The diversity of fracture patterns and anatomical locations dictates the specific indications for plate osteosynthesis. The five main types of plates are:

1.   Neutralization Plate

2.   Compression Plate

3.   Buttress Plate (Support Plate)

4.   Antiglide Plate

5.   Bridge Plate

I. Neutralization Plate

Commonly used in spiral fractures. After the fracture fragments are fixed with lag screws, this plate is applied to neutralize torsional and shear stresses, protecting the interfragmentary lag screws from loosening. (See figure below).

II. Compression Plate

Used for short oblique or transverse fractures to achieve absolute stability and promote primary bone healing. This requires anatomical reduction. By eccentrically placing the screw (loaded drilling), compression is generated across the fracture site as the screw head engages the plate hole.

Technical of Compression Plating:

1. Drawback of a Straight Plate: Compression is achieved only on the near cortex, while the far cortex may actually gap open.

2.   Pre-bending Technique (Plate Contouring): The plate is pre-contoured to achieve uniform, symmetrical compression across the entire fracture site.

3.   Critical Requirement: Gapping of the opposite (far) cortex must be avoided!

Case Example:A short oblique fracture of the humeral shaft treated with a compression plate. (See figure below).

Postoperatively, the far cortex opposite the plate is open, leaving a gap that ultimately led to nonunion. (See figure below).

III. Buttress Plate

1.   The plate must be placed at the "apex" or "vertex" of the fracture line (e.g., on the metaphyseal flare).

2.   If the plate is under-contoured, tightening a screw at the apex will create compression across the fracture.

Example: Insufficient plate contouring led to over-reduction of the fracture upon screw tightening, as indicated by the asterisk (*) in the lower image showing joint surface incongruity. (See figure below).

After readjustment, anatomical reduction was achieved. (See figure below).

IV. Antiglide Plate

Functionally similar to a buttress plate, it is placed at the "axilla" or "apex" of the fracture (positioned obliquely). Its purpose is to prevent shear displacement and axial shortening of the fracture fragment. It does not actively generate compression. (See figure below).

V. Bridge Plate

1. Indication: Comminuted fractures (where individual fixation of fragments is not feasible).

2.   Technical Feature: The plate spans across the proximal and main distal fragments, bridging the comminuted zone without directly fixing the intermediate fragments. All stability is transmitted through the plate (initially, there is no bony support).

Reduction Principle: Anatomical reduction of the comminuted zone is not required. The surgical goals are to restore overall length, alignment, and rotation.

Source: A research article