Replantation of ring avulsion of index, long, and ring fingers

Results of replantation of 33 ring avulsion amputations

PURPOSE

Despite microsurgical advances, it is still difficult to achieve satisfactory functional results in cases of replantations following complete ring avulsion amputations. Our aim is to report the experience we have collected since the early 1990s in the treatment of this type of injury.

METHODS

We replanted 33 fingers on 33 patients (age, 15-54 y) with complete ring avulsion amputation injuries. Twenty-eight amputations were distal to the insertion of the flexor digitorum superficialis, and 5 were complete degloving injuries with intact tendons. Vascular transpositions and vein grafts were used, and in all cases, only 1 of the digital nerves was repaired.

RESULTS

The 29 successful cases were tracked over an average follow-up of 89 months. The average total active motion of the reconstructed finger was 185°. Sensibility evaluated by static 2-point discrimination varied from 9 to 15 mm and by moving 2-point discrimination from 8 to 15 mm. Five patients complained of cold intolerance.

CONCLUSIONS

Resection of the avulsed digital artery and vein is the most crucial part of the procedure.Vessels reconstruction can be performed using various methods, but vessel transfers from the middle finger appear to be the most reliable solution. The outcome of the cases demonstrates that replantation should be attempted.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Limb replantation after avulsion injuries: techniques and tactics for success

Objectives

Retrospective evaluation of cases of limb replantation after avulsion injuries. Evaluation of the techniques and tactics used, that contributed to success and good functional results.

Methods

Forty-three patients' records were assessed. All the cases had been submitted to limb replantation after avulsion injuries.

Results

The majority of the cases were young men. The most common injury was to the thumbs. The surgical techniques and tactics used were: nerve grafting, vein grafting, transposition of the digital vessels, limb shortening, and heterotopic replantation. The most commonly used technique was vein graft. The limb survival rate was high (93%), as was patient satisfaction.

Conclusion

Replantation after avulsion injury depends on the correct diagnosis of the limb viability and the use of appropriate surgical techniques and tactics for each case. The experience of the team of surgeons and a good hospital structure are essential for good results. There are few articles in medical literature about the indications, techniques and results of limb replantation after avulsion injuries. We believe that this retrospective evaluation can bring new information and contributions to the correct management of this highly complex situation. Level of evidence IV, Case Series.

Reconstruction of a degloved finger with a heterodigital reverse dorsal digitometacarpal flap

We used a reverse dorsal digitometacarpal flap to reconstruct a degloved finger in a 60-year-old patient who had an avulsion digital amputation. The digitometacarpal island dorsal flap was raised on the vascular axis of the ring finger and wrapped around the degloved little finger. The long term results were good.

Unique superiority of microsurgical repair technique with its functional and aesthetic outcomes in ring avulsion injuries

Although ring avulsion injuries are not common, when they do occur their management is still a challenging problem in reconstructive surgery. In this report, we present our microsurgical experiences with Kay's class III and IV ring avulsion injuries. A total of six patients with ring avulsion injuries were operated on between 2000 and 2004. Three patients were in class III with inadequacy of both arterial and venous circulation, and the remaining three were in class IV. The study consisted of four male and two female patients whose ages ranged from 23 to 43 (mean age 32). Average ischaemic time was 2.2 h (range 1-4 h). The ring finger was involved in all cases and microsurgical repair was performed using axillary block anaesthesia. The bone was detached at the level of the distal interphalangeal joint and soft tissues at the proximal phalanx level with the preserved proximal interphalangeal joint and flexor digitorum superficialis tendon in all cases. Because the zone of injury is more extensive, we debrided the avulsed digital artery over a long distance, and used long interpositional vein grafts radically in all patients. Venous drainage was accomplished by performing at least two vein anastomoses using vein grafts when necessary. Both digital nerves were repaired primarily after debridement. Results indicated that microsurgical repair had a success rate of 100%. The authors conclude that microsurgical reconstruction of ring avulsion injuries with intact proximal interphalangeal joint and flexor digitorum superficialis tendon yields superior results, both functionally and aesthetically, even in complete amputation.

Ring avulsion replantation by extended debridement of the avulsed digital artery and interposition with long venous grafts

Ring avulsion replantation is a technically challenging procedure with a very low success rate. Because the zone of arterial injury is more extensive than what it appears to be in such avulsion amputations, a technique was developed to debride the avulsed digital artery for a long distance, extending well into the digital pulp, thereby creating healthy arterial ends to be bridged by one or two segments of long venous grafts. Using this technical approach, 7 patients with complete amputations of ring avulsion injury (Urbaniak's class III) were operated. In all amputations the bone was disrupted at the distal interphalangeal level (except in 1 patient) and the soft tissues at the proximal phalanx level, with the proximal interphalangeal joint and the flexor digitorum superficialis tendons being intact. Results indicated that replantation was successful in all patients. However, 2 patients presented with unusually late arterial failure 28 and 30 days after surgery respectively. Although one of these cases was salvaged by reoperation, the other case (followed by conservative management) demonstrated partial distal necrosis. Therefore, the ultimate success rate in this series was 85% in the long term. At follow-up, sensibility was protective in all patients, with an average static two-point discrimination of 7.8 mm (range, 6-14 mm). The total active motion of the replanted digits was 194 deg on average (range, 155-205 deg) without loss of function of the proximal interphalangeal joint except in 2 patients who had late vascular problems. The authors conclude that microsurgical replantation of completely amputated ring avulsion injuries with an intact proximal interphalangeal joint and flexor digitorum superficialis tendon, is a worthwhile procedure that results in good functional and aesthetic results. Furthermore, using an aggressive approach for debridement of the avulsed digital artery, as described in this article, an experienced microsurgeon can replant successfully nearly all cases. However, one should be cautious in the follow-up of such patients, because late arterial failure may be encountered, as was observed in 2 patients in this series. The authors suggest immediate reoperation in such unusual circumstances.

Secondary surgery after digit replantation: its incidence and sequence

This article discusses the incidence and sequence of secondary procedures following digital replantation. In published series addressing this topic, the overall frequency of postreplantation surgery ranged from 2.9-93.2%. Tendon procedures accounted for 47.2% of cases, and comprised the leading type of secondary operations. Tendon procedures were followed by joint procedures (18.9%), skeletal stabilization (12%), skin coverage (11.4%), nerve reconstruction (8.9%), and late amputation (1.6%). The number of secondary procedures per patient averaged from 1-4.5, depending on prioritization of different procedures. The order of restoration procedures should be as follows: supple skin coverage, skeletal stability, and protective and proprioceptive sensation. Joint reconstruction follows these procedures, which in turn is followed by tendon reconstruction.

[Aseptic bone necrosis following reimplantation of a degloving finger]

We report a case of microsurgical replantation of a degloved finger in a manual worker. Four months following replantation, avascular necrosis of the middle and distal phalanges was apparent. Amputation at the level of the proximal phalanx was performed. Re-plantation is the solution of choice for such degloving injuries, but a different flap can be used if replantation is not possible. Avascular necrosis of bone is an unfrequent complication, but surgeons should be aware of it.

The use of a thin abdominal flap in degloving finger injuries

Three multiple-finger degloving injuries were successfully resurfaced with thin abdominal flaps. This method offers immediate total wound coverage in multiple-finger degloving injuries.

Replantation

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Describe the indications and contraindications for extremity replantation. 2. Outline the sequence and technique of replantation. 3. Identify potential complications of replantation and recognize treatment options. 4. Assess the results of replantation in terms of function and costs versus benefits.

Salvage of completely degloved finger with a posterior interosseous free flap

The use of a free posterior interosseous skin flap should be considered in a single digit degloving injury, especially when replantation of the avulsed skin or the use of skin from the second toe, transferred as a composite-tissue flap, is not feasible. The flap is thin and pliable. It allows early mobilisation with good recovery of joint motion and attains protective sensation of the finger.

Preservation of a digital osteotendinous structure with an omental flap

Taking into account the angiogenic properties of the omentum to revascularize ischemic tissues, this experimental, longitudinal, prospective, double-blind study in rabbits was designed to revascularize and preserve the mobility of a digital osteotendinous structure surgically devascularized in advance and to compare such omental angiogenic ability with that of the muscle and the panniculus carnosus. Thirty New Zealand rabbits were used. Three toes from the hind feet were surgically amputated from each rabbit. The skin was removed, exposing the bones, tendons, ligaments, and joints, to form what we termed the osteotendinous structure. Through a median laparotomy, the first part of each rabbit's own osteotendinous structure was placed inside the panniculus carnosus (group I), the second under the rectus abdominis muscle (group II), and the third was wrapped in a pediculate omental flap (group III). Three weeks later, each structure was assessed clinically for mobility and fibrosis and microscopically for fibrosis, newly formed vessels, viability, and tissue regeneration. Clinically, the group I structures showed a greater amount of fibrosis. The structures in groups II and III showed minimal fibrosis in all but four cases, which showed moderate fibrosis. Differences in joint mobility were assessed with the Kruskal-Wallis test. There was a statistically significant difference in mobility for the structures from group III, which was higher, followed by those from groups II and I. The exception was the proximal interphalangeal joints in groups II and III, for which the differences had no statistical significance. Microscopically, fibrosis and tissue necrosis were intense in the structures in group I, moderate in the group II structures, and mild in the group III structures. Conversely, vessel neoformation and tissue regeneration were intense in the structures in group III, moderate in group II, and were nil in group I. This study confirms with statistical significance that, in the rabbit, the omentum has a higher ability to revascularize degloved tissues than do the muscle and the panniculus carnosus, thus preserving a higher joint and tendon mobility. Consequently, it is suggested that a free omental flap be used in the treatment of ring avulsion injuries that lead to degloving of the digits.

Ring avulsion injuries: a biomechanical study

The biomechanics of ring avulsion injuries was studied in a cadaveric simulation model. Custom-fitted metal rings attached to a rigid frame were placed over the proximal phalanx of fresh or thawed fresh-frozen specimens. Ring avulsion injuries in 44 fingers were produced with a standardized force applied to the proximal ulna. The progress of injury was evaluated with simultaneous high-speed cinematography and continuous force measurements. The injured digits were x-rayed and categorized according to Urbaniak's classification. Continuous force measurements produced similar curves for all classes of injuries. The average maximum force resulting in class I injuries was 80 N. The average maximum force producing amputation in class III injuries was 154 N, a force much lower than expected. Force measurements for class II injuries were nearly identical to those of class III. This surprisingly minimal force resulting in digit amputation was explained by high-speed cinematography, which showed that the rings tilt on the digits concentrating disruption forces as a result of ring angulation on the finger. Incomplete amputations were due to loss of ring purchase by skin flap eversion. Finally, comparison of high-speed cinematography with force curves suggests that skin rupture rather than skeletal or tendon disruption accounted for the maximum force during ring avulsion injury.