Congenital flexion deformity of the long, ring, and little fingers with an aberrant origin of the flexor digitorum profundus: case report

A case of congenital flexion deformity of the long, ring, and little fingers with an aberrant origin of the flexor digitorum profundus is described. The aberrant tendinous band originated from a bone prominence in the medial and anterior aspect of the proximal side of the ulna, which was confirmed in the operation. Resection of the aberrant origin could achieve only partial relief for the flexion contracture of the 3 fingers. Further muscle-sliding procedure was needed to achieve a thorough release.     

Ultrasound assessment of the motion patterns of human flexor digitorum superficialis and profundus tendons with speckle tracking

The purposes of our study were to correlate ultrasonographically measured and joint angle estimated excursions of the flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) tendons of the hand and to estimate the relative motion of FDS and FDP while gripping cylinders of standard diameter in normal human subjects. Thirty wrists from 15 human subjects were imaged with an ultrasound scanner. Speckle tracking was used to measure the excursion of the FDS and FDP tendons. The tendon excursions necessary to grip three differently sized acrylic tubes were measured and correlated with the corresponding finger joint angles. The FDP/FDS excursion ratio was calculated. The Pearson's correlation coefficient between the FDS excursion and MP + PIP joint angle was 0.61. The Pearson's correlation coefficient between the FDP + FDS excursion and the DIP + PIP + MP joint angle was 0.67. The FDP/FDS excursion ratio was smaller for larger excursions (gripping a smaller diameter tube) and larger for small excursions (gripping a larger diameter tube, P < 0.01). These data suggest that speckle tracking may be a useful method to discriminate the relative motion of flexor tendons, which in turn may be relevant in evaluating tendon function, for example after tendon injury. © 2011 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 29: 1465–1469, 2011     

Closed rupture of both flexor digitorum profundus and superficialis tendons of the small finger in zone II: case report

We report a rare case of closed rupture of both flexor digitorum profundus (FDP) and flexor digitorum superficialis tendons in zone II in the small finger. We performed delayed, primary end-to-end suture of the FDP and excision of the flexor digitorum superficialis, because myostatic contracture of the FDP tendon was not severe and the FDP tendon remnants were not frayed.     

Spontaneous flexor tendon rupture of the flexor digitorum profundus secondary to an anatomic variant

We report a case of the flexor digitorum profundus tendon rupture of the little finger, which was predisposed by an anatomic variation of the tendon. Intraoperative findings and magnetic resonance imaging of the opposite hand suggested that the flexor digitorum profundus tendons of the ring and the little finger bifurcated. The patient had tendon reconstruction and regained function. We believe that reconstructing the tendon so that it resembles the normal anatomy prevents the recurrence of tendon rupture.     

Zone I rupture of the flexor digitorum profundus tendon caused by blunt trauma: a case report

Traumatic ruptures of flexor tendons as a result of blunt trauma without an associated pathologic condition are rare. This is a case of a midsubstance flexor tendon rupture as a result of closed direct trauma. The patient sustained a flexor digitorum profundus (FDP) rupture 1 cm proximal to its insertion on his right ring finger without any accompanying laceration. Additionally, this case highlights the utility of ultrasound in diagnosing ruptured flexor tendon, which has been demonstrated in prior studies.     

Spontaneous flexor tendon ruptures of the hand: case series and review of the literature

Spontaneous flexor tendon ruptures within the hand are incompletely understood. We report 5 cases of spontaneous tendon rupture involving the flexor digitorum profundus tendon. One case involves an abnormal intertendinous connection between the ring and small finger profundus tendons and another involves a lumbrical muscle variant. To our knowledge, the latter has not been reported in association with spontaneous tendon rupture. In reviewing the literature for spontaneous flexor tendon ruptures, a total of 50 spontaneous ruptures in 43 cases was found. The majority involve the profundus tendon of the small finger in the palm. The ruptures most often occur during periods of peak strain but can also occur without identifiable trauma. The pathogenesis of spontaneous tendon ruptures is still unclear and is likely multifactorial. Spontaneous flexor tendon ruptures of the hand occur more often than one might recognize.     

A rare presentation of flexor digitorum profundus type V avulsion injury with associated intra-articular fracture: A case report

Traumatic avulsions of the flexor digitorum profundus tendon are associated with young adults engaged in athletic activities such as football and rugby. The current report presents a case involving a 30-year-old man with traumatic avulsion of his flexor digitorum profundus and associated intra-articular distal phalangeal fracture secondary to injury during martial arts – an unusual cause of this injury. Increased attention to injuries acquired during this form of sporting activity is suggested.     

Biomechanical influence of the vincula tendinum on digital motion after isolated flexor tendon injury: a cadaveric study

PURPOSE: The vincula are specialized mesotendinous structures attaching to the flexor tendons of the hand. In addition to providing vascular supply to the tendons, the vincula can be mechanically important. The purpose of this study was to quantify the influence of intact vincula on digital flexion after flexor tendon laceration and to assess the ultimate strength and stiffness of the vincula. METHODS: The index, middle, and ring fingers of 12 fresh-frozen cadaveric fingers were dissected free at the level of the metacarpophalangeal joint, preserving at least 10 cm of the flexor and extensor tendons. A 9.8-N load was applied to each flexor tendon, and using digital photography and image analysis software, the degree of flexion at the proximal and distal interphalangeal joints and excursion of tendons proximal to the metacarpophalangeal joint was recorded before and after division of the flexor digitorum profundus and flexor digitorum superficialis tendons at their insertions. Load to failure and stiffness of the vincula were measured via a uniaxial material testing apparatus. Analysis of means was performed with a paired t-test. RESULTS: After division of the flexor digitorum superficialis tendon, proximal interphalangeal joint flexion secondary to the influence of the intact vincula was 93% of that compared with the uninjured digit. Distal interphalangeal joint flexion after flexor digitorum profundus transection was 69% of normal. The increased excursion of transected tendons compared with testing before division was 4 mm for flexor digitorum superficialis and 2 mm for flexor digitorum profundus. Load to failure was 27 N, and stiffness was 6 N/mm. CONCLUSIONS: The vincula breve can facilitate digital flexion after distal tendon transection, allowing tendons to act indirectly across the interphalangeal joints. The intact vincula breve can facilitate an almost normal range of motion across the interphalangeal joints, making the diagnosis of a flexor tendon injury difficult. In the immediate postinjury period, the vincula breve can hold a divided tendon within a few millimeters of its insertion. Testing against resistance is important to avoid missing the diagnosis of a tendon injury.     

Congenital shortening of the flexor digitorum profundus muscle

An 8-year-old boy with a history of the inability to extend the middle finger at the proximal interphalangeal and distal interphalangeal joints with the wrist and metacarpophalangeal joints in the neutral position since the age of 5 months had surgery. The flexor digitorum profundus muscle of the middle finger had a short muscle belly and was replaced in part with mature fat tissue. Histologic examination of the resected tissue showed replacement of a part of the muscle with mature fat tissue. It was speculated that some myosatellite cells, which typically differentiate into skeletal muscle cells, may have erroneously differentiated into adipocytes in the first postnatal year, during which complete development of skeletal muscles occurs.     

A case of trigger finger following partial laceration of flexor digitorum superficialis and review of the literature

Trigger finger is a common condition, and the usual cause is stenosing tenosynovitis. Trigger finger caused by trauma is extremely rare. We examined a patient in whom an apparently trivial laceration caused partial laceration of the flexor tendon, leading to trigger finger. In this case, ultrasonography was useful in establishing the presurgical diagnosis. Removal of the impinging tag cured the trigger finger. We also review nine previously reported cases. When triggering occurs after an injury near the base of a finger, partial laceration of the flexor tendon should be kept in mind as the cause. Ultrasonography may be valuable for the diagnosis.     

Suturing of the flexor digitorum profundus tendon to the entire volar plate in distal zone I injuries

Purpose: The author conducted an anatomical and a prospective clinical study to address the technique and complications of using the entire volar plate (VP) as a distally-based flap for distal Zone I flexor digitorum profundus (FDP) tendon repair. Methods: In the anatomical study, eight fresh finger specimens were dissected to study the anatomy of the VP as well as the stability of the distal interphalangeal joint (DIPJ) after raising the entire VP as a distally-based flap. In the clinical series, six patients underwent repair of distal Zone I FDP lacerations using the VP flap technique and were assessed at a mean of 9 months for range of motion as well as DIPJ deformities. Results: The results of the anatomical study showed that the intact collateral ligaments can still maintain the stability of the DIPJ after loss of joint support from the VP. In the clinical series, none of the patients showed joint hyper-extension or flexion contracture at the DIPJ. Using Moiemen-Elliot criteria, the post-operative active range of motion at the DIPJ was rated as excellent in one, good in three, and fair in two patients. Conclusion: It was concluded that the use of the entire VP as a distally based flap is an acceptable technique to repair distal FDP injuries and the technique does not result in DIPJ instability or flexion contracture.     

Biomechanical evaluation of flexor tendon graft with different repair techniques and graft surface modification

The purpose of this study was to investigate the biomechanical properties of modified repair techniques for flexor tendon reconstruction and the effects of surface modification using carbodiimide‐derivatized synovial fluid plus gelatin (cd‐SF‐G), compared to the traditional repair techniques. The second and fifth digits from 16 canine forepaws were randomly divided into 4 groups: (1) traditional graft repairs (TGR group) including distal Bunnell repair and proximal Pulvertaft weave repair; (2) modified graft repairs (MGR group) including distal graft bony attachment repair and proximal step‐cut repair; (3) group TGR coated with cd‐SF‐G (TGR‐C group); and (4) group MGR coated with cd‐SF‐G (MGR‐C group). Digit normalized work of flexion (nWOF), ultimate failure strength, and stiffness were measured. The nWOF in MGR group was significantly less than TGR group (p < 0.05). The nWOF in groups treated with cd‐SF‐G was significantly less than their untreated counterparts (p < 0.05). Ultimate load to failure of the MGR‐C group was significantly greater than the TGR‐C group (p < 0.05), but no significant difference in stiffness was found between these two groups. The modified techniques cannot only improve tendon gliding abilities but can also improve breaking strength. Additionally, surface modification with cd‐SF‐G significantly decreased the work of flexion. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:731–737, 2015.