Wrist injuries in young adults: The diagnostic impact of CT and MRI

Purpose

To evaluate the diagnostic impact of MRI or/and multidetector CT in young patients with wrist injury and inconclusive or negative clinical examination and X-rays and to analyze variations in imaging strategies between a district general hospital (GH) and a university hospital (UH).

Materials and methods

A retrospective analysis of 34 young patients (mean age 23 years) with wrist trauma who underwent CT or/and MRI was performed. The injury was acute in 24, and chronic in 10 patients. Twenty-two patients were from a GH and 12 from a UH. Two experienced musculoskeletal radiologists blindly reviewed the imaging studies. The effect of cross-sectional imaging on patient care and treatment plan was evaluated.

Results

In 9 of 34 patients one or more fractures were diagnosed on cross-sectional imaging. The scaphoid was fractured in four patients, the lunate and/or the trapezium in three patients, the scaphoid together with the lunate in one patient, and finally the distal radius in one patient. Ligamentous trauma was identified solely on MRI in 11 patients (involving the TFCC in eight cases). In four patients with both imaging methods, CT revealed one fracture of the trapezium not seen on MRI, and one scapholunate fracture with MRI findings of distal radial fracture only. In two patients with normal CT, MRI revealed bone marrow oedema of the scaphoid in one and of the distal radius, lunate and triquetrum in the other.

Conclusion

Both CT and MRI might be considered in patients with acute or chronic wrist injury, clinical dilemma and normal initial radiographs, depending on the availability and the individual institution policies.     

Lunate chondromalacia: evaluation of routine MRI sequences

OBJECTIVE: Chondromalacia is a commonly encountered abnormality at arthroscopy and may be responsible for significant clinical symptoms and disability. In the wrist, the most common location for chondromalacia is the lunate bone. Consequently, we sought to study the accuracy of clinical MRI in the assessment of lunate articular cartilage. MATERIALS AND METHODS: MR images of 34 patients who underwent arthroscopy and had an MRI examination within 1 month of surgery were evaluated by two reviewers for the presence and location of lunate cartilage defects and subchondral edema. RESULTS: Lunate cartilage defects were seen on MRI in 10 of the 13 patients with chondromalacia, but these defects were also incorrectly noted in three of 21 of patients without chondromalacia. The visible locations for cartilage defects were the ulnar aspect of the proximal lunate bone (n = 3), radial aspect of the proximal lunate bone (n = 4), ulnar aspect of the distal lunate bone (n = 2), and radial aspect of the distal lunate bone (n = 1). Subchondral marrow edema was observed in six of the 10 patients with chondromalacia seen on MRI; in all six patients, the edema was seen in the same quadrant as the cartilage defect. Marrow edema was detected in one patient without chondromalacia. CONCLUSION: We conclude that lunate chondromalacia can be accurately assessed using routine MRI sequences, although there are occasional false-positive interpretations.     

CT arthrography of the wrist using a novel, mobile, dedicated extremity cone-beam CT (CBCT)

Purpose

To evaluate the feasibility and intra- and interobserver agreement of CBCT arthrography of wrist ligaments, triangular fibrocartilaginous complex (TFCC), and to assess the sensitivity (SE), specificity (SP), accuracy (ACC), and positive and negative predictive value (PPV, NPV) of CBCT arthrography in the diagnosis of scapholunate (SLL) and lunotriquetral (LTL) ligament tears, TFCC, and cartilage abnormalities of the scaphoid and lunate with their corresponding radial surfaces (scaphoid and lunate fossa) using a novel, mobile, dedicated extremity CBCT scanner.

Materials and methods

Fifty-two consecutively enrolled subjects (26 M, 26 F, mean age 38 years, range 18–66 years) with suspected wrist ligament tears underwent CBCT-arthrography before normally scheduled MR arthrography.An extremity CBCT was used for imaging with isotropic voxel size of 0.4 × 0.4 × 0.4 mm³. Subsequent routine 1.5 T MRI was performed using a dedicated wrist coil.Two observers reviewed the anonymized CBCT images twice for contrast enhancement (CE) and technical details (TD), for tears of the SLL, LTL, and TFCC. Also, cartilage abnormalities of the scaphoid and lunate with their corresponding radial surfaces (scaphoid and lunate fossa) were evaluated. Inter- and intraobserver agreement was determined using weighted kappa statistics. Since no surgery was performed, MRI served as a reference standard, and SE and SP, ACC, PPV, and NPV were calculated.

Results

Intra- and interobserver kappa values for both readers (reader 1/reader 2; first reading/second reading) with 95 % confidence limits were: CE 0.54 (0.08–1.00)/ 0.75 (0.46–1.00); 0.73 (0.29–1.00)/ 0.45 (0.07–0.83), TD 0.53 (0.30–0.88)/ 0.86 (0.60–1.00); 0.56 (0.22–0.91)/ 0.67 (0.37–0.98), SLL 0.59 (0.25–0.93)/ 0.66 (0.42–0.91); 0.31 (0.06–0.56)/ 0.49 (0.26–0.73), LTL 0.83 (0.66–1.00)/ 0.68 (0.46–0.91); 0.90 (0.79–1.00)/ 0.48 (0.22–0.74); TFCC (0.72–1.00)/ (0.79–1.00); 0.65 (0.43–0.87)/ 0.59 (0.35–0.83), radius (scaphoid fossa) 0.45 (0.12–0.77)/ 0.64 (0.31–0.96); 0.58 (0.19–0.96)/ 0.38 (0.09–0.66), scaphoid 0.43 (0.12–0.74)/ 0.76 (0.55–0.96); 0.37 (0.00–0.75)/ 0.32 (0.04–0.59), radius (lunate fossa) 0.68 (0.36–1.00)/ 0.42 (0.00–0.86); 0.62 (0.29–0.96)/ 0.51 (0.12–0.91), and lunate 0.53 (0.16–0.90)/ 0.68 (0.44–0.91); 0.59 (0.29–0.88)/ 0.42 (0.00–0.84), respectively. The overall mean accuracy was 82–92 % and specificity was 81–94 %. Sensitivity for LTL and TFCC tears was 76–83, but for SLL tears it was 58 %. For cartilage abnormalities, the accuracy and negative predictive value were high, 90–98 %.

Conclusions

A dedicated CBCT extremity scanner is a new method for evaluating the wrist ligaments and radiocarpal cartilage. The method has an overall accuracy of 82–86 % and specificity 81–91 %. For cartilage abnormalities, the accuracy and negative predictive value were high.     

Magnetic resonance imaging of the wrist in early rheumatoid arthritis: a pictorial essay

This pictorial essay describes the changes seen in the wrist in early rheumatoid arthritis (RA) on MRI. Magnetic resonance imaging can demonstrate bone erosions, bone marrow signal changes, synovitis and tenosynovitis in early rheumatoid arthritis. Magnetic resonance imaging of the wrist can identify erosions in RA earlier than plain radiographs and can detect more erosions. Common sites include the capitate, lunate and scaphoid. Bone marrow signal changes occur frequently and are most common in the capitate, lunate and triquetrum. Synovial thickening and enhancement are clearly demonstrated with MRI and are most commonly seen in the radiocarpal joint (RCJ). Tenosynovitis can be seen in the wrist in more than half of patients presenting with RA. This most commonly involves the extensor carpi ulnaris tendon and is seen as sheath fluid, thickening and enhancement.     

Multiple occult wrist bone injuries and joint effusions: prevalence and distribution on MRI

This study aims (1) to assess the prevalence and distribution of multiple occult injuries of the carpal bones and the distal forearm in patients with wrist pain and negative radiographs following trauma and (2) to evaluate the distribution and significance of joint effusions in the wrists with multiple osseous injuries. One hundred and thirty-one subjects, 74 men and 57 women, were consecutively examined in two institutions. All were acute trauma patients with negative X-rays whose clinical examination suggested possible fracture at the wrist or the distal forearm. Magnetic resonance (MR) wrist imaging was performed with and without fat saturation sequences. The MR images were analysed for detection of occult trabecular contusions and cortical discontinuity in the carpus, the distal forearm and the metacarpal bases. The prevalence and distribution of the injuries were assessed along with the distribution of joint effusions. Eight patients were excluded due to inadequate image quality. Two patients had bilateral injury. A total of 125 wrists were analysed. Seventy-eight (62.4%) wrists had occult bone injuries. Among these 78, 53 (68%) wrists had more than one injured bone. Twenty-five wrists (32%) had one injured bone. The highest number of injured bones per wrist was six. Injuries with a visible fracture line were seen in 29 (37.1%) wrists on MRI. The distal radius was the most frequent location for occult fracture line (11 cases). The injuries without a fracture line (contusion) were present in 49 (63%) wrists; they were detected more frequently in the scaphoid (35 cases). The lunate (29 cases) and the triquetrum (26 cases) were almost equally affected. The bone that was less frequently injured was the pisiform (four cases). Joint effusions were present in all 53 wrists with multiple bone lesions but more often situated in the ulnocarpal space [27 (50.3%) wrists]. There was no correlation between effusions in multiple locations (grades III and IV) and multiple bone injuries. This study revealed the presence of multifocal trabecular contusions without correlation with increased joint effusions in patients with negative radiographs and persistent pain. The clinical significance of these findings deserves further investigation.     

Obturator externus bursa: prevalence of communication with the hip joint and associated intra-articular findings in 200 consecutive hip MR arthrograms

The purpose of the study was to demonstrate the prevalence of communication between the hip joint and the obturator externus bursa on hip MR arthrography. Following institutional review board approval, 200 hip MR arthrograms in 196 subjects were independently reviewed by two musculoskeletal radiologists. Discrepancies were resolved by adjudication. The presence or absence of communication between the hip joint and the obturator externus bursa was recorded. Associated lesions involving the acetabular labrum and articular cartilage were recorded. The obturator externus bursa was shown to communicate with the hip joint in 11 of the 200 (5.5%) hip MR arthrograms. Of these, six were in men and five were in women. The age range was 15–63 years with a mean age of 34 years. All 11 patients had labral tears. Eight of the 11 had cartilage lesions. The obturator externus bursa can be seen to communicate with the hip joint in 5.5% of hip MR arthrograms. Associated labral and cartilage lesions are common.     

Value of bone scintigraphy in patients with carpal trauma

OBJECTIVE: We planned this study to evaluate the role of bone scintigraphy in patients with suspected carpal fracture and normal or suspicious radiographs following carpal injury. METHODS: Three-phase bone scintigraphy using Tc-99m-MDP was performed on 32 patients with negative radiographs but clinically suspected fracture at two weeks after the trauma. Focally increased radiopharmaceutical uptake was interpreted as a fracture. The final diagnosis was established with clinical follow-up. RESULTS: Twelve (38%) patients had a normal scan excluding fracture. Twelve patients had a single fracture. Multifocal fracture was present in 8 (25%) patients. Eight patients showed scaphoid fractures; of these three showed single scaphoid fracture, and the other five patients revealed accompanying fractures. Distal radius fractures and carpal bone fractures other than scaphoid were both observed in 12 patients. These were eleven fractures of distal radius; three fractures of pisiform; two fractures of hamate; and single fractures of lunate, trapezium and triquetrum. In one patient there was fracture of a first metacarpal bone. CONCLUSION: In patients with suspected carpal bone fracture and normal or suspicious radiographs, bone scintigraphy can be used as a reliable method to confirm or exclude the presence of a scaphoid fracture and to detect clinically unsuspected fractures of distal radius and other carpal bones.     

Scaphoid and pronator fat stripes are unreliable soft tissue signs in the detection of radiographically occult fractures

AIM: To determine the clinical value of scaphoid and pronator fat stripes in identifying occult underlying scaphoid and distal radius fractures, respectively. MATERIALS AND METHODS: In our department, all patients with clinically suspected scaphoid fractures and normal scaphoid series of radiographs undergo magnetic resonance imaging (MRI) of the wrist. We selected 50 cases with unequivocal MRI evidence of scaphoid fracture, 50 cases with distal radius fracture and 50 cases with no MRI evidence of bony injury. All 150 initial plain radiographs were examined retrospectively in random order without knowledge of the MRI findings and the scaphoid and pronator fat stripes scrutinized. RESULTS: The scaphoid fat stripe was abnormal in only 25 cases (50%) with confirmed scaphoid fracture on MRI. The pronator fat stripe was abnormal in 13 cases (26%) with confirmed distal radius fracture. In the 50 cases with no MRI evidence of bony injury, the scaphoid fat stripe and pronator fat stripe were abnormal in 25 (50%) and 15 (30%) cases, respectively. The sensitivity and specificity for an abnormal scaphoid fat stripe was 50%. The sensitivity and specificity for an abnormal pronator fat stripe was 26 and 70%, respectively. CONCLUSION: Scaphoid and pronator fat stripes are poor predictors of the presence or absence of underlying occult fractures.     

Kashin-Beck disease in children: radiographic findings in the wrist

OBJECTIVE: To characterize the features and prevalence of radiographic abnormalities of the wrist in children with Kashin-Beck disease (KBD) and to determine whether the presence of radiographic abnormalities in the wrist correlates with the severity of KBD. DESIGN AND PATIENTS: Two hundred and eight posteroanterior radiographs of the right hand (including wrist) in children with KBD, ranging in age from 4 to 11 years (mean age 7.7 years), from endemic areas of China were reviewed. Carpal bony margins were evaluated for blurring, thinning, irregularity with and without sclerosis, interruption, depression or destruction. The radiocarpal, intercarpal and carpometacarpal joints were assessed for widening or narrowing. The severity of the disease was graded using the hand criteria from the Chinese Radiographic Criteria of KBD Diagnosis, which classifies the following five types according to the location of the hand involved: I, metaphysis; II, diaphysis; III, I+II; IV, metaphysis and epiphysis; V, II+IV. RESULTS: Of the 208 children, 95 had abnormalities in the hand but not in the wrist; 108 had both hand and wrist abnormalities; only five had abnormal wrist findings without any hand abnormalities. Of the 108 cases with wrist abnormalities, all the carpal bones were involved in 33 cases, of which the hand types were either IV or V. However, any individual carpal bone, or combination of bones, may become involved. The carpal bones most likely to show abnormalities were the capitate and the hamate (93%), followed by the triquetrum (31%), the lunate (9%), the scaphoid (6%), and the trapezoid and the trapezium (5%). The pisiform bones were not evaluated because they cannot be seen on the overlapping posteroanterior radiographs. The most commonly involved carpal joint was the midcarpal joint (42%). CONCLUSIONS: Recognizing carpal abnormalities on radiographs is helpful for the diagnosis of KBD and the evaluation of the severity of the disease. The more severe the KBD, the more likely that the carpal bones will be involved. The capitate and hamate are frequently affected if the disease involves the carpal bones.     

Limitations of MR imaging in the diagnosis of peripheral tears of the triangular fibrocartilage of the wrist.

OBJECTIVE: The treatment of peripheral tears of the triangular fibrocartilage complex is radically different from the more typical central, degenerative tears. To our knowledge, no reports in the imaging literature specifically evaluate tears of the ulnar attachment of the triangular fibrocartilage complex. We evaluated the accuracy of MR imaging in these patients. MATERIALS AND METHODS: Eighty-six MR imaging examinations of the wrist (41 indirect MR arthrograms and 45 unenhanced MR images) were evaluated: 20 wrists with surgically confirmed peripheral triangular fibrocartilage complex tears and 66 wrists with surgically documented normal ulnar attachment. These cases were evaluated by three experienced musculoskeletal radiologists, who were unaware of the surgical findings, to assess the presence of peripheral triangular fibrocartilage complex tears or fluid signal at the ulnar attachment of the triangular fibrocartilage complex. RESULTS: The sensitivity for evaluation of the peripheral triangular fibrocartilage complex tear was 17%, with a specificity of 79% and an accuracy of 64%. High signal intensity at the ulnar insertion of the triangular fibrocartilage complex as a marker for tear showed a sensitivity of 42%, a specificity of 63%, and an accuracy of 55%. Weighted kappa values revealed only fair agreement among the three observers. CONCLUSION: MR imaging does not adequately reveal the peripheral attachment of the triangular fibrocartilage complex.     

Inflammatory arthritis-like and other MR findings in wrists of asymptomatic subjects

Objective To describe magnetic resonance (MR) imaging findings in the wrists of asymptomatic subjects that might be confused with pathologic findings.Design MR examination of the dominant wrist was performed in 30 asymptomatic volunteers aged 22–49 years using pre-contrast and post-contrast sequences in the coronal and axial planes. The bases of the metacarpals, the carpus and the distal radius and ulna were evaluated by two musculoskeletal radiologists for lesions, notches, blood vessels and synovial enhancement.Results There were 24 bright osseous lesions (erosions, intraosseous ganglia, oedema or cysts) in 14 subjects. Intraosseous blood vessels were seen in all but one wrist examined, most commonly in the capitate and lunate bones. Enhancement was present in 26 of 27 notches identified at the base of the second metacarpal and less commonly in the capitate, hamate and triquetral notches. A small joint effusion was present in 14 subjects. Joint or soft-tissue enhancement was identified in 16 wrists.Conclusions Many MR abnormalities and variants may be detected in the wrists of asymptomatic subjects. Many of these could be confused with pathologic findings usually associated with inflammatory arthritis.Partial funding provided by the Royal Australian and New Zealand College of Radiologists College Research Fund.     

Computed tomography of wrist trauma

We devised a rapid and sensitive computed tomography (CT) method to assess the acutely injured wrist, healing carpal fractures and post-traumatic osteonecrosis, when the plain films offer insufficient information. The wrist is positioned in a simple reverse-L-shaped Perspex immobilizer. With the scaphoid as the center of the arc and the long axis of the distal radius as the reference 0 degrees line, sequential coronal scans of the wrist were done in 10 degrees increments in an arc of 40 degrees to give 0 degrees, 10 degrees, 20 degrees, 30 degrees and 40 degrees scans. The 0 degrees and 10 degrees arc scans were best for evaluating the distal radius and ulna and soft tissues, the 10 degrees and 20 degrees scans for the carpal bones other than the scaphoid, and their relation to each other, the 30 degrees and 40 degrees scans, parallel to the long axis of the scaphoid, for fractures of the scaphoid and the hook of the hamate. In addition the 40 degrees scan offered an excellent carpal tunnel view. In 22 patients examined for wrist trauma CT was found to be more accurate than plain films and plain-film tomography in determining the presence of a fracture (4 scaphoid and 1 distal radius), in assessing the degree of osseous union (12) and in evaluating intercarpal fusion (2). In addition CT detected avascular necrosis of the lunate in two patients and erosions of the scaphoid and distal radius attributed to rheumatoid arthritis in one.     

磁共振扩散加权成像对结肠癌术后肝转移灶检出的临床研究

目的:探讨磁共振扩散加权成像对结直肠癌肝转移的诊断价值。方法:27例结直肠癌患者行肝脏磁共振扩散加权成像、非增强磁共振和多层CT检查。阅片前告知阅片者患者为结直肠癌术后,但不提供临床病史和既往影像学资料。结果:多层CT、非增强磁共振和扩散加权成像对肝转移灶的敏感度分别为72%(45/63)、76%(48/63)和93%(58/63),扩散加权成像对肝转移灶具有更高的敏感度且与多层CT和非增强MRI相比,差异有显著性意义。扩散加权成像对肝转移患者敏感度最高(82%),而多层CT和非增强MRI分别为77%和66%。结论:磁共振扩散加权成像对结直肠癌肝转移灶的检出率高于多层CT和非增强MRI。     

Ultrasound guidance for puncture and injection in the radiocarpal joint

Background: The use of intra-articular contrast agent has been shown to increase the diagnostic accuracy of wrist magnetic resonance (MR) in patients with suspected trauma of the wrist ligaments. Traditionally, the contrast agent has been applied under fluoroscopic guidance.

Purpose: To present a method based on ultrasound guidance for the injection of intra-articular contrast agent in wrist MR.

Material and Methods: One hundred eight patients (56 female and 52 male, mean age 36 years) referred for wrist MR arthrograms due to suspected ligament rupture were included in this retrospective study. The preferred injection point is about 1 cm distal to Lister's tubercle in the distal radius. A correct positioning of the injection needle can be ensured using ultrasound guidance.

Results: Using this technique, the injection was intra-articular in 93.5% of the 108 injections over a 2-year learning period.

Conclusion: Ultrasound guidance of the contrast injection in radiocarpal MR arthrograms is a cost-effective and safe alternative to fluoroscopically guided procedures. Furthermore, the use of ultrasound guidance provides clues about possible fluid collections within the joint.     

Early MRI in the management of clinical scaphoid fracture

The incidence of MRI detected scaphoid and other wrist fractures was determined in a clinical setting in patients with suspicion of scaphoid injury and negative initial radiographs. The influence on subsequent patient management was examined. Patients attending Accident and Emergency over a 25 month period with suspected scaphoid fracture and normal scaphoid series plain films were referred for wrist MRI. Scans comprising T(1) weighted spin echo and short tau inversion recovery (STIR) coronal sequences were performed in a dedicated extremity low field MRI scanner within 14 days of injury. Subsequent effects on patient management were ascertained by clinician completed questionnaire. 195 patients were scanned. There were 37 scaphoid fractures (19%), 28 distal radius fractures (14%), 9 fractures of other carpal bones (5%) and 119 studies with no fracture. The management of 180 patients (92%) was altered as a result of the MRI scan. Occult fractures are present in almost two fifths of patients with suspected scaphoid fracture and normal initial plain films. Half of these are scaphoid fractures. MRI allows an early definitive diagnosis to be made, changing patient management in over 90% of cases and should be regarded as the gold standard investigation in this population.     

Direct MR arthrography of cadaveric wrists: comparison between MR imaging at 3.0T and 7.0T and gross pathologic inspection

Purpose:

To prospectively evaluate the diagnostic accuracy of magnetic resonance (MR) arthrography for the detection of articular cartilage abnormalities at 3.0T and 7.0T in cadaveric wrists.

Materials and Methods:

MR imaging (MRI) was performed in nine cadaveric wrists (four right wrists, five left; mean age, 81.0 ± 9.8 years) after the intraarticular administration of gadoterate‐meglumine. A 3.0T and 7.0T MR system, mechanically identical custom‐built 8‐channel wrist coil arrays and a similar standard MRI protocol, were used. MR images were evaluated for visibility of articular cartilage surfaces, presence of cartilage lesions, and confidence of diagnosis by two independent radiologists. Open pathologic inspection served as reference standard. Sensitivity, specificity, negative predictive values (NPV) and positive predictive values (PPV), and accuracy (ACC) were calculated. Wilcoxon signed rank test was used to assess differences in the diagnostic performance.

Results:

Visibility of articular cartilage surfaces was significantly better at 3.0T than at 7.0T (P < 0.001). Mean sensitivity, specificity, NPV, PPV, ACC for both readers were 63%, 90%, 85%, 76%, 82% at 3.0T, respectively, and 52%, 91%, 82%, 75%, 79% at 7.0T. The difference between 3.0T and 7.0T was not significant for reader 1 (P = 0.51), but was significant for reader 2 (P = 0.01). The level of confidence was significantly higher at 3.0T than at 7.0T for both readers (P = 0.004; P = 0.03).

Conclusion:

MR arthrography of the wrist at 7.0T is still limited by the lack of commercially available radiofrequency coils and limited experience in sequence optimization, resulting in a significantly lower visibility of anatomy, lower diagnostic accuracy, and level of confidence in judging cartilage lesions compared to 3.0T. J. Magn. Reson. Imaging 2011;. © 2011 Wiley Periodicals, Inc.     

Arthrosis of the lunate-capitate joint

Arthrosis of the lunate-capitate (LC) joint was investigated in 44 wrists from 36 patients. The symptomatology was uncharacteristic and most patients were examined because of pain, swelling or decreased function of the wrist. The LC arthrosis seemed to be secondary to trauma in most patients; 26 wrists had an increased distance between the lunate and scaphoid, indicating a rotatory luxation of the scaphoid; 5 had fracture of the scaphoid with pseudarthrosis; one had a radius fracture healed with volar and ulnar compression and 2 had penetrating trauma to the LC joint. The arthrosis was secondary to pathologic changes in the lunate in 3 patients; lunatomalacia in 2 and a cyst fracturing into the LC joint in one. In 7 wrists arthrosis was found in several carpal joints and the LC arthrosis was one of these.     

Articular cartilage lesions of the glenohumeral joint: diagnostic effectiveness of MR arthrography and prevalence in patients with subacromial impingement syndrome

PURPOSE: To determine the prevalence of articular cartilage lesions in patients with subacromial impingement syndrome and to assess the diagnostic effectiveness of magnetic resonance (MR) arthrography in detecting such cartilage abnormalities. MATERIALS AND METHODS: MR arthrographic images obtained in 52 consecutive patients (mean age, 45.8 years; age range, 17-73 years; 26 male and 26 female patients) were retrospectively evaluated for glenohumeral cartilage lesions. Two experienced musculoskeletal radiologists who were blinded to the arthroscopy report independently analyzed the articular cartilage. Humeral and glenoidal cartilage were assessed separately. The lesions were graded as either subtle or marked. Arthroscopic findings were the standard of reference. Sensitivity, specificity, accuracy, and interobserver agreement were calculated. RESULTS: At arthroscopy, humeral cartilage lesions were found in 15 patients (frequency, 29%). Four lesions were subtle, and 11 were marked. Cartilage lesions of the glenoid were less frequent (eight patients; frequency, 15%): Three were subtle, and five were marked. For reader 1 and reader 2, respectively, sensitivity of MR arthrography for humeral cartilage lesions was 53% and 100%, specificity was 87% and 51%, and accuracy was 77% and 65%; sensitivity for glenoidal cartilage lesions was 75% and 75%, specificity was 66% and 63%, and accuracy was 67% and 65%. Interobserver agreement for the grading of cartilage lesions with MR arthrography was fair (humeral lesions, kappa = 0.20; glenoidal lesions, kappa = 0.27). CONCLUSION: Glenohumeral cartilage lesions are found in up to one third of patients referred for MR arthrography for subacromial impingement syndrome. The performance of MR arthrography in the detection of glenohumeral cartilage lesions is moderate.     

Wrist Trauma: More Than Bones

Acute and subacute wrist trauma predominantly consist of fractures of the distal radius in elderly patients and most frequently carpal fractures (scaphoid, followed by triquetrum and hamatum) and avulsion fractures of the ulnar styloid in younger patients, especially in sports-related injuries but also in work activities. The initial radiographs may miss the fractures and result when untreated in complications as nonunion, osteonecrosis, and degenerative osteoarthritis.Fractures of the distal radius and of the scaphoid may be associated with ligament injuries, most frequently the scapholunate complex, which are often overlooked at the emergency department. Patients without osseous injuries may present intrinsic and extrinsic ligament tears that may lead to carpal instability when they are clinically and/or radiologically missed.Therefore, in acute and subacute setting, computed tomography may be helpful for the detection of subtle fractures, and magnetic resonance imaging, for the early diagnosis of occult fractures and ligament injuries.     

The long-term effects of force-transmission in an injured wrist, measured with dual-energy X-ray absorphometry: a case report

PURPOSE: To investigate the feasibility of using a dual-energy X-ray absorphometry (DEXA) scan to predict long-term force-transmission patterns in wrists. MATERIAL AND METHODS: Both wrists of a man with morbid Kienb?ck stage IIIa disease of his left wrist (avascular necrosis of the lunate) were examined by a DEXA scan to determine the differences in bone density in the distal radius. RESULTS: In the distal radius of the injured wrist, a shift in bone density was seen toward the scaphoid fossa, which resembles the shift in force-transmission pattern described in force-transmission studies of the wrist. CONCLUSIONS: These differences can be interpreted as a result of an altered force-transmission pattern in the injured wrist.