Acute blockage of forearm supination due to flap tear of the triangular fibrocartilage disc: A case report

RATIONALE

Acute blockage of forearm supination has been reported in several studies. It is caused by loose bodies in the wrist joint, extensor carpi ulnaris tendon interposition, and distal radioulnar joint (DRUJ) injuries, including forearm bone fractures. Some studies have reported cases of DRUJ injuries caused by triangular fibrocartilage complex (TFCC) tears.We report a case of acute blockage of forearm supination after minor trauma and suggest a possible TFCC tear when a patient complains of forearm supination blocking. In addition, we present a comparison between our case and other reports on etiology, magnetic resonance imaging (MRI) findings, and arthroscopic findings, and show the specific characteristics of our case.

PATIENTS CONCERNS

A 22-year-old male presented with left wrist pain as the chief complaint. He was injured 2 months prior to pushing his left hand on the floor during exercise. Physical examination showed a relative limitation of range of motion (ROM) in the left wrist of about 10° in flexion and about 15° in extension compared with the right side. The patient also complained of supination limitation and volar side wrist pain during supination. The patient showed tenderness in the axial compression test.

DIAGNOSES

Plain radiographs showing no abnormalities. MRI showed a TFCC tear in the central portion. A torn flap of the TFCC was interposed on the volar side of the DRUJ.

INTERVENTIONS

Arthroscopic surgery of the left wrist joint was performed. Arthroscopic examination revealed a tear in the TFCC on the radial side. A torn flap was interposed on the volar side of the DRUJ. We removed the flap from the DRUJ using an arthroscopic grasper and partially resected it.

OUTCOMES

Intraoperative tests showed no locking and the forearm was well supinated. Two months after the surgery, the patient had no pain and showed full forearm supination.

LESSONS

DRUJ blocking due to a TFCC tear should be suspected when acute blockage of forearm supination occurs after minor trauma. MRI is helpful for diagnosis; however, we suggest that the diagnosis should be confirmed through arthroscopy. Symptoms can be resolved by surgical treatment using arthroscopy.

Biomechanical Outcomes of Surgically Repaired TFCC Palmer Type 1B Tears: A Systematic Review of Cadaver Studies

BACKGROUND

Palmer type 1B triangular fibrocartilage complex (TFCC) tears are a common cause of distal radioulnar joint (DRUJ) instability. Unfortunately, the best surgical technique for TFCC reinsertion is still unknown, and up to a quarter of patients report instability after repair. The purpose of this systematic review of cadaver studies was to compare the biomechanical outcomes of different surgical techniques used for Palmer 1B TFCC tears.

METHODS

A systemic review of all cadaver studies published before January 2022 was performed using the PubMed and EMBASE databases. Only cadaver studies on reinsertion techniques for Palmer type 1B lesions were included. Biochemical outcome parameters evaluated were stability of the DRUJ and strength of the repair.

RESULTS

A total of 248 articles were identified. Five articles fulfilled the inclusion criteria. Four different surgical techniques were identified. In 3 studies, transosseous tunnel repair was tested and resulted in the most stable DRUJ and strongest TFCC repair compared with the suture anchor repair, the peripheral capsular repair, and the outside-in repair.

CONCLUSIONS

These results suggest that the transosseous tunnel repair might be a good technique for restoring DRUJ stability. However, more cadaver studies are needed to identify the most optimal technique.

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.

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.

MR morphology of triangular fibrocartilage complex: correlation with quantitative MR and biomechanical properties

OBJECTIVE

To evaluate pathology of the triangular fibrocartilage complex (TFCC) using high-resolution morphologic magnetic resonance (MR) imaging, and compare with quantitative MR and biomechanical properties.

MATERIALS AND METHODS

Five cadaveric wrists (22-70 years) were imaged at 3 T using morphologic (proton density weighted spin echo, PD FS, and 3D spoiled gradient echo, 3D SPGR) and quantitative MR sequences to determine T2 and T1rho properties. In eight geographic regions, morphology of TFC disc and laminae were evaluated for pathology and quantitative MR values. Samples were disarticulated and biomechanical indentation testing was performed on the distal surface of the TFC disc.

RESULTS

On morphologic PD SE images, TFC disc pathology included degeneration and tears, while that of the laminae included degeneration, degeneration with superimposed tear, mucinous transformation, and globular calcification. Punctate calcifications were highly visible on 3D SPGR images and found only in pathologic regions. Disc pathology occurred more frequently in proximal regions of the disc than distal regions. Quantitative MR values were lowest in normal samples, and generally higher in pathologic regions. Biomechanical testing demonstrated an inverse relationship, with indentation modulus being high in normal regions with low MR values. The laminae studied were mostly pathologic, and additional normal samples are needed to discern quantitative changes.

CONCLUSION

These results show technical feasibility of morphologic MR, quantitative MR, and biomechanical techniques to characterize pathology of the TFCC. Quantitative MRI may be a suitable surrogate marker of soft tissue mechanical properties, and a useful adjunct to conventional morphologic MR techniques.

Palmer Classification and Magnetic Resonance Imaging Findings of Ulnocarpal Impingement

Ulnocarpal impaction (UCI) syndrome is a well-recognized and relatively frequent cause of ulnar-sided wrist pain and limitation of motion. In the setting of negative or questionable negative radiographs and a strong clinical suspicion for UCI, magnetic resonance imaging (MRI) is helpful in detecting occult disease. Current MRI technology is capable of providing high-spatial-resolution images on multiple planes while manipulating contrast to highlight different tissue types. However, imaging of the triangular fibrocartilage complex has been challenging because of the small and complex components of this structure. In this article, the stages of UCI are discussed with illustrations of the spectrum of MRI findings using Palmer classification as a guideline.

Morphology of the extensor carpi ulnaris groove and tendon

PURPOSE

Injury to the extensor carpi ulnaris (ECU) fascial supports on the distal ulna can result in ulnar-sided wrist pain, particularly when the tendon subluxates medially out of the fibroosseous groove with forearm rotation. To better understand the potential risk factors for injury and the indications for modifying the ECU groove, we have evaluated and quantified the morphology of the ECU groove and tendon.

METHODS

Axial plane magnetic resonance imaging of the wrist obtained for triangular fibrocartilage complex and intercarpal pathology in 60 patients were reviewed. Mean and standard error of the mean were calculated and unpaired Student t tests performed to compare groove width and depth, radius of curvature of the groove, carrying angle, and tendon-to-groove ratio.

RESULTS

There were 23 females (38%), and the mean patient age was 40 years (range, 17-71 y). The average ECU groove depth and standard error of the mean was 1.4 mm ± 0.1 mm. The radius of curvature for the ulnar ECU groove was found to be 7.0 mm ± 0.4 mm with a carrying angle of 143° ± 2°. In neutral forearm rotation, the average ratio of the width of the ECU tendon to groove was 0.7 ± 0.02. The data approximated a normal distribution. There were no statistically significant differences in these measurements between the triangular fibrocartilage complex and the intercarpal pathology subgroups.

CONCLUSIONS

Variability in the relationship of the ECU groove and tendon may combine to represent risk factors for tendinosis or tendon subluxation. There may be a more normal distribution of ECU groove morphology than previously recognized.

CLINICAL RELEVANCE

ECU injuries may require clinical imaging of the tendon and subsheath, in addition to potential surgical reconstruction and ulnar groove deepening. This report establishes the normative morphology and depth of the ECU groove and provides a comparative baseline when considering treatment modalities.

How does ulnar shortening osteotomy influence morphologic changes in the triangular fibrocartilage complex?

BACKGROUND

Ulnar shortening osteotomy often is indicated for treatment of injuries to the triangular fibrocartilage complex (TFCC). However, the effect of ulnar shortening osteotomy on the changes in shape of the TFCC is unclear. In our study, quantitative evaluations were performed using MRI to clarify the effect of ulnar shortening on triangular fibrocartilage (TFC) thickness attributable to disc regeneration of the TFC and TFC angle attributable to the suspension effect of ulnar shortening on the TFC.

QUESTIONS/PURPOSES

The purposes of this study were (1) to compare preoperative and postoperative TFC thickness and TFC angle on MR images to quantitatively evaluate the effect of ulnar shortening osteotomy on disc regeneration and the suspension effect on the TFC; and (2) to assess whether changes in TFC thickness and TFC angle correlated with the Mayo wrist score.

METHODS

Between 1995 and 2008, 256 patients underwent ulnar shortening osteotomy for TFCC injuries. The minimum followup was 24 months (mean, 51 months; range, 24-210 months). A total of 79 patients (31%) with complete followup including preoperative and postoperative MR images and the Mayo wrist score was included in this retrospective study. Evaluation of the postoperative MR images and the Mayo wrist score were performed at the final followup. The remaining 177 patients did not undergo postoperative MRI, or they had a previous fracture, large tears of the disc proper, or were lost to followup. Two orthopaedists, one of whom performed the surgeries, measured the TFC thickness and the TFC angle on coronal MR images before and after surgery for each patient. Correlations of the percent change in the TFC thickness and the magnitude of TFC angle change with age, sex, postoperative MR images, extent of ulnar shortening, preoperative ulnar variance, and postoperative Mayo wrist score were assessed.

RESULTS

Stepwise regression analysis showed a correlation between the percent change in TFC thickness and preoperative ulnar variance (R2=0.21; β=-0.33; 95% CI, -0.11 to 0.01; p=0.01) and between the magnitude of change in the TFC angle and the extent of ulnar shortening (R2=0.18; β=-0.29; 95% CI, -5.8 to 0.29; p=0.03). The Mayo wrist score was not correlated with the percent change in TFC thickness or the magnitude of change in the TFC angle.

CONCLUSIONS

These results suggest that, in patients with TFCC injury with a smaller preoperative ulnar variance, a high residual potential for regeneration in the disc proper was seen after ulnar shortening osteotomy, and correlated with the extent of ulnar shortening and the suspension effect on TFC. However, there was no correlation between disc regeneration or the suspension effect on TFC and the Mayo wrist score.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.

Nerve fiber staining investigations in traumatic and degenerative disc lesions of the wrist

PURPOSE

Traumatic and degenerative disc lesions cause ulnar-sided wrist pain. To date, anatomical investigations of cadaver triangular fibrocartilage discs examining the innervation of the triangular fibrocartilage complex have found no evidence of nerve fibers in the healthy disc. In this study, we immunohistologically investigated biopsies from patients with either central traumatic or degenerative disc lesions, to determine the existence of nerve fibers. We hypothesized that an ingrowth of nerve fibers causes ulnar-sided wrist pain associated with traumatic and degenerative disc lesions.

METHODS

We included 32 patients with a traumatic Palmer 1A lesion and 17 patients with a degenerative Palmer 2C lesion in the study. We obtained a biopsy of each patient and stained the specimen with protein gene product 9.5 for nerve fiber detection.

RESULTS

There were no nerve fibers in either traumatic or degenerative disc lesions. In addition, the marginal areas of the biopsies showed no evidence of nerve fibers.

CONCLUSIONS

Traumatic and degenerative disc lesions show no ingrowth of nerve fibers.

Sonography and sonoarthrography of the scapholunate and lunotriquetral ligaments and triangular fibrocartilage disk: initial experience and correlation with arthrography and magnetic resonance arthrography

OBJECTIVE

The purpose of this study was to determine the utility of sonography and sonoarthrography in evaluation of dorsal bands of the scapholunate ligament (SLL), lunotriquetral ligament (LTL), and triangular fibrocartilage (TFC) disk in correlation with arthrography and magnetic resonance arthrography (MRA).

METHODS

High-resolution sonography of the SLL, LTL, and TFC disk was performed on symptomatic wrists in 16 patients referred by a hand surgeon for MRA of the symptomatic wrists. All patients then underwent arthrography and an MRA study of the same wrist. After MRA, sonography was repeated. The imaging findings of these different techniques were then compared. Four patients (25%) underwent surgery of their wrists. In these 4 patients, the surgical and imaging findings were correlated.

RESULTS

For the SLL, the results were concordant for all imaging modalities in 15 patients (93.75%) and partially concordant in 1 (6.25%). For the LTL, the results were concordant for all imaging modalities in 12 patients (75%), partially concordant in 3 (18.75%), and discordant in 1 (6.25%). For the TFC disk, the results were concordant for all imaging modalities in 13 patients (81.25%), partially concordant in 2 (12.5%), and discordant in 1 (6.25%). The arthroscopic and imaging findings were concordant for 3 SLLs, 3 LTLs, and 3 TFC disks.

CONCLUSIONS

Our preliminary results are encouraging. Sonography may be used at least as a screening imaging modality in evaluation of the SLL and TFC disk. Sonoarthrography improves evaluation of the LTL.

Study of ulnar variance with high-resolution MRI: correlation with triangular fibrocartilage complex and cartilage of ulnar side of wrist

PURPOSE

To investigate correlations with ulnar variance and the triangular fibrocartilage complex (TFCC) or cartilage of ulnar side of the wrist on high-resolution MRI with a microscopy coil.

MATERIALS AND METHODS

We reviewed ulnar variance, TFCC, and cartilage of the ulnar side of the wrist in 93 subjects (29 asymptomatic volunteers and 64 patients with suspected TFCC injury) with high-resolution MRI using a 47-mm microscopy surface coil. All MR images were obtained with a 1.5 T scanner. Coronal 2D gradient recalled echo T(2)*-weighted images were used for analysis. For qualitative analysis we measured ulnar variance, TFCC angle, thickness in the central portion of TFCC disc proper, and cartilage thickness of the lunate and the ulnar head on MRI and calculated the correlation coefficient between measured values. We also examined the relationship between ulnar variance and age or sex.

RESULTS

High-resolution MR images clearly demonstrated TFCC and cartilage of the wrist and ulnar variance. The mean ulnar variance on MRI was +0.26 mm (range, -4.59 to +3.71 mm). The mean TFCC angle and TFCC thickness were 23.9 degrees (range, -4.6 to +54.1 degrees ) and 1.11 mm (range, 0.4 to 3.22 mm), respectively. Ulnar variance and TFCC angle were positively correlated (r = 0.84), and ulnar variance and TFCC thickness were negatively correlated (r = -0.71). However, ulnar variance and lunate or ulnar head cartilage thickness were not significantly correlated.

CONCLUSION

High-resolution MRI with a microscopy coil is a useful tool for evaluating the relationship between ulnar variance and ulnar side structures.

Detection of apoptotic cartilage cells in symptomatic central tears of the triangular fibrocartilage

PURPOSE

Central traumatic injuries of the triangular fibrocartilage are frequent sources of ulnar wrist pain. It is unknown whether the fibrocartilage cells survive this trauma in the central part of the triangular fibrocartilage. The goal of this study was to determine the viability of cells in traumatic triangular fibrocartilage complex (TFCC) Palmer 1A lesions to estimate the role of apoptosis for the fate of fibrocartilage cells.

METHODS

Twenty-two patients with a symptomatic central traumatic tear in the triangular fibrocartilage were included in this study. The cartilage was debrided arthroscopically, and histologic sections were used for the analysis of cell viability and apoptosis. Cell viability was quantified by terminal deoxyribonucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay, and apoptotic cells were visualized by poly(ADP-ribose) polymerase (PARP) p85 immunohistochemistry. The number of apoptotic cells was correlated with the total number of cells.

RESULTS

In contrast with the control patients with only minimal amounts of TUNEL-positive cells, cell viability was markedly reduced in all analyzed patients with TFCC Palmer 1A lesion. Likewise, the number of PARP p85-positive cells was significantly increased in all patients. This indicates that the observed cell death is attributed to apoptosis. Concerning the distribution of apoptotic cells, the inner zone of the biospy showed much higher numbers of apoptotic cells than the outer zone in both PARP and TUNEL staining. In contrast to the analyzed patients, no apoptosis could be detected in the controls.

CONCLUSIONS

High amounts of apoptotic cartilage cells could be detected within the inner part of the triangular fibrocartilage suggesting that fibrocartilage cells died in response to trauma and were not quickly replaced by new viable cells. PARP p85-positive cells indicate that the apoptotic cascade plays a crucial role in the TFCC Palmer 1A disorder.

Evaluation of the triangular fibrocartilage in cadaveric wrists by means of arthrography, magnetic resonance (MR) imaging, and MR arthrography

PURPOSE

To evaluate the diagnostic accuracy of arthrography, magnetic resonance (MR) imaging, and MR arthrography in the detection and localization of defects of the triangular fibrocartilage (TFC) in cadaveric wrists, using arthroscopy as a reference standard.

MATERIAL AND METHODS

Twenty-four specimen wrists were evaluated. The different imaging modalities were blinded to reviewers and were interpreted independently. A classification of TFC defects was used for the evaluation of images in the different imaging modalities, thus permitting a more uniform correlation. Two cases were excluded from the MR imaging study because of poor image quality. Contingency tables with the chi-square test and Fisher's exact test were used for statistical analysis.

RESULTS

Defects of the TFC were identified in 17 of the 24 specimen wrists by means of arthroscopy, and 16 defects were observed when arthrography was carried out. With MR imaging 14 defects of the TFC were detected in the 22 specimen wrists evaluated, and with MR arthrography 16 defects were observed. Most defects were central or combined (two or more defects). In comparison to arthroscopy, the accepted diagnostic gold standard, the following results were found for arthrography in the detection of TFC defects: sensitivity 95%, specificity 100%, and accuracy 95% (P<0.0005); for MR imaging: sensitivity 86%, specificity 85%, and accuracy 70% (P<0.002); and for MR arthrography: sensitivity 100%, specificity 85%, and accuracy 95% (P<0.0005).

CONCLUSION

The results of the study seem to indicate that both arthrography and MR arthrography have high accuracy, and either would be useful for evaluation of the TFC. The combined approach using both techniques would have a very high accuracy equivalent to that resulting from arthroscopy.

Peripheral tear of the triangular fibrocartilage: depiction with MR arthrography of the distal radioulnar joint

OBJECTIVE

Although central tears of the triangular fibrocartilage are easily seen on imaging, peripheral tears of the ulnar attachment are frequently missed. The aim of this study was to evaluate the accuracy of MR arthrography of the distal radioulnar joint in depiction of peripheral tears of the triangular fibrocartilage.

MATERIALS AND METHODS

Forty-one patients (18 women, 23 men; mean age, 38 years; age range, 18-60 years) underwent MR arthrography and wrist arthroscopy. For MR arthrography, iopamidol (300 mg I/mL) and gadopentetate dimeglumine (4 mmol/L) were injected into the distal radioulnar joint. Consensus review of both MR arthrograms and conventional arthrograms was performed by two experienced musculoskeletal radiologists. Presence or absence of communicating and noncommunicating tears of the ulnar attachment of the triangular fibrocartilage was recorded. Arthroscopy was used as the standard of reference for determining sensitivity, specificity, and accuracy in detection of tears of the ulnar attachment.

RESULTS

At MR arthrography, communicating tear of the ulnar attachment was diagnosed in three patients, noncommunicating tear in 19 patients, and normal attachment in 19 patients. Arthroscopy revealed peripheral tear of the triangular fibrocartilage in all three patients with communicating tear, in 14 of 19 patients with noncommunicating tear, and in three of 19 patients with normal attachment. The sensitivity was 85% (17/20), specificity was 76% (16/21), and accuracy was 80% (33/41).

CONCLUSION

MR arthrography of the distal radioulnar joint is accurate in depiction of peripheral tears of the ulnar attachment of the triangular fibrocartilage. These tears often appear as noncommunicating tears extending from the distal radioulnar joint into the triangular fibrocartilage.

High-resolution MRI of the triangular fibrocartilage complex (TFCC) at 3T: Comparison of surface coil and volume coil

PURPOSE

To evaluate high-resolution MRI of the triangular fibrocartilage complex (TFCC) at 3T using a surface coil (SC) or volume coil (VC).

MATERIALS AND METHODS

MRI was obtained from nine volunteers in the supine position with a 3-inch SC and in prone position with a transmit-receiver wrist VC at 3 T. Coronal two-dimensional-gradient echo (2D-GRE) images (TR/TE/FA = 500 msec/15 msec/40 degrees , 1 mm slice-thickness, 60 mm field of view [FOV], 192 x 256 matrix) and coronal 3D-GRE images (TR/TE/FA = 33 msec/15 msec/10 degrees , 0.8 mm slice-thickness, 80 mm FOV, 256 x 256 matrix) were used. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the TFCC and surrounding structures were measured. For qualitative measurement, visualization of TFCC and intercarpal ligaments was graded.

RESULTS

SNR of TFCC, cartilage, and bone marrow on 2D-GRE with SC/VC was as follows: 5.3/5.3 (TFCC), 16.5/14.4 (cartilage), and 3.61/3.96 (bone marrow). 3D-GRE showed similar SNR. Cartilage-TFCC/cartilage-bone marrow CNR were 11.1/12.8 (SC-2D-GRE), 8.8/10.5 (VC-2D-GRE), 14.1/15.5 (SC-3D-GRE), and 11.9/15.0 (VC-3D-GRE). Quantitative values were not significantly different between SC and VC. Visualization of TFCC and intercarpal ligament with SC was superior to that with VC. All structures show higher scores with 3D-GRE imaging compared to 2D-GRE imaging.

CONCLUSION

SC may provide superior qualitative and quantitative results and can be an alternative in case of difficulty in prone position at 3T.

Comparison between high-resolution MRI with a microscopy coil and arthroscopy in triangular fibrocartilage complex injury

PURPOSE

To determine whether high-resolution magnetic resonance imaging (MRI) could detect injuries to the triangular fibrocartilage complex (TFCC).

METHODS

Eleven patients who showed both a positive sign during the ulnocarpal stress test and tenderness at the distal end of the ulna had a high-resolution MRI using a 47-mm diameter microscopy coil. Six regions of the TFCC were investigated for injury: the radial attachment, disc, ulnar attachment of the triangular fibrocartilage (TFC), ulnotriquetral ligament, palmar radioulnar ligament (PRUL), and dorsal radioulnar ligament (DRUL). Arthroscopy was performed subsequently on each patient.

RESULTS

For injuries to the radial attachment or the disc of the TFC, a high-resolution MRI showed 100% sensitivity and 100% specificity compared with arthroscopy. In 3 cases in which injury to the ulnar attachment of the TFC was detected with MRI and examination showed a positive piano-key sign and distal radioulnar joint instability, only 1 injury was confirmed with arthrotomy. For MRI diagnosis of an ulnotriquetral ulnolunate attachment injury, the sensitivity was 100% and the specificity was 70%; however, 3 cases had false-positive results. Finally MRI had 100% sensitivity for detecting DRUL and PRUL injuries, although specificities were 75% and 83%, respectively. With MRI there were 2 false-positive DRUL injury diagnoses and 1 false-positive PRUL injury diagnosis.

CONCLUSIONS

High-resolution MRI using a microscopy surface coil allowed assessment of each TFCC component and showed a higher accuracy for diagnosing injuries to the radial attachment and the disc of the TFC compared with previous studies. High-resolution MRI, however, was not able to diagnose DRUL, PRUL, or ulnolunate ligament injuries accurately.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic III.