Synovial joints: evaluation of intraarticular bodies with US

Synovial osteochondromatosis in the subacromial bursa mimicking calcific tendinitis: sonographic diagnosis

Synovial osteochondromatosis is an idiopathic benign metaplasia of the synovial membrane rarely found in an extra-articular bursa. We describe the case of a 55-year-old woman with synovial osteochondromatosis in the subacromial bursa mimicking calcific tendinitis. Plain radiographs showed a radiopaque mass over the middle facet of the greater tuberosity, suggesting calcific tendinitis. Sonography, however, showed a loose body in the subacromial bursa, and no evidence of calcification inside the rotator cuff.

[The usefulness of ultrasonography in synovial disease]

Synovial disease is common in clinical practice and can have different causes. The development of high resolution ultrasonography (US) has led to greater use of US in the study of synovial disease. In this context, US is useful because (1) it can detect not only synovial disease, but also its consequences as tissue damage (erosions); (2) it can guide arthrocentesis when clinical attempts to obtain joint fluid have been unsuccessful, especially in joints that are difficult to access (hips), or sometimes when joint infections are clinically suspected; (3) it enables the efficacy of treatment for synovitis to be evaluated; and (4) it makes it possible to distinguish benign cystic lesions from other tumors. The overall evaluation of synovial disease is based on semiologic criteria that enables these alterations to be classified into four main groups: (a) joint effusion, (b) cystic synovial lesions, (c) intra-articular free bodies, and (d) synovial thickening.

Comparison of MR arthrography with arthroscopy of the hip for the assessment of intra-articular loose bodies

OBJECTIVE

To assess the specificity and sensitivity of MR arthrography of the hip in comparison with arthroscopy for the evaluation of intra-articular loose bodies.

DESIGN

Over a 3-year period, 81 consecutive patients underwent a total of 82 hip arthroscopies by a single orthopedic surgeon for intractable hip pain. Of the 82 arthroscopies, 70 had pre-operative MR arthrograms. Of these, 57 were available for retrospective review, after which they were compared with the operative notes of the subsequent arthroscopies.

RESULTS

Of 82 arthroscopies 16 (20%) demonstrated intra-articular loose bodies, while, in the study group, nine of 57 had loose bodies (16%). There was a total of seven discordant cases (five false negatives and two false positives). The sensitivity of MR arthrography for detection of intra-articular loose bodies was 44%, while the specificity was 96%.

CONCLUSION

While the specificity of MR arthrography for the detection of intra-articular loose bodies was high (96%), the sensitivity was not nearly as good (44%).

Musculoskeletal Sonography: A Dynamic Tool for Usual and Unusual Disorders

OBJECTIVE

The purpose of this study is to illustrate a wide variety of musculoskeletal disorders that can be diagnosed with dynamic sonography.

CONCLUSION

Dynamic sonography is a useful tool for the evaluation of a variety of musculoskeletal disorders. Many of these disorders cannot be diagnosed by any other imaging method.

Ultrasound of the shoulder and elbow

Ultrasound examination of the shoulder and elbow requires careful technique, appreciation of normal anatomy, and appropriate high-end equipment. Ultrasound provides detailed diagnostic information. Its accuracy is comparable to that of MRI in the assessment of the rotator cuff. Ultrasound is cheaper than MRI and is preferred by patients.

Ultrasonography of the lower extremity

Ultrasonography is a useful imaging tool for various soft tissue and joint pathologies affecting the lower extremity. This article reviews the normal sonographic appearance of muscles, tendons, ligaments, nerves, bone, and cartilage. The ultrasound imaging appearance of various pathologic conditions affecting the hip, thigh, knee, lower leg, ankle,and foot are illustrated. The advantages of ultrasonography are highlighted.

Clinical and ultrasonographic findings related to knee pain in osteoarthritis

OBJECTIVES

To determine clinical and sonographic factors associated with painful episodes in patients with knee osteoarthritis (OA).

METHODS

In this cross-sectional controlled study, patients with primary knee OA (ACR criteria) were prospectively placed into two groups. Group A: 81 patients with knee pain during physical activity >or=30 mm in visual analogue scale (VAS) for pain for at least 48 h prior to inclusion; Group B: 20 patients without knee pain from at least 1 month prior to inclusion. Clinical parameters, knee radiographic and ultrasonographic findings were collected. The sonographic study assessed joint effusion in the suprapatellar pouch, infrapatellar superficial and deep bursitis, meniscal lesions, anserine tendinobursitis, and Baker's cyst.

RESULTS

Group A patients tended to be older and heavier women than group B (P<0.05). The most frequent radiographic stage was III (57%) in group A, and I (35%) and II (35%) in group B, showing differences in the distribution of each radiographic stage (P<0.005). The most frequent ultrasonographic finding in group A was suprapatellar effusion (79%), and in group B it was meniscal lesions (40%). Ultrasonographic findings showed in group A a significant increase of suprapatellar effusion (P<0.001) and a tendency towards an increase of Baker's cyst (P=0.06). Suprapatellar effusion, Baker's cyst, and body mass index (BMI) were the factors associated with the appearance of pain after the logistic regression analysis.

CONCLUSIONS

Suprapatellar effusion, Baker's cyst, and higher BMI are more frequent and seem to be risk factors of painful flare in OA of the knee.

Sonography of the knee: intra-articular pathology

MRI is the gold-standard imaging technique for evaluation of the intra-articular structures of the knee, and the use of sonography remains controversial. Sonography nevertheless is a useful alternative in several conditions: Inflammatory joint diseases, where it is appropriate for early diagnosis and follow-up of joint effusion and synovitis; peri-articular masses, where it is the best modality for guidance of needle puncture or biopsy; suspected meniscus or ligament lesion, where it may provide a positive diagnosis but is not sufficient to exclude intra-articular lesions; and loose bodies, where it is an outstanding modality for diagnosing lesions not evident on radiographs.

Ultrasound of the elbow

The elbow is an important synovial hinge joint of the upper extremity. This joint represents a common site of musculoskeletal symptomatology, affecting all age groups. The advantages of ultrasound imaging of the elbow include easy availability, multiplanar capability and the ability to assess structures dynamically. Patient symptomatology and site of maximal tenderness can be directly correlated with imaging findings. Comparison is easily made with the contralateral side. Particular strengths include the ability to assess para-articular structures, such as regional tendons and ligaments, in addition to assessment of joint effusions, loose bodies and regional bursae. With operator experience and excellent technique, ultrasound is a valuable imaging tool for assessment of disorders of the elbow joint.

Imaging of the elbow in the overhead throwing athlete

Elbow injuries in athletes who perform overhead throwing motions often present diagnostic challenges because of the undue stresses and often chronic, repetitive patterns of injury. Accurate and efficient assessment of the injured elbow is essential to maximize functional recovery and expedite return to play. Radiographic evaluation should be tailored to the specific injury suspected and requires a thorough understanding of normal anatomic relationships as well as familiarity with common injuries affecting these athletes.

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.

Detection of intraarticular bodies of the elbow with saline arthrosonography

AIM

To assess whether ultrasound with intraarticular injection of saline increases the detection of intraarticular bodies of the elbow.

SUBJECTS AND METHODS

Twelve patients (age range 21-42 years, mean 29 years; 8 male, 4 female) referred over a 2-year period with an equivocal history of elbow locking and plain radiographs had a joint injection of at least 12 ml of sterile saline during ultrasound examination. No patient had a joint effusion before injection. Surgical correlation was available in six patients.

RESULTS

Ten patients had intraarticular bodies but these were demonstrated only after joint injection in six patients. Arthroscopy performed in six patients confirmed intraarticular bodies in five. Radiographs were falsely positive in one and falsely negative in seven patients.

CONCLUSION

Joint injection improves the sonographic evaluation and conspicuity of small and radiographically occult intraarticular loose bodies in the clinically equivocal elbow. The procedure is simple, quick, well tolerated and reproducible.

Natural progression of osteochondritis dissecans of the humeral capitellum: initial observations

PURPOSE

To determine the earliest findings, subsequent changes, and natural course of osteochondritis dissecans of the humeral capitellum.

MATERIALS AND METHODS

Among 95 patients with osteochondritis dissecans of the humeral capitellum, 16 (mean age, 12.5 years) were selected for this retrospective study because they seemed to have early osteochondritis dissecans and had been followed up without any surgical treatment for 6 months or more (mean, 3.5 years).

RESULTS

The initial imaging appearances of the 16 patients' lesions were divided into two types: localized subchondral bone flattening without fragments in seven, and nondisplaced fragments in nine. Patients with lesion flattening had younger ages and significantly shorter durations of symptoms, and most had open growth plates. In five of the seven with flattening, new bone formed over the flattened bone, and the fragments united after arm motion reduction. In contrast, patients with nondisplaced fragments at clinical presentation had longer durations of symptoms with continued arm motion, and their nondisplaced fragments failed to unite.

CONCLUSION

The earliest feature of osteochondritis dissecans is subchondral bone flattening, over which new bone subsequently forms. The new bone then can unite with the underlying bone. However, if subjected to repetitive forces over a given time, unstable fragments develop. These fragments, even if not yet displaced, are unable to unite.

Ultrasound of the adult hip

The adult hip is a new and challenging site for evaluation with ultrasound (US). Clinically, diseases involving the hip region may be difficult to diagnose without the help of imaging. The hip region is a crossroad for numerous vascular, nervous, and muscular structures that pass between the trunk and the lower extremity. Thus, inflammatory processes and neoplasms may spread to and from the hip, buttock, thigh, pelvis, and retroperitoneum, and trauma may also effect the adjacent areas of the trunk and thigh. Because it is a crossroad, many conditions that are not specific to the hip occur in this area, including inguinal lymphadenopathy, pathology from the abdomen or the genitalia (intestinal hernia, inflammation, and infection), and even referred pain from spinal disorders. The goals of US imaging are the detection and localization of these pathological processes, the differentiation of intra-articular andextra-articular pathology, and the performance of diagnostic and therapeutic interventional procedures. This article reviews the hip anatomy, followed up by a discussion of the US evaluation and differential diagnosis of common pathology occurring in the hip area. This includes joint effusion, arthritis, loose bodies, bursitis, pseudoaneurysm, muscle and tendon diseases, as well as tumor and tumor-like lesions such as hematoma, abscess, and lymphadenopathy.

Ultrasound of the ankle and foot

Ultrasound is an excellent tool for evaluating common ankle problems. it is more economical than MRI and its real-time nature helps in correlating the study with the symptomatic area. US can be used in ankle to evaluate tendons (including tears, tendinitis and tenosynovitis), joints, plantar fascia, ligaments, soft tissue masses, ganglion cysts, Morton's neuroma, and to look for foreign bodies. Power Doppler can be used to evaluate blood flow in acute inflammatory process and in reflex sympathetic dystrophy.

Sonographic assessment of osteochondritis dissecans of the humeral capitellum

OBJECTIVE

The purpose of this study was to determine the efficacy of sonography for revealing osteochondritis dissecans of the humeral capitellum.

SUBJECTS AND METHODS

Twenty-seven patients with capitellar osteochondritis dissecans (27 males; range, 11-20 years; mean age, 14 years) underwent radiography and sonography performed with a 7.5-MHz mechanical sector probe. Lesions were assessed as stable or unstable. The sonographic assessment was compared with radiographic assessment in 27 patients, MR assessment obtained in 10, and surgical findings in 15.

RESULTS

Sonographic assessment agreed with radiographic assessment in 23 of the 27 patients, MR assessment in nine of the 10, and surgical findings in 14 of the 15. Sonography revealed that two lesions, which had been underestimated on radiography, were unstable.

CONCLUSION

Sonography facilitates the assessment of capitellar lesions so that treatment can be optimized.

Foot and ankle sonography

Sonography of the foot and ankle offers many advantages. Currently, sonographic evaluation rivals or exceeds MR imaging for evaluation of tendons, joint and bursal pathology, and specific soft tissue pathology. The advantages of sonographic evaluation provide a strong impetus for applying this modality to imaging of foot and ankle pathology. Those who accept the challenge will have an expanded repertoire to offer in the pursuit of efficient and effective patient care.

Joint sonography

Sonographic evaluation of joint and periarticular pathology clearly has applications in numerous clinical scenarios, not only for diagnosis but in some situations for US-guided biopsy, aspiration, and injections. It is a rapid, inexpensive technique that with adequate equipment, training, and expertise makes it compelling for use as a first-line imaging modality for the assessment of periarticular masses, localized pain, possible infection, joint swelling, as well as posttraumatic articular and periarticular lesions.

Detection of loose bodies in joints

The ability of US to diagnose intra-articular loose bodies greatly depends on a high degree of suspicion of the examiner, related to the knowledge of radiographic and clinical findings. Nowadays, radiography is still the modality of choice when a loose body is suspected on clinical grounds. Plain films are panoramic and not expensive. If a calcified image consistent with a loose body is shown on radiographs, US can be performed to prove its intra-articular location and rule out para-articular calcification. The size, position (recess, bursa), and macroscopic composition (osseous, osteochondral) of loose bodies can be reliably evaluated. Additional findings, including mobility of loose bodies, presence of joint effusion, and synovial proliferation, can also be assessed with US. Detailed knowledge of the normal anatomy of joints and related structures is, of course, an essential requirement to investigate loose bodies. If the fragment is not found in the expected location, other joint recesses and bursae must be explored, because a fragment can change position with time. In addition, the US appearance of loose bodies has to be known by sonographers dealing with the musculoskeletal system because an intra-articular fragment can be found during routine examination of a joint performed before standard radiographs. There are a number of limitations on the clinical usefulness of US in this field. Although US is able to differentiate between single and multiple loose bodies, the exact number of the fragments cannot always be established. In osteochondral fractures, information on the posttraumatic damage to other intra-articular structures, such as ligaments or menisci, cannot be obtained by US. Furthermore, because US can evaluate only a portion of the articular surface, in most patients it is not able to demonstrate the site from which the fragments detach, as well as show their overall size and gross appearance. In conclusion, loose bodies are consistently depicted with US. A high degree of suspicion, knowledge of the radiographic studies, as well as a careful scanning technique, however, are essential to obtain a reliable diagnosis of loose bodies. US is able to support plain films to confirm the intra-articular location of a calcification around a joint. During routine joint examination, US can recognize loose bodies as incidental findings.

Imaging of elbow disorders

Numerous modalities are available for imaging the elbow. Radiographs should be the first imaging procedure performed for evaluation of an elbow abnormality. The use of advanced imaging modalities such as MR imaging, CT, and sonography also is discussed in this article.

Ultrasound appearance of synovial osteochondromatosis of the shoulder

This case report demonstrates the ultrasound appearance of synovial osteochondromatosis of the shoulder, along with plain film radiographic, computed tomographic, and pathologic correlation. Because of recent renewed interest in the use of ultrasonography in the evaluation of musculoskeletal disease, such as rotator cuff arthropathy or suspected intra-articular loose body, opportunities to diagnose synovial osteochondromatosis with this modality have become more frequent.