plating systems and principles of fixation in maxillofacialtrauma
TRANSCRIPT
PLATING SYSTEMS IN MAXILLOFACIAL TRAUMA
Healing process in fractures
Modes of fracture healingBa
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DIRECTCONTACT HEALING
GAP HEALINGINDIRECT
Fracture fixations
Fixation systems
Load bearing
Load sharing
Load bearing system
plate bears the functional load at the fracture site
accomplished with a locking reconstruction plate.
Clinical uses are the management of atrophic edentulous fractures, comminuted fractures and complex mandibular fractures.
Load sharing system
RIGID and SEMIRIGID FIXATION Does not allow micromotion of fracture segments during
functional movements Absolute rigid fixation not necessary for successful healing(Selection of Internal Fixation Devices for Mandibular Fractures: How Much Fixation Is Enough? Edward Ellis Seminars in Plastic Surgery 2002; 16(3): 229-240DOI: 10.1055/s-2002-34430)
Additional plates required to establish absolute rigidity- increases complication rate
(Ellis, Edward, and Lee R. Walker. "Treatment of mandibular angle fractures using one noncompression miniplate." Journal of oral and maxillofacial surgery 54.7 (1996): 864-871.)
GOALS OF FIXATION
REDUCTION OF BONE FRAGMENTS
STABLE FIXATION
PRESERVATION OF BLOOD SUPPLY
EARLY FUNCTIONAL MOBILISATION
PLATING SYSTEMS
MONOCORTICAL MINIPLATE FIXATION SYSTEM
MICROPLATE FIXATION
COMPRESSION PLATES
LOCKING PLATES
RECONSTRUCTION PLATES
BIODEGRADABLE PLATES
MINIPLATE FIXATION SYSTEM
MITCHEL et al 1960s, CHAMPY et al 1976
Goal-to provide stable fracture reduction without interfragmentary compression or MMF
Advantages-reduced size, smaller incisions and less tissue dissection,less paplpable, reduced necessity of removal
screws are monocortical – can be placed in areas adjascent to tooth roots with minimal risk of injury
Disadvantages Decreased rigidity- torsional movements under
functional loading Cannot be used in comminuted fractues Functional restriction recommended
MICROPLATE FIXATION SYSTEM
Muscular forces on midface skeleton are much less
Thinner and malleable microplates used
Low profile- advantageous in areas of minimum overlying
soft tissue
Application through smaller incisions in aesthetically
sensitive areas
Can be used for fixation of bones in Cranium , orbital rim, zygomatic process, anterior
maxilla and NOE complex
Compression plating system load-sharing osteosynthesis –dynamic,eccentric dynamic EDCP- used when tension band not possible-edentulous,
impacted third molar,avulsion of bone from fracture ensures good interfragmentary compression and thus
good bony buttressing
As the eccentrically placed compression screws are tightened, the head moves down the ramp and the bone is compressed together
Plate must be slightly overbentTo close lingual gap(1-2mm)
Indicated in nonoblique fractures with good bony apposition after reduction
Disadvantages- technique sensitive,plate should be precisely adapted to bone
Use in oblique fractures- can lead to overriding segments
Locking plate system
Plates have threaded holes-thus two separate points of fixation for each screw
Screw locks to plate independent of bone-fracture stability without direct bone contact
Thus precise plate adaptation not manadatory
More viable periosteum as plate does not compress bone
Minimises complications with loose screws
Can be used in severe oblique fractures, comminuted fractures and fractures with bone loss
Reconstruction plates Load bearing In cases of bone loss, gross instability or severe
comminuted fractures, edentulous atrophic mandibles The plate must be long enough so that there can be a
minimum of three or preferably four screws on each side of the fracture.
The screws adjacent to the fracture should be at least 7 mm away from the fracture line.
Bioresorbable plating system Metallic plates- growth restriction and plate translocation Bioresorbable plates- SR-PLA, SR PGA Advantage-iitial rigid fixation.as bone heals-plate
resorbs, reduces stress shielding effect Disadvantages-long resorption time, sterile fluid
accumulations have been reported, less stable than conventional systems