Clinical Anatomy, Positioning and Image analysis Flashcards
Movement Type of the Sternoclavicular Joint
Movement Type: Plane or Gliding
Description: Allows limited movement in multiple directions, primarily gliding movements.
Movement Type of the Scapulohumeral Joint
Movement Type: Spheroidal (Ball and Socket)
Description: Allows a wide range of movements including flexion, extension, abduction, adduction, and rotation.
Movement Type of the Acromioclavicular Joint
Movement Type: Plane or Gliding
Description: Allows limited gliding and rotational movements, contributing to the overall movement of the shoulder girdle.
AC Joint Separation
Description: Trauma to the upper shoulder region resulting in partial or complete tear of the AC or coracoclavicular (CC) ligament, or both.
Cause: Often from a fall onto the tip of the shoulder with the arm in adduction.
Classification: Ranges from a sprain to complete separation of the distal clavicle from the acromion.
Prevalence: Represents nearly half of all athletic shoulder injuries.
Acromioclavicular Dislocation
Description: Injury where the distal clavicle is displaced superiorly.
Cause: Most commonly caused by a fall.
Prevalence: More common in children than adults.
Bankart Lesion
Description: Injury of the anteroinferior aspect of the glenoid labrum, often resulting in a small avulsion fracture in the anteroinferior region of the glenoid rim.
Cause: Often caused by anterior dislocation of the proximal humerus. Repeated dislocation can exacerbate the injury.
Bursitis
Description: Inflammation of the bursae, or fluid-filled sacs enclosing the joints.
Common Joint: Shoulder.
Causes: Repetitive motion, trauma, rheumatoid arthritis, infection.
Effects: Formation of calcification in associated tendons, leading to pain and limitation of joint movement.
Hill-Sachs Defect
Description: Compression fracture of the articular surface of the posterolateral aspect of the humeral head.
Associated With: Often linked to an anterior dislocation of the humeral head.
Idiopathic Chronic Adhesive Capsulitis (Frozen Shoulder)
Description: Disability of the shoulder joint caused by chronic inflammation in and around the joint.
Characteristics: Pain and limitation of motion.
Idiopathic: Of unknown cause.
Impingement Syndrome
Description: Impingement of the greater tuberosity and soft tissues on the coracoacromial ligamentous and osseous arch, generally during abduction of the arm.
Osteoarthritis (Degenerative Joint Disease, DJD)
Description: Non-inflammatory joint disease characterized by gradual deterioration of articular cartilage with hypertrophic bone formation.
Prevalence: Most common type of arthritis, typically occurs in persons older than 50 years, bariatric persons, and athletes.
Osteoporosis
Description: Reduction in the quantity of bone or atrophy of skeletal tissue.
Prevalence: Occurs in postmenopausal women and elderly men.
Effects: Results in scanty and thin bony trabeculae.
Associated Fractures: Most fractures in women older than 50 years are related to osteoporosis.
Rheumatoid Arthritis (RA)
Description: Chronic systemic disease characterized by inflammatory changes in connective tissues.
Initial Inflammation: Begins in synovial membranes, can involve articular cartilage and bony cortex.
Prevalence: More common in women than men.
Radiographic Evidence: Loss of joint space, destruction of cortical bone, and bony deformity.
Rotator Cuff Pathology
Description: Acute or chronic traumatic injury to one or more of the rotator cuff muscles: teres minor, supraspinatus, infraspinatus, and subscapularis.
Common Injury: Impingement of the supraspinatus tendon beneath the acromion, often caused by a subacromial bone spur.
Consequences: Partial or complete tear of the supraspinatus tendon, visible on MRI and sonographic examination.
Shoulder Dislocation
Description: Traumatic removal of the humeral head from the glenoid cavity.
Prevalence: 95% are anterior dislocations, where the humeral head is projected anterior to the glenoid cavity.
Tendonitis
Inflammatory condition of the tendon, usually resulting from a strain.
External Rotation of the Arm on xray
Indicator: Greater tubercle in profile laterally.
Internal Rotation of the Arm
Indicator: Lesser tubercle in profile medially.
AP Proximal Humerus (External Rotation)
Epicondyles: Parallel to IR
Greater Tubercle: Lateral (in profile)
Lesser Tubercle: Anterior
Lateral Proximal Humerus (Internal Rotation)
Epicondyles: Perpendicular to IR
Greater Tubercle: Anterior
Lesser Tubercle: Medial (in profile)
Oblique Proximal Humerus (Neutral Rotation)
Epicondyles: 45° to IR
Greater Tubercle: Not in profile
Lesser Tubercle: Anteriorly (not in profile)
AP Humerus Positioning
Patient Position: Erect or supine
IR Adjustment: Shoulder and elbow joints equidistant from ends of IR
Body Rotation: Toward affected side to bring shoulder and proximal humerus into contact with cassette
Humerus Alignment: Align with long axis of IR or diagonal placement if needed to include both shoulder and elbow joints
Arm Position: Extend hand and forearm as far as tolerated
Arm Adjustment: Abduct arm slightly and gently supinate hand so that epicondyles of elbow are parallel and equidistant from IR
Technical factors for Humerus
Minimum SID: 100 cm or 110 cm
IR Size: Portrait (large enough to include entire humerus) – aim to include both joints
Grid: Use grid for humerus ≥10 cm thickness; non-grid for <10 cm thickness
kVp Range: 70–85
Lateromedial Humerus Projection
Patient Position: Erect with back to IR
Elbow Flexion: Partially flexed
Body Rotation: Rotate toward affected side to bring humerus and shoulder in contact with cassette
Arm Position: Internally rotate arm; epicondyles perpendicular to IR
Mediolateral Humerus Projection
Patient Position: Face patient toward IR and oblique 20° to 30° from PA
Elbow Flexion: Flex elbow 90°
Body Rotation: Adjust as needed for close contact of humerus with IR
Lateral Mid and Distal Humerus Trauma Position
Position: With patient recumbent, perform image as a horizontal beam lateral, placing support under the arm.
Elbow Flexion: Flex elbow if possible; do not attempt to rotate arm.
Projection: Should be 90° from AP.
Image Receptor Placement: Gently place IR between arm and thorax (top of IR to axilla).
CR (Central Ray): Perpendicular to midpoint of distal two-thirds of humerus.
Angles of Proximal Femur
Neck to Shaft: ≈ 125°
Longitudinal: ≈ 10°
Anterior Angle: ≈ 15° to 20°
Anatomic Position of femur
Long axes of feet vertical
Femoral necks partially foreshortened
Lesser trochanters partially visible
15° to 20° Medial Rotation of lower limb
Long axes of feet and lower limbs rotated internally 15° to 20°
Femoral heads and necks in profile
True AP projection of proximal femora
Lesser trochanters not visible or only slightly visible
External Rotation
Long axes of feet and lower limbs equally rotated laterally in a normal relaxed position
Femoral necks greatly foreshortened
Lesser trochanters visible in profile internally
Typical Rotation with Hip Fracture
Long axis of left foot externally rotated (on side of hip fracture)
Unaffected right foot and limb in neutral position
Lesser trochanter on externally rotated (left) limb more visible; neck area foreshortened
Anteroposterior (AP) Compression Injury
Characteristic features:
Symphyseal diastasis
Sacroiliac joint diastasis
What is Symphyseal Diastasis?
Symphyseal diastasis is the separation or widening of the pubic symphysis, often occurring due to trauma, pregnancy, or childbirth, leading to pelvic instability and pain. Symptoms include pelvic pain, difficulty walking, and tenderness around the pubic area, especially after physical exertion.
What is Sacroiliac Joint Diastasis?
Sacroiliac joint diastasis is the abnormal separation or widening of the sacroiliac joint, which can cause lower back pain and pelvic instability, often due to trauma or pregnancy-related factors.
Symptoms include lower back pain, pain in the buttocks or legs, and instability when standing or walking.
Vertical Shear Injury
Vertically oriented fractures of the pubic rami are typically ipsilateral (same-sided)
What are the characteristics of a posterior hip dislocation?
Most common type of hip dislocation.
Affected lower extremity is usually shortened, adducted, and internally rotated.
Femoral head is displaced posteriorly, superiorly, and slightly laterally to the acetabulum, and internally rotated, obscuring the lesser trochanter on the AP view.
On a well-centered AP film, the posteriorly dislocated femoral head appears smaller than the contralateral hip due to geometric magnification.
What are the characteristics of an anterior hip dislocation?
Less common, occurring in 5-18% of cases.
Projects a larger-appearing femoral head.
Lesser trochanter is more visible due to external rotation.
Hip is abducted, and the femoral head is usually inferior to the acetabulum.
Shenton’s line is broken.
How should a patient be positioned for an AP (Mid and Distal) Femur X-ray?
Place the patient in the supine position, with the femur centered to the midline of the table. Provide a pillow for the head.
Align the femur to the CR and to the midline of the table or IR.
Rotate the leg internally approximately 5° for a true AP view, similar to an AP knee. For the proximal femur, rotate the leg 15° to 20° internally, as for an AP hip.
Ensure that the knee joint is included on the IR, considering the x-ray beam’s divergence. The lower margin of the IR should be approximately 5 cm below the knee joint.
What are the technical factors for an AP (Mid and Distal) Femur X-ray?
CR Position: Perpendicular to femur and IR. Direct CR to the midpoint of the IR.
Minimum SID: 100/110 cm
IR Size: 35 × 43 cm, portrait
Grid: Use a grid
kVp Range: 75–85
What is the patient and part position for a Lateral (Mid and Distal) Femur X-ray?
Patient Position: Place patient in the lateral recumbent position, or supine for trauma patients.
Part Position:
Flex knee approximately 45° with the patient on the affected side. Align femur to the midline of the table or IR.
Place the unaffected leg behind the affected leg to prevent over-rotation.
Adjust IR to include the knee joint (lower IR margin should be approximately 2 inches [5 cm] below the knee joint). A second IR may be needed to include the proximal femur and hip in adults.
For trauma patients, perform in AP position with a horizontal beam.
What are the key considerations for imaging the Lateral Mid and Proximal Femur?
Position: Same as for mid-distal femur.
IR Adjustment: Adjust IR to include the hip joint, considering the divergence of the x-ray beam. Palpate the ASIS and place the upper IR margin at this level.
Image Evaluation: Ensure proper anatomy demonstration, true lateral positioning, and correct exposure factors.
What are the key considerations for imaging the Lateral Mid and Proximal Femur?
Position: Same as for mid-distal femur.
IR Adjustment: Adjust IR to include the hip joint, considering the divergence of the x-ray beam. Palpate the ASIS and place the upper IR margin at this level.
Image Evaluation: Ensure proper anatomy demonstration, true lateral positioning, and correct exposure factors.
