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Concept: Extensor pollicis brevis muscle


A previous ultrasound study showed inflammation around the extensor pollicis longus tendon and surrounding structures at 6 weeks after manipulation, with or without pin fixation, and immobilization for distal radius fracture. Ultrasound examination after plating of distal radius fracture followed by early active mobilization of the wrist showed a short-lived inflammatory response, evident at 2 weeks but not at 6 weeks, around the extensor pollicis longus tendon (26 wrists examined) and flexor pollicis longus tendon (18 wrists examined). Early active mobilization of the wrist appears to limit the duration of inflammation around these tendons.

Concepts: Flexor digitorum profundus muscle, Wrist, Distal radius fracture, Flexor pollicis longus muscle, Extensor pollicis brevis muscle, Carpal tunnel, Flexor pollicis brevis muscle, Extensor pollicis longus muscle



Strong evidence indicates that highly repetitive manual work is associated with the development of upper extremity musculoskeletal disorders (MSDs). One of the occupational activities that involves highly repetitive and forceful hand work is manual pipetting in chemical or biological laboratories. In the current study, we quantified tendon displacement as a parameter to assess the cumulative loading exposure of the musculoskeletal system in the thumb during pipetting. The maximal tendon displacement was found in the flexor pollicis longus (FPL) tendon. Assuming that subjects' pipetting rates were maintained constant during a period of 1h, the average accumulated tendon displacement in the FPL reached 29m, which is in the lower range of those observed in other occupational activities, such as typing and nail gun operations. Our results showed that tendon displacement data contain relatively small standard deviations, despite high variances in thumb kinematics, suggesting that the tendon displacements may be useful in evaluating the musculoskeletal loading profile.

Concepts: Variance, Standard deviation, Flexor pollicis longus muscle, Extensor pollicis brevis muscle, Michigan, Musculoskeletal system


We investigated the flexor pollicis longus (FPL) tendon and median nerve in smartphone users by ultrasonography to assess the effects of smartphone addiction on the clinical and functional status of the hands.

Concepts: Ulnar nerve, Flexor pollicis longus muscle, Extensor pollicis brevis muscle, Carpal tunnel, Hand strength


This paper examines three cases of spontaneous ruptures of the extensor pollicis longus (EPL) with the extensor pollicis brevis (EPB) deformity. The patients ranged from 39 to 71 years old. Non-dominant hands were involved in all three cases. There were no trauma nor pathological cause of EPL ruptures. A tendon transfer using the extensor indicis proprius was performed in each case. Intraoperative findings showed hypoplastic EPB in one case and EPB defects in two cases. A weak or defective EPB puts an excessive load on the EPL, which might be one of the causes of spontaneous EPL rupture.

Concepts: Extensor pollicis brevis muscle, Muscles of the upper limb


Constructing a lateral key pinch (KP) is a universal aim of any functional upper limb surgery program for tetraplegia. Three stages are required: (1) activating the pinch mechanism by flexor pollicis longus tenodesis to the radius or by tendon transfer to the flexor pollicis longus, (2) simplifying the polyarticular chain, and (3) positioning the thumb column. We compared 2 techniques for accomplishing the latter stage, 1 utilizing arthrodesis of the carpometacarpal joint (CMC) and 1 that did not require arthrodesis of the CMC.

Concepts: Stage, Upper limb, Wrist, Flexor pollicis longus muscle, Extensor pollicis brevis muscle, Michigan, Carpometacarpal joint, Adductor pollicis muscle


Linburg-Comstock variation often connecting the flexor pollicis longus and flexor digitorum profundus of the index finger at a different level with significant discrepancy between clinical and cadaveric frequencies reported in the literature. Although this variation is quite prevalent, it is yet frequently unrecognized. The aim of this meta-analysis is to generate more accurate weighted frequency values of the Linburg-Comstock variation and to look for possible association with ethnicity, laterality, gender and side.

Concepts: Flexor digitorum profundus muscle, Finger, Index finger, Flexor pollicis longus muscle, Extensor pollicis brevis muscle, Carpal tunnel


Reconstruction of a tendon defect is a challenging task in hand surgery. Delayed repair of a ruptured flexor pollicis longus (FPL) tendon is often associated with tendon defect. Primary repair of the tendon is often not possible, particularly after debridement of the unhealthy segment of the tendon. As such, various surgical treatments have been described in the literature, including single-stage tendon grafting, 2-stage tendon grafting, flexor digitorum superficialis tendon transfer from ring finger, and interphalangeal joint arthrodesis. We describe step cut lengthening of FPL tendon for the reconstruction of FPL rupture. This is a single-stage reconstruction without the need for tendon grafting or tendon transfer. To our knowledge, no such technique has been previously described.

Concepts: Surgery, Flexor digitorum profundus muscle, Finger, Ring finger, Hand, Flexor pollicis longus muscle, Extensor pollicis brevis muscle, Muscles of the upper limb


Background  We evaluated the detection for screw penetration on the dorsal cortex of the radius in serial oblique, dorsal tangential, and radial groove radiographic views in volar plating fixation. Materials and Methods  Eight screw positions were set in each of the four cadaveric radii. Screw 1 was placed in the styloid subregion, whereas screws 2 and 3 were placed just proximal to the styloid and were defined for the radial region of the radius. Screws 4 (distal to the extensor pollicis longus [EPL] groove), 5 (the distal half of the groove), and 6 (the proximal half of the groove) were placed in the central region of the radius. Screws 7 (just medial to the groove) and 8 (sigmoid notch subregion) were positioned in the ulnar region of the radius. The screws were overlengthened by 1 and 2 mm and were evaluated in three radiographic views. Results  Penetrations in the radial region were fully visible in supinated oblique views with 1- and 2-mm overlengthened screws. The penetration of screw 4 was clearly observable over a considerable range of views. However, the 1-mm penetration of screw 5 was not detectable at any angle of projection. Detection of the ulnar region screw was the most difficult among the three regions with oblique views. In the dorsal tangential view, the 1-mm penetration of screw 4 was not observed in any of the four radii, but the penetration of screw 5 was detectable in all the radii. The screws 2, 3, 5, 7, and 8 were readily detectable. The screw 4 was barely seen in the radial groove view, while the screws 5 and 6 were readily detectable. Conclusion/Clinical Relevance  Appropriate combinations of these well-known radiological views are essential for the overall detection of penetrated screws during plating in distal radius fractures.

Concepts: Ulna, Circle, Wrist, Distal radius fracture, Extensor pollicis brevis muscle, Region, Radial nerve, Oblique projection


According to the anatomical literature, the extensor pollicis brevis (EPB) tendon passes through the first compartment and enters the base of the proximal phalanx of the thumb. There have been a few reports on the different types of supernumerary EPB tendons; however, an unusual course of the EPB tendon is extremely rare.

Concepts: Tendon, Extensor pollicis brevis muscle, Muscles of the upper limb, Thumb, Tendons