Evaluation of a uniform operative technique to treat syndactyly

Twenty-two patients with upper extremity syndactyly (58 webs) have been treated in the last decade (1976 to 1985) by one hand surgeon using one technique. Nineteen patients had syndrome complexes or other associated anomalies that made treatment more difficult. The postoperative follow-up averaged 4 years. The rate of complications that necessitated repeat operations (5% of the treated webs) was relatively low in comparison with those in other series. We attribute this to better timing of the procedure and progressive experience gained by one surgeon using the same procedure. (J HAND SURG 1987;12A[2 Pt 1]:727-9.)

David Keret, M.D., and Errol Ger, M .D. , Wilmington, DeL.

Syndactyly of the fingers is one of the most common congenital anomalies of the hand; it ap­pears in one of 2500 births. I It is frequently associated with other congenital anomalies of the upper and lower limbs. Syndactyly represents a failure of separation of the developing mesenchymal structures ,2 which nor­mally occurs between the fifth and eighth weeks in utero. 3 Inheritance is most often autosomal domi­nant,4 although several forms of genetic behavior have been observed. 5-8

In 1979 we reported the results of operative treatment of 61 patients with 176 webs using three different sur­gical procedures. I The present series represents the lO-year experience of one surgeon (E. G.) with a single procedure.

Materials and methods

Since 1976, 22 patients with 58 webs have been uniformly surgically treated and followed-up at the Alfred I. duPont Institute.

There were 11 males and 11 females in the series. Syndactyly was unilateral in 14 (64%) patients with seven right hands and seven left hands involved. Eight

From the Alfred I. duPont Institute , Wilmington, Del.

Received for publication May 22, 1986; accepted in revised form Oct. 7, 1986.

No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article .

Reprint requests: Errol Ger, M.D., 2401 Pennsylvania Ave., Suite 115, Wilmington, DE 19806.

Fig. 1. In complete syndactyly the webbing includes the tips of the fingers. In this patient, poly syndactyly was associated with duplication of both thumbs .

Fig. 2. Radiograph of bilateral complex syndactyly. The left hand shows poly syndactyly, with bone structures for an extra digit. The right hand shows fusion of the phalanges.

THE JOURNAL OF HAND SURGERY 727

728 Keret and Ger

Fig. 3. The procedure used in this series is a modification by Flatt of the procedure first described by Cronin. A, Palmar and dorsal multiple zig-zag incisions. B, The resulting flaps are approximated to cover the entire length of the digits, with a single, broad, dorsal rectangular flap between the fingers ' to join the palmar incision.

(36%) patients had bilateral syndactyly. Of 30 involved hands, there were II with one affected web, 10 with two, seven with three, and two with four affected webs. The long-ring web was most frequently involved (43%) followed by the index-long web (31 %), ring-small web (21 %), and thumb-index web (5%).

Clinical analysis showed 33 (57%) of the syndac­tylies were incomplete, while 25 (43%) were complete (Fig, 1). Radiographic examination showed that 39 (67%) were simple, while 19 (33%) were complex (Fig. 2) (Table I). Of the 58 webs , only 11 (19%) were the complete-complex type. A positive family history was identified in 23% of the patients; one patient was from a family with a six-generation history of syn­dactyly.

Syndactyly was seen in association with a syndrome complex in nine patients (41 %), in six with congenital constriction band syndrome (Streeter's syndrome), and in three with Poland's syndrome. Ten patients had one or more associated congenital anomalies that included hypoplasia of the hand or arm (4), polysyndactyly of a hand and/or foot (4), brachydactyly (3), absent pha­langes or digits (3), clinodactyly (2), and macrodactyly

The Journal of HAND SURGERY

Table I. Clinical and radiographic classification of syndactyly (58 webs)

Clinical Incomplete Complete

Radiographic

Simple Complex

25 14

8 II

(all four extremities), duplication of thumb, vertical talus, bilateral clubfeet, and hypoplasia of the lower limb (one each). Only three patients had syndactyly without any associated anomaly.

Surgical procedure

The surgical procedure used in this series for the release of syndactyly was first described by Cronin,9' 10 modified by Bauer and associates, II then further modified by F1att l2 (Fig. 3).

Multiple zig-zag incisions were made on the palmar and dorsal aspects of the hand. The subcutaneous tissue was divided by sharp and blunt dissection. Care was taken not to damage the neurovascular bundles. A sin­gle, broad, dorsal rectangular flap was used to join the transverse incision in the palm. Excess fat was trimmed away. Any skin defect was covered by full-thickness skin graft (after defatting) taken from the left lateral groin region. When two adjacent webs were involved, both were not released at the same sitting. However, if there were three or four adjacent webs involved, alter­nate webs were freed at the same time. A sterile dressing was applied to the incision and inserted deep between the fingers to keep them separated until healed. The upper extremity was held in an above elbow cast from the distal phalanges to the upper arm . .

Results

Thirty-three surgical procedures were performed in 22 patients for release of the syndactyly. All patients were treated surgically by means of the procedure de­scribed. There were eight patients who had multiple webs released at one sitting. Other simultaneous pro­cedures were performed for associated anomalies when necessary; these included ablation of rudimentary fin­gers or phalanges (three patients), epiphysiodesis of growth plates (one patient), and osteotomy (one pa­tient). A full-thickness skin graft was used in all but one patient where primary closure of both separated fingers was possible.

The age of patients at operation ranged from 6 months to 7 years and 3 months, with an average of 2 years

Vol. 12A, No.5, Part 1 September 1987

and 3 months. The age distribution at the time of initial release of the syndactyly was as follows: one patient underwent operation at 6 months of age, 19 patients between 1 and 3 years of age, and two who were more than 5 years of age (due to delayed referral).

Postoperative follow-up averaged 4 years, with a range of 3 months to 9 years; all but two patients were followed-up for a minimum of 1 year.

There was one early postoperative complication; a tiny sinus that resolved after a short period of conser­vative treatment. No hyperpigmentation or hair was noticed to affect the cosmetic appearance of the skin graft.

Three patients required repeat procedures; two to treat skin contractures and one for treatment of partial web recurrence. A repeat procedure was deemed nec­essary for recurrence of a web that extended up to the level of the proximal interphalangeal joint. The one web recurrence in our series was due to poor bandaging postoperatively; the gauze was not inserted deeply enough in the newly formed commissure and was re­moved too early, leaving behind raw interdigital sur­faces that led to adhesions and recurrent iatrogenic syn­dactyly.

Of the three patients who required revision proce­dures, one had complete-complex syndactyly and un­derwent operation three times, with an unfavorable end result. The other two patients both had complex web­bing that might have contributed to the need for addi­tional procedures; one of these patients had residual flexion contractures of both separated fingers.

Discussion

Syndactyly can lead to significant functional prob­lems. The aim of surgery is to construct a commissure and proper web between the affected fingers to improve function and appearance.

Our experience, and that of others, suggests that pa­tients with complete-complex syndactyly are likely to have a better functional result if the bony separation is performed early, usually within the first year of life; whereas, with simple syndactyly, surgical treatment can be delayed until later in the preschool period.

The associated congenital anomalies are often more significant than the syndactyly and may require im­mediate attention. This led to delay of treatment beyond 18 months of age in several of our patients. Further­more, five patients in our series had concurrent pro­cedures for associated hand anomalies at the time of web release.

Operative technique to treat syndactyly 729

The results of our earlier series' and those of other authors9

. 10 favored the use of the Flatt technique, using a full-thickness skin graft to fill the defect at the sides of the fingers. In this series, only three of the surgically treated webs (5%) had contracture and significant re­currence that necessitated further surgical procedures. This relatively low percentage is different from the 52% and 30% rates of repeat surgery in the two groups in our previous series. BrownS reported a 45% incidence of more than one operation to correct syndactyly.

The present series of patients included a comparable number of "difficult" cases (i.e., those with complete­complex syndactyly and those with other major asso­ciated anomalies) as in our previous report. We con­tribute our low incidence of complications (and the need for a second procedure) to two factors : first, better tim­ing in the release of the syndactyly, and second, in­creased skill from the experience gained by the same surgeon using the same procedure in all cases.

REFERENCES

1. Toledo LC, Ger E. Evaluation of the operative treatment of syndactyly. J HAND SURG 1979;4:556-64.

2. Smith RJ. Osteotomy for "delta-phalanx" deformity. Clin Orthop 1977;123:91-4.

3. Entin MA. Syndactyly of the upper limb; morphogenesis , classification and management. Clin Plast Surg 1976; 3:129-40.

4. Rayner CR. Inheritance of syndactyly. Br J Plast Surg 1972;25:454-6.

5. Brown PM. Syndactyly, a review and long term results. Hand 1977;9:16-27.

6. Straus WL. Nature and inheritance of webbed toes in man. J MorphoI1925;41:427-39.

7. Barsky AJ. Congenital anomalies of the hand. J Bone Joint Surg [Am) 1951 ;33:35-64.

8. Dobyns JH. Syndactyly. In: Green DP, ed. Operative hand surgery. New York: Churchill Livingstone 1982: 281-301.

9. Cronin TO. Syndactylism: Experiences in its correction. Tri-State Med J 1943;15:2869-71.

10. Cronin TO. Syndactylism: results of zig-zag incision to prevent postoperative contracture. Plast Reconstr Surg 1956;18:460-8.

II. Bauer TB, Tondra JM, Trusler HM. Technical modifi­cation in repair of syndactylism. Plast Reconstr Surg 1956; 17:385-92.

12. Flatt AE. Practical factors in the treatment of syndactyly. In: Littler JW, Cramer LM, Smith JW, ed. Symposium on reconstructive hand surgery. St. Louis: The CV Mosby Company, 1974:144-56.