Diagnostic value of MRI in traumatic triangular fibrocartilage complex injuries: a retrospective study.

BACKGROUND: Triangular fibrocartilage complex (TFCC) injuries commonly manifest as ulnar-sided wrist pain and can be associated with distal radioulnar joint (DRUJ) instability and subsequent wrist functional decline. This study aimed to assess the diagnostic value of MRI compared to wrist arthroscopy in identifying traumatic TFCC injuries and to determine the distribution of different TFCC injury subtypes in a normal clinical setting. METHODS: The data of 193 patients who underwent both preoperative wrist MRI and wrist arthroscopy were retrospectively reviewed. The analysis focused on the proportion of subtypes and the diagnostic value of MRI in traumatic TFCC injuries, utilizing Palmer's and Atzei's classification with wrist arthroscopy considered as the gold standard. RESULTS: The most prevalent subtype of TFCC injuries were peripheral injuries (Palmer 1B, 67.9%), followed by combined injuries (Palmer 1 A + 1B, 14%; Palmer 1B + 1D, 8.3%). Compared with wrist arthroscopy, the diagnostic sensitivity, specificity, negative predictive value (NPV), and Kappa value of MRI was as follows: traumatic TFCC tears 0.99 (95% CI: 0.97-1), 0.90 (0.78-0.96), 0.97 (0.87-1), and 0.93; styloid lamina tears 0.93 (0.88-0.96), 0.53 (0.30-0.75), 0.47 (0.26-0.69), and 0.44; and foveal lamina tears 0.85 (0.74-0.92), 0.38 (0.29-0.49), 0.79 (0.65-0.89), and 0.21. CONCLUSIONS: The diagnostic value of MRI in traumatic TFCC injuries has been confirmed to be almost perfect using Palmer's classification. In more detailed classification of TFCC injuries, such as pc-TFCC tears classified by Atzei's classification, the diagnostic accuracy of MRI remains lower compared to wrist arthroscopy. Radiological associated injuries may offer additional diagnostic value in cases with diagnostic uncertainty.

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

BACKGROUND: We 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. METHODS: We 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. RESULTS: In 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. CONCLUSIONS: The ligamentoplasty using UTL efficiently restored the ulnar palmar stability in all 19 cases and significantly decreased the wrist pain and the PRWE scores. STUDY DESIGN: Clinical, retrospective study.

Combined repair of scapholunate ligament (SL) and triangular fibrocartilage complex (TFCC) lesions in chronic trauma of the wrist: surgical treatment of 14 patients.

PURPOSE: Injuries of the scapholunate ligament (SL) and of the triangular fibrocartilage complex (TFCC) represent the main ligament injuries of the traumatic wrist. A double injury of the SL and TFCC ligaments is quite common in the trauma setting, and clinical examination is fundamental. MRI allows to detection of a TFCC and SL ligament injury, but wrist arthroscopy is still the gold standard for diagnosis. We present the clinical results of the combined reconstruction of chronic scapholunate ligament and TFCC injury. MATERIALS AND METHODS: Fourteen patients were treated at our hospital with a combined scapholunate ligament and TFCC complex repair. All patients were surgically treated by the same senior author, after a diagnostic arthroscopy that revealed a lesion of both structures. A comparison between the pre-operative and post-operative pain and function was carried out using VAS, Disability of Arm, Shoulder and Hand score (DASH) and Patient-Related Wrist/Hand Evaluation score (PRWHE). Wrist range of motion and strength were also compared following surgery. RESULTS: All patients had a mean follow-up of 54 months. A statistically significant improvement was observed both with the reduction in pain (VAS from 8.9 to 5) and with the improvement of functionality scores (DASH from 63 to 40 and PRWHE from 70 to 57) and with the increase in ROM and strength. In only one patient (7%), because of pain and instability, a supplement operation was needed (Sauve-Kapandji procedure) 3 months after the initial surgery. CONCLUSIONS: The simultaneous repair of the SL and TFCC complex has shown a good success rate in both decreasing pain and regaining functionality.

Interdisciplinary consensus statements on imaging of DRUJ instability and TFCC injuries.

OBJECTIVES: The purpose of this agreement was to establish evidence-based consensus statements on imaging of distal radioulnar joint (DRUJ) instability and triangular fibrocartilage complex (TFCC) injuries by an expert group using the Delphi technique. METHODS: Nineteen hand surgeons developed a preliminary list of questions on DRUJ instability and TFCC injuries. Radiologists created statements based on the literature and the authors' clinical experience. Questions and statements were revised during three iterative Delphi rounds. Delphi panelists consisted of twenty-seven musculoskeletal radiologists. The panelists scored their degree of agreement to each statement on an 11-item numeric scale. Scores of "0," "5," and "10" reflected complete disagreement, indeterminate agreement, and complete agreement, respectively. Group consensus was defined as a score of "8" or higher for 80% or more of the panelists. RESULTS: Three of fourteen statements achieved group consensus in the first Delphi round and ten statements achieved group consensus in the second Delphi round. The third and final Delphi round was limited to the one question that did not achieve group consensus in the previous rounds. CONCLUSIONS: Delphi-based agreements suggest that CT with static axial slices in neutral rotation, pronation, and supination is the most useful and accurate imaging technique for the work-up of DRUJ instability. MRI is the most valuable technique in the diagnosis of TFCC lesions. The main indication for MR arthrography and CT arthrography are Palmer 1B foveal lesions of the TFCC. CLINICAL RELEVANCE STATEMENT: MRI is the method of choice for assessing TFCC lesions, with higher accuracy for central than peripheral abnormalities. The main indication for MR arthrography is the evaluation of TFCC foveal insertion lesions and peripheral non-Palmer injuries. KEY POINTS: • Conventional radiography should be the initial imaging technique in the assessment of DRUJ instability. CT with static axial slices in neutral rotation, pronation, and supination is the most accurate method for evaluating DRUJ instability. • MRI is the most useful technique in diagnosing soft-tissue injuries causing DRUJ instability, especially TFCC lesions. • The main indications for MR arthrography and CT arthrography are foveal lesions of the TFCC.

MRI-Related Risk Factors for Distal Radioulnar Joint Instability.

OBJECTIVE: Instability of the dorsal radioulnar ligament (DRUL) is caused by multiple factors from bony and soft tissue structures. Studies of DRUJ instability based on MRI have rarely been reported. This study aims to investigate related instability factors in the distal radioulnar joint (DRUJ) after trauma based on MRI imaging. METHODS: The MRI imaging was performed on 121 post-traumatic patients with or without DRUJ instability from April 2021 to April 2022. All patients demonstrated pain or attenuated wrist ligamentous tissue quality with physical examination. The interesting variables, including age, sex, the distal radioulnar transverse shape, the triangular fibrocartilage complex (TFCC), DRUL, the volar radioulnar ligament (VRUL), distal interosseus membrane (DIOM), the extensor carpi ulnaris (ECU), and pronator quadratus (PQ), were analyzed using univariable and multivariable logistic regression model. The different variables were compared in radar plots and bar chart. RESULTS: An average age of 121 patients was 42.16 ± 16.07 years. The 50.4% DRUJ instability existed in all patients and the distal oblique bundle (DOB) presented in 20.7% of patients. The TFCC (p = 0.03), present DIOM (p = 0.001), and PQ (p = 0.006) were identified to be significant in final multivariable logistic model. The percentage of patients with ligament injuries were general higher in DRUJ instability group. The patients with absent DIOM had a higher rate in DRUJ instability, TFCC, and ECU injury. There was higher stability in shape of C-type, intact TFCC, and present DIOM. CONCLUSION: DRUJ instability is closely associated with TFCC, DIOM, and PQ. It could provide a potential for early detection of potential instability risk and taking necessary preventive measures.

Ulnar positive variance associated with TFCC foveal tear.

OBJECTIVE: The ulnar positive variance (UPV) can be observed on simple radiography due to a triangular fibrocartilage complex (TFCC) foveal tear. This study investigated to identify how much radiographic UPV occurs due to a TFCC foveal tear, which may be misdiagnosed as an ulnar impaction syndrome (UIS). MATERIALS AND METHODS: One hundred forty patients who underwent arthroscopic transosseus TFCC foveal repair from March 2013 to March 2019 in our institution were enrolled in this study. Ulnar variances were measured in preoperative, postoperative 6 weeks, 1-year follow-up wrist posteroanterior (PA) radiograph, and power grip PA radiograph of the affected wrist and were compared with those of the same patient's unaffected wrist. RESULTS: In the neutral wrist PA radiograph, ulnar variance increased by 0.56 mm (p < 0.001) after TFCC foveal tear compared to the unaffected side. In the power grip view, ulnar variance also increased by 0.39 mm (p < 0.001) in the affected wrist. The preoperative ulnar positive variance was reduced after an arthroscopic transosseous TFCC foveal repair from 0.56 to 0 mm (p < 0.001). No significant statistical difference was observed between an Atzei class 2 and 3 TFCC tear (0.56 mm vs. 0.41 mm, p = 0.263). CONCLUSION: This study revealed that TFCC foveal tear induces 0.56 mm of radiologic UPV, which was successfully corrected after arthroscopic transosseous TFCC foveal repair. Therefore, UPV associated with TFCC foveal tear should not be misdiagnosed as an UIS. Also, when ulnar shortening osteotomy is planned in case of UIS combined with TFCC foveal tear, the amount of UPV induced by TFCC foveal tear should be considered to prevent over-shortening.

Extensor carpi ulnaris tendon pathology and ulnar styloid bone marrow edema as diagnostic markers of peripheral triangular fibrocartilage complex tears on wrist MRI: a case-control study.

OBJECTIVES: To evaluate extensor carpi ulnaris (ECU) tendon pathology and ulnar styloid process bone marrow edema (BME) as diagnostic MRI markers for peripheral triangular fibrocartilage complex (TFCC) tears. METHODS: One hundred thirty-three patients (age range 21-75, 68 females) with wrist 1.5-T MRI and arthroscopy were included in this retrospective case-control study. The presence of TFCC tears (no tear, central perforation, or peripheral tear), ECU pathology (tenosynovitis, tendinosis, tear or subluxation), and BME at the ulnar styloid process were determined on MRI and correlated with arthroscopy. Cross-tabulation with chi-square tests, binary logistic regression with odds ratios (OR), and sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were used to describe diagnostic efficacy. RESULTS: On arthroscopy, 46 cases with no TFCC tear, 34 cases with central perforations, and 53 cases with peripheral TFCC tears were identified. ECU pathology was seen in 19.6% (9/46) of patients with no TFCC tears, in 11.8% (4/34) with central perforations and in 84.9% (45/53) with peripheral TFCC tears (p < 0.001); the respective numbers for BME were 21.7% (10/46), 23.5% (8/34), and 88.7% (47/53) (p < 0.001). Binary regression analysis showed additional value from ECU pathology and BME in predicting peripheral TFCC tears. The combined approach with direct MRI evaluation and both ECU pathology and BME yielded a 100% positive predictive value for peripheral TFCC tear as compared to 89% with direct evaluation alone. CONCLUSIONS: ECU pathology and ulnar styloid BME are highly associated with peripheral TFCC tears and can be used as secondary signs to diagnose tears. KEY POINTS: • ECU pathology and ulnar styloid BME are highly associated with peripheral TFCC tears and can be used as secondary signs to confirm the presence of TFCC tears. • If there is a peripheral TFCC tear on direct MRI evaluation and in addition both ECU pathology and BME on MRI, the positive predictive value is 100% that there will be a tear on arthroscopy compared to 89% with direct evaluation alone. • If there is no peripheral TFCC tear on direct evaluation and neither ECU pathology nor BME on MRI, the negative predictive value is 98% that there will be no tear on arthroscopy compared to 94% with direct evaluation alone.

Structurally intact and functionally incompetent foveal triangular fibrocartilage complex injuries : an under-recognized spectrum of injury.

Injury to the triangular fibrocartilage complex (TFCC) may result in ulnar wrist pain with or without instability. One component of the TFCC, the radioulnar ligaments, serve as the primary soft-tissue stabilizer of the distal radioulnar joint (DRUJ). Tears or avulsions of its proximal, foveal attachment are thought to be associated with instability of the DRUJ, most noticed during loaded pronosupination. In the absence of detectable instability, injury of the foveal insertion of the radioulnar ligaments may be overlooked. While advanced imaging techniques such as MRI and radiocarpal arthroscopy are well-suited for diagnosing central and distal TFCC tears, partial and complete foveal tears without instability may be missed without a high degree of suspicion. While technically challenging, DRUJ arthroscopy provides the most accurate method of detecting foveal abnormalities. In this annotation the spectrum of foveal injuries is discussed and a modified classification scheme is proposed.Cite this article: Bone Joint J 2023;105-B(1):5-10.

Distal Radioulnar Joint: Normal Anatomy, Imaging of Common Disorders, and Injury Classification.

The distal radioulnar joint (DRUJ) is the distal articulation between the radius and ulna, acting as a major weight-bearing joint at the wrist and distributing forces across the forearm bones. The articulating surfaces are the radial sigmoid notch and ulnar head, while the ulnar fovea serves as a critical attachment site for multiple capsuloligamentous structures. The DRUJ is an inherently unstable joint, relying heavily on intrinsic and extrinsic soft-tissue stabilizers. The triangular fibrocartilage complex (TFCC) is the chief stabilizer, composed of the central disk, distal radioulnar ligaments, ulnocarpal ligaments, extensor carpi ulnaris tendon subsheath, and ulnomeniscal homologue. TFCC lesions are traditionally classified into traumatic or degenerative on the basis of the Palmer classification. The novel Atzei classification is promising, correlating clinical, radiologic, and arthroscopic findings while providing a therapeutic algorithm. The interosseous membrane and pronator quadratus are extrinsic stabilizers that offer a minor contribution to the joint's stability in conjunction with the joints of the wrist and elbow. Traumatic and overuse or degenerative disorders are the most common causes of DRUJ dysfunction, although inflammatory and developmental abnormalities also occur. Radiography and CT are used to evaluate the integrity of the osseous constituents and joint alignment. US is a useful screening tool for synovitis in the setting of TFCC tears and offers dynamic capabilities for detecting tendon instability. MRI allows simultaneous osseous and soft-tissue evaluation and is not operator dependent. Arthrographic CT or MRI provides a more detailed assessment of the TFCC, which aids in treatment and surgical decision making. The authors review the pertinent anatomy and imaging considerations and illustrate common disorders affecting the DRUJ. Online supplemental material is available for this article. © RSNA, 2022.

Do triangular fibrocartilage complex foveal injuries affect the clinical outcome of ulnar shortening osteotomy for ulnar impaction syndrome?

BACKGROUND: Ulnar shortening osteotomy (USO), as its name implies, is used to shorten the ulna. It subsequently tightens the triangular fibrocartilage complex (TFCC) and ulnar wrist. TFCC foveal insertion is a primary stabilizer of the distal radioulnar joint. It is unclear whether USO is effective in TFCC foveal injuries. The purpose of this study was to review the clinical outcomes of ulnar shortening osteotomies with and without TFCC foveal injuries. METHODS: We retrospectively reviewed patients with ulnar wrist pain treated with USO and wrist arthroscopy including the distal radioulnar joint (DRUJ). Sixty-five patients were included in this study. An algorithm was used to guide surgical decision-making. After arthroscopic confirmation of ulnar impaction syndrome, we performed USO with a locking compression plate (mean length of shortening, 2.7 mm; range, 1-7.5 mm). The flattened TFCC disc due to ulnar shortening was confirmed arthroscopically. If the DRUJ was unstable after USO, we repaired the TFCC foveal insertion. RESULTS: There were 32 post-traumatic and 33 idiopathic cases. We detected TFCC disc injuries in 34 wrists and TFCC foveal injuries in 33 wrists; both types were found in 15 wrists. TFCC foveal injuries were not significantly correlated with patient age, history of trauma, or clinical outcome. Most patients showed good clinical outcomes; 31 of 65 patients had preoperative DRUJ instability, with a significant number having foveal but not disc injuries. CONCLUSION: USO achieved reasonable outcomes, even in patients with TFCC foveal injuries. In cases demonstrating ulnar impaction, USO should be prioritized over TFCC repair.

COMPARATIVE RADIOLOGICAL DIAGNOSTICS OF ACUTE TRIANGULAR FIBROCARTILAGE COMPLEX INJURIES.

The aim was to analyze patients with clinical diagnosis of triangular fibrocartilage complex (TFCC) lesion using standard x-ray, ultrasound, conventional magnetic resonance imaging (MRI) and MR arthrography (MRA); to evaluate the accuracy of MRA compared with MRI in the diagnosis of this lesion; and to evaluate ultrasound as a method of diagnosing TFCC lesion. We analyzed 72 patients (46 female and 26 male; age range, 22-61 years; mean age 37 years; 50 right and 22 left wrists) with suspected TFCC lesion with clinical examination, standard x-rays, and ultrasound. We confirmed patients with traumatic TFCC injury on MRI and MRA. Ultrasound found 13 lesions in 72 patients with suspected TFCC lesions. Conventional MRI found 66 and MRA 68 TFCC lesions. Ultrasound is useful for visualizing intra-articular effusion, soft tissue, bone surface, and for early detection of occult fractures. MRI is a better diagnostic modality, fully able to visualize the TFCC cartilage and ligaments. MRA is consistently and accurately able to visualize structural abnormalities of TFCC.

Motion Analysis of the Extensor Carpi Ulnaris in Triangular Fibrocartilage Complex Injury Using Ultrasonography Images.

The subsheath of the extensor carpi ulnaris (ECU) tendon, a component of the triangular fibrocartilage complex (TFCC), is particularly important as it dynamically stabilizes the distal radioulnar joint. However, the relationship between TFCC injury and ECU dynamics remains unclear. This study aimed to analyze ECU movement and morphology using ultrasonography (US) images. Twenty wrists of patients with TFCC injury, who underwent TFCC repair, were included in the injury group, and 20 wrists of healthy volunteers were in the control group. For static image analysis, curvature and linearity ratios of the ECU in US long-axis images captured during radioulnar deviation were analyzed. For dynamic analysis of the ECU, the wrist was moved from radial deviation to ulnar deviation at a constant speed, and the velocity of the tendon was analyzed using particle image velocimetry. The static analysis showed that the ECU tendon was more curved in ulnar deviation in the injury group than in the control group, and the dynamic analysis showed that only vertical velocity toward the deep side during ulnar deviation was higher in the injury group. These results suggest that TFCC injury caused ECU curvature during ulnar deviation and increased the vertical velocity of the ECU during wrist deviation.

Differentialtherapeutische Zugänge zum distalen Radioulnargelenk und zur distalen Ulna.

At the distal radioulnar joint (DRUJ) and the ulnocarpal joint several anatomical structures are in a limited space. Therefore, the operative approach has to consider the pathology to be treated. The DRUJ may be approached from the dorsal or the palmar side. Procedures to treat the arthrotically destroyed DRUJ involving bone resection of the ulnar head and destabilizing ligamentous injuries of the triangular fibrocartilage complex (TFCC) are best approached from the dorsal side. This approach allows excellent visualization of the ulnar head and the ulnar and radial attachment of the TFCC. The arthroscopic, half open refixation of the ulnar avulsion of the TFCC may be performed using a variety of limited and small approaches over the dorsal or lateral ulnar head. Pathologies with an origin at the palmar aspect of the DRUJ as the palmar dislocation of the ulnar head in the DRUJ or the shrinkage and scaring of the palmar capsule with consecutive pronation contracture require a palmar approach. Reduction and osteosynthesis of fractures in the area of the ulnar head are preformed using a lateral approach along the styloid process and the ulnar head between the flexor and the extensor carpi ulnaris tendons. Along the ulnar shaft elective ulnar shortening osteotomy as well as fracture reduction and osteosynthesis are best performed from an ulno palmar approach.

Reconstruction of Triangular Fibrocartilage Complex Avulsions (Palmar 1C) with Associated Lunotriquetral and Dorsal Capsule Injury: A Case Report.

CASE: A 34-year-old farmer and railroad worker injured his left wrist when working at a railroad. The resulting dorsal-ulnar wrist blow caused disabling pain. Splits and 2 subsequent surgeries failed, including an arthroscopic triangular fibrocartilage complex (TFCC) debridement and thermal ablation. Subsequently, magnetic resonance imaging documented a rare Palmer type 1C distal TFCC avulsion. Function was restored and return to farming permitted by reconstruction of the ulnotriquetral (UT) ligament using an extensor carpi ulnaris (ECU) slip. CONCLUSION: Chronic Palmer type 1C TFCC injuries can be successfully treated with ECU reconstruction of the UT ligament.

Design and Performance Analysis of a Dynamic Magnetic Resonance Imaging-Compatible Device for Triangular Fibrocartilage Complex Injury Diagnosis.

Pain and injury of the triangular fibrocartilage complex (TFCC) due to overuse or trauma are commonly diagnosed through static MRI scanning, while TFCC is always involved in radial and ulnar deviation of the wrist. To the best of our knowledge, a dynamic MRI diagnostic method and auxiliary tool have not been applied or fully developed in the literature. As such, this study presents the design and evaluation of a dynamic magnetic resonance imaging (MRI) auxiliary tool for TFCC injury diagnosis. First, 3D scanning and Python are used to measure and fit the radial and ulnar deviation trajectories of healthy participants and patients. 3D printing is then used to manufacture the auxiliary tool for dynamic MRI, and dynamic MRI diagnosis is then conducted to explore the clinical effect. The radial and ulnar deviation trajectory is presented as an asymmetric curve without an obvious circular centre, and the results indicate that the designed auxiliary device meets the requirements of the ulnar and radial movements of the human wrist. According to the MRI contrast test results, the image quality score of patients wearing the auxiliary device is higher than for those without. Such devices could assist clinicians in the diagnosis of TFCC damage, and our method could not only serve as the reference standard for clinical noninvasive diagnosis but also help in understanding the disease and improving the accuracy of TFCC diagnosis.

Ulnar variance and triangular fibrocartilage thickness in adolescents: a cross-sectional MRI study of healthy participants.

Skeletally immature wrists are considered at risk of injury due to increased axial loading through a relatively shorter ulna. The aim of this study was to determine whether triangular fibrocartilage thickness relates to ulnar variance and age in adolescents. The radiographs and MRIs of 24 healthy adolescents were retrospectively assessed. Four observers assessed bone age and ulnar variance on radiographs and measured triangular fibrocartilage thickness on MRIs. Median calendar and bone age was 13 years and ulnar variance was -0.7 mm. Median triangular fibrocartilage thickness was 1.4 mm, with excellent inter-observer agreement (r = 0.86). It was moderately correlated with ulnar variance (ρ = -0.46) as well as with bone age (ρ = -0.49). Both variables were statistically significant predictors in a multivariate analysis. This suggests that triangular fibrocartilage thickness changes during skeletal maturation, which might influence axial load distribution in skeletally immature wrists.

Load-Bearing Radioulnar Distances to Evaluate an Unstable Distal Radioulnar Joint in Patients With Triangular Fibrocartilage Complex Tears.

PURPOSE: Tears of the proximal component of the triangular fibrocartilage complex (pc-TFCC) lead to instability in the distal radioulnar joint. The aim of this study was to measure the load-bearing radioulnar distances (RaUls) and to evaluate its diagnostic suitability in patients with pc-TFCC tears. METHODS: We retrospectively assessed and compared the lateral wrist radiographs of 61 adult patients with arthroscopically confirmed tears of pc-TFCC with those of a control group of 64 healthy participants. The RaUl was measured on lateral radiographs, and the difference in RaUl (D-value) between load-bearing and nonloading conditions was calculated in the 2 groups. Receiver operator characteristic curves were plotted to determine the diagnostic accuracy and optimal cutoff-score of load-bearing RaUl and RaUl D-value. The diagnostic performance was verified in a validation sample of patients (30 wrists) with pc-TFCC tears and a control group of healthy individuals (30 wrists). RESULTS: In the training sample, load-bearing RaUls of the affected wrists were higher than the same side of the controls (12.0 mm vs 7.1 mm). The TFCC-injury group showed a significantly higher RaUl D-value than the control group (8.5 mm vs 3.4 mm). Using a receiver operator characteristic curve, the cutoff value of load-bearing RaUl was 10 mm (sensitivity = 97.6%, specificity = 85.7%) and that of RaUl D-value was 6.5 mm (sensitivity = 90.2%, specificity = 78.5%). The areas under the curve of load-bearing RaUl and RaUl D-value were 0.96 and 0.88, respectively. In the test sample, the sensitivity, specificity, and accuracy of RaUl were 0.93, 0.70, and 0.82 and those of RaUl D-value were 0.77, 0.83, and 0.80 respectively. CONCLUSIONS: Load-bearing RaUl measurement is a simple method to diagnose an unstable distal radioulnar joint in patients with TFCC injury. The load bearing RaUl of >10 mm or RaUl D-value of >6.5 mm can be used to differentiate TFCC injuries and showed acceptable accuracy. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic II.

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

PURPOSE: To evaluate the optimal sequence for high-resolution magnetic resonance imaging (MRI) of the triangular fibrocartilage complex (TFCC) using compressed sensing-sensitivity encoding (CS-SENSE). METHODS: Three-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. RESULTS: The 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. CONCLUSIONS: Out 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.

Motion Analysis of Triangular Fibrocartilage Complex by Using Ultrasonography Images: Preliminary Analysis.

The triangular fibrocartilage complex (TFCC) is a significant stabilizer of the distal radioulnar joint. Diagnosing TFCC injury is currently difficult, but ultrasonography (US) has emerged as a low-cost, minimally invasive diagnostic tool. We aimed to quantitatively analyze TFCC by performing motion analysis by using US. Twelve healthy volunteers, comprising 24 wrists (control group), and 15 patients with TFCC Palmer type 1B injuries (injury group) participated. The US transducer was positioned between the ulnar styloid process and triquetrum and was tilted ulnarly 30° from the vertical line. The wrist was then actively moved from 10° of radial deviation to 20° of ulnar deviation in a 60-rounds-per-minute rhythm that was paced by a metronome. The articular disc displacement velocity magnitude was analyzed by using particle image velocimetry fluid measurement software. The mean area of the articular discs was larger on ulnar deviation in the control group. The mean articular disc area on radial deviation was larger in the injury group. The average articular disc velocity magnitude for the injury group was significantly higher than that for the control group. The results suggest that patients with TFCC injury lose articular disc cushioning and static stability, and subsequent abnormal motion can be analyzed by using US.

Diagnostic accuracy of wrist MRI in comparison to wrist arthroscopy regarding TFCC lesions in clinical practice.

INTRODUCTION: The purpose of this study was to arthroscopically verify MRI diagnostic accuracy for triangular fibrocartilage complex (TFCC) lesions in a regular clinical environment. METHODS: A total of 859 patients' data with both preoperative MRI of the wrist and additional wrist arthroscopy were retrospectively reviewed. Two board-certified hand surgeons and one orthopaedic surgeon executed wrist arthroscopy, whereas more than 100 radiologists examined the MRI of the wrist. The accordance of TFCC lesion classification using MRI in comparison to wrist arthroscopy and diagnostic precision of the former depending on technical details were evaluated. RESULTS: Diagnostic accuracy of MRI for TFCC lesions is poor in comparison to wrist arthroscopy as the reference standard. Technical specifications for MRI of the wrist are heterogeneous among the radiologists. These parameters have not improved accuracy of TFCC evaluation at large. CONCLUSION: The accuracy of MRI in a regular clinical environment still remains inferior to wrist arthroscopy for detection of TFCC lesions. Development of a standard MRI protocol may be implemented on a regular basis and application of the Palmer classification for TFCC lesion should be sought.