The Extensor Pollicis Longus-Loop-Knot (ELK) Procedure for Dynamic Balance of the Paralyzed Thumb Interphalangeal Joint

Abstract

Hyperflexion of the thumb interphalangeal (IP) joint interferes significantly with pinching between the thumb and the index finger in a paralyzed hand. The extensor pollicis longus-loop-knot (ELK) procedure was used successfully in 7 tetraplegic patients to balance the IP joint between strong restored flexor function and lacking or weak antagonism of the thumb extensors. A V-shaped incision was made over the extensor hood at the level of the IP joint, the extensor pollicis longus (EPL) tendon was elevated, a loop was formed, secured by sutures, and then turned proximally onto the EPL tendon itself and fixed on both sides. The operation reliably limited the maximum range of IP flexion at 20 to 30 degrees from neutral. Postoperative problems did not occur. The ELK procedure is easy and quick and secures the optimal setting of IP flexion with limited flexibility, which is advantageous compared with rigid bony arthrodesis. It also avoids certain disadvantages of the commonly used flexor pollicis longus split tenodesis and is therefore a valuable alternative for the correction of Froment's sign due to intrinsic or extrinsic paralysis of the thumb.