Final functional outcome in a case of wrist drop

Prasanta Kumar Bhattacharyya; Subhasish Ghosh; Arijit Roy; Manab Nandy

doi:10.4103/0794-9316.166849

CASE REPORT

Year : 2015 | Volume : 11 | Issue : 1 | Page : 29-31

Final functional outcome in a case of wrist drop

Prasanta Kumar Bhattacharyya¹, Subhasish Ghosh¹, Arijit Roy², Manab Nandy³
¹ Department of Plastic Surgery, KPC Medical College and Hospital, Kolkata, West Bengal, India
² Department of Surgery, KPC Medical College and Hospital, Kolkata, West Bengal, India
³ Department of Pharmacology, Calcutta National Medical College, Kolkata, West Bengal, India

Date of Web Publication

8-Oct-2015

Correspondence Address:
Manab Nandy
95B, Bidhannagar Road, HUDCO Housing Estate, Block 18, Flat 234, Kolkata - 700 054, West Bengal
India

Source of Support: None, Conflict of Interest: None

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DOI: 10.4103/0794-9316.166849

Abstract

Tendon transfers are used to restore balance and function to paralyzed, injured, or absent neuromuscular motor units. The goal is to improve the balance of a neurologically impaired hand. In the upper extremity, tendon transfers are most commonly used to restore function following injury to the radial, median, and ulnar nerves. We report the case of an Indian Border Security Force (BSF) jawan who had wrist drop following a bullet injury to the left upper arm.

Keywords: Flexor carpi radialis, flexor carpi ulnaris, pronator teres, radial nerve, tendon transfer

How to cite this article:
Bhattacharyya PK, Ghosh S, Roy A, Nandy M. Final functional outcome in a case of wrist drop. Nigerian J Plast Surg 2015;11:29-31

How to cite this URL:
Bhattacharyya PK, Ghosh S, Roy A, Nandy M. Final functional outcome in a case of wrist drop. Nigerian J Plast Surg [serial online] 2015 [cited 2023 Oct 2];11:29-31. Available from: https://www.njps.org/text.asp?2015/11/1/29/166849

Introduction

Grip is severely impaired following loss of radial nerve function as a result of loss of extension of the wrist, metacarpophalangeal joints, and thumb.^[1] If the radial nerve does not show neural recovery following conservative or surgical repair, tendon transfer is considered the standard treatment. Tendon transfer for radial nerve paralysis has 100 years of history, and any set of tendons that can be considered useful has been utilized for the purpose.^[2] However, only a few of these sets of tendon transfers are in common usage nowadays. To summarize, in all of them the pronator teres (PT) is used for the restoration of wrist dorsiflexion, while the flexor carpi radialis ( FCR), flexor carpi ulnaris (FCU), and flexor digitorum superficialis (FDS) are variably used in each for finger and thumb movements.^[3],[4]

Case Report

A 40-year-old Indian Border Security Force (BSF)jawan presented to us with the chief complaints of inability to extend his left wrist and digits for the past 6 months [Figure 1]. He had a history of bullet injury to the left upper arm 6 months earlier, after which he had undergone amputation of the left index finger.

Figure 1: Preoperative picture. Wrist drop

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The patient was planned for surgical correction of wrist drop. During surgery, the PT was detached from its site of insertion and sewn to the extensor carpi radialis brevis (ECRB)[Figure 2]. The FCU was rerouted and transferred to the extensor digitorum [Figure 3]. The postoperative period was uneventful. A long cock-up splint was used for 3 weeks and a short cock-up splint for 3 more weeks. At the end of 6 weeks, the patient could extend his left wrist and digits. The patient is doing well after 6 months follow-up, at the time of writing [Figure 4].

Figure 2: During surgery

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Figure 3: Surgery in progress

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Figure 4: Postoperative condition

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The final outcome can be seen in the video link available at: http://youtu.be/k15D7YYbvwo.

Discussion

An understanding of the general principles of tendon transfer is crucial for maximizing outcomes. These principles are as follows:

The functional loss associated with the use of the donor tendon should be minimized to maximize functional gains following transfer. The donor tendon must be expendable so that its removal will not result in unacceptable loss of function, and innervation must be intact ^[5],[6]
The strength of the proposed muscle for transfer must be normal or near normal and under the voluntary control of the patient. Typically, the strength of the donor muscle-tendon unit decreases by one grade following transfer; therefore, only donor muscles with 4/5 or 5/5 strength should be used for tendon transfers
The tendon excursion of the donor unit must be sufficient to restore the lost function of the recipient unit. For example, in wrist extension and flexion, there is 33 mm of tendon excursion. Finger extension and flexion have a tendon excursion of 50 mm and 70 mm, respectively. Wrist flexion and extension can add 20-30 mm of excursion through a tenodesis effect
The direction of pull (i.e.vector) of the recipient tendon should be in line with that of the donor muscle and, ideally, the transfer should cross only one joint
A single transferred tendon should perform one intended function
The soft-tissue bed for the transfer must be stable and allow for tendon gliding with pliable, unscarred overlying skin. Transfers must not be placed through heavily scarred soft-tissue planes, which limit excursion.
Preoperatively, the joints controlled by the transferred tendon must have nearly full passive range of motion (ROM). Preoperative occupational hand therapy may be necessary to improve ROM before tendon transfer. In some cases, joint release may be necessary before the transfer is performed
Tendons with in-phase functions should be used preferentially. The synergistic action of the proposed muscle for transfer and the recipient muscle ( e.g., finger flexors acting in concert with wrist extensors and finger extensors with wrist flexors) can facilitate muscle retraining after transfer.

To restore wrist extension, the PT tendon is transferred to the ECRB tendon. The ECRB is chosen over the extensor carpi radialis longus (ECRL) secondary to its more central insertion onto the base of the long metacarpal and balanced radioulnar deviation during wrist extension.^[7] The main advantage of this transfer is that the PT will continue to function as a pronator.

Other tendon transfer options include the following: The FCU to the extensor digitorum communis (EDC) and the FDS of the ring or long finger to the EDC. The advantages and drawbacks of these tendon transfers have been debated. The FCR tends to be easier to harvest and provides adequate excursion and strength without sacrificing wrist flexion and ulnar deviation.^[8] The potential drawback of using the FCU is the sacrifice of coupled wrist flexion and ulnar deviation, which is critical for the dart thrower's motion and the power grip.^[9],[10]

Conclusion

Paralysis or irreparable injury to the radial or median nerve results in considerable impairment of hand function, which directly affects activities of daily living. Tendon transfer can reestablish active movement and enhance function. Maximum benefit after tendon transfer, however, requires a close working relationship among the patient, the physiotherapist, and the physician.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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