The guidelines created by the New York State workers compensation board aim to support physicians, and healthcare professionals in offering suitable treatment for Knee Injury
Healthcare professionals can rely on these Workers Compensation Board guidelines to make informed decisions about the optimal care for individuals dealing with Knee Injury
It’s important to note that these guidelines do not replace clinical judgement or professional expertise. The patient, in collaboration with their healthcare provider, is responsible for making the final decision regarding their care.
Diagnostic Imaging Studies: General Principles
As detailed in the General Principles, the choice of diagnostic imaging studies is contingent upon the specific clinical presentation and clinical judgment. There may be instances where repeat or alternative diagnostic imaging is clinically necessary.
Such instances include, but are not limited to, situations where a prior test is of poor quality and/or nondiagnostic, the clinical situation changes (e.g., new or worsening symptoms, preparing for surgery or therapeutic injections, etc.), or monitoring clinical progress (e.g., post-operatively) or deterioration over time is required.
Making prudent choices in procedure(s) or a proper sequential order in multiple procedures ensures maximum diagnostic accuracy, minimizes adverse effects on patients, and promotes clinical efficiency.
Repeating procedures increases cumulative radiation dose and associated risks. Diagnostic imaging procedures exhibit varying degrees of sensitivity and specificity for any diagnosis. The selection and interpretation of imaging studies should be based on clinical history, physical examination, and clinical judgment.
Choice of Imaging Procedures
While plain X-rays are generally a useful starting point, they may not always suffice. Magnetic resonance imaging (MRI), arthrography, or computed axial tomography (CT) scanning following arthrography can provide valuable information for various knee disorders.
In specific circumstances, as mentioned earlier, repeat or alternative imaging may be justified. The selection of one procedure over others usually depends on multiple factors. When necessary, additional imaging studies for further evaluation of the lower extremity can be employed based on the mechanism of injury, symptoms, and patient history. The following studies are listed in order of frequency of use, not importance.
Magnetic Resonance Imaging (MRI)
Recommended – in select patients.
Indications: Magnetic Resonance Imaging (MRI) offers a more definitive visualization of soft tissue structures, including ligaments, tendons, joint capsule, menisci, and joint cartilage structures, compared to x-ray or Computed Axial Tomography, particularly in the assessment of traumatic or degenerative injuries. The use of intravenous or intra-articular contrast can enhance the definition of selected pathologies.
Generally, high-field conventional MRI provides superior resolution than that of a lower-field scan (open-field MRI). A lower-field scan may be warranted when a patient cannot fit into a high-field scanner or experiences excessive claustrophobia even with sedation. If the resolution is inadequate in the first scan, a second MRI using a different technique may be necessary.
A subsequent diagnostic MRI may involve repeating the same procedure if the rehabilitation physician, radiologist, or surgeon deems the initial study’s quality insufficient for a diagnosis. Any inquiries regarding this matter should be addressed with the MRI center and/or radiologist. The presence of ferrous material/metallic objects in the tissues is a contraindication for performing an MRI.
Computed Tomography (CT)
Recommended – in select patients.
Indications: Computed Axial Tomography (CT) provides excellent visualization of bone and is utilized for further assessment of bony masses and suspected fractures not clearly identified on radiographic window evaluation. Instrument scatter-reduction software enhances resolution when metallic artifact is a concern. When ferrous/metallic materials are present in the tissues, CT should be ordered instead of MRI. CT examinations involve exposure to ionizing radiation, with associated radiation-related risks.
Lineal Tomography
Not Recommended
Bone Scan (Radioisotope Bone Scanning)
Recommended – in select patients.
Indications: 99MTechnecium diphosphonate uptake reflects osteoblastic activity and may be beneficial in trauma, metastatic or primary bone tumors, stress fractures, occult fractures, osteomyelitis, and inflammatory lesions. However, it cannot distinguish among these entities.
Other Radionuclide Scanning
Recommended – in select patients.
Indications: Indium and gallium scans are typically used to assist in diagnosing lesions observed in other diagnostic imaging studies. 67Gallium citrate scans aid in localizing tumors, infections, and abscesses. 111Indium-labeled leukocyte scanning is employed to localize infection or inflammation.
Arthrograms
Recommended – in select patients
Indications: Arthrograms may be valuable in assessing internal derangement of a joint, only when MRI or other tests are contraindicated, not deemed diagnostic, or unavailable. This testing may be appropriate in select patients where the clinical benefits outweigh the risks, and when MRI is either non-diagnostic, not clinically indicated, or clinically contraindicated. Note: Potential complications of this more invasive technique include pain, infection, and allergic reactions.
Other Tests
The studies below are listed by frequency of use, not importance.
Electromyography (EMG) and Nerve Conduction Velocity Studies (NCV)
Recommended – in select patients.
Indications: Electrodiagnostic studies have limited use in knee disorders. It is recommended and preferable that EDX in the outpatient setting be conducted and interpreted by physicians board-certified in Neurology or Physical Medicine and Rehabilitation.
Somatosensory Evoked Potentials (SSEP)
Not Recommended
Doppler Ultrasonography/Plethysmography
Recommended – in select patients.
Indications: Doppler Ultrasonography/Plethysmography is valuable in diagnosing arterial and venous disease in the lower extremity and should be considered before more invasive venogram or arteriogram studies.
Doppler is less sensitive in detecting deep-vein thrombosis in the calf muscle area. If the test is initially negative, an ultrasound should be repeated 7 days post-initial symptoms to rule out popliteal thrombosis. It is also useful for diagnosing a popliteal mass when MRI is unavailable or contraindicated. Note: A Doppler study is useful in investigating the popliteal space for masses. Some physicians may use ultrasound to guide diagnostic procedures and aspirations of loculated fluid collections.
Venogram/Arteriogram
Recommended – in select patients.
Indications: Venogram/Arteriogram is beneficial for investigating vascular injuries or diseases, including deep-venous thrombosis. Potential complications may include pain, allergic reactions, and deep-vein thrombosis.
