Mateusz Gładysz FESSH prep

FESSH prep Compressive neuropathies median nerve

Pronator syndrome

Last reviewed v1.0

FESSH-003Compressive neuropathies●●○ intermediate

Regarding pronator syndrome (compressive neuropathy of the median nerve in the proximal forearm):

  1. 1.Pronator syndrome is typically characterised by nocturnal symptoms similar to carpal tunnel syndrome.

  2. 2.Resisted forearm pronation may reproduce symptoms.

  3. 3.Electrodiagnostic studies are highly reliable for diagnosing pronator syndrome.

  4. 4.The median nerve may be compressed at multiple sites in the proximal forearm, including the ligament of Struthers (when a supracondylar process is present), the lacertus fibrosus, the two heads of pronator teres, and the proximal arch of flexor digitorum superficialis.

  5. 5.Surgical decompression is indicated after failure of an adequate trial of conservative management, typically 3 to 6 months.

FESSH marking: +1 per correct statement, 0 for blank, −1 for incorrect. Click the same TRUE/FALSE button twice to clear it.

Question ID
FESSH-003
First published
Last reviewed
Version
v1.0
Answer key and explanations — open after answering

  1. 1. Pronator syndrome is typically characterised by nocturnal symptoms similar to carpal tunnel syndrome.

    False

    Nocturnal paraesthesia is a hallmark of carpal tunnel syndrome but is characteristically absent in pronator syndrome. Hartz et al., in their series of 39 patients, documented forearm aching, weakness and digit numbness aggravated by cyclic forearm activity rather than nocturnal awakening. The absence of nocturnal symptoms is one of the principal clinical clues distinguishing the two conditions.

    • Hartz CR, Linscheid RL, Gramse RR, Daube JR. The pronator teres syndrome: compressive neuropathy of the median nerve. J Bone Joint Surg Am. 1981;63(6):885-890. PMID 7240329
    • Lee MJ, LaStayo PC. Pronator syndrome and other nerve compressions that mimic carpal tunnel syndrome. J Orthop Sports Phys Ther. 2004;34(10):601-9. PMID 15552706

  2. 2. Resisted forearm pronation may reproduce symptoms.

    True

    In the Hartz et al. series, the distinctive physical sign was tenderness over the proximal pronator teres aggravated by resisted forearm pronation with the elbow extended, by resisted elbow flexion (loading the lacertus fibrosus), and occasionally by resisted contraction of the flexor digitorum superficialis to the long finger (loading the FDS arch). Resisted pronation is a key pronator-teres-localising provocative test.

    • Hartz CR, Linscheid RL, Gramse RR, Daube JR. The pronator teres syndrome: compressive neuropathy of the median nerve. J Bone Joint Surg Am. 1981;63(6):885-890. PMID 7240329

  3. 3. Electrodiagnostic studies are highly reliable for diagnosing pronator syndrome.

    False

    Electrodiagnostic studies in pronator syndrome are frequently normal or non-localising. In the Hartz series, electrophysiological abnormalities were demonstrated in only a minority and localisation of the lesion was rarely possible. Olehnik et al. confirmed this in a surgical series of 36 patients (39 limbs) in which elbow-to-wrist median nerve conduction studies were obtained in 37 limbs and abnormal in only 12 — approximately one-third. The diagnosis is therefore primarily clinical.

    • Olehnik WK, Manske PR, Szerzinski J. Median nerve compression in the proximal forearm. J Hand Surg Am. 1994;19(1):121-126. PMID 8169356
    • Hartz CR, Linscheid RL, Gramse RR, Daube JR. The pronator teres syndrome: compressive neuropathy of the median nerve. J Bone Joint Surg Am. 1981;63(6):885-890. PMID 7240329

  4. 4. The median nerve may be compressed at multiple sites in the proximal forearm, including the ligament of Struthers (when a supracondylar process is present), the lacertus fibrosus, the two heads of pronator teres, and the proximal arch of flexor digitorum superficialis.

    True

    Johnson, Spinner and Shrewsbury defined the four classical sites of median nerve compression in the proximal forearm — the ligament of Struthers (when a supracondylar process is present), the lacertus fibrosus (bicipital aponeurosis), the two heads of the pronator teres, and the proximal fibrous arch of FDS. In their 71-case, 20-year series with 51 surgical cases, multiple compressive structures were frequently encountered intra-operatively. This four-site framework remains the canonical anatomic description in modern reviews.

    • Johnson RK, Spinner M, Shrewsbury MM. Median nerve entrapment syndrome in the proximal forearm. J Hand Surg Am. 1979;4(1):48-51. PMID 759503
    • Pećina MM, Krmpotić-Nemanić J, Markiewitz AD. Tunnel Syndromes: Peripheral Nerve Compression Syndromes. 3rd ed.. Boca Raton, FL: CRC Press; 2001. ISBN 9780849309519

  5. 5. Surgical decompression is indicated after failure of an adequate trial of conservative management, typically 3 to 6 months.

    True

    A trial of conservative management — activity modification, splinting, NSAIDs, and treatment of any associated overuse — is recommended as first-line therapy. Surgical decompression of all four potential sites is indicated when symptoms persist despite an adequate non-operative trial, typically 3 to 6 months. Olehnik et al. reviewed surgical outcomes in 36 patients undergoing decompression after failure of conservative therapy, with symptomatic relief in the majority of cases.

    • Olehnik WK, Manske PR, Szerzinski J. Median nerve compression in the proximal forearm. J Hand Surg Am. 1994;19(1):121-126. PMID 8169356