Finger Tendon Research Articles

Biomechanical analysis of force distribution in human finger extensor mechanisms.

The complexities of the function and structure of human fingers have long been recognised. The in vivo forces in the human finger tendon network during different activities are critical information for clinical diagnosis, surgical treatment, prosthetic finger design, and biomimetic hand development. In this study, we propose a novel method for in vivo force estimation for the finger tendon network by combining a three-dimensional motion analysis technique and a novel biomechanical tendon network model. The extensor mechanism of a human index finger is represented by an interconnected tendinous network moving around the phalanx's dorsum. A novel analytical approach based on the “Principle of Minimum Total Potential Energy” is used to calculate the forces and deformations throughout the tendon network of the extensor mechanism when subjected to an external load and with the finger posture defined by measurement data. The predicted deformations and forces in the tendon network are in broad agreement with the results obtained by previous experimental in vitro studies. The proposed methodology provides a promising tool for investigating the biomechanical function of complex interconnected tendon networks in vivo.

A Rare Case of Multifocal Giant Gell Tumor of the Tendon Sheath Involving Both the Hand and the Foot

A Rare Case of Multifocal Giant Gell Tumor of the Tendon Sheath Involving Both the Hand and the Foot

Mycobacterium tenosynovitis With Rice Bodies

Rice bodies are known to form in patients with certain inflammatory conditions such as rheumatoid arthritis and seronegative inflammatory arthritis. However, in this article, we focus on the infectious causes of tenosynovitis of the hand, especially mycobacterial infections, and the importance of diagnosis before treatment, especially before a steroid injection is given. We present a patient with tenosynovitis of the flexor tendon of the third finger who underwent an incision and drainage procedure. During the operation, multiple soft white beads were discovered and identified as rice bodies. Cultures of the specimen were positive for Mycobacterium avium intracellulare.

Table Saw Injuries

Table saws are ubiquitous devices in professional, home, and school woodshops that have the potential to cause severe injuries. Many of these injuries results in finger and thumb tendon, nerve, and vascular damage or amputation. Long-term outcomes of these injuries can include functional and sensory deficits. Table saw manufacturers are required to equip saws with blade guards to prevent blade contact; nevertheless, treatment of table saw injuries is a common occurrence in U.S. emergency departments. The authors performed a literature search using PubMed and the Cumulative Index to Nursing and Allied Health Literature to compile epidemiology data relevant to table saw injuries. The authors also reviewed the U.S. Consumer Product Safety Commission's briefing package on table saw blade contact injuries. Over 30,000 table saw injuries occur annually. Fingers and hands are the most frequently injured body parts, and lacerations are the most common injuries. Individuals suffering from occupational injuries tend to be younger than those injured during amateur woodworking. A small but important minority of injuries are to students participating in school shop classes. Medical costs for the treatment of table saw injuries are estimated at more than $2 billion every year. SawStop technology stops the saw blade when contact with skin is made, resulting in a small cut rather than a more complicated laceration or amputation. The application of this novel technology in saw designs can prevent serious injuries that deleteriously affect lives at the personal and societal levels.

Closed Extensor Indicis Proprius Tendon Rupture Presenting Mass Clinic on Dorsal Side of the Wrist

A 28 years old male constructor referred to our clinic for a mass on the dorsal side of the left wrist. He has constricted his hand to the plaster cast machine in hyperflexion posture one month ago and swelling complaint has begun one week ago. MRI revealed tenosynovitis. A wide organized hematoma was appeared in the 4th extensor compartment in the surgical exploration of the patient and it was observed that extensor indicis proprius tendon has detached from the musculotendineous region. Common extensor tendon of the second finger was intact. Tenodesis to the distal end of the ruptured tendon to the intact common exten sor tendon by side to side surgical suture technique was performed. There were complete extension in the 2nd finger at the 2nd month after the surgery.

Anatomical variations of the hand extensors

This study was performed to investigate the anatomy and variations of the human extensor tendons of the fingers and their intertendinous connections. Ninetyfive upper limbs of adult cadavers were dissected. The variations in the extensor tendons of the fingers, both proximal and distal to the extensor retinaculum, and their mode of insertion were observed. Also, the intertendinous connections were explored and the obtained data were analysed. The extensor pollicis longus and brevis tendons were found to be single, doubled or, rarely, absent. Their insertion could be traced to either the proximal phalanx, or through the extensor expansion to both phalanges, or rarely to the distal phalanx of thumb. The extensor indicis had a single tendon in all specimens. In the majority of specimens, extensor digitorum had no independent slip to the little finger; it gave off a single tendon to the index, double tendons to the middle finger and triple tendons to the ring finger. Extensor digiti minimi muscle often had double or triple tendons distal to the extensor retinaculum. Three types of juncturae tendinum (JT) were identified between the tendons of extensor digitorum in the 2nd, 3rd and 4th intermetacarpal spaces (IMS) of hands. Types 1 and 2 JT were seen in the three IMS. Type 3 JT was the most frequently identified of all juncturae and was always absent in the 2nd IMS. The percentages of the present data were compared with other researchers'data.

Operative Behandlung der Krallenhand mittels Lassoplastik

The aim is correction of claw deformity of the fingers by intrinsic paralysis. Indications are claw deformity of fingers caused by palsy or functional loss of the interosseus or lumbrical muscles as far as the function of the superficial and deep flexors of the finger is intact. Contraindications are loss or paralysis of finger flexors supplied by the median nerve, fixed extension or flexion contracture of the finger joints, osteoarthritis and other malfunctions of the finger joints, no active flexion and extension of the interphalangeal joints due to compromised tendon gliding. Relative: Upper ulnar nerve palsy with functional loss of the deep flexor of the small and ring finger and possibly of the middle finger. The operation technique involves detachment of the flexor digitorum superficialis IV tendon (FDSIV) distal to Camper's chiasm, division of the tendon into separate strips, interweaving of each tendon strip into the proximal part of the A2 pulley of the affected fingers. In cases of claw deformity of all fingers it may be advantageous to apply the superficial flexor tendon of the long finger in addition to the FDSIV tendon as otherwise the FDSIV tendon has to be divided into four strips resulting in relatively thin tendon strips. If the FDSIII and IV tendons are applied, the two strips of the FDSIV tendon are used for lassoplasty of the small and ring fingers and the FDSIII tendon for lassoplasty of the middle and index fingers. Postoperative management includes immobilization of the operated fingers by a dorsoulnar forearm plaster cast including the metacarpophalangeal joints which are flexed to 70°. After 2weeks replacement of the cast by a thermoplastic splint for another 4weeks. During the whole period exercises for the finger and thumb should be carried out. From April 2003 to June 2012 a total of 17patients, 8female and 9male were surgically treated for claw deformity. The dominant hand was affected in seven patients. The average age was 46 ± 15 (22-80) years, the average interval from onset of ulnar palsy to lassoplasty was 61 ± 91 (3-288) months. The final follow-up was performed after an average of 42 ± 32 (2-112) months. Claw deformity was resolved in 14 out of the 17patients. The grip strength was on average 58 ± 28 % (11-96%) of the unaffected hand, the mean disabilities of the arm, shoulder and hand (DASH) score was 32 ± 18 (5-68) points and the degree of patient satisfaction 7 ± 2 (0-10). According to own results and those in the literature lassoplasty can be recommended for the treatment of claw deformity.

Wiederherstellung der Daumenendgelenkbeugung durch Transposition der oberflächlichen Beugesehne des Ringfingers

Restoration of active thumb flexion at the distal joint. Loss of active flexion of the interphalangeal (IP) joint of the thumb if there is a transection of the flexor pollicis longus (FPL) tendon at the tendon channel of the thumb or thenar and direct suture is not possible but the tendon channel is intact, as alternative procedure to a free tendon graft if the transection is proximal to the tendon channel and the muscle of the FPL is contracted/injured or the FPL tendon is unharmed but the FPL muscle is partially or complete paralyzed. Insufficiency of the FPL tendon channel, impairment of the superficial or deep flexor tendon of the ring finger, limited passive motion of the proximal and distal thumb joints, acute local general infection and non-compliance or incapacity of the patient. The surgical technique depends on the necessity of transosseous refixation of the FDS IV at the base of the distal phalanx of the thumb or the possibility of woven sutures through the FPL proximal to the tendon channel. If the tendon channel is intact the distal part of the FPL tendon is shortened to 1cm, the FDS IV tendon is cut distal to the chiasma of Camper, pulled through the carpal tunnel and moved into the channel of the FPL tendon and fixed transosseously through the base of the distal phalanx of the thumb. If the transection of the FPL tendon is located proximal to the tendon channel and muscle of the FPL is injured, FDS IV tendon will be woven using the Pulvertaft technique through the FPL tendon at the distal forearm. Postoperative 6weeks motion of thumb flexion without resistance in relieved position of the thumb through a thermoplast splint and 6weeks of functional use of the hand with increasing weight bearing. In this study 10patients with FDS IV transposition to reconstruct an isolated rupture of the FPL tendon could be followed for an average of 4.1years postoperatively. The active range of motion of the IP joint of the thumb averaged 65° (10-100°), 8/10patients achieved an equal active and passive range of motion of the IP joint of the thumb, in 2patients some flexion insufficiency remained, 9 patients could reach the fingertip of the small finger with the thumb and 1patient lacked 3mm. Contracture of the proximal thumb joint developed in two patients. After removal of the FDSIV tendon two patients developed contracture of the PIP joint of the ring finger. The grip force was reduced to 81 %, lateral grip to 83 % and pinch grip to 77 %. The DASH score averaged 18 (0-31) and 8/10patients would choose to undergo this surgery again.

Variantes Anatómicas dos Músculos Extensores dos Dedos da Mão

The extensor tendons of fingers are subject of many variations, some of them quite frequent. The dissection of the posterior region of forearm and hand was carried out, and the anatomical variations were documented. In Case 1 the extensor digitorum divided into 5 tendons: one for the index finger, one for the middle finger, two for the ring finger and one for the little finger; the extensor indicis proprius divided into two tendons: one for the index and one for the middle finger. In Case 2 the extensor digitorum divided into 4 tendons: one tendon joined the extensor pollicis longus, one tendon for the index, one for the middle finger and one for the ring finger with one slip to the little finger; the extensor indicis proprius divided into two tendons, one for the index and one for the middle finger; the extensor digiti minimi divided into two slips for the little finger. The existence of a double tendon from extensor digitorum for the ring finger is described in several studies. The tendinous slip from extensor digitorum to extensor pollicis longus is not a frequent finding. The double tendon from extensor digiti minimi may occur in 60 to 90% of cases. The knowledge of the most common variations of the tendons of extensor muscles is very important in surgical practice.

Simultaneous juxta-epiphyseal proximal phalanx fracture with flexor tendon entrapment in a child

Juxta-epiphyseal/Salter-Harris fractures are the most common hand fractures in children and the proximal phalanx is involved in most cases. In the absence of soft-tissue interposition, these growth plate injuries are simple to reduce and are stable. However, in some cases, flexor tendon entrapment could be present. We report on an 11-year-old girl who sustained a fall onto her outstretched hand with subsequent injuries in her long, ring, and small fingers. Plain radiographs showed a severely displaced juxta-epiphyseal proximal phalanx fracture in her ring finger associated with mildly displaced juxta-epiphyseal proximal phalanx fractures of the long and small fingers. Fracture reduction could not be achieved after a closed reduction attempt. An open reduction and stabilization using Kirschner wires was performed in the fourth and fifth fingers, because of entrapment of the flexor digitorum profundus tendon. Excellent functional as well as radiological outcomes were achieved. These types of injuries are very uncommon and a high index of suspicion on the basis of clinical as well as radiological findings is needed to make an early diagnosis and for adequate treatment. Multiple proximal phalangeal fractures could be associated with the simultaneous entrapment of flexor tendons in different fingers as in our case; this is important to keep in mind as it is useful when planning the definitive surgical treatment and doing so will have a positive impact on the final functional as well as radiological outcomes.

The relationship of trigger finger and flexor tendon volar migration after carpal tunnel release

It has been suggested that the increased frequency of trigger finger (TF) after carpal tunnel release (CTR) may be caused by the volar migration of the flexor tendons at the wrist altering the tendon biomechanics at the A1 pulley. This hypothesis has not been validated. We performed pre- and post-operative ultrasonography (USG) on the affected wrists of 92 patients who underwent CTR. Pre-operative USG was performed in neutral with no tendon loading; post-operative USG was performed in neutral unloaded and in various positions of wrist flexion whilst loading the flexor tendons with gripping. The mean volar migration of the flexor tendons after CTR was 2.2 (SD 0.4) mm in the unloaded neutral position. It was 1.8 (SD 0.4) mm in patients who did not develop TF and 2.5 (SD 0.5) mm in those who did (p = 0.0067). In loaded wrist flexion, the mean volar migration of flexor tendons after CTR in patients who did not develop TF and those who did was 2.1 and 3.0 mm in 0° flexion; 3.2 and 3.9 mm in 15° flexion; 4.3 and 5.1 mm in 30° flexion; and 4.9 and 5.8 mm in 45° flexion, respectively. There were significant differences between patients with and without TF at each flexion angle. Our data indicate that patients with greater volar migration of the flexor tendons after CTR are more likely to develop TF. This conclusion supports the hypothesis that the occurrence of TF after CTR may be caused by the bowstringing effects of the flexor tendons.

FLEXOR TENDON RUPTURE OF THE LITTLE FINGER CAUSED BY CALCIUM PYROPHOSPHATE DIHYDRATE CRYSTAL DEPOSITION DISEASE OF THE PISOTRIQUETRUM JOINT

We report a case of closed rupture of the flexor tendons of the little finger caused by calcium pyrophosphate dihydrate crystal deposition disease of the pisotriquetrum joint. The patient could not flex the little finger and did not have wrist pain. Plain radiographs of the affected wrist joint showed severe arthritic changes of the pisotriquetrum joint and calcification around the joint. At operation, the pisotriquetrum joint capsule was ruptured and involved the flexor tendon of the little finger. The distal stump of the flexor tendon was transferred to the flexor tendon of the ring finger, and the pisiform was resected. Histological examination with polarized light microscopy revealed crystals showing weakly positive birefringence in the calcification.

Emergent Tendon Transfer in Hand Trauma: A Case Report

In this report we describe our encounter of a case of hand trauma referred to our center presenting with incomplete left thumb amputation at metacarpal level with extensor pollicis longus (EPL) and flexor pollicis longus (FPL) tendon avulsion from the tenomuscular junction. After metacarpal bone fixation the ulnar digital artery was anastomosed and the digital nerves were coapted. Transfer of extensor indicis proprius (EIP) to EPL and side-to-side suturing of the FPL to the deep flexor tendon of the index finger were performed.

Anomalous Extensor Indicis Proprius Muscle

Anomalous Extensor Indicis Proprius Muscle

Development of Active Rehabilitation Device of Hand Joint

If the hand joints patients have not been taking autonomic or external force rehabilitation, they might become disabled, even leading the cause ofirreversible disability eventually. Generally speaking, the medical treatment of rehabilitation has been doing by physical therapist by providing patients with external forces rehabilitation assistance as far as we know currently. For the purpose of both of reducing the workload of physical therapists and providing the quantitative data obtained during the rehabilitation process so as for physical therapist’s reference. This research will build an automatic finger stretch and grip control system by using the Human- Machine Interface for operation control. It can be done by physical therapist or physical doctor to set the operating conditions so as to help the patients with their finger joints motion so as to achieve the rehabilitation effect of their fingers. This research is trying to integrate the mechanism and control technology mainly. With regards to the control technology, it uses a micro chip so as to lead the motions of the stretch & grip for finger rehabilitation by a signal processing control servo motor. And its operation interface is using an embedded system along with Visual Studio compiling software so as to touch input the operating conditions. The system operation functions are including single finger joint motion orsynchronized actuation of all fingers and the setting of the cycle numbers. Furthermore, in order to soften the finger tendons so as to promote the rehabilitation effect during the rehabilitation process, the system adds external steam in so as to control the internal temperature & humidity of the rehabilitation box and apparently, the whole finger automatic stretch & grip control system will be better owing to it.

Finger Tendon Travel Associated with Sequential Trigger Nail Gun Use

OCCUPATIONAL APPLICATIONS This article reports a method for assessing finger tendon motion associated with the use of a sequential actuation trigger pneumatic nail gun. The two-stage actuation process of the sequential actuation trigger reduces risk of nail puncture injury from unintended nail discharge (relative to the higher risk of the contact actuation trigger). However, widespread adoption of the sequential actuation trigger nail gun throughout the construction industry has been hindered by beliefs about productivity and musculoskeletal concerns about the repetitive trigger actuation and finger motion for each nail fired. Though existing guidelines for finger tendon travel exposure are not well established, predictions derived with the present method combined with productivity standards suggest insufficient evidence to contradict the safety-based recommendation to adopt the sequential actuation trigger trigger. TECHNICAL ABSTRACT Background: Pneumatic nail guns used in wood framing are equipped with one of two triggering mechanisms. Sequential actuation triggers have been shown to be a safer alternative to contact actuation triggers because they reduce traumatic injury risk. However, the sequential actuation trigger must be depressed for each individual nail fired as opposed to the contact actuation trigger, which allows the trigger to be held depressed as nails are fired repeatedly by bumping the safety tip against the workpiece. As such, concerns have been raised about risks for cumulative trauma injury, and reduced productivity, due to repetitive finger motion with the sequential actuation trigger. Purpose: This study developed a method to predict cumulative finger flexor tendon travel associated with the sequential actuation trigger nail gun from finger joint kinematics measured in the trigger actuation and productivity standards for wood-frame construction tasks. Methods: Finger motions were measured from six users wearing an instrumented electrogoniometer glove in a simulation of two common framing tasks—wall building and flat nailing of material. Flexor tendon travel was calculated from the ensemble average kinematics for an individual nail fired. Results: Finger flexor tendon travel was attributable mostly to proximal interphalangeal and distal interphalangeal joint motion. Tendon travel per nail fired appeared to be slightly greater for a wall-building task than a flat nailing task. The present study data, in combination with construction industry productivity standards, suggest that a high-production workday would be associated with less than 60 m/day cumulative tendon travel per worker (based on 1700 trigger presses/day). Conclusion and Applications: These results suggest that exposure to finger tendon travel from sequential actuation trigger nail gun use may be below levels that have been previously associated with high musculoskeletal disorder risk.

Trigger finger, tendinosis, and intratendinous gene expression

The pathogenesis of trigger finger has generally been ascribed to primary changes in the first annular ligament. In contrast, we recently found histological changes in the tendons, similar to the findings in Achilles tendinosis or tendinopathy. We therefore hypothesized that trigger finger tendons would show differences in gene expression in comparison to normal tendons in a pattern similar to what is published for Achilles tendinosis. We performed quantitative real-time polymerase chain reaction on biopsies from finger flexor tendons, 13 trigger fingers and 13 apparently healthy control tendons, to assess the expression of 10 genes which have been described to be differently expressed in tendinosis (collagen type 1a1, collagen 3a1, MMP-2, MMP-3, ADAMTS-5, TIMP-3, aggrecan, biglycan, decorin, and versican). In trigger finger tendons, collagen types 1a1 and 3a1, aggrecan and biglycan were all up-regulated, and MMP-3and TIMP-3 were down-regulated. These changes were statistically significant and have been previously described for Achilles tendinosis. The remaining four genes were not significantly altered. The changes in gene expression support the hypothesis that trigger finger is a form of tendinosis. Because trigger finger is a common condition, often treated surgically, it could provide opportunities for clinical research on tendinosis.

Rupture atypique d’un tendon fléchisseur profond chez un grimpeur

Injuries of the flexor pulleys are common in rock climbers. Ruptures of the flexor profundus tendons are less common and take place almost exclusively in zone I at the level of the distal phalangeal insertion of the tendon. We report the case of a 48years old rock climber who sustained an uncommon complete rupture of the flexor profundus tendon of the long finger during a monodigital grip. The tear was localized in zone III, immediately distal to the distal edge of the carpal tunnel. Tendon repair by direct suture followed by early active mobilization led to a satisfactory result. To the best of our knowledge, this is the first description of this type of injury in a rock climber.

Two-Staged Tendon Reconstruction in Flexor Tendon Ruptures Secondary to Fracture of the Hamate Hook

We report a case of 2-staged reconstruction of flexor tendons ruptured spontaneously by attrition. A 49-year-old man presented with inability to flex the ring and little fingers of his left hand. Preoperative computed tomographic scans revealed fracture of the hamate hook. At the time of the operation, both the flexor superficialis and profundus of the little finger and the flexor profundus tendon of the ring finger were ruptured adjacent to the fracture site of the hamate. Because the flexor tendon rupture secondary to the fracture of the hamate is extremely rare, and surgical outcomes of previous reports are not satisfactory, a decision was made to perform 2-staged reconstruction of ruptured flexor tendons. The surgical result was excellent with complete restoration of full range of motion. This report describes for the first time to our knowledge, the technique, and rehabilitation of 2-staged tendon reconstruction in a patient with hook of hamate fracture.

A Unique Variation of Flexor Digitorum Superficialis Muscle and Its Clinical Significance

KEYWORDS Additional Flexor Muscles. Flexor Digitorum Superficialis Indicis. Gantzer 's Muscle. Carpal Tunnel Syndrome ABSTRACT A wide array of supernumerary and accessory musculature of forearm has been described in the anatomical, surgical and radiological literature. In majority of the cases, these accessory muscles are asymptomatic but in some cases, these accessory muscles produce clinical symptoms. They may be present as a palpable soft swelling or as a fibro-osseous mass near carpal tunnel with symptoms of neurovascular compression. In symptomatic cases, recognition and careful evaluation of accessory muscle with electromyographic examination may aid in diagnosis and in finalizing the treatment. We report a rare case of accessory muscle bellies arising from Flexor Digitorum Superficialis (FDS) muscle on right and left sides. During routine dissections of the forearm performed by preclinical students in the department of anatomy , we observed an accessory muscle belly arising from the tendon of index finger of flexor digitorum superficialis muscle on the right and left sides of a cadaver . The accessory muscle belly has taken its origin at the junction of upper two third and lower one third of forearm and traversed in the carpal tunnel and merged with the tendon of FDS to the index finger in the hand at the level of origin of first lumbrical. Although many anatomical variations of FDS 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.