Evaluation of the triangular fibrocartilage and the scapholunate and lunotriquetral ligaments in cadavers with low-field-strength extremity-only magnet. Comparison of available imaging sequences and macroscopic findings

Arthroscopic scapholunate joint reduction. Is an effective treatment for irreparable scapholunate ligament tears?

BACKGROUND

Irreparable tears to the scapholunate (SL) interosseous ligament area are common causes of mechanical wrist pain and yet treatment of this condition remains challenging. The reduction association of the SL joint (RASL) technique alleviates pain while preserving wrist function by creating a fibrous pseudarthrosis stabilized by a cannulated screw placed through the SL joint. Although arthroscopic RASL (ARASL) is a minimally invasive alternative to the open procedure, its effectiveness in controlling pain and preserving wrist function has not been established.

QUESTIONS/PURPOSES

To determinate whether ARASL was obtained relieve pain and restore function to the wrist.

PATIENTS AND METHODS

We reviewed eight patients (nine wrists) who had ARASL for SL instability with a reducible SL ligament tear (chronic lesion) from 2005 to 2009. Seven of eight were males and mean age was 44.5 years (range, 38-56 years). We recorded pain using a scale, the Disabilities of the Arm, Shoulder and Hand (DASH) score, grip strength, and range of motion (ROM). Minimum followup was 12 months (mean, 34.6 months; range, 12-43 months).

RESULTS

The visual analog pain score was rated 5.4 (range, 0-10) preoperatively and 1.5 (1-3) after ARASL. Postoperative grip strength of the wrist was 78% of the contralateral, unaffected wrist. The average postoperative wrist ROM was to 107°, 20% less than the preoperative ROM. The SL angle decreased from 70.5° to 59.3°. In three cases, screws were removed owing to loosening or symptoms.

CONCLUSIONS

Our preliminary observations suggest ARASL for treating irreparable SL ligament tear is feasible, controls pain, and improves wrist function while preserving ROM. Larger series with longer followup are required to confirm our observations.

LEVEL OF EVIDENCE

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

Diagnostic comparison of 1.5 Tesla and 3.0 Tesla preoperative MRI of the wrist in patients with ulnar-sided wrist pain

PURPOSE

The diagnostic sensitivity, specificity, and accuracy of 1.5 Tesla (T) and of 3.0T magnetic resonance imaging (MRI) are correlated with wrist arthroscopy findings in patients presenting with ulnar-sided wrist pain.

METHODS

The records and diagnostic MRI scans of 102 patients who presented between 1997 and 2006 with ulnar-sided wrist pain were evaluated. Preoperative MRI scans at 1.5T (n = 70) and 3.0T (n = 32) were evaluated by 2 experienced musculoskeletal radiologists with different levels of experience who were blinded to the arthroscopic findings. Preoperative MRI findings for the triangular fibrocartilage complex (TFCC), scapholunate, ulnotriquetral, and lunotriquetral ligaments were recorded and compared with findings at diagnostic arthroscopy. The sensitivity, specificity, and accuracy were calculated for both the 1.5T and 3.0T preoperative MRI scans. Statistical comparisons were made using chi-square test and JMP 6.0 software.

RESULTS

A tear of the TFCC was identified retrospectively on 1.5T images in 49 of 58 patients and on 3.0T images in 15 of 16 patients. Compared with the gold standard of arthroscopy, 1.5T wrist MRI in this patient population had a sensitivity of 85%, a specificity of 75%, and an accuracy of 83% for reader 1 for the detection of a tear of the TFCC. In the same patient population, 3.0T wrist MRI had a sensitivity of 94%, a specificity of 88%, and an accuracy of 91% for reader 1. For reader 2, the improvement in sensitivity for the lunotriquetral ligament between the 1.5T and 3.0T images was statistically significant.

CONCLUSIONS

The sensitivity, specificity, and accuracy of 3.0T wrist MRI for the TFCC is consistently higher compared with those of 1.5T wrist MRI. The trend suggests that 3.0T wrist MRI provides improved capability for detection of TFCC injuries. Given the available sample size, however, the confidence intervals around the point estimates are wide and overlapping. Further studies are needed to confirm or refute our results of the estimated sensitivity, specificity, and accuracy parameters.

Role of magnetic resonance imaging in musculoskeletal trauma

The unique ability of magnetic resonance (MR) imaging to visualize injuries of bone, cartilage, bone marrow, and supporting soft tissue structure makes it ideally suited for the evaluation of musculoskeletal trauma. Magnetic resonance imaging also offers exquisitely detailed anatomical information on the musculoskeletal system. The widespread availability of MR imaging and the constantly improving technology make it the imaging modality of choice for the patients with a musculoskeletal trauma. This review discusses the role and applications of MR imaging for musculoskeletal trauma. It covers traumatic conditions of the musculoskeletal system, including hemarthrosis, lipohemarthrosis, stress fracture, occult fractures, cartilage injuries, the muscle and tendon trauma, avulsion injuries, extensor mechanism injuries, and traumatic conditions of joints.

MR Imaging of Ligaments and Triangular Fibrocartilage Complex of the Wrist

Imaging of the wrist with MR imaging can be difficult because of the small size of this joint, its complex anatomy, and its sometimes poorly understood pathologic lesions. A recent study by Hobby and coworkers of 98 patients revealed that MR imaging of the wrist influences clinicians' diagnoses and management plans in most patients. This article summarizes the current diagnostic criteria that can be useful in interpreting abnormalities of the wrist ligaments and triangular fibrocartilage complex (TFCC) of the wrist in this difficult topic in joint MR imaging.

High-resolution MR imaging of the proximal zone of the lunotriquetral ligament with a microscopy coil

OBJECTIVE

To evaluate high-resolution MRI of the proximal zone of the lunotriquetral ligament (LTL) using a microscopy surface coil with a 1.5 T scanner.

DESIGN AND SUBJECTS

The proximal zone of the LTL was reviewed in 90 subjects (23 asymptomatic normal volunteers and 67 patients with suspicion of triangular fibrocartilage complex injury) with high-resolution MRI using a 47-mm microscopy surface coil. High-resolution MR images were obtained with gradient recalled echo (GRE) T2*-weighted sequence and short tau inversion recovery imaging, with a 1- to 1.5-mm slice thickness, a 50-mm field of view, an imaging matrix of 140-224x512 using zero fill interpolation, and 3-4 excitations. As a qualitative analysis, the LTL was classified in shape and signal intensity.

RESULTS

The triangle-shaped low-signal-intensity LTL was identified in 77 of 90 subjects (85.6%) on GRE images. The triangle was classified as regular (41.1%), broad-based (20.0%), narrow-based (6.7%), or asymmetrical (17.8%). The bar-shaped ligament was seen in one patient, and unclassified ligaments were seen in 12 patients. All volunteers showed triangle-shaped LTL. The MR signal intensity of the proximal zone in the LTL was characterized as homogeneously low intensity (type 1; 33.8%), linear intermediate or high signal intensity traversing the distal surface of the LTL (type 2; 45.5%), and linear intermediate or high intensity traversing both distal and proximal surfaces of LTL (type 3; 20.8%).

CONCLUSION

The proximal zone of the LTL showed a broad spectrum of normal variations in shape and signal intensity on high-resolution MR images with a microscopy coil.

Musculoskeletal Imaging at 3T: Current Techniques and Future Applications

MSK MR imaging applications are making the transition rapidly from 1.5T to 3T. Initial experience in the knee suggests that the higher SNR provides technical improvement in routine clinical imaging with the potential for greater accuracy in the diagnosis of articular cartilage injury. Similarly, initial experience with 3T MR imaging in the evaluation of the hip and small joints of the hand and wrist has been positive. In other joints, clinical development has been limited by the lack of availability of dedicated surface coils, and sensitivity of 3TMR imaging to artifact. The clinical impact of this technology remains uncertain because no published controlled clinical trial has evaluated the impact of 3T MR imaging on diagnostic outcomes. In addition to clinical application, 3T MR imaging has an important role for furthering translational research in MSK diseases through the development of new molecular and functional MR imaging techniques.

MR imaging of ligaments and triangular fibrocartilage complex of the wrist

Imaging of the wrist with MR imaging can be difficult because of the small size of this joint, its complex anatomy, and its sometimes poorly understood pathologic lesions. A recent study by Hobby and coworkers of 98 patients revealed that MR imaging of the wrist influences clinicians' diagnoses and management plans in most patients. This article summarizes the current diagnostic criteria that can be useful in interpreting abnormalities of the wrist ligaments and triangular fibrocartilage complex (TFCC) of the wrist in this difficult topic in joint MR imaging.