• Pavlov H, Dalinka MK, Alazraki NP, Daffner RH, DeSmet AA, El-Khoury GY, KNeeland JB, Manaster BJ, Rubin DA, Steinbach LS, Weissman BN, Haralson RH III, Expert Panel on Musculoskeletal Imaging. Nontraumatic knee pain. [online publication]. Reston (VA): American College of Radiology (ACR); 2005. 9 p. [44 references]

This is the current release of the guideline.

This guideline updates a previous version: Pavlov H, Dalinka MK, Alazraki N, Berquist TH, Daffner RH, DeSmet AA, el-Khoury GY, Goergen TG, Keats TE, Manaster BJ, Newberg A, Haralson RH, McCabe JB, Sartoris D. Nontraumatic knee pain. American College of Radiology. ACR Appropriateness Criteria. Radiology 2000 Jun;215(Suppl):311-20.

The appropriateness criteria are reviewed annually and updated by the panels as needed, depending on introduction of new and highly significant scientific evidence.

ACR Appropriateness Criteria®

Clinical Condition: Nontraumatic Knee Pain

Variant 1: Child or adolescent - nonpatellofemoral symptoms. Mandatory minimal initial exam.

Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.

Variant 2: Child or adult: patellofemoral (anterior) symptoms. Mandatory minimal initial exam.

Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.

Variant 3: Adult: nontrauma, nontumor, nonlocalized pain. Mandatory minimal initial exam.

Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.

Variant 4: Child or adolescent: nonpatellofemoral symptoms. Initial AP and lateral radiographs nondiagnostic (demonstrate normal findings or a joint effusion).

Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.

Variant 5: Child or adult. Patellofemoral (anterior) symptoms. Initial AP, lateral, and axial radiographs nondiagnostic (demonstrate normal findings or a joint effusion).

Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.

Variant 6: Adult. Nontrauma, nontumor, nonlocalized pain. Initial AP and lateral radiographs nondiagnostic (demonstrate normal findings or a joint effusion).

Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.

Variant 7: Child or adolescent. Nonpatellofemoral symptoms. Initial AP and lateral radiographs demonstrate osteochondral injuries (fracture/osteochondritis dessicans or a loose body).

Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.

Variant 8: Child or adult. Patellofemoral (anterior) symptoms. Initial AP, lateral, and axial radiographs demonstrate degenerative joint disease and/or chondrocalcinosis.

Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.

Variant 9: Adult. Nontrauma, nontumor, nonlocalized pain. Initial AP and lateral radiographs demonstrate degenerative joint disease (uni- to tri- compartmental sclerosis, hypertrophic spurs, joint space narrowing, and/or subchondral cysts).

Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.

Variant 10: Adult. Nontrauma, nontumor, nonlocalized pain. Initial AP and lateral demonstrates inflammatory arthritis (diffuse tricompartmental joint space narrowing and large joint effusion).

Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.

Variant 11: Adult, nontrauma, nontumor, nonlocalized pain. Initial AP and lateral radiographs demonstrate avascular necrosis.

Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.

Variant 12: Adult, nontrauma, nontumor, nonlocalized pain. Initial AP and lateral radiographs demonstrate evidence of internal derangement (e.g., Peligrini Stieda disease, joint compartment widening).

Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.

Nontraumatic knee pain in children, adolescents, and adults includes localized complaints such as anterior (patellofemoral) pain and diffuse nonlocalized symptoms. The consensus of the committee is that the initial imaging study for nontraumatic knee pain is AP and lateral radiograph. The AP view can be performed with the patient either standing or supine. The lateral view may be performed with the patient non-weight bearing on his or her side with a vertical beam and the knee flexed 30 degrees. If symptoms are localized to the anterior (patellofemoral joint) aspect of the knee, a Merchant or axial (skyline) view of the patellofemoral joint is a mandatory part of the initial evaluation. For patients with diffuse non-localized symptoms, there was no consensus regarding the usefulness of a Merchant or axial view as part of the initial examination.

In elderly patients, the most common source of nontraumatic knee pain is degenerative osteoarthritis. Conventional radiographic diagnosis of degenerative joint disease includes joint space narrowing, osteophytes, subchondral cysts, and sclerosis bordering the joint. Articular cartilage is evaluated indirectly on conventional radiographs by joint space narrowing and changes in the subchondral bone. Routine radiographs are insensitive for assessing articular cartilage in the early stages of osteoarthritis, while in advanced disease, joint space narrowing on radiographs is usually an accurate assessment of cartilage loss. Standing radiographs have been reported to more accurately reflect medial and lateral joint compartment cartilage loss than supine radiographs; however, in the presence of a severe varus or valgus deformity, significant cartilage loss in the compartment that appears wide (due to the alignment deformity) may not be evident. A weight-bearing posterior anterior (PA) radiograph, obtained with knee flexion, has been reported to reflect the cartilage width of the posterior medial and lateral joint compartments more accurately than that a standing view obtained with the knee extended. This view may be indicated in elderly patients with degenerative osteoarthritis when surgical intervention is being planned. Additional imaging studies are not indicated in patients for whom the conventional radiographs are diagnostic of degenerative joint disease unless treatment, or surgery, or both are dependent on additional findings such as internal knee derangement or when symptoms are not explained by the radiographic findings (e.g., stress fractures).

Other nontraumatic causes of knee pain in adolescent and adult patients include internal knee derangement (meniscal and ligament tears), osteochondritis dissecans, transient osteoporosis, spontaneous osteonecrosis, chronic regional pain syndrome, stress fracture, and inflammatory arthritis. Chronic anterior lateral knee pain may also result from patella tendon--lateral femoral condyle friction syndrome or iliotibial band syndrome (friction syndrome) which can be confirmed/excluded by MRI. In children with nontraumatic knee pain, referred pain from the hip must be entertained.

When initial conventional radiographs are nondiagnostic (normal findings or a joint effusion) and knee symptoms require further imaging, the next indicated study is an MRI exam. MRI is more sensitive than conventional radiographs and provides more specific information compared with radionuclide bone scan. MRI of nontraumatic knee pain may document a joint effusion, communicating synovial cysts, proliferative changes of the synovial membrane, osteophytes, subchondral cysts, articular cartilage loss, meniscal and/or ligamentous tears and/or degeneration, bone marrow edema, fractures, and osteonecrosis. MRI is useful to identify a subchondral insufficiency fracture as the initial injury from which localized osteonecrosis may result and which was otherwise identified as spontaneous osteonecrosis. MRI can also detect osteonecrosis of the medial femoral condyle or of the medial tibial plateau associated with tibial stress fracture. A suprapatellar joint effusion is readily detected on a routine lateral roentgenogram of the knee; however, the extent of a joint effusion, the presence of a communicating synovial (popliteal) cyst, or synovial proliferation is readily identified on MRI. Subchondral cysts are easily detected on MRI because of the tomographic quality, multiplanar imaging capability, and the superb sensitivity to fluid- and fat-containing tissues. Cartilage pathology, both articular and meniscal, can be evaluated directly on MRI, and demonstration depends on the location of the abnormality and the pulse sequences used. Magnetic resonance arthrography (MRA) performed with an intraarticular injection or with an intravenous injection of dilute gadolinium solution to enhance cartilage evaluation has been investigated, but noninvasive MRI has been reported accurate for cartilage abnormalities. Patellofemoral cartilage loss has been reported to be closely associated with chronic knee pain symptoms.

MRI is very sensitive for detection of internal derangement, specifically meniscus and anterior cruciate ligament pathology, and a high prevalence of meniscal degeneration is associated with osteoarthritis. Anterior cruciate ligament (ACL) tears and insufficiency are known to cause osteoarthritic changes in the knee.

Transient osteoporosis is characterized by self-limited pain and demonstrable osteopenia on radiographs within eight weeks after the onset of pain. Spontaneous osteonecrosis of the medial femoral condyle, most often found in middle-aged and elderly females, may have normal radiographs for months, followed by subchondral collapse, fragmentation of the articular cartilage, and progressive osteoarthritis. Bone marrow edema seen on MRI occurs in association with, or independent of, transient osteoporosis, osteonecrosis, and also in association with stress fractures; MRI is highly sensitive for detecting these abnormalities. In patients with conventional radiograph diagnosis of an osteochondral injury such as osteochondritis dissecans or osteonecrosis, an MRI examination may be indicated if clinically additional injury is suspected or when it is necessary to determine the status of the articular cartilage over the area of abnormality. MRI is not indicated to confirm a stress fracture that is evident on the plain roentgenogram.

In patients with conventional radiograph evidence of inflammatory arthritis, the consensus of the panel is that an MRI is usually not indicated for the preoperative differentiation of pannus from effusion or for evaluation of erosion. An aspiration for crystals may be indicated, but arthrographic confirmation is usually not necessary.

When intra-articular pathology is suspected in a patient with claustrophobia, with a large body habitus, or who cannot, for some reason, tolerate an MRI examination; or when there is contraindication to an MRI study such as postsurgical clamps, metal, a pacemaker, or electric implants, a double-contrast arthrogram, possibly followed with CT, may be indicated.

A nuclear medicine bone scan is more sensitive than conventional radiographs for detecting bone changes and degenerative osteoarthritis; however, it is less specific than MRI. A total body nuclear medicine bone scan may be indicated for evaluation of nontraumatic knee pain when there is the clinical suspicion or the possibility of multiple sites of involvement such as in suspected metastatic disease, infarcts, etc.

In summary, the mandatory initial examination for nontraumatic knee pain is an AP and lateral radiograph. In patients with anterior patellofemoral knee pain, an axial view should be included in the initial radiographic study. An MRI examination for nontraumatic knee pain is indicated when the pain is persistent and conventional radiographs are nondiagnostic or for which additional information is necessary before instituting treatment or surgical intervention. An MRI is not indicated before a physical examination or before routine conventional radiographs or when there is diagnostic conventional radiograph evidence of severe degenerative joint diseases, inflammatory arthritis, stress fracture, osteonecrosis, or reflex sympathetic dystrophy, for which additional imaging is not going to alter the treatment plan. A nuclear medicine bone scan may be indicated if there is a clinical need to confirm or exclude other sites of involvement (e.g., suspicion of metastatic disease).

Abbreviations

• AP, anteroposterior
• CT, computed tomography
• MRI, magnetic resonance imaging
• NUC, nuclear medicine
• US, ultrasound

Algorithms were not developed from criteria guidelines.

The recommendations are based on analysis of the current literature and expert panel consensus.

• Pavlov H, Dalinka MK, Alazraki NP, Daffner RH, DeSmet AA, El-Khoury GY, KNeeland JB, Manaster BJ, Rubin DA, Steinbach LS, Weissman BN, Haralson RH III, Expert Panel on Musculoskeletal Imaging. Nontraumatic knee pain. [online publication]. Reston (VA): American College of Radiology (ACR); 2005. 9 p. [44 references]

Not applicable: The guideline was not adapted from another source.

1995 (revised 2005)

American College of Radiology - Medical Specialty Society

American College of Radiology (ACR) provided the funding and the resources for these ACR Appropriateness Criteria®.

Committee on Appropriateness Criteria; Expert Panel on Musculoskeletal Imaging

Panel Members: Helene Pavlov, MD; Murray K. Dalinka, MD; Naomi P. Alazraki, MD; Richard H. Daffner, MD; Arthur A. DeSmet, MD; George Y. El-Khoury, MD; John B. Kneeland, MD; B.J. Manaster, MD, PhD; David A. Rubin, MD; Lynne S. Steinbach, MD; Barbara N. Weissman, MD; Robert H. Haralson III, MD

Not stated

This is the current release of the guideline.

This guideline updates a previous version: Pavlov H, Dalinka MK, Alazraki N, Berquist TH, Daffner RH, DeSmet AA, el-Khoury GY, Goergen TG, Keats TE, Manaster BJ, Newberg A, Haralson RH, McCabe JB, Sartoris D. Nontraumatic knee pain. American College of Radiology. ACR Appropriateness Criteria. Radiology 2000 Jun;215(Suppl):311-20.

The appropriateness criteria are reviewed annually and updated by the panels as needed, depending on introduction of new and highly significant scientific evidence.

None available

This summary was completed by ECRI on May 6, 2001. The information was verified by the guideline developer as of June 29, 2001. This NGC summary was updated by ECRI on January 30, 2006.