ORIF - Plate fixation

The lesser tuberosity is typically displaced anteriorly due to the pull of the subscapularis.

The displaced lesser tuberosity must be reduced and fixed stably (for anatomical shoulder prostheses).

More information about fixation of this fracture type can be found in the AO Surgery Reference Proximal humerus module.

A plate can be used to buttress a lesser tuberosity fragment to increase the stability of a suture fixation. This can be a one-third tubular plate or a 2.7 mm adaptation plate. An example of a completed construct is shown in this illustration.

Sutures in the subscapularis tendon insertion aid manipulation, reduction, and temporary fixation of a lesser tuberosity fracture.

Traction on the sutures helps achieve reduction. When tied, they bring the fragments together and stabilize them.

Sutures placed through the insertions of the subscapularis tendon are the principal fixation technique. With osteoporotic bone, the tendon insertion is often stronger than the bone itself, so that sutures placed through the insertional fibers of the tendon may hold better than screws or sutures placed through bone.

This form of fixation was referred to as a “Tension band suture fixation”. We now prefer the term “Neutralizing suture” because the tension band mechanism cannot be applied consistently to each component of the fracture fixation. An explanation of the limits of the Tension band mechanism/principle can be found here.

In larger lesser tuberosity fragments, especially with extension to the metaphyseal humerus, a buttress plate can be used to increase stability.

It is recommended that this procedure is performed with the patient in a beach chair position.

Patient positioning should be discussed with the anesthetist.

The approach of choice is the deltopectoral approach.

Sutures are inserted into the subscapularis tendon medial to the osteotendinous junction. These provide guides for reduction and temporary fixation of the lesser tuberosity.

Traction on the sutures in the subscapularis tendon aids reduction of the lesser tuberosity.

A periosteal elevator may help to manipulate the lesser tuberosity.

The transverse sutures are tightened and tied to achieve preliminary fixation of the lesser tuberosity fragment.

After preliminary fixation the reduction is checked visually and with image intensification.

All fracture lines should remain closed without steps or gaps between the greater and lesser tuberosities during rotation of the arm. This should be further assessed by image intensification.

An adaptation plate is provisionally fixed to the humeral shaft with a bicortical 2.7 mm cortical screw (a 3.5 mm screw if a one-third tubular plate is applied).

One or two additional bicortical screws are inserted into the humeral shaft. As the stem needs to be avoided, drill obliquely anterior and/or posterior to the stem. It is preferable to position screws both anterior and posterior to the stem.

The C-arm must be directed to allow orthogonal views. Position the arm as necessary to confirm that reduction is satisfactory, fixation is stable, and the screws are of appropriate length.

The aftercare can be divided into four phases of healing:

• Inflammatory phase (week 1–3)
• Early repair phase (week 4–6)
• Late repair and early tissue remodeling phase (week 7–12)
• Remodeling and reintegration phase (week 13 onwards)

Full details on each phase can be found here.