Utility of MR arthrography in the diagnosis of adhesive capsulitis.

OBJECTIVE: Arthrographically, adhesive capsulitis is characterized by decreased joint volume; histologically, the capsule and synovium are thickened. We therefore compared using MR arthrography the joint volumes and capsule/synovial thickness of patients with and without adhesive capsulitis in order to assess the utility of MR arthrography in diagnosing adhesive capsulitis. DESIGN AND PATIENTS: The 1.5 T MR arthrography images of 28 subjects with (n=9) and without (n=19) adhesive capsulitis were compared. Adhesive capsulitis was diagnosed when there was an injected glenohumeral joint volume of less than 10 ml. Two masked observers working in consensus assessed the images for the relative amount of fluid in the biceps tendon sheath and axillary recess, corrugation at the margin of the capsule, capsule/synovial thickness, abnormalities of the rotator interval capsule, and for the presence of a cuff tear. RESULTS: There was a trend towards differences in capsular and synovial thickness (P>0.07) between the subjects with and without adhesive capsulitis; however, the controls had thicker synovium/capsules. Surprisingly, the amount of fluid in the axillary recess and biceps tendon sheath was not significantly different between the groups (P>0.25). There were more tears of the rotator cuff in controls than in patients with adhesive capsulitis (6, 3 vs 1, 1: complete, partial). Also, both corrugation (7 vs 0) and interval abnormalities (7 vs 0) were more common in the controls. CONCLUSION: There appear to be no useful MR arthrographic signs of adhesive capsulitis. Capsular/synovial thickness, static fluid volume, and the presence of corrugation are inconclusive as MR arthrographic signs for distinguishing shoulders with adhesive capsulitis from those without.

MR imaging of plantar fasciitis: edema, tears, and occult marrow abnormalities correlated with outcome.

OBJECTIVE: We sought to evaluate various MR imaging signs of plantar fasciitis and to determine if a difference in these findings exists between clinically typical and atypical patients with chronic symptoms resistant to conservative treatment. CONCLUSION: We found signs on MR imaging that, to our knowledge, have not been described in the scientific literature for patients with plantar fasciitis. These signs included occult marrow edema and fascial tears. Patients with these manifestations seemed to respond to treatment in a manner similar to that of patients in whom MR imaging revealed more benign findings.

The cost-effectiveness of routine pelvic radiography in the evaluation of blunt trauma patients.

OBJECTIVE: . To determine the cost-effectiveness of routine protocol-driven pelvic radiography in the evaluation of blunt trauma patients. DESIGN AND PATIENTS: A retrospective review was performed on 319 blunt trauma patients who underwent protocol-driven pelvic radiography to record the frequency of pelvic fracture. Medical records of the patients in whom fractures were identified radiographically were then examined to determine the clinical suspicion of injury prior to radiography. Using Medicare reimbursement data, the cost-effectiveness of routine pelvic radiography was calculated in terms cost per pelvic radiograph with evidence of fracture. These values were then compared with literature values of other screening studies, namely mammography and colonoscopy. RESULTS: Thirty-eight of 319 patients (11.9%) were found to have fractures identified on routine pelvic radiography. Using the 1997 Medicare reimbursement charge of $27.79 for a single anteroposterior radiograph of the pelvis, the total cost of performing these 319 trauma protocol-driven studies was calculated as $8865.01. The cost per protocol-driven pelvic radiograph with evidence of pelvic fracture was subsequently determined to be $233.29. Only 18 (47.4%) of these 38 patients were suspected to have pelvic fracture on the basis of the clinical findings alone. CONCLUSIONS: Trauma protocol-driven pelvic radiography is a necessary and cost-effective means of identifying acute pelvic injury in all trauma patients regardless of clinical presentation.

Efficacy of magnetic resonance imaging in the evaluation of posterior cervical spine fractures.

STUDY DESIGN: A retrospective study using two independent, blinded musculoskeletal radiologists to evaluate the sensitivity, specificity, and predictive value of cervical spine magnetic resonance imaging in detecting posterior element fractures of the cervical spine. OBJECTIVE: To evaluate the sensitivity, specificity, and predictive value of magnetic resonance imaging, using computed tomographic scanning as the gold standard, in the diagnosis of posterior element cervical spine fractures. SUMMARY OF BACKGROUND DATA: Few investigators have evaluated the accuracy of magnetic resonance imaging in the determination of cervical spine fractures. METHODS: From January 1994 through June 1996, 75 cervical spine fractures in 32 patients were confirmed by computed tomography. Two musculoskeletal radiologists who were blinded to the clinical history and presence or absence of cervical injury among the study population, independently evaluated each cervical magnetic resonance image recording the presence or absence of soft tissue or bony injury. RESULTS: The overall sensitivity and specificity rates for the diagnosis of a posterior element fracture by magnetic resonance imaging was 11.5% and 97.0%, respectively. The positive predictive value for this group was 83%, and the negative predictive value was 46%. In reference to anterior fractures, the sensitivity was 36.7% and the specificity 98%. Positive and negative predictive values were 91.2% and 64%, respectively. CONCLUSIONS: Magnetic resonance imaging was not effective in recognizing bony injury to the cervical spine and in particular was not as sensitive or as specific as computed tomography in identifying cervical spinal fractures. Computed tomography remains the study of choice for the detection and precise classification of bony injuries to the cervical region, especially when plain radiographs are difficult to evaluate. Magnetic resonance imaging, although not as effective as computed tomography in defining specific bony disorders, remains the gold standard in the evaluation of spinal cord injury, occult vascular injury, and intervertebral disc disruption (hyperextension injury), including herniation and other soft tissue disorders (hematoma, ligament tear).

MR imaging of inflammatory joint diseases of the foot and ankle.

Pain affecting the foot and ankle is a common complaint frequently attributable to inflammatory joint diseases. Although conventional radiography is regarded as the initial step in the diagnostic investigation, MR imaging may contribute to further evaluation of these patients due to the direct visualization of the inflammatory soft tissue formed in the disease and its effects on bone, cartilage and para-articular structures. The high spatial resolution of MR imaging combined with tissue characterization often allows initial detection of inflammatory joint abnormalities at a stage that precedes radiographic evaluation. The typical MR appearance of certain inflammatory joint disorders may be helpful in narrowing the wide differential diagnosis. Furthermore, MR imaging can be used for an exact assessment of the extent of the disorder as well as its complications. Accurate diagnostic information can guide the clinician in further diagnostic tests and implementation of proper therapeutic treatment.

The cost-effectiveness of oblique radiography in the exclusion of C7-T1 injury in trauma patients.

OBJECTIVE: The purpose of our study was to compare the cost-effectiveness of bilateral oblique radiography with that of CT for excluding C7-T1 injury in trauma patients. MATERIALS AND METHODS: Using a historical cohort model, we retrospectively studied two distinct groups of trauma patients. In the first group, which included 196 patients, CT was performed to show C7-T1 anatomy when this region was not adequately revealed on initial three-view cervical spine radiography. In the second group, which included 129 patients, routine three-view radiography was complemented by bilateral oblique views. If these five views failed to adequately reveal C7-T1 anatomy, CT was then performed to show the cervicothoracic junction. Using Medicare reimbursement data, we then compared the cost-effectiveness of CT with that of oblique radiography in terms of cost per cervical spine imaged completely to the level of C7-T1. RESULTS: In the first group, 50 (26%) of 196 patients underwent CT when C7-T1 anatomy was not adequately revealed on routine three-view cervical spine radiography. In the second group, only 17 (13%) of the 129 patients required CT when five-view radiography failed to adequately reveal C7-T1 anatomy. This difference was statistically significant (p < .01). The cost per completely imaged cervical spine was $92.00 when bilateral oblique radiographs were routinely obtained, compared with $116.28 per completely imaged cervical spine when these views were not obtained. CONCLUSION: Because bilateral oblique radiography appears to be cost-effective for the exclusion of cervical spine injuries, we suggest that it be performed routinely.

Disorders of the hallux sesamoid complex: MR features.

Numerous painful conditions can affect the first metatarsophalangeal-sesamoid joint complex. Symptoms can be of sudden or insidious onset, and be of acute or chronic duration. Although conventional radiography is recognized as the initial diagnostic procedure for these symptoms, there is often a need to proceed to MR imaging. MR imaging is sensitive and can be utilized in the investigation of the hallux sesamoid complex to differentiate soft tissue from osseous pathology. Synovitis, tendonitis, and bursitis can be distinguished from bony abnormalities such as sesamoid fracture, avascular necrosis, and osteomyelitis. An understanding of MR imaging features and techniques will result in the highest diagnostic yield. Early and accurate diagnosis of sesamoid complex disorders can guide the physician to the appropriate clinical management and prevent potentially harmful longstanding joint dysfunction.

Helical CT of calcaneal fractures: technique and imaging features.

Since the degree of comminution, fracture alignment, and articular congruity of intra-articular calcaneal fractures are important determinants in surgical treatment and patient prognosis, we review helical computed tomographic (CT) technique and features for detecting and assessing the extent of acute calcaneal fractures. Helical CT can be used to classify these fractures and facilitate the surgeon's understanding of the anatomy and position of the fracture components in all orthogonal planes independently of the patient's condition, foot placement in the CT gantry, or other injuries.

Distal fibular notch: a frequent manifestation of the rheumatoid ankle.

OBJECTIVE: To describe the distal fibular notch, an infrequently described manifestation of rheumatoid arthritis, and to speculate on its etiology through gross dissection, histologic correlation and MR imaging. DESIGN AND PATIENTS: One hundred and twenty-one conventional ankle radiographs were obtained and reviewed in 76 patients with clinically diagnosed rheumatoid arthritis. Additional imaging of three ankles was obtained utilizing CT and MR imaging. In addition to evaluating erosive changes, note was made of the presence and location of a well-defined scalloped defect along the medial border of the distal fibula. Ankle specimen dissection and histoanatomic examination was performed in an attempt to determine the exact pathogenesis of this fibular notch. RESULTS: The distal fibular notch was identified in 52 of 121 ankles (43%). Seventy-five percent of notches were syndesmotic and extended down to the horizontal ankle joint level, while 25% of notches were syndesmotic with extension below the joint. The majority of ankles (79%) demonstrated coexistent marginal erosions and/or joint narrowing. Ankle specimen dissection revealed a single-celled synovial fold within the distal tibiofibular syndesmotic recess without underlying articular cartilage extension. CONCLUSION: The fibular notch within the distal tibiofibular syndesmosis is a frequent manifestation of rheumatoid arthritis and appears to result from synovial proliferation rather than from mechanical instability.

Helical CT of talar fractures.

Since the degree of comminution, fracture alignment, and articular congruity of talar fractures are important determinants of treatment, we review the helical CT technique for detecting and assessing the extent of acute talar fractures. Helical CT can be used to classify talar neck fractures which often cannot be determined by radiography. It is also useful in detecting posterior process, lateral process, and avulsion fractures, as well as acute osteochondral fractures. Multiplanar CT using 1-mm acquisitions allows optimal evaluation, detects fractures initially missed on radiographs, and determines further extent of fractures.