Reversed Palmaris Longus Research Articles

An Indigenous Study on The Palmaris Longus Muscle Anatomical Variations

Introduction: The Palmaris longus muscle is one of the superficial flexor muscles of the forearm that flexes the hand on the wrist and makes the palmar aponeurosis tense for gripping. It is variable both in number and form like inverted, doubled, split, three-headed or absent palmaris longus. These variabilities may cause clinical features due to abnormal pressure on the median and ulnar nerves. Its tendon can be used as a graft in various transplant surgeries. Aims & Objectives: This study was conducted to observethe number of cadavers showing anatomical variations of palmaris longus muscle in the Pakistani population. Place and Duration of Study: This study was conducted in the Anatomy Department of FMHCM&D, Lahore. The duration of the study was January 2019 - January 2022. Material & Methods: Cadaveric dissected upper limb specimens with normal palmaris longus were listed in Group: A, upper limbs having reversed palmaris longus were listed in Group: B, while upper limbs with absent palmaris longus were listed in Group: C. The RPL (reversed palmaris longus) muscle is the structure that is tendinous proximally and muscular distally (opposite of normal palmaris longus).Results were tabulated and percentages calculated. Results: It was observed that out of 80 dissected cadaveric upper limbs,77 (96.25%) showed normal palmaris longus while a right cadaveric upper limb (1.25%) showed anomalous palmaris longus with the reversed tendon. Palmaris longus muscle was found absent in two cadaveric left upper limbs (2.5%). Conclusion: Our study highlighted the percentage of different anatomical variations of the Palmaris longus muscle in terms of its presence with reversed tendons as well as its absence in a few human cadaveric upper limbs. This information may help anatomists, radiologists, physiotherapists and plastic surgeons.

Medianopathy caused by reversed palmaris longus: A case report

Medianopathy caused by reversed palmaris longus: A case report

O-NU002. Spectrum of nerve and muscle anatomic variants detected during neuromuscular ultrasound examination: A retrospective study

Introduction . Neuromuscular ultrasound has become an important diagnostic tool for neuromuscular disorders. The sonographic scanning protocol varies according to the provisional diagnosis but there are basic elements to assess like nerve and muscle size, echotexture, vascularity, nerve mobility, dynamic muscle assessment, in addition to the assessment of surrounding structures and anatomic variants. Recognizing anatomic variants is important as it may impact treatment and diagnosis. The aim of this study was to retrospectively analyze the frequency and the spectrum of anatomic variants detected during neuromuscular ultrasound examination. Methods . The medical records of 339 patients who were referred for neuromuscular ultrasound examination during the period from December 2014 to June 2020 were reviewed. The neuromuscular ultrasound reports and images archive of the patients were analyzed for presence of nerve and/or muscle anatomic variants. The records which did not show anatomic variants in the report and images archives were excluded from further analysis. The ultrasound images which showed anatomic variants were furtherly analyzed for the type of the anatomic variant, its detailed description, and its diagnostic or therapeutic impact if such information is available. Results . Nerve and/or muscle variants were found in 61 of 339 patients (17.9%). The most common muscle anatomic variants were accessory flexor digitorum superficialis within the carpal tunnel, bifid median nerve, persistent median artery, and ulnar nerve subluxation/dislocation at the ulnar groove. Uncommon anatomic variants were encountered including abnormal traverse of median nerve within the pronator teres muscle, reversed palmaris longus, and atypical position of tibial nerve at the medial ankle. Conclusion . Various nerve and muscle variants were detected in 17.9% of patients who were referred for neuromuscular ultrasound examination. Putting the anatomic variants in consideration when performing neuromuscular ultrasound examination is important as it may impact diagnosis and treatment.

Hypertrophied reversed palmaris longus muscle (pseudotumor) of the forearm causing median nerve compression: a case report

BackgroundThe palmaris longus muscle is considered one of the most anatomically variable muscles in the human body. Localized swelling of the forearm due to hypertrophy of the palmaris longus muscle is rare.Case presentationHere, we report a rare case of a 24-year-old Arab man who presented with a painful mass on his forearm with symptoms of median nerve compression. A full radiological assessment was performed, and he was treated conservatively.ConclusionThis case confirmed that a hypertrophied palmaris longus muscle can be the cause of swelling on the forearm and should always be considered in the differential diagnosis. With this report, we aimed to increase awareness regarding the unusual variations of palmaris longus muscle and the importance of using radiological investigations to establish a diagnosis.

Reversed palmaris longus muscle: a popular object of anatomical and surgical studies and some misdescriptions

Reversed palmaris longus muscle: a popular object of anatomical and surgical studies and some misdescriptions

Palmaris Longus Muscle Variations: Clinical Significance and Proposal of New Classifications.

The palmaris longus muscle is one of the most variable muscles in the human body and there have been numerous variations reported. The different palmaris longus variations are interesting not only from an anatomical point of view, but they could also have definite clinical significance. The aim of this study was to examine the different types of variations of palmaris longus muscle in the Bulgarian population. Over a period of 15 years, 56 formol-carbol fixed human cadavers were studied to investigate the different variations of palmaris longus muscle (PLM). Various anatomical variations of PLM have been reported: absence (2.68%); reversed palmaris longus coexisting with an additional abductor digiti minimi muscle (0.89%); digastric (0.89%); palmaris longus with intermediate muscle belly (1.79%) and duplication (1.79%). To reveal the wide variety of the types of palmaris longus muscle and their importance for clinical practice, we make a brief literature review concerning the different types of variations, their role in the median and ulnar neuropathy in the wrist or as structures simulating a soft tissue tumour and the application of palmaris longus tendon in plastic and reconstructive surgery as grafting material. We also present new systematic anatomical and clinical classifications of palmaris longus variations by dividing them into two simple groups.

Bilateral reversed Palmaris longus muscle with trifid insertion – A rare variation

The palmaris longus muscle (PL) is described as probably the most variable muscle in the human body, being variable both in number and form. 1 It can be absent in about 11% of bodies and this absence is more often in females and on the left side. 1,2 Bilateral absence is more common than unilateral absence. 1 Concerning the kind of muscle, it may be fleshy throughout its entire length or may be digastric. The muscle may have a proximal tendon or a distal one. It may be fleshy distally and tendinous proximally (Palmaris longus inversus), being known as the reversed palmaris longus muscle (RPL). The insertion is also highly variable and the muscle may be attached to the fascia of the forearm, the tendon of flexor carpi ulnaris, the flexor retinaculum, the pisiform or the scaphoid bones, the abductor pollicis brevis muscle, the fascia or muscles of the hypothenar eminence, one of the flexor tendons, or near the metacarpophalangeal joints. 1 The distal end of the PL is of clinical interest because of its possible relationships with the median and ulnar nerves. Usually the anatomical variations of the PL are not symptomatic. Nevertheless, a RPL can cause median nerve compression, 2,3 and less frequently ulnar nerve compression. 4

Embryological considerations on the bilateral reversed palmaris longus muscle: a case report in human

AbstractThis study describes a rare case of bilateral reversed palmaris longus muscle. An unusual variation was observed during the male cadaver dissection (60-year-old White). According to the literature, a reversed palmaris longus muscle may cause a compartment syndrome in the wrist area, carpal tunnel, and Guyon's syndrome. Moreover, this particular variation of the reversed palmaris longus muscle is rarely reported and has the potential to cause compression of both the median and ulnar nerves. Thus, the described variation is also useful to the hand surgeon, as the anomalous muscle is an anatomical landmark for operations at this area. Morphological variability and clinical significance are reviewed.

Sonographic diagnosis of anatomical variations associated with carpal tunnel syndrome

Bifid median nerve is an anatomic variation that occurs in about 18% of patients with symptoms suggestive of carpal tunnel syndrome and in about 15% of symptom-free subjects. Reversed palmaris longus is a rare anatomic muscular variation. The simultaneous presence of a bifid median nerve and a reversed palmaris longus has been very rarely described, usually during surgical exploration or in cadavers. We present two cases where ultrasound showed the presence of both abnormalities, allowing a correct diagnosis and influencing the treatment plan.

Reversed palmaris longus muscle: Anatomical variant – case report and literature review

The palmaris longus, a slender fusiform muscle, is especially prone to exhibiting anatomical variance relative to other muscles in the upper extremity. The most frequent anatomical variation is the completely absent palmaris longus, followed by the reversed, duplicated, bifid or hypertrophied palmaris longus muscles. The reversed palmaris longus muscle represents a structure that is tendinous proximally and muscular distally (opposite of the normal palmaris longus). The present report describes a case of reversed palmaris longus muscle, followed by a literature review to illustrate the wide spectrum of anatomical variations in the palmaris longus muscle and their clinical and surgical relevance.

Reversed palmaris longus muscle: Anatomical variant - case report and literature review

Reversed palmaris longus muscle: Anatomical variant - case report and literature review

Three-headed reversed palmaris longus muscle and its clinical significance

The palmaris longus muscle originates from the medial epicondyle of the humerus. After a short distance, almost in the middle of the forearm, the muscle belly is toggled into a broad tendon which is inserted into the flexor retinaculum and the palmar aponeurosis. After dissection of the left forearm of a 73-year-old female cadaver we found a reversed palmaris longus muscle. This means that the palmaris longus muscle was tendinous in its upper part and muscular in its lower part. Additionally, the muscle belly was triple, thus our finding was characterized as "three-headed reversed palmaris longus muscle". Rarely is the palmaris longus muscle double, whereas the three-headed reversed palmaris longus muscle is mentioned only once in the literature as a surgical finding, in a patient who suffered from edema and pain in the wrist [Yildiz, M., Sener, M., Aynaci, O., 2000. Three-headed reversed palmaris longus muscle: a case report and review of the literature. Surg. Radiol. Anat. 22, 217-219]. The overuse of the reversed palmaris longus muscle can lead to the muscle's local hypertrophy. According to the literature a reversed palmaris longus muscle may cause a compartment syndrome with pain and edema in the wrist's area, the carpal tunnel syndrome and Guyon's syndrome. The described variation is also useful to the hand surgeon, as the palmaris longus muscle is an anatomical landmark for operations at this area.

Anterior Interosseous Nerve Palsy After Cardiopulmonary Resuscitation in a Resuscitator with Undiagnosed Muscle Anomaly

Techniques for cardiopulmonary resuscitation (CPR) are now widely taught, not only to medical staff but also to the general public. At the same time, risks to the administrator of CPR, such as infection, postraumatic disorder, and myocardial ischemia (1–3) have also been reported. We report a case of anterior interosseous nerve (AIN) palsy after administration of CPR in a resuscitator with undiagnosed muscle anomaly. Case Report A 38-yr-old fisherman was admitted to the hospital with an inability to move the fingers of his right hand. He had performed unassisted CPR on a 70-yr-old man with cardiac failure for a period of 30 min. He had noticed dull pain over the right forearm during the procedure. The next morning he could not pinch powerfully between the thumb and index finger. On admission, he described dull pain and tenderness over the flexor muscles of the right forearm and the inability to pinch powerfully between the thumb and index finger to form a perfect “O” figure. The patient presented with a subcutaneous soft tissue mass on the volar aspect of the right wrist and along the forearm. The mass was chicken-egg size, elastic and soft, with clear margins, and not manifesting tenderness or signs of inflammation. Flexion of the interphalangeal joint of the thumb, index finger, and middle finger was weak, but the sensory examination and radiograph findings on the hand and forearm were normal. According to the diagnosis of AIN palsy, the patient was treated conservatively for 6 wk, but with no effect. Therefore, exploratory surgery was performed. The surgical examination showed that the flexor tendons of the thumb, index finger, and middle finger were normal. However, an anomalous muscle that originated from the radiocarpal aponeurosis lay on the volar side of the wrist and along the forearm, and its tendon was inserted reversibly over the proximal third of the radius and the tendinous area of the flexor muscles (Fig. 1). A subcutaneous soft tissue mass corresponded with the edematous belly of the anomalous muscle. The proximal part of the AIN was constricted by the fibrous band from the anomalous tendon and flexor muscles (Fig. 1). On the constricted site, the nerve was slightly swollen and edematous, with limited mobility, and kinked by flexion of the elbow. The AIN was freed from compression by the removal of the anomalous tendon and the fibrous band. Six weeks after the operation, flexion of the interphalangeal joint of the thumb and index finger was strengthened, and 6 mo later the powerful pinch was fully recovered.Figure 1: Intraoperative findings of patient’s right forearm. The anterior interosseous nerve is compressed by the fibrous band from the anomalous tendon and flexor muscles.Discussion The AIN is derived from the median nerve at the elbow and passes through the narrow space between muscles of the pronators and flexors of fingers and their fibrous band. It supplies the pure motor function to the flexor muscles of the thumb, the index and middle fingers, and to the pronator quadratus muscle. In this narrow space, the AIN is easily entrapped by a fibrous band (4,5), which results in entrapment neuropathy with the frequent flexion of the elbow. In general, the patient is treated conservatively and surgical exploration is only performed if the patient does not recover well under conservative treatment (4). In the present case, an anomalous palmaris longus muscle compressed the nerve. This muscle is known as the most variable muscle of the upper extremity (6) and causes nerve entrapment neuropathies of the ulnar and median nerves (7,8). The patient was a resuscitator and prolonged performance of chest compression induced AIN palsy. Schuurman et al. (9) reported four cases of effort-related median nerve compression resulting from a reversed palmaris longus muscle hypertrophy and an increased intracompartmental volume that leads to abnormal compartmental pressure increase during muscle activity (10). It is believed that the anomalous muscle increased in volume during exercise, causing local pressure on the AIN. The affected patient’s occupation as a fisherman required forearm muscle exertion while hauling in nets and was another factor promoting muscle hypertrophy with induction of a condition susceptible to nerve palsy. Peripheral neuropathies have various etiologies such as compression, stretch, ischemia, and direct nerve injury (11). The present palsy probably resulted from nerve ischemia by local compression to the AIN. The CPR technique requires too much effort to be continued for prolonged periods. Because our patient performed chest compressions for about 30 minutes without help, repetitive contraction and stretch of the arm muscles probably induced the nerve palsy. Clinicians should be aware of the effort-related nerve palsy (associated with the presence of muscle anomaly) after excessive muscle exertion such as CPR.

Reversed palmaris longus muscle on MRI: report of four cases.

Muscle anomalies around the wrist, in particular the palmaris longus muscle, may cause effort-related median nerve compression. A search of the medical records at our university hospital between 1994 and 1999 revealed four patients with an effort-related median nerve compression due to a reversed palmaris longus muscle. Magnetic resonance imaging was used in the patient work-up and showed an anomalous muscle in each case that had been missed initially. All four patients were free of pain after simple excision of the anomalous muscle. Awareness of muscle anomalies at the wrist on MR imaging is essential in evaluating patients with nerve compressions at the wrist. The purpose of this article is to heighten this awareness in radiologists.

Reversed palmaris longus muscle causing effort-related median nerve compression

Two cases of effort-related distal median nerve compression in the dominant forearm caused by a reversed palmaris longus muscle are presented. Simple resection of the muscle belly was performed. Carpal tunnel release was done in one case, but in retrospect this was probably not necessary.

Acute median nerve compression produced by reversed palmaris longus muscle

A case of acute median nerve compression with progressive sensory symptoms is reported. Early exploration revealed a hypertrophic reversed palmaris longus muscle as the compressing structure on the flexor aspect of the wrist. The symptoms of compression were relieved immediately after resection of the muscle.

Ulnar nerve compression caused by a reversed palmaris longus muscle

A case of ulnar nerve compression at the wrist caused by a reversed palmaris longus muscle is reported. We are not aware of any previous reports of ulnar nerve compression due to this particular muscle anomaly.

Median nerve compression secondary to bifid reversed palmaris longus

A case of median nerve compression in the forearm caused by a bifid reversed palmaris longus muscle is reported. We are not aware of any previous description of this particular anomaly associated with compression of the median nerve.

Median nerve compression at the wrist caused by a reversed palmaris longus muscle

A case of median nerve compression at the wrist caused by a reversed palmaris longus muscle is described. Symptoms included paresthesias in the median nerve distribution and swelling on the flexor aspect of the wrist resembling tenosynovitis. The patient was a 13-year old girl, which we believe is the youngest recorded case in the literature.