Morphology of the triangular fibrocartilage complex of the Vietnamese adult: a cadaveric study.

Objective: This descriptive study aims to describe various anatomical morphological indicators of the triangular fibrocartilage complex (TFCC) in Vietnamese adults. Materials and methods: We analyzed 30 wrist joints from 15 fresh cadavers. To access the components of the TFCC, the wrist joints were dissected and measured, and anatomical morphological indices, inclu-ding length, width, thickness, origin, and insertion, were recorded. Results: Nine of 30 articular discs had central tears. The average length of the articular disc was 10.05±2.26 mm, while the average width was 12.10±1.39 mm. The average thickness of the articular disk on the ulnar side was 1.56±0.42 mm, while the average thickness of the articular disk on the radial side was 2.63±1.04 mm. Most meniscus homologues (86.6%) were of the narrow opening type according to the Ishii classification, with a horizontal dimension of 6.98±2.05 mm, anteroposterior diameter of 8.94±2.46 mm, and thickness of 1.27±0.41 mm. The volar radioulnar ligament averaged 12.75±2.17 mm in length and 2.54±0.77 mm in width, while the dorsal radioulnar ligament ave-raged 12.82±2.63 mm in length and 2.37±0.65 mm in width. The ulnar collateral ligament averaged 13.59±2.79 mm in length, 3.75±0.80 mm in width, and 0.95±0.46 mm in thickness. The ulnolunate and ulnotriquetral ligaments had average lengths of 7.34±2.87 mm and 5.70±2.98 mm, widths of 3.93±1.55 mm and 4.87±1.06 mm, and thicknesses of 0.96±0.61 mm and 1.43±0.98 mm, respectively. Conclusions: There are no differences in the shape or structure of the adult Vietnamese TFCC. No significant differences were noted in any TFCC component according to wrist side or gender.

The triangular fibrocartilage complex in the human wrist: A scoping review toward uniform and clinically relevant terminology.

The aim of this scoping review was to assess the composition, terminology, and anatomy of the triangular fibrocartilage complex (TFCC) of the wrist and propose unambiguous terminology regarding the individual components. The review was conducted according to the methodological framework by Arksey and O'Malley (International Journal of Social Research Methodology, 2005, 8, 19-32). Electronic databases were searched from inception until September 1, 2021 for original anatomical studies, using MeSH terms and keywords on terminology and anatomy of TFCC components. Studies using gross dissections or macro- or microscopic histology were included. Animal studies, fetal studies and studies with unknown disease status, were excluded. A total of 24 studies were included. The articular disc, the radioulnar ligaments, the meniscus homologue and the extensor carpi ulnaris tendon (sub)sheath were unanimously classified as TFCC components. One study did not include the ulnolunate and ulnotriquetral ligaments and only one study did include the ligamentum subcruentum. The largest disagreement existed regarding the inclusion of the ulnar collateral ligament. Terminological ambiguity was seen in "triangular fibrocartilage," "triangular ligament," "igamentum subcruentum," and the "proximal and distal lamina." Anatomical ambiguity existed especially regarding the radioulnar ligaments, the ulnar attachments of the TFCC and the ulnar collateral ligament. Definitions of the individual TFCC components are redundant, ambiguous, and ill-defined and therefore subject to different interpretations. In order to preclude confusion, consensus regarding terminology is recommended. We proposed a concise definition of the healthy TFCC that can be used as a starting point for future studies and current clinical practice.

Magnetic Resonance Imaging of the Triangular Fibrocartilage Complex.

The imaging evaluation and interpretation of the triangular fibrocartilage complex (TFCC) is both challenging and rewarding for the radiologist and surgeon alike. The TFCC comprises a complicated group of fibrocartilaginous and ligamentous structures at the ulnar aspect of the wrist that plays an important role in wrist biomechanics. It is the main stabilizer of the distal radioulnar and ulnocarpal joints and functions to distribute compressive forces at the ulnocarpal joint during axial loading. Derangement of the TFCC is the most common source of ulnar-sided wrist pain. Imaging plays an important role in the diagnosis and management of these lesions. The TFCC can anatomically be divided into proximal and distal parts to emphasize the role that the proximal TFCC has in stabilizing the distal radioulnar joint. Tears can be divided into traumatic and degenerative categories using the Palmer classification. Further subclassification based on the location for traumatic tears and the degree of derangement in degenerative tears guides clinical management. The vascular anatomy is important in determining management options for various lesions. A detailed understanding of the normal anatomy of the TFCC, imaging limitations and pitfalls, the Palmer classification system, and current treatment options is critical to the accurate and clinically useful interpretation of radiologic examinations of the TFCC.

Transulnar Styloid Foveal TFC Reconstruction: With a Palmaris Longus Tendon Graft.

We describe an evolution of the senior author's technique in the repair or reconstruction of foveal triangular fibrocartilage complex tears. This technique uses a transulnar styloid approach, which gives superior access to the fovea, without disruption of secondary stabilizers. A free palmaris longus graft is used to stabilize and augment the triangular fibrocartilage complex with an interosseous anchor through an ulnar tunnel.

All-Arthroscopic Triangular Fibrocartilage Complex Ligamentoplasty for Chronic DRUJ Instability.

Peripheral injuries of the triangular fibrocartilage complex can produce pain and instability of the distal radioulnar joint (DRUJ). There are several techniques for the repair or reconstruction of these injuries, which vary depending on the location, healing capacity, and viability of the tissues, as described by the classification proposed by Atzei. In irreparable chronic injuries of the triangular fibrocartilage complex in which there are no associated chondral injuries of the DRUJ or in failures in previous repair techniques, ligament reconstruction plasty with tendon grafts, either by open surgery or assisted by arthroscopy, are the treatments of choice. We present a completely arthroscopic reconstruction technique of the triangular fibrocartilage complex by means of tendon graft to provide stability to the DRUJ. This reconstruction technique provides a more stable reconstruction after the integration of the tendon plasty in the bone tunnels, based on the anatomic insertions of the triangular fibrocartilage in the fovea and in the corners of the dorsal and volar sigmoid notch, along with the advantages offered by arthroscopy in terms of recovery time, esthetic result, less mobility loss, and pain.

Chronologic and Geographic Trends of Triangular Fibrocartilage Complex Repair.

This article shows trends in triangular fibrocartilage complex (TFCC) repair since 1990 by geographic area and year. The repair methods presented in the literature were inside-out, outside-in, all-inside, and open repair. The outside-in technique was reported most often for ulnar-side tears, whereas the inside-out technique was reported most frequently for radial-side tears. Recently, a foveal reattachment technique for ulnar-side tears has garnered attention and has been reported with increasing frequency, especially in Asia, because the deepest portion of TFCC, attached to fovea, plays a key role in stabilizing the distal radioulnar joint. Understanding these trends can help clinicians best treat TFCC tears.

Arthroscopic Management of Triangular Fibrocartilage Complex Peripheral Injury.

Patients suffering from ulnar-sided wrist pain after trauma may develop tenderness, clicking, a positive fovea sign, or instability of the distal radioulnar joint. If the pain is persistent, conservative treatment does not help, and the patient agrees to surgery, arthroscopy may reveal a triangular fibrocartilage complex (TFCC) injury with capsular detachment, foveal avulsion, or a combination thereof. Capsular reattachment is possible using an arthroscopic assisted technique. The reattachment can be performed with an inside-out, outside-in, or all-inside technique, providing good to excellent results, which tend to persist over time, in 60% to 90% of cases.

Arthroscopic-Assisted Triangular Fibrocartilage Complex Reconstruction.

Injury of the triangular fibrocartilage complex (TFCC) is a common cause of ulnar-sided wrist pain. Volar and dorsal radioulnar ligaments and their foveal insertion are the most important stabilizing components of the TFCC. In irreparable tears, anatomic reconstruction of the TFCC aims to restore normal biomechanics and stability of the distal radioulnar joint. We proposed a novel arthroscopic-assisted technique using a palmaris longus tendon graft. Arthroscopic-assisted TFCC reconstruction is a safe and effective approach with outcomes comparable to conventional open reconstruction and may result in a better range of motion from minimizing soft tissue dissection and subsequent scarring.

Rehabilitation of distal radioulnar joint instability.

Distal radioulnar joint (DRUJ) instabilities are common and often combined with other injuries of the interosseous membrane and/or the proximal radioulnar joint. Once they are diagnosed and the treatment is chosen, physiotherapists have limited choices due to the lack of validated protocols. The benefits of proprioception and neuromuscular rehabilitation have been brought to light for the shoulder, knee and ankle joints, among others. However, no program has been described for the DRUJ. The purpose of this article is to study the muscular elements responsible for active DRUJ stability, and to propose a proprioceptive rehabilitation program suited to this condition.

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.

High-Resolution 3T MR Imaging of the Triangular Fibrocartilage Complex.

This study is intended as a review of 3Tesla (T) magnetic resonance (MR) imaging of the triangular fibrocartilage complex (TFCC). The recent advances in MR imaging, which includes high field strength magnets, multi-channel coils, and isotropic 3-dimensional (3D) sequences have enabled the visualization of precise TFCC anatomy with high spatial and contrast resolution. In addition to the routine wrist protocol, there are specific techniques used to optimize 3T imaging of the wrist; including driven equilibrium sequence (DRIVE), parallel imaging, and 3D imaging. The coil choice for 3T imaging of the wrist depends on a number of variables, and the proper coil design selection is critical for high-resolution wrist imaging with high signal and contrast-to-noise ratio. The TFCC is a complex structure and is composed of the articular disc (disc proper), the triangular ligament, the dorsal and volar radioulnar ligaments, the meniscus homologue, the ulnar collateral ligament (UCL), the extensor carpi ulnaris (ECU) tendon sheath, and the ulnolunate and ulnotriquetral ligaments. The Palmer classification categorizes TFCC lesions as traumatic (type 1) or degenerative (type 2). In this review article, we present clinical high-resolution MR images of normal TFCC anatomy and TFCC injuries with this classification system.

Proximity of the Triangular Fibrocartilage Complex to Key Surrounding Structures and Safety Assessment of an Arthroscopic Repair Technique: A Cadaveric Study.

PURPOSE: To quantify the distance of the dorsal ulnar sensory branch, floor of the extensor carpi ulnaris (ECU) subsheath, and ulnar neurovascular bundles from the triangular fibrocartilage complex (TFCC), and secondarily to assess the safety of an all-inside arthroscopic repair of the TFCC with a commonly used meniscal repair device with respect to the aforementioned structures. METHODS: A custom K-wire with 1-mm gradation was used to determine the distance of at-risk structures from the periphery of the TFCC in 13 above-elbow human cadaver specimens. An all-inside repair of the TFCC at the location of a Palmer 1B tear was then performed using a commonly employed meniscal repair device. The distance from the deployed devices to the structure in closest proximity was then measured using digital calipers. RESULTS: The mean distance from the deployed device to the nearest structure of concern for iatrogenic injury was 9.4 mm (range, 5-15 mm). The closest structure to iatrogenic injury was usually, but not always, the dorsal ulnar sensory nerve in 9 of 13 wrists (69.2%) at 9.3 mm (range, 5-15 mm); on 3 occasions it was instead the ulnar nerve (23.1%) at 9.5 mm (range, 9-10 mm), and on 1 occasion 6 mm from the flexor digitorum profundus to the little finger (7.7%). Forearm rotation had no significant effect on measured distances (ulnar nerve: P = .98; dorsal sensory: P = .89; ECU: P = .90). The largest influence of forearm rotation was a 0.4-mm difference between pronation and supination with respect to the distance of the TFCC periphery on the ECU subsheath. CONCLUSIONS: An all-inside arthroscopic TFCC repair using a commonly used meniscal repair device appears safe with respect to nearby neurovascular structures and tendons under typical arthroscopic conditions. CLINICAL RELEVANCE: An all-inside arthroscopic TFCC repair using a commonly employed meniscal repair device appears safe in terms of proximity to important structures although further clinical investigation is warranted.

Extensor Carpi Ulnaris Subsheath Reconstruction.

Acute extensor carpi ulnaris (ECU) subsheath injury and chronic subsheath insufficiency may result in symptomatic ECU instability at the level of the distal ulna osseous sulcus. Associated ulnocarpal (ie, triangular fibrocartilage complex) and ECU intrinsic tendinopathic changes may accompany subsheath pathologies and require concomitant treatment. Surgical treatment is indicated in refractory cases despite nonoperative treatment and may consist of repair of the torn edge of the ECU subsheath or, more frequently, reconstruction utilizing a radially based extensor retinacular sling. An ECU subsheath reconstructive technique is detailed.

[Classification and MR imaging of triangular fibrocartilage complex lesions].

OBJECTIVE: To explore the MRI characteristics of injuries of triangular fibrocartilage complex (TFCC), and provide imaging basis for the early diagnosis and treatment of the injuries. METHODS: A total of 10 healthy volunteers without wrist injuries and 200 patients from Beijing Jishuitan Hospital who complained ulnar-sided wrist pain and were highly suspected as the injury of TFCC underwent the wrist magnetic resonance examination. All subjects were in a prone position and underwent examination on coronal T1WI scan and PD-FS on 3 planes respectively. Then the MRI characteristics of 3 healthy volunteers and 67 patients with TFCC injuries that confirmed by operation were analyzed. According to the comparative analysis of normal anatomy and Palmer classification, the injuries were classified and MRI features of different types of injuries were analyzed. At last, imaging findings were compared with surgical results. RESULTS: Three healthy volunteers without injuries showed mainly in low signal intensity on T1WI and PD-FS images. According to Palmer classification, there were 52 traumatic injuries (ⅠA 9, ⅠB 25, ⅠC 3, ⅠD 13, In addition, 1 has central perforation and ulnar avulsion and 1 has ulnar and radial injuries simultaneously) and 15 degenerative injuries (ⅡA 5, ⅡB 1, ⅡC 2 , ⅡD 1 , ⅡE 6) among 67 patients. The central perforation mainly demonstrated as linear high signal perpendicular to the disk, and run in a sagittal line. The ulnar, distal, and radial avulsion mainly showed the injuries were irregular, the structures were ambiguous, and there was high signal intensity in the injured structures on PD-FS. Degenerative injuries demonstrated the irregularity of TFC and heterogeneous signals on PD-FS. There were mixed intermediate-high signals and changes in the articular cartilage of lunate and ulna, high signal in the lunotriquetral ligament and ulnocarpal or radioulnar arthritis. CONCLUSION: MRI can demonstrate the anatomy of TFCC accurately, evaluate and make the general classification of injuries. It is of significance for the early diagnosis and treatment protocols of the TFCC injuries.

The Traumatized TFCC: An Illustrated Review of the Anatomy and Injury Patterns of the Triangular Fibrocartilage Complex.

The triangular fibrocartilage complex (TFCC) plays an important role in wrist biomechanics and is prone to traumatic and degenerative injury, making it a common source of ulnar-sided wrist pain. Because of this, the TFCC is frequently imaged, and a detailed understanding of its anatomy and injury patterns is critical in generating an accurate report to help guide treatment. In this review, we provide a detailed overview of TFCC anatomy, its normal appearance on magnetic resonance imaging, the spectrum of TFCC injuries based on the Palmer classification system, and pitfalls in accurate assessment.

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.

The Dorsal Triangular Fibrocartilage of the Metacarpophalangeal Joint: A Cadaveric Study.

PURPOSE: To describe a fibrocartilaginous structure on the dorsal surface of the metacarpophalangeal (MCP) joint. METHODS: A combination of anatomical dissection, histology, ultrasound, and magnetic resonance imaging was undertaken to explore the anatomical structure described, with clinical correlation undertaken by surgical exploration of MCP joints. RESULTS: A dorsal structure of the MCP joint was identified as fibrocartilagenous in composition, triangular in shape, and-together with the volar plate and collateral and accessory collateral ligaments-forming a deepened dorsal fossa in which the metacarpal head invaginated. It was attached to the extensor tendon by loose connective tissue and formed part of the joint capsule. CONCLUSIONS: The dorsal fibrocartilage of the MCP joint is a constant anatomical structure that appears to complement the structural support for the metacarpal head and extensor tendon. Possible functions include stabilization of the extensor tendon, formation of a dorsal fossa, prevention of extensor tendon attrition, and synovial fluid production. Its structure and function may have implications in future development of joint replacement devices. CLINICAL RELEVANCE: This study adds to the collective knowledge about the precise anatomy of the MCP joint. Reconstructive surgery and, in particular, joint replacement surgery should consider the potential function and importance of this structure when designing interventions on the joint.

Update TFCC: histology and pathology, classification, examination and diagnostics.

The TFCC is a crucial stabilizer of the DRUJ. Based on its superficial and deep fibers, the TFCC guarantees unrestricted pronation and supination which is essential for performing sophisticated tasks. The ability to perform complex movements is of uppermost importance for hand function. Therefore, a functional intact TFCC is a prerequisite in this context. The articular disc of the TFCC is a fibrocartilaginous extension of the superficial zone of hyaline articular cartilage which arises from the radius. The peripheral 10-40 % of the TFC is vascularized. Degeneration of the articular disc is common with increasing age. Even though the central part of the articular disc is avascular, potential regeneration of lesions could be detected. The Palmer and Atzei classifications of TFCC lesions are complementary. TFCC innervation is based on different nerves. There is a high variability. A diligent clinical examination facilitates specific tests which help to allocate symptoms to the pathology. Therefore, a thorough clinical examination is not dispensable. Wrist arthroscopy remains the "gold standard" for diagnosing TFCC pathologies despite technical progress in imaging modalities. MR arthrography may have the potential to become a real alternative to wrist arthroscopy for diagnosing TFCC pathologies with technical progress in the future.

The role of imaging in diagnosing diseases of the distal radioulnar joint, triangular fibrocartilage complex, and distal ulna.

OBJECTIVE: The purpose of this article is to review the anatomy, biomechanics, and multimodality imaging findings of common and uncommon distal radioulnar joint (DRUJ), triangular fibrocartilage complex, and distal ulna abnormalities. CONCLUSION: The DRUJ is a common site for acute and chronic injuries and is frequently imaged to evaluate chronic wrist pain, forearm dysfunction, and traumatic forearm injury. Given the complex anatomy of the wrist, the radiologist plays a vital role in the diagnosis of wrist pain and dysfunction.

The athlete's wrist: ulnar-sided pain.

Ulnar-sided wrist pain is one of the most common symptoms in athletes of baseball, racket sports, golf, and wrestling where there is frequent use of the hands as well as in soccer and running, where hand use is minimal. Compared with all wrist injuries, ulnar-sided wrist injury is a relatively serious condition for athletes because it plays an important role in performing a strong grip and in the rotation of the forearm. Ulnar-sided wrist pain in athletes can be related to acute trauma or chronic overuse. Acute trauma can lead to bone fractures and sprains/tears of ligaments. Repetitive mechanical stresses to tendons, ligaments, and the joint structures can lead to tendinitis or osteoarthrosis. Diagnosis of the ulnar-sided wrist pain is challenging both for hand surgeons and radiologists because of the small and complex anatomy. In the present article, we discuss mechanisms of wrist injury, sports-specific ulnar-sided wrist injuries, and the differential diagnosis of ulnar-sided wrist pain.