compression osteosynthesis in oral and maxillofacial surgery.pptx

compression osteosynthesis

1. COMPRESSION OSTEOSYNTHESIS DR PRIYADARSHINI LENKA 2 ND JR , OMFS SCB DCH

2. QUESTION COMPRESSION OSTEOSYNTHESIS (2015 , 2023 BHU)

3. HISTORY AND EVOLUTION OF COMPRESSION PLATES

4. Compression osteosynthesis involves rigid fixation of fractures by applying continuous compressive forces to prevent movement and promote healing.  Goal is "Absolute stability" Techniques Used :  Compression plates Lag screws Enhances the likelihood of successful primary bone healing. Helps to stabilize the fracture, minimizing complication such as infection and non-union. Used for minimally oblique fractures with strong bony buttresses for stable compression fixation Compression Osteosynthesis

5. Rigid Fixation of the Pediatric Facial Skeleton Lee, Kevin C. et al. Oral and Maxillofacial Surgery Clinics, Volume 35, Issue 4, 529 - 541 Biological reaction and healing of fractures

6. Tensile forces : Upper surface Compressive forces : Lower surface. Line of zero stress - Neutral axis. BIOMECHANICS MANDIBULAR FRACTURES • Simple beam mechanics acting as a Class Ill lever with condyle acting as fulcrum, masticatory muscles as applied forces and bite load as resistance force

7. Angle region the angle under most functional situations tend to "open" at the superior border Body region More anterior the fracture, the more tendency for torquing of the fragments to occur, causing mediolateral misalignment of the inferior border. Load posterior to the fracture line results in compression at superior margin and tension at inferior margin Loads anterior to the line will lead to reversal of stress patterns

8. Anterior symphysis region Anterior mandible undergoes shearing and torsional (twisting) forces during functional activities There is no muscle support in midline region, compressive stresses in upper and tensile stresses at lower margin

9. • Correspond to neutral zones along which plate can be fixed for favorable stress patterns • Miniplates placed along these osteosynthesis lines restored the stress patterns across the mandible - providing adequate stability Champy's ideal osteosynthesis lines (1976)

10. • Do not have significant muscle forces acting on them. Mid facial Fractures • Tensile forces greatest at the fronto -zygomatic suture and it is the strongest pillar of the zygomatic complex, it is the most important point of fixation. • Best site of fixation to oppose the direction and force of the masseter muscle is the zygomaticomaxillary buttress.

11. BASIC BIOMECHANICS NO FORCES ACTING MINIMAL FIXATION FORCES ACTING ADEQUATE FIXATION TO OVERCOME FORCES

12. FOUR basic principles of fracture management Accurate anatomic reduction Atraumatic operative technique preserving the vitality of bone and soft tissues. Rigid internal fixation that produces a mechanically stable skeletal unit. Avoidance of soft tissue damage and "fracture disease" by allowing early, active, pain-free mobilization of the skeletal unit. AO/ ASIF GUIDELINES FOR FRACTURE MANAGEMENT [MURICE MULLER et all 1958]

13. Compression plating systems All compression plates include at least two pear shaped holes Widest diameter of the hole lies nearest the fracture line The screw is inserted in the narrow part of the hole and at final moment of tightening its head comes to rest in the wider diameter section which is countersunk to receive it.

14. Becker and Machtens ( 1973) 4 hole plates, 5 hole plates (double fractures) Angled plates (angle of mandible fractures) Consists of Retention half: two or more circular retention screws Compression half : oblong sliding hole and oblong retention hole which have either a 27° or 45° bevel against which screw is tightened 1.SELF COMPRESSION PLATE

15. Operative technique • Plate should have at least two holes on each s ide of the fracture. • Adjust using pliers to match bone contour. • Ensure accurate conformity to prevent displacement. • Position towards lower mandible to protect nerves and tooth roots. • Insert and tighten screws for retention holes. • Prepare compression ho les , tighten compression screw first, followed by sliding screw .

16. 1977, Luhr  Spiessl was the first to apply the AO/ ASIF principles to the management of mandibular fractures Design- based on a screw head that, when tightened, slides down on an inclined plane within the plate. "Spherical gliding principle 2.DYNAMIC COMPRESSION PLATES

17. TECHNIQUE

18. distraction Activation of a DCP at the inferior portion of the mandible TENSION BAND An arch bar, superior lag screw, or monocortical miniplate can be used as a tension band to reduce the distraction at the superior border. AO Principles of Fracture ManagementDOI : 10.1055/b-0038-160826 Section 3 Reduction, approaches, and fixation techniques 3.2.3 Tension band principle

19. Eccentric Dynamic Compression Plate (EDCP) 1973,Schmoker, Niederdellman and Schilli developed Provides simultaneous compression across the fracture at the inferior border and at the level of the alveolus. • Inner holes → Basal inter-fragmental compression • Outer holes → Alveolar compression • Eccentric action → No need for tension band • Ideal for → Transverse edentulous mandible fractures • Indication → Mandibular body fractures

20. LAG SCREW FIXATION By Brons & Boering 1970 Management of oblique fractures (symphysis/ angle / condyle) Fixation of bone gratts Orthognathic procedures Median fracture of the mandible in combination with bilateral condylar neck fracture Fixation of condylar fractures LAG SCREW

21. Locking technique Plates designed with threaded holes through which screws pass Two points of fixation Bone Screw hole • ADVANTAGES Precise adaptation of plate to the bone not necessary Plate not compressed against the bone-periosteal viability Low chances of screw loosening Recent advances Low contact DCP (LC-DCP) Modified design of DCP to reduce contact surface J Orthop Sci (2006) 11:118–126 DOI 10.1007/s00776-005-0984-7 Invited review article Internal plate fixation of fractures: short history and recent developments

22. ADVANTAGES & DRAWBACKS OF COMPRESSION PLATES Thicker plates. Increased palpability Excessive compressive forces & resorption / fragmentation Exact overbending of the plates is difficult to achieve When used on oblique fractures >>> overriding & malocclusion Promotes contact healing Linear compression-counteracts torsional forces Excellent stability ADVANTAGES DRAWBACKS Complications of treatment of mandibular fractures with compression plates ( ORAtSURGORALMEDORAL PATHOL ORALRADIOLENDOD1995;79:150-3)

23. CONTRAINDICATION Severely oblique fractures, Comminuted fractures Fractures with bone loss Bone pathology COMPRESSION PLATING (COMPRESSION OSTEOSYNTHESIS) OF MANDIBLE FRACTURES ROBERT M. KELLMAN, MD OPERATIVTEECHNIQUES IN OTOLARYNGOLOGY--HEAD AND NECK SURGERY, VOL 6, NO 2 (JUN), 1995: PP 80-85

24. champy's lines of osteosynthesis original article champy1978[1] Mandibular Osteosynthesis by Miniature Screwed Plates Via a Buccal Approach* Maxime CHAMPY, J. P. LODDÉ, R. SCHMITT, J. H. JAEGER, D. MUSTER Service de Stomatologie et Chirurgie Maxillo- Faciale (Head: Prof. M. Champy , M.D., D.M.D.), Centre Hospitalo-Universitaire de Strasbourg, France • Excessive Compression Risk • Stress Shielding • Occlusion Issues . stress shielding, bone loss, and porosity

25. Complications Early soft tissue infection Late infection malocclusion Malunion Restriction of craniofacial growth nerve injury tooth root injury other…. Pain , palpabilit y, and cold intolerance can occur. These can be easily resolved by removing the hardware after healing is complete. COMPRESSION PLATING (COMPRESSION OSTEOSYNTHESIS) OF MANDIBLE FRACTURES ROBERT M. KELLMAN, MD OPERATIVTEECHNIQUES IN OTOLARYNGOLOGY--HEAD AND NECK SURGERY, VOL 6, NO 2 (JUN), 1995: PP 80-85

26. Oral and maxillofacial trauma - Fonseca (third edition) Maxillofacial injuries - Rowe and Williams Internal fixation of the mandible- A manual of AO/ASIF principles-Bernd Spiessl Peterson's principals of oral and maxillofacial surgery-2^d edition Principles of internal fixation of craniomaxillofacial skeleton and orthognathic surgery-AOCMF COMPRESSION PLATING (COMPRESSION OSTEOSYNTHESIS) OF MANDIBLE FRACTURES ROBERT M. KELLMAN, MD OPERATIVTEECHNIQUES IN OTOLARYNGOLOGY--HEAD AND NECK. SURGERY, VOL 6, NO 2 (JUN), 1995: PP 80-85 REFERENCES

27. thank you

28. minimal invasive plate osteosynthesis resorbable plates In addition, prebent mandible plates are avail- able for reconstructing mandibular defects. Custom- ized mandibular plates save operating room time and are extremely reliable for reconstruction, have lower risks, and overall improved patient satisfac

29. TECHNIQUE Screws are placed in the holes closest to the fracture margin first (inner holes) Then placed in the outer aspect of the screw slot in eccentric position If a six-hole plate is used, screws are then placed in the remaining holes in a passive fashion .

30.  Two types of screws are used : Compression screw Static or passive screw For the plate to be a dynamic compression plate one compression hole should be located in each fragment of the fracture; These holes are usually placed most proximal to the line of fracture. Because the screw movements produced from the inclined planes of these holes oppose each other, the fracture ends will move toward one another relative to the plate

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32.  Interfragmentary mobility present- Non-rigid fixation Characterised by formation of periosteal and endosteal callus Between the fractured segments, a tissue differentiation cascade takes place Stiffness and strength increases until the interfragmentary space is completely ossifies Secondary or Indirect bone union

33. A small plate applied in the zone of compression (inferior bor - der) is very ineffective in neutralizing the muscle forces, and a gap will easily form superiorly in the zone of tension

34. Implications for biomechanics of internal fixation fixation of fractures done for Restoration of tension and pressure trajectories Neutralization of functional stresses developing in the bone

35. Advocated by AO/ASIF Compression plates have the ability to compress the fractured bony margins, helping to bring them closer together Absolute rigidity across fracture lines Compression of fractured bone fragments results in generation of preload-stabilizes the loaded mandible until exceeded by functional loading.

36. AO/ASIF GOALS: ORIF with primary bone healing even under functional loading.

37. Specially designed oval plate holes with an oblique inner surface, that allows eccentrically placed screws to glide down the oblique inner surface of the hole to finally be centred within the plate • During this process the screw which is firmly anchored into one fragment, takes the underlying bone with it, thus facilitating defined movement of both fragments towards fracture line resulting in compression osteosynthesis Sequence of screw fixation After adaptation, holes are drilled in the lateral portion of the gliding holes of the plates adjacent to the fracture Screws partially seated before applying compression Screws placed in outer holes in a passive positio