Locking Compression Plate (LCP)
DNB Orthopaedics • May 2024 • Paper II • 10 Marks
Introduction
The Locking Compression Plate (LCP) is an internal fixation device that combines the principles of a conventional compression plate with those of a fixed-angle locking plate.
It can therefore function as:
- A conventional compression plate
- A neutralization plate
- A bridging plate
- A fixed-angle internal fixator
Central concept: In conventional plating, stability depends mainly on friction between plate and bone; in locking plating, stability depends on the fixed-angle screw–plate construct.
Basic Design of an LCP
The characteristic feature is the Combi-hole, which allows either a conventional screw or a locking screw.
Dynamic Compression Unit (DCU)
Accepts a conventional cortical/cancellous screw and permits axial compression by eccentric screw placement.
Threaded Portion
Accepts a locking-head screw whose threaded head locks into the plate.
LCP COMBI-HOLE
Conventional side Locking side
↓ ↓
Cortical screw Locking-head screw
↓ ↓
Plate pulled to bone Screw locks to plate
↓ ↓
Friction stability Fixed-angle stability
A. Principles of Locking Compression Plate
1. Fixed-Angle Screw–Plate Construct
The threaded head of a locking screw engages the threaded plate hole. Once locked, the screw and plate behave as a single fixed-angle construct.
The…