73564

Radiologic examination, knee; complete, 4 or more views

CPT code 73564 represents a complete radiologic examination of the knee encompassing four or more distinct radiographic views. This comprehensive imaging modality is critical in the precise diagnostic evaluation of the complex knee joint structure, which includes the distal femur, proximal tibia, fibula, and the patella. Clinicians typically order this extensive series when a standard two- or three-view examination is insufficient to fully characterize the underlying pathology, such as occult fractures, advanced degenerative joint disease, patellofemoral compartment narrowing, or complex meniscal and ligamentous sequelae that manifest with secondary bony changes. A standard four-view knee protocol conventionally includes an Anteroposterior (AP) view to assess the medial and lateral tibiofemoral joint spaces; a Lateral view to evaluate the patellofemoral joint space and identify any joint effusions or suprapatellar swelling; a Tunnel (or intercondylar notch) view taken with the knee flexed to visualize the intercondylar fossa, tibial spines, and detect intra-articular loose bodies or osteochondritis dissecans; and a Sunrise (or Merchant or skyline) view taken tangentially to evaluate the patellofemoral articulation for subluxation, tilt, or isolated patellofemoral osteoarthritis. Additional oblique views may also be incorporated depending on the specific clinical suspicion, particularly in complex trauma scenarios where subtle tibial plateau fractures or fibular head dislocations are suspected. The procedure is performed by a qualified radiologic technologist who meticulously positions the patient for each specific angle to ensure orthogonal and diagnostic image capture. Shielding is provided according to the ALARA principles to minimize radiation exposure. Upon completion of the multi-view acquisition, a board-certified radiologist reviews the digital radiographs to identify morphological abnormalities, fractures, dislocations, joint space narrowing, osteophyte formation, or lytic or sclerotic bone lesions. Accurate documentation must explicitly state the number and type of views obtained to support the reporting of code 73564 rather than lesser-view codes such as 73560 or 73562.

Clinical Indications

  • Acute trauma to the knee with suspicion of complex fractures involving the tibial plateau, patella, or distal femur.
  • Comprehensive evaluation of advanced osteoarthritis to determine the exact degree of joint space narrowing across all compartments.
  • Patellofemoral pain syndrome, assessing for patellar maltracking, subluxation, or tilt.
  • Detection of intra-articular loose bodies or osteochondritis dissecans using the intercondylar notch view.
  • Preoperative planning for total or partial knee arthroplasty.
  • Postoperative evaluation following hardware placement, ligament reconstruction, or fracture fixation.
  • Unexplained chronic knee swelling, effusion, or mechanical symptoms such as catching and locking.

Procedure Steps

  1. The patient is escorted to the radiography suite and instructed to remove any radiopaque materials from the knee area.
  2. The technologist positions the patient on the X-ray table, ensuring appropriate gonadal shielding is in place.
  3. An Anteroposterior (AP) view is obtained with the patient supine and the leg fully extended.
  4. A Lateral view is captured, typically with the patient in a lateral decubitus position and the knee flexed at approximately 20 to 30 degrees.
  5. A Sunrise or Merchant view is obtained by bending the knee to evaluate the patellofemoral joint space tangentially.
  6. A Tunnel view is taken with the patient kneeling or with the knee flexed 40 to 50 degrees to visualize the intercondylar notch.
  7. Additional views, such as medial or lateral obliques, may be acquired based on the specific clinical order.
  8. The technologist reviews the images for diagnostic quality, ensuring appropriate exposure, contrast, and inclusion of relevant anatomy.
  9. The digital images are transmitted to the Picture Archiving and Communication System (PACS) for radiologist interpretation.
  10. A radiologist dictates a formal report detailing the findings of all views obtained.

Coding Guidelines

  • Report 73564 only when the documentation explicitly confirms four or more views of a single knee were taken.
  • Do not report 73564 in conjunction with 73560 (1 or 2 views) or 73562 (3 views) for the same knee during the same encounter.
  • If the procedure is performed bilaterally, append modifier 50 or the RT/LT modifiers depending on the specific payer requirements.
  • If only the technical component is provided, append modifier TC; if only the professional interpretation is provided, append modifier 26.
  • Views must be distinct and diagnostically useful; simply taking multiple images of the same view does not count toward the view total.
  • Ensure the radiology report lists the specific views taken (e.g., AP, Lateral, Sunrise, Tunnel) to support the code selection.

Associated ICD-10 Codes