Carpal ligamentous disruptions and negative ulnar variance

Negative ulnar variance is a condition in which the ulna is relatively shorter than the radius at the carpus. It was found in 21% of 203 normal wrists. We have observed an increased incidence (49%) of this anomaly in patients with carpal ligamentous instabilities (dorsiflexion instability, palmar flexion instability, scapholunate dissociation with rotary luxation of the scaphoid, and lunate and perilunate dislocations). While the reasons for this association have yet to be adequately delineated, the presence of a negative ulnar variant may serve as an impartial clue to the presence of ligamentous instability. Many carpal instabilities present with subtle radiographic findings requiring careful evaluation of radiographs. Patients with negative ulnar variance and histories suggestive of ligamentous instability should undergo careful radiologic evaluation to assure early diagnosis of carpal disruption.     

MR imaging of normal extrinsic wrist ligaments using thin slices with clinical and surgical correlation

Eighty-nine MR examinations of the wrist were retrospectively analyzed. MRI results were compared with clinical findings and/or arthroscopy. Thin proton density and T2 weighted sequences and 3D DESS weighted sequences were applied on a 1.5 T scanner. On the palmar side three radiocarpal ligaments are recognized including the radioscaphocapitate, radiolunotriquetral, radioscapholunate, and midcarpal triquetroscaphoidal ligaments. Ulnocarpal ligaments include the ulnolunate ligament and the ulnotriquetral ligament. On the dorsal side three ligaments are recognized: the dorsal radiolunotriquetral, and the midcarpal triquetroscaphoidal and triquetro-trapezoido-trapezial. The collateral ligaments include the radial and ulnar collateral ligament. MR is a valuable technique in the assessment of the extrinsic and midcarpal ligaments. Depiction of the extrinsic ligaments can best be accomplished with coronal 3D DESS sequences and sagittal and transverse proton density and T2 weighted sequences with thin slices.     

Ultrasonographic evaluation of normal extrinsic and intrinsic carpal ligaments: preliminary experience

Objective To determine normal anatomy of extrinsic and intrinsic carpal ligaments at ultrasonography (US).Design and volunteers In the first part of the study, two musculoskeletal radiologists retrospectively reviewed in consensus the photographs of anatomic sections and dissections derived from 20 cadaveric wrists. This cadaveric study gave the two readers the opportunity to learn the anatomy and orientation of the various extrinsic and intrinsic carpal ligaments and, thus, to develop a US protocol to facilitate the recognition of each carpal ligament. In the second part of the study, these two radiologists prospectively and independently evaluated the visibility of extrinsic and intrinsic carpal ligaments in 30 wrists of volunteers, using the same US protocol.Results With regard to extrinsic carpal ligaments, the radioscaphocapitate ligament (partially visible, 38%; completely visible, 62%), the radiolunotriquetral ligament (partially visible, 27%; completely visible, 73%), the palmar ulnotriquetral ligament (partially visible, 12%; completely visible, 88%), and the dorsal radiotriquetral ligament (partially visible, 7%; completely visible, 93%) were visualized at US. The dorsal ulnotriquetral ligament (partially visible, 21%; completely visible, 74%), the ulnolunate ligament (partially visible, 5%; completely visible, 70%), and the radial collateral ligament (partially visible, 18%; completely visible, 12%) were more difficult to recognize. The radioscapholunate ligament was never seen. With regard to intrinsic carpal ligaments, the dorsal (partially visible, 11%; completely visible, 89%) and palmar (partially visible, 38%; completely visible, 62%) scaphotriquetral ligaments as well as the dorsal scapholunate ligament (partially visible, 3%; completely visible, 97%) were visualized at US. The dorsal lunotriquetral ligament (partially visible, 39%; completely visible, 61%) and the palmar scapholunate ligaments (partially visible, 12%; completely visible, 81%) were more difficult to recognize.Conclusion US may be helpful in identifying the major extrinsic and intrinsic carpal ligaments.     

Ultrasound and magnetic resonance angiography features of post-traumatic ulnar artery pseudoaneurysm: a case report and review of the literature

Ulnar artery pseudoaneurysms are very uncommon. The least common etiological mechanism is a single direct trauma. It is important to identify these lesions, which may have important clinical complications such as distal thrombosis with digital ischemia or gangrene. This report describes the features of sonography and magnetic resonance angiography of a histologically confirmed ulnar artery pseudoaneurysm.     

MR imaging of ulnar impaction

The ulnar impaction syndrome of the wrist is a well-recognized clinical entity, usually showing distinct radiographic features including a positive ulnar variance and degenerative subchondral changes of the distal ulna, proximal lunate, and proximal triquetrum. Confirmation of the clinical and plain film findings with advanced imaging is often necessary to exclude other entities with a similar clinical presentation. Although arthrography and bone scintigraphy are helpful in this work-up, magnetic resonance imaging (MRI) appears to be both a sensitive and a specific means of evaluation. The imaging studies in four patients with clinically and surgically diagnosed ulnar impaction are described, with emphasis on MRI findings. MRI appears to be the modality of choice in the evaluation of patients with suspected ulnolunate impingement.     

MR imaging in chronic rupture of the ulnar collateral ligament of the thumb

Purpose: MR imaging has been shown as the best radiologic method for verifying and classifying acute ulnar collateral ligament (UCL) ruptures of the thumb. Our aim was to analyse the usefulness of MR also in old ruptures and to establish the most useful sequences.Material and Methods: Ten patients with an old UCL rupture of the thumb were preoperatively imaged using 1.5 T MR. Three radiologists blinded to the findings separately analysed the MR images of these patients and of 10 age-and sex-matched voluntary controls. MR findings of the patients were compared with those of surgery.Results: The consensus diagnosis of an UCL rupture was accurate in all 10 patients. All controls were classified as having no UCL rupture. In 5 of the 7 patients with a surgically defined Stener or non-Stener lesion, the consensus diagnosis was the same as the operative diagnosis. Due to excessive scarring it was not possible to verify any Stener lesion intra-operatively in 3 patients. The most informative MR sequence was T2 TSE in the coronal plane, the second most informative was T1 SE with fat suppression in the coronal plane.Conclusion: An old UCL rupture is well verified by MR but typing of the lesion as either a Stener or non-Stener type is not always possible.     

Hook of the hamate fracture not visualized by standard wrist or classic carpal tunnel projections

After trauma to the wrist, hook of the hamate fracture may not be visualized by standard plain film and classic carpal tunnel views. In such cases, "spot" radiographs may be helpful.     

The role of ultrasonographic measurements of the median nerve in the diagnosis of carpal tunnel syndrome

AIM: The aim of study was to assess the usefulness of ultrasonographic measurements of the median nerve in the diagnosis of carpal tunnel syndrome. MATERIALS AND METHODS: Eighty-six patients with carpal tunnel syndrome confirmed by electromyography and 45 asymptomatic controls were included in the study and underwent high-resolution ultrasonography of the wrists. The cross-sectional area and flattening ratio at the level of the pisiform bone of the proximal carpal tunnel were measured. Data from the patient group and control group were compared to determine the statistical significance. The accuracy of the ultrasonographic diagnostic criteria for carpal tunnel syndrome was evaluated using receiver-operating characteristic (ROC) analysis. RESULTS: One hundred and forty-eight wrists of 86 patients with carpal tunnel syndrome and 76 wrists of 45 control patients were examined. All measurements showed significant differences between patients and controls. Increased cross-sectional area of the median nerve was the most predictive measurement of carpal tunnel syndrome. Using the ROC curve, a cut-off value of >10.5 mm2 at the level of pisiform bone provided a diagnostic sensitivity of 89% and specificity of 94.7% CONCLUSION: The ultrasonographic measurement of the median nerve cross-sectional area is a sensitive, specific and useful non-invasive method for the diagnosis of carpal tunnel syndrome.     

Rotatory subluxation of the scaphoid

Rotatory subluxation of the scaphoid is an uncommon abnormality which is not widely understood. It can be difficult to diagnose and, if incorrectly managed, can lead to a severe and disabling radio-carpal arthritis. While complicating many forms of wrist trauma, its place in the lunate-perilunate dislocation spectrum being especially important, the abnormality may occur in the absence of trauma, such as with rheumatoid arthritis; its association with Kienb?ck's disease is documented in this paper. The mechanisms underlying the subluxation are discussed and the importance of early diagnosis is stressed. Eight cases of rotatory subluxation of the scaphoid are reported to illustrate the presentations, symptomatology and complexities of diagnosis.     

Dynamic MR imaging of carpal tunnel syndrome

 Objective. To evaluate the diagnostic value of the MR imaging syndrome before and after performance of provocative exercises in patients with dynamic carpal tunnel syndrome. Design. Fat-suppressed proton-density and T2-weighted spin-echo images of the wrist were obtained prior to and after provocative, standardized exercises. Images were interpreted in masked fashion with regard to six MR criteria of carpal tunnel syndrome: (a) bowing of the transverse ligament, (b) and (c) deformation of the median nerve at the pisiform and hamate levels respectively, (d) signal abnormality of the median nerve, (e) presence of fluid in the wrist joints and/or carpal tunnel, and (f) presence of synovial swelling. Patients. Twenty-one wrists in 20 patients with subjective complaints of carpal tunnel syndrome and equivocal or negative clinical findings and negative electrodiagnostic examinations were included (age range 21–61 years, mean 37 years, 2 men and 18 women). The diagnosis of dynamic carpal tunnel syndrome was made and confirmed by surgery in 18 of the 21 symptomatic wrists. The control group consisted of 15 asymptomatic wrists in volunteers (age range 22–60 years, mean 35 years, 8 men and 7 women). Results and conclusions. Sensitivities and specificities of the six MR criteria were 90.5–100%, and 6.7–86.7%, respectively, both before and after exercise. Likelihood ratios proved statistically significant differences between the symptomatic and asymptomatic wrists (P<0.0001–0.0002) for the prevalence of all MR criteria with the exception of fluid within the carpal joints and/or carpal tunnel. Changes of the MR appearance after exercise had a low sensitivity (4.8–71.4%) but high specificity (86.7–100%) for dynamic carpal tunnel syndrome. In conclusion, MR imaging contributes to the diagnosis of carpal tunnel syndrome when clinical signs are confusing and electrodiagnostic studies are negative. Dynamic examinations improve specificity of MR imaging for such diagnosis.     

Ultrasonographic assessment of mild and moderate idiopathic carpal tunnel syndrome

AIM: To investigate the diagnostic value of ultrasonography in mild and moderate idiopathic carpal tunnel syndrome (CTS). MATERIALS AND METHODS: Cross-sectional areas (CSA), flattening ratios at three different levels, swelling ratio, and palmar displacement were analysed in 26 patients (14 with bilateral and 12 with unilateral disease, 40 wrists in total) for the presence and the severity of CTS. Twenty had normal nerve conduction studies (NCS) defined as "mild", and 20 of them had abnormal NCS defined as "moderate". The control group consisted of 20 healthy participants. RESULTS: All parameters were significantly different between patient and control groups. Palmar displacement, swelling ratio, CSA at all levels and distal flattening ratio had the highest significance (p < 0.0001). The criterion with the highest sensitivity was the swelling ratio > or = 1.3 (72.5%), followed by the middle CSA > 9 mm2 and the palmar displacement > 2.5 mm. All of these criteria had a higher sensitivity in diagnosing moderate cases (85-100%) than diagnosing mild cases (30-55%). There was a significant difference between normal and mild CTS groups regarding palmar displacement, distal flattening ratio, middle CSA and swelling ratio (p < 0.0001 for all) and between normal and moderate groups regarding all parameters (p < 0.01 - 0.0001) When combined middle CSA, palmar displacement and swelling ratio had an overall discriminatory accuracy of 83.8%. CONCLUSION: Additional diagnostic confirmation can be provided by ultrasonography and may be preferred as the initial step instead of electrophysiological studies. Detection of at least two of the three criteria (median nerve CSA > 9 mm2 at pisiform level, swelling ratio > or = 1.3, and palmar displacement > 2.5 mm) may be helpful for the verification of the diagnosis.     

Stress reaction in the carpal bones caused by breakdancing

Stress reactions in the bones of the lower extremities are a common finding on magnetic resonance (MR) imaging. The primary finding in the bone marrow is nonspecific edema without any visible fracture line that may even mimic tumor or infection. Continuing stress may eventually lead to a stress fracture. We present the case of a stress reaction related to breakdancing in a less typical localization, in the triquetral bone in the wrist.     

Dislocation of the second through fifth carpometacarpal joints

We report a case of dislocation of the second through fifth carpometacarpal joints and review the mechanism of injury and radiographic findings in such injuries.     

High-resolution computed tomography of the wrist in patients with carpal tunnel syndrome

High resolution computed tomography (CT) was used to scan the wrists of 19 patients with idiopathic carpal tunnel syndrome. Thirteen normal volunteers were used as controls. Measurements obtained from the CT images included the cross-sectional area of the carpal tunnel, the relative amount of synovium within the carpal tunnel, the attenuation coefficient of the carpal tunnel, and the thickness of the transverse carpal ligament. No significant difference in any of these measurements was found when comparing the wrists of symptomatic patients with controls. High resolution CT of the wrist does not appear to be of value in the preoperative evaluation of patients with idiopathic carpal tunnel syndrome.     

A comparison of the performance of anatomical MRI and DTI in diagnosing carpal tunnel syndrome

Purpose

To compare the performance of anatomical magnetic resonance imaging (MRI) with that of diffusion tensor imaging (DTI) in the diagnosis of carpal tunnel syndrome (CTS).

Materials and methods

We performed 3T anatomical MRI and DTI on 42 patients and 42 age-matched controls. The median nerve cross-sectional area (CSA), relative median nerve signal intensity, and palmar bowing of the flexor retinaculum, assessed with anatomical MRI, and fractional anisotropy (FA) and apparent diffusion coefficient of the median nerve, assessed with DTI, were measured at four locations: the hamate level, the pisiform level (P0), the level located 1 cm proximal to the P0 level (P1), and the distal radioulnar joint level (DR). Adding the ratios and differences of the median nerve parameters between the measurements at the DR and other locations to the diagnostic parameters, we evaluated the area under the receiver operating characteristic curves (AUCs) of all the diagnostic parameters of both scans.

Results

The AUCs of FA(P1) (0.814) and FA(P0) (0.824) in DTI were larger than the largest AUC for anatomical MRI, CSA(P1) (0.759). However, the receiver operating characteristics of the three parameters were not significantly different (P > 0.1). The sensitivity and specificity of CSA(P1) (76.2% and 73.8%) and FA(P1) (73.8% and 76.2%) increased after inclusive and exclusive combination to 90.5% each.

Conclusion

The individual performances of both scans were not significantly different in diagnosing CTS. Measuring both CSA and FA at P1 may be useful and efficient to utilize the merits of both scans and to increase the CTS diagnostic performance.     

桡骨远端关节内骨折伴腕关节不稳定放射诊断

目的 分析继发性腕关节不稳定与桡骨远端骨折类型的关系，讨论腕关节不稳定发生机制和防治措施。方法 对67例共75个腕部桡骨远端关节内骨折随访2a～6a，在复位前、后和去除外固定后的腕关节正侧位平片上分别测量腕高指数、尺腕距离比、舟月骨距、舟月骨角、桡月骨角、头月骨角，并测定腕关节功能的主、客观指标。比较合并与不合并腕关节不稳定两组的功能恢复情况。结果 伴有腕关节不稳定的发生率为58．67％（44／75），其中，腕背侧镶嵌不稳定（DISI）29例（38．67％），舟月骨分离9例（12．00％），其他为掌侧镶嵌不稳定、尺侧偏移和头月骨间不稳定等，多发生在严重骨折移位患者。骨折愈合后，合并腕关节不稳定的功能明显差于单纯桡骨远端骨折患者。结论 桡骨远端骨折类型、关节面弧度和掌倾角对腕关节不稳定的发生及类型有显著影响。对骨折移位严重或高能量损伤的桡骨远端骨折，要注意是否合并腕关节不稳定。对合并腕关节不稳定的桡骨远端骨折．复位时应尽可能恢复掌倾角.     

Ulnar variance in children — standard measurements for evaluation of ulnar shortening in juvenile rheumatoid arthritis,hereditary multiple exostosis and other bone or joint disorders in childhood

Measurements for radioulnar variance in adults cannot be used in children because the epiphyses are not fully ossified. We describe a method of determining ulnar variance in children by using the distance from the distal metaphysis of the radius to the distal metaphysis of the ulna. Standards for this measurement are presented for ages 1.5 to 15.5 years in boys and girls. These measurements change little with age and may be helpful in establishing shortening of the ulna which may be seen in juvenile rheumatoid arthritis, hereditary multiple exostosis, or other bone and joint diseases with childhood onset.     

Radial and ulnar bursae of the wrist: cadaveric investigation of regional anatomy with ultrasonographic-guided tenography and MR imaging

Objective To demonstrate the anatomy of the radial and ulnar bursae of the wrist using MR and US images.Design Ultrasonographic-guided tenography of the tendon sheath of flexor pollicis longus (FPL) and the common tendon sheath of the flexor digitorum of the fifth digit (FD5) of ten cadaveric hands was performed, followed by magnetic resonance imaging and gross anatomic correlation. Patterns of communication were observed between these tendon sheaths and the radial and ulnar bursae of the wrist.Results The tendon sheath of the FPL communicated with the radial bursa in 100% (10/10) of cases, and the tendon sheath of the FD5 communicated with the ulnar bursa in 80% (8/10). Communication of the radial and ulnar bursae was evident in 100% (10/10), and presented an “hourglass” configuration in the longitudinal plane.Conclusions The ulnar and radial bursae often communicate. The radial bursa communicates with the FPL tendon sheath, and the ulnar bursa may communicate with the FD5 tendon sheath.