Carolyn M. Sofka

Magnetic Resonance Imaging After Total Hip Arthroplasty: Evaluation of Periprosthetic Soft Tissue

BACKGROUND The evaluation of periprosthetic osteolysis in patients who have had a total hip arthroplasty is challenging, and traditional imaging techniques, including magnetic resonance imaging and computerized tomography, are limited by metallic artifact. The purpose of the present study was to investigate the use of modified magnetic resonance imaging techniques involving commercially available software to visualize periprosthetic soft tissues, to define the bone-implant interface, and to detect the location and extent of osteolysis. METHODS Twenty-eight hips in twenty-seven patients were examined to assess the extent of osteolysis (nineteen hips), enigmatic pain (five), heterotopic ossification (two), suspected tumor (one), or femoral nerve palsy (one). The results were correlated with conventional radiographic findings as well as with intraoperative findings (when available). RESULTS Magnetic resonance imaging demonstrated the bone-implant interface and the surrounding soft-tissue envelope in all hips. Radiographs consistently underestimated the extent and location of acetabular osteolysis when compared with magnetic resonance imaging. Magnetic resonance imaging also disclosed radiographically occult extraosseous soft-tissue deposits that were similar in signal intensity to areas of osteolysis, demonstrated the relationship of these deposits to adjacent neurovascular structures, and allowed further visualization of hypertrophic synovial deposits that accompanied the bone resorption in twenty-five of the twenty-eight hips. CONCLUSIONS Magnetic resonance imaging is effective for the assessment of the periprosthetic soft tissues in patients who have had a total hip arthroplasty. While not indicated for every patient who has pain at the site of an arthroplasty, these techniques can be effective for the evaluation of the surrounding soft-tissue envelope as well as intracapsular synovial deposits and are more effective than radiographs for the detection and evaluation of osteolysis, thus aiding in clinical management.

Use of ultrasonographic guidance in interventional musculoskeletal procedures : A review from a single institution

We have evaluated the utility of ultrasonographic guidance for intervention in the musculoskeletal system. All interventional musculoskeletal procedures using ultrasonographic guidance performed at our institution from July 1998 through November 1999 were reviewed. Examinations were performed using either a linear or curved phased array transducer, based on depth and local geometry. The choice of needle was likewise optimized for specific anatomic conditions. One hundred ninety‐five procedures were performed on 167 patients from July 1998 through November 1999. Thirty‐one procedures had magnetic resonance correlation within 6 months beforehand. Excluding large‐joint aspirations and injections, we found that 180 of the procedures were more readily performed using ultrasonography than any other imaging modality. These included therapeutic injections into tendon sheaths (biceps, flexor digitorum longus, posterior tibial, and iliopsoas), Mortons neuromas, plantar fascia, wrist ganglia, and tarsal tunnel cysts; peritendinous hamstring injections; and synovial cyst and muscle biopsies. In all cases, the target of interest was identified easily with ultrasonography, and needle position was documented readily. Also in all cases, aspiration or medication delivery to the site of interest was observed during real time and was documented on postprocedure images of the area. No significant complications (e.g., bleeding, infection, and neurovascular compromise) were encountered during or immediately after any procedure. Ultrasonography is a readily available imaging modality useful for guiding interventional procedures in the musculoskeletal system. The ability to document exact needle placement in real time confirms accurate placement of therapeutic injections, fluid aspiration, and soft tissue biopsies.

Percutaneous ultrasound-guided injections in the musculoskeletal system.

Ultrasound guidance is an accurate method for the delivery of therapeutic injections in the musculoskeletal system. The visualization of the needle in real time allows for reliable placement of the needle tip in the tendon sheath, bursa, or joint of interest. Both superficial and deep articulations and tendon sheaths can be targeted for diagnostic or therapeutic interventions. In addition, intratendinous calcifications, the plantar fascia, and interdigital (Mortons) neuromas can also be visualized and injected directly under real-time guidance. Performing percutaneous interventions with ultrasound ensures accurate needle tip placement and helps direct the needle away from other regional soft-tissue structures such as nearby neurovascular bundles.

Magnetic Resonance Imaging of Adhesive Capsulitis: Correlation with Clinical Staging

The purpose of this study was to evaluate non-contrast magnetic resonance imaging (MRI) findings of adhesive capsulitis and correlate them with clinical stages of adhesive capsulitis. This will hopefully define a role for shoulder MR imaging in the diagnosis of adhesive capsulitis as well as in potentially directing appropriate treatment. Forty-seven consecutive non-contrast magnetic resonance imaging examinations of 46 patients with a clinical diagnosis of adhesive capsulitis were retrospectively reviewed and correlated with clinical staging. Specific MRI criteria correlated with the clinical stage of adhesive capsulitis, including the thickness and signal intensity of the joint capsule and synovium as well as the presence and severity of scarring in the rotator interval. Routine MRI of the shoulder without intraarticular administration of gadolinium can be used to diagnose all stages of adhesive capsulitis, including stage 1, where findings may be subtle on clinical examination. We believe that future studies assessing the role of MRI in guiding the initiation of appropriate treatment should be undertaken.

Haglund's Syndrome: Diagnosis and Treatment Using Sonography

Haglunds syndrome is a cause of retrocalcaneal pain. The clinical diagnosis of Haglunds syndrome is often confusing as the clinical picture may mimic other causes of hindfoot pain such as isolated retrocalcaneal bursitis or hindfoot involvement from more systemic arthropathies such as Reiters syndrome or rheumatoid arthritis. With the increasing frequency of employing sonography as a diagnostic tool in the evaluation of foot and ankle pathology, recognition of the sonographic appearance of Haglunds complex is important. We report a case of Haglunds syndrome diagnosed and treated with sonography.

Teres minor denervation on routine magnetic resonance imaging of the shoulder

ObjectiveTo try to define an association between clinical history and the finding of isolated teres minor denervation on routine magnetic resonance (MR) examination of the shoulder.DesignA retrospective review of all shoulder MR examinations performed at our institution over a 2-year period (n=2,563)PatientsAll patients and MR examinations demonstrating isolated denervation of the teres minor muscle as determined by review of this subset of patients (n=61)ResultsA 3% incidence of isolated teres minor denervation was found. No patient had a clinical history concerning the classic quadrilateral space syndrome, and no patient had a structural lesion in the quadrilateral space.ConclusionsIsolated teres minor denervation is not an uncommon finding on routine shoulder MR imaging and may be associated with pathology other than a structural lesion in and about the axillary neurovascular structures, such as rotator cuff injuries and traction injury on the axillary nerve sustained during a glenohumeral joint translational event.

Ultrasound diagnosis of chondrocalcinosis in the knee.

The radiographic diagnosis of calcium pyrophosphate dihydrate (CPPD) deposition disease is usually made by observing calcifications in the articular cartilage of large joints or, in the knee, noting calcification in the menisci. Sonography is useful in evaluating the patellofemoral joint, including the trochlear cartilage, which is often difficult to image adequately on conventional radiographs, as true tangential views of the patellofemoral joint may be difficult to obtain. We describe a case of sonographic detection of cartilage calcification in the trochlea of the knee which was radiographically occult.

Detection of muscle atrophy on routine sonography of the shoulder.

Objective. To describe the utility of sonography in visualizing muscle atrophy during routine sonographic examination of the shoulder for evaluation of the rotator cuff tendons. Methods. A retrospective review of 199 shoulder sonographic examinations performed by 2 musculoskeletal radiologists trained in musculoskeletal sonography with knowledge of the typical sonographic findings of muscle atrophy was performed. Reports were reviewed for the presence of muscle atrophy. If atrophy was present, the reports from those examinations were rereviewed for concomitant rotator cuff abnormalities. Results. Forty‐five examinations (23%) showed atrophy in at least 1 muscle on the basis of the criteria of increased echogenicity and decreased bulk. There were a total of 81 individual muscles that showed atrophy, with the following distribution: 16% supraspinatus (n = 13), 31% infraspinatus (n = 25), 36% teres minor (n = 29), 2% subscapularis (n = 2), and 6% biceps brachii (n = 5). In 34 of the 45 examinations with muscle atrophy, there were 57 concomitant full‐thickness tendon tears: 64% supraspinatus (n = 29), 38% infraspinatus (n = 17), 7% subscapularis (n = 3), 0% teres minor (n = 0), 16% long head of biceps (n = 7), and 2% deltoid (n = 1). Conclusions. Although primary sonographic evaluation of the painful shoulder concentrates on the tendons of the rotator cuff, we suggest that examination of the muscles should become a standard component of the comprehensive shoulder sonographic examination, particularly given the potential clinical implications of muscle atrophy on the outcome of rotator cuff surgery.

Dermatomyositis and calcific myonecrosis in the leg: ultrasound as an aid in management

Calcific myonecrosis, often reported in the setting of prior trauma or compartment syndrome, has traditionally been treated with surgical debridement; however, these cases are often complicated by poor wound closure and poor healing. Serial percutaneous aspirations, instead, have been proposed as an alternative treatment option. This is the first report, to our knowledge, of the use of ultrasound guidance in the aspiration of calcific myonecrosis as an aid in management.

Imaging of elbow injuries in the child and adult athlete

Because of the often complex and sometimes poorly remembered history of trauma to the elbow, imaging beyond conventional plain film radiographs is often needed. Usually, this consists of high-resolution MR imaging to evaluate the articular cartilage, supporting ligaments, and tendons about the elbow. Sonography, however, can also be used, especially when there is a targeted clinical question as to the presence of epicondylitis, or to provide guidance for diagnostic or therapeutic injections.