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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


DeQuervain’s tenosynovitis is a common cause of radial-sided wrist pain. Symptoms result from a narrow first dorsal compartment and associated tendinosis of the enclosed extensor pollicis brevis and/or abductor pollicis longus (APL). Surgical intervention, offered when conservative measures fail to adequately relieve symptoms, requires a detailed understanding of potentially aberrant anatomy in order to avoid persistence or recurrence of symptoms. We describe a case whereby the patient presented with complaints of thumb triggering in extension and associated disabling first dorsal compartment tendinosis. Intraoperatively, after supernumerary tendons were identified and addressed, the APL was at risk for subluxation over a prominent fibroosseous ridge. Routine first dorsal compartment release alone may have failed to address all of this patient’s pathology.

Concepts: Surgery, Failure, Extension, Extensor pollicis brevis muscle, Muscles of the upper limb, Tendinitis, Adductor pollicis muscle


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


Transecting the extensor pollicis longus (EPL) tendon and rerouting it through the first extensor compartment is an established technique for treating thumb-in-palm deformity (TIPD). An alternative technique that approximates the trajectory of the first extensor compartment without violating the compartment or transecting the EPL tendon can be accomplished by creating an artificial sheath from the extensor retinaculum to radialize the tendon glide path. This study compares this extracompartmental (EC) EPL transposition to the established, intracompartmental (IC) transposition by evaluating, in a cadaver model, the extent of thumb extension in both techniques.

Concepts: Logic, Extension, Extensor pollicis brevis muscle, Muscles of the upper limb, Posterior compartment of the arm


Boutonnière deformity of the thumb without rheumatoid arthritis or trauma is not widely recognised. This study aimed to investigate its prevalence, relation to sex and age, and identifying factors associated with the extensor mechanism using ultrasonography. We examined 248 thumbs from 127 participants who were asymptomatic for hand disorders and had no history of hand injury. Boutonnière deformity was identified in 20 thumbs of 17 participants and was significantly more prevalent among elderly participants than among young participants. No significant differences in sex or hand dominance were noted. The deformity had a significant effect on range of motion and grip and pinch strengths. The extensor pollicis brevis (EPB) tendon was significantly narrower in affected thumbs than in non-affected thumbs. The prevalence of boutonnière deformity without rheumatoid arthritis or trauma was 13%, and the deformity was associated with advanced age and a narrow EPB tendon.

Concepts: Rheumatoid arthritis, Rheumatology, Gerontology, Old age, Ageing, Arthritis, Finger, Extensor pollicis brevis muscle


In more advanced stages of trapeziometacarpal arthritis, the thumb metacarpal may develop an adduction contracture, leading to secondary hyperextension instability of the metacarpophalangeal joint. Following trapeziometacarpal arthroplasty, uncorrected substantial metacarpophalangeal hyperextension may contribute to ongoing Z-collapse deformity, weakness of pinch and grip, and patient perception of diminished function.

Concepts: Osteoarthritis, Knee, Arthritis, Joints, Extensor pollicis brevis muscle, Metacarpophalangeal joint, Lumbricals of the hand, Flexor pollicis brevis muscle


Tendon transfer with extensor indicis proprius (EIP) has been performed widely for reconstructing ruptures of the extensor pollicis longus because of its simplicity and clinical outcome. We experienced a rerupture of the extensor pollicis longus restored by incorrect tendon transfer because of a major unrecognized variation in the anatomy of the EIP. Surgeons should perform such transfer with a detailed knowledge of the possible anatomical variations to avoid such serious complications.

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


Background  Surgical management of de Quervain’s tenosynovitis is based on decompression of the first extensor compartment. A simple release of the first compartment can cause instability of the extensor pollicis brevis (EPB) and abductor pollicis longus (APL) tendons in zone seven of the extensors. The WHAT test (wrist hyperflexion and abduction of the thumb) is very effective in diagnosing this instability. Patients and Methods  In this retrospective monocentric study, we analyzed a case series of 10 patients all of whom underwent a reconstruction of the first extensor compartment using a retinacular graft because of symptomatic instability after decompression surgery. The reconstruction was a modified technique of the sixth compartment. Functional outcome and characteristics of the newly reconstructed pulley were examined by physical examination with the aid of ultrasound and internationally validated questionnaires. Results  Four patients had a good-to-excellent functional outcome, all of those had a maximum of two surgical procedures performed on the first extensor compartment. Six patients presented poor functional outcome. In four of them, more than two surgical procedures were performed. Minor residual instability was noted in six cases, found in both the groups. Conclusion  The reconstruction procedures on the first compartment seemed to be satisfactory in treating instability of the EPB and APL tendons after primary surgical release for de Quervain’s disease. Level of Evidence  Level IV, observational study without controls.

Concepts: Scientific method, Surgery, Reconstruction era of the United States, Reconstruction, Extension, Extensor pollicis brevis muscle, Muscles of the upper limb, Adductor pollicis muscle