About The PatellaVision™ X-ray Frame

the x-ray frame for the axial view of the patellathe x-ray frame for the axial view of the patella

The PatellaVision™ X-ray Frame is designed to provide a consistent, reliable, and accurate axial view of the patella. This x-ray is also known as a Merchant patella view. For imaging purposes, the patella (kneecap) is easily assessed from the front (A/P view), side (lateral view) using readily available techniques known to x-ray technicians, orthopedic surgeons, and radiologists. However, taking an axial view is technically difficult because the x-ray cassette must be placed in an awkward position on the patient's leg in order to obtain a properly angled projection. The axial view allows the clinician to discover subtle abnormalities in the tracking of the patella over the trochlear groove of the anterior distal femur. Also, fractures and structural abnormalities are often diagnosed with the axial view. The "sunrise view" is commonly used to image the patella however in this highly flexed knee position, potential tracking misalignments can be easily missed. The axial or Merchant view is taken with 30-40 degrees of knee flexion, which enhances the likelihood of discovering patella tracking problems.

the x-ray frame for the axial view of the patellathe x-ray frame for the axial view of the patella

The PatellaVision™ X-ray Frame allows the x-ray technician to produce the axial view with a consistent, easily reproducible technique as well as assuring the patient's comfort and protection from radiation. The technique involves a hands-free frame holder firmly securing a 14x17 x-ray cassette positioned distal to the patella. Unlike the other commercially available axial view holder, the PatellaVision™ is made of stainless steel, plastic laminate, and rolls easily on a rotating wheel base. The knee flexion angle is pre-set for the technician, allowing for a consistent properly angled view of the patella. The frame platform is wide enough to comfortably allow both knees to rest on the frame for a single x-ray exposure of both knees. Because the x-ray is taken from the head position, there is no radiation exposure to the patient, nor do they have to hold the x-ray cassette in position.
Step-by-step instructions for the x-ray technician can be found here »

Imaging both knees allows for comparison of tracking patterns. Large and small legs will rest safely on the frame platform. The cassette holders are made of stainless steel and are bolted onto the frame. The cassette "arms" also are movable to allow the patient to move their legs easily onto the frame as well as allowing the tech to position the cassette above the anterior surface of the patient's leg.

Patients with acute injuries and post-operative knee surgery patients will find the PatellaVision to be more comfortable. The PatellaVision™ x-ray frame removes many positioning variables in comparison to other axial view techniques, such that the technician can reliably offer the patient a safe and reliable imaging study.