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Lumbrical Muscles Neural Branching Patterns: A Cadaveric Study With Potential Clinical Implications.Hand (New York, N.Y.) Sep 2022Lumbrical muscles originate in the palm from the 4 tendons of the flexor digitorum profundus and course distally along the radial side of the corresponding...
BACKGROUND
Lumbrical muscles originate in the palm from the 4 tendons of the flexor digitorum profundus and course distally along the radial side of the corresponding metacarpophalangeal joints, in front of the deep transverse metacarpal ligament. The first and second lumbrical muscles are typically innervated by the median nerve, and third and fourth by the ulnar nerve. A plethora of lumbrical muscle variants has been described, ranging from muscles' absence to reduction in their number or presence of accessory slips. The current cadaveric study highlights typical and variable neural supply of lumbrical muscles.
MATERIALS
Eight (3 right and 5 left) fresh frozen cadaveric hands of 3 males and 5 females of unknown age were dissected. From the palmar wrist crease, the median and ulnar nerve followed distally to their terminal branches. The ulnar nerve deep branch was dissected and lumbrical muscle innervation patterns were noted.
RESULTS
The frequency of typical innervations of lumbrical muscles is confirmed. The second lumbrical nerve had a double composition from both the median and ulnar nerves, in 12.5% of the hands. The thickest branch (1.38 mm) originated from the ulnar nerve and supplied the third lumbrical muscle, and the thinnest one (0.67 mm) from the ulnar nerve and supplied the fourth lumbrical muscle. In 54.5%, lumbrical nerve bifurcation was identified.
CONCLUSION
The complex innervation pattern and the peculiar anatomy of branching to different thirds of the muscle bellies are pointed out. These findings are important in dealing with complex and deep injuries in the palmar region, including transmetacarpal amputations.
Topics: Cadaver; Female; Hand; Humans; Male; Median Nerve; Muscle, Skeletal; Ulnar Nerve
PubMed: 33349041
DOI: 10.1177/1558944720963881 -
Measurement of Median Nerve Strain and Applied Pressure for the Diagnosis of Carpal Tunnel Syndrome.Ultrasound in Medicine & Biology Jun 2017The objective of this study was to evaluate the diagnostic utility of strain and applied-pressure measurements of the median nerve in carpal tunnel syndrome (CTS)....
The objective of this study was to evaluate the diagnostic utility of strain and applied-pressure measurements of the median nerve in carpal tunnel syndrome (CTS). Thirty-five wrists of 23 idiopathic CTS patients and 30 wrists of 15 normal patients were examined. Median nerve strain, pressure to the skin and the pressure/strain ratio were measured at the proximal carpal tunnel level. Parameters were compared between CTS patients and controls. The areas under the receiver operating characteristic curves (AUCs) were compared for the parameters. Median nerve strain was significantly lower in the patients than in the controls (p < 0.01). Pressure and pressure/strain ratio were significantly higher in the patients than in the controls (p < 0.05: pressure, p < 0.01: ratio). The AUCs were 0.926, 0.681 and 0.937 for strain, pressure and pressure/strain ratio, respectively. Pressure/strain ratio is useful for evaluating the condition of the median nerve with respect to the hardness of the surrounding structures in CTS.
Topics: Adult; Aged; Aged, 80 and over; Carpal Tunnel Syndrome; Compressive Strength; Elastic Modulus; Elasticity Imaging Techniques; Female; Humans; Image Interpretation, Computer-Assisted; Male; Manometry; Median Nerve; Middle Aged; Pressure; Reproducibility of Results; Sensitivity and Specificity; Stress, Mechanical; Tensile Strength
PubMed: 28395966
DOI: 10.1016/j.ultrasmedbio.2017.02.018 -
Folia Medica Cracoviensia 2019The musculocutaneous nerve (C5-C7) is a terminal branch of the lateral cord of the brachial plexus and provides motor innervation to the anterior compartment of arm...
The musculocutaneous nerve (C5-C7) is a terminal branch of the lateral cord of the brachial plexus and provides motor innervation to the anterior compartment of arm muscles. Both the musculocutaneous and median nerve may show numerous anatomical variations. Keeping in mind possible aberrations in the course of the upper limb nerves may increase the safety and success rate of surgical procedures. The presented report is a detailed anatomical study of the fusion between the median and musculocutaneous nerve, supplemented by intraneural fascicular dissection. In the presented case, the musculocutaneous nerve was not found in its typical location in the axillary cavity and upper arm during the preliminary assessment. However, a careful intraneural fascicular dissection revealed that musculocutaneous nerve was fused with the median nerve and with its lateral root; Those nerves were surrounded by a common epineurium, however they were separable. The muscular branch to the biceps brachii muscle arose from the trunk (fascicular bundle) dissected out from the median nerve and corresponding to the musculocutaneous nerve. Such variation may be of utmost clinical importance, especially during reconstructions of the brachial plexus or its branches.
Topics: Humans; Male; Median Nerve; Muscle, Skeletal; Musculocutaneous Nerve
PubMed: 31891359
DOI: 10.24425/fmc.2019.131135 -
Hand (New York, N.Y.) Dec 2016Nerve transfers have resulted in increased interest in the microanatomy of peripheral nerves. Herein, we expand our understanding of the internal anatomy of the digital...
Nerve transfers have resulted in increased interest in the microanatomy of peripheral nerves. Herein, we expand our understanding of the internal anatomy of the digital nerve to the ulnar index and long fingers, the radial long and ring fingers, and the nerves to the second and third web spaces. The median nerve was dissected from the digital nerves to the antecubital fossa in 14 fresh upper extremities. The distance of proximal internal neurolysis of the fascicles to the second and third web space and proper digital nerves was measured relative to the radial styloid. Plexi encountered during proximal lysis were noted. Digital nerves to the ulnar index and radial long fingers were lysed 2.4 ± 0.5 cm (mean ± SD), and digital nerves to the ulnar long and the radial ring fingers were lysed 3.0 ± 0.6 cm distal to the radial styloid. Fascicles to the third web space were lysed to the takeoff of the anterior interosseous nerve, 21.1 ± 1.4 cm. Plexus groupings were encountered at 4.5 ± 1.6 cm, 8.3 ± 1.2, cm and 16.1 ± 1.9 cm proximal to radial styloid. The fascicles to the second web space were lysed to 5.0 ± 1.2 cm proximal to radial styloid where a plexus grouping was encountered. Another plexus group was found at 3.3 ± 1.3 cm. We demonstrate that extended internal neurolysis of second web space, along with the digital nerves, is technically and clinically feasible. This technique can be used to treat mixed median nerve injury in the hand and wrist.
Topics: Cadaver; Fingers; Forearm; Hand; Humans; Median Nerve; Nerve Block; Ulnar Nerve; Wrist
PubMed: 28149207
DOI: 10.1177/1558944716643290 -
Clinical Rheumatology Dec 2021
Topics: Carpal Tunnel Syndrome; Humans; Median Nerve; Ultrasonography
PubMed: 34247290
DOI: 10.1007/s10067-021-05851-z -
Clinical Orthopaedics and Related... Nov 2015The median and radial nerves are at risk of iatrogenic injury when performing arthroscopic arthrolysis with anterior capsulectomy. Although prior anatomic studies have...
BACKGROUND
The median and radial nerves are at risk of iatrogenic injury when performing arthroscopic arthrolysis with anterior capsulectomy. Although prior anatomic studies have identified the position of these nerves, little is known about how elbow positioning and joint insufflation might influence nerve locations.
QUESTIONS/PURPOSES
In a cadaver model, we sought to determine whether (1) the locations of the median and radial nerves change with variation of elbow positioning; and whether (2) flexion and joint insufflation increase the distance of the median and radial nerves to osseous landmarks after correcting for differences in size of the cadaveric specimens.
METHODS
The median and radial nerves were marked with a radiopaque thread in 11 fresh-frozen elbow specimens. Three-dimensional radiographic scans were performed in extension, in 90° flexion, and after joint insufflations in neutral rotation, pronation, and supination. Trochlear and capitellar widths were analyzed. The distances of the median nerve to the medial and anterior edge of the trochlea and to the coronoid were measured. The distances of the radial nerve to the lateral and anterior edge of the capitulum and to the anterior edge of the radial head were measured. We analyzed the mediolateral nerve locations as a percentage function of the trochlear and capitellar widths to control for differences regarding the size of the specimens.
RESULTS
The mean distance of the radial nerve to the lateral edge of the capitulum as a percentage function of the capitellar width increased from 68% ± 17% in extension to 91% ± 23% in flexion (mean difference = 23%; 95% confidence interval [CI], 5%-41%; p = 0.01). With the numbers available, no such difference was observed regarding the location of the median nerve in relation to the medial border of the trochlea (mean difference = 5%; 95% CI, -13% to 22%; p = 0.309). Flexion and joint insufflation increased the distance of the nerves to osseous landmarks. The mean distance of the median nerve to the coronoid tip was 5.4 ± 1.3 mm in extension, 9.1 ± 2.3 mm in flexion (mean difference = 3.7 mm; 95% CI, 2.04-5.36 mm; p < 0.001), and 12.6 ± 3.6 mm in flexion and insufflation (mean difference = 3.5 mm; 95% CI, 0.81-6.19 mm; p = 0.008). The mean distance of the radial nerve to the anterior edge of the radial head increased from 4.7 ± 1.8 mm in extension to 7.7 ± 2.7 mm in flexion (mean difference = 3.0 mm; 95% CI, 0.96-5.04 mm; p = 0.005) and to 11.9 ± 3.0 mm in flexion with additional joint insufflation (mean difference = 4.2 mm; 95% CI, 1.66-6.74 mm; p = 0.002).
CONCLUSIONS
The radial nerve shifts medially during flexion from the lateral to the medial border of the inner third of the capitulum. The median nerve is located at the medial quarter of the joint. The distance of the median and radial nerves to osseous landmarks doubles from extension to 90° flexion and triples after joint insufflation.
CLINICAL RELEVANCE
Elbow arthroscopy with anterior capsulectomy should be performed cautiously at the medial aspect of the joint to avoid median nerve lesions. Performing arthroscopic anterior capsulectomy in flexion at the lateral aspect of the joint and in slight extension at the medial edge of the capitulum could enhance safety of this procedure.
Topics: Aged; Aged, 80 and over; Anatomic Landmarks; Arthroscopy; Biomechanical Phenomena; Cadaver; Elbow Joint; Female; Humans; Insufflation; Male; Median Nerve; Patient Positioning; Peripheral Nerve Injuries; Radial Nerve; Radiography; Range of Motion, Articular
PubMed: 26152782
DOI: 10.1007/s11999-015-4442-3 -
Orphanet Journal of Rare Diseases Sep 2021Mucopolysaccharidosis consists of a group of diseases caused by the deficiency of lysosomal enzymes, which may lead to the compression of the median nerve in the carpal...
BACKGROUND
Mucopolysaccharidosis consists of a group of diseases caused by the deficiency of lysosomal enzymes, which may lead to the compression of the median nerve in the carpal tunnel due to the accumulation of glycosaminoglycan, resulting in the hand disability. The study purpose is to present functional results of carpal tunnel release in mucopolysaccharidosis patients. Patients were selected from an enzyme replacement group in the Department of Pediatric Neurology. The legal guardians of the patients were informed about the likely functional change of the hands induced by compression of the median nerve. Clinical evaluation was performed in those patients who received their legal guardians' consent to participate and was included inspection, assessment of functional level, wrinkle test and the digital pinch function to manipulate small and large objects. Ultrasound and electromyography were performed to confirm the clinical median nerve compression. Bilateral extended opening technique was performed to access the carpal tunnel and analyze the anatomic findings of the median nerve and the flexed tendons of the fingers. After the surgical release of the carpal tunnel, the clinical evaluation was repeated. Subjective observations of the legal guardians were also considered.
RESULTS
Seven patients underwent bilateral surgical opening of the carpal tunnel; six boys, mean age of 9.5 (5 to 13), five of them presenting Type II mucopolysaccharidosis, 1 Type I and 1 Type VI. The average follow-up was 12 months (10-13 months). The functional results observed included the improvement in the handling of small and large objects in all children who underwent decompression of the median nerve. The comparison between the pre-operative and post-operative functional levels revealed that 2 patients evolved from Level II to IV, 3 from Level III to IV, 1 from Level IV to V and 1 patient remained in Level III. Tenosynovitis around the flexor tendons and severe compression of the median nerve in the fourteen carpal tunnels were observed during the surgical procedure. In 6 wrists, partial tenosynovitis was performed.
CONCLUSIONS
Despite the improvement in the overall function of the children' hands, we cannot conclude that only surgery was responsible for the benefit. Better designed studies are required.
Topics: Carpal Tunnel Syndrome; Child; Humans; Male; Median Nerve; Mucopolysaccharidoses; Tendons; Ultrasonography
PubMed: 34503540
DOI: 10.1186/s13023-021-01982-3 -
Journal of Orthopaedic Surgery (Hong... 2017We aimed to compare the movement of the median nerve within the carpal tunnel during wrist and finger motions between before and after carpal tunnel release (CTR) using...
PURPOSE
We aimed to compare the movement of the median nerve within the carpal tunnel during wrist and finger motions between before and after carpal tunnel release (CTR) using transverse ultrasound in carpal tunnel syndrome (CTS) patients and to evaluate the biomechanical efficacy of CTR for CTS.
METHODS
Twenty-four patients with CTS were examined by transverse ultrasound. The location of the median nerve within the carpal tunnel was examined quantitatively as a coordinate at varied wrist positions with finger extension and flexion, respectively, before and after CTR.
RESULTS
We found that the median nerve moved statistically significantly more palmarly after CTR than before at all wrist positions during finger motion. The average median nerve displacement toward the palmar side at the palmar flexion position in finger flexion was the greatest among all positions. Additionally, the displacement amounts of the median nerve during finger motion at all wrist positions were statistically significantly smaller after CTR than before.
CONCLUSIONS
The current study demonstrated the movement patterns of the median nerve in the carpal tunnel during wrist and finger motions compared before and after CTR using transverse ultrasound in CTS patients. The findings suggested that as the median nerve shifted greatly palmarly away from the tendons after CTR, the nerve avoids compression or shearing stress from the tendons. This ultrasound information could offer further understanding of the pathomechanics of CTS and provide a more accurate diagnosis of CTS and better treatment by CTR.
Topics: Adult; Carpal Tunnel Syndrome; Female; Fingers; Humans; Male; Median Nerve; Middle Aged; Movement; Range of Motion, Articular; Stress, Mechanical; Tendons; Ultrasonography; Wrist Joint
PubMed: 28920545
DOI: 10.1177/2309499017730422 -
Hand (New York, N.Y.) May 2022The aims of this study were 2-fold: (1) to assess the morphological change of the median nerve in patients with carpal tunnel syndrome (CTS) preoperatively and at 6 and...
Relationship Between Morphological Change of Median Nerve and Clinical Outcome Before and After Open Carpal Tunnel Release: Ultrasonographic 1-Year Follow-up After Operation.
The aims of this study were 2-fold: (1) to assess the morphological change of the median nerve in patients with carpal tunnel syndrome (CTS) preoperatively and at 6 and 12 months postoperatively; and (2) to analyze correlation between the changes in ultrasonographic findings and the changes in clinical findings after surgical decompression. Of the 28 patients with CTS, 34 wrists were treated with open carpal tunnel release. We evaluated them using the Boston questionnaire, Japanese Society for Surgery of the Hand Version of the Quick Disability of the Arm, Shoulder, and Hand questionnaire, nerve conduction study (NCS), and ultrasound preoperatively and at 6 and 12 months postoperatively. We measured the cross-sectional area (CSA) of the median nerve at the level of the proximal inlet of the carpal tunnel (CSAc) and more proximally at the level of the distal radioulnar joint (CSAd). Paired tests and repeated measures analysis of variance of ranks were used to identify changes over time. The Spearman correlation coefficient by rank test was used for the analysis of the relation between the amount of change of CSA and the patient-rated questionnaire score and NCS findings. Findings for CSAc, CSAd, and NCS and patient-rated outcomes at 6 and 12 months postoperatively were significantly lower than their preoperative values. However, no significant correlation was found between the postoperative changes in CSAc, CSAd, and clinical variables obtained preoperatively and postoperatively. Evaluation of sonographic imaging might not be helpful for assessing clinical conditions in patients with CTS after surgical decompression.
Topics: Carpal Tunnel Syndrome; Follow-Up Studies; Humans; Median Nerve; Ultrasonography; Wrist
PubMed: 32643958
DOI: 10.1177/1558944720937367 -
Journal of Clinical Ultrasound : JCU Mar 2023We aim to evaluate the shear wave velocity (SWV) of the thenar muscle as an adjunct diagnostic tool for carpal tunnel syndrome (CTS).
PURPOSE
We aim to evaluate the shear wave velocity (SWV) of the thenar muscle as an adjunct diagnostic tool for carpal tunnel syndrome (CTS).
METHODS
Ninety-two wrists with CTS and 30 control wrists without CTS underwent ultrasonographic evaluation of thenar muscle and median nerve including shear-wave elastography. Cross sectional area (CSA) of medial nerve and SWV of thenar muscle and median nerve were evaluated. CTS patients were assessed for Boston CTS, Padua CTS, modified Hirani grading scores, and nerve conduction study (NCS). SWVs, CSA, and NCS parameters were compared between two groups.
RESULTS
The SWVs of thenar muscle and median nerve (p < 0.001, respectively), and CSA of median nerve (p < 0.001) were more significantly greater in patients with CTS than in controls. The SWV of median nerve was moderately correlated with CSA of median nerve (r = 0.35, p < 0.001) and modified Hirani CTS score (r = 0.35, p < 0.001). The SWV of thenar muscle was inversely correlated with modified Hirani CTS score (r = -0.21, p = 0.04).
CONCLUSION
The SWV of thenar muscle and median nerve of CTS were significantly increased compared to that of control, and significantly negatively correlated with NCS parameters (modified Hirani CTS score). SWVs may be used as an adjunct diagnostic tool for CTS.
Topics: Humans; Carpal Tunnel Syndrome; Elasticity Imaging Techniques; Ultrasonography; Neural Conduction; Median Nerve; Muscle, Skeletal
PubMed: 36201602
DOI: 10.1002/jcu.23359