Patella Rad 101 2024 PDF

Patella RAD 101 Chapter 6 References: Bontrager & Textbook of Radiographic Positioning and Related Anatomy  Identify the following parts and prominences Identify on an image or skeleton: Patella (Base, Apex) Learning Desc...

Patella RAD 101 Chapter 6 References: Bontrager & Textbook of Radiographic Positioning and Related Anatomy  Identify the following parts and prominences Identify on an image or skeleton: Patella (Base, Apex) Learning Describe the routine & special projections for Describe the: Objectives Patella Discuss Discuss why each projection may be requested Patella Anatomy Flat triangular Approximately 2in in diameter bone Apex Inferior border Base Superior Border Outer/Anterior Rough & Convex surface What type of bone Inner/Posterior Smooth & oval shaped surface Articulates with femur is the Patella? Patella Anatomy Protects the anterior aspect of the knee joint Job? Increase the leverage of the quadriceps femoris muscle Leg Extended: Patella is loose & movable Sits more superior Movement Leg flexed: Patella locks into position Sits more distally Patella Projections PA Lateral Tangential Merchant, Inferosuperior, Hughston, Settegast, and Hobbs PA – Patella Clinical Indications: Evaluation of patellar fractures before knee joint is flexed for other projections Patient prone, leg fully extended True PA, typically requires 5- degree internal rotation CR perpendicular, directed to midpatella, about midpopliteal crease Lateral (Mediolateral) - Patella Clinical Indications: Evaluation of patellar fractures in conjunction with the PA Abnormalities of the patellofemoral and femorotibial joints Place patient in lateral recumbent position, affected side down Flex knee only 5-10˚ CR perpendicular, directed at mid-patellofemoral joint Tangential – Axial or Sunrise/Skyline Projection Clinical Indications: Subluxation of patella and other abnormalities of the patella & patellofemoral joint  Merchant Bilateral Method No Grid Air Gap * SID 48-72 inches Patient supine with knees flexed 40˚ over the end of the table, resting on leg support. Place IR against legs approximately inches below the knees, perpendicular to x-ray beam CR Angled 30˚ caudad, from horizontal plane* CR directed to point midway between patellae Evaluation Criteria (Tangential Patella—Merchant Method) Intercondylar sulcus and patella visualized Femoropatellar joint spaces open Optimal exposure factors  Inferosuperior - Patella SID 40-48 Nongrid Place patient in supine position, legs together, with sufficient-sized support placed under knees for 40-45˚ knee flexion (legs relaxed) Place IR Resting on midthighs, tilted to be perpendicular to CR CR Directed inferosuperiorly at 10-15˚ from lower legs (start at horizontal) to be tangential to patellofemoral joint  Settegast Method - Patella Place patient in prone or seated position Flex knee to a minimum of 90˚ Have patient hold onto gauze or tape to maintain position (prone) Direct CR tangential to patellofemoral joint space (15-20˚ from lower leg)(start at horizontal) Minimum of 40in SID Superoinferior Sitting Tangential Method – Patella (Hobbs Modification) Place patient seated in a chair IR under knees resting on a step stool or support (reduce OID) Knees should be flexed with feet placed slightly underneath the chair CR to be perpendicular to IR (tangential to patellofemoral joint) Direct CR to mid-patellofemoral joint SID 48-50 inches Hobbs Modification