Reading assignment: Lower Leg

Anatomy: lower leg, knee, & Merrils, Vol. 1: Chapter 6 Film Critique #3 patella Lab demonstration Positioning: lower leg

Positioning: knee Reading assignment: Knee

Merrils, Vol. 1: Chapter 6 Film Critique #4

& Lab demonstration

Positioning: intercondylar fossa Reading assignment: Intercondylar fossa and patella & patella Merrils, Vol. 1: Chapter 6 Lab demonstration

Anatomy: Femur Reading assignment: Femur

Positioning: Femur Merrils, Vol. 1: Chapters 6 & 7 Film Critique #5

Lab demonstration

Leg……

The leg is composed of two long bones:

 Tibia – medial bone; second largest bone in the body  Fibula – lateral bone

The tibia has several anatomical features of note. See whether you can locate each on the diagram.

Proximal end:

 Medial condyle  Lateral condyle  Tibial plateaus  Intercondylar eminence  Tibial tuberosity Body – features anterior crest

Distal end:

 Medial malleolus  Fibular notch

The head of the fibula is located at its proximal end and has a pointed apex laterally. Distally, the fibular features the lateral malleolus.

The articulations between the two leg bones are discussed on Screen 1.13.

Knee…..

The knee joint is the articulation between the femoral condyles and the tibial plateaus. Numerous soft tissues support and reinforce the knee, including the:

 Menisci  Cruciate ligaments  Collateral ligaments

These supporting soft tissue structures are enclosed in a common joint capsule.

The knee joint is of the hinge type, capable of flexion and extension only. The anterior knee joint is protected by the patella and patellofemoral joint.

The patella is the largest and most constant sesamoid bone. It develops in the quadriceps femoris tendon between the ages of 3 and 5 years. The anterior distal surface of the femur has a shallow triangular depression, the patellar surface between the two condyles for articulation with the patella. This articulation is termed the patellofemoral joint. This synovial gliding joint protects the knee joint.

Femur….

1.12 Femur

The femur, the bone of the thigh region of the lower limb, is the longest, strongest bone in the human body. It has several anatomical features of note. Click to enlarge the illustration and see whether you can locate the following landmarks:

 Head  Patellar surface  Neck  Lateral condyle  Greater trochanter  Medial condyle  Lesser trochanter  Intercondylar fossa  Body  Adductor tubercle  Lateral epicondyle  Popliteal surface  Medial epicondyle

Note that some of these features are only seen on either the anterior or posterior view of the femur. It is useful to try describing the location of each anatomical feature as a means of studying and understanding femoral anatomy.

Knee Joint…

Six articulations are formed by the bones of the lower limb. The most distal, the ankle mortise, is discussed on Screen 1.6. The most proximal, the hip joint, will be studied in the next module. The remaining four are:

 Proximal tibiofibular joint o Synovial diarthrosis gliding type  Distal tibiofibular joint o Fibrous syndemosis  Knee joint o Articulation between the femoral condyles and the tibial plateaus o Synovial diarthrosis hinge type  Patellofemoral joint o Patella and patellar surface of anterior, distal femur o Synovial diarthrosis, gliding type

Positioning Steps Results/Rationale Patient is seated with leg extended and affected posterior Provides AP projection surface resting on IR or supine with leg and foot in Maximizes patient comfort and cooperation position described above. IR is centered to lower leg. Centers anatomy of interest to IR Lower limb is in anatomic position. Provides true AP of tibia and fibula Tibial condyles are parallel to IR. Foot is dorsiflexed to right angle. Demonstrates ankle joint without Plantar surface is perpendicular to IR. superimposition of calcaneus Perpendicular CR enters center of lower leg. Places lower leg and both joints in center of IR and collimated field Longer limbs may require two exposures to image entire limb and adjacent joints. Collimate to 1 inch (2.5 cm) on the sides and 11⁄2 inches Demonstrates all anatomy of interest (4 cm) beyond the ankle and knee joints. Provides radiation protection Improves image quality Provide gonadal shielding. Provides radiation protection/fulfills ethical responsibility Instruct patient to hold still in position for exposure. Reduces possibility of motion

Lateral Projection: Tibia and Fibula

Positioning Steps Results/Rationale Patient is seated with leg extended. Provides mediolateral projection Lateral side of affected limb rests on IR or patient is Maximizes patient comfort and cooperation supine with leg and foot in position described above. IR is centered to lower leg. Centers anatomy of interest to IR Tibial condyles are perpendicular to IR. Provides true lateral of tibia and fibula Malleoli are superimposed and perpendicular to IR. Foot is dorsiflexed to right angle. Demonstrates ankle joint without superimposition of calcaneus Perpendicular CR enters center of lower leg. Places lower leg and both joints in center of IR and collimated field Longer limbs may require two exposures to image entire limb and adjacent joints. Collimate to 1 inch (2.5 cm) on the sides and 11⁄2 Demonstrates all anatomy of interest inches (4 cm) beyond the ankle and knee joints. Provides radiation protection Improves image quality Provide gonadal shielding. Provides radiation protection/fulfills ethical responsibility Instruct patient to hold still in position for exposure. Reduces possibility of motion

Chapter 6, Essential 1. What degenerative conditions Projections of the of the knee are best Knee, pp. 286-297, demonstrated with weight- 300-302, and 304-305 bearing projections? 2. How does patient size affect knee radiography?

Chapter 6, Essential 1. How many variations are there Projections of the for the PA axial—Holmblad Intercondylar Fossa projection for intercondylar Projections, pp. 306- fossa? 309 2. How is the degree of central ray angulation determined for the Camp-Coventry method?

Chapter 6, Essential 1. What amount of knee flexion Patella and is optimal in demonstrating Patellofemoral Joint the patella in a lateral Projections, pp. 311- position? 312 and 316-317 2. What is the relationship between flexion of the knee and the appearance of the patellofemoral joint space? 3. What is the primary disadvantage of the tangential (Settegast method) in demonstrating the patellofemoral joint space?

Chapter 6, Essential 1. How is the angle of the Projections of the femoral body affected by the Femur, pp. 318-321 width of the pelvis?

AP Projection: Knee

Positioning Steps Results/Rationale Patient is seated or supine, with leg extended. Provides AP projection Maximizes patient comfort and cooperation Table bucky is centered to knee joint. Centers anatomy of interest to IR (Located ½ inch [1.3 cm] below patellar apex.) Reduces distortion Lower limb is in anatomic position. Provides true AP of knee joint Tibial condyles are parallel to IR. CR is directed to a point ½ inch (1.3 cm) inferior to the patellar Aligns CR to open knee joint apex. Angle varies, depending on the measurement between the anterior superior iliac spine (ASIS) and the tabletop, as follows:

 <19 cm = 3 to 5 degrees caudad (thin pelvis)  19 to 24 cm = 0 degrees  >24 cm = 3 to 5 degrees cephalad (large pelvis)

Collimate to 10 x 12 inches (25 x 30 cm) field size. Demonstrates all anatomy of interest Provides radiation protection Improves image quality Provide gonadal shielding. Provides radiation protection/fulfills ethical responsibility Instruct patient to hold still in position for exposure. Reduces possibility of motion Close Window Lateral Projection: Knee

Positioning Steps Results/Rationale Patient is recumbent, turned on Provides mediolateral projection affected side with lateral surface of Maximizes patient comfort and cooperation knee on table. Removes opposite limb from anatomy of interest Knee is abducted, with unaffected limb behind. Table bucky is centered to knee Centers anatomy of interest to IR joint. Knee is in lateral position with tibial Provides true lateral position of knee joint condyles perpendicular to IR. Degree of flexion relaxes muscles to demonstrate maximum Knee is flexed 20 to 30 degrees. volume of joint cavity CR angle is 5 to 7 degrees Aligns CR to open knee joint cephalad. Slight angle on the CR prevents the joint space from being Enters knee joint 1 inch (2.5 cm) obscured by the magnified image of the medial femoral condyle. distal to the medial epicondyle. Collimate to 10 x 12-inch (25 x 30- Demonstrates all anatomy of interest cm) field size. Provides radiation protection Improves image quality Provide gonadal shielding. Provides radiation protection/fulfills ethical responsibility Instruct patient to hold still in Reduces possibility of motion position for exposure. Close Window

AP Projection: Knees, Standing

Positioning Steps Results/Rationale Patient stands upright, back against vertical grid device. Provides AP weight-bearing projection Vertical grid device is centered to knee joints (located ½ Centers anatomy of interest to IR inch [1.3 cm] below patellar apex). Reduces distortion Weight is equally distributed on both feet, which are facing Provides weight bearing to demonstrate forward. joint narrowing Reduces risk of rotation or distortion Horizontal CR is directed perpendicular and enters ½ inch Centers knees to collimated field (1.3 cm) inferior to the patellar apices. Collimate to a 14 x 17-inch (35 x 43-cm) field size. Demonstrates all anatomy of interest Provides radiation protection Improves image quality Provide gonadal shielding. Provides radiation protection/fulfills ethical responsibility Instruct patient to hold still in position for exposure. Reduces possibility of motion

AP Oblique Projection: Knee, Lateral Rotation

Positioning Steps Results/Rationale Patient seated or supine with leg extended Provides AP oblique projection Maximizes patient comfort and cooperation Table bucky is centered to knee joint (located ½ inch [1.3 Centers anatomy of interest to IR & cm] below patellar apex). reduces distortion Lower limb is rotated laterally 45 degrees; elevate and Provides oblique position of knee joint support unaffected limb, if necessary. CR is directed to a point ½ inch (1.3 cm) inferior to the Aligns CR to open knee joint patellar apex. Angle varies, depending on the measurement between the ASIS and the tabletop:

 <19 cm = 3 to 5 degrees caudad (thin pelvis)  19 to 24 cm = 0 degrees  >24 cm = 3 to 5 degrees cephalad (large pelvis)

Collimate to 10 x 12-inch (25 x 30-cm) field size. Demonstrates all anatomy of interest Provides radiation protection Improves image quality Provide gonadal shielding. Provides radiation protection/fulfills ethical responsibility Instruct patient to hold still in position for exposure. Reduces possibility of motion.

AP Oblique Projection: Knee, Medial Rotation

Positioning Steps Results/Rationale Patient is seated or supine with leg extended. Provides AP oblique projection Maximizes patient comfort and cooperation Table bucky is centered to knee joint (located ½ inch [1.3 Centers anatomy of interest to IR & cm] below patellar apex). reduces distortion Lower limb is rotated medially 45 degrees; elevate and Provides oblique position of knee joint support affected limb, if necessary. Opens proximal tibiofibular joint CR is directed to a point ½ inch (1.3 cm) inferior to the Aligns CR to open knee joint patellar apex. Angle varies, depending on the measurement between the ASIS and the tabletop:

 <19 cm = 3 to 5 degrees caudad (thin pelvis)  19 to 24 cm = 0 degrees  >24 cm = 3 to 5 degrees cephalad (large pelvis)

Collimate to 10 x 12-inch (25 x 30-cm) field size. Demonstrates all anatomy of interest Provides radiation protection Improves image quality Provide gonadal shielding. Provides radiation protection/fulfills ethical responsibility Instruct patient to hold still in position for exposure. Reduces possibility of motion Close Window

PA Axial Projection: Intercondylar Fossa (Holmblad Method)

Positioning Steps Results/Rationale Patient may be examined in one of three positions: Consideration of patient safety in choice of position 1. Standing: Knee of interest is flexed and resting on a Provides PA axial projection stool at the side of the table. 2. Standing at tableside: Affected knee is flexed and placed in contact with the front of the IR. 3. Kneeling on the table (original Holmblad method): Affected knee is over the IR (pictured above).

Center IR to patella. Centers anatomy of interest to IR and reduces distortion Flex knee 70 degrees from full extension. Opens intercondylar fossa CR is perpendicular to the lower leg and centered to IR. Centers open intercondylar fossa to collimated field Collimate to a 8 x 10-inch (18 x 24 cm) field size. Demonstrates all anatomy of interest Provides radiation protection Improves image quality Provide gonadal shielding. Provides radiation protection/fulfills ethical responsibility Instruct patient to hold still in position for exposure. Reduces possibility of motion

PA Axial Projection: Intercondylar Fossa (Camp-Coventry Method)

Positioning Steps Results/Rationale Patient is prone on table. Provides PA axial projection Place tibial condyles parallel to IR. Reduces distortion Flex knee to 40- or 50-degree angle. Opens intercondylar fossa Provide proper support for lower leg and foot. Reduces risk of motion CR is perpendicular to the lower leg and centered to Centers open intercondylar fossa to collimated IR: field

 Angled 40 degrees when knee is flexed 40 degrees  Angled 50 degrees when knee is flexed 50 degrees

Collimate to a 8 x 10-inch (18 x 24 cm) field size. Demonstrates all anatomy of interest Provides radiation protection Improves image quality Provide gonadal shielding. Provides radiation protection/fulfills ethical responsibility Instruct patient to hold still in position for exposure. Reduces possibility of motion

PA Projection: Patella

Positioning Steps Results/Rationale Patient lies prone on table. Provides PA projection Place patella parallel to IR (usually requires heel to be Reduces distortion rotated 5 to 10 degrees laterally). CR is perpendicular to midpopliteal area. Centers patella to collimated field Collimate to a 6 x 6-inch (15 x 15-cm) field size. Demonstrates all anatomy of interest Provides radiation protection Improves image quality Provide gonadal shielding. Provides radiation protection/fulfills ethical responsibility Instruct patient to hold still in position for exposure. Reduces possibility of motion

Lateral Projection: Patella

Positioning Steps Results/Rationale Patient lies in lateral recumbent position. Provides mediolateral projection Lateral surface of affected knee rests on table. Unaffected leg is placed in front, resting on table for support. Flex knee 5 to 10 degrees, with femoral epicondyles Opens patellofemoral joint space (too much superimposed. flexion decreases joint space) Place patella perpendicular to IR. Places patella in lateral position CR is perpendicular to IR; enters the knee at the Centers patella to collimated field midpatellofemoral joint. Collimate to a 4 x 4-inch (10 x 10-cm) field size. Demonstrates all anatomy of interest Provides radiation protection Improves image quality Provide gonadal shielding. Provides radiation protection/fulfills ethical responsibility Instruct patient to hold still in position for exposure. Reduces possibility of motion Tangential Patella and Patellofemoral Joint (Settegast Method)

Positioning Steps Results/Rationale Patient lies prone (preferred) or sits with knee Do not flex knee until a transverse fracture flexed. of the patella has been ruled out with a lateral image. Patient comfort considered in choice of position Provides tangential projection Flex knee slowly until patella is perpendicular to IR if Positions patella and patellofemoral joint space patient's condition permits. for tangential projection CR is perpendicular to patella and IR when patella is Centers patella and patellofemoral joint to perpendicular. collimated field If not, angle CR into joint space, typically 15 to 20 Opens joint space degrees. CR enters the knee at the patellofemoral joint. Collimate to 4 x 4-inch (10 x 10-cm) field size for Demonstrates all anatomy of interest unilateral image; 4 x 10-inch (10 x 25-cm) field is Provides radiation protection required for bilateral image. Improves image quality Provide gonadal shielding. Provides radiation protection/fulfills ethical responsibility Instruct patient to hold still in position for exposure. Reduces possibility of motion

AP Projection: Femur, Proximal Portion Positioning Steps Results/Rationale Patient is supine, with no rotation of pelvis. Provides AP projection Internally rotate limb 10 to 15 degrees. Positions femoral neck in profile Top of IR (if used) is placed at level of ASIS. Includes entire hip joint and proximal femur CR is perpendicular to midfemur and IR center. Centers proximal femur to collimated field Collimate to 1 inch (2.5 cm) beyond medial and lateral skin Demonstrates all anatomy of interest shadows of thigh and 17 inches (43 cm) long. Provides radiation protection Improves image quality Provide gonadal shielding. Provides radiation protection/fulfills ethical responsibility Instruct patient to hold still in position for exposure. Reduces possibility of motion

AP Projection: Femur, Distal Portion

Positioning Steps Results/Rationale Patient is supine, with no rotation of pelvis. Provides AP projection Position femoral and tibial condyles parallel. Positions femur in anatomic position Bottom of IR (if used) is placed 2 inches distal to knee joint. Includes entire knee joint and distal femur CR is perpendicular to midfemur and IR center. Centers distal femur to collimated field Collimate to 1 inch beyond medial and lateral skin shadows Demonstrates all anatomy of interest of thigh and 17 inches (43 cm) long. Provides radiation protection Improves image quality Provide gonadal shielding. Provides radiation protection/fulfills ethical responsibility Instruct patient to hold still in position for exposure. Reduces possibility of motion

Lateral Projection: Femur, Proximal Portion

Positioning Steps Results/Rationale Patient lies in lateral recumbent on affected side, with Provides mediolateral projection unaffected limb placed behind affected limb for support. Optimizes patient comfort Rotate unaffected side of pelvis posteriorly 10 to 15 Positions femoral neck in lateral without degrees to prevent superimposition of hip of interest. superimposition of unaffected side Top of IR (if used) is placed at level of ASIS. Includes entire hip joint and proximal femur CR is perpendicular to midfemur and IR center. Centers proximal femur to collimated field Collimate to 1 inch beyond skin shadows of thigh and 17 Demonstrates all anatomy of interest inches (43 cm) long. Provides radiation protection Improves image quality Provide gonadal shielding. Provides radiation protection/fulfills ethical responsibility Instruct patient to hold still in position for exposure. Reduces possibility of motion

Lateral Projection: Femur, Distal Portion

Positioning Steps Results/Rationale Patient lies in recumbent lateral, resting on affected side, Provides mediolateral projection with pelvis in lateral position. Optimizes patient comfort Position unaffected limb in front of affected limb for support. Femoral and tibial condyles are perpendicular. Positions distal femur in lateral position Flex knee about 45 degrees. Bottom of IR (if used) is placed 2 inches distal to knee Includes entire knee joint and distal femur joint. CR is perpendicular to midfemur and IR center. Centers distal femur to collimated field Collimate to 1 inch beyond skin shadows of thigh and 17 Demonstrates all anatomy of interest inches (43 cm) long. Provides radiation protection Improves image quality Provide gonadal shielding. Provides radiation protection/fulfills ethical responsibility Instruct patient to hold still in position for exposure. Reduces possibility of motion  Module Outline  Glossary  Media

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Section 3: Lower Limb Image Evaluation

3.1 Reading Assignment: Lower Limb Image Evaluation

Image evaluation is a foundational skill for radiographers. Each projection has specific criteria that allow the radiographer to evaluate the image for evidence of proper positioning, as well as adequate image quality. A criterion common to all chest images are:

 Visibility of legal identification and appropriate side marker

This criterion means that the institution and required patient information be a permanent part of the image, and that the correct side marker is visible, noting the right or left side of the patient.

Take time now to study the bulleted points under the heading "Evaluation Criteria" for each essential projection specified in the table below.

Readings from Merrill's Atlas of Radiographic Positioning & Procedures, vol. 1, 12th edition.

Chapter 6, Essential Projections: 1. What is the appropriate size of the collimated Toes - Ankle, pp. 242-243, 245- field? 249, 252-257, 260-261, 271, 274, 2. What anatomy is demonstrated in each 279-281, 283-285 and 287 projection? 3. How does the anatomy of interest appear on images when positioning is correct? Chapter 6, Essential Projections: Leg - Knee, pp. 290-293, 296-297, 300-302, and 304-309,

Chapter 6, Essential Projections: Patella - Femur, pp. 311-312, 316- 321

AP leg

Major critique criteria

 Ankle and knee joints on one or more AP projections  Ankle and knee joints without rotation  Proximal and distal articulations of the tibia and fibula moderately overlapped  Fibular midshaft free of tibial superimposition  Proper density and contrast evidenced by: o Trabecular detail and soft tissue for the entire leg

The arrows in this image demonstrate the importance of including both the proximal and distal articulations on radiographic examinations of long bones. The distal tibia is fractured, as is the proximal fibula. Fractures at opposite ends are not uncommon.

Lateral leg

Major critique criteria

 Ankle and knee joints on one or more images  Distal fibula lying over the posterior half of the tibia  Slight overlap of the tibia on the proximal fibular head  Ankle and knee joints not rotated  Possibly no superimposition of femoral condyles because of divergence of the beam  Moderate separation of the tibial and fibular bodies or shafts (except at their articular ends)  Proper density and contrast, as evidenced by: o Trabecular detail and soft tissue

AP knee

Major critique criteria

 Open femorotibial joint space, with interspaces of equal width on both sides if the knee is normal  Knee fully extended if patient's condition permits  Patella completely superimposed on the femur  No rotation of the femur (femoral condyles symmetrical) and tibia (intercondylar eminence centered)  Slight superimposition of the fibular head if the tibia is normal  Soft tissue around the knee joint  Bony detail surrounding the patella on the distal femur

Lateral knee

Major critique criteria

Femoral condyles superimposed  o Locate the adductor tubercle on the posterior surface of the medial condyle to identify the medial condyle and to determine whether the knee is overrotated or underrotated.

 Open joint space between femoral condyles and tibia  Patella in a lateral profile  Open patellofemoral joint space  Fibular head and tibia slightly superimposed o Overrotation causes less superimposition, and underrotation causes more superimposition.  Knee flexed 20 to 30 degrees  All soft tissue around the knee  Femoral condyles with proper density

AP knees, standing

Major critique criteria

 No rotation of the knees  Both knees

 Knee joint space centered to the exposure area  Adequate IR size to demonstrate the longitudinal axis of the femoral and tibial bodies or shafts

AP oblique knee, lateral rotation

Major critique criteria

 Medial femoral and tibial condyles  Tibial plateaus  Open knee joint  Fibula superimposed over the lateral half of the tibia

 Margin of the patella projected slightly beyond the edge of the lateral femoral condyle  Soft tissue around the knee joint  Bony detail on the distal femur and proximal tibia

AP oblique knee, medial rotation

Major critique criteria

 Open proximal tibiofibular articulation  Posterior tibia  Lateral condyles of the femur and tibia  Both tibial plateaus  Open knee joint  Margin of the patella projecting slightly beyond the medial side of the femoral condyle  Soft tissue around the knee joint  Bony detail on the distal femur and proximal tibia PA axial intercondylar fossa (Holmblad)

Major critique criteria

 Open fossa  Posteroinferior surface of the femoral condyles  Intercondylar eminence and knee joint space

 Apex of the patella not superimposing the fossa  No rotation, evident by slight tibiofibular overlap  Soft tissue in the fossa and interspaces  Bony detail on the intercondylar eminence, distal femur, and proximal tibia

PA axial intercondylar fossa (Camp-Coventry)

Major critique criteria

 Open fossa  Posteroinferior surface of the femoral condyles  Intercondylar eminence centered in open femorotibial joint space

 Apex of the patella not superimposed on the fossa  No rotation, as evidenced by slight tibiofibular overlap  Soft tissue in the fossa and interspaces  Bony detail on the intercondylar eminence, distal femur, and proximal tibia

PA patella

Major critique criteria

 Patella subject to complete superimposition by the femur  Adequate penetration for visualization of the patella clearly through the superimposed femur  No rotation

The arrow points to a fracture line in the patella.

Lateral patella

Major critique criteria

 Knee flexed 5 to 10 degrees

 Open patellofemoral joint space  Patella in lateral profile

 Close collimation

Tangential patella and patellofemoral joint (Settegast)

Major critique criteria

 Patella in profile  Open patellofemoral articulation  Surfaces of the femoral condyles  Soft tissue of the patellofemoral articulation  Bony detail on the patella and femoral condyles

AP proximal femur

Major critique criteria

 Majority of the femur and the joint nearest the pathologic condition or site of injury o A second

projection of the other joint is recommended  Femoral neck not foreshortened on the proximal femur  Lesser trochanter not seen beyond the medial border of the femur, or only a very small portion seen on the proximal femur  Gonad shielding when indicated, but the shield not covering proximal femur  Any orthopedic appliance in its entirety  Trabecular recorded detail on the femoral shaft

AP distal femur

Major critique criteria

 Majority of the femur and the joint nearest the pathologic condition or site of injury

o A second projection of the other joint is recommended.  No knee rotation of the distal femur  Gonad shielding when indicated, but the shield not covering proximal femur  Any orthopedic appliance in its entirety  Trabecular recorded detail on the femoral shaft

Lateral proximal femur

Major critique criteria

 Majority of the femur and the joint nearest the pathologic condition or site of injury o A second

radiograph of the other end of the femur is

recommended  Opposite thigh not over area of interest  Greater and lesser trochanters not prominent  Any orthopedic appliance in its entirety  Trabecular detail on the femoral body Lateral distal femur

Major critique criteria

 Majority of the femur and the joint nearest the pathologic condition or site of injury o A second

radiograph of the other end of the femur is recommended  Superimposed anterior surface of the femoral condyles  Patella in profile  Open patellofemoral space  Inferior surface of the femoral condyles not superimposed because of divergent rays  Any orthopedic appliance in its entirety  Trabecular detail on the femoral body

AP Oblique Projection: Leg in Medial Rotation

Positioning Steps Results/Rationale Patient is seated or lying supine with leg extended. Provides AP oblique projection Posterior surface rests on IR (if used). Rotate lower limb medially 45 degrees. Demonstrates tibia and fibula in medial (internal) oblique position Demonstrates the maximum interosseous space between the tibia and fibula CR is perpendicular to center of IR. Centers tibia and fibula and adjacent joints on IR and collimated field Collimate 1-inch (2.5-cm) border around shadow of skin on all Demonstrates all anatomy of sides interest Provides radiation protection Improves image quality Provide gonadal shielding. Provides radiation protection/fulfills ethical responsibility Instruct patient to hold position for exposure. Reduces possibility of motion

AP Oblique Projection: Leg in Lateral Rotation

Positioning Steps Results/Rationale Patient is seated or supine, leg extended. Provides AP oblique projection Posterior surface rests on IR (if used). Rotate lower limb laterally 45° Demonstrates tibia and fibula in lateral (external) oblique position Demonstrates fibula superimposed by tibia CR is perpendicular to center of IR. Centers tibia and fibula and adjacent joints on IR and collimated field Collimate 1-inch (2.5-cm) border around shadow of skin on all Demonstrates all anatomy of sides. interest Provides radiation protection Improves image quality Provide gonadal shielding. Provides radiation protection/fulfills lethical responsibility Instruct patient to hold position for exposure. Reduces possibility of motion AP oblique leg, medial rotation

Major critique criteria

 Proximal and distal tibiofibular articulations

included  Maximum interosseous space between the tibia and fibula  Ankle and knee joints demonstrated o May require separate images on longer limbs

AP oblique leg, lateral rotation

Major critique criteria

 Fibula superimposed by lateral portion of tibia  Ankle and knee joints included o May require two images on longer limbs

PA Projection: Knee

Positioning Steps Results/Rationale Patient lies prone with leg extended and toes resting on table. Provides PA projection Femoral condyles are placed parallel to tabletop. Demonstrates knee joint without rotation CR is directed at an angle of 5 to 7 degrees caudad to exit at a Centers knee joint to collimated field point ½ inch (1.3 cm) inferior to the patellar apex. Collimate a 1-inch (2.5-cm) border around shadow of skin on Demonstrates all anatomy of interest all sides. Provides radiation protection Improves image quality Provide gonadal shielding. Provides radiation protection/fulfills ethical responsibility Instruct patient to hold position for exposure. Reduces possibility of motion

PA Projection: Knees (Rosenthal Method)

Positioning Steps Results/Rationale Patient stands facing vertical grid device, weight equally Provides PA projection distributed on both feet. Flex the knees to place the femurs at an angle of 45 degrees. Demonstrates knee joint without Patient may grasp sides of grid device for support. rotation Used to evaluate joint space narrowing and articular cartilage disease Center IR to knee joints (½ in. or 1.3 cm inferior to patellar Demonstrates knee joint in center of apices). image and collimated field CR is horizontal and perpendicular to the center of the IR; Demonstrates open knee joints in enters perpendicular to the tibia and fibula, but a 10-degree weight-bearing position caudal angle is sometimes used. Collimate 1-inch (2.5-cm) border around shadow of skin on all Demonstrates all anatomy of interest sides. Provides radiation protection Improves image quality Provide gonadal shielding. Provides radiation protection/fulfills ethical responsibility Instruct patient to hold position for exposure. Reduces possibility of motion

AP Axial Projection: Intercondylar Fossa (Béclère Method)

Positioning Steps Results/Rationale Patient is seated or supine, with no rotation in lower Provides AP projection limbs. Flex the knee enough to place the long axis of the Demonstrates intercondylar fossa femur at a 60-degree angle to long axis of tibia. Support knee with sandbags. Place IR under knee on top of sandbags. Demonstrates intercondylar fossa in center of Center IR to the CR. image and collimated field CR is perpendicular to the lower leg; enters ½ in (1.3 Demonstrates open intercondylar fossa in AP cm) inferior to the patellar apex. axial projection Collimate 1-inch (2.5-cm) border around shadow of Demonstrates all anatomy of interest skin on all sides. Provides radiation protection Improves image quality Provide gonadal shielding. Provides radiation protection/fulfills ethical responsibility Instruct patient to hold position for exposure. Reduces possibility of motion

Tangential Projection: Patella and Patellofemoral Joint (Hughston Method)

Positioning Steps Results/Rationale Patient lies prone, without rotation. Reduces distortion IR is under affected knee. Reduces magnification Knee is flexed to place tibia-fibula at 50- to 60- Positions patella to obtain a tangential projection degree angle to table. Support ankle and foot as needed. (To avoid burns, make sure that the collimator is not hot!) Make sure the leg is not rotated medially or Reduces distortion laterally from the vertical. CR is directed 45 degrees cephalad through the Demonstrates tangential projection of patella & joint patellofemoral joint. space in the center of the collimated field Collimate 1-inch (2.5-cm) border around shadow Demonstrates all anatomy of interest of skin on all sides. Provides radiation protection Improves image quality Provide gonadal shielding. Provides radiation protection/fulfills ethical responsibility Instruct patient to hold position for exposure. Reduces possibility of motion

Tangential Projection: Patella and Patellofemoral Joint (Merchant Method)

Positioning Steps Results/Rationale Patient lies supine with knees at end of table. Holds legs and knees in desired position and Support knees, lower legs, and IR in "axial relationship to IR viewer" device. Using axial viewer device, elevate knees about 2 Helps relax quadriceps femora muscles for optimal inches (5 cm) to place femora parallel to table. demonstration of the joint space Knee is flexed 40 degrees. Positions patella to obtain a tangential projection Place IR perpendicular to the CR and IR position aligned to central ray and patellae per approximately 1 foot distal to the patellae Merchant method Rest IR on thin foam pad on the patient's shins. Foam pad increases comfort. CR is directed 45 degrees cephalad through the Demonstrates tangential projection of patella and patellofemoral joint. joint space in the center of the collimated field Collimate 1-inch (2.5-cm) border around shadow Demonstrates all anatomy of interest of skin on all sides. Provides radiation protection Improves image quality Provide gonadal shielding. Provides radiation protection/fulfills ethical responsibility Instruct patient to hold position for exposure. Reduces possibility of motion Bilateral examination may be performed. Facilitates comparison

AP Projection: Lower Limbs

Positioning Steps Results/Rationale Increase source-to-IR distance to 8 feet (244 cm). Required to provide long enough image field Patient stands upright in anatomic position on riser. Insures demonstration of entire lower limb Demonstrates lower limbs and joints in anatomic position Weight is equally distributed on feet. Reduces rotation/distortion CR is perpendicular; enters midway between knees at Centers lower limbs in collimated field level of knee joints. Collimate 1-inch (2.5-cm) border around shadow of Demonstrates all anatomy of interest skin on all sides. Provides radiation protection Improves image quality Provide gonadal shielding. Provides radiation protection/fulfills ethical responsibility Instruct patient to hold position for exposure. Reduces possibility of motion