That Tendon is the Median Nerve: Perils of a Palmaris Longus Deficient Wrist

2017 ◽  
Vol 22 (02) ◽  
pp. 160-166 ◽  
Author(s):  
Colin Yi-Loong Woon ◽  
Ramadevi Gourineni ◽  
Summer Watkins ◽  
Rhea Richardson ◽  
Prasad Gourineni
Keyword(s):  
Clinical Study ◽  
Median Nerve ◽  
Healthy Subjects ◽  
Imaging Study ◽  
Tendon Graft ◽  
Fiducial Marker ◽  
Distal Forearm ◽  
Careful Scrutiny ◽  
Palmaris Longus ◽  
Antebrachial Fascia

Background: To document the course of the median nerve in the distal forearm in palmaris longus (PL) deficient forearms and elucidate features that help distinguish it from the PL. Methods: In the cadaveric study, 56 cadaveric forearms were dissected and the location and course of the median nerve were documented. In the clinical study, 20 healthy subjects with absent PL were examined with provocative tests to elucidate the PL (Schaeffer’s test and Thompson’s test), and modified Durkan’s and Phalen’s tests. In the imaging study, one subject with a clearly visible and palpable median nerve was further evaluated with MRI with a superficial fiducial marker. Results: Cadaveric dissection revealed that the median nerve was deep to the antebrachial fascia and superficial to the FDS tendons in the distal forearm. In 9 specimens without a PL, the median nerve was the most superficial structure deep and lay draped over the FDS tendons. In the clinical study, PL absence was bilateral in 4 subjects and unilateral in 16. The nerve was visible and palpable in 4 forearms and palpable but not visible in 20 forearms. In all 24 forearms, the nerve was palpable as a lax, mobile, cord-like structure that could be rolled over the taut FDS tendons. Tinel’s and Durkan’s signs were positive in 11 subjects. In the imaging study, MRI confirmed that the palpable structure was the median nerve. Conclusions: Unlike the PL, the nerve is non-contractile and remains flaccid on provocative testing. It is usually palpable and may also be visible in thin forearms. Careful scrutiny may reveal it to be distinct from, and draped over underlying FDS tendons. These findings may help avoid inadvertent median nerve harvest in place of a PL tendon graft.

scholarly journals Iatrogenic Injury to the Median Nerve During Palmaris Longus Harvest

Hand ◽  
2016 ◽  
Vol 12 (1) ◽  
pp. NP6-NP9 ◽  
Author(s):  
Joshua Choo ◽  
Bradon J. Wilhelmi ◽  
Morton L. Kasdan
Keyword(s):  
Median Nerve ◽  
Tendon Graft ◽  
Iatrogenic Injury ◽  
True Incidence ◽  
Longus Tendon ◽  
Palmaris Longus ◽  
Palmaris Longus Tendon

Background: A rare and disastrous complication of harvesting a tendon graft is the misidentification of the median nerve for the palmaris longus. Methods: The authors report a referred case in which the median nerve was harvested as a free tendon graft. Results: Few reports of this complication are found in the literature despite the frequency of palmaris longus tendon grafting and the proximity of the palmaris tendon to the median nerve. Given the obvious medicolegal implications, the true incidence of this complication is difficult to assess. Discussion: Safe harvesting of the palmaris longus mandates a thorough understanding of the relevant anatomy, in particular the proper differentiation between nerve and tendon and recognition of when the palmaris longus tendon is absent. Techniques to facilitate proper identification of the palmaris longus are outlined.

Median Nerve as Free Tendon Graft

1987 ◽  
Vol 12 (2) ◽  
pp. 187-188
Author(s):  
M. VASTAMÄKI
Keyword(s):  
Median Nerve ◽  
Flexor Tendon ◽  
Extensor Tendon ◽  
Tendon Graft ◽  
Tendon Injury ◽  
Longus Tendon ◽  
Flexor Tendon Injury ◽  
Palmaris Longus ◽  
Palmaris Longus Tendon ◽  
Sural Nerve Graft

Four patients are described, all of whom bad tendon injuries in which the median nerve was used as a free tendon graft. Three cases involved the repair of a flexor tendon injury, and one the repair of an extensor tendon. In all cases, reconstruction of the median nerve was performed with a free sural nerve graft. The difficulty was that the palmaris longus tendon was missing in all cases. The importance of preoperative clinical testing for the presence of the palmaris longus tendon is emphasized.

The angular course of the median nerve in the distal forearm and its anatomical importance in preventing nerve injury in a modern era of carpal tunnel release

2017 ◽  
Vol 126 (3) ◽  
pp. 979-984 ◽  
Author(s):  
Russell Payne ◽  
Zeinab Nasralah ◽  
Emily Sieg ◽  
Elias B. Rizk ◽  
Michael Glantz ◽  
...  
Keyword(s):  
Median Nerve ◽  
Carpal Tunnel ◽  
Carpal Tunnel Release ◽  
Mean Value ◽  
Distal Forearm ◽  
Flexor Digitorum Superficialis ◽  
Palmaris Longus ◽  
The Mean ◽  
Flexor Digitorum ◽  
Modern Era

OBJECTIVE A thorough understanding of anatomy is critical for successful carpal tunnel release. Several texts depict the median nerve (MN) as taking a course parallel to the long axis of the forearm (LAF). The authors report on their attempt to formally assess the course of the MN as it travels to the carpal tunnel in the distal wrist and discuss its potential clinical significance. METHODS The width of the wrist, the distance from the radial wrist to the MN, and the distance from the distal volar wrist crease to the point where the MN emerges between the flexor carpi radialis (FCR) tendon and the flexor digitorum superficialis (FDS) tendons were recorded during cadaveric dissection of 76 wrist specimens. The presence or absence of palmaris longus was documented. Finally, the angles between the MN and FCR tendon and between the MN and the LAF were measured using ImageJ. RESULTS The relative position of the MN at the distal wrist crease, as determined by the ratio of the distance from the MN to the radial wrist divided by wrist width, revealed a mean value of 0.48, indicating that the nerve was usually located just radial to midline. The mean distance between the distal wrist crease and the MN's emergence was 34.6 mm. The mean angle between the MN and the FCR tendon was 14.1°. The angle between the MN and the LAF had a mean value of 8.8° (range 0.0°–32.2°). The nerve was parallel to the LAF in only 10.7% of the studied wrists. Palmaris longus was absent in 14 (18.4%) of the 76 wrists. CONCLUSIONS The MN takes an angular approach to the carpal tunnel in the distal wrist in the vast majority of cases. This newly described finding will be useful to both clinicians and anatomists.

scholarly journals The Prevalence and Patterns of Palmaris Longus Muscle Absence in an Iranian Population

2019 ◽  
Vol 9 (4) ◽  
pp. 279-282
Author(s):  
Mehdi Forouzesh ◽  
Abdolrazagh Barzegar ◽  
Fardin Fallah
Keyword(s):  
Gender Difference ◽  
Clinical Importance ◽  
Tendon Graft ◽  
Iranian Population ◽  
Geographical Variability ◽  
Palmaris Longus ◽  
Longus Muscle ◽  
Palmaris Longus Muscle ◽  
And Gender ◽  
Gender Specific

Palmaris Longus (PL) is a muscle of the forearm, i.e., not functionally necessary and does not exist in all people. It is a choice for tendon graft and investigating its prevalence is of clinical importance. During April-October 2009, 102 cadavers (78 males, 24 females) were bilaterally necropsied for PL exploration in Zanjan City, Iran. PL Absence (PLA) was observed in 37 (36.3%) cases (28 males, 9 females). PLA prevalence was similar in men (36%) and women (37.5%). Of PLA cases, 19 (51%) were unilateral (14 males, 5 females), and 18 (49%) were bilateral (14 males, 4 females). In conclusion, PLA prevalence of 36.3% in our population was similar to other studies conducted in Iran. We found no gender difference in PLA prevalence and its patterns. Due to geographical variability in PLA rate, future regional and national studies with more magnificent sample sizes are recommended to determine the prevalence and gender-specific patterns of PLA.

scholarly journals Bifid Median Nerve in the Bulgarian Population: An Anatomical and Clinical Study

2015 ◽  
Vol 2015 ◽  
pp. 1-4
Author(s):  
Georgi P. Georgiev ◽  
Svetoslav A. Slavchev ◽  
Iva N. Dimitrova ◽  
Boycho Landzhov
Keyword(s):  
Clinical Study ◽  
Median Nerve ◽  
Carpal Tunnel ◽  
Anatomical Variation ◽  
Clinical Implications ◽  
Upper Limbs ◽  
Anatomical Variant ◽  
Human Cadavers ◽  
Tunnel Syndrome ◽  
Bulgarian Population

High division of the median nerve proximal to the carpal tunnel, also known as a bifid median nerve, is a rare anatomical variant with an incidence between 1 and 3%. In order to study the incidence of this anatomical variation in the Bulgarian population, we examined the upper limbs of 51 formol-carbol fixed human cadavers and also 154 upper limbs undergoing carpal tunnel decompression. We detected one case of bifid median nerve during anatomical dissections and two cases in patients with carpal tunnel syndrome. In one of the clinical cases, the anatomical variation was detected preoperatively by MRI. We discuss different variations of this nerve and emphasize their potential clinical implications.

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