Objective: Giant cell tumor of tendon sheath is a rare cause of ulnar tunnel syndrome. We present a case of a 37-year-old woman who presented with decreased sensation and weakness of grip of the right hand. Magnetic resonance imaging indicated the presence of a mass in the hypothenar eminence and showed that the mass was associated with the flexor carpi ulnaris tendon and displacing the ulnar neurovascular bundle. A differential diagnosis included desmoid tumor and sarcoma. Methods: Surgical examination showed a mass that was associated with the flexor carpi ulnaris tendon and flexor retinaculum located in the distal portion of Guyon's canal and intertwined with the ulnar nerve and displacing the ulnar artery. The mass was removed and Guyon's canal was released. Results: Histological examination indicated a diagnosis of giant cell tumor of tendon sheath (GCTTS). Postoperatively, the patient had fully restored sensory and motor function of the right hand. Conclusions: Although GCTTS is the most common solid, soft-tissue lesion of the hand, it is rarely diagnosed properly preoperatively. Therefore, it is imperative to always include GCTTS in the differential diagnosis of any mass of the hand.
In recent years, distal nerve transfers have become a valid tool for nerve reconstruction. Though grafts remain the gold standard for proximal median nerve injuries, a new distal transfer of flexor carpi ulnaris branches of the ulnar nerve to selectively restore anterior interosseous nerve function, concomitant with median nerve graft repair, could enhance outcomes. The objective of this paper is to anatomically analyze a technique to selectively reinnervate the thumb and index flexors.
Both the median and ulnar nerves were dissected in 10 cadavers. First and second branches to the flexor carpi ulnaris (FCU) were measured for length at its emergence from the ulnar nerve, and for width. The emergence of the AIN, just proximal to the arch of the flexor digitorum superficialis, was dissected, and the distance measured from this point to its motor entry at the long flexor pollicis and its branch to the long index flexor. A tensionless repair was performed between one FCU branch and the AIN.
The mean AIN length was 32.3±8.20 mm and width 2.4±0.49 mm. The first branch from the ulnar nerve to the FCU measured 20.8±2.04 mm and 1.52±0.44 mm, while the second, more distal branch measured 24.3±6.71 and 1.9±0.17 mm, respectively. In all dissections, it was possible to contact both the proximal and distal branches of the ulnar nerve to the FCU with the distal stump of the divided AIN, with no tension or need for interposed nerve grafts.
Though proximal reconstruction remains the gold standard, new distal nerve transfer techniques may improve outcomes.
Axon donor; distal nerve transfer; flexor carpi ulnaris; median nerve injury; nerve reconstruction
During blocks of the ulnar nerve induced by inflating a sphygmomanometer cuff round the arm, the strengths of the movements of ulnar deviation of the individual fingers and adduction of the thumb were measured by means of a pressure transducer. No statistically significant differences were found between the times at which failure of these movements occurred, and there was no evidence of the occurrence of a centripetal motor paralysis within the territory of the ulnar nerve in the hand. However, the flexor carpi ulnaris did not become paralysed until significantly later than the small muscles of the hand. The results do not support the idea that long motor fibres are more susceptible to asphyxia than short ones, at least when the difference in length is 4 cm or less. Such a theory could certainly explain the relative immunity of the flexor carpi ulnaris, but other explanations for this finding may be available.
Ulnar nerve is a branch of the brachial plexus. In the front of the forearm, normally near the wrist joint, it gives a dorsal cutaneous branch which supplies the skin of the dorsum of the hand.
The present case reports a very rare finding, the dorsal branch of the ulnar nerve along with the main nerve trunk originated between the two heads of the flexor carpi ulnaris muscle, after descending along the medial border of the forearm extensor surface, on the dorsal aspect of the wrist it is divided into three branches, one medial and two lateral. The medial most division received a communicating branch from the superficial ramus of the ulnar nerve and continued as the medial proper digital nerve of the little finger. The lateral two divisions became cutaneous on the medial half of the dorsum of the hand along the medial three digits i.e. radial and ulnar side of little, ring and middle finger.
The site, extent of injury, variations and the delay in the treatment, significantly influences the outcome of ulnar nerve repair. Thus, an adequate knowledge of all possible variations in the ulnar nerve may be important for clinicians and may help to explain uncommon symptoms.
Blind intramuscular injection might cause severe neurovascular injury if it would be performed with insufficient knowledge of anatomy around the injection area. We report a case of pseudo-anterior interosseous syndrome caused by multiple intramuscular steroid injections around the antecubital area. The patient had weakness of the 1st to 3rd digits flexion with typical OK sign. Muscle atrophy was noted on the proximal medial forearm, and sensation was intact. The electrophysiologic studies showed anterior interosseous nerve compromise, accompanying with injury of the other muscles innervated by the median nerve proximal to anterior interosseous nerve. Magnetic resonance imaging of the left proximal forearm revealed abnormally increased signal intensity of the pronator teres, flexor carpi radialis, proximal portion of flexor digitorum superficialis, and flexor digitorum profundus innervated by the median nerve on the T2-weighted images. This case shows the importance of knowledge about anatomic structures in considering intramuscular injection.
Pseudo-anterior interosseous nerve syndrome; Intramuscular injections
The knowledge on the anatomical variations of the deep flexor muscles is important due to its evolutionary significance. The flexor digitorum profundus is the deep flexor muscle of the forearm. It is a composite muscle with a dual nerve supply. The medial half of muscle is supplied by the ulnar nerve, and lateral half of the muscle is supplied by the anterior interosseous nerve, a branch of the median nerve. It flexes the distal phalanges of the medial four digits.
In the present case, we observed the presence of extensive cleavage of belly and tendon of flexor digitorum profundus to form flexor indicis profundus on the right side in an adult male cadaver. Flexor indicis profundus muscle is an example of progressive type of variation and it is usually asymptomatic, but it may cause compression of the anterior interosseous nerve, which can lead to compression neuropathy. If it is enlarged, it may simulate a ganglion.
Flexor digitorum profundus muscle; Flexor indicis profundus muscle; Anterior interosseous; Nerve; Compression Neuropathy; Ganglion
Tendon transfer for radial nerve paralysis has a 100 years history and any set of tendons that can be considered to be useful has been utilized for the purpose. The pronator tress is used for restoration of wrist dorsiflexion, while the flexor carpi radialis, flexor carpiulnaris, and flexor digitorum superficialis are variably used in each for fingers and thumb movements. The present study was a retrospective analysis, designed to compare three methods of tendon transfer for radial nerve palsy.
Materials and Methods:
41 patients with irreversible radial nerve paralysis, who had underwent three different types of tendon transfers (using different tendons for transfer) between March 2005 and September 2009, included in the study. The pronator teres was transferred for wrist extention. Flexor carpi ulnaris (group 1, n=18), flexor carpi radialis (group 2, n=10) and flexor digitorum superficialis (group 3, n=13) was used to achieve finger extention. Palmaris longus was used to achieve thumb extention and abduction. At the final examination, related ranges of motions were recorded and the patients were asked about their overall satisfaction with the operation, their ability, and time of return to their previous jobs, and in addition, disabilities of the arm, shoulder and hand (DASH) Score was measured and recorded for each patient.
The difference between the groups with regard to DASH score, ability, and time of return to job, satisfaction with the operation, and range of motions was not statistically significant (P>0.05). All of the patients had experienced functional improvement and overall satisfaction rate was 95%. No complication directly attributable to the operation was noted, except for proximal interphalangeal joint flexion contracture in three patents.
The tendon transfer for irreversible radial nerve palsy is very successful and probably the success is not related to type of tendon used for transfer.
DASH score; radial nerve palsy; tendon transfer
In this article, we present a case of humeral biepicondylar fracture dislocation concomitant with ulnar nerve injury in a seventeen year-old male patient. Physical examination of our patient in the emergency room revealed a painful, edematous and deformed-looking left elbow joint. Hypoesthesia of the little finger was also diagnosed on the left hand. Radiological assessment ended up with a posterior fracture dislocation of the elbow joint accompanied by intra-articular loose bodies. Open reduction-Internal fixation of the fracture dislocation and ulnar nerve exploration were performed under general anesthesia at the same session as surgical treatment of our patient. Physical therapy and rehabilitation protocol was implemented at the end of two weeks post-operatively. Union of the fracture lines, as well as the olecranon osteotomy site, was achieved at the end of four months post-operatively. Ulnar nerve function was fully restored without any sensory or motor loss. Range of motion at the elbow joint was 20-120 degrees at the latest follow-up.
Elbow injury; Fracture dislocation; Biepiconylar humeral fracture; Ulnar nerve injury
We report the results of staged flexor tendon reconstruction in 12 patients (12 fingers) with neglected or failed primary repair of flexor tendon injuries in zone II. Injuries involved both flexor digitorum profundus (FDP) and flexor digitorum sublimis (FDS), with poor prognosis (Boyes grades II–IV). The procedure included placing a silicone rod and creating a loop between the FDP and FDS in the first stage and reflecting the latter as a pedicled graft through the pseudosheath created around the silicone rod in the second stage. At a mean follow-up of 18 months (range 12–30 months), results were assessed by clinical examination and questionnaire. The mean total active motion of these fingers was 188°. The mean power grip was 80.0% and pinch grip was 76% of the contralateral hand. The rate of excellent and good results was 75% according to the Buck-Gramcko scale. These results were better than the subjective scores given by the patients. Complications included postoperative hematoma in two, infection in one, silicone synovitis in one (after stage I) and three flexion contractures after stage II. This study confirmed the usefulness of two-stage flexor tendon reconstruction using the combined technique as a salvage procedure to restore flexor tendon function with a few complications.
Flexor tendon; pedicled sublimis tendon graft; staged reconstruction
In this study the authors evaluate the clinical outcomes in patients with radial nerve palsy who underwent nerve transfers utilizing redundant fascicles of median nerve (innervating the flexor digitorum superficialis and flexor carpi radialis muscles) to the posterior interosseous nerve and the nerve to the extensor carpi radialis brevis.
A retrospective review of the clinical records of 19 patients with radial nerve injuries who underwent nerve transfer procedures using the median nerve as a donor nerve were included. All patients were evaluated using the Medical Research Council (MRC) grading system.
The mean age of patients was 41 years (range 17 – 78 years). All patients received at least 12 months of follow-up (20.3 ± 5.8 months). Surgery was performed at a mean of 5.7 ± 1.9 months post-injury. Post-operative functional evaluation was graded according to the following scale: grades MRC 0/5 - MRC 2/5 were considered poor outcomes, while MRC of 3/5 was a fair result, MRC grade 4/5 was a good result, and grade 4+/5 was considered an excellent outcome. Seventeen patients (89%) had a complete radial nerve palsy while two patients (11%) had intact wrist extension but no finger or thumb extension. Post-operatively all patients except one had good to excellent recovery of wrist extension. Twelve patients recovered good to excellent finger and thumb extension, two patients had fair recovery, five patients had a poor recovery.
The radial nerve is a commonly injured nerve, causing significant morbidity in affected patients. The median nerve provides a reliable source of donor nerve fascicles for radial nerve reinnervation. This transfer was first performed in 1999 and evolved over the subsequent decade. The important nuances of both surgical technique and motor re-education critical for to the success of this transfer have been identified and are discussed.
Nerve transfer; neurotization; brachial plexus; median nerve; radial nerve
We studied the outcome of patients with chronic distal radioulnar joint symptoms who were treated with excision of the distal ulna and reconstruction using the flexor carpi ulnaris tendon. Twelve patients with 14 wrists were assessed. Ten patients were posttraumatic, and two had bilateral surgery for rheumatoid arthritis. Average age was 37 years at time of operation. Follow-up averaged 20 months (9 months to 4 years). All patients except one reported improvement in pain symptoms. Grip strength of the operated hand as measured by dynamometer readings was 67% of the strength of the normal hand with five wrists achieving an excellent result in grip strength. Eleven patients reported a subjective improvement in functional activities. An improved range of motion was obtained in all patients. We discuss the importance and basis for ligamentous reconstruction following excision of the distal ulna and review the literature for other previously described procedures.
This study was designed to investigate the incidence of lateral root of the ulnar nerve through cadaveric dissection and to analyze its impact on myotomes corresponding to the flexor carpi ulnaris (FCU) assessed by electrodiagnostic study. Dissection of the brachial plexus (BP) was performed in 38 arms from 19 cadavers, and the connecting branches between the lateral cord and medial cord (or between lateral cord and ulnar nerve) were investigated. We also reviewed electrodiagnostic reports from January 2006 to May 2008 and selected 106 cases of single-level radiculopathy at C6, C7, and C8. The proportion of abnormal needle electromyographic findings in the FCU was analyzed in these patients. In the cadaver study, branches from the lateral cord to the ulnar nerve or to the medial cord were observed in 5 (13.1%) of 38 arms. The incidences of abnormal electromyographic findings in the FCU were 46.2% (36/78) in C7 radiculopathy, 76.5% (13/17) in C8 radiculopathy and 0% (0/11) in C6 radiculopathy. In conclusion, the lateral root of the ulnar nerve is not an uncommon anatomical variation of the BP and the FCU commonly has the C7 myotome. Needle EMG of the FCU may provide more information for the electrodiagnosis of cervical radiculopathy and brachial plexopathy.
Brachial Plexus; Ulnar Nerve; Electromyography; Radiculopathy
The Darrach and Sauvé-Kapandji procedures are considered to be useful treatment options for distal radioulnar joint disorders. Postoperative instability of the proximal ulnar stump and radioulnar convergence, however, may cause further symptoms. From October 1999 to May 2002, a total of 19 wrists in 15 men and four women, with an average age of 48.3 years, were treated by stabilizing the proximal ulnar stump with a half-slip of the extensor carpi ulnaris tendon using modified Darrach and Sauvé-Kapandji procedures. The average follow-up period was 77 months (range, 62 to 91 months). No patient complained of symptoms due to instability of the proximal ulnar stump. Grip strength improved in all wrists after surgery. Postoperative X-rays, including loading X-rays, showed improved alignment in both coronal and lateral planes. We concluded that stabilization of the proximal ulnar stump with ECU tenodesis is an effective procedure for treating distal radioulnar joint disorder after the Darrach and Sauvé-Kapandji procedures.
Ulnar stump; Extensor carpi ulnaris; Distal radioulnar joint; Darrach procedure; Sauvé-Kapandji Procedure
The purpose of this study was to report the operative findings in patients who underwent a secondary operation for cubital tunnel syndrome. A chart review was performed of 100 patients who had undergone a secondary operation for cubital tunnel syndrome by one surgeon. The mean age was 48 years (standard deviation 13.5 years). The most common complaint after primary surgery was increased symptoms in the ulnar nerve distribution (n = 55) and pain in the medial antebrachial cutaneous nerve distribution (n = 55). The most common operative findings included a medial antebrachial cutaneous nerve neuroma (n = 73) and a distal kink of the ulnar nerve (n = 57). This kink was noted as the nerve moved from its transposed position anterior to the medical epicondyle to its native position within the flexor carpi ulnaris. This study suggests that during primary surgery for cubital tunnel syndrome care should be given to avoid injury to the medial antebrachial cutaneous nerve, distal kinking of the ulnar nerve with transposition and pressure on the transposed nerve by the fascial flaps or tendinous bands.
Cubital tunnel syndrome; Surgery; Reoperation
Muscular variations of the flexor compartment of forearm are usual and can result in multiple clinical conditions limiting the functions of forearm and hand. The variations of the muscles, especially accessory muscles may simulate soft tissue tumors and can result in nerve compressions. During a routine dissection of the anterior region of the forearm and hand, an unusual muscle was observed on the left side of a 65-year-old male cadaver. The anomalous muscle belly arose from the medial epicondyle approxiamately 1 cm posterolateral to origin of normal flexor carpi ulnaris muscle (FCU), and from proximal part of the flexor digitorum superficialis muscle. It inserted to the triquetral, hamate bones and flexor retinaculum. Passive traction on the tendon of accessory muscle resulted in flexion of radiocarpal junction. The FCU which had one head, inserted to the pisiform bone hook of hamate and palmar aponeurosis. Its contiguous muscles displayed normal morphology. Knowledge of the existence of muscle anomalies as well as the location of compression is useful in determining the pathology and appropriate treatment for compressive neuropathies. In this study, a rare accessory muscle has been described.
Accessory muscle; Flexor carpi ulnaris muscle; Forearm; Ulnar nerve compression syndrome; Embryology
Avulsion of the flexor digitorum profundus tendon is a common injury to the hand that virtually always requires surgical repair for restoration of normal finger function.
We report a case of a Type III flexor digitorum profundus tendon avulsion in which the patient refused surgery yet attained nearly full active ROM and an excellent functional result via the formation of a pseudotendon, as observed on MRI obtained 2.5 years after the initial injury.
There are no reported cases of restoration of normal finger function after pseudotendon formation in a flexor digitorum profundus tendon avulsion injury.
Purposes and Clinical Relevance
This case shows the potential for pseudotendon to not only form but have adequate tensile strength to restore function in certain types of flexor tendon injuries.
Ulnar nerve neuropathy is one of the most common peripheral nerve dysfunctions. Elbow is the most common area affected by ulnar nerve which is mainly because of fractures or dislocations of this area. Delayed ulnar nerve palsy (Tardy Ulnar Nerve Palsy) in children due to a malpositioning of upper extremity during hospitalization is an uncommon cause of ulnar nerve injury which we have already reported it.
An eight-year-old conscious patient who had weakness, paresthesia and tingling in the right 4th and 5th fingers, as well as right claw hand deformity was evaluated, he had attended once before in 4 months ago due to head trauma in coma state. The child had no clinical and radiological indications of arm or elbow fractures causing nerve compression or entrapment. Elbow malposition had caused ulnar nerve neuropathy during hospitalization. Surgery was attempted, ulnar nerve decompression and anterior transposition done.
After three weeks post operatively, active physical therapy was started on the right upper extremity and the hand returned to normal activity after 6 months.
In patients with decreased level of consciousness or coma state who need prolonged hospitalization, the limbs must remain in correct position to prevent superficial nerve injuries and neuropathies. Furthermore, careful and scrutinized attention to the traumatic patients and doing on time and targeted imaging, regular follow up of patients, complete and perfect neurological examinations can prevent peripheral nerve injuries or develop on-time treatments which improve the patients' quality of life.
Ulnar nerve, Elbow malposition, Ulnar nerve decompression
Electrodiagnostic studies are traditionally used in the diagnosis of focal neuropathies, however they lack anatomical information regarding the nerve and its surrounding structures. The purpose of this case is to show that high-resolution ultrasound used as an adjunct to electrodiagnostic studies may complement this lack of information and give insight to the cause.
A 60-year-old male patient sustained a forearm traction injury resulting in progressive weakness and functional loss in the first three digits of the right hand. High-resolution ultrasound showed the presence of an enlarged nerve and a homogenous soft-tissue structure appearing to engulf the nerve. The contralateral side was normal. Surgery revealed fibrotic bands emanating from the flexor digitorum profundus muscle compressing the median nerve thus confirming the ultrasound findings.
A diagnostically challenging case of median neuropathy in the forearm is presented in which high-resolution ultrasound was valuable in establishing an anatomic etiology and directing appropriate management.
A 67 year old man with advanced neuropathic changes of both elbow joints associated with a demyelinating disease and diabetes mellitus is presented. The presenting complaint was caused by entrapment of the ulnar nerve within the elbow joint. The absence of diffuse peripheral neuropathy suggested that the demyelinating disease was the cause of the arthropathy. Operative exploration showed the ulnar nerve entrapped between the lateral side of the medial epicondyle and the olecranon. Excision of the medial epicondyle and anterior transposition of the ulnar nerves resulted in relief of the paresthesias and satisfactory sensory recovery. Excision of the trochlea was performed on the right elbow as well. It is suggested that patients with neuropathic or resorbing elbow joints who present with ulnar nerve entrapment should have prompt anterior transposition of the ulnar nerve. Impingement of the nerve between the bony processes of the elbow joint can cause mechanical disruption and irreversible injury.
The purpose of this study was to investigate whether synovium interposition between repaired tendon ends can integrate into the tendon repair and improve tendon healing strength in a canine tendon explant culture model.
Eighty flexor digitorum profundus tendons from ten mixed-breed dogs were used for this study. The flexor digitorum profundus tendons were assigned to two groups: repaired tendons with synovium implanted between the cut tendon ends and repaired tendons without any implantation between the tendon ends. The repaired tendons were cultured for either two or four weeks and then assessed mechanically for rupture strength and histologically.
The strength of the repaired tendons with the synovium interposition was significantly higher than the repaired tendons without interposition at both two and four weeks. The strength of the repaired tendons at four weeks was significantly higher than that at two weeks in both groups.
Interpositional synovial grafts have the potential to accelerate tendon healing when it is implanted at the repair site. The exact mechanism of this effect remains to be elucidated.
Flexor Tendon; Healing; Synovial Interposition; Mechanical Test; In Vitro
To present the case of an acute traumatic extensor carpi ulnaris (ECU) subluxation in a National Collegiate Athletic Association Division II female basketball player.
The ECU tendon is stabilized in the ulnar groove by a subsheath located inferior to the extensor retinaculum. The subsheath can be injured with forced supination, ulnar deviation, and wrist flexion, resulting in the ECU tendon subluxing in the palmar and ulnar directions during wrist circumduction. Several methods of intervention exist, but controversy remains on how to best treat this condition.
Distal ulnar fracture, ulnar collateral ligament sprain, triangular fibrocartilage complex lesion, lunotriquetral instability, distal radioulnar joint injury, pisotriquetral joint injury, ECU tendinopathy or subluxation.
The wrist was placed in a short-arm cast in slight extension and radial deviation for 4 weeks. At that time, the patient was still able to actively sublux the ECU tendon, so a long-arm cast was applied with the wrist in slight extension, radial deviation, and pronation for an additional 4 weeks. The ECU tendon was then found to be stable. She wore a rigid wrist brace for 3 more weeks while she pursued rehabilitation. At the final follow-up appointment, the ECU tendon remained stable, and the wrist was asymptomatic.
Subluxations of the ECU are rare. If the patient does not improve with conservative measures, surgical intervention is warranted to repair the sixth dorsal compartment.
A long-arm cast with the elbow flexed to 90° and the wrist in approximately 30° of extension, radial deviation, and pronation was appropriate treatment for this type of injury.
wrist; injury management; athletic injuries
Four cases of flexor tendon problems which developed after volar plate fixation of distal radius fractures are presented. All cases were associated with close contact of the screws or distal edge of the plate with the flexor tendons. Poor bone stock or multiple bone fragments allowing loosening of the plate or non-locking screws cause the hardware to irritate the flexor tendons and ultimately lead to rupture. The flexor tendons involved include the flexor carpi radialis, flexor pollicis longus and flexor digitorum superficialis, and flexor digitorum profundus to the index and long fingers.
Flexor tendon; Distal radius fractures; Volar plate fixation
The authors present a case study involving a 21-year-old male collegiate wrestler diagnosed with cubital tunnel syndrome.
Cubital tunnel syndrome is a condition brought on by an increase in the pressure exerted upon the ulnar nerve at the elbow within the cubital tunnel. The wrestler was diagnosed with cubital tunnel syndrome after 6 weeks of increasing disability and dysfunction.
Ulnar nerve contusion, ulnar nerve neuritis, cubital tunnel syndrome, thoracic outlet syndrome, C8 nerve root entrapment, double-crush syndrome, tumor.
The subject was treated conservatively for 3 months without resolution of the symptoms. Surgical treatment then involved a subcutaneous ulnar nerve transposition performed to decompress the cubital tunnel. Following surgery, the athlete participated in an aggressive rehabilitation program to restore function and strength to the elbow and adjacent joints. He was cleared for full unrestricted activity 15 days following surgery and returned to varsity athletic competition in 1 month.
Our literature review found no reported cases of cubital tunnel syndrome in wrestlers. Cubital tunnel syndrome is usually seen in throwing athletes and results from either acute trauma or repetitive activities.
The athletic trainer should consider cubital tunnel syndrome as a possible pathology for nonthrowing athletes when presented with associated signs and symptoms.
ulnar nerve entrapment; neuropathy
Selective peripheral nerve transfers represent an emerging reconstructive strategy in the management of both pediatric and adult brachial plexus and peripheral nerve injuries. Transfer of the lateral antebrachial cutaneous nerve of the forearm into the distal ulnar nerve is a useful means to restore sensibility to the ulnar side of the hand when indicated. This technique is particularly valuable in the management of global brachial plexus birth injuries in children for which its application has not been previously reported. Four children ages 4 to 9 years who sustained brachial plexus birth injury with persistent absent sensibility on the unlar aspect of the hand underwent transfer of the lateral antebrachial cutaneous nerve to the distal ulnar nerve. In three patients, a direct transfer with a distal end-to-side repair through a deep longitudinal neurotomy was performed. In a single patient, an interposition nerve graft was required. Restoration of sensibility was evaluated by the “wrinkle test.”
Lateral antebrachial cutaneous nerve; Brachial plexus birth injuries; Wrinkle test; Restore sensibility
The palmaris longus muscle is one of the most variable muscles in human anatomy. During a
routine anatomical dissection for medical students at Tottori University, we found
duplicate palmaris longus muscles in the bilateral forearms together with the palmaris
profundus muscle in the right forearm. The bilateral aberrant palmaris longus muscles were
observed at the ulnar side of the palmaris longus muscle and their distal tendons were
attached to the flexor retinaculum. The palmaris profundus muscle found in the right
forearm was located at the radial side of the flexor digitorum superficialis muscle. The
proximal tendon was originated from the anterior surface in the middle of the radius,
while the distal tendon coursed radial to the median nerve through the carpal tunnel,
finally inserting into the distal part of the flexor retinaculum. Both the palmaris longus
and aberrant palmaris longus muscles were innervated by the median nerve. The palmaris
profundus muscle was presumably supplied by the median nerve.
cadaver; forearm; regional anatomy; skeletal muscle