a brief introduction about orthopaedic plates, its uses and types

1. Dr. Mohammed Roshen
JR Academic
Department Of Orthopaedics
MODERATOR : Dr. Sudeep Kumar

2.  Plates for fixation of long bones were first
recorded by
HANSMANN
(Heidelberg university, Germany, 1886)

3.  Hansmann’s plate
 Bend at the end to protrude through skin
 Attached to bone by screw with long shanks that projected outside the soft tissues

4.  Since 1958, AO has devised plates for long bone fractures starting
with a round holed plate.
 In 1969, dynamic compression plate was developed
 In 1994,LCDCP was created
 In 2001, LCP was developed
 In 2011, LCP with combination holes came into use

5.  Bone plates are like internal splints holding fracture ends of bones together
 Bone plate has two mechanical function
 Transmitting force from one end of bone to the other bypassing the fracture site
 Hold fracture ends together while maintaining proper alignment

6.  FORM- to understand how changes in design of plates has evolved to meet the
needs of the patient
 FUNCTION – to understand how we can use a plate in different ways to achieve
different types of fixation

9.  Titanium is stronger and lighter in weight compared to stainless steel.
 Titanium has a large resistance to repeated loads making it ideal for its
application as an implant.
 Titanium has greater superior strength under repeated load stresses, making this
metal capable of withstanding strain during internal fixation.
 With a lower modulus of elasticity compared to stainless steel, titanium is less
rigid which limits the amount of stress on bone structures.
 Titanium is less prone generating an immune reaction based on the fact that this
material is corrosion resistant compared to stainless steel implants.

10.  DCP (Dynamic Compression Plate)
 LCDCP (Limited Contact Dynamic Compression Plate)
 LCP (Locking Compression Plate)
 RECONSTRUCTION PLATE
 1/3 RD TUBULAR
 LISS (Less Invasive Stabilisation System)

11.  First introduced in 1969 by Danis
 Concept-compression plating
 New hole design- axial compression

14.  3.5mm for forearm,
fibula, clavicle
 4.5mm narrow – humerus
 4.5mm broad - femur

15.  PROBLEMS WITH DCP
 Unstable fixation leads to fatigue and failure
 Compromised blood supply due to intimate contact with underlying cortex
 Refractures after plate removal

16.  the flat undersurface of the DCP interfered with the blood supply of the
underlying cortex onto which it was compressed by the screws.
 The concept of the “footprint” of a plate emerged.
 The "footprint" is the area of the undersurface of the plate in contact with the
underlying bony cortex.

17.  Design change
 Plate footprint reduced
 Advantages
 Minimized kinking at screw holes,
 more contourable,
 reduced fatigue at holes
 Allows more inclination of screw in longitudinal plane and transverse plane

19.  3.5mm – 1/3rd tubular
 4.5mm – semitubular
 Limited stability
 Collared hole

20.  Used for
 Lateral malleoli
 Distal ulna

21.  Deep notches present between holes
 Accurate contouring in any plane
 Used for
 Pelvis
 Acetabulum
 Clavicle
 Distal humerus

23.  Latest evolution
 “INTERNAL FIXATOR”
 Extraperiosteal location of plate

24.  COMBIHOLES
 Advantages of DCP principle and locking head principle
 Flexibility of choice
 Screw holes have been designed to accept either cortical or locking screw

25. TECHNIQUE
 Traditional plating techniques produced stability by:
Compression the plate to the bone surface and
Engaging both cortices, thereby producing a
rectangular hoop with two bicortical screws
 .The locking screws, by achieving angular stability
within the plate holes are able to produce a similar
hoop with just two unicortical screws.

26.  1 – Biomechanically stronger implant as stability not dependent on plate screw
interface . In DCP , failure of one screw can jeopardize whole construct while all
screws of LCP need to be failed in order for LCP to fail.
 2 – Unicortical screws are equivalent In strength of construct to that of DCP
bicortical screws.
 3 – Construct not dependent on quality of host bone for purchase like in DCP.
 4 – MIPO is possible .
 5 – Bridge plating possible

27.  INDICATIONS:
 Complete periarticular fractures
 Comminuted distal femur fracture
 Tibial plateau fracture
 Distal tibia fracture
 Periprosthetic fracture
 Pathological fracture
 Comminuted proximal humerus fracture
 Intra articular distal radius fracture

28.  Preshaped plates with self drilling self
tapping screws with threaded heads.
 Through a small incision (using this jig )
plate is slid along the bone surface.
position of plate and wire are checked
radiologically before insertion of
metaphyseal screw .

29.  NEUTRALIZATION PLATE
 COMPRESSION PLATE
 BUTTRESS PLATE
 BRIDGE PLATE
 TENSION BAND

30.  A neutralization plate acts as a “”bridge”.
 It transmits various forces from one end of the bone to the other, bypassing the
area of the fracture. Its main function is to act as a mechanical link between the
healthy segments of bone above and below the fracture.

31.  plate does not produce any compression at the fracture site
 it is crucial to use a plate that is long enough so that at least three bicortical screw
can be inserted in to each main fragment.

32.  The most common clinical application of the neutralization plate is to protect the
screw fixation of a short oblique fracture, a butterfly fragment or a mildly
comminuted fracture of a long bone, or for the fixation of a segmental bone defect
in combination with bone grafting

33.  A compression plate produces a locking force across a fracture site to which it is
applied. The effect occurs according to Newton's Third Law (action and reaction
are equal opposite). The plate is attached to a bone fragment. It is then pulled
across the fracture site by a device, producing tension in the plate. As a reaction to
this tension, compression is produced at the fracture site across which the plate is
fixed with the screws.

34.  ROLE OF COMPRESSION
 Reduction of the space between the bone fragments to decrease the gap to be bridged by
the new bone
 Compaction of the fracture to force together the interdigitating spicules of bone and
increase the
 Protection of blood supply through enhanced fracture stability.
 Static compression between two fragments maintained over several weak and does not
enhance bone resorption and necrosis.
 Interfragmentary compression leads to absolute stability but has no direct influence on
bone biology or fracture healing

35.  INDICATIONS OF COMPRESSION PLATING:
 Simple transverse oblique fractures of the diaphysis or metaphysis
 Intra articular fractures
 Delayed union or non union
 Closed wedge osteotomy

36.  METHODS OF ACHIEVING COMPRESSION
 With tension device
 Overbending
 DCP/ LCDCP principle
 Contouring the plate
 Additional lag screw through plate

37.  it is recommended for fractures of the femur or humeral shaft, when the gap to be closed
exceeds 1–2 mm, as well as for the compression of osteotomies and nonunions.
 After fixation of the plate to one main fragment, the fracture is reduced and held in
position with a reduction forceps. The tension device is now connected to the plate and
fixed to the bone by a short cortex screw.and then after comression another fragment is
fixed to plate

38.  In oblique fractures the tension device
must be applied in such a way that the
loose fragment locks in the axilla if
compression is produced.

39.  If a straight plate is tensioned on a straight
bone, a transverse fracture gap will open up due
to the eccentric forces acting on the opposite side.

40. • If the plate is slightly prebent prior to the
application (a),
• the gap in the opposite cortex will disappear as
compression is built up (b),
• so that finally the whole fracture is firmly closed
and compressed (c).

42. Dynamic compression principle:
a The holes of the plate are shaped like an inclined
and transverse cylinder.
b–c Like a ball, the screw head slides down the
inclined cylinder.
d–e Due to the shape of the plate hole, the plate is
being moved horizontally when the screw is driven
home.
f The horizontal movement of the head, as it
impacts against the angled side of the hole, results
in movement of the plate and the fracture
fragment already attached to the plate by the first
screw
This leads to compression of the fracture.

43.  A buttress is a construction that resists axial load by
applying force at 90° to the axis of potential
deformity
 Used in metaphyseal/epiphyseal shear or split
fractures
 For application of a buttress plate, the first screw
must be eccentric to prevent sliding of the plate

44.  Antiglide Concepts
 The fracture is oriented such that displacement from axial loading requires the proximal
portion to move to the left.
 The plate acts as a buttress against the proximal portion, prevents it from “sliding” and
in effect prevents displacement from an axial load.
 If this concept is applied to an intraarticular fracture component it is usually referred to
as a buttress plate, and when applied to a diaphyseal fracture it is usually referred to as
an antiglide plate.

45.  Transmits forces from one end of the bone to other bypassing the fracture site
 Mechanical link between the healthy segments of bone above and below the
fracture
 Plate doesn’t produce compression at the fracture site

47.  If a body with a fracture is loaded at each end, over a bending point (fulcrum),
tension (distraction) forces are generated, maximal on the side opposite the
fulcrum, and angulation occurs.

48.  However, if an inelastic band, such as a plate, is anchored to the tension side of
the body, the same load will generate compression across the fracture interface. •
This is known as the tension band principle

49.  PREREQUISITES OF TENSION BAND FIXATION
 Bone which is eccentrically loaded and able to withstand compression
 An intact buttress of the opposite cortex
 A strong plate to withstand the tensile forces
 Plate placement on the tension side of bone
A bone plate will act as a tension band only if it is applied to the tension side of the
bone

51.  The success of bone-plate fixation depends on
 Plate thickness, dimension, geometry, material used
 Screw design, material, number and hold in bone
 Bone- mechanical properties and health
 Construct- placement of plate and direction of load
 Compression between the fragments

52.  When a straight plate is applied to a straight bone surface under static
compression, the near cortex is brought under compression but the far cortex
opens up
 Micromovements with subsequent bone resorption and loss of fixation

53.  Prebent plate results in more uniform compressive contact across the fracture site
without gaping than is achievable with a straight plate

54.  PREBENDING PLATES
 Contour to fit the bone surface snugly
 Make a sharp bend opposite the fracture site, midsection is elevated
 Fix to bone, starting from either side of fracture and then moving outwards
 Plate then compresses the far cortex also
 Apply this technique only to two fragments fractures

55.  The distance between the two screws closest to the fracture on either side of the
fracture
 determines the elasticity of the fracture fixation and distribution of induced
deformation caused by external load

58.  Greater blood loss
 Decreased vascularization beneath the plate
 Exposure of fracture site
 Larger operative soft tissue trauma
 Cosmetic
 Risk of screws pulling out in osteoporotic bone
 Risk of implant failure