Class IIA ring avulsion in.ju:ries:.,.an indication for microvascular repair.

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1 Vol. 9A Novemb Class IIA ring avulsion in.ju:ries:.,.an indication for microvascular repair. absolute The class II ring avulsion category, I includes those patients in whom only digital arteries are damaged but all other structures are intact and functiona]l (here labeled class IIA). Current literature suggests this is a rare lesion. Seven patients with this specific injury in whom the affected digits were nonviable are repor~ted. Four of the seven were misdiagnosed on initial emergency room evaluation. Two did not seek additional raedical attention and the condition progressed to necrosis and amputation. The other two, who sought additional treatment because of progressive ischemia, and three additional patients who were correctly diagnosed on initial examination underwent simple digital arterial repair. All digits operated on survived and demonstrated near normal function. Since failure to operate results in digital loss, this is an absolute indication for microvascular repair. (J HAND SG 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 amputation. rbaniak et al. 1 reviewed the literature and proposed a simplified classification in order to emphasize principles of treatment. Classification and treatment recommendations are: class I, circulation adequate-- standard bone and soft tissue treatment sufficient; class II, circulation inadequate--vessel repair preserves viability, permitting immediate or delayed repair of other tissues-~; and class III, complete degloving or amputation--judgment required since revascularization of a nonfunctional digit wili result in a "parasitic member 3 (Fig. 1). The class II category, however, includes a very important subgroup of patients in whom digital artery integrity is compromised but bone, tendons, nerves, and veins are intact. We have arbitrarily labeled them class IIA. Passing reference to this situation is made in the article of rbaniak et al., 1 and only two other references in the literature describe this situation, a ~ which suggests it is a rare occurrence. This article presents seven patients with this specific injury, points out the frequency of misdiagnosis, establishes the anatomic basis of the mechanism of injury, and emphasizes the From Jefferson Hospital, Philadelphia, and Abington Hospital, Abington, Pa. eceived for publication Sept. 8, 1983; accepted in revised form Feb. 15, eprint requests: Mark Nissenbaum, M.D., 1219 Old York d., Abington, PA Fig. 1. Class III ring finger avulsion injury with complete degloving-amputation. eplantation is rarely indicated. Table 1[. Comparative distribution of ring avulsion injuries Injury class [ Nissenbaum ~ I rbaniak et al. series series Class! (circulation adequate) 3 Class IIA (arterial compro- 7 raise only) (;lass HB (inadequate circula- 7 tion with bone, tendon, or nerve injury) Class [II (complete degloving 5 or ~mputation) THE JONAL OF HAND SGEY

2 Vol. 9A, No. 6 November 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 a protruding screw There was dorsal abrasion, and palmar laceration was repaired in a local emergency room. ange of motion (OM) and sensibility were normal at initial evaluation but the finger was 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.

3 812 Nissenbaum HAND SGEY Novemb~ Table II. Clinical material, class IIA ring finger avulsion injuries Patient Age (yr) Sex Mechanism of injury to ring finger Accuracy of initial diagnosis Delay from injury to revascularization Digital a.. 38 M Caught on hay wagon Incorrect 8.5 hr.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.. 40." F Caught in leash Correct 2.0 hr.g. 32 M Caught in printing press Incorrect Not revascutarized TAM = total active motion; M = male; F = female; = radial digital artery; = ulnar digital artery; P = patent; O = nonpatent; MP = metaearpophalangeal; PIP = "~0xirnal interphalangeal. Fig, 2D. Case 1. View during surgery shows intact digital nerves and tendon sheath, avulsed radial digital artery (in forceps), and thrombosed ulner digital artery at the level of the proximal transverse digital artery. fact that is is a situation in which simple microvascular repair means the difference between complete digital loss 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, but with 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). Seven patients fell into the class II group (circulation inadequate) but had other injuries such as fractures or nerve, tendon, and/or venous involvement in addition to arterial 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 or amputation (class III) are treated with primary closure at outlying iinstitutions. As a result, the distribution of patients reflected in this series probably does not represent the true distribution of the occurrence of these injuries. Even so, the class IIA lesion would appear to be relatively common. All patients were initially seen by emergency room or referring physicians prior to my evaluation. Mechanism of inju~ry included the following: Four patients caught a ring on protvading objects, one had a ring caught by reins, and two had a ring caught by leashes. Of the.se seven patiehts, four were misdiagnosed on initial evaluation. The severity of the injury is easily overlooked because a finger can maintain normal OM and near normal sensation for up to 2 or 3 hours after an injury in which only digital arteries are damaged. Mild venous stasis can simulate capillary filling. Three of the four exarainers who did not correctly diagnose the severity of arte~dal compromise did, however, note decreased temperature of the digit when compared to adjacent finge, rs. This is a consistent early finding. Diagnosis is digital Allet esults Of the fou evaluation a~ symptoms ot cit, which re tion at or ne patients who the. two patie~ 8.5 hours of i toms of num had surgical findings were The two p~

4 Vol. 9A, No. 6 November 1984 Class I1A ring avulsion injuries 813 Digital artery pathology pathology Divided Thrombosed Divided Divided Divided Spasm Divided Divided Divided Divided Thrombosed Divided Divided Divided Type of repair Operative time TAM End to end 1 hr 45 min 260 Graft Not repaired I hr 50 min 225 ~ Graft End to end 1 hr 55 rain 225 Advcnticiectomy Not revascularized End to end 2 hr 10 rain 250 End to end Not repaired 1 hr 35 rain 220 End to end Not revascularized Lon~.,term patency -P -O -O -P -P -P -O -P -O -P Comment Mild cold intolerance Slight loss of sensation Secondary Z-plasty Necrosed; amputation, MP joint Slight loss of sensibility 30 Flexion/contraction, PIP joint Necrosed; amputation, MP joint Fig. 2, E-F. Photographs 8 months after surgery, with full flexion and extension and normal functional use. Diagnosis is confirmed by Doppler evaluation digital ~ Allens test) esults or by a Of the four patients wi~o were misdiagnosed at initial evaluation and discharged, two did not heed subsequent symptoms of progressive neurologic and vascular deficit, which resulted in necrosis of the digit and amputation at or near the MP joint level (Fig. 3). The three patients who were correctly diagnosed initially and the. two patients who sought further medical care within 8.5 hours of initial injury because of progressive symptoms of numbness, coldness, pain, and color change had surgical exploration. Essentially similar surgical findings were noted in all. The two patients whose condition had progressed to complete digital necrosis prior to reevaluation had amputations performed. Both showed digital arteries divided at the level of the proximal transverse digital arteries. In the five digits revascularized, all ten digital arteries were nonpatent: Seven vessels were completely divided, two were thrombosed, and one was in spasm that was :relieved by local adventiciectomy. All pathology was located at or just distal to the origin of the proximal transverse digital artery. Seven digital arteries were repaired. Five required only resection of damaged vessel and direct end-to-end repair. 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-

5 814 Nissenbaum The Journa~ : f HAND SGEI,:y Vol. 9A, Novembe Fig. 3. Case 4. A 32-year-old man with mechanism of injury and initial pathology similar to that in case 1, with palmar skin-laceration repaired in an emergency room after which the patient was discharged. Full OM and normal sensibility were recorded by initial examiner 1 hour after injury. Patient did not seek additional medical attention until irreversible necrosis was established. tensive tension-free mobilization, and large apparent gaps in the digital arteries could be overcome without the need for reversed vein graft or severe joint flexion. Direct end-to-end repair was performed in the last three patients (five arteries). Anticoagulation consisted of aspirin before and after surgery and low-molecular-weight dextran during and 2 days after surgery. All patients remained on oral aspirin, 300 mg/day, for 3 weeks after surgery. Immobilization after surgery consisted of a dorsal splint that maintained the digit in enough flexion to eliminate tension on the arterial repairs, never more than 30 at the MP and PIP joints. Early flexion in the splint was allowed and immobilization was discontinued after 2 weeks. On follow-up, all revascularized digits survived. Ave} age TAM was 240. Digits that showed some digital nerve contusion had slightly altered sensibility but none showed greater than 6 mm of two-point discrimination. Minimal symptoms of cold intolerance that decreased with time and local scar problems (one required secondary Z-plasty) were the only residual effects. All patients were performing all activities they were before injury without limitations. Evaluation of patency rates showed that at least one repaired digital vessel remained patent in each digit. Of the nine vessels repaired, six remained patent to digital Aliens test and directional Doppler evaluation. OIG. A. A5 -C3 DIG. A. -- C2 A3 POX DIG. A. - A2 B. TO VLS Fig. 4. Tendon sheath and digital vessels demonstrate proximal transverse digital artery. Clinically, these branches are often 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 digital arte13~. (eproduced, with permission, from Schneider LH. Hunter JM: Flexor Tendons--Late reconstruction. In Greet DP, editors: Operative hand surgery. New York, 1982, Churchill Livingstone, pp Discussi,an Edwards 5 first described the proximal, intermediate, and distal transverse arterial branches that consistently arise from each digital artery. The proximal transverse digital artery enters the flexor tendon sheath just distal to the A-2 pulley. It arises at almost a right angle, tethering the digital artery just at the level of maximai force exerted by the ring finger. This prevents distal migration of the vessels with other soft tissues. Dorsal branches of the digital nerve at this level arise obliquely and corn greater e The e: ring dep~ the patie the mect at greate minimal This 1 rare one examina evaluati~ arterial ~ intact, n vascular It is d survived showed gressive sensibili capillar3 In di~ juries w

6 Vol. 9A, No. 6 November 1984 Class I1A ring avulsion injuries 815 and course primarily towards the skin, allowing much greater excursion-of the nerve (Fig. 4). The extent of damage from longitudinal traction on a ring depends on the tightness of the ring, the weight of the patient, the period, of time the force is applied, and the mechanism of injury. The tethered digital artery is at greater risk and can be divided or thrombosed with minimal or no injury to other structures. This lesion is not, as current literature suggests, a rare one. Awareness of the entity and careful initial examination by the digital Aliens test or by Doppler evaluation should lead to early exploration and simple arterial repair. Since all other anatomic structures are intact, near normal function can be expected after revascularization. It is doubtful whether any of these digits would have survived had not arterial repair been performed. All showed some degree of dorsal contusion and had progressive ischemic changes characterized by decreasing sensibility and temperature, increasing pain, and loss of capillary refill. In 5 digital amputation or class III ring avulsion in juries with compromised function of the joints, ten- dons, and nerves, injudicious replantation may result in a parasitic member that "only the patient could love." evascularization ~f class IIA ring avulsion injury, however, :results in as close to a normal digit as possible. Since failure to operate usually results in digital loss, this situation creates a strong indication for microvascuhtr repair. EFEENCES 1. rbaniak J, Evans JP, Bright DS: Microvascular management of ring avulsion injuries. J H,~No Su~ 6:25-30, Flagg S V, Finseth FJ, Kinzek TJ: ing avulsion injury. Plast econstr Surg 59:241-6, Comtet JJ, Willens P, Moura~ P: ing injury with bilateral rupture of the digital arteries without skin damage. J H~r~ Su~ 4:415-6, Evans D: Letter to the editor. J HAND SG 5:294, Edwards EA: Organization of the small arteries of the, hand and digits. Am J Surg 99:837, Lister G: The hand: Diagnosis and indications. London, 19 77, Churchill Livingstone, p Littler JW: On making a thumb: one hundred years of surgical[ effort. J HAlo St~ 1:35-51, 1976