Intraoperative immediate strength recovery following lacertus fibrosus release in patients with proximal median nerve compression at the elbow

• Published in: International orthopaedics Vol. 47; no. 11; pp. 2781 - 2786
• Main Authors: Azócar, Camila, Corvalán, Gonzalo, Orellana, Pablo, Cobb, Peter, Liendo, Rodrigo, Román, Javier
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-11-2023
• Subjects: Medicine; Medicine & Public Health; Original Paper; Orthopedics; Compression neuropathy; Lacertus syndrome; Lacertus fibrosus; Hand surgery; Median nerve entrapment
• ISSN: 0341-2695; 1432-5195
• DOI: 10.1007/s00264-023-05888-6

Purpose
In the literature, we find that patients with lacertus syndrome (LS), proximal median nerve compression at the elbow, present subjective improvement of thumb, and index flexion strength after lacertus fibrosus (LF) release. The aim of this study is to objectively evaluate the immediate change in intraoperative flexion strength after LF release.
Method
We retrospectively reviewed prospectively collected data of a cohort of 24 patients with a double crush syndrome of the median nerve with no response to conservative treatment. All patients had surgery with LF and carpal tunnel release (CTR) under wide-awake local anaesthesia and no tourniquet (WALANT) and were evaluated intraoperatively with a dynamometer immediately before and after LF release.
Flexor digitorum profundus
of the second finger (FDP2) and
Flexor pollicis longus
(FPL) were tested in peak strength to failure. The primary outcome was the percentage of change in strength before and after the release in both assessed muscles. CTR was done after evaluating the change in flexor strength.
Results
A percentage of 79.2 women with an average age of 43.3 years. The average strength of FDP2 before LF release was 15.5 pounds (lbs.) (7.0 kg) (SD, 7.2 lbs (3.3 kg)) and 27.1 lbs. (12.2 kg) (SD, 7.1 lbs. (3.2 kg)) after LF release, which corresponds to a 96% (SD, 70%) change in strength (
p
=0.000). For FPL, the average pre-release strength was 17.7 lbs. (8.0kg) (SD, 4.8 lbs. (2.2 kg)) and 27.4 lbs. (12.4 kg) (SD, 5.2 lbs. (2.4 kg)) post-release, this corresponded to a 65% (SD, 38%) change in strength (
p
=0.000).
Conclusions
Peak strength to failure in FDP2 and FPL has an immediate significant recovery after LF surgical release in patients with Lacertus syndrome.
Level of evidence: IV, retrospective study.