Extensor Compartment Of The Forearm Research Articles

Presumed Presence of Extensor Indicis et Digiti Medii Communis Muscle in a 70-Year-Old White Male Donor

Forearm extensor muscle variations can be diverse and, in some instances, rare. During a routine anatomical dissection of human cadaveric donors during the 2021 first-year medical gross anatomy course and 2021 graduate nursing advanced anatomy course at the Uniformed Services University of the Health Sciences, bilateral agenesis of the extensor carpi ulnaris muscle was noted in one 70-year-old white male donor. This variation is described as extremely rare in the literature. The presence of an extensor indicis et digiti medii tendon, a variant of the extensor indicis tendon, appeared to be evident in post-dissection photographs on the left hand. The presence of a duplicated extensor indicis proprious tendon appears to be evident on the right hand. However, further inspection of this region was impeded as the body was sent for cremation prior to the variation being identified. The presence of various juncturae tendinum was also noted bilaterally. Reported prevalence of extensor indicis muscle variants ranges from 0.75% to 13%, depending on the specific type or grouping of variations observed. Knowledge of variations in the extensor compartment of the forearm and wrist is crucial for orthopedic surgeons and specialists. Alteration of surgical approaches may be necessary if such a variation is present. Such variations can be options for grafts, resulting in minimal functional change to the grafted area due to the continued existence of other muscles performing similar functions. Knowledge of such variations, and alternative, synonymous names for them, is also important for anatomy instructors, who may need to assist students in identifying these rare variations during anatomical dissection.

A Cadaveric Study on the Anomalous Extensors of the Hand

Background: The hands play a pivotal role in skilled movements. Anomalous muscles of the extensors of the hand are seen usually in anatomical dissections and during surgeries. Variations of the muscles in the dorsum of hand may be asymptomatic or may cause dorsal wrist pain, particularly if a muscle belly encroaches on and obstruct the wrist's small extensor compartments deep to extensor retinaculum. Methods: A total of 54 upper limb specimens were used for the current study from the Anatomy Department of an undergraduate & postgraduate teaching Medical College in India. Incidence of additional muscle belly and its tendon in the posterior compartment of the forearm and dorsum of the hand were noted and photographed. Results: The anomalous muscle bellies and tendons in extensor compartment of forearm and dorsum of hand were observed in 10 limbs (18.5%) of 54 limbs. Of which, the extensor medii proprius (EMP) was 9.3%, extensor digitorum brevis manus (EDBM) was 3.7%. The numbers of the tendon of the extensor digitorum (ED) were varied in 3 limbs (5.6%). Conclusion: Knowledge of anatomical data of such variant muscles and additional belly or tendon in the extensor compartment of forearm and dorsum of hand is essential for surgeons to modify treatment plan, so as to avoid reporting error and of surgical procedures while operating on hand. KEY WORDS: Hand extensors, Anomalous muscles, Extensor mediiproprius, Extensor digitorum brevis manus, Extensor digitorum.

Tuberculous tenosynovitis involving wrist and extensor compartment of the forearm: Case presentation

Tuberculous tenosynovitis involving wrist and extensor compartment of the forearm: Case presentation

Anatomical variations of the extensor tendons of the fetal thumb.

The extensor pollicis longus (EPL) and brevis (EPB) and abductor pollicis longus (APL) are muscles located in the posterior compartment of the forearm. These muscles allow the thumb to move independently from the other four fingers by attaching to the thumb separately. This study's goal was to investigate the tendon variations and insertions of these muscles. Our study was conducted on 43 fetal cadavers (86 upper extremities) aged between 17 and 40weeks of gestation. This study investigated the tendon numbers and insertions of the EPL, EPB, and APL. The tendon numbers of the EPL and EPB were observed to range between 1 and 2, and the tendon numbers of the APL ranged between 1 and 5. The EPL was found to insert into the distal phalanx via the dorsal aponeurosis in all extremities. It was observed that the EPB tendons inserted into the proximal phalanx, distal phalanx, and dorsal aponeurosis. It was determined that the APL tendons inserted into the basis of the first metacarpal, abductor pollicis brevis, opponens pollicis, and trapezium bone. Knowing the tendon variations and insertions of the EPL, EPB, and APL muscles during the fetal period will be useful in planning treatments to correct the congenital thumb anomalies and the loss of function after injury.

Extensor Indicis Radialis and Extensor Medii Proprius Associated with an Unknown Fibromuscular Slip: a Case Report

Posterior compartment of forearm and hand is among the most variable parts of the human body. During a routine dissection, we found two anatomical variants in the right forearm and hand of an 84-year-old male cadaver including the extensor indicis radialis and the extensor medii proprius associated with a fibromuscular slip. Histological analysis using hematoxylin and eosin staining revealed that this unusual fibromuscular slip associated with the extensor medii proprius was composed of dense connective tissue along with small amount of skeletal muscle fibers, and the innervation from the posterior interosseous nerve. Based on the existing literature, a fibromuscular slip associated with a hand extensor tendon on the dorsum of hand has never been reported. Further studies are needed to clarify the evolutionary origin of this structure, although it resembles to a certain extent the dorsometacarpales, a group of muscles that were once present in our mammalian ancestors.

A bilateral variant accessory belly of extensor indicis muscle in posterior compartment of forearm: An anatomical variation

A bilateral variant accessory belly of extensor indicis muscle in posterior compartment of forearm: An anatomical variation

Surgical management of the proximal injury to the nerves of the upper extremity: strategy at overcoming multiple critical gaps

Aim of the study — to evaluate the outcomes of reconstruction procedures at complete injuries of brachial plexus in subclavicular region. The retrospective analysis of the reconstruction procedures in 3 men and one woman (mean age 36,4 years) with complete injury of brachial plexus in subclavicular region was conducted. Injury to musculocutaneuos, median, ulnar and radial nerves was accompanied by axillary (2 cases) or brachial (2 cases) artery injury. One patient had no injury to musculocutaneous nerve within the injury’s structure. All patients underwent surgical reconstruction of the neural structures 4,8 months (mean term) post initial vascular surgery. The autografting was the main reconstruction procedure of the long nerves of the upper extremity at their critical gap (mean gap 10,5cm) with donor-nerves of the small (sural nerve) and large (ulnar nerve) cross sectional diameter. Both motor and sensory components of recovery were evaluated with MRC Scale and Seddon Scale respectively. Each patient evaluated the recovered median nerve mediated functions with Brief Michigan Hand Questionnaire. It was revealed that one patients showed poor recovery of the entire complex of the muscles of the upper and lower arm (MRSC 2 points or lower). Two patients showed good recovery of the biceps brachii muscle (MRCS score 5 points) on 14th and 13th month respectively. Mean MRC Scale score among three patients for the muscles of the anterior compartment of the forearm was: 3,3 points for m. flexor pollicis longus, 3,6 points for mm. flexores digitorum and 4 points for m. flexor carpi radialis respectively. Mean MRC Scale score among three patients for the muscles of the posterior compartment of the forearm was: 2,6 points for m. extensor pollicis longus, 3,3 points for m. extensor digitorum sublimis and 4 points for radial wrist extensors respectively. The median nerve mediated sensation recovered to 2,3 points on Seddon scale. Only one patient showed effective recovery of the thumb opposition. Loss of ulnar nerve mediated functions was expectable among all 4 enrolled patients, thereafter we observed no recovery of key pinch and diagonal volar grip. Three patients showed recovery of transversal volar grip only. Mean Brief MHQ score was 55,55 points – unsatisfactory recovery. The reconstruction of the ulnar nerve, thereafter recovery of the “intrinsics”, should be the priority in terms of reanimation of the basic grips and pinches of the upper extremity – one should avoid harvesting of the ulnar nerve at multiple nerve injury cases; the expectable loss of functions at the utililization of the radial nerve as a donor nerve, could be easily recompensed with the tendon transfer procedures in later terms.

Anatomic Variations of the Hand Extensor Muscle Tendons

Variations of muscles on the dorsal aspect of the forearm are seen very common. These variations can be symptomatic but generally they are diagnosed incidentally. On the posterior compartment of forearm, extensor carpi radialis brevis related to abduction of the wrist and extensor digitorum related to extension of the wrist and fingers. This case report showed rare variations of extensor carpi radialis brevis and extensor digitorum muscles. During routine dissections of the extensor compartment of the forearm for anatomy education, it was observed that extensor carpi radialis brevis muscle had an accessory head which attached to dorsum and proximal phalanx of the index finger. Besides, it was found that extensor digitorum muscle divided into three tendons distally. When we followed these tendons, it was observed that tendon of index finger was absent and other three tendons went to middle, ring and little fingers. Accessory muscles located on the extensor compartment of the forearm are seen common. They can be reason of the symptoms of the nerve entrapment. Besides, these unusual muscles may confuse radiologists, surgeons and anatomists. In order to prevent diagnostic errors and avoid surgical complications, these anatomical variations should be well-known.

Unilateral accessory muscles of forearm-and its clinical implications

An accessory or aberrant musculature may stimulate a ganglion or a soft tissue tumour or if in close proximity to a nerve, it may cause pressure neuritis. Identification of these variations is important in defining the anatomical features for clinical diagnosis and surgical procedures. During routine cadaveric dissection of the forearm in the department of anatomy, we observed an accessory muscle in the flexor compartment and additional extensor carpi radialis longus muscle in the extensor compartment of the forearm in left upper limb of a middle aged female cadaver. The accessory muscle belly has taken its tendinous origin from the medial surface of the ulna deep to the flexor digitorum superficialis and crossed the median nerve from medial to lateral, when traced below in the carpal tunnel it merged with the tendon of the index finger of flexor digitorum superficialis. An additional extensor carpi radialis longus muscle with unusual course of radial nerve in the extensor compartment of the forearm was found on the medial side of brachioradialis and superficial to extensor carpi radialis longus and its tendon ended by getting inserted into the base of the dorsal surface of the second metacarpal bone. Although many anatomical variations of flexor digitorum superficialis and extensor carpi radialis longus muscle were reported in the past, we describe a rare case, first of its kind, which to our knowledge has not been mentioned in the literature till date. Such variations are clinically significant in the anatomical, surgical and radiological procedures. Asian Journal of Medical Sciences Vol.8(2) 2017 94-96

Gross Anatomical Observations of Abductor Pollicis Longus Muscle—A Cadaveric Study

Abductor pollicis longus is a muscle of deep group of extensor compartment of the forearm. It is an abductor of the thumb. The aim of the study is to observe the variations in the number of tendons and the point of distal attachment of this muscle tendon. This study included 32 upper limbs of cadavers, both male and female which were dissected in the Department of Anatomy, Kasturba Medical College, Manipal. A significant variations were observed in the abductor pollicis longus. Majority of muscle having more than one tendon. Tendons vary from 1–4. Their point of insertion also varies. Some are inserted to 1st metacarpal, some to trapezium and some are to the both. Also found one which is attached to base of proximal phalynx of the thumb. This muscle helps in movement and stabilization of thumb. Accessory tendons have been found to be a feasible option for tendon transplants in reconstructive surgeries of the hand. Injuries in one tendon can be compensated by the remaining tendons. Thus, awareness in the variations of this muscle is important for surgeons.

Gantzer muscles and their applied aspects: an exceptional finding

Anatomical variations are typically more common in the extensor compartment of the forearm, but uncommon in the flexor compartment. The presence of such anatomical anomalies is not usually noticed until the normal functions of an individual become hindered, or when these anomalies become a surgical problem. During routine dissection curriculum, we encountered a rare finding of bilateral Gantzer muscles in a cadaver. We describe the relationship between the Gantzer muscle and anterior interosseous nerve syndrome.