The humerus is the upper arm bone. A fracture of the proximal humerus, the region closest to the shoulder joint, can affect your work and activities of daily living.
Open reduction and internal fixation (ORIF) is a surgical technique employed in severe proximal humerus fractures to restore normal anatomy and improve range of motion and function.
The shoulder is formed by 3 bones:
- Clavicle (collar bone)
- Scapula (shoulder blade)
- Humerus (upper arm bone)
The humerus and scapula articulate or join at the glenohumeral joint.
This joint is held together by a group of muscles and tendons called the rotator cuff.
The parts of the proximal humerus frequently involved in fractures include:
- The head of the humerus
- Greater tuberosity
- Lesser tuberosity
- Surgical neck
Proximal humerus fractures can cause pain and decreased mobility of the arm.
The elderly are more prone to proximal humerus fractures from accidents such as falling on an outstretched arm. They may also occur in young people involved in high-energy accidents.
Most proximal humerus fractures are not displaced and can be treated by a supportive sling and early rehabilitation. However, if fracture fragments are 5 mm apart or the angle between the fragments is more than 45 degrees, they are considered displaced and will require surgical intervention such as open reduction and internal fixation.
Other factors influencing the decision to perform surgery include age of the patient, bone quality, blood supply to the area and ability to tolerate the post-operative rehabilitation.
The open reduction and internal fixation surgery involves the reduction of the fracture and securing the correctly aligned bones to allow healing. You are placed in the beach-chair position to allow shoulder movements and imaging from different angles.
Sedation or general anesthesia are administered.
An incision is made through the anterior and middle heads of the deltoid (shoulder) muscles.
The axillary nerve is identified and protected, and the rotator cuff and proximal humerus are exposed.
The fracture margins are trimmed and prepared, and the fracture bed is washed.
Stay sutures are placed in the tendons of the rotator cuff muscles to gain control of the fracture fragments.
Then your surgeon brings the fractured fragments into the correct anatomic alignment by manipulation and pulling on the stay sutures.
K-wires are used to temporarily secure the fracture fragments.
Once the bones are aligned, strong sutures, screws, or a system of plate and screws are used to hold the bone fragments together.
Imaging tests are performed in different angles to verify the correct alignment of the fragments and position of the plate and screws, and to assess range of motion.
Following surgery there is a minimum period of immobilization after which rehabilitation should begin. As early as the first post-operative day, you will be made to move your arm as much as you can without too much pain. Physical therapy starts with passive/assisted range of motion exercises. Activities of daily living can slowly be introduced but there must be no lifting or shoulder movements against resistance for at least 6 weeks. Strengthening and stretching should then begin gradually with resistance exercises. It is necessary to monitor progress in movement and strength as persistent weakness may indicate a rotator cuff tear or nerve damage.
Advantages & Disadvantages
Open reduction and internal fixation to treat proximal humerus fractures has the following advantages:
- Allows optimal reduction
- Allows visibility and direct access to reduce fracture fragments with advanced devices
- Increased chance of secondary loss of reduction
Risks and complications
As with all operations there is a possibility of certain risks and complications and may include:
- Subacromial impingement (compression and inflammation of structures between acromion of the shoulder blade and humerus head)
- Frozen shoulder (shoulder pain and stiffness)
- Nerve damage
- Penetration of screws into the articular surface of the humeral head
- Avascular necrosis (bone death resulting from compromised blood supply to fracture fragments)