in.ju:ries:.,.An absoluteindication for microvascular repair.

The class II ring avulsion category,I includes those patients in whom only digital arteries aredamaged but all other structures are intact and functiona]l (here labeled class IIA). Currentliterature suggests this is a rare lesion. Seven patients with this specific injury in whom theaffected digits were nonviable are repor~ted. Four of the seven were misdiagnosed on initialemergency room evaluation. Two did not seek additional raedical attention and the conditionprogressed to necrosis and amputation. The other two, who sought additional treatment becauseof progressive ischemia, and three additional patients who were correctly diagnosed on initialexamination underwent simple digital arterial repair. All digits operated on survived and dem-onstrated near normal function. Since failure to operate results in digital loss, this is an absolute

indication for microvascular repair. (J HAND SURG 9A:810-15, 1984.)

Mark Nissenbaum, M.D., Philadelphia and Abington, Pa.

P~i’ng avulsion injuries range in severity

from simple abrasions to complete degloving or ampu-tation. Urbaniak et al. 1 reviewed the literature and pro-posed a simplified classification in order to emphasizeprinciples of treatment. Classification and treatmentrecommendations are: class I, circulation adequate--standard bone and soft tissue treatment sufficient; classII, circulation inadequate--vessel repair preservesviability, permitting immediate or delayed repair ofother tissues-~; and class III, complete degloving or

amputation--judgment required since revasculariza-tion of a nonfunctional digit wilI result in a "parasiticmember’’3 (Fig. 1).

The class II category, however, includes a very im-portant subgroup of patients in whom digital artery in-tegrity is compromised but bone, tendons, nerves, andveins are intact. We have arbitrarily labeled them class

IIA. Passing reference to this situation is made in thearticle of Urbaniak et al., 1 and only two other refer-

ences in the literature describe this situation, a’ ~ whichsuggests it is a rare occurrence. This article presents

seven patients with this specific injury, points out thefrequency of misdiagnosis, establishes the anatomicbasis of the mechanism of injury, and emphasizes the

From Jefferson Hospital, Philadelphia, and Abington Hospital,Abington, Pa.

Received for publication Sept. 8, 1983; accepted in revised form Feb.15, 1984.

Reprint requests: Mark Nissenbaum, M.D., 1219 Old York Rd.,Abington, PA 19001.

Fig. 1. Class III ring finger avulsion injury with completedegloving-amputation. Replantation is rarely indicated.

Table 1[. Comparative distribution of ring avulsioninjuries

Injury class [Nissenbaum I Urbaniak et al.~

series series

Class ! (circulation adequate) 3

Class IIA (arterial compro- 7raise only)

(;lass HB (inadequate circula- 7tion with bone, tendon, ornerve injury)

Class [II (complete degloving 5or ~mputation)

2

9

13

810 THE JOURNAL OF HAND SURGERY

Vol. 9ANovemb

Vol. 9A, No. 6November 1984

Class I1A ring avulsion injuries 811

Fig. 2. A-B, Case 1. A 38-year-old farmer who jumped from a haywagon caught his ring finger on aprotruding screw There was dorsal abrasion, and palmar laceration was repaired in a local emer-gency room. Range of motion (ROM) and sensibility were normal at initial evaluation but the fingerwas noted to be "cooler." Patient was discharged with vascular compromise unrecognized.

Fig. 2C. Case 1. Progressive sensory loss prompted reexamination 6 hours later; vascular deficit

was then obvious.

812 Nissenbaum HAND SURGERY

Table II. Clinical material, class IIA ring finger avulsion injuries

Age

(yr) SexMechanism of injury

to ring fingerPatient

Accuracy of

initial diagnosis

Delay from injuryto revascularization

R.R. 38 M Caught on hay wagon Incorrect 8.5 hr

R.L. 32 M Caught in door Correct 2.5 hr

M.A. 41 F Caughl2in leash Correct 3.0 hr

M.N. 37 M Caught in machinery Incorrect Not vascularized

E.N. 29 F Caught around reins Incorrect 5.0 hr

A.R. 40 ." F Caught in leash Correct 2.0 hr

R.G. 32 M Caught in printing press Incorrect Not revascutarized

TAM = total active motion; M = male; F = female; R = radial digital artery; U = ulnar digital artery; P = patent; O = nonpatent; MP = metaearpophalangeal;PIP = "~0xirnal interphalangeal.

Novemb~

Digital a

RURURURURURURU

Fig, 2D. Case 1. View during surgery shows intact digitalnerves and tendon sheath, avulsed radial digital artery (inforceps), and thrombosed ulner digital artery at the level ofthe proximal transverse digital artery.

fact that is is a situation in which simple microvascularrepair means the difference between complete digitalloss and normal or near normal function.

Methods and material

Between July 1977 and July 1983, seven patients

were seen with ring avulsion injuries, minimal skin

laceration, and compromised arterial circulation, butwith all other anatomic su-uctures intact and functional(class IIA; Tables I and II). During the same period,three patients were seen with class I (intact circulation)and five wi~.h class I11 (degloving or amputation). Sevenpatients fell into the class II group (circulation inade-quate) but had other injuries such as fractures or nerve,tendon, and/or venous involvement in addition to arte-rial compromise. These are labeled class IIB injuries

and are excluded from this study (Fig. 2).It is likely that patients with minimal injuries (class I)

are not referred and those with complete degloving oramputation (class III) are treated with primary closureat outlying iinstitutions. As a result, the distribution of

patients reflected in this series probably does not repre-sent the true distribution of the occurrence of theseinjuries. Even so, the class IIA lesion would appear tobe relatively common.

All patients were initially seen by emergency roomor referring physicians prior to my evaluation. Mecha-nism of inju~ry included the following: Four patientscaught a ring on protvading objects, one had a ringcaught by reins, and two had a ring caught by leashes.

Of the.se seven patiehts, four were misdiagnosed oninitial evaluation. The severity of the injury is easilyoverlooked because a finger can maintain normal ROMand near normal sensation for up to 2 or 3 hours after aninjury in which only digital arteries are damaged. Mildvenous stasis can simulate capillary filling. Three of the

four exarainers who did not correctly diagnose the se-verity of arte~dal compromise did, however, note de-

creased temperature of the digit when compared toadjacent finge, rs. This is a consistent early finding.

Diagnosis isdigital Allet

Results

Of the fouevaluation a~symptoms ot

cit, which retion at or nepatients whothe. two patie~

8.5 hours of itoms of numhad surgicalfindings were

The two p~


Digital artery pathology

pathology


Type of repair Operative time

R DividedU ThrombosedR DividedU DividedR DividedU SpasmR DividedU DividedR DividedU DividedR ThrombosedU DividedR DividedU Divided

TAM

End to end 1 hr 45 min 260°

GraftNot repaired I hr 50 min 225~GraftEnd to end 1 hr 55 rain 225°

Advcnticiectomy

Not revascularized

End to end 2 hr 10 rain 250°End to endNot repaired 1 hr 35 rain 220°End to end

Not revascularized

Lon~.,termpatency Comment

R-P Mild cold intoleranceU-OR-O Slight loss of sensationU-PR-P Secondary Z-plastyU-P

R-OU-PR-OU-P

Necrosed; amputation,MP joint

Slight loss of U sensi-bility

30° Flexion/contrac-tion, PIP joint

Necrosed; amputation,MP joint

Fig. 2, E-F. Photographs 8 months after surgery, with full flexion and extension and normalfunctional use.

Diagnosis is confirmed by Doppler evaluation or by adigital Allens test)~

Results

Of the four patients wI~o were misdiagnosed at initial

evaluation and discharged, two did not heed subsequentsymptoms of progressive neurologic and vascular defi-cit, which resulted in necrosis of the digit and amputa-tion at or near the MP joint level (Fig. 3). The threepatients who were correctly diagnosed initially andthe. two patients who sought further medical care within

8.5 hours of initial injury because of progressive symp-toms of numbness, coldness, pain, and color changehad surgical exploration. Essentially similar surgicalfindings were noted in all.

The two patients whose condition had progressed to

complete digital necrosis prior to reevaluation had am-putations performed. Both showed digital arteries di-vided at the level of the proximal transverse digitalarteries.

In the five digits revascularized, all ten digital ar-

teries were nonpatent: Seven vessels were completelydivided, two were thrombosed, and one was in spasmthat ’was :relieved by local adventiciectomy. All pathol-ogy was located at or just distal to the origin of theproximal transverse digital artery.

Seven digital arteries were repaired. Five requiredonly resection of damaged vessel and direct end-to-endrepair. Early in the study, two vessels were treated with

inteiposition reversed vein grafting.With further experience, microbipolar coagulation of

the l:ethering branches of the digital artery allowed ex-

814 Nissenbaum

Fig. 3. Case 4. A 32-year-old man with mechanism of injuryand initial pathology similar to that in case 1, with palmarskin-laceration repaired in an emergency room after which thepatient was discharged. Full ROM and normal sensibilitywere recorded by initial examiner 1 hour after injury. Patientdid not seek additional medical attention until irreversiblenecrosis was established.

tensive tension-free mobilization, and large apparentgaps in the digital arteries could be overcome withoutthe need for reversed vein graft or severe joint flexion.Direct end-to-end repair was performed in the last threepatients (five arteries).

Anticoagulation consisted of aspirin before and aftersurgery and low-molecular-weight dextran during and 2days after surgery. All patients remained on oral aspi-rin, 300 mg/day, for 3 weeks after surgery.

Immobilization after surgery consisted of a dorsalsplint that maintained the digit in enough flexion toeliminate tension on the arterial repairs, never morethan 30° at the MP and PIP joints. Early flexion in thesplint was allowed and immobilization was discon-tinued after 2 weeks.

On follow-up, all revascularized digits survived.Ave}’age TAM was 240°. Digits that showed some digi-tal nerve contusion had slightly altered sensibility butnone showed greater than 6 mm of two-point discrimi-nation. Minimal symptoms of cold intolerance that de-creased with time and local scar problems (one requiredsecondary Z-plasty) were the only residual effects. Allpatients were performing all activities they were beforeinjury without limitations.

Evaluation of patency rates showed that at least onerepaired digital vessel remained patent in each digit. Ofthe nine vessels repaired, six remained patent to digitalAliens test and directional Doppler evaluation.

The Journa~ : fHAND SURGEI,:y

OIG. A.

A5

-C3

DIG. A. -- C2

A3

PROXDIG. A.

- A2

BR. TO VLS

Fig. 4. Tendon sheath and digital vessels demonstrate proxi-mal transverse digital artery. Clinically, these branches areoften less oblique and shorter than illustrated here. Dist.Trans. Dig. A., distal transverse digital artery; Inter. trans.Dig. A., intermediate transverse digital artery; Prox. Trans.Dig. A., proximal transverse digital artery; Br. to VLS,branch to long vinculum; Com. Dig. A., common digitalarte13~. (Reproduced, with permission, from Schneider LH.Hunter JM: Flexor Tendons--Late reconstruction. In GreetDP, editors: Operative hand surgery. New York, 1982,Churchill Livingstone, pp 1375-1440.

Discussi,an

Edwards5 first described the proximal, intermediate,and distal transverse arterial branches that consistentlyarise from each digital artery. The proximal transversedigital artery enters the flexor tendon sheath just distalto the A-2 pulley. It arises at almost a right angle,tethering the digital artery just at the level of maximaiforce exerted by the ring finger. This prevents distalmigration of the vessels with other soft tissues. Dorsalbranches of the digital nerve at this level arise obliquely

Vol. 9A,Novembe

and corngreater e

The e:ring dep~the patiethe mectat greateminimal

This 1rare oneexaminaevaluati~arterial ~intact, nvascular

It is dsurvivedshowedgressivesensibilicapillar3

In di~juries w


and course primarily towards the skin, allowing muchgreater excursion-of the nerve (Fig. 4).

The extent of damage from longitudinal traction on aring depends on the tightness of the ring, the weight ofthe patient, the period, of time the force is applied, andthe mechanism of injury. The tethered digital artery isat greater risk and can be divided or thrombosed withminimal or no injury to other structures.

This lesion is not, as current literature suggests, arare one. Awareness of the entity and careful initialexamination by the digital Aliens test or by Dopplerevaluation should lead to early exploration and simplearterial repair. Since all other anatomic structures areintact, near normal function can be expected after re-vascularization.

It is doubtful whether any of these digits would havesurvived had not arterial repair been performed. Allshowed some degree of dorsal contusion and had pro-gressive ischemic changes characterized by decreasingsensibility and temperature, increasing pain, and loss ofcapillary refill.

In digital amputation or class III ring avulsion in5

juries with compromised function of the joints, ten-


dons, and nerves, injudicious replantation may result ina parasitic member that "only the patient could love."Revascularization ~f class IIA ring avulsion injury,however, :results in as close to a normal digit as possi-ble. Since failure to operate usually results in digitalloss, this situation creates a strong indication for mi-crovascuhtr repair.

REFERENCES

1. Urbaniak JR, Evans JP, Bright DS: Microvascular man-agement of ring avulsion injuries. J H,~No SuR~ 6:25-30,1981

2. Flagg S V, Finseth FJ, Kinzek TJ: Ring avulsion injury.Plast Reconstr Surg 59:241-6, 1977

3. Comtet JJ, Willens P, Moura~ P: Ring injury with bilateralrupture of the digital arteries without skin damage. JH~r~ Su~ 4:415-6, 1979

4. Evans D: Letter to the editor. J HAND SURG 5:294, 19805. Edwards EA: Organization of the small arteries of the ,

hand and digits. Am J Surg 99:837, 19606. Lister G: The hand: Diagnosis and indications. London,

19’77, Churchill Livingstone, p 907. Littler JW: On making a thumb: one hundred years of

surgical[ effort. J HAlo St~ 1:35-51, 1976

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