Chronic knee pain in adults - a multimodality approach or which modality to choose and when? Poster No.: P-0157 Congress: ESSR 2013 Type: Authors: Keywords: DOI: Scientific Exhibit E. Ilieva, V. Tasseva, G. Garvanska-Koleva; Sofia/BG Education and training, Education, Ultrasound, Plain radiographic studies, MR, Musculoskeletal joint, Musculoskeletal bone 10.1594/essr2013/P-0157 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. www.essr.org Page 1 of 9
Purpose To overview the most common causes of chronic knee pain in the adult patient; to compare the main modalities (plain radiograph, ultrasound, MRI) used to image the knee pathology in chronic pain with their advantages and disadvantages; to emphasize when and where ultrasound and MR-imaging could be interchangeable and to suggest an appropriate diagnostic imaging algorithm. Methods and Materials Chronic knee pain is most commonly caused by arthritis, bursitis and cystic lesions around the joint, tendon, ligament or meniscus pathology, cartilage pathology, chronic infection, osteonecrosis (avascular necrosis), stress fractures, and avulsion injuries. Radiographs are used primarily to evaluate osseous structures. Soft tissue injuries and abnormalities, effusions and popliteal cysts can also be seen or inferred on plain film but are better defined by other modalities. On ultrasound both extra- and intra-articular structures can be examined. The technique is dynamic, inexpensive, and readily available. Correlation can be made with the patient's point of maximal tenderness as well as comparison with the contralateral side. Ultrasound poorly visualizes the weight-bearing portions of the knee and is highly dependent on the operator's experience. MRI is the study of choice when assessing internal derangement of the knee (ligament or meniscus tear, tendon injury, effusions and cartilage injury). It is non-invasive, does not use ionizing radiation, gives multiplanar images, and provides best imaging of soft-tissue structures. Based on the MR results the patient management may be altered from surgical to non-surgical - a cost-saving approach to knee pain. Disadvantages of the modality include its high price, prominent susceptibility to artefacts from metal and motion, as well as some contraindications (pacemakers and claustrophobia). Images for this section: Page 2 of 9
Fig. 3: Chronic knee pain, knee joint ultrasound - calcifications in the quadriceps tendon Page 3 of 9
Fig. 4: Chronic knee pain, knee joint ultrasound - Baker's cyst (red star) with septations (blue star) Page 4 of 9
Fig. 5: Chronic knee pain, knee joint ultrasound with Doppler- synovial thickening with vascularization, joint effusion Page 5 of 9
Fig. 6: Chronic knee pain, MRI, sagittal PD TSE with fat saturation - ACL mucoid degeneration (red star), suprapatellar joint effusion (blue star), subchondral cysts (green star), quadriceps tendinosis (yellow star) Page 6 of 9
Fig. 7: Chronic knee pain, MRI sagittal PD TSE with fat saturation - Baker's cyst with thin septations (yellow star), degenerative tear of the posterior horn of the medial meniscus (red arrow), synovial thickening (blue star) Page 7 of 9
Results For most appropriate management of the patient with chronic knee pain a correlation of the imaging findings with patient's history and clinical examination is mandatory. 1. Plain radiography is the first step in the knee evaluation. It best depicts the osseous changes in chronic knee pain due to degenerative osteoarthritis (joint space narrowing, sclerosis of the bony articular surface, osteophyte formation, subchondral cysts, articular loose bodies) or due to other osseous pathology as osteonecrosis, stress fractures, avulsion injuries. 2. If joint effusion, popliteal cyst or calcifications in the insertion of muscle tendons and ligaments are seen on X-Ray additional assessment with ultrasound could be done. The sonographic examination will better appreciate the size of the joint effusion and the popliteal cyst, other cystic or fluid-filled bursae, synoviitis, or tendinitis but also can evaluate the popleteal vessels for thrombus, aneurysm and flow. 3. For patients with high clinical suspicion of chronic internal derangements caused by degenerative tear of the meniscus, mucoid degeneration of ACL/PCL or cartilage pathology MRI should be performed which will also give more precise anatomical relation of the sonographic findings. Conclusion Imaging plays an important role in the management of adult patients with chronic knee pain. Radiographs are considered the most appropriate first imaging modality. Ultrasound and MRI contribute significant additional information and could be interchangeable in some instance. Good knowledge of the advantages of the different modalities combined with precise clinical information helps to select the best algorithm for each patient with chronic knee pain. References 1. Bianchi S, Martinoli C: Ultrasound of the Musculoskeletal System, Springer, 2007 2. Jacobson J: Fundamentals of Musculoskeletal Ultrasound, Saunders Elsevier, 2007 3. Chhabra A, Subhawong TK, Carrino JA: Skeletal Radiol. 2011 April; 40(4): 375-387 4. Hayashi et al: Arthritis Research & Therapy 2010, 12:R172 Page 8 of 9
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