Dorsal Ligament Research Articles

Anatomical study for elucidating the stabilization mechanism in the trapeziometacarpal joint

To determine the pathogenesis of trapeziometacarpal (TMC) joint instability, which leads to osteoarthritis, we investigated the anatomical relationships among the surrounding ligaments, muscles (first dorsal interosseous [FDI] and opponens pollicis [OPP]), and joint capsule. We examined the bone morphology and cortical bone thickening in 25 cadaveric thumbs using micro-computed tomography and performed macroscopic and histological analyses. The dorsal trapezium had a tubercle with cortical bone thickening, corresponding to the attachment of the FDI aponeurosis intermingled with the joint capsule. Radially, the thin joint capsule was observed to underlie the muscular part of the OPP. Therefore, the dorsal ligaments, which have been previously considered static stabilizers, could be interpreted as parts of the capsuloaponeurotic complex consisting of the FDI aponeurosis and joint capsule. In the radial aspect, muscular OPP activation may be essential for TMC joint stabilization. Our findings may contribute to the appropriate management of TMC osteoarthritis.

Novel transforaminal approach allows surgical decompression of an atlantoaxial band in dogs: a cadaveric study and clinical cases.

To describe a novel transforaminal approach for surgical excision of the atlantoaxial (AA) band and examine its feasibility, safety, and mechanical advantages in an ex vivo study and clinical cases. 26 canine cadavers and 2 canine patients with AA bands. The transforaminal approach via the first intervertebral foramen was designed to avoid damaging the dorsal AA ligament (DAAL) and dorsal laminas to maintain joint stability. The cadaveric study started on December 2020 and lasted 3 months. The ligamentum flavum (LF) was removed using a novel approach; then, gross examination was conducted to verify the potential damage to the spinal cord and associated structures and the adequacy of LF removal. Subsequently, the ex vivo tension test of the DAAL was conducted to establish whether the approach induced mechanical damage to the ligaments. Finally, 2 dogs diagnosed with an AA band were surgically treated with the transforaminal approach. In the cadaveric study, postsurgical evaluation verified the subtotal removal of LF without damage to the dura mater. There were no significant differences in the mechanical properties of the DAAL, including the ultimate strength (P = .645) and displacement (P = .855), between the surgical and intact groups during the ex vivo tension test. In clinical cases, clinical signs and neurologic grades improved until the final follow-up. The described surgical procedure using a transforaminal approach appears to sufficiently permit the removal of an AA band while reducing damage to the DAAL and spinal cord. Our study highlights the feasibility of the transforaminal approach.

The Lateral-W Construct: An Anatomical Variant of the Dorsal Wrist Ligaments.

Background The dorsal intercarpal ligament (DIC) is an elegant dorsal stabilizer of the proximal carpal row, including the scaphoid's proximal pole and scapholunate joint. Along with the dorsal radiocarpal (DRC) ligament, it acts as a dorsal radioscaphoid stabilizer, with dynamism due to its ability to modify its length up to threefold by changing the angles between its V-shaped bundle morphology. The DIC ligament consistently originates from the dorsal tubercle of the triquetrum on the ulnar side. It spans transversely, attaching to the dorsal groove of the scaphoid (97-100%), lunate (75-90%), and proximal rim of the trapezium (12.5-50%), and overlapping the lunotriquetral interosseous ligament and the scapholunate interosseous ligament. Together with the DRC, Viegas et al (Viegas SF, Yamaguchi S, Boyd NL, Patterson RM. The dorsal ligaments of the wrist: anatomy, mechanical properties, and function. J Hand Surg Am 1999;24(3):456-468) proposed that this ligament complex should be called the "lateral-V construct." Anatomical Variant The authors present a unique type C variant of the DIC ligament, showing a distinct thick bundle directed at the dorsal aspect of the second metacarpal base that thus creates a "lateral-W construct." This dorsal triquetro-metacarpal 2 (dTqMC2) ligament acts as restraint to the body of the capitate and will provide enhanced stability of the dorsal midcarpal joint by limiting dorsal translation of the capitate in relation to the lunate. Clinical Relevance Our finding may contribute to the increasing knowledge of the dorsal ligament complex and its role in dorsal midcarpal instability, as well as surgical repair techniques.

OUTCOME ANALYSIS OF DISTAL RADIUS FRACTURES TREATED WITH K-WIRES VS CASTING

Background Distal radius fracture has long been treated by closed reduction and casting . Although casting sufces in a proportion of cases, it may fail to maintaining the reduction is usually a problem. Hence, in a majority of cases, with cast satisfactory reduction can lost resulting in a poor anatomical and in some cases functional outcome. Percutaneous K-Wire xation1-3 is a simple way of providing additional stability to immobilization in casting an unstable fracture of distal radius in which acceptable anatomical reduction is obtainable. The technique is simple, minimally invasive and inexpensive. It is much less intrusive than other methods such as external xation. Though it has its own set of complications e.g. pin tract infection, supercial radial neuropathy etc. It still forms an effective tool in the surgical armamentarium for treatment of distal radius fractures. The present study was conducted at the de Methods partment of orthopaedics Andhra medical college/ king George hospital Visakhapatnam between 2020 and 2021.Sixty patients who fullled inclusion criteria were taken up for study n=60. They were randomly divided into two groups with 30 members each belonging to casting and k-wire xation groups. In Results both treatment methods radial length, ulnar variance, radial angulation are restored to near normal but correction of dorsal tilt is not complete. This is because the fact that volar ligaments are stronger on distraction before relatively 'Z' oriented dorsal ligaments. So, on distraction volar cortex is brought out to length before dorsal cortex preventing full correction of dorsal tilt.Cast immobilization alone could not maintain reduction in unstable fractures resulting in poor anatomical outcome.53% patients of cast immobilization had moderate to severe deformity, compared with only 11.76% patients of K wire and casting group having moderate deformity. At the end of 12 weeks, functional outcomes in the studied both types were almost similar with no signicant difference in DASH scores. At the end of the study, we concluded that Conclusion both the techniques of managements K wire xation and casting and closed reduction and casting gives near equal results in terms of functional outcome. Better anatomical reduction and maintenance of reduction can be expected with K wire xation and casting group.

Ligament-Sparing Volar Radiocarpal Arthrotomy During Distal Radius Fracture Repair: Biomechanical Implications on Wrist Stability in a Cadaveric Model

Distal radius (DR) fracture fixation with volar locked plating typically uses indirect fracture reduction without direct visualization of the articular surface in an attempt to preserve the volar radiocarpal ligaments and prevent iatrogenic radiocarpal instability. This study assessed the biomechanical stability after a volar radiocarpal arthrotomy for direct articular visualization for DR fracture repair compared to a standard trans-flexor carpi radialis approach without arthrotomy in a cadaver model. Ten fresh-frozen upper extremity matched-pair cadaveric specimens were tested. For each pair, one limb underwent trans-FCR approach with a volar arthrotomythat partially sectioned the long and short radiolunate ligamentsto visualize the DR articular surface (Group 1). The contralateral limb underwent standard trans-FCR approach without arthrotomy (Group 2).Following capsular repair (Group 1), all specimens (Groups 1 and 2) underwent biomechanical testing, including axial loading (22.2 N, 44.5 N, 89.0 N, 177.9 N), volar translational, and dorsal translation loading (22.2 N, 44.5 N, 89.0 N) to assess carpal stability using both fluoroscopy and motion capture. Ulnar carpal translation was assessed using the Gilula method, measuring radiographic lunate overhang from the ulnar edge of the lunate fossa relative to the full width of the lunate. Dorsal and volar translation were assessed by measuring lunate overhang with respect to the dorsal or volar radial cortex.To simulate fractures with dorsal radiocarpal ligament disruption, the dorsal capsule was sectioned, and the biomechanical comparisons were repeated. Ulnar translation of the lunate remained below 2 mm for both groups in all testing scenarios. No significant differences were identified in ulnar, volar, or dorsal translation with increasing loads between the groups. This volar ligament-sparing radiocarpal arthrotomy did not cause biomechanical radiocarpal instability. This arthrotomy may provide enhanced visualization of the DR articular surface during fracture fixation without causing iatrogenic wrist instability.

Clinical Outcomes of Arthroscopic Ligament-Sparing Dorsal Capsulodesis for Partial Scapholunate Ligament Tear.

Introduction Various wrist arthroscopy techniques can be used in the management of scapholunate ligament (SLL) partial tears but their success has not been proven. Arthroscopic techniques including thermal shrinkage are becoming more popular in the management of partial SLL injuries. We hypothesized that arthroscopic ligament-sparing capsular tightening yields reliable and satisfactory results for the management of partial SLL tears. Methods A prospective cohort study was conducted on adult (age ≥18 years) patients with chronic partial SLL tears. All patients failed a trial of conservative management consisting of scapholunate strengthening exercises. Patients underwent an arthroscopic dorsal capsular tightening of the radiocarpal joint capsule radial to the origin of the dorsal radiocarpal ligament and proximal to the dorsal intercarpal ligament by either thermal shrinkage or dorsal capsule abrasion. Demographic data, radiological outcomes, patient-rated outcome measures and objective measures of wrist range of motion (ROM), and grip and pinch strength were recorded. Postoperative outcome scores were collected at 3, 6, 12, and 24 months. Data are reported as median and interquartile range, and comparisons were drawn between baseline and last follow-up. Clinical outcome data were analyzed using a linear mixed model method, while radiographic outcomes were assessed with nonparametric analysis with p < 0.05 indicating statistical significance. Results Twenty-three wrists (22 patients) underwent SLL treatment by thermal capsular shrinkage (19 wrists) or dorsal capsular abrasion (4 wrists). Median age at surgery was 41 years (range: 32-48) and median follow-up time was 12 months (range: 3-24). Pain significantly decreased from 62 (45-76) to 18 (7-41) and satisfaction significantly increased from 2 (0-24) to 86 (52-92). Patient-Rated Wrist and Hand Evaluation and Quick Disabilities of the Arm, Shoulder, and Hand significantly improved from 68 (38-78) to 34 (13-49) and from 48 (27-55) to 36 (4-58), respectively. Median grip and tip pinch strength significantly increased at final review. Range of movement and lateral pinch strength were satisfactory and maintained. Four patients required further surgery for ongoing pain or reinjury. All were successfully managed with partial wrist fusion or wrist denervation. Conclusion Arthroscopic ligament-sparing dorsal capsular tightening is a safe and effective treatment for partial SLL tears. Dorsal capsular tightening demonstrates good pain relief and patient satisfaction while improving patient-reported outcomes, grip strength, and maintaining ROM. Longer term studies are required to determine the longevity of these results.

Development of a 3D-immunofluorescence analysis for sensory nerve endings in human ligaments

BackgroundThe analysis of ligamentous mechanoreceptors is difficult due to a high amount of unclassifiable mechanoreceptors, which result from incomplete visualization through limited microscopic techniques. New methodThe method was developed using dorsal intercarpal ligaments and dorsal regions of the scapholunate interosseous ligament from human cadaver wrists. Consecutive 70 µm thick cryosections were stained with immunofluorescence markers for protein S100B, neurotrophin receptor p75 (p75), protein gene product 9.5 (PGP 9.5) and 4′,6-diamidino-2-phenylindole (DAPI). 3D images of sensory nerve endings were obtained using a confocal laser scanning microscope. Experimental point spread functions (PSF) were used to deconvolve images. Sensory nerve endings were localised in each section plane and classified according to Freeman and Wyke. Finally, confocal data was visualized as 3D-images. ResultsThe method produced excellent image quality, revealing detailed three-dimensional structures. The created 3D-model of sensory nerve endings could be analyzed in all three dimensions, augmenting visualization of the form and immunoreactive pattern of sensory nerve endings. Deconvolution with experimentally measured PSFs aided in enhancing image quality. Comparison with existing methodsUsing a triple immunofluorescent staining method allows to visualize the structure of sensory nerve endings more precisely than techniques with serial analysis of different monostaining of neural markers. Imaging in three dimensions enhances morphologic details, which are limited in 2D-microscopy. Conclusion3D-triple immunofluorescence produces high quality visualization of mechanoreceptors, thereby improving their analysis. As an elaborate technique, it is ideal for defined research questions concerning the microstructure of sensory nerve endings.

Reliability of Weight-Bearing Ultrasonography for Diagnosis of Lisfranc Joint Injuries: A Cadaveric Study

Category: Trauma Introduction/Purpose: Ultrasonography is increasingly used to evaluate the stability of various joint in the field of foot and ankle. This study aims to assess and compare the Lisfranc joint stability under stimulated weight bearing condition among progressive stages of Lisfranc ligamentous complex injuries. All the measurements were assessed using ultrasonography, fluoroscopy, and direct open measurement. We hypothesize that there is a correlation between ultrasonographic and fluoroscopic measurements, or between ultrasonographic and direct open measurements when performing stress evaluation of the Lisfranc instability. Methods: Twelve fresh below-knee amputated cadaveric specimens underwent ultrasound, fluoroscopic, and direct gross evaluation of the Lisfranc stability under simulated weight bearing condition. The assessment was first performed with all Lisfranc ligamentous complex intact and thereafter with sequential transection of the dorsal Lisfranc ligament, interosseous Lisfranc ligament, and plantar Lisfranc ligament. The simulated weight bearing condition was performed with 600N of force. The distances evaluated during the experimental set up were C1-M1, C2-M2, C1-M2, C1-C2 and M1-M2. All measurements were recorded in millimeter (mm). The ultrasound machine (GE, LOGIQ E-9 ultrasound machine, Chicago, Illinois, USA) was used to assess the Lisfranc stability by measuring the distances between the hyperechoic bone contours or the pre-defined landmark of the metatarsal and cuneiform bones. Correlations between 1) Ultrasound and fluoroscopic measurements, 2) Ultrasound and direct open measurements, and 3) Fluoroscopic and direct open measurements were evaluated using Pearson correlations coefficient. Results: Strong positive correlations between ultrasonographic and direct open measurements were found when assessed for C1-M1, C1-M2, C1-C2, M1-M2 (Pearson's correlation ranged from 0.73-0.97, p-values &lt;0.001). Strong positive correlations between ultrasonographic and fluoroscopic measurements were found when assessed for C1-M1 from dorsal, medial, and plantar aspect (Pearson's correlation ranged from 0.75-0.90, p-values &lt;0.001). Strong positive correlations between fluoroscopic and direct open measurements were found when assessed for C1-M1, C1-M2, C2-M2, M1-M2 (Pearson's correlation ranged from 0.77-0.93, p-values &lt;0.001). Inter-rater and intra-rater reliability for the ultrasonographic measurements between the MSK radiologist (TK) and the foot and ankle surgeon (JS) were substantial (ICC ranged from 0.81-0.98). Conclusion: Ultrasonography is a reliable and reproducible tool for diagnosing Lisfranc ligamentous complex injuries. Both ultrasonographic and fluoroscopic measurements appear to strongly correlate with values measured by direct open measurement. Based on these data, ultrasonography is likely to become a valuable point of care diagnostic tool due to its ability to readily and dynamically evaluate suspected Lisfranc ligamentous complex injuries, without radiation exposure.

Anatomic description of the basivertebral nerve and meningeal branch of the spinal nerve in the dog

PurposeThe existence of the basivertebral nerve and meningeal branch of the spinal nerve has not been proven in dogs to date. The objectives of this study are to 1) determine whether dogs have a meningeal branch of the spinal nerve (MBSN) and a basivertebral nerve (BVN) and to (2) describe anatomical characteristics of these two nerves. Authors also put forward a discussion on the possible clinical relevance of these findings. Material and methodsDissections were performed on six embalmed dogs at the Veterinary Faculty of Barcelona with the use of stereomicroscopy and microsurgery equipment. ResultsThe MBSN (grossly) and BVN (grossly and histologically) were identified in the cervical, thoracic, and lumbar region in all dog specimens. In addition, other small fibers (suspected nerves) entering the vertebral body through small foramina close to the end plates were identified. Histological examination of the tissues confirmed the presence of nerve fibers (myelinated and unmyelinated) in suspected BVN samples. Results of the present study indicated that dogs have BVNs. Also, suspected nerve fibers were identified among the epidural fat, running from the intervertebral foramina, that likely represent the MBSN. ConclusionThese findings open up the discussion on extrapolation of treatment options employed in human medicine for “low back pain”, such as BVN ablation, which is discussed in this article. Further anatomic and clinical studies of the innervation for the vertebral body, periosteum, vasculature, dorsal longitudinal ligament and anulus fibrosus are necessary to elucidate possible anatomical variants and breed differences as well as potential clinical (e.g., therapeutic) relevance.

Dynamics of cerebrospinal fluid in correction of degenerative lumbosacral stenozis during the postoperative period in dogs

Dynamics of cerebrospinal fl parameters in postoperative period during correction of degenerative lumbosacral stenosis in dogs is an important diagnostic aspect that allows monitoring changes in the state of animals after surgery. An accurate analysis of cerebrospinal fl id provides a wide range of information about the patients neurological health. The assessment should consist of macroscopic, quantitative and microscopic analyses. Сell count is the most important and potentially sensitive indicator of disease. The aim of this study was to determine changes in the cerebrospinal fluid during the postoperative period in the correction of degenerative lumbosacral stenosis. In the study, there were 9 dogs of various breeds, aged from 2 to 8 years (experimental group), the indicators of cerebrospinal fluid and peripheral blood of 3 healthy outbred dogs obtained as a result of medical examination at the age of up to 5 years were used as a control. Surgical intervention was carried out according to the B.P. Meij, N. Bergknut, which consists in dorsal access to the L7-S 1 vertebral arches, soft tissue dissection, dissection of the dorsal ligament, formation of channels in the cranial articular processes of S 1, L7. From each animal, three liquorograms were taken for examination three times on days 1-3 after surgery, on days 12-15 and 27-30 after surgery. The study of cerebrospinal fluid was performed within 30 minutes after taking. As a result of the data obtained, it was found that the cellular composition of the liquor of dogs in the postoperative period of correction of lumbosacral stenosis was within the physiological norm, erythrocytes in the cerebrospinal fluid were not detected. The number of nucleated cells in operated dogs was the highest on days 1-3 after surgery. On the 12th-15th day after the operation, cytosis in the experimental and control groups of animals was 1.27 cells/l more. On days 27-30 after surgery, cytosis in dogs in the experimental group was lower by 0.45 cells/l compared to the control. Analysis of cerebrospinal fluid can help in the diagnostic assessment of the condition of animals in the postoperative period. However, it should be borne in mind that results are rarely specific to any particular condition and should be interpreted in the light of clinical and additional diagnostic findings.

Morphology of the Lisfranc Joint Complex

Lisfranc injuries are complicated injuries of the tarsometatarsal joint with high rates of sequelae. Both anatomy and injury of the Lisfranc joint are variably documented. Descriptions of these injuries and their associated structures vary greatly. The most injured structures are those of the Lisfranc joint complex, which involves the medial cuneiform, second and third metatarsals, and the dorsal, interosseous, and plantar Lisfranc ligaments. This study sought to examine morphology of the Lisfranc joint in cadavers. Twenty-two embalmed cadaveric feet were dissected (13 male, 9 female, 80.3 years ± 14.03) to isolate the bones and ligaments of the Lisfranc joint complex. The dorsal, interosseous, and plantar Lisfranc ligaments were present in each specimen. Each ligament was measured and morphology noted. The dissected dorsal Lisfranc ligament had consistent morphology (mean=10.8 mm ± 1.79). The interosseous Lisfranc ligament had a consistent path, but 11/17 of specimens possessed a connection to the plantar Lisfranc ligament. The plantar Lisfranc ligament demonstrated wide variability with a Y-variant (n=3) and a fan-shaped variant (n=14). Ligament thickness was greatest in the interosseous Lisfranc ligament (mean=13.74 ± 3.08) and least in the dorsal Lisfranc ligament (mean=1.36 ± 0.42). While the objective of defining joint and ligament morphology was achieved, further questions were raised. Variations of the interosseous and plantar Lisfranc ligament may play a role in susceptibility to joint injury, and arthritic changes to the joints examined raise questions regarding the prevalence of arthritis in the uninjured Lisfranc joint.

Endoscopic diagnostic and surgical orbital approach in canines.

The aim of this study is to describe new diagnostic and surgical orbital approaches using video endoscopy in canines. Four different endoscopic approaches were investigated in this study of video endoscopy in cadavers: dorsal transorbital ligament approach via incision of the orbital ligament (DTOLA), dorsal subpalpebral transconjunctival approach (DSTA), ventral subpalpebral transconjunctival approach (VSTA), and transoral orbital approach (TOA). Two additional approaches, the ventral transpalpebral approach (VTA) and dorsal caudal transmuscular approach (DCTA) along with the DTOLA and DSTA were used in clinical patients. The most technically demanding approach was DTOLA; however, it provided the best visualisation of different anterior and posterior orbital structures. Visualisation of primarily the dorsal orbital wall, dorsal portion of the eye globe, and dorsal extraconal space also was achieved by DSTA. The VSTA enabled good visualisation of the ventral orbital floor and the ventral extraconal and intraconal space. In contrast, the TOA provided relatively poor visualisation of orbital structures, limited to the ventral orbital quadrant. Meanwhile, the VTA provided visualisation similar to the VSTA, while DCTA visualisation was limited to the dorsal and caudal orbital space. Orbital endoscopy is an effective and minimally invasive procedure that can be used for diagnostic and surgical orbital procedures.

Anatomical and radiological description of ligament insertions on the radial aspect of the scaphoid bone

Anatomical studies on the radial side of the scaphoid mention inter-ligamentous connections, but without detailed description of their relations to one another. The purpose of this study was to provide an anatomical and radiological description of the ligamentous structure on the radial side of the scaphoid. High-field 3-Tesla 3D MRI scans of 7 cadaveric formaldehyde-fixed wrists were performed to assess the presence and location of each ligament. Dissection was performed in 10 wrists under microscopy on the radial side to assess the dimensions, anatomical variations and angles between ligaments in various wrist positions during in intracarpal pronation/supination, flexion/extension and ulnar/radial deviation. This study confirmed that the same ligament configuration was found on MRI and on dissection. The scaphotrapezial ligament, dorsal intercarpal ligament and radial collateral ligament fibers merge along the dorsal ridge of the scaphoid. The fibers of the radial collateral and radioscaphocapitate ligaments could be distinguished in only 4/10 specimens. Wrist position changes from intracarpal pronation to supination produced major changes in angle between the scaphotrapezial and dorsal intercarpal ligaments, while other position changes affected this angle only slightly. 3D MRI sequences allow these structures to be systematically analyzed in case of scapholunate instability. Further studies should be conducted to assess the biomechanical properties of these ligaments and the clinical consequences of isolated injury in this region.

Osteology of the White Barracudina, Arctozenus risso (Bonaparte) (Aulopiformes: Paralepididae)

Arctozenus risso, the White Barracudina, is a member of the Paralepididae, the largest family within the order Aulopiformes. In recent years the systematics of the family and the order has advanced significantly due to morphological, molecular, and holistic studies, which has led to a general agreement of their relationships. Some phylogenetic discrepancies remain in particular among the species-rich paralepidids, based on the difficulties in obtaining comprehensive taxon samples as well as the lack of morphological studies. We found an enlarged autopalatine following the enlarged ethmoid region of the skull. We identified a large ossification that covers the dorsal surface of the basibranchial copula as a basibranchial tooth plate and identified a second smaller tooth plate associated with basibranchial 4. However, the most peculiar structures are dorsal ligament ossifications that are associated with the anterior and posterior dorsal-fin pterygiophores, and supraneural 2. We hope the description of the skeletal anatomy of A. risso will help to solve some of the open questions of the phylogenetic relationships of the paralepidids and aulopiforms.

Minimum 5-Year Outcomes of Dorsal Intercarpal Ligament Capsulodesis With Scapholunate Interosseous Ligament Repair for Subacute and Chronic Static Scapholunate Instability: A Clinical Series of 5 Patients

PurposeTreatment of subacute and chronic static scapholunate instability remains challenging. We aimed to determine 5- to 10-year outcomes of dorsal intercarpal ligament capsulodesis with scapholunate interosseous ligament repair for subacute and chronic static scapholunate instability.MethodsSix patients with subacute and chronic static scapholunate instability underwent dorsal intercarpal ligament capsulodesis with scapholunate interosseous ligament repair between 2011 and 2015, and 5 of them were followed for at least 5 years after surgery. The clinical and radiological results were retrospectively investigated. All patients were male, and the mean age at surgery was 37 years (range, 21–47 years). The mean period from injury to surgery was 26.2 months (range, 2–113 months). The surgical procedure was a modification of a method reported by Szabo et al.ResultsThe mean postoperative follow-up period was 8.1 years (range, 5.1–9.5 years). Median Disabilities of the Arm, Shoulder, and Hand and Mayo wrist scores improved from 23.3 to 1.7 and from 55 to 80, respectively, from before surgery to the final follow-up. Although the median flexion angle tended to be smaller, the median extension angle tended to be greater than before surgery. The median percent grip strength increased from 72.3% before surgery to 99.2% at the final follow-up. The median scapholunate gap improved from 4.2 mm before surgery to 2.1 mm at the final follow-up. The median scapholunate angle also improved from 95.7° before surgery to 71.3° at the final follow-up. Osteoarthritic changes were observed in 2 of 5 patients at the final follow-up.ConclusionsThe scapholunate gap in all patients was within the normal range after a mean of 8.1 years of follow-up. Dorsal intercarpal ligament capsulodesis with scapholunate interosseous ligament repair is considered a good alternative for subacute and chronic static scapholunate instability based on these 5- to 10-year outcomes.Type of study/level of evidenceTherapeutic IV.

Anatomic basics and technical approaches: sacral preauricular extensions, preauricular sulci and dorsal pubic pits in modern anatomical specimens.

The aim of this study is the evaluation of three selected osseous pelvic features in modern anatomical specimen - the sacral preauricular extension, the preauricular sulcus and pits on the dorsal side of the pubic bone laterally to the symphysis. The specificity and significance of these features are under debate and their genesis is largely unclear. Descriptive data of specific soft tissue structures surrounding the anterior sacroiliac joint gap and the pubic symphysis were generated by assessing 20 fresh pelves and 12 embalmed hemipelves from human body donors. Computed tomography (CT) was performed on all specimens and three-dimensional (3D) surface models were generated and analysed. Afterwards, all the specimens underwent anatomical dissection and finally maceration. During dissection, it became apparent that the anterior sacroiliac ligament, due to its position, shape and potential impact on the sacroiliac joint and adjacent osseous structures, requires a detailed analysis of its dimension. The most promising result, in terms of the sacral preauricular extension, was that the measurements of the triangular part of the anterior sacroiliac ligament were significantly longer in females than in males. Pelvic floor muscle fibres and fascial parts were directly connected to this ligament in some specimens, which is an important starting point for a larger in-depth study. The evaluation of the anatomic structures in connection to dorsal pitting refutes the assumption that the pelvic floor muscles or fasciae could exert influence on its formation. A histological evaluation of the ligaments of the pubic symphysis, especially the dorsal pubic ligament, would be expedient to clarify the etiology of this feature.

Left rotation and dorsoventral collapse of the trachea on an adult Dartmoor cross‐gelding: Imaging diagnosis

A 9-year-old Dartmoor cross-gelding was referred for investigation and treatment of exercise intolerance, cough and abnormal respiratory noise. Endoscopic examination revealed the presence of left 90-degree rotation and dorsoventral collapse of the entire cervical trachea. Although the tracheal collapse was not obvious on laterolateral radiographs, these showed the abnormal presence of tracheal cartilages along with the dorsal and ventral limits of the trachea. Oblique radiographs showed partial tracheal collapse in the caudal aspect of the neck. Ultrasound examination revealed the presence of tracheal cartilages on the right side of the neck, dorsal tracheal ligament along with the left side of the neck and the junction between tracheal cartilage and dorsal tracheal ligament coursing over the ventral aspect of the neck. This report highlights the value of detailed examination of standard and non-standard radiographic and ultrasound imaging of the trachea to achieve correct diagnosis of tracheal collapse when associated with tracheal rotation.

High-resolution magnetic resonance imaging of the triangular fibrocartilage complex using compressed sensing sensitivity encoding (SENSE)

PurposeTo evaluate the optimal sequence for high-resolution magnetic resonance imaging (MRI) of the triangular fibrocartilage complex (TFCC) using compressed sensing-sensitivity encoding (CS-SENSE). MethodsThree-dimensional fast field echo T2-weighted images were obtained from 13 healthy volunteers using the original, high spatial resolution sequence with CS-SENSE [HR (CS-SENSE)] and without CS-SENSE (HR) and super-high spatial resolution sequence with CS-SENSE [S-HR (CS-SENSE)] and without CS-SENSE (S-HR). For qualitative analysis, the number of patients affected by motion artifacts in each sequence was counted, and the visualization of the TFCC anatomic structures and overall image quality were categorized. For the quantitative analysis, relative signal intensity (SI) and relative contrast of the lunate bone marrow, lunate cartilage, and disk proper in the wrist joint were all calculated. ResultsThe HR (CS-SENSE) sequence showed better visualization scores than the original sequence in the triangular ligament at the ulnar styloid tip, dorsal radioulnar ligament, and ulnotriquetral ligament. Similarly, the S-HR (CS-SENSE) sequence showed better visualization scores than the original sequence in the triangular ligament at the ulnar styloid tip and dorsal radioulnar ligament. Overall image quality scores were not significantly different, and motion artifacts in the HR and S-HR sequences were observed in 3 of the 13 patients. In contrast, the original sequence showed higher values than those in the HR (CS-SENSE) and S-HR (CS-SENSE) sequences in relative SI of the bone marrow and relative contrast of the cartilage-bone marrow and cartilage-disk proper. ConclusionsOut of the three sequences, the HR (CS-SENSE) sequence provided the highest visualization score and diagnostically sufficient image quality score, although relative SI and relative contrast were low. The HR (CS-SENSE) sequence may be clinically useful for imaging TFCCs.

A Large Animal Model for Orthopedic Foot and Ankle Research.

Trauma to the soft tissues of the ankle joint distal syndesmosis often leads to syndesmotic instability, resulting in undesired movement of the talus, abnormal pressure distributions, and ultimately arthritis if deterioration progresses without treatment. Historically, syndesmotic injuries have been repaired by placing a screw across the distal syndesmosis to provide rigid fixation to facilitate ligament repair. While rigid syndesmotic screw fixation immobilizes the ligamentous injury between the tibia and fibula to promote healing, the same screws inhibit normal physiologic movement and dorsiflexion. It has been shown that intact screw removal can be beneficial for long-term patient success; however, the exact timing remains an unanswered question that necessitates further investigation, perhaps using animal models. Because of the sparsity of relevant preclinical models, the purpose of this study was to develop a new, more translatable, large animal model that can be used for the investigation of clinical foot and ankle implants. Eight (8) skeletally mature sheep underwent stabilization of the left and right distal carpal bones following transection of the dorsal and interosseous ligaments while the remaining two animals served as un-instrumented controls. Four of the surgically stabilized animals were sacrificed 6 weeks after surgery while the remaining four animals were sacrificed 10 weeks after surgery. Ligamentous healing was evaluated using radiography, histology, histomorphometry, and histopathology. Overall, animals demonstrated a high tolerance to the surgical procedure with minimal complications. Animals sacrificed at 10 weeks post-surgery had a slight trend toward mildly decreased inflammation, decreased necrotic debris, and a slight increase in the healing of the transected ligaments. The overall degree of soft tissue fibrosis/fibrous expansion, including along the dorsal periosteal surfaces/joint capsule of the carpal bones was very similar between both timepoints and often exhibited signs of healing. The findings of this study indicate that the carpometacarpal joint may serve as a viable location for the investigation of human foot and ankle orthopedic devices. Future work may include the investigation of orthopedic foot and ankle medical devices, biologic treatments, and repair techniques in a large animal model capable of providing translational results for human treatment.

Sonographic anatomy and imaging of the dorsal supportive ligaments of the Chopart joint complex

AbstractAnkle sprains are common. Midfoot ligaments, particularly the dorsal ligaments of the Chopart joint complex, can be injured in combination with other ankle and foot injuries via an ankle sprain, but are clinically difficult to detect. The prevalence of injury to dorsal midfoot ligaments may be underreported as they can be overlooked, underappreciated, and underdiagnosed. Symptoms can include chronic pain, long‐term functional limitations, and physical disability due to lack of timely management. Sonographic assessment of the ankle and foot following an ankle sprain should include assessment of the dorsal midfoot ligaments. This paper will provide a description of the sonographic anatomy, appearances, and assessment of the dorsal ligaments of the Chopart joint complex. Early diagnosis of injury can allow for appropriate management and treatment.