MSK V Elbow.

MSK V Elbow
3 articulations of the elbow
HINGE JOINT




Elbow joint capsule attachments
Anteriorly
Description of the elbow capsule
STRONG
How much valgus resistance does the elbow capsule contribute to in full extension
38%
How much varus resistance does the elbow capsule contribute to in full extension
32%
What does the elbow capsule not respond well to?
Does not respond well to injury or prolonged immobilization and often forms thin scar
tissue leading to flexion contracture

-Even worse than adhesive capsulitits
Medial Collateral Ligament Complex
A.K.A. Ulnar Collateral Ligament:
1.Anterior bundle
2.Posterior bundle
3.Oblique (transverse bundle)- not crossing the joint itself but it is blended with the
posterior band




Lateral Collateral Ligament Complex
1.A.K.A. Radial Collateral Ligament
2.Annular Ligament




Function of MCL

,Stability against valgus stress between 20-130 degrees
Anterior bundle of MCL characteristics
•Strongest and stiffest
Posterior and Oblique Bundles of MCL characteristics
•Forms floor of cubital tunnel and thickens posterior capsule
•Valgus resistance between 60-90 deg of flexion
- Think racquet sports
Function of LCL
-Varus force resistance in small contributions
-Strengthens the joint capsule at the distal part of the proximal radioulnar joint.
Annular ligament function
•Around radial head (80%)
Quadrate Ligament
Function
Olecrenon bursa
•High risk of injury due to blunt or friction trauma
Cubital Tunnel = "Funny Bone" borders and contents
Contents




Anticubital Fossa (a.k.a. cubital fossa) contents
•median nerve, brachial artery, biceps brachii tendon, radial nerve, median cubital
vein
Triangular space on anterior surface of elbow




Borders of anticubital fossa
1.Lateral: brachioradialis and ECRL
2.Medial: pronator teres
3.Proximal: line through humeral condyles
4.Floor: brachialis
Open packed position of the three elbow joints
1. Humeroulnar: 70 deg flex, 10 deg sup

2. Humeroradial: Full ext, full sup

3. Radioulnar: 70 deg flex, 35 deg sup

,closed packed position of the three elbow joints
HU: Full ext, Full sup

HR: 90 flex, 5 sup

RU: 5 deg sup and full ext
capsular patterns of the elbow joints
HU: flexion > ext
Elbow biomechanics
CONCAVE ON CONVEX -> ROLL AND GLIDE ARE IN THE SAME DIRECTION




proximal radioulnar joint biomechanics
•CONVEX RADIAL HEAD MOVING ON A
CONCAVE RADIAL NOTCH

PRONATION = ANTERIOR ROLL OF THE RADIAL HEAD AND POSTERIOR
GLIDE

SUPINATION = POSTERIOR ROLL OF THE RADIAL HEAD AND ANTERIOR
GLIDE
Carrying Angle
•In full extension the ulna deviates laterally = 11- 16 degree acute angle with
longitudinal axis of the humerus
What is the carrying angle due to
(
Normal cubital valgus vs. excessive valgus or varus
(11-16)
*larger angle in women




Carrying angle serves to:
extension
Carrying angle norms for men and woman
•Males: 11-14 degrees
•Females: 13-16 degrees

, What would we use to see swelling in the joint or anything that is going on inside the
joint
MRI with contrast
arthocam
Disabilities of the Shoulder Arm and Hand (DASH)
INCLUDES ADL, WORK, AND SPORTS/PERFORMING
ARTS SECTIONS

SCORING: 0 = NO DISABILITY; 100 = MAXIMAL
DISABILITY

MINIMAL CLINICALY IMPORTANT
DIFFERENCE = 10.83-15 POINTS
NEUROLOGICAL TESTING




Ulnar Nerve (C7-T1) Entrapments Near Elbow
Areas of potential entrapments:

-Arcade of Struthers
-Cubital tunnel
-Two heads of Flexor Carpi Ulnaris
-Deep Flexor-pronator aponeurosis




Median Nerve (C5-T1) Entrapments Near Elbow
•Areas of potential entrapments:

1.Ligament of Struthers
2.Cubital Fossa: compression under the brachialis
3.2 heads of pronator teres muscle
4.Anterior Interosseous nerve (AIN) branches off and goes through pronator teres