Material Used in Bone Plate
The most commonly used bone plates are manufactured by using stainless steel which is inexpensive, strong and easy to machine in the manufacturing process. However, plates of stainless steel don’t tolerate stress reversals very well.
Titanium is material which is more biocompatible and enables for bending and shaping plates at the time of surgery.
But titanium is difficult to machine and is expensive material for orthopedic products manufacturers.
Titanium is biologically more inert less likely be a reason of allergies than stainless steel, which have nickel. It is quite likely that this material will become more generally used in the coming time.
It is necessary to remember that screws and plates must be of the same material otherwise implant corrosion is likely to occur.
You can’t use screws of titanium and plate of steel or vice versa.
Different Types of Orthopedic Bone Plates
Dynamic Compression Plate
In the 1st designs of bone plate the holes of screw were round but with dynamic compression plate or DCP, there was a betterment in the design. This bone plate has specially shaped holes in screw which have an inclined plane at the end.
When the screw is placed at this hole end and driven home, it slides down this plane, dragging the plate and producing compression of the bone fragments.
If the bone screw is placed in the screw hole center in a plate it doesn’t make contact with the inclined pane and plate movement relative to the inserted screw doesn’t occur- in this circumstance the screw is said to be placed in a neutral place.
Each hole of screw in a plate is situated in a recess which is shaped to fit the rounded under surface of the bone screw head. This has 3 advantages:
- By burying the screw head in the bone plate, the total construct has a smoother profile which doesn’t irritate soft tissues.
- The contact between screw heads and plate is optimized that prevents stress raisers.
- The screw may be slightly angled relative to the orthopedic plate which may help in attaining optimal placement of screw in the bone.
Limited Contact Dynamic Compression Plates (LCDCP)
Experimental work showed that the under- surface of the DCP, by contact with bone interfered with the supply of blood of the underlying cortex.
The under-surface area of the plate in contact with bone is known as footprint of the plate.
LCDCP or Limited contact dynamic compression plate was an attempt to lessen the footprint of the bone.
The LCDCP has a fluted under surface and reduces the contact between plate bone.
Locking Compression Plates
Locking compression plate is known so because it has bone screws with threaded heads that lock themselves when inserted to threaded plate holes, therefore locking the screw with plate.
This plate also has the conventional holes and can be utilized as system of conventional plate.
From middle of the plate the proximal hole of combi hole is threaded, and distal hole is simple.
The locking or threaded hole adjoins the conventional hole and arrangement is known as combi hole. Locking compression plate has a combi hole which allows the insertion of threaded locking head screws and of standard head screws.
The LCP is also intended with a minimal footprint.
The application of locking plate provides screw/plate constructs in comparison of non-locked screw/plate constructs which is stronger specially to angular forces. It is especially beneficial characteristic in comminuted metaphyseal fractures
Locking plate is used in following circumstances
- In indirect fracture reduction
- Osteoporotic bone fracture
- For bridginh in severely comminuted fractures
- Short segmental fixation
- Percutaneous fixation of fractures
The benefits of locked fixation are following
- Sparing of periosteal blood supply
- Lack of contouring need
- Better holding power
These plates have notched edges to allow bending in any plane that is desired. These plates are useful in anatomical sites, such as the pelvis, the clavicle, and the distal humerus. They are also very adaptable. These plates can be supplied by trauma implants manufacturers.
Angular locked plates/ Anatomical plates
The anatomical plate is used for distal tibial fractures. These are especially contoured plates for different anatomical sites. For instance, distal tibial plate, distal humerus plate or proximal tibial plate.
These bone plates are typical used for juxtarticular or intra fractures because the bone anatomy is exceptional near the joints.