x
x

Pitres-Testut Sign (Ulnar)

Exams and Signs

Historical Overview

  • Ulnar nerve palsy is a typically progressive condition that can result in complex and multifaceted disabilities if not managed properly.1,2
  • Several eponymous signs have been describedto assist with the diagnosis and management of ulnar nerve palsy. Although many of these signs are primarily of academic interest, some may be used to indicate the severity of the palsy.1
    • One of these diagnostic tools is the Pitres-Testut sign, which was initially described in 1925. It focuses specifically on abduction of the long finger and precision grasp abilities.1,3

Description

  • The Pitres-Testut sign is a diagnostic test used to determine the extent of ulnar nerve palsy by evaluating a patient’s ability to abduct the long finger—radially and ulnarly—and collectively extend the fingers in a cone.1,3

Pathophysiology

  • The ulnar nerve is the terminal branch of the medial cord of the brachial plexus. It largely consists of nerve fibers from C8 and T1 nerve roots, but may have contributions from C7 or higher.4
  • Most ulnar nerve palsies are the result of trauma in the developed world, while systemic neurologic conditions are more dominant in developing countries. Other possible causes include neuromuscular dysfunction (hereditary sensory-motor neuropathy or poliomyelitis), infection (leprosy), and chronic ulnar nerve compression.2,4
  • With classic low ulnar nerve palsy, there is complete loss of function of the interossei and 2 ulnar lumbricals, resulting in a loss of the primary flexors of the metacarpophalangeal (MP) joints and extensors of the interphalangeal (IP) joints.
    • The extrinsic flexors can compensate for this loss, but the flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) tendons only flex the MP joint once the IP joints have reached maximum flexion.
    • High ulnar nerve palsy adds the loss of the ulnar half of the FDP, which further weakens grip strength and grasp.5

Instructions

  1. Obtain a complete and accurate patient history that includes any associated trauma.
  2. Evaluate the skin and soft tissues for any trophic ulcers.
  3. Have the patient place their hand on a flat surface in the supine position with only the long finger extended.
  4. Ask the patient to abduct the long finger in the radial direction.
  5. Ask the patient to abduct the long finger in the ulnar direction.
  6. Request that the patient extend all fingers and bring them together in the shape of a cone.

Related Signs and Tests1

  • Andre-Thomas’ sign
  • Bouvier’s sign
  • Bunnell’s sign
  • Duchenne’s sign
  • Earlee-Vlastou’s sign
  • Egawa’s sign
  • Froment’s sign
  • Jeanne’s sign
  • Masse’s sign
  • Mumenthaler’s sign
  • Pollock’s sign
  • Sunderland’s sign
  • Wartenberg’s sign

Diagnostic Performance Characteristics

  • If the patient is unable to abduct the long finger, it’s due to atrophy of the intrinsic muscles, which decreases the breadth of the hand, while weakened dorsal interossei muscles prevent radial and ulnar deviation.1
  • Weakened volar interossei muscles prevent the adduction of the digits into a cone shape.1

Additional Information

Definition of Positive Result
  • A positive result occurs when the patient is unable to abduct the long finger in the ulnar or radial direction, or extend the fingers into a cone.
Definition of Negative Result
  • A negative result occurs when the patient is able to abduct the long finger in ulnar and radial directions, and extend the fingers into a cone.
Comments and Pearls
  • A sound understanding of the anatomy of the different muscles and biomechanics of the potential transfers will help to ensure optimal outcomes for ulnar nerve palsy patients.4
  • Ulnar nerve palsy leads to multiple complex deficiencies, and the clinical significance of these vary according to age, relative joint laxity, soft-tissue and skin elasticity, and individual functional demands.4
Diagnoses Associated with Exams and Signs
References
  1. Draeger, RW and Stern, PJ. The inverted pyramid sign and other eponymous signs of ulnar nerve palsy. J Hand Surg Am 2014;39(12):2517-20. PMID: 25239048
  2. Goldfarb, C. Low Ulnar Nerve Palsy. J Am Soc Surg Hand 2003;3(1):14-26.
  3. Pitres A, Testut L. Les Nerfs en Schemas. Paris, France: Doin; 1925.
  4. Gottschalk, HP and Bindra, RR. Late reconstruction of ulnar nerve palsy. Orthop Clin North Am 2012;43(4):495-507.PMID: 23026465
  5. Diaz-Garcia, RJ and Chung, KC. A Comprehensive Guide on Restoring Grasp Using Tendon Transfer Procedures for Ulnar Nerve Palsy. Hand Clin 2016;32(3):361-8. PMID: 27387079
Subscribe to Pitres-Testut Sign (Ulnar)
⇡