Anatomy:

Description:

• The shoulder joint is a multi-axial joint with muscles crossing it to allow shoulder range of motion (ROM)
• The rotator cuff muscles are important in allowing shoulder ROM
• The rotator cuff muscles consists of Subscapularis, Supraspinatus, Infraspinatus and Teres Minor
• Other important shoulder muscles that allow shoulder ROM include long head of Biceps and the Deltoid muscle

• The mechanism usually a fall to the arm or motor vehicle accident
• More common in females

Risk factors:

• Osteoporosis

Presentation:

• Pain
• Swelling
• Deformity
• Decreased ROM

Clinically:

• Swelling and bruising of chest, arm, forearm
• Bone tenderness
• Assess axillary nerve and arterial function and exclude associated injury

Investigations:

• X-ray: AP, axillary and lateral
• CT: for fracture evaluation and surgical planning

The Axillary nerve supplies the Deltoid muscle & the muscle is responsible for shoulder abduction movement. In clinical practice to test nerve motor function: test resisted shoulder abduction with arm at 90° abducted position.

A: Unifocal, extra-articular, 2-part, intact blood supply

B: Bifocal, extra-articular, possible injury to blood supply

C: Articular, involving anatomic neck, high risk of necrosis

Proximal humerus fracture risk factors for AVN include:

• Medial calcar segment < 8mm
• Medial hinge disruption (>2 mm displacement of the diaphysis)
• Medial metaphysis comminution
• Anatomic neck fracture

Hertel criteria predicting increased risk of humeral head AVN. An intact hinge with a longer intact metaphyseal component, the less likelihood of AVN.

Shoulder immobilizer

Shoulder abduction cushion takes off tension on Supraspinatus tendon & greater tuberosity

Greater tuberosity fracture

Greater tuberosity surgical screw fixation

Approach: Deltoid

Fixation: screw fixation

Deltopectoral approach

Plate and screw fixation

Principles of shoulder joint replacement:
Approach: Deltopectoral
Arthroplasty:

• Bone template cuts
• Prepare humerus shaft
• Size humerus head for implant size selection
• Suture tuberosities for fixation to implant
• Implant insertion

Pendulum shoulder range of motion

Hand grip exercise

1. Fractures of the proximal humerus in osteoporotic bone. Ralph Hertel. Osteoporosis Int (2005) 16: S65-S72.
2. Complex proximal humerus fractures: Hertel’s criteria reliability to predict head necrosis. G Campochiaro, M Rebuzzi, P Baudi, F Catani. Musculoskelet Surg. 2015 Sep;99 Supl 1: S9-15.