Wertigkeit der MRT hinsichtlich TFCC-Läsionen außerhalb klinischer Studien

Wrist arthroscopy for diagnosis and treatment of acute and chronic conditions

Wrist arthroscopy is a constantly evolving procedure. Allowing direct visualization and dynamic testing of intra-articular structures led to a novel approach toward traumatic and degenerative lesions based on most of the classifications routinely used in wrist surgery. The development of specific instrumentation, combined with a novel understanding of the local anatomy, progressively allowed wrist surgeons to describe more ambitious and complex surgeries. Wrist arthroscopy has become an increasingly useful tool in hand and wrist surgeons' panoply and seems promised to have further development in the future. This paper discusses the surgical technique and the various pathologies that can be treated by arthroscopy of the wrist.

Visualization of wrist ligaments with 3D and 2D magnetic resonance imaging at 3 Tesla

BACKGROUND

Wrist ligaments are challenging to visualize using magnetic resonance imaging (MRI). Injuries involving the scapholunate ligament (SLL), the lunotriquetral ligament (LTL), and the triangular fibrocartilage complex (TFCC) are common and difficult to diagnose, often requiring diagnostic arthroscopy.

PURPOSE

To compare the visualization of wrist ligaments on a three-dimensional (3D) sequence with two-dimensional (2D) sequences on 3-T MRI.

MATERIAL AND METHODS

Eighteen healthy volunteers were examined with a 3D SPACE (sampling perfection with application optimized contrasts using different flip angle evolution) sequence and 2D coronal, axial, and sagittal proton density-weighted (PD) sequences. Four musculoskeletal radiologists graded the anatomical visibility of the SLL, LTL, TFCC, and the image quality, using five grades in a visual grading characteristics (VGC) evaluation. After Bonferroni correction, a P value ≤0.005 was considered statistically significant.

RESULTS

The 3D images were graded significantly better than the 2D images in the visualization of the dorsal and palmar parts of the SLL and the LTL. Regarding the TFCC, the 3D images were graded significantly better for visualization of the foveal attachment. 2D imaging was not found significantly superior to 3D imaging in any aspect.

CONCLUSION

The 3D SPACE sequence was scored as superior to the 2D sequences at 3 T in the assessment of the SLL, the LTL, and the foveal attachment of the TFCC. Thus, 3D SPACE can replace 2D PD sequences when these ligaments need to be assessed.

Visualization of wrist anatomy-a comparison between 7T and 3T MRI

OBJECTIVE

Injuries to the wrist are, due to its small size and complex anatomical structures, difficult to assess by MR, and surgical interventions such as diagnostic arthroscopy are often necessary. Therefore, improved visualization using non-invasive methods could be of clinical value. As a first step of improvement, the purpose of this study was to evaluate visualization of anatomical structures at 7T compared with 3T MR.

METHODS

Eighteen healthy volunteers (three males and three females from each age decade between 20 and 49 years) were examined with 7T and 3T MR. Four musculoskeletal radiologists graded 2D and 3D images on a five-level grading scale for visibility of ligaments, cartilage, nerves, trabecular bone, and tendons, as well as overall image quality (i.e., edge sharpness, perceived tissue contrast, and presence of artefacts). Statistical analysis was done using a visual grading characteristics (VGC) analysis.

RESULTS

Visibility of cartilage, trabecular bone, tendons, nerves, and ligaments was graded significantly higher at 7T with an area under the curve (AUC_VGC) of 0.62-0.88 (95% confidence interval [CI] 0.50-0.97, p = < 0.0001-0.03) using either 2D or 3D imaging. Imaging with 3T was not graded as superior to 7T for any structure. Image quality was also significantly superior at 7T, except for artefacts, where no significant differences were found.

CONCLUSIONS

Tendons, trabecular bone, nerves, and ligaments were all significantly better visualized at 7T compared to 3T.

KEY POINTS

• MRI of the wrist at 7T with a commercially available wrist coil is feasible at similar acquisition times as for 3T MRI. • The current study showed 7T to be superior to 3T in the visualization of anatomical structures of the wrist, including ligaments, tendons, nerves, and trabecular bone. • Image quality was significantly superior at 7T, except for artefacts, where no significant differences were found.

[Radiology of the distal radioulnar joint and the ulnocarpal complex]

X-ray images exposed in neutral position and radiocarpally centred are essential in imaging of the distal radioulnar joint (DRUJ). The anatomic orientation of the DRUJ is favourable for acquiring transaxial scans to display its anatomy, subtle derangements, osteoarthritis and intra-articular fractures free from superpositions. The triangular fibrocartilage complex (TFCC) is the most important stabilizer of the DRUJ. Provided that a focused clinical indication is given, high-resolution images are acquired, and an intra-venous or intra-articular contrast-agent is applied, all TFCC structures and destabilizing lesions can be displayed with the use of CT and MRI.

[Diagnosis and treatment of degenerative disc lesions of the wrist]

BACKGROUND

The triangular fibrocartilage complex (TFCC) widens the radiocarpal joint and takes part in load transmission from the carpus to the forearm. It is thereby prone to degenerative changes. The painful situation that can accompany degeneration is called ulnar impaction.

DIAGNOSIS

Clinical examination helps differentiate between various causes of ulnar-sided wrist pain. Standard X‑rays are needed to determine ulnar variance and stress radiographs can depict narrowing of the ulnocarpal joint space under load. MRI may prove degeneration of the TFCC itself or may indirectly confirm ulnar impaction in the presence of bone marrow edema in the ulnar head or at the proximal ulnar aspect of the lunate.

TREATMENT

If conservative treatment fails to alleviate symptoms, arthroscopy may be indicated. On the one hand, this completes the diagnostic cascade, and, on the other hand, allows decompression of the ulnocarpal joint space by resection of the TFCC with partial resection of the ulnar head (wafer resection). In the case of ongoing pain, ulnar shortening sufficiently alleviates ulnar-sided wrist pain. Thereby, modern standardized operation techniques are safe enough to ensure bone healing at the osteotomy site. The aim of alleviating ulnar-sided wrist pain is mostly achieved if the correct treatment option is chosen.

Treatment of Ulnar Impaction Syndrome with and without Central TFC Lesion

Background  Arthroscopic debridement of the triangular fibrocartilage (TFC) is well accepted in patients with ulnar impaction syndrome with central TFC lesions. Treatment remains controversial, however, when there is no such lesion from radiocarpal view. Purpose  This study assessed the clinical outcome of arthroscopic central TFC resection and debridement and secondary ulnar shortening in patients with ulnar impaction with central TFC lesion compared with patients without TFC lesion. Patients and Methods  Thirty-two consecutive patients with ulnar impaction syndrome were arthroscopically treated, 16 of whom had a central lesion of the TFC that was debrided. In the 16 patients with no lesion from the radiocarpal view, the TFC was centrally resected and debrided to decompress the ulnocarpal joint. Persisting symptoms necessitated ulnar shortening in four patients in each group. Two patients underwent repeat arthroscopic TFC debridement. All patients were examined at 3, 6, and 12 months, and at final follow-up (mean: 1.7 years) following arthroscopy, respectively ulnar shortening or hardware removal. Results  In both groups, pain, Krimmer, and DASH scores significantly improved. Improvements of DASH scores were significantly higher in patients without lesion at 12 months and at final follow-up. For other parameters, no significant difference was found between the two groups. Conclusion  In both situations, with and without central TFC lesion, resection and debridement sufficiently reduced the ulnar-sided wrist pain and improved function in three out of four patients, and therefore qualified as the first-line treatment of ulnar impaction syndrome as arthroscopy is performed, anyway. Those patients who complained of persisting or recurrent ulnar-sided wrist pain finally benefitted from ulnar shortening osteotomy as the secondary procedure. Level of Evidence  Therapeutic III, case-control study.

High-resolution MRI (3T-MRI) in diagnosis of wrist pain: is diagnostic arthroscopy still necessary?

INTRODUCTION

3T MRI has become increasingly available for better imaging of interosseous ligaments, TFCC, and avascular necrosis compared with 1.5T MRI. This study assesses the sensitivity and specificity of 3T MRI compared with arthroscopy as the gold standard.

PATIENTS AND METHODS

Eighteen patients were examined with 3T MRI using coronal T1-TSE; PD-FS; and coronal, sagittal, and axial contrast-enhanced T1-FFE-FS sequences. Two musculoskeletal radiologists evaluated the images independently. Patients underwent diagnostic arthroscopy.

RESULTS

The classifications of the cartilage lesions showed good correlations with the arthroscopy findings (κ = 0.8-0.9). In contrast to the arthroscopy, cartilage of the distal carpal row was very good and could be evaluated in all patients on MRI. The sensitivity for the TFCC lesion was 83%, and the specificity was 42% (radiologist 1) and 63% (radiologist 2). For the ligament lesions, the sensitivity and specificity were 75 and 100%, respectively, with a high interobserver agreement (κ = 0.8-0.9).

DISCUSSION

3T MRI proved to be of good value in diagnosing cartilage lesions, especially in the distal carpal row, whereas wrist arthroscopy provided therapeutic options. When evaluating the surgical therapeutical options, 3T MRI is a good diagnostic tool for pre-operatively evaluating the cartilage of the distal carpal row.

Preventable Repeat Wrist Arthroscopies: Analysis of the Indications for 133 Cases

Background Frequently, patients undergo repeated wrist arthroscopies for single wrist problems. Purpose The purposes of this study were to assess the indications for repeat wrist arthroscopies and to identify potentially preventable procedures. Methods For this retrospective, two-center study, the electronic patient records were examined for patients, who underwent repeat wrist arthroscopy in a 5-year period. The cases were sorted by the underlying pathologies and the causes that necessitated repeat arthroscopies. Results Ulnar-sided wrist pain accounted for 100 (77%) of all 133 revision arthroscopies: 67 of which due to suspected ulnar triangular fibrocartilage complex (TFCC) avulsions, 33 due to ulnar impaction syndromes. Cartilage was reassessed in 22 (17%) wrists. Thereby, insufficient preoperative diagnostics necessitated pure diagnostic before therapeutic arthroscopy in 49 (37%) wrists: 48 of which for TFCC pathologies, one for a scapholunate (SL) ligament lesion. The uncertainty of diagnosis despite previous arthroscopy necessitated 18 (14%) revision arthroscopies: 15 for ulnar TFCC avulsions, 1 for a central TFCC lesion, 2 to reevaluate the SL ligament. Inadequate photo or video documentation of the cartilage necessitated arthroscopic reassessment in 16 (12%) wrists. Conclusion In this series, two out of three revision arthroscopies could potentially have been prevented. Inadequate preoperative diagnostics with the lack of reliable preoperative diagnoses necessitated pure diagnostic arthroscopies for ulnar-sided wrist pain. However, even arthroscopically, the diagnosis of ulnar TFCC avulsions or SL ligament lesions is not trivial. Surgical skills and experience are necessary to detect such lesions. Finally, adequate photo or video documentation may prevent repeated arthroscopic diagnostic procedures. Level of Evidence Level IV.

Clinical tests and magnetic resonance imaging have limited diagnostic value for triangular fibrocartilaginous complex lesions

INTRODUCTION

The diagnostic value of clinical tests and magnetic resonance (MR) imaging for the investigation of triangular fibrocartilaginous complex (TFCC) lesions is not clear due to a lack of clinical data.

MATERIALS AND METHODS

We retrospectively analyzed 908 patients who underwent clinical tests and arthroscopy for suspected TFCC lesions at our institution. Further, MR imaging findings concerning the TFCC were gathered. We correlated clinical tests and MR imaging findings with those obtained during arthroscopy, and we calculated sensitivity, specificity, as well as positive and negative predictive values.

RESULTS

In the whole cohort, the positive predictive values of all clinical tests were low, ranging from 0.53 to 0.55. The ulna grinding test had the highest sensitivity, but lowest specificity. Sensitivity and specificity of the ulnar fovea sign and magnetic resonance imaging were similar, ranging from 0.73 to 0.76, and from 0.41 to 0.44, respectively. To some degree, the diagnostic value seemed to depend on the Palmer class of TFCC lesion.

CONCLUSIONS

According to this study, clinical tests and MR imaging findings are of very limited diagnostic value for the diagnosis of TFCC lesions.

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

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

Anatomical transosseous fixation of the deep and superficial fibers of the radioulnar ligaments

INTRODUCTION

The triangular fibrocartilage complex is in conjunction with the interosseous membrane the most important stabilizer of the distal radioulnar joint. Lesions of the triangular fibrocartilage complex may cause instability of the distal radioulnar joint with serious consequences. Therefore, the goal is to reconstruct and provide stability to prevent further harm.

SURGICAL TECHNIQUE

Based on the anatomical configuration of the radioulnar ligaments, we present a technique which addresses both the deep and the superficial fibers of the radioulnar ligaments. This surgical procedure can be performed either openly or arthroscopically assisted. Two osseous 2-mm tunnels starting from the ulnar neck to the foveal surface are created. A nonabsorbable suture is passed through the tunnels and the triangular fibrocartilage using a 20-gauge venipuncture needle in order to attach the deep fibers. Then a third osseous tunnel starting from the lateral base of the styloid process to the medial aspect is created. The suture is passed through this tunnel and through the triangular fibrocartilage and around the styloid process palmarily using the same needle as before in order to anchor the superficial fibers anatomically. After reducing the ulna head the sutures are tightened.

CONCLUSION

This technique is quite simple and addresses the anatomical configuration of the radioulnar ligaments.

Distal radio-ulnar joint instability in children and adolescents after wrist trauma

This study retrospectively evaluated the medical records and radiographs of patients younger than aged 25 that were referred for a second opinion due to ulnar-sided wrist pain and persistent distal radio-ulnar (DRU) joint instability. We identified 85 patients with a major wrist trauma before the age of 18. Median age at trauma was 14 years. Median time between trauma and diagnosis of DRUJ instability was 3 years. Sixty-seven patients (79%) had sustained a fracture at the initial trauma. The two most common skeletal injuries related to the DRUJ instability were Salter-Harris type II fractures (24%) and distal radius fractures (19%). In 19 patients (22%), the secondary DRUJ instability was caused by malunion or growth arrest. Eighteen patients (21%) had no fracture; in spite of this, they presented with subsequent symptomatic DRUJ instability. Fourteen of these 18 patients had a triangular fibrocartilage complex (TFCC) tear, confirmed by arthroscopy, open surgery, or magnetic resonance imaging. In conclusion, late DRUJ instability due to wrist fractures or isolated TFCC tears was found to be common in children and adolescents.

LEVEL OF EVIDENCE

IV.