Correction of camptodactyly

CORRECTION

OF CAMPTODACTYLY

Preliminary results of extensor indicis transfer A. GUPTA and F. D. BURKE From the Hand Unit, Derbyshire Royal Infirmary, Derby Extensor indicis proprius has been used as a transfer to overcome passively correctable camptodactyly. The transferred tendon is accessible, expendable and synchronous. Early results are encouraging. Journal of Hand Surgery (British Volume, 1990) 15B: 168-170

Camptodactyly occurs in less than 1% of the population (Jones, Marmor and Lankford, 1974). Engber and Flatt (1977) stated that camptodactyly may present as an isolated finding or as part of a multi-system syndrome. In their series, 84% of patients had deformity in the first year of life and only about 10% developed the condition after the age of ten. Wood (1988) believes that camptodactyly if left untreated will get progressively worse in about 80% of cases. Virtually every structure at the base of the finger has been implicated in the pathogenesis (Smith and Kaplan, 1968). It is, therefore hardly surprising that many types of treatment have been tried. These include conservative management with splints (Hori et al., 1977), cervicodorsal sympathectomy, skin release and Z-plasties, capsular release, release of collateral ligaments, lengthening of the flexor digitorum superficialis or profundus tendons, resection of lumbricals, tendon transfers, osteotomies, arthroplasties and arthrodesis. We report the preliminary results of a new operation to correct camptodactyly. We have used the extensor indicis proprius and transferred it through the lumbrical canal, deep to the transverse metacarpal ligament, to the radial side of the extensor expansion in an attempt to strengthen the intrinsic action to the little finger to produce flexion at the M.P. joint and extension at the P.I.P. joint. The transfer is only appropriate in cases with correctable deformity at the P.I.P. joint, i.e. those in which, if hyperextension of the M.P. joint is prevented, the patient can achieve full or nearly full active extension at the P.I.P. joint.

Operative procedure

A straight volar incision is made over the P.I.P. joint and a series of Z-plasties constructed. Longitudinal fibres of the digital fascia are divided, preserving the neurovascular bundles. The digital sheath is inspected to identify any abnormal intrinsic insertions. If any abnormal intrinsics are found, these are released. The extensor indicis proprius tendon is identified over the second M.P. joint through an oblique incision. This tendon is divided just proximal to the expansion, withdrawn to wrist level and passed slightly radial to the 168

fifth ray. The tendon is brought out through an incision over the fifth metacarpal shaft. An incision is then made over the radial aspect of the extensor expansion of the little finger. A haemostat is passed proximally along the lumbrical canal (palmar to the intermetacarpal ligament) and then dorsally between the fourth and fifth metacarpals to meet the transferred E.I.P. tendon. The E.I.P. tendon is thus passed palmar to the intermetacarpal ligament and then braided into the radial intrinsic or the central slip of the little finger (Fig. 1). If traction on the radial intrinsic does not produce satisfactory joint extension, the transfer is sutured to the communis tendon or the central slip. Tension is adjusted with the tenodesis test (wrist flexion producing M.P. flexion and I.P. extension). The hand is rested on a volar slab in the safe position (wrist extension, M.P. flexion and I.P. extension) for four weeks, followed by a further two-week period regaining digital flexion with an extension block splint which maintains 40” of flexion at the M.P. joint. Case reports Case 1

A 15year-old girl presented with camptodactyly involving the left little finger, with 40” hyperextension at the M.P. joint and 50” correctable flexion deformity at the P.I.P. joint (Fig. 2). An E.I.P. transfer to the central slip of the extensor tendon in the little finger was carried out. Post-operatively, the patient used a Capener splint for eight weeks. She was reviewed one year after the operation, when the result was graded as excellent. She had no cosmetic deformity, and full active flexion and extension at the M.P. and P.I.P. joints (Fig. 3). She also retained independent extension of her index finger.

Fig. 1

Drawing

of the operation. THE JOURNAL OF HAND SURGERY

CORRECTION

OF CAMPTODACTYLY

little finger was held flexed at 90”, with no hyperextension of the M.P. joint. The deformity was not correctable. The left little finger was 50” flexed at the P.I.P. joint, which was partially correctable. The patient underwent E.I.P. transfer on the left little finger with a volar Z-plasty. A Capener splint was used for a month afterwards. When reviewed recently, 18 months after operation, he had full active extension and flexion at the M.P. and P.I.P. joints with no deformity. The result was graded excellent. The P.I.P. joint of his right little finger was fused in a position of mid extension, with improvement in appearance and function. Discussion Fig. 2

Case l-deformity

before operation.

Cme 2 A 13-year-old girl was referred with a progressive camptodactyly of the right little finger. There was a 50” flexion deformity at the P.I.P. joint which was correctable except for the last 20”. The patient underwent an E.I.P. transfer, after which the finger was splinted for three months. The initial correction was to 20” of flexion deformity at the P.I.P. joint and this was maintained three months later. Nine months after operation, this had deteriorated a little to 30”, with hyperextension of 10”at the M.P. joint. The PIP. joint was, however, fully actively correctable on flexion of the M.P. joint. Case 3 A 13-year-old boy was seen with severe bilateral camptodactyly. On the right side, the P.I.P. joint of the

Fig. 3

VOL.

(a & b) Case l-range

15B No. 2 MAY

1990

of movements

Camptodactyly is relatively uncommon and remains difficult to treat. According to Wood (1988) there is no single standard successful treatment because there is no single identifiable cause for this condition. Fortunately, in a large majority of patients, the deformity remains mild (Engber and Flatt, 1977) and no treatment is required, as the patient accepts the deformity and learns to live with it. In other cases, however, there is worsening of the deformity during the adolescent growth spurt. Courtemanche (1969) described the anomalous insertion of the fourth lumbrical. This seemed to cause the deformity. Smith and Kaplan (1968) felt that contracture of the flexor digitorum superficialis initiates the flexion deformity. Flexion of the wrist and M.P. joint allow P.I.P. extension. In patients exhibiting this sign, they performed tenotomy of the superficialis tendon. In 12 patients reported, the flexion contracture was reduced by at least 33%. Millesi (1974) felt that the deformity was due to an imbalance between flexing and extending forces due to a weak area in the extensor aponeurosis over the P.I.P.

a year after the operation.

169

A. GUPTA

AND

joint. He performed a volar release, coupled with transfer of the flexor digitorum superficialis to the extensor aponeurosis. McFarlane et al. (1983) also believe that there is an imbalance between the flexor and extensor forces acting upon the P.I.P. joint. In 21 operations, they found abnormal lumbricals giving rise to an intrinsic minus deformity. Based on these findings, they have used soft tissue releases combined with tendon transfers to restore intrinsic action and maintain correction of the deformity. These authors recommend transferring the flexor digitorum superficialis of the ring finger to the extensor of the little finger. Transfer of the superficialis of the little finger gave disappointing results in their series: this tendon is frequently part of the superficialis of the ring finger and thus may lack independent action. We believe that the primary deformity in camptodactyly is an imbalance between the flexors and the extensors, possibly as a result of abnormal intrinsics giving rise to intrinsic-minus deformity. The capsular and skin contractures are secondary. We have used the extensor indicis transfer to the radial side of the extensor of the little finger to supplement intrinsic action in flexible camptodactyly. In certain circumstances, this transfer may have to be combined with palmar surface release and division of an abnormal lumbrical if one is found. The early results are promising. The tendon chosen for

170

F. D. BURKE

the transfer is accessible, synchronous and more readily spared than a superficial flexor. References COURTEMANCHE, A. D. (1969). Camptodactyly; etiology and management, Plastic and Reconstructive Surgery. 44: 451-454. ENGBER, W. D. and FLATT, A. E. (1977). Camptodactyly: An Analysis of sixty-six patients and twenty-four operations. Journal of Hand Surgery, 2: 3: 216-224. HORI, M., NAKAMURA, R. INOUE, G., IMAMURA, T., HORII, E., TANAKA, Y. and MIURA, T. (1987). Nonoperative treatment of camptodactyly. Journalof Hand Surgery, 12A: 6: 1061-1065. JONES, K. G., MARMOR, L. and LANKFORD, L. L. (1974). An overview on New Procedures in Surgery of the Hand. Clinical Orthopaedics and Related Research, 99: 154-167. MAEDA, M. and MATSUI, T. (1985). Camptodactyly Caused by an Abnormal Lumbrical Muscle. Journal of Hand Surgery, 10B: 1: 95-96. McFARLANE, R. M., CURRY, G. I. and EVANS, H. B. (1983). Anomalies of the intrinsic muscles in camptodactyly. Journal of Hand Surgery, 8: 5(l): 531-544. MILLESI, H. Camptodactyly. In: Littler, J. W., Cramer, L. M. and Smith, J. W. (Eds.) Symposium on Reconstructit;e Hand Surgery. St. Louis, C. V. Mosby, 1974: 175-177. MUIRA, T. (1983). Non-traumatic flexion deformity of the proximal interphalangeal joint-its pathogenesis and treatment. The Hand, 15: 1: 25-34. SMITH, R. J. and KAPLAN, E. B. (1968). Camptodactyly and Similar Atraumatic Flexion Deformities of the Proximal Interphalangeal Joints of the Fingers. Journal of Bone and Joint Surgery, SOA: 6: 11X7-1203. WOOD, V. E. (1988). Camptodactyly. In: Green, D. P. (Ed.) Operative Hand Surgery (2nd edn.) New York, Churchill Livingstone, 1988 : Vol 1: 409-416.

Accepted: 5 May 1989 Mr. F. D. Burke, The Hand

Unit,

0 1990 The British

for Surgery

Society

Derbyshire

Royal Infimmy,

London Road, Derby.

of the Hand

02667681/90/00154168/%10.00

THE

JOURNAL

OF HAND

SURGERY