Opponensplasty--an experience of twenty-three cases using three techniques.

RR Bindra, DS Bhandarkar, JC Taraporvala 
 Department of Orthopaedics, J. J. Hospital, Bombay, Maharashtra.

Correspondence Address:
R R Bindra
Department of Orthopaedics, J. J. Hospital, Bombay, Maharashtra.

Full Text

::   Introduction

The human hand is specially adapted for the prehensile functions of pinch and grip. These are carried out by an effective thumb opposition, which is a complex movement with motion in several planes produced by a combination of: (a) extension of thumb by extensor pollicis longus and extensor pollicis brevis, (b) abduction of the thumb by the abductor pollicis longus and abductor pollicis brevis and (c) pronation of the thumb by opponens pollicis and flexor pollicis brevis[6]. The loss of thumb amounts to a significant functional disability. Various techniques have been described to restore the opposition of thumb. Here we present a series of twenty-three cases of opponensplasties carried out at The Hand Clinic of the Department of Orthopaedics, JJ Hospital, Mumbai.

We used three standard techniques in twenty-one opponensplasties and our own modification of the third Myer Makin's procedure[3] in two opponensplasties. We report this series because (a) there are only two published Indian series[4],[7] on this topic, (b) we describe a modification of Myer Makin's procedure, and (c) we wish to suggest that it is almost always possible to devise a surgical procedure to restore the opposition of the thumb.

::   Material and method

A total of 21 patients (17 males, 4 females; age ranging from 10 to 45 years, mean 27.5 years) underwent 23 opponensplasties; two patients underwent bilateral operation. There were 13 operations on the right hand and 10 on the left.

Nine patients underwent surgery for leprous neuritis, 3 for poliomyelitis, 1 for motor neurone disease, 1 for Charcot Marie Tooth syndrome, 5 for trauma and its sequelae, and 2 for congenital hypoplastic thumb.

Physiotherapy was begun pre-operatively in all cases to correct tightness of the thumb web. All the patients with leprosy were given at least six months of chemotherapy prior to surgery. One patient with Volkmann's ischaemic contracture underwent a muscle slide, and 1 patient underwent fixation of forearm fractures pre-operatively.

The three techniques used for opponensplasty were;

1. Flexor sublimis transfer (modified Riordan's technique)[5] (See [Figure:1])

2. Brachioradialis transfer[1] (See [Figure:2])

and

3. Meyer Makin's opponensplasty[3].

We used a modification of the Myer Makin's opponensplasty procedure avoiding the osteotomy. Instead, the flexor pollicis tendon was lengthened by a 'z' plasty; the proximal slip was then wound around the proximal phalanx of the thumb and sutured to the distal slip, thereby achieving a translocation of the tendon (See [Figure:3])

Post-operatively, a plaster of paris thumb spica was applied for three weeks, followed by an opponens splint and physiotherapy for three months.

All the cases were followed up for one to three years. The results were graded using the criteria described as follows:[7]

Excellent: Pulp of thumb can oppose to pulp of little or ring finger with the thumb interphalangeal joint extended.

Good: Pulp of thumb can oppose to pulp of middle or index finger with the thumb interphalangeal joint extended.

Fair: Thumb opposition possible only with the thumb interphalangeal joint flexed.

Poor: No opposition.

::   Results

The outcome of opponensplasties on 23 thumbs are illustrated in [Table:1]; 13 had excellent results, 6 had good results, 3 had fair results and only one had a poor result. According to the power of pinch of the patients another grading was also carried out. The function was good in 14 hands, fair in 7 hands and poor in 2 hands.

No major complication was noted in any patient. The minor complications were as follows: the pulley slipped in one hand of flexor sublimis transfer resulting in weakness of opposition; 1 hand of brachioradialis transfer developed subluxation of metacarpophalangeal joint; and 2 hands of Makin's transfer done with osteotomy of proximal phalanx of the thumb developed non-union of the osteotomy requiring subsequent bonegrafting and ‘K’ wire fixation.

::   Discussion

The restoration of opposition is frequently only one step in the rehabilitation of the upper extremity as a whole. This has to be supplemented by subsequent tendon transfers for restoration of other intrinsic functions of hand wherever required.

Various techniques have been described to restore opposition of the thumb but the following points as 2 described by Jacobs and Thompson must be carefully observed to get good results.

1) All soft tissue contractures must be corrected, if necessary by surgery, before attempting opponensplasty.

2) The joints of the thumb must be freely mobile.

3) An appropriate motor muscle, suitable in each case, must be selected.

4) To produce true opposition, it is desirable to construct a pulley, which is fixed securely, provides correct direction of pull and is at a sufficient distance from the thumb to permit enough excursion of the transferred tendon.

5) The motor tendon must pass subcutaneously towards the pisiform bone and then into the thumb; and

6) The transfer-red tendon should be inserted on the dorso ulnar aspect of the base of the proximal phalanx of the thumb.

In the series of opponensplasties by Palande[4] 86 patients with leprous neuritis resulting in paralysis of intrinsic muscles of hand underwent a modified Bunell opponensplasty. Good results were obtained in 18 cases, fair results in 63 cases and poor results in 5 cases. The poor results were attributed to infection, weakness or deformity.

Sundararaj and Mani[7] reported a series of 24 cases in which 20 patients underwent flexor sublimis transfer, 3 under went pollicis longus transfer and 1 case cussed under Material And Method, to was treated by arthodesis of the meta-carpo-phalangeal joint of the thumb. They had 15 excellent, 6 good and 3 fair results.

In our series, flexor sublimis tendon, when available, was used to give satisfactory results. In the absence of a suitable flexor sublimis tendon, brachioradialis was utilised and good results were obtained. However, when the above muscles were not available as in Volkmann's ischaemic contracture, translocation of the flexor pollicis tendon proved to be the best alternative. The resultant weakness of the interphalangeal joint of the thumb after this translocation does not constitute a serious disability as the most activities are carried out with the proximal interphalangeal joint in extension. As non-union of the osteotomy of the proximal phalanx of the thumb occurred in the first two cases operated upon by Myer Makin's technique, we modified the procedure, as discussed under Material And Method, to avoid such non-union.

References