Ulnotriquetral 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.

Etiology and Diagnostic Challenges of Ulnar Wrist Pain in Pediatric and Adolescent Patients

Diagnosing the cause of ulnar-sided wrist pain can be difficult in the pediatric and adolescent age group. While frequently used, the diagnostic accuracy of magnetic resonance image (MRI), as compared with intraoperative arthroscopic findings, is not well-described in this population. This study aimed to determine concordance rates between magnetic resonance and arthroscopic findings depending on the specific ulnar wrist pathology. A retrospective review was performed to identify pediatric and adolescent patients who underwent operative treatment of ulnar wrist pain between 2004 and 2021. Patients were included in the analysis if they were <18 years of age, complained of ulnar-sided wrist pain, underwent MRI of the affected wrist with an available report interpreted by a consultant radiologist, and had a diagnostic arthroscopy procedure within one year of imaging. Ulnar pathologies analyzed included triangular fibrocartilage (TFCC) tears, ulnotriquetral (UT) ligament tears, lunotriquetral ligament abnormalities, and ulnocarpal impaction. A total of 40 patients with a mean age of 15-years-old (range 11 to 17) were included in the analysis. Twenty-four were female, and approximately half had their dominant extremity affected. Most had a history of antecedent trauma (n= 34, 85%), but only 15/40 (38%) had a history of fracture. The mean duration of symptoms prior to presentation was six months (standard deviation, 7). The most common etiologies were Palmer 1B TFCC tears (n= 27, 68%) followed by UT split tears (n= 11, 28%). MRI overall demonstrated high specificity (82% to 94%), but low sensitivity (14% to 71%) for ulnar-sided wrist conditions. Accuracy varied between 70% and 83% depending on the specific injury. While MRI is a useful adjunct for determining the cause of ulnar wrist pathologies, findings are often discordant when compared with diagnostic arthroscopy. Surgeons should have a high degree of suspicion for TFCC-related pathology in the setting of positive provocative clinical examination despite negative MRI findings in young patients. Diagnostic IIb.

Ligamentoplasty using the ulnotriquetral ligament with wafer procedure for chronic triangular fibrocartilage complex foveal tear: Short-tem outcome

BackgroundWe developed a new ligamentoplasty technique using the ulnotriquetral ligament (UTL) via a palmar approach for cases with dorsal instability of the ulna due to a foveal tear of the triangular fibrocartilage complex (TFCC). The study aimed to evaluate the clinical outcomes of this procedure. MethodsWe retrospectively analyzed 19 cases with foveal tears of TFCC who underwent the ligamentoplasty using UTL. We harvested the UTL from the triquetrum as a pedicle graft, avoiding damage of the connection between the base of the UTL and palmar radioulnar ligament (PRUL) as possible. The graft was flipped proximally and pulled out through the bone tunnel from the ulnar fovea to the ulnar neck, then fixed to the fovea using a tenodesis screw. The function of the TFCC can be reproduced by pulling out the UTL along with the PRUL through the ulnar fovea and re-establishing the PRUL tension. Clinical results were evaluated at least 12 months following surgery. The preoperative and postoperative wrist pain level on a neumerical rating scale (NRS), the radioulnar joint (DRUJ) ballottement test, the range of motion, the grip strength, and the Patient-rated wrist evaluation (PRWE) scores were evaluated. ResultsIn all cases, the DRUJ ballottement test became negative at the final follow up compared with the normal side on manual examination. The pain levels significantly decreased as reflected by a decrease in NRS from 6.8 to 2.5 at final follow up (p < 0.01). The range of pronation/supination motion was improved from 149° to 157°. The mean PRWE score significantly decreased from 52.1 to 22.8 (p < 0.01). The postoperative pain level on the NRS scale of the three patients poorly improved. One case of the three with the 3 mm positive ulnar variance needed additional ulnar shaft shortening using a plate seven months after the primary procedure. ConclusionsThe ligamentoplasty using UTL efficiently restored the ulnar palmar stability in all 19 cases and significantly decreased the wrist pain and the PRWE scores. Study designClinical, retrospective study.

Relevant landmarks to navigate the suture locations for the arthroscopic triangular fibrocartilage complex foveal reattachment.

Key step of arthroscopic triangular fibrocartilage complex (TFCC) foveal reattachment is to suture dorsal and palmar deep components of radioulnar ligaments (RULs) to the fovea of ulnar head to ensure distal radioulnar joint stability. However, the deep components are covered and cannot be identified arthroscopically from standard radiocarpal joint view. Suturing sites described in previous studies have not been proved gasping of the deep components. The purpose of this study was to investigate our TFCC suture locations using relevant landmarks on securing the RULs' deep components for arthroscopic TFCC foveal reattachment. Wrist arthroscopy and horizontal mattress suture was performed in 20 fresh-frozen cadaver wrists. Based on close proximity of the ulnocarpal ligaments to the palmar RUL and fovea, palmar suture location was designated at the junction between ulnolunate, ulnotriquetral ligaments and palmar border of TFCC disc, whereas dorsal suture location was at dorsal border of TFCC disc, opposite the palmar location, at same distance between prestyloid recess and palmar location. The radiocarpal and ulnocarpal joint was subsequently opened to evaluate grasping of RULs' deep components and evaluate the relevant landmarks. Thirty-nine of 40 (97%) RULs' deep components were successfully grasped by the sutures. With 0.98-0.99 interobserver agreement for the measurements, mean distance between sigmoid notch to suture and suture to ulnar capsule were 5.6 ± 1.1 and 4.0 ± 0.9mm, respectively. Whereas, the dissecting point of deep component from the superficial component of the RULs was detected immediately radial to the midpoint between the sigmoid notch and the ulnar capsule (4.5 ± 0.9mm from sigmoid notch). We determined the relevant anatomical landmarks to navigate the TFCC suture locations, which reliably secure the deep components of the radioulnar ligaments for the arthroscopic TFCC foveal reattachment.

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.

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.

Outcomes Following Surgical Treatment of Hamate Arthrosis Lunotriquetral Ligament Injuries.

An institutional review board-approved study of the functional outcomes of patients after surgical treatment of hamate arthrosis lunotriquetral ligament tear (HALT) lesions was conducted. In all, 21 wrists in 19 patients underwent arthroscopic, open, or combined treatment of HALT lesions. Seven patients underwent isolated hamate debridement and 14 had concomitant procedures to address lunotriquetral pathology. Nineteen wrists underwent procedures to address additional pathology, including triangular fibrocartilage complex, ulnotriquetral ligament split, and scapholunate ligament injuries. Mayo wrist scores increased from 54 to 71. Sixteen patients had no or mild pain postoperatively, compared with none preoperatively. When stratified by lunotriquetral interosseous ligament management, 75% of the limited treatment group (none or debridement) and 78% of the additional treatment group reported improved pain. Three patients underwent additional surgeries for persistent pain. Resection of the proximal pole of the hamate can improve pain and function for patients with ulnar-sided wrist pain secondary to a HALT lesion. Concomitant wrist pathologies should be considered when determining treatment plans.

Arthroscopic-assisted 6U approach for foveal reattachment of triangular fibrocartilage complex with an anchor: Clinical and radiographic outcomes at 4 years’ mean follow-up

The main objective of this study was to evaluate the long-term clinical and radiological outcomes of arthroscopic-assisted foveal repair of proximal triangular fibrocartilage complex (TFCC) tears with an anchor. The secondary objective was to look for ligament damage associated with TFCC tears. Twenty-four patients who underwent foveal repair of the TFCC were evaluated retrospectively: 16 stage 2 and 8 stage 3 in the Atzei-EWAS classification. The TFCC was repaired with an anchor using an expanded 6U approach. Systematic testing of intrinsic and extrinsic ligaments was performed. The assessment criteria were pain on a visual analog scale (VAS), wrist joint range of motion, grip strength and pronation-supination strength, and the QuickDASH and PRWE outcome scores. X-rays were also taken to assess anchor position and to look for distal radioulnar (DRU) joint damage. The average follow-up was 44 months. After the surgical repair, pain was reduced (7.36±1.3 preoperatively vs. 0.69±1.3 postoperatively; P<0.001), the QuickDASH score improved (52.1±16 vs. 21.7±7; P<0.001), the PRWE score improved (83.7±35 vs. 9.3±12; P<0.001) as did strength (35 vs. 43kg; P<0.001). The DRU joint stability was also significantly improved. The time away from work was 2.6 months. During the arthroscopy exploration, 25% of patients had an ulnotriquetral ligament lesion and 8% had an ulnolunar ligament lesion in combination with their TFCC tear. Fifteen anchors were positioned in the anatomical fovea (62%). No DRU joint damage was noted. Six patients had neurapraxia of the dorsal branch of the ulnar nerve, although it recovered spontaneously. One patient still had hypoesthesia of the ulnar side of the fifth finger at 48 months. Arthroscopic-assisted foveal repair of the TFCC yields good results in terms of pain, strength and DRU joint stability. In one-quarter of cases, TFCC foveal tears are associated with lesions of the ulnotriquetral ligament. There is no long-term degeneration of the DRU joint.

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.

Outcomes of ulnotriquetral split tear repair: a report of 96 patients.

Ninety-six wrists (56 right and 40 left) in 96 patients (36 males and 60 females, mean age 38, range 15-77 years) underwent repair of ulnotriquetral ligament split tears between 2007 and 2016. Mayo wrist scores, visual analogue scale pain scores, and objective measures including grip strength and range of motion were obtained. Patients were assessed after a mean follow-up of 21 months (range 6-112 months). Ulnotriquetral split tear repair resulted in substantial improvements in pain and function. The mean Mayo wrist score improved from 57 preoperatively to 81 postoperatively, with 84% of patients achieving a good or excellent outcome. Pain scores decreased from 5.8 to 1.2. Grip improved from 25 kg to 29 kg. There was no significant change in range of motion of the wrist. Complications were noted in eight patients, with three experiencing continued pain, four with dysaesthesia of the dorsal sensory ulnar nerve, and one superficial infection. Arthroscopic ulnotriquetral split tear repair significantly reduced pain and improved Mayo wrist scores. Level of evidence: IV.

"Hockey wrist:" dorsal ulnotriquetral ligament injury.

Ulnar-sided wrist pain at the dorsal proximal triquetrum, especially during wrist pronation, flexion and radial deviation, is common in athletes, particularly ice hockey players. The purpose of this study was to evaluate in which position the dorsal ulnotriquetral ligament (DUTL) is placed under the greatest strain, the torque to failure and the injury pattern. We hypothesized that the DUTL is maximally strained with wrist flexion, pronation and radial deviation, and that, at failure, the ligament tears off the triquetrum. We performed a biomechanical study on 7 fresh frozen cadaveric upper extremities, with testing done on a wrist-movement stimulator to identify the position (45° of wrist flexion, 45° of wrist extension or neutral) that generated the highest and earliest strain increases in the DUTL. We performed load-to-failure testing, characterized the ligament's pattern of failure, and repaired and retested the DUTL using the same load-to-failure protocol. The DUTL reached 3 N∙m the earliest in 45° of wrist flexion (p = 0.02). The native DUTL failed at 0.35 N∙m (standard deviation [SD] 0.13 N∙m) per degree of angular stiffness, 12.93 N∙m of yield strength and with angular deformation of 57.73° (SD 20.62°). There was no significant difference in these variables between the native and repaired DUTL. Tearing occurred at a mean of 10 mm (SD 2 mm) proximal from the triquetrum's insertion in a transverse midsubstance pattern. This study showed a reproducible pattern of injury to the DUTL in a cadaveric model. Additional work is needed to further characterize the pathoanatomy of "hockey wrist."

Patient-Reported Outcome Following Ulnotriquetral Ligament Split Tear Repair.

While the clinical presentation and mechanism of injury of ulnotriquetral (UT) ligament split tear had been well described, there has been no other studies that has reported on the outcome of a UT ligament repair. This study aims to look at the patient-reported outcomes following UT ligament split tear repair. 18 wrists (13 right and 5 left) in 17 patients (12 males and 5 females, mean age 25.0 ± 8.4 years, range 16-50 years) who had UT ligament split tear and undergone surgical repair between November 2007 and December 2013 were retrospectively analysed. Patient-reported outcome of resolution of pain, and objective measurements such as improvement in grip strength and range of movement of the wrist were recorded. Patients were followed up until the pain was completely resolved or the last documented consultation. The mean follow-up duration was 16.2 months. 94% reported improvements post-surgery, of which 63% reported complete resolution of pain. 6% reported no improvement in pain post-operatively. No patient reported worsening of pain after the surgery. There was significant improvement in grip strength from a mean of 23.5 kg to 27.1 kg. There was no significant change in range of motion of the wrist. The majority of patients reported resolution or improvement of pain after surgical repair. In addition, there was statistically significant improvement in grip strength recorded.

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.

Longitudinal Split Tears of the Ulnotriquetral Ligament

A tear of the ulnotriquetral (UT) ligament can be a troubling source of pain for the athlete, especially those participating in racquet and batting sports. The UT ligament originates from the TFCC and ulnar styloid and is typically injured when an axial load is applied to an extended wrist with forearm supination. The diagnosis is based on physical exam, specifically the ulnar fovea sign. The stability of the distal radioulnar joint (DRUJ) differentiates a longitudinal split tear of the UT ligament from a TFCC foveal tear. The utility of radiographic imaging is primarily to rule out other causes of ulnar-sided wrist pain. Once a UT ligament tear has been suspected by history and examination, the diagnosis can be confirmed arthroscopically, and one or two sutures are typically sufficient for repair. Arthroscopic repair leads to excellent results with return to full athletic participation.

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.

Open repair of the triangular fibrocartilage complex from palmar aspect.

Background Although foveal tears of the triangular fibrocartilage complex (TFCC) can be surgically reattached to the fovea via a dorsal approach, the foveal lesion is difficult to visualize from the dorsal side because the extensor carpi ulnaris (ECU) sheath floor and the superficial dorsal limb of the radioulnar ligament hinders the view of the fovea. Materials and Methods Twenty-one patients with foveal tears were treated by an open repair method from the palmar aspect. Pain, instability, motion, and grip strength were evaluated after a mean follow-up period of 26 months, and each patient was rated according to the Mayo Modified Wrist Score (MMWS). Description of Technique A 4-cm skin incision is made on the palmar aspect of the ulnar fovea. The ulnar fovea is exposed through a transverse capsulotomy of the distal radioulnar joint. The distal aspect of the TFCC is also exposed between the ECU tendon sheath and the ulnotriquetral ligament. After curettage of the scar tissue in the fovea, the deep palmar and dorsal limbs of the TFCC are sutured back to the fovea using a suture anchor technique. Results Foveal TFCC tears could be repaired via a palmar surgical approach without violating the floor of the ECU tendon sheath and the superficial dorsal limb. Excellent results were achieved in 18 patients, and a good result was achieved in three. Conclusions Our result compared favorably with those reported for dorsal approach. The palmar surgical approach facilitates the inspection and repair of the TFCC foveal tears. Level of Evidence IV.

In Vivo changes in the lengths of carpal ligaments after mild dorsal angulation of distal radius fractures

The need for surgical correction in patients with malunion with mild dorsal angulation after a distal radius fracture is controversial. We specifically investigated in vivo changes in the lengths of carpal ligaments in a group of patients with mild-degree dorsal angulation following a distal radial fracture. We obtained computed tomography scans of both wrists in eight patients, whose distal radius on one side had united with dorsal angulation from 10° to 20°. The three-dimensional images of the carpus were reconstructed and the lengths of wrist ligaments were measured based on known anatomical landmarks. Compared with the contralateral uninjured side, the dorsal radiocarpal ligament and ulnotriquetral ligament were substantially lengthened (p < 0.05) and the long radiolunate ligament was substantially shortened (p < 0.05) at most wrist positions except extension. However, five other ligaments that we measured did not show significant differences in length compared with those of the uninjured side (p > 0.05). The lengths of some ligaments are substantially altered even by mild dorsal angulation of the distal radius, while the lengths of most other ligaments are not substantially affected.

Utility of Magnetic Resonance Imaging for Detection of Longitudinal Split Tear of the Ulnotriquetral Ligament

Wrist magnetic resonance imaging (MRI) has established utility in the diagnosis of wrist ligament tears, including complete tears of the ulnotriquetral ligament (UTL) and other components of the triangular fibrocartilage complex. A new type of longitudinal split tear of the UTL has recently been described with no imaging correlate. Our aims were to describe putative MRI findings associated with longitudinal UTL split tears and to assess diagnostic accuracy. We randomly selected 40 patients with arthroscopically proven longitudinal UTL split tears and 20 patients with intact UTLs, all of whom had preoperative 3 T MRI of the same wrist performed, from a list of operative notes spanning from January 1997 through October 2011, filtered with the terms "ulnotriquetral ligament" and "ulnar triquetral ligament." Two musculoskeletal radiologists who were blinded to surgical results and clinical information independently reviewed the exams. They recorded the degree of certainty of whether a longitudinal UTL split tear was present and whether several other hypothesized associated abnormalities were present. Overall sensitivity for definitive longitudinal UTL split tear detection on MRI was 58% for reader 1 and 30% for reader 2. Specificity was 60% for both. There were no statistically significant discriminatory findings. Among a selected group of patients who all had wrist arthroscopy, preoperative noncontrast 3 T wrist MRI had poor sensitivity and specificity for detection of the longitudinal split type of UTL tear. To date, MRI may be more helpful to exclude potential alternative diagnoses in the patient with ulnar wrist pain.