Accessory Ligament Research Articles

Singularities of digital flexor tendons in the Catalan Pyrenean Horse

The gross anatomy of the digital flexors tendons and the distal accessory ligament of the Catalan Pyrenean Horse, an equine trait breed from Catalonia (NE Spain), is presented here. Research has been based on the dissection of isolated 10 right forelimbs, 10 left forelimbs, six right hindlimbs and five left hindlimbs (total 31 distal limbs) from clinically normal yearlings, about 12 months of age. Tendons dimensions tended to be bigger than those reported in the literature, probably due to breed, age, bodyweight, withers height and exercise programme. Distal accessory ligament was sometimes absent. Data intend to serve as standard manual data for this breed but also for other trait breeds, being the present study the first one on the subject.

Acoustic Radiation Force Impulse (ARFI) elastography imaging of equine distal forelimb flexor structures

ABSTRACT This study set out to determine normal values for acoustic radiation force impulse (ARFI) elastography of the superficial digital flexor tendon, deep digital flexor tendon, accessory ligament of the deep digital flexor tendon and suspensory ligament in horses. Twenty-four horses were submitted to conventional sonographic assessment and elastography imaging (quantitative ARFI method) of distal forelimb tendons and ligaments at nine anatomical regions. Elastograms depicted tendons and ligaments in orange to red tones consistent with greater stiffness. Shear wave velocity was higher in the longitudinal compared to the cross-sectional plane but did not differ significantly between the left and right forelimbs. The suspensory ligament was stiffer compared to remaining structures in the cross-sectional plane. Ligaments were stiffer than tendons and the deep digital flexor tendon was stiffer than the superficial digital flexor tendon in the longitudinal plane. Target structures were stiffer in male compared to female horses and stiffness tended to increase with age. ARFI elastography proved to be a feasible and reproducible imaging modality for assessment of distal forelimb tendons and ligaments in horses. Qualitative features derived from stiffness quantification in these structures can be applied to horses with musculoskeletal disorders, as well as to other animal species.

ANOMALOUS PERITONEAL FOLDS OF LIVER WITH INCOMPLETE FISSURE FOR IGAMENTUM TERES - A CASE REPORT

Liver is the largest organ in the human body occupying right hypochondrium, epigastrium and left hypochondrium. The organ develops in the ventral mesogastrium dividing the latter into a cranial part which forms the falciform ligament and lesser omentum and the caudal part which normally degenerates but may persist occasionally in the form of accessory fissures, ligaments and folds. The present case report describes the occurrence of exceptional and multiple abnormal peritoneal ligaments extending between the liver, diaphragm and abdominal wall. In concurrence, an incomplete fissure for ligamentum teres hepatis is reported which resulted in a communication between the left lobe and quadrate lobe of liver. The knowledge of the normal and the variant anatomy of such peritoneal reflections of liver is of colossal significance for surgeons performing the segmental resection of the liver and radiologists interpreting radiological findings related to liver.

SDFT reinjury: desmotomy versus chemical counterritation

The purpose of this study is to compare clinical results in horses with a reinjury of the superficial digital flexor tendon (SDF) treated with desmotomy of the accessory ligament of SDF or with “counterirritation” through a blister ointment. Horses have been divided into two groups: Group 1-horses treated with surgery; Group 2 horses treated with the application of a blister ointment. The results have shown in Group 1 one horses had a recurrent injury to the SDF after the second competition, instead in Group 2 one horse had a recurrent injury to the SDF after the third competition, one after the first and one after the second. In the present study no statistically significant differences (P=0,058) were detected between the two groups in terms of performance and reinjury incidence for about five competitions.

Kinematics of Thumb Ulnar Collateral Ligament Repair With Suture Tape Augmentation

Acute thumb ulnar collateral ligament (UCL) tears are common injuries of the thumb in athletes. Thumb UCL repair with suture tape augmentation is a novel procedure that may allow earlier return to play. The purpose of this study was to evaluate the biomechanical characteristics of the thumb after UCL repair with and without suture tape augmentation. Eight cadaveric thumbs were tested in a custom hand testing system. Varus-valgus kinematics were measured at -10°, 0°, 15°, and 30° of thumb metacarpophalangealflexion under the following conditions: (1) intact thumb UCL, (2) complete UCL tear (proper and accessory ligaments), (3) UCL repair, and (4) UCL repair with suture tape augmentation. Angular stiffness was also quantified after application of sequentially increasing valgus torque in the intact UCL repair and the UCL repair with suture tape augmentation conditions. Complete UCL tear increased total varus-valgus angulation at all degrees of thumb metacarpophalangeal flexion. Thumb UCL repair alone and repair with suture tape augmentation decreased total varus-valgus angulation relative to complete UCL tear at all flexion angles. Total varus-valgus angulation was not significantly different from intact results for either the repair alone or the repair with suture tape augmentation at all flexion angles. Repair with suture tape augmentation had significantly higher valgus angular stiffness compared with repair alone but not compared with intact. Thumb UCL repair with suture tape augmentation is able to restore varus-valgus kinematics after complete UCL tear without over-constraining the joint. In addition, the higher angular stiffness afforded by the suture tape augmentation may allow for earlier rehabilitation after surgery. Thumb UCL repair with suture tape augmentation may allow earlier return to sport in athletes than with repair alone.

The Use of the Water Treadmill for the Rehabilitation of Musculoskeletal Injuries in the Sport Horse.

In recent years, exercise on a water treadmill has come to have great relevance in rehabilitation and training centres for sport horses. Its use exploits certain physical properties of water, related to the fundamental principles of hydrodynamics, such as buoyancy, viscosity, hydrostatic pressure, and water temperature. These properties together with deliberate specification of the depth of the water and the velocity of the treadmill provide a combination of parameters that can be varied according to the purpose of the rehabilitation or training programme, the disease to rehabilitate, or the healing phase. In the current article, kinematic adaptations to exercise on a water treadmill and the direct application of such exercise to the rehabilitation of superficial and deep digital flexor tendon and accessory ligament injuries and back and joint diseases are described.

Biomechanical Analysis of Thumb Ulnar Collateral Ligament Tear Kinematics.

Background: Thumb ulnar collateral ligament (UCL) injuries are common, but the kinematics of these injuries have not been comprehensively described, especially regarding kinematic changes with progressive UCL injury. Methods: Eleven cadaveric thumbs underwent kinematic testing under 4 conditions: intact, partial tear (50%) of the proper UCL, full tear of the proper UCL, and complete tear of both the proper and accessory UCL. Kinematic testing parameters included varus/valgus stress, pronation/supination, and volar/dorsal translation at -10 degree, 0 degree, 15 degree, and 30 degree of metacarpophalangeal flexion. Results: Partial tear of the proper UCL did not result in significant increases in laxity in any direction compared with intact (P ≥ .132). Full tear of the proper UCL resulted in a significant increase in valgus angulation (18.8° ± 1.7° vs 11.5° ± 1.5°; P = .024) and pronation (15.4° ± 2.5° vs 12.6° ± 2.3°; P = .034) at 30 degree of flexion relative to intact. Complete tear of both the proper and accessory collateral ligaments resulted in increased valgus angulation at all degrees of flexion (P < .001). Complete tear also resulted in a significant volar translation at 0 degree, 15 degree, and 30 degree of flexion (P ≤ .016). Conclusion: Partial tear of the proper UCL does not significantly affect the stability of the joint, but full tear of the proper UCL increases valgus instability at 30 degree of flexion. Complete tear of the UCL is necessary for increased varus/valgus instability at all degrees of flexion and results in significant increases in pronation/supination and volar translation.

The Accessory Iliotibial Band-Meniscal Ligament of the Knee: Association With Lesions of the Lateral Meniscus.

OBJECTIVE. The anchoring of the medial meniscus is consistent, whereas the attachment of the lateral meniscus is variable. On routine MRI examinations, we analyzed the prevalence of a distinct fibrous connection between the anterolateral aspect of the lateral meniscus and the iliotibial band-which we have termed the "accessory iliotibial band-meniscal ligament" or "AIML"-and investigated an association between lesions of the lateral meniscus and the presence of an AIML. MATERIALS AND METHODS. We retrospectively reviewed 1019 knee MRI examinations for lesions of the lateral meniscus, presence and morphology of an AIML, and Hoffa edema. Descriptive statistics were applied and univariate analyses were performed to assess the association between the presence of an AIML and meniscal lesions as well as Hoffa edema. RESULTS. An AIML was present, with a mean length of 22.8 mm (range, 12.9-36.8 mm; SD, 5.8 mm), in 13.3% of the patients (136/1019). A lesion of the anterior horn of the lateral meniscus was recorded in 1.2% of patients without an AIML (11/883) and 23.5% of patients with an AIML (32/136; p < 0.001). A lesion of the lateral meniscus body was found in 1.6% of patients without an AIML (n = 14/883) and 16.2% of patients with an AIML (22/136, p < 0.001). Hoffa edema was seen in 0.2% of patients without an AIML (2/883) and 14.0% of patients with an AIML (19/136; p < 0.001). CONCLUSION. The AIML represents an anatomic variant of fixation of the lateral meniscus that is strongly associated with lesions of the lateral meniscus and Hoffa edema.

Anatomical study on the attachment location of forearm interosseous membrane ligament

Objective To elucidate the composition and precise attachment location of the forearm interosseous membrane ligament complex. Methods Thirty-two adult cadaveric forearm specimens were dissected to identify all ligaments of the interosseous membrane, measure the distance between the attachment site and the radius styloid process or the tip of the ulna head, and express the attachment location of the ligament by the percentage of the length to the length of the whole ulna and radius. Results The forearm interosseous membrane consists of five ligament components: central ligament, accessory ligament, distal oblique tract, proximal oblique cord and dorsal accessory oblique cord. The distal and proximal positions of the radius origin of the central ligament were 55% and 66% of the total radius length, respectively, and 30% and 42% of the total ulna length. The central points of the radius and ulna attachment location were 38% of the radius and 24% of the ulna for the accessory ligament, 10% of the radius and 16% of the ulna for the distal oblique tract, 78% of the radius and 82% of the ulna for the proximal oblique cord, and 63% of the radius and 65% of the ulna for the dorsal accessory oblique cord. Conclusion This study elucidates the precise attachment location of all the typical forearm interosseous membrane ligaments. This information is very useful for the biomechanical study of the interosseous membrane ligaments and the appropriate transplantation location of the interosseous membrane reconstruction surgery. Key words: Forearm; Anatomy; Interosseous membrane; Ligaments; Attachment location

Sexual dimorphism in the anatomy of the ulnar collateral thumb ligament.

Treatment of ruptured ulnar collateral thumb metacarpophalangeal (MCP) joint ligaments (UCL) necessitate aprofound anatomic knowledge for optimal surgical repair in order to preserve range of motion and ensure postoperative joint stability. Therefore, knowledge of the angle between the UCL and the longitudinal axis of the first metacarpal bone could be useful. In this study 46 ulnar collateral thumb MCP joint ligaments in 15male and 15female embalmed anatomic specimens were dissected and the angles between the longitudinal axis of the first metacarpal bone and the proper (PUCL) as well as the accessory ulnar collateral thumb MCP ligament (AUCL) were measured. In male specimens the angle for the PUCL measured on average 133.5° (±2.35°) and 122.75° (±3.8°) for the AUCL. Asignificantly different angle was measured for female specimens which showed on average 137.88° (±3.51°) for the PUCL and 128.65° (±4.14°) for the AUCL. Optimal surgical repair or reconstruction of torn ulnar collateral thumb MCP joint ligaments should aim for an angle of approximately 135° in PUCL and 126° in AUCL in relation to the longitudinal axis of the metacarpal bone. Differences in men and women should be considered if possible. IV(anatomic study).

Bilateral Locking of the Metacarpophalangeal Joint

The purposes of this article were to present an exemplary case of bilateral locked metacarpophalangeal (MCP) joint of the second metacarpal and to review the literature for a more comprehensive understanding of this condition. For the literature review, PubMed and Google Scholar research were performed using the term "metacarpophalangeal joint (MCP joint) locking or locked metacarpophalangeal joint (MCP Joint)" with a set of inclusion and exclusion criteria. We recently treated a patient with bilateral locked MCP, which presented to our office on 2 separate occasions in the space of 3 years. The left hand was affected in 2015 and the right hand in 2018. After clinical and imaging investigations, the patient was operated on. The patient had a locking of the accessory collateral ligament behind a radial sided prominence of the second metacarpal head. After surgery, the patient regained full function of her index finger. On the basis of our literature review, we found 47 cases described in the literature, plus our case, the index finger (22), and the long finger (11) were most commonly involved. Left untreated, the locked MCP joint may lead to a flexion contracture and disabilities in performing daily life activities. The diagnosis is mainly clinical. The radiographs can show degenerative changes or a particular shape of the metacarpal head/neck as a first clue to the possible cause. Gentle closed reduction can be attempted, but surgery is most often required. The surgical approach depends on the presumed localization of the pathology.

Introducing the craniocervical Y-ligament.

We examined the accessory atlantoaxial ligaments and found them to be a part of a complex ligamentous structure, which we named craniocervical Y-ligament with respect to its shape. The ligaments of the upper cervical spine were dissected in ten Thiel embalmed human cadavers. Origin and attachment of the Y-ligament were described and a detailed photo and video-documentation was carried out with the head in the neutral position, flexion, extension and rotation to study the ligament during these movements. The Y-ligaments were found to be paired and symmetric in all specimens. The shape of the ligament is similar to an Y, its lateral arm connecting the atlas to the axis, its medial arm connecting the occipital bone to the axis, fusing with the two main ligaments, the alar and transverse ligaments. The lateral arm of the Y-ligament was found to be analogous to the accessory atlantoaxial ligament. During cervical flexion, both arms of the Y-ligament became taut while extension made the Y-ligaments relaxed. During rotation both Y-ligaments became taut, moving in the opposite directions in the sagittal plane while following the gliding movements of the lateral masses of the atlas. The craniocervical Y-ligament is a complex ligamentous structure and has a constant anatomy. Because of its shape and special arrangement, it probably plays a role in limiting both atlantooccipital and atlantoaxial movements. Acknowledgement of this ligamentous structure will help understand upper cervical stability. The present study should serve as a basis for future biomechanical and radiological studies.

Comparison of ultrasonographic imaging of the accessory ligament of the deep digital flexor tendon from the lateral and palmar aspects of the metacarpus

Comparison of ultrasonographic imaging of the accessory ligament of the deep digital flexor tendon from the lateral and palmar aspects of the metacarpus

Effect of McGlamry Elevator Placement on the Plantar Plate Origin

Category: Lesser Toes Introduction/Purpose: Lesser metatarsal phalangeal (MTP) joint plantar plate tears have been implicated in a variety of lesser toe pathologies, and plantar plate repair (PPR) through a dorsal approach has become increasingly popular as a treatment of lesser toe deformities and lesser MTP instability. With the aid of a McGlamry elevator, releasing the collateral ligaments and micro-suture passing techniques, the plantar plate is repaired under direct visualization. While this approach is seen as a reliable alternative, the consequence of this technique on local MTP joint anatomy is not yet well understood. The purpose of this study is to describe the proximal plantar plate attachment and to quantify the amount of soft tissue disruption of the lesser toe MTP joint anatomy with insertion of a McGlamry elevator. Methods: Fresh frozen human cadaveric feet were dissected, and the proximal plantar plate attachment of the second, third, and fourth toe MTP joints (n=6) were examined, focusing on the relationship of structures connecting the distal metatarsal shaft and head to the plantar plate. The accessory collateral ligament insertions and proximal plantar plate attachments were measured using digital calipers. Next, the second, third, and fourth rays (n=12) of separate fresh frozen cadaveric specimens were isolated. An 11mm McGlamry elevator was then inserted in standard surgical fashion in both a more shallow (limited exposure) and deeper (greater exposure) position. Using mini C-arm fluoroscopy, radiographs were taken in both positions, and the depth of insertion along the metatarsal was measured. Results: The proximal plantar plate attachment to the metatarsal is most robust just proximal to the lateral articular margin and this attachment extends an average of 10.42mm (SD= 2.71mm) proximally along the metatarsal neck and shaft. In addition there are stout proximal plantar plate attachments at the bilateral insertion sites of the accessory collateral ligament (ACL) which are thick and broad with an average insertion length of 9.01mm (SD=1.35mm). Insertion of a McGlamry elevator resulted in stripping of the distal plantar soft tissues over an average of 21.58% of the total metatarsal length (SD=4.43%) for shallow placement and 34.87% (SD=4.40%) for deep placement with a significant difference of 7.96% between the two positions (p&lt;.00001). Conclusion: Current techniques of plantar plate repair through a dorsal approach require releasing collateral ligaments and proximal stripping of the plantar plate from the metatarsal for adequate visualization. We suggest that this significantly destabilizes the metatarsal from the plantar plate as it strips approximately the distal most one third of the metatarsal including all major proximal plantar plate attachments to the metatarsal. As surgical techniques continue to evolve and improve, surgeons should consider avoiding the placement of a McGlamry elevator as this can destabilize the proximal attachment of the plantar plate to the metatarsal.

An RNAi Screen Identifies New Genes Required for Normal Morphogenesis of Larval Chordotonal Organs.

The proprioceptive chordotonal organs (ChO) of a fly larva respond to mechanical stimuli generated by muscle contractions and consequent deformations of the cuticle. The ability of the ChO to sense the relative displacement of its epidermal attachment sites likely depends on the correct mechanical properties of the accessory (cap and ligament) and attachment cells that connect the sensory unit (neuron and scolopale cell) to the cuticle. The genetic programs dictating the development of ChO cells with unique morphologies and mechanical properties are largely unknown. Here we describe an RNAi screen that focused on the ChO’s accessory and attachment cells and was performed in 2nd instar larvae to allow for phenotypic analysis of ChOs that had already experienced mechanical stresses during larval growth. Nearly one thousand strains carrying RNAi constructs targeting more than 500 candidate genes were screened for their effects on ChO morphogenesis. The screen identified 31 candidate genes whose knockdown within the ChO lineage disrupted various aspects of cell fate determination, cell differentiation, cellular morphogenesis and cell-cell attachment. Most interestingly, one phenotypic group consisted of genes that affected the response of specific ChO cell types to developmental organ stretching, leading to abnormal pattern of cell elongation. The ‘cell elongation’ group included the transcription factors Delilah and Stripe, implicating them for the first time in regulating the response of ChO cells to developmental stretching forces. Other genes found to affect the pattern of ChO cell elongation, such as αTub85E, β1Tub56D, Tbce, CCT8, mys, Rac1 and shot, represent putative effectors that link between cell-fate determinants and the realization of cell-specific mechanical properties.

The annular ligament—revisited

Studies investigating the annular ligament have presented confusing information about its anatomy and nomenclature. Cadaver elbow dissections were used to clarify the anatomy and terminology of the annular ligament. Nineteen elbows were dissected (7 fresh frozen and 12 embalmed). Target structures were identified, photographed, and measured by independent observers. There are 3 layers to the lateral elbow ligaments: the superficial lateral ulnar collateral and radial collateral ligament; a deeper layer of the superior oblique band (SOB) and inferior oblique band (IOB) of the annular ligament; and the deepest capsular layer. The annular ligament measured 9.5 ± 1.4 mm anteriorly. The SOB (15/19) was 3.9 ± 1.0 mm wide by 10.5 ± 3.8 mm long. The IOB (13/19) was 3.6 ± 1.1 mm wide by 11.4 ± 4.2 mm long. The IOB inserts onto the anterior proximal ulna rather than the supinator crest. The anterior oblique band (8/19) was 3.8 ± 1.7 mm wide. The SOB and IOB were present in the majority of specimens. The previously described accessory lateral collateral ligament is a localized thickening on the lateral ligament complex arising from the supinator insertion independent of the IOB that attaches to the annular ligament inferiorly and distally and attaches onto the proximal anterior ulna at the bicipital fossa floor, medial to the supinator crest.

Retrospective analysis of distal limb conformation and lameness in mature horses after desmotomy of the accessory ligament of the deep digital flexor tendon for management of a flexural deformity

SummaryMature horses that present with flexural deformity of the distal interphalangeal joint and lameness isolated to the foot may obtain long‐term benefits from desmotomy of the accessory ligament of the deep digital flexor tendon (ALDDFT). This retrospective analysis of medical records and radiographs included 13 horses, aged ≥2 years, presented for lameness isolated to the hoof region and diagnosed with flexural deformity of the distal interphalangeal joint. Radiographic angles of the hoof and distal interphalangeal joint and lameness scores were compared before and after desmotomy of the ALDDFT. Follow‐up data including the ability to perform the intended use were obtained at least one year after surgery. There was improvement in the angle between the dorsal aspect of the third phalanx and the weightbearing surface of the hoof, improved alignment between the dorsal hoof wall and dorsal aspect of the third phalanx, and improved alignment of the distal interphalangeal joint. Lameness was decreased in 9/13 horses and 10/13 horses were performing at their level of intended use. Evidence of improved hoof conformation and lameness following desmotomy of the ALDDFT in lame horses with flexural deformity of the distal interphalangeal joint would indicate this procedure should be considered in mature horses.

Anatomical transverse magnetic resonance imaging study of ligaments in palmar surface of metacarpus in Miniature donkey: identification of a new ligament.

Palmar region of metacarpus in the horses and donkeys is an important region because of its tendons and ligaments which contribute to stay apparatus. This study was done on forelimbs of 6 healthy Miniature donkeys to detect the tendons, ligaments and their accessories on the palmar surface of metacarpus in this animal. Based on that magnetic resonance imaging (MRI) is a good technique to evaluate the soft tissues such as tendons and ligaments, palmar aspects of metacarpus in 6 euthanatised Miniature donkeys were prepared for anatomical and trans-sectional MRI studies to determine the tendons and ligaments in this region. Suspensory ligament, deep digital flexor tendon and its inferior check ligament were similar to them in the horse. Superficial digital flexor tendon (SDFT) in this animal had superior check ligament that was present before the carpal joint. On the other hand in the Miniature donkey there was a second accessory ligament for the SDFT that originated from the proximal of palmar surface of the large metacarpal bone which we named it second accessory ligament of SDFT. This ligament was determined in the MRI images too. It seems that this ligament helps the Miniature donkey to stay apparatus, supporting more weight and load for a longer period of time and distance which is a specific morphological feature in this animal.

Desmotomy of the accessory ligament of the deep digital flexor tendon for treatment of chronic deep digital flexor tendinopathy in three Quarter Horses

SummaryEffective treatments for horses diagnosed with severe deep digital flexor (DDF) tendinopathy are limited. In this study, three Quarter Horses diagnosed with severe bilateral DDF tendinopathy underwent bilateral desmotomy of the accessory ligament of the DDF tendon after failing to respond to conservative therapy. Lameness markedly improved in all three horses. Given that severe DDF tendinopathy is typically associated with persistent or recurrent lameness, desmotomy of the accessory ligament of the DDF tendon might be a treatment option to alleviate lameness in horses with DDF tendinopathy. This treatment option appears promising; however, a larger number of cases is necessary to support the results in these three horses.

Locked metacarpophalangeal joint of long fingers: Clinical presentation, literature review, and a treatment-oriented classification

Objectives: The purpose of this article was to present two exemplary cases of the disorder known as locked metacarpophalangeal (MCP) joint of long fingers, to review the literature and to recommend the possible surgical approaches based on the involved anatomic structures. Patients and Results: We recently took care of two patients with locked MCP joint representing the two main etiologies of this disorder. After clinical and imaging investigations both patients were operated. The first patient had a locked intra-articular loose body in the third metacarpophalangeal joint, which was undetectable on MRI. The second had a locking of the accessory collateral ligament behind a radial sided prominence of the second metacarpal head. Both had a satisfactory outcome after surgery. Conclusion: Left untreated, the locked MCP joint may lead to a flexion contracture. The diagnosis is mainly clinical. The radiographs can show degenerative changes or a particular shape of the metacarpal head/neck as a first clue to the possible cause. A MRI may help to precise the origin of the locking. Gentle closed reduction can be attempted, but surgery is most often required. The surgical approach depends on the presumed localization of the pathology.