Insertion Of Flexor Digitorum Superficialis Research Articles

What's New in Hand and Wrist Surgery.

What's New in Hand and Wrist Surgery.

Outcomes of single digit replantation for amputation proximal to the flexor digitorum superficialis insertion: A systematic review with meta-analysis.

A single digit amputated proximal to the flexor digitorum superficialis (FDS) insertion is a relative contraindication to replantation. The aim of this study is to conduct a systematic review on replantation of these injuries to synthesize best available evidence on outcomes. This review was registered in PROSPERO under registration number CRD42021277305. A MEDLINE, CENTRAL, and EMBASE databases search yielded 1536 studies. Primary clinical studies on single digit replantation and functional outcome with at least 10 cases were included. Data on revision amputation and replantation distal to the FDS were collected as comparators. Data extracted included demographics, type of digit, level of injury, secondary surgeries, duration of sick leave, survival, function, and patient-reported outcomes. All studies were assessed using the Risk of Bias In Non-randomized Studies of Intervention (ROBINS-I) tool and data synthesis was completed using RevMan and Microsoft Excel. Six studies representing 182 replanted single digits that were amputated proximal to the FDS insertion were included. The average PIPJ motion of replanted single digits was 50° in those amputated proximal to the FDS insertion compared to 82.5 in those amputated distal to the FDS. The average Michigan Hand Questionnaire (MHQ) score was 84.78 in replantation group versus 76.81 in the amputation group which was statistically significant (p< .00001). Mean Disability of Arm, Shoulder, and Hand Questionnaire (DASH) score was 12 in replantation group compared to 18.5 in amputation group, however this was not statistically significant (p= .17). Few studies exist on outcomes of single digit replantations proximal to FDS insertion. Although range of motion is inferior in the replant group, this has increased since initial studies were performed, and patient satisfaction and patient reported outcomes are high. This is promising evidence for achieving reasonable outcomes in replantation of single digits amputated proximal to the FDS. Level III.

Redefining Zone II: Anatomy of the Flexor Digitorum Superficialis Insertion.

Flexor zone II is defined as the region spanning the proximal aspect of the A1 pulley to the insertion of the flexor digitorum superficialis (FDS) tendon. Descriptions of the FDS insertion are inconsistent in the literature, but zones of injury are frequently determined with reference to superficial landmarks. The purpose of this study was to describe the footprint of the FDS insertion and define its relationship to the proximal interphalangeal (PIP) skin crease. The FDS insertion on the index, middle, ring, and small fingers was dissected in 6 matched pairs of fresh-frozen cadaveric hands. A Kirschner wire was used to mark the level of the PIP skin crease on bone before measurements of the FDS footprint and its position relative to the PIP skin crease were made using digital calipers. The radial and ulnar FDS slips inserted a mean distance of 3.22 mm from the distal aspect of the PIP skin crease and varied by digit. The mean distal extent of the FDS insertion was 8.29 mm. The mean length of the insertion of each FDS slip was 5.15 mm and the mean width was 1.9 mm. The radial and ulnar FDS slips insert on average 3.22 mm distal to the PIP skin crease and vary by digit. Knowledge of the FDS insertion is clinically relevant when differentiating between flexor zone I and zone II injuries, planning surgical approaches to the finger, and in guiding patient expectations for surgery given the variability in outcome based on zone of injury.

Acute Calcific Tendinitis of the Flexor Digitorum Superficialis of the Finger: A Case Report

Acute calcific tendinitis of the shoulder is a well-known condition, but it is rare in the hand or finger. It is often misdiagnosed when it occurs outside the shoulder. We report an unusual case of acute calcific tendinitis of the flexor digitorum superficialis insertion of the 4th finger in a young female martial art athlete after minor trauma history, and discuss with a review of the literature.

Surface Markers for Locating the Pulleys and Flexor Tendon Anatomy in the Palm and Fingers With Reference to Minimally Invasive Incisions

Palm and finger pulley anatomy has been well described in relation to osseous structures. The goal of this study was to describe skin surface markers that locate the underlying flexor tendon and pulley system. We describe the anatomic detail of these structures and provide a guide for the surgeon for making small incisions. Using this approach, extensile exposure can be avoided, and the integrity of the complex pulley system is maintained. We dissected 12 palms and 48 fingers in 12 cadaver hands. We marked the palm and finger creases with methylene blue before dissection. We removed palm skin, finger skin, and subcutaneous tissue over the flexor tendon sheath and retained a 2-mm strip of each skin crease in its native position. We divided the palm and palmar surface of the fingers into 4 distinct zones and measured the location of the proximal and distal extent of each pulley and the tendon anatomy relative to the proximal and distal skin crease. We documented the location of the proximal and distal extent of the annular and cruciate pulleys as well as the decussation of the flexor digitorum superficialis (FDS) tendon and Camper chiasm. The results allow us to establish a relationship between the skin creases and underlying anatomy by dividing the palm and finger into 4 zones. In zone A, in the palm, the A2 pulley is located in the distal third and the FDS decussation is at the proximal extent of the A2 pulley. Zone B is in the proximal phalanx and A2 lies in the proximal third of this zone, whereas the Camper chiasm lies in the middle third. Zone C is in the middle phalanx and A4 and the insertion of FDS lie in the middle third of this zone. Zone D lies in the distal phalanx and the flexor digitorum profundus tendon inserts into the middle third of this zone. Skin creases can be used as surface markers to accurately locate the underlying pulley and tendon system and plan for limited incisions. These anatomic descriptions can aid surgeons in preoperative planning and may also help minimize the required exposure for flexor tendon repair and other surgery in the fingers and palm.

Amputation of Finger by Horse Bite With Complete Avulsion of Both Flexor Tendons

Amputation of fingers with tendon avulsion occurs through a traction injury, and most occur through a ring avulsion mechanism. Usually the flexor digitorum profundus is torn out with the amputated finger. Replantation usually is recommended only when the amputation is distal to the flexor digitorum superficialis insertion. Animal bites are relatively common, with a decreasing order of frequency of dogs, cats, and humans. Horse bites are relatively infrequent but are associated with crush injuries and tissue loss when they occur. This article describes a 23-year-old man with amputation of his middle finger at the level of the proximal phalanx after being bitten by a horse. The amputated stump was avulsed with the middle finger flexor digitorum profundus and flexor digitorum superficialis torn from the muscle-tendon junction from approximately the middle of the forearm. The patient had no other injuries, and he was able to move his other 4 fingers with only mild pain. As the amputated digit was not suitable for replantation, the wound was irrigated and debrided. The edges of the phalanx were trimmed, and the edges of the wound were sutured. Tetanus toxoid and rabies vaccine were administered, along with intravenous amoxicillin and clavulanic acid. The patient was discharged from the hospital 2 days later, with no sign of infection of the wound or compartment syndrome of the forearm. This case demonstrates the weakest point in the myotendinous junction and emphasizes the importance of a careful physical examination in patients with a traumatic amputation.

Modified flexor digitorum superficialis slip technique for A4 pulley reconstruction

We describe a variation in the A4 pulley reconstruction technique using one slip of the flexor digitorum superficialis insertion and report the results of a biomechanical analysis of this reconstruction in cadavers. While conserving the distal bony insertion, one slip of flexor digitorum superficialis is transferred over the flexor digitorum profundus tendon and sutured to the contralateral superficialis slip insertion. This creates a new pulley at the base of the original A4 pulley that can be adjusted to accommodate an FDP repair of increased bulk. We found a 57% reduction in excess excursion due to bowstringing when compared with no repair. Furthermore the repairs were sturdy, 94% of specimens maintaining their integrity when a proximally directed force of 50 N was applied.

Assessment and management of amputations distal to the wrist

Hand amputation is a devastating injury which may result in permanent quality-of-life impairment. The goal of treatment is to anatomically restore the amputated limb in order to optimize sensation and range of motion of the injured structures. All cases should be emergently referred to a hand surgeon trained in microsurgery for assessment and management. Generally accepted indications for replantation include amputation at the level of the wrist or mid-palm, thumb or multiple digit amputation and single digit amputation when distal to flexor digitorum superficialis insertion. In addition, replantation should always be attempted for children. Appropriate primary care which includes wrapping the amputated part in saline-soaked gauze, sealing in a plastic bag, and immersing in an ice bath increases the viability of amputated tissue and facilitates replantation. This review explores hand amputation classification, indications for replantation, primary care of the amputated part, surgical replantation techniques, post-operative care, and complications following replantation surgery. Three cases, treated at the Halifax Infirmary, were identified to illustrate the clinical presentation and outcome of patients presenting with multiple digit, thumb, or mid-palm amputation.

Digital Replantation Including Postoperative Care

Digital replantation first became a reality in the 1960s with the advent of microsurgical techniques. Indications for replantation have evolved over the ensuing years and currently include 1) thumb amputations, 2) multiple digit amputations, and 3) amputations in children. Crush and avulsion injuries and amputations of a single digit proximal to the flexor digitorum superficialis insertion remain relative contraindications. Good communication between the replantation center microsurgeon and the referring physician is paramount to achieving appropriate and timely referrals and correct transport of amputated parts. Communication with patients is also important: possible candidates for replantation must be informed of the likely outcomes of replantation and revision amputation procedures, and the different postoperative regimens for each. For patients who choose revision amputation or whose replants do not survive, there are a variety of reconstructive options available, if necessary, such as toe-to-hand transfer. The techniques to perform such elective free tissue transfers have been perfected during the last 30 years largely from experience gained through digital replantation.

The results of treatment of injuries to the flexor tendons

The results of treatment of flexor tendon injuries in 131 patients are reviewed. The results show that good results can be obtained with primary suture carried out in tidy wounds within eight hours of injury and it is justified to carry out primary suture in these conditions. Secondary suture can also give some satisfactory results. In the finger, suture of flexor digitorum profundus only is advised if both tendons are injured between the distal palmar crease and the insertion of flexor digitorum superficialis. Distal to the insertion of flexor digitorum superficialis, primary suture of flexor digitorum profundus is indicated. In the palm both tendons can be sutured. In the wrist both tendons can be sutured unless the point of division is in the carpal tunnel where flexor digitorum profundus only should be repaired and the carpal tunnel left unsutured. At the wrist repair of the flexor digitorum profundus only might be carried out if the suture lines of all the tendons would be so close as to be likely to adhere to one another and prevent independent action of the tendons.

Fossil Hand Bones from Olduvai Gorge

IN Nature of December 17, 1960, Dr. L. S. B. Leakey reported on the discovery of a number of fossil bones of the hand and the foot on a living floor some 20 ft. below the uppermost limit of Bed I, Olduvai. Later (Nature of February 25, 1961), Dr. Leakey reported the discovery of a mandible and two parietal fragments of a juvenile from the same site and associated with a well-defined living floor of an Oldowan culture. Fifteen of the hand bones pertaining to at least two individuals, an adult and a juvenile, have been identified and examined, and are described here. Their allocation is given in Table 1. The middle phalanges (Fig. 1, second row) from the juvenile hand, lacking only their epiphyses, constitute a series II-V from the right hand. They are robust bones, rather more so than phalanges of comparable length of juvenile Gorilla and adult Homo sapiens. They are strongly curved and, palmad, bear well-defined grooves which are situated in the distal half of the bone for the insertion of flexor digitorum superficialis. The adult proximal phalanges (Fig. 1, third row) are also more robust than bones of comparable length in modern man; they are strongly curved both longitudinally and transversely, fusiform in shape and deeply hollowed out on the palmar aspect; sharply defined fibrous flexor sheath ridges extend from the base of the bones to their necks. The terminal phalanges (Fig. 1, top row) which are juvenile, having incompletely fused epiphyses, are characteristically sapiens in form. The terminal phalanx of the thumb is of particular interest; it is stout and broad and bears a deep impression for the insertion of flexor pollicis longus. The carpal bones (Fig. 1, 4th row) are all damaged, but sufficient of their original form remains to determine their structural and functional affinities. The lunate surface of the scaphoid has a rectangular outline; and the tubercle, which is broken off at its root, was probably somewhat elongated, though not as long as in the anthropoid apes. The trapezium has a well-defined saddlesurface but the evidence provided by the other articular surfaces indicates that its 'set' in the carpus was unlike that found in modern man and similar to the condition in Gorilla. The capitate, though badly eroded, is generally more sapiens than apelike. Morphologically, the Olduvai hand bones cannot be closely matched with any known hominoid species living to-day. They bear, however, a greater similarity to juvenile Gorilla and adult H.s. sapiens than to adult Gorilla, Pan or Pongo. This is due largely to the absence in the fossil bones of any features peculiarly characteristic of brachiators. The adult gorilla hand has a number of specializations that are presumably related to its secondarily terrestrial mode of life and its great body-weight; these features, again, are absent from the fossil bone. The juvenile gorilla hand lacks the secondary specializations of the adult, and it is possibly for this reason alone that its bones have affinities with those of the fossil. The fossil bones differ from those of modern man in a number of features: (1) robustness; (2) dorsal curvature of the shafts of the phalanges; (3) distal insertion of the flexor digitorum superficialis; (4) strength of fibrotendinous markings; (5) 'set' of trapezium in the carpus; (6) the form of the scaphoid; (7) the depth of the carpal tunnel. The fossil bones resemble modern man in the following features: (1) presence of broad, stout terminal phalanges on fingers and thumb; (2) form of the distal articular surface of the capitate; (3) ellipsoidal form of metacarpo-phalangeal joint surfaces. TABLE 1