Ulnolunate Ligament Research Articles

Role of Vickers Ligament in the Pathogenesis of Madelung Deformity.

The Vickers ligament is thought to hinder the growth of palmar ulnar radius by tethering the lunate to the radius, leading to Madelung deformity. The purpose of this study was to clarify the nature of the Vickers ligament and investigate its pathogenesis in Madelung deformities based on our observation of the Vickers ligament. All 22 patients (33 wrists) with Madelung deformities treated surgically between 2018 and 2022 were included. The diagnosis was confirmed radiographically in all patients. The three-dimensional computed tomography (3D-CT) data of 16 patients (19 wrists) were available. Magnetic resonance imaging (MRI) data were available for 9 patients (14 wrists). Wrist arthroscopy was used in 4 patients. The Vickers ligament was resected and submitted for histopathological examination in 8 patients. Radiographic outcomes, 3D-CT, MRI, arthroscopy, surgical findings, and histopathology of the Vickers ligament were evaluated. The 3D-CT revealed that the Vickers ligament originated in the metaphysis and formed a metaphyseal defect at the palmar ulnar radius. In the sequential MR coronal images, the Vickers ligament could be divided into 3 branches, extending to the lunate, triquetrum and ulnar styloid. Arthroscopy and surgical findings revealed that the nature of the Vickers ligament was the stretched palmar ligament of the wrist. The histopathology results revealed ligamentous tissue and fibrocartilaginous metaplasia with a structure similar to that of the triangular fibrocartilage complex (TFCC). The Vickers ligament is not a separate aberrant ligament. The nature of the Vickers ligament is a combination of the stretched TFCC ligament (palmar radioulnar ligament, ulnotriquetral ligament and ulnolunate ligament) and radiolunate ligament. The possible pathogenesis of Madelung deformity might be focal early epiphyseal closure at the middle part of the sigmoid notch, which leads to focal growth retardation of the radius and pulls palmar ligaments proximally to form the Vickers ligament.

Diagnostic performance of high-resolution ultrasound in the evaluation of intrinsic and extrinsic wrist ligaments after trauma.

To investigate the role of ultrasound (US) in the evaluation of intrinsic and extrinsic ligaments of the wrist with magnetic resonance arthrography (MRA) as the reference standard. This prospective study included patients referred for MRA after wrist trauma. US examination was performed just before MRA. On the dorsal and palmar sides of the wrist, the intrinsic interosseus and midcarpal, extrinsic, and collateral ligaments were evaluated. MRA was performed on a 1.5-T unit. In the first 20 patients included, ligament thickness was independently assessed using US and MRA and thickness reproducibility was calculated. Ligament integrity was evaluated in all patients. 38 patients (22 men, 16 women; mean age: 38 years) were included. Ligament thickness reproducibility ranged between 44% for the palmar ulnocapitate ligament and 71% for the palmar scaphotriquetral ligament. US had a sensitivity, specificity, positive and negative predictive values, and accuracy of 100% in the identification of tears of the palmar (n=8) and dorsal (n=3) bands of the scapholunate ligament and the ulnar collateral ligament (n=3). It had a sensitivity of 100%, specificity of 97%, positive predictive value of 50%, negative predictive value of 100%, and accuracy of 97% in the identification of tears of the palmar ulnolunate ligament (n=1). Compared to MRA, US showed good reproducibility in the assessment of wrist ligament thickness and similar accuracy with respect to identifying tears of the scapholunate, palmar ulnolunate, and ulnar collateral ligaments.

Ulnar Wrist Pain Revisited: Ultrasound Diagnosis and Guided Injection for Triangular Fibrocartilage Complex Injuries.

The triangular fibrocartilage complex (TFCC) serves as the major stabilizer of the wrist. Its injuries can result from trauma or degeneration, both of which are strongly correlated with the loading stress on the ulnar shaft and carpal joints. The TFCC is made of the articular disc, meniscus homologue, ulnocarpal ligament, radioulnar ligament, ulnotriquetral ligament, ulnolunate ligament, and subsheath of the extensor carpi ulnaris tendon. Because of its complexity, it is challenging to confirm the exact component affected in TFCC injuries. The Palmer classification is widely used for investigation of TFCC lesions using magnetic resonance imaging. Recently, high-resolution ultrasound (US) has become more popular in diagnosing musculoskeletal disorders. However, the utility of US imaging in TFCC lesions is less common because its anatomy under US imaging is not described in the current literature. Accordingly, in this review, we aimed to propose a standard US scanning protocol for the TFCC, present relevant images for its pathologies, and illustrate appropriate US-guided injection techniques for their management.

High-resolution 3T Magnetic Resonance Imaging of the Triangular Fibrocartilage Complex in Chinese Wrists: Correlation with Cross-sectional Anatomy.

Background:The injury of the triangular fibrocartilage complex (TFCC) is a common cause of ulnar-sided wrist pain. The aim of this study was to investigate if the high-resolution 3T magnetic resonance imaging (MRI) could demonstrate the detailed complex anatomy of TFCC in Chinese.Methods:Fourteen Chinese cadaveric wrists (from four men and three women; age range at death from 30 to 60 years; mean age at 46 years) and forty healthy Chinese wrists (from 20 healthy volunteers, male/female: 10/10; age range from 21 to 53 years with a mean age of 32 years) in Beijing Jishuitan Hospital from March 2014 to March 2016 were included in this study. All cadavers and volunteers had magnetic resonance (MR) examination of the wrist with coronal T1-weighted and proton density-weighted imaging with fat suppression in three planes, respectively. MR arthrography (MRAr) was performed on one of the cadaveric wrists. Subsequently, all 14 cadaveric wrists were sliced into 2 mm thick slab with band saw (six in coronal plane, four in sagittal plane, and four in axial plane). The MRI features of normal TFCC were analyzed in these specimens and forty healthy wrists.Results:Triangular fibrocartilage, the ulnar collateral ligament, and the meniscal homolog could be best observed on images in coronal plane. The palmar and dorsal radioulnar ligaments were best evaluated in transverse plane. The ulnotriquetral and ulnolunate ligaments were best visualized in sagittal plane. The latter two structures and the volar and dorsal capsules were better demonstrated on MRAr.Conclusion:High-resolution 3T MRI is capable to show the detailed complex anatomy of the TFCC and can provide valuable information for the clinical diagnosis in Chinese.

Histological assessment of the triangular fibrocartilage complex.

The morphological structure of the seven components of triangular fibrocartilage complexes of 11 cadaver wrists of elderly people was assessed microscopically, after staining with Hematoxylin-Eosin and Elastica van Gieson. The articular disc consisted of tight interlaced fibrocartilage without blood vessels except in its ulnar part. Volar and dorsal radioulnar ligaments showed densely parallel collagen bundles. The subsheath of the extensor carpi ulnaris muscle, the ulnotriquetral and ulnolunate ligament showed mainly mixed tight and loose parallel tissue. The ulnolunate ligament contained tighter parallel collagen bundles and clearly less elastic fibres than the ulnotriquetral ligament. The ulnocarpal meniscoid had an irregular morphological composition and loose connective tissue predominated. The structure of the articular disc indicates a buffering function. The tight structure of radioulnar and ulnolunate ligaments reflects a central stabilizing role, whereas the ulnotriquetral ligament and ulnocarpal meniscoid have less stabilizing functions.

Immunohistochemical Mapping of Sensory Nerve Endings in the Human Triangular Fibrocartilage Complex.

The triangular fibrocartilage complex is the main stabilizer of the distal radioulnar joint. While static joint stability is constituted by osseous and ligamentous integrity, the dynamic aspects of joint stability chiefly concern proprioceptive control of the compressive and directional muscular forces acting on the joint. Therefore, an investigation of the pattern and types of sensory nerve endings gives more insight in dynamic distal radioulnar joint stability. We aimed to (1) analyze the general distribution of sensory nerve endings and blood vessels; (2) examine interstructural distribution of sensory nerve endings and blood vessels; (3) compare the number and types of mechanoreceptors in each part; and (4) analyze intrastructural distribution of nerve endings at different tissue depth. The subsheath of the extensor carpi ulnaris tendon sheath, the ulnocarpal meniscoid, the articular disc, the dorsal and volar radioulnar ligaments, and the ulnolunate and ulnotriquetral ligaments were dissected from 11 human cadaver wrists. Sensory nerve endings were counted in five levels per specimen as total cell amount/cm(2) after staining with low-affinity neurotrophin receptor p75, protein gene product 9.5, and S-100 protein and thereafter classified according to Freeman and Wyke. All types of sensory corpuscles were found in the various structures of the triangular fibrocartilage complex with the exception of the ulnolunate ligament, which contained only Golgi-like endings, free nerve endings, and unclassifiable corpuscles. The articular disc had only free nerve endings. Furthermore, free nerve endings were the predominant sensory nerve ending (median, 72.6/cm(2); range, 0-469.4/cm(2)) and more prevalent than all other types of mechanoreceptors: Ruffini (median, 0; range, 0-5.6/cm(2); difference of medians, 72.6; p < 0.001), Pacini (median, 0; range, 0-3.8/cm(2); difference of medians, 72.6; p < 0.001), Golgi-like (median, 0; range, 0-2.1/cm(2); difference of medians, 72.6; p < 0.001), and unclassifiable corpuscles (median, 0; range, 0-2.5/cm(2); difference of medians, 72.6; p < 0.001). The articular disc contained fewer free nerve endings (median, 1.8; range, 0-17.8/cm(2)) and fewer blood vessels (median, 29.8; range, 0-112.2/cm(2); difference of medians: 255.9) than all other structures of the triangular fibrocartilage complex (p ≤ 0.001, respectively) except the ulnolunate ligament. More blood vessels were seen in the volar radioulnar ligament (median, 363.62; range, 117.8-871.8/cm(2)) compared with the ulnolunate ligament (median, 107.7; range, 15.9-410.3/cm(2); difference of medians: 255.91; p = 0.002) and the dorsal radioulnar ligament (median, 116.2; range, 53.9-185.1/cm(2); difference of medians: 247.47; p = 0.001). Free nerve endings were obtained in each structure more often than all other types of sensory nerve endings (p < 0.001, respectively). The intrastructural analysis revealed no differences in mechanoreceptor distribution in all investigated specimens with the numbers available, showing a homogenous distribution of proprioceptive qualities in all seven parts of the triangular fibrocartilage complex. Nociception has a primary proprioceptive role in the neuromuscular stability of the distal radioulnar joint. The articular disc and ulnolunate ligament rarely are innervated, which implies mainly mechanical functions, whereas all other structures have pronounced proprioceptive qualities, prerequisite for dynamic joint stability. Lesions of the volar and dorsal radioulnar ligaments have immense consequences not only for mechanical but also for dynamic stability of the distal radioulnar joint, and surgical reconstruction in instances of radioulnar ligament injury is important.

How I manage TFCC injuries

The TFCC consists of triangular fibrocartilage (TFC), meniscus homologue, ulnolunate ligament, ulnotriquetral ligament, radioulnar ligament, and sheath floor of the extensor carpi ulnaris (ECU). The TFCC functions as a stabilizer of the ulnocarpal and DRU joints, load distributor between ulna and ulnar carpus and introduces smooth forearm rotation. The TFCC is a hammock-like shape supporting and surrounding the ulnar carpus, with the strong and nearly vertical anchor to the ulnar fovea, i.e. the RUL. During forearm rotation, the radius, the carpus and distal surface of the TFCC rotate over the ulnar head, thus simple twisting of the RUL occurs at its foveal attachment. The main stabilizer of this tiny joint is the proximal component of the TFCC, the radioulnar ligament (RUL). Central attaching fibers of the RUL at the fovea indicate isometric pattern during forearm rotation, while eccentric fibers at the fovea and base of the styloid indicate changes in length, dorsal indicates longer length in pronation, while palmar indicates longer in supination. When the RUL is torn, instability of the DRUJ occurs. The greater the tear of the RUL be, the greater instability of the DRUJ indicates. When the RUL is ruptured at the fovea, the RUL must be introduced into the central lesion of the fovea of the ulna. Classical Palmer 1B peripheral lesion also demonstrates moderate DRUJ instability, because this lesion is close to the RUL. Other traumatic lesions on the TFCC, such as Palmer 1A and 1D tear, did not indicate DRUJ instability. Diagnosis of DRUJ instability due to TFCC tear is achieved by physical examination, such as DRUJ ballottement test, arthrogram, MRI and arthroscopy. Image diagnosis is useful, however arthroscopy is a gold standard for diagnosis as well as treatment of the TFCC lesions. DRUJ arthroscopy, recently introduced arthroscopic technique, provides direct visualization of fovea lesion, where the RUL attaches. Treatments of TFCC lesions are depending on the tear site. Palmer 1B lesion is easily treated by arthroscopic capsular repair. Debridement is useful for palmer 1A or 1D tear. We also prefer to shorten the ulna, when there were degenerative changes on the TFC (Palmer Class 2) or with ulnar positive variance. Treatment options for DRUJ instability due to TFCC foveal avulsion are arthroscopic and open repair of the TFCC to the fovea for acute or sub-acute cases and reconstruction of the TFCC using ECU half-slip tendon or PL tendon for chronic TFCC injuries. Ulnar shortening procedure can be useful for partial avulsion of the RUL either dorsal or palmar, but not for complete avulsion of the TFCC at the fovea. Arthroscopic partial resection of the TFCC can no longer indicated for unstable DRUJ, because it does not introduce stabilization of the DRUJ.

Anatomy and Clinical Relevance of the Ulnocarpal Ligament

Anatomy and Clinical Relevance of the Ulnocarpal Ligament

In vivo length changes of wrist ligaments at full wrist extension

The aim of this study was to investigate the length changes of carpal ligaments when loaded in full extension in vivo. We obtained computed tomography scans of the right wrists in three positions for six volunteers: neutral; 75° extension; and 75° extension with a further 10° of radial deviation. Nine ligaments were measured and analysed with computer modelling. The results showed that the radioscaphocapitate, long radiolunate, and ulnolunate ligaments lengthened the most at full wrist extension, suggesting that they were under greatest load. The radioscapholunate, ulnocapitate, and ulnotriquetral ligaments lengthened further with the addition of wrist radial deviation. At full extension, the dorsal intercarpal ligament inserting on the scaphoid was lengthened. The dorsal radiocarpal and dorsal intercarpal ligaments inserting on the trapezoid were shortened, suggesting reduced loading. In conclusion, a number of volar carpal ligaments lengthened significantly in full wrist extension and the ulnar carpal ligaments were further lengthened at wrist radial deviation.

The Distal Oblique Bundle of the Distal Interosseous Membrane of the Forearm

The distal interosseous membrane (DIOM) of the forearm is on the distal side of the central band of the interosseous membrane, spanning the radius and ulna at the dorsal region of the pronator quadratus muscle. Recent anatomical studies have revealed that the thickness of the DIOM varies widely among specimens (0.5–2.6 mm), and an obvious thick fiber within the DIOM, called the distal oblique bundle (DOB), exists in 40% of specimens.1,2 The DOB originates from the distal ulna 54 mm (on average; range, 50–57 mm) proximal to the ulnar head and runs distally to insert on the dorsal inferior rim of the sigmoid notch of the radius (Fig. 1a,b). The DOB has an anatomical relationship with the triangular fibrocartilage complex (TFCC) (Fig. 2), both of which probably work as isometric collateral ligaments of the distal radioulnar joint (DRUJ) because the ulnar insertions of the DOB and the deep limbs of the radioulnar ligament almost coincide with the course of the axis of forearm rotation.3 Fig. 1a,b Distal interosseous membrane of the right cadaver wrist. (a) Dorsal view of the distal oblique bundle (DOB) and the central band. (b) The distal radius with the distal interosseous membrane and TFCC viewed from the dorsoulnar side. The ulna has been ... Fig. 2 Anatomical relationship between DOB and TFCC, which comprises the ulnocarpal ligamentous complex (UCLC), disk, and palmar and dorsal radioulnar (RU) ligaments. UT, ulnotriquetral ligament; UC, ulnocapitate ligament; UL, ulnolunate ligament. The TFCC is the primary soft-tissue DRUJ stabilizer, and the DIOM acts as a secondary stabilizer of the DRUJ when the dorsal and palmar radioulnar ligaments of the TFCC are cut.4,5 In normal situations, the influence of the DIOM on DRUJ stability is relatively inconsequential. However, after a TFCC injury, an ulnar head resection, or a Sauve-Kapandji procedure, the DIOM has a more important role in the stability of the ulnar head or ulnar stump. The clinical relevance of the DIOM includes its stabilizing effect on the DRUJ in ulnar shortening procedures. Recent study has revealed that ulnar shortening with the osteotomy performed proximal to the attachment of the DIOM has a more favorable effect on stability of the DRUJ as compared to distal osteotomy, especially in the presence of a DOB.6 The longitudinal resistance to ulnar shortening is significantly greater in proximal shortening than in distal shortening. These results suggest that proximal ulnar shortening in the presence of a robust DIOM could be a risk factor for nonunion, and for patients with ulnocarpal abutment but no instability of the DRUJ, it may be advantageous to perform a distal osteotomy.

Anatomy and Variants of the Triangular Fibrocartilage Complex and Its MR Appearance at 3 and 7T

Due to the small size and complexity of its constituents, the triangular fibrocartilage complex (TFCC) has been a challenging structure for magnetic resonance (MR) imaging. Higher-field MR units, at 3T and 7T, with increased spatial resolution and the development of novel MR sequences, are promising tools for an improved visualization of the ulnocarpal complex. Anatomically, the TFCC consists of the TFC proper, the ulnomeniscal homolog, the ulnar collateral ligament, the ulnotriquetral and ulnolunate ligament, and radioulnar ligaments at the volar (palmar) and the dorsal side, as well as the sheath of the extensor carpi ulnaris tendon and the capsule of the distal radioulnar joint. This article describes the normal anatomy of the TFCC and its appearance on high-field MRI. Anatomical variants, such as the positive ulnar variance, and changes during pronation and supination are addressed.

High-resolution ultrasound evaluation of extrinsic wrist ligaments in patients affected by rheumatoid arthritis

To evaluate the ultrasound features of the extrinsic wrist ligaments in rheumatoid arthritis (RA) patients in comparison with healthy volunteers. Twenty-one consecutive patients affected by RA (12 men, 9 women; mean age 57 ± 14.6years) were compared with 21 controls (12, 9; 54 ± 12.1, respectively). Wrists were evaluated using ultrasound on both palmar and dorsal sides along each ligament, using carpal bones as references. The following ligaments were studied: radioscaphocapitate, radiolunotriquetral, palmar ulnolunate, palmar ulnotriquetral, dorsal radiotriquetral, dorsal ulnotriquetral, and radial collateral ligament. Ligament number and thickness were noted. Echotexture was rated as fibrillar, fragmented, or heterogeneous; the surface was rated as smooth or blurred. The number of palmar ulnolunate and palmar ulnotriquetral ligaments detected by ultrasound in patients was significantly lower than in controls (P = 0.031 and P = 0.037, respectively). All ligaments had significantly more fragmented or heterogeneous echotexture and blurred surface and were significantly thinner in patients than in controls (P < 0.001). No correlation was found between ligament thickness and RA duration or clinical parameters. Extrinsic wrist ligaments were less detectable and thinner in patients affected by RA compared with healthy volunteers matched for age and sex. Ligament thinning did not directly correlate with RA duration and clinical parameters. • Ultrasound is increasingly used to evaluate normal anatomy of extrinsic wrist ligaments. • Extrinsic wrist ligaments are thinner in rheumatoid arthritis patients than in controls. • Extrinsic wrist ligaments are less easy to detect in rheumatoid arthritis patients. • Ligament thinning and detectability are not related to clinical parameters.

In Vivo Length Changes of Carpal Ligaments of the Wrist During Dart-Throwing Motion

The dart-throwing motion is an important movement pattern during most wrist actions. The aim of this study was to investigate length changes in the wrist ligaments in different positions of the dart-throw motion in vivo. We obtained computed tomography scans of the wrists of 6 volunteers at 5 positions of the wrist during the dart-throw motion: 20° of radial deviation with 60° of extension; 10° of radial deviation with 30° of extension; the neutral position of the carpus; 20° of ulnar deviation with 30° of flexion; and 40° of ulnar deviation with 60° of flexion. We reconstructed the 3-dimensional carpal and distal radioulnar joint structures with customized software and computed changes in length of 8 palmar and dorsal wrist ligaments. From wrist radial deviation with extension to ulnar deviation with flexion, the radioscaphocapitate, long radiolunate, ulnocapitate, and ulnotriquetral ligaments decreased significantly in length but the dorsal radiocarpal ligament and the dorsal intercarpal (DIC) ligament inserting on the trapezoid lengthened significantly; the ulnolunate ligament and the DIC ligament inserting on the scaphoid were shortest in neutral position. At wrist radial extension, the radioscaphocapitate, long radiolunate, ulnocapitate, and ulnotriquetral ligaments are lengthened and under increased tension. At wrist ulnar flexion, the dorsal radiocarpal ligament and the DIC ligament inserting on the trapezoid are lengthened and under increased tension. The ulnolunate ligament and the DIC ligament inserting on the scaphoid are the shortest and under the least tension in neutral position. These findings will help us understand the biomechanics of the carpus during the dart-throwing motion.

Changes in carpal ligament length in throwing motion of the wrist

Objective To investigate changes in wrist ligament length when the wrist is in different throwing positions.Methods Six wrists of 6 volunteers were enrolled in the experiment to obtain CT scans at 5 throwing positions of the wrist:20 degrees of radial deviation with 60 degrees of extension,10 degrees of radial deviation with 30 degrees of extension,neutral,20 degrees of ulnar deviation with 30 degrees of flexion,and 40 degrees of ulnar deviation with 60 degree of flexion.The carpal and distal radioulnar joint structures were reconstructed 3-dimensionally with customized software.Changes in length of the palmar and dorsal wrist ligaments in throwing motion were computed with the software. Results From wrist radial deviation with extension to ulnar deviation with flexion,the lengths of the radioscaphocapitate(RSC)ligament.the long radiolunate ligament(LRL),the ulnoceapitate ligament(UC)and the ulnotriquetral ligament (UT)decreased significantly(P<0.05),but the lengths of dorsal radiocarpal ligament(DRC)and the dorsal interearpal ligament(DIC)inserting on the trapezoid increased significantly(P<0.05).The lengths of ulnolunate ligament(UL)and the dorsal interearpal ligament inserting on the seaphoid were the shortest when the wrist was in the neutral position. Conclusions At wrist ulnar deviation with flexion,the RSC,LRL.UC and UT ligaments are slack.At wrist radial deviation with extension.the DRC ligament and the dorsal intercaroal ligament inserrting on the trapezoid are slack.The UL ligament and the dorsal intercarpal ligament inserting on the seaphoid are the slackest in the neutral position.These positions may be favorable to the healing of these ligaments. Key words: Carpal joints; Ligaments; Movement; In vivo study

Change in the Length of the Ulnocarpal Ligaments During Radiocarpal Motion: Possible Impact on Triangular Fibrocartilage Complex Foveal Tears

The fovea of the ulnar head is the primary attachment site for both the distal radioulnar and the ulnocarpal ligaments. Thus, both ligaments should be simultaneously affected by the traumatic avulsion of the triangular fibrocartilage complex from its ulnar attachment. Little attention, however, has been directed toward the role of the ulnocarpal ligaments in the mechanics of this type of injury. The purpose of this study was to investigate the changes in length of the ulnocarpal ligaments during various radiocarpal motions and to determine the type of radiocarpal motion that makes the ulnocarpal ligament taut and that could cause foveal avulsion if it were excessive. The 3-dimensional kinematics of the wrist joint were investigated noninvasively using a markerless bone registration technique in vivo. Magnetic resonance images of the wrists of 15 healthy volunteers were acquired in at least 5 positions during each wrist flexion-extension motion, radioulnar deviation, or the so called dart-throwing motion (radial extension-ulnar flexion motion). The 3-dimensional ligament paths of the ulnotriquetral, ulnolunate, ulnocapitate, and palmar radioulnar ligaments were modeled as the shortest paths between the fovea and the insertion point of each ligament. Changes in the 3-dimensional ligament length of each ligament between the neutral position and each wrist position were then calculated. The lengths of the ulnotriquetral and ulnocapitate ligaments increased the most on wrist radial extension, and the length of the ulnolunate ligament increased the most on wrist extension. The length of the palmar radioulnar ligament changed minimally during any motion. The ulnocarpal ligaments are likely to be stretched tensely in wrist radial extension and wrist extension. This study supports the hypothesis that one of the mechanisms responsible for a triangular fibrocartilage complex foveal tear is excessive traction of the ulnocarpal ligament caused by a fall on the outstretched hand.

Arthroscopie complémentaire de l’ostéosynthèse du radius distal par abord antérieur: Bases anatomiques de nouvelles voies arthroscopiques antérieures

Purpose of the study Morphological and morphometric studies of the wrist ligaments are scarce. The radiocapitatum and scapholunate ligaments play a pivotal role in wrist stability. Classically, a posterior approach is used for arthroscopic procedures, but an anterior approach should be possible. We conducted a cadaver study to search for new anterior portals for wrist arthroscopy. Material and methods Twenty-five formol-treated upper limbs were dissected. The classical anterior approach for open wrist surgery was executed. The different elements of the capsule-ligament system of the anterior aspect of the wrist were identified and labeled. The dissection was then extended to the ulna in search of soft points which were identified and evaluated. The different structures generally identified during wrist arthroscopy were noted. Results Two potential portals were identified in all wrists: one between the radiolunate ligament and the radio-scapho-capitatum ligament on the radial aspect and one between the radio-lunate ligament and the ulno-lunate ligament. Arthroscopic exploration enabled observation of the scapho-lunate ligament, the luno-triquetral ligament, the triangular complex of the carpus, and the entire inferior aspect of the radial joint surface, with no risk of vessel or nerve injury because of the exposure allowed by the osteosynthesis approach. Discussion Wrist arthroscopy is now accepted as a reliable technique not only for diagnostic purposes but also for therapeutic interventions for the treatment of fractures of the lower radius. Most of the arthroscopic portals described in the literature are posterior. The anterior portals described here do not involve any vascular or neurological risk since the radial approach is made under visual control by extension of the open anterior approach and on the ulnar side the noble structures are positioned medially to the ulnar flexor tendon of the carpus. This enables good triangulation necessary for the usual arthroscopic procedures. Finally, these portals have no supplementary morbidity which would be the case with percutaneous portals (injury to the medial nerve, the radial vasculonervous bundle, the radial flexor tendon). Conclusion These new arthroscopic portals are complementary to the anterior approach for open wrist surgery and enable a natural extension of joint exploration via both the radial and ulnar approaches described in this study.

Comparison Between High-Resolution MRI With a Microscopy Coil and Arthroscopy in Triangular Fibrocartilage Complex Injury

To determine whether high-resolution magnetic resonance imaging (MRI) could detect injuries to the triangular fibrocartilage complex (TFCC). Eleven patients who showed both a positive sign during the ulnocarpal stress test and tenderness at the distal end of the ulna had a high-resolution MRI using a 47-mm diameter microscopy coil. Six regions of the TFCC were investigated for injury: the radial attachment, disc, ulnar attachment of the triangular fibrocartilage (TFC), ulnotriquetral ligament, palmar radioulnar ligament (PRUL), and dorsal radioulnar ligament (DRUL). Arthroscopy was performed subsequently on each patient. For injuries to the radial attachment or the disc of the TFC, a high-resolution MRI showed 100% sensitivity and 100% specificity compared with arthroscopy. In 3 cases in which injury to the ulnar attachment of the TFC was detected with MRI and examination showed a positive piano-key sign and distal radioulnar joint instability, only 1 injury was confirmed with arthrotomy. For MRI diagnosis of an ulnotriquetral ulnolunate attachment injury, the sensitivity was 100% and the specificity was 70%; however, 3 cases had false-positive results. Finally MRI had 100% sensitivity for detecting DRUL and PRUL injuries, although specificities were 75% and 83%, respectively. With MRI there were 2 false-positive DRUL injury diagnoses and 1 false-positive PRUL injury diagnosis. High-resolution MRI using a microscopy surface coil allowed assessment of each TFCC component and showed a higher accuracy for diagnosing injuries to the radial attachment and the disc of the TFC compared with previous studies. High-resolution MRI, however, was not able to diagnose DRUL, PRUL, or ulnolunate ligament injuries accurately. Diagnostic III.

Scapholunate ligament in carpal kinematics: An anatomical study

Eighty-nine MR examinations of the wrist were retrospectively analyzed. MRI results were compared with clinical findings and/or arthroscopy. Thin proton density and T2 weighted sequences and 3D DESS weighted sequences were applied on a 1.5 T scanner. On the palmar side three radiocarpal ligaments are recognized including the radioscaphocapitate, radiolunotriquetral, radioscapholunate, and midcarpal triquetroscaphoidal ligaments. Ulnocarpal ligaments include the ulnolunate ligament and the ulnotriquetral ligament. On the dorsal side three ligaments are recognized: the dorsal radiolunotriquetral, and the midcarpal triquetroscaphoidal and triquetro-trapezoido-trapezial. The collateral ligaments include the radial and ulnar collateral ligament. MR is a valuable technique in the assessment of the extrinsic and midcarpal ligaments. Depiction of the extrinsic ligaments can best be accomplished with coronal 3D DESS sequences and sagittal and transverse proton density and T2 weighted sequences with thin slices.

Ultrasonographic evaluation of normal extrinsic and intrinsic carpal ligaments: preliminary experience

To determine normal anatomy of extrinsic and intrinsic carpal ligaments at ultrasonography (US). In the first part of the study, two musculoskeletal radiologists retrospectively reviewed in consensus the photographs of anatomic sections and dissections derived from 20 cadaveric wrists. This cadaveric study gave the two readers the opportunity to learn the anatomy and orientation of the various extrinsic and intrinsic carpal ligaments and, thus, to develop a US protocol to facilitate the recognition of each carpal ligament. In the second part of the study, these two radiologists prospectively and independently evaluated the visibility of extrinsic and intrinsic carpal ligaments in 30 wrists of volunteers, using the same US protocol. With regard to extrinsic carpal ligaments, the radioscaphocapitate ligament (partially visible, 38%; completely visible, 62%), the radiolunotriquetral ligament (partially visible, 27%; completely visible, 73%), the palmar ulnotriquetral ligament (partially visible, 12%; completely visible, 88%), and the dorsal radiotriquetral ligament (partially visible, 7%; completely visible, 93%) were visualized at US. The dorsal ulnotriquetral ligament (partially visible, 21%; completely visible, 74%), the ulnolunate ligament (partially visible, 5%; completely visible, 70%), and the radial collateral ligament (partially visible, 18%; completely visible, 12%) were more difficult to recognize. The radioscapholunate ligament was never seen. With regard to intrinsic carpal ligaments, the dorsal (partially visible, 11%; completely visible, 89%) and palmar (partially visible, 38%; completely visible, 62%) scaphotriquetral ligaments as well as the dorsal scapholunate ligament (partially visible, 3%; completely visible, 97%) were visualized at US. The dorsal lunotriquetral ligament (partially visible, 39%; completely visible, 61%) and the palmar scapholunate ligaments (partially visible, 12%; completely visible, 81%) were more difficult to recognize. US may be helpful in identifying the major extrinsic and intrinsic carpal ligaments.

High-resolution MR imaging of triangular fibrocartilage complex (TFCC): comparison of microscopy coils and a conventional small surface coil

To compare MR images of the triangular fibrocartilage complex (TFCC) using microscopy coils with those using a conventional surface coil qualitatively and quantitatively. Proton density-weighted images and T2*-weighted images of the TFCC from ten normal volunteers were obtained with a conventional surface coil (C4 coil; 80 mm in diameter), a 47-mm microscopy surface coil and a 23-mm microscopy surface coil) at 1.5 T. Qualitative image analysis of MR images with three coils was performed by two radiologists who assigned one of five numerical scores (0, nonvisualization; 1, poor; 2, average; 3, good; 4, excellent) for five TFCC components, which were disc proper, triangular ligament, meniscus homologue, ulnotriquetral and ulnolunate ligament. Quantitative analysis included the signal-to-noise ratio (S/N) of the disc proper of TFCC, the lunate cartilage, the lunate bone and the contrast-noise-ratio (C/N) between articular cartilage and disc proper or bone marrow were measured. All structures show higher scores qualitatively on MR with microscopy coils than those with a C4 coil, and the difference was significant with the exception of the ulnolunate ligament. MR with microscopy coils showed significantly higher S/N values than those with a conventional surface coil (P<0.05 to P<0.001). T2*-weighted images using microscopy coils showed significantly higher cartilage-disc proper C/N and cartilage-bone marrow C/N (P<0.01 to P<0.001). On proton density-weighted images, the C/N between cartilage and disc proper with two microscopy coils was significantly higher (P<0.01) than that with a conventional coil. High-resolution MR images of the normal wrist using microscopy coils were superior to those using a conventional surface coil qualitatively and quantitatively. High-resolution MR imaging with a microscopy coil would be a promising method to diagnose TFCC lesions.