Advertisement

HAND

, Volume 8, Issue 1, pp 41–46 | Cite as

Clinical diagnosis and wide-awake surgical treatment of proximal median nerve entrapment at the elbow: a prospective study

  • Elisabet HagertEmail author
Surgery Articles

Abstract

Background

Proximal median nerve entrapment (PMNE, or pronator syndrome) at the elbow has traditionally been considered an elusive and rare diagnosis, as it is seldom detectable using electrophysiological techniques. In this paper, the clinical manifestations, physical diagnosis, surgical technique, and results of surgical treatment of PMNE are presented, with accompanying instructional video.

Patients/Methods

During 2011, 44 patients with PMNE were surgically released and followed prospectively, 22 women/22 men, mean age 48.8 (range 25–66). The patients were equally distributed between right/left hands (23/21) and the dominant hand was treated in 56 % of cases. The diagnosis was based on: (1) weakness in median innervated muscles distal to the lacertus fibrosus; (2) pain upon pressure over the median nerve at the level of the lacertus fibrosus; and (3) positive scratch collapse test. A minimally invasive surgical treatment using only local anesthesia with lidocaine–epinephrine and no tourniquet was used, and direct perioperative return of strength in median innervated muscles was seen in all subjects.

Results

The average preoperative quick DASH was 35.4 (range 6.8–77.2); work DASH, 44.3 (6.25–100); and activity DASH, 61.6 (12.5–100). There were 71.1 % patients who completed the 6-month follow-up, and the average postoperative quick DASH was 12.7 (range 0–43.1), which is a statistically significant reduction (p < 0.0001; Student’s paired t test). Similarly, the work and activity DASH was significantly reduced (p < 0.001) to 12.5 (0–75) and 6.25 (0–50), respectively.

Conclusions

PMNE at the level of the lacertus fibrosus should be called lacertus tunnel syndrome to distinguish it from other levels of median nerve entrapment. It is a clinical diagnosis based on three distinct clinical findings: weakness, pain over point of compression, and positive scratch collapse test. Surgical release in local anesthesia allows for a safe, ambulatory, and cost-efficient procedure with low morbidity.

Keywords

Entrapment Median nerve Pronator syndrome Surgery Wide-awake 

Notes

Conflict of Interest

The authors declare that they have no conflict of interest.

Supplementary material

Video 1

The video shows the scratch collapse test in a patient with right-sided lacertus tunnel syndrome. The patient is asked to sustain external rotation of the shoulders with elbows flexed, while the skin over the area of nerve compression is scratched, eliciting a temporary loss of muscle resistance. The healthy left side is compared to the contralateral side where a lacertus tunnel syndrome is present. (MOV 14518 kb)

Video 2

The video illustrates the preoperative clinical examination of a patient with proximal median nerve entrapment (“lacertus tunnel syndrome”), where the flexor carpi radialis (FCR), flexor pollicis longus (FPL), and flexor digitorum profundus of the index finger (FDP II) are found to be weak, as compared to the healthy arm. The appearance of the arm following infiltration anesthesia, detailed description of the surgical technique and immediate peri-/postoperative return of strength following nerve release is also shown in this instructional video. (MOV 206403 kb)

References

  1. 1.
    Andreisek G, Crook DW, Burg D, Marincek B, Weishaupt D. Peripheral neuropathies of the median, radial, and ulnar nerves: MR imaging features. Radiogr: Rev Publ Radiol Soc N Am, Inc. 2006;26(5):1267–87.Google Scholar
  2. 2.
    Boyes JH. On the shoulders of giants. Philadelphia: J.B. Lippincott; 1976.Google Scholar
  3. 3.
    Bridgeman C, Naidu S, Kothari MJ. Clinical and electrophysiological presentation of pronator syndrome. Electromyogr Clin Neurophysiol. 2007;47(2):89–92.PubMedGoogle Scholar
  4. 4.
    Brown JM, Mokhtee D, Evangelista MS, Mackinnon SE. Scratch collapse test localizes osborne’s band as the point of maximal nerve compression in cubital tunnel syndrome. Hand (N Y). 2010;5(2):141–7.CrossRefGoogle Scholar
  5. 5.
    Chang MH, Lee YC, Hsieh PF. The real role of forearm mixed nerve conduction velocity in the assessment of proximal forearm conduction slowing in carpal tunnel syndrome. J Clin Neurophysiol. 2008;25(6):373–7.PubMedCrossRefGoogle Scholar
  6. 6.
    Cheng CJ, Mackinnon-Patterson B, Beck JL, Mackinnon SE. Scratch collapse test for evaluation of carpal and cubital tunnel syndrome. J Hand Surg Am. 2008;33(9):1518–24.PubMedCrossRefGoogle Scholar
  7. 7.
    Dahlin LB, Lundborg G. The neurone and its response to peripheral nerve compression. J Hand Surg Br. 1990;15(1):5–10.PubMedCrossRefGoogle Scholar
  8. 8.
    Franklin GM, Glass L, Javaher SP, Kearney RN. Work-related proximal median nerve entrapment (PMNE) diagnosis and treatment. In: Industries WSDoLa, ed. Seattle, Washington 2009:1–11Google Scholar
  9. 9.
    Gillenwater J, Cheng J, Mackinnon SE. Evaluation of the scratch collapse test in peroneal nerve compression. Plast Reconstr Surg. 2011;128(4):933–9.PubMedCrossRefGoogle Scholar
  10. 10.
    Hagert CG, Hagert E. Manual muscle testing—a clinical excamination technique for diagnosing focal neuropathies in the upper extremity. In: Slutsky DJ, editor. Upper extremity nerve repair—tips and techniques: a master skills publicatioN. Rosemont: the American Society for Surgery of the Hand; 2008. p. 451–66.Google Scholar
  11. 11.
    Jepsen JR, Laursen LH, Hagert CG, Kreiner S, Larsen AI. Diagnostic accuracy of the neurological upper limb examination II: relation to symptoms of patterns of findings. BMC Neurol. 2006;6:10.PubMedCrossRefGoogle Scholar
  12. 12.
    Jepsen JR, Laursen LH, Kreiner S, Larsen AI. Neurological examination of the upper limb: a study of construct validity. Open Neurol J. 2009;3:54–63.PubMedCrossRefGoogle Scholar
  13. 13.
    Lee AK, Khorsandi M, Nurbhai N, Dang J, Fitzmaurice M, Herron KA. Endoscopically assisted decompression for pronator syndrome. J Hand Surg Am. 2012;37(6):1173–9.PubMedCrossRefGoogle Scholar
  14. 14.
    Mackinnon SE, Novak CB. Compression neuropathies. In: Wolfe SW, Hotchkiss RN, Pederson WC, Kozin S, editors. Green’s operative hand surgery, 6th Edition. Vol 1. 6th ed. Philadelphia: Elsevier Churchill Livingston; 2011. p. 977–1014.CrossRefGoogle Scholar
  15. 15.
    Presciutti S, Rodner CM. Pronator syndrome. J Hand Surg Am. 2011;36(5):907–9. quiz 909.PubMedCrossRefGoogle Scholar
  16. 16.
    Rehak DC. Pronator syndrome. Clin Sports Med. 2001;20(3):531–40.PubMedCrossRefGoogle Scholar
  17. 17.
    Rydevik B, Lundborg G. Permeability of intraneural microvessels and perineurium following acute, graded experimental nerve compression. Scand J Plast Reconstr Surg. 1977;11(3):179–87.PubMedCrossRefGoogle Scholar
  18. 18.
    Seyffarth H. Primary myoses in the M. pronator teres as cause of lesion of the N. medianus (the pronator syndrome). Acta psychiatr Neurol Scand Suppl. 1951;74:251–4.PubMedGoogle Scholar
  19. 19.
    Stal M, Hagert CG, Moritz U. Upper extremity nerve involvement in Swedish female machine milkers. Am J Ind Med. 1998;33(6):551–9.PubMedCrossRefGoogle Scholar
  20. 20.
    Stal M, Hagert CG, Englund JE. Pronator syndrome: a retrospective study of median nerve entrapment at the elbow in female machine milkers. J Agric Saf Heal. 2004;10(4):247–56.Google Scholar
  21. 21.
    Sunderland S. The intraneural topography of the radial, median and ulnar nerves. Brain. 1945;68:243–99.PubMedCrossRefGoogle Scholar
  22. 22.
    Tsai TM, Syed SA. A transverse skin incision approach for decompression of pronator teres syndrome. J Hand Surg Br. 1994;19(1):40–2.PubMedCrossRefGoogle Scholar
  23. 23.
    Zancolli ER, Zancolli 3rd EP, Perrotto CJ. New Mini-invasive decompression for pronator teres syndrome. J Hand Surg Am. 2012;37(8):1706–10.PubMedCrossRefGoogle Scholar

Copyright information

© American Association for Hand Surgery 2013

Authors and Affiliations

  1. 1.Department of Clinical Science and Education, Hand & Foot Surgery CenterKarolinska InstitutetStockholmSweden

Personalised recommendations