- •Dedication
- •Citation
- •Preface
- •Contents
- •1 Anatomy of the Craniofacial Region
- •1.1 Anterior Skull Base
- •1.1.1 Cribriform Plate/Crista Galli
- •1.1.2 Fossa Olfactoria
- •1.1.3 Roof of the Orbit
- •1.1.4 Dura
- •1.1.5 Arterial Supply: Skull Base/Dura
- •1.2 Paranasal Sinuses
- •1.2.1 Frontal Sinus
- •1.2.2 Ethmoid
- •1.2.3 Sphenoid
- •1.3 Midface Skeleton
- •1.4 Subcranial and Midface Skeleton
- •References
- •2 Radiology of Craniofacial Fractures
- •2.1 Conventional X-Rays
- •2.2 Computed Tomography
- •2.3 Magnetic Resonance Imaging (MRI)
- •2.4 Ultrasonography
- •2.5 Diagnostic Algorithm
- •2.5.1 General Considerations
- •2.5.2 Craniocerebral Trauma
- •2.5.2.1 The Initial CT After Trauma
- •2.5.3 Skull Base Fractures
- •2.5.4 Midface Fractures
- •References
- •3 Classification of Craniofacial Fractures
- •3.1 Frontobasal: Frontofacial Fractures
- •3.1.1.1 Type 1
- •3.1.1.2 Type 2
- •3.1.1.3 Type 3
- •3.1.1.4 Type 4
- •3.2 Midface Fractures
- •3.2.1 Standard Classifications
- •3.2.2 Central Midface Fractures
- •3.2.3 Centrolateral Midface Fractures
- •3.2.4 Skull Base and Fracture Levels in the Region of the Septum
- •3.2.5 Lateral Midface Fractures
- •3.2.6 Midface: Combined Fractures
- •3.2.8 Cranio-Frontal Fractures
- •3.3. Craniofacial Fractures
- •3.3.1 Skull Base-Related Classification
- •3.3.2 Subcranial Facial Fractures
- •3.3.3 Craniofacial Fractures
- •3.3.4 Central Cranio-Frontal Fractures
- •3.3.5 Lateral Cranio-Orbital Fractures
- •References
- •4 Mechanisms of Craniofacial Fractures
- •4.1 Fractures of the Skull Base
- •4.1.1 Burst Fractures
- •4.1.2 Bending Fractures
- •4.2 Frontofacial: Frontobasal Fractures
- •4.2.1 Fracture Mechanism
- •4.3 Midfacial: Frontobasal Fractures
- •4.3.1 Trauma Factors
- •4.3.2 Impact Forces and Vectors
- •4.3.3.1 Degrees of Absorption
- •4.3.4 Impact Surface
- •4.3.4.1 Small Impact Surface
- •4.3.4.2 Large Impact Surface
- •4.3.5 Position of the Skull
- •4.3.5.1 Proclination
- •4.3.5.2 Reclination
- •References
- •5.1 Epidemiology
- •5.2.1 Frequency
- •5.2.2 Localization
- •5.3 Midface: Skull Base Fractures
- •5.3.2 Dural Injuries
- •5.3.2.1 Frequency
- •5.3.2.2 Localization
- •5.4 Cranio-Fronto-Ethmoidal Fractures
- •5.4.1 Frontal Sinus: Midface Fractures
- •5.5 Distribution According to Age
- •5.6 Distribution According to Gender
- •5.7 Associated Injuries
- •5.7.2 Eye Injuries
- •5.7.3 Facial Soft-Tissue Injuries
- •5.8 Special Fractures and Complications
- •5.8.1 Penetrating Injuries
- •5.8.3 Complicating Effects
- •5.8.3.1 Nose: Nasal Septum – Nasolacrimal Duct
- •5.8.3.2 Orbit
- •5.8.3.3 Ethmoid
- •References
- •6 Craniofacial Fracture Symptoms
- •6.1.1.1 Liquorrhea
- •Fistulas
- •Multiplicity
- •Time of Manifestation
- •Clinical Evidence of Liquorrhea
- •Chemical Liquor Diagnostic
- •Glucose-Protein Test
- •Immunological Liquor Diagnostic
- •Beta-2 Transferrin Determination
- •Beta-Trace Protein
- •Liquor Marking Methods
- •6.1.1.2 Pneumatocephalus
- •6.1.1.3 Meningitis
- •6.1.2.1 Lesions of the Cranial Nerves
- •Olfactory Nerves
- •Oculomotor Nerve
- •Trochlear Nerve
- •Abducent Nerve
- •Optic Nerve
- •Loss of Vision in Midface Fractures
- •Location of Optic Nerve Lesions
- •Clinical Appearance
- •Primary CT Signs
- •Secondary CT Signs
- •Additional Injuries
- •Operating Indications/Decompression
- •Decompression of the Orbital Cavity
- •Decompression of the Optic Canal
- •Therapy/Prognosis
- •6.1.2.2 Injuries at the Cranio-Orbital Junction
- •Frequency
- •Superior Orbital Fissure Syndrome (SOFS)
- •The Complete SOFS
- •Incomplete SOFS
- •Hemorrhagic Compression Syndrome (HCS)
- •Orbital Apex Syndrome (OAS)
- •Clivus Syndrome
- •6.1.2.3 Vascular Injuries in Skull Base Trauma
- •Cavernous Sinus Syndrome
- •Thrombosis of the Superior Ophthalmic Vein
- •6.1.3.2 Hemorrhage in the Skull Base Region
- •Basal Mucosal Hemorrhage
- •Hemorrhage in Frontal Skull Base Fractures
- •6.3.1.1 Emphysema
- •Orbital Emphysema
- •6.2 Midface Injuries (Clinical Signs)
- •6.2.1 Central Midface Fractures without Abnormal Occlusion (NOE Fractures)
- •6.2.2 Central Midface Fractures with Abnormal Occlusion (Le Fort I and II)
- •6.2.4 Lateral Midface Fractures
- •6.3 Orbital Injuries
- •6.3.1 Orbital Soft-Tissue Injuries
- •6.3.1.1 Minor Eye Injury
- •6.3.1.2 Nonperforating Injury of the Globe
- •6.3.1.3 Perforating Injury of the Globe (2%)
- •6.3.2 Orbital Wall Fractures
- •6.3.2.1 Fracture Frequency
- •6.3.3 Fracture Localization
- •6.3.3.1 Orbital Floor Fractures
- •6.3.3.2 Medial Orbital Wall Fractures
- •6.3.3.4 Multiple Wall Fractures
- •6.3.4 Fracture Signs
- •6.3.4.1 Clinical Manifestations
- •6.3.4.2 Change in Globe Position
- •6.3.4.3 Enophthalmus
- •6.3.4.4 Exophthalmus
- •6.3.4.5 Vertical Displacement of the Globe
- •6.3.4.7 Retraction Syndrome
- •6.3.4.8 Disturbances of Eye Motility
- •References
- •7.1 Intracranial Injuries
- •7.2 Management of Skull Base and Dural Injury
- •7.2.1 Skullbase Fractures with CSF Leakage
- •7.2.2 Skullbase Fractures with CSF Leak without Severe TBI
- •7.2.3 Skullbase Fractures with CSF Leak with Severe TBI
- •7.2.4.1 Skullbase Fractures with Spontaneously Ceased CSF Leakage
- •References
- •8 Surgical Repair of Craniofacial Fractures
- •8.1 Indications for Surgery
- •8.1.2 Semi-Elective Surgery for Frontobasal and Midface Fractures
- •8.1.3 No Surgical Indication
- •8.2 Surgical Timing
- •8.2.1 Evaluation
- •8.2.1.1 Neurosurgical Aspects
- •8.2.1.2 Maxillofacial Surgical Aspects
- •8.2.2 Surgical Timing
- •8.2.2.3 Elective Primary Treatment
- •8.2.2.4 Delayed Primary Treatment
- •8.2.2.5 Secondary Treatment
- •8.3 Surgical Approaches
- •8.3.1 Strategy for Interdisciplinary Approach (Decision Criteria)
- •8.3.1.2 Approach Strategy: Transfacial-Frontoorbital or Transfrontal-Subcranial
- •8.4.1 Indications
- •8.4.2.1 Coronal Approach
- •8.4.2.2 Osteoplastic Craniotomy
- •8.4.2.3 Skull Base Exposition
- •Technical Aspects
- •Technical Aspects
- •8.5 Transfrontal-Subcranial Approach
- •8.5.1 Indications
- •8.5.2 Surgical Principle
- •8.5.3 Subcranial Surgical Technique
- •8.6 Transfacial Approach
- •8.6.1 Indications
- •8.6.2 Surgical Principle
- •8.6.4.1 Frontal Sinus
- •8.6.4.2 Ethmoid/Cribriform Plate
- •8.6.4.3 Sphenoid
- •8.7 Endonasal-Endoscopical Approach
- •8.7.2 Sphenoid Fractures
- •References
- •9.1 Principles of Dural Reconstruction
- •9.2 Dural Substitutes
- •9.2.1 Autogenous Grafts
- •9.2.2 Allogeneic Transplants
- •9.2.2.1 Lyophilized Dura
- •9.2.2.2 Collagenous Compounds
- •9.3 Principles of Skull Base Reconstruction
- •9.3.1 Debridement of the Ethmoid Cells
- •9.3.3 Skull Base Repair
- •9.3.3.1 Extradural Skull Base Repair
- •9.3.3.2 Intradural Skull Base Occlusion
- •9.4 Skull Base Treatment/Own Statistics
- •References
- •10 Bone Grafts
- •10.1 Indications
- •10.1.1 Midface
- •10.2 Autogenous Bone Grafts
- •10.2.1 Split Calvarial Grafts
- •10.2.2 Bone Dust/Bone Chips
- •10.2.3 Autogenous Grafts from the Iliac Crest
- •References
- •11 Osteosynthesis of Craniofacial Fractures
- •11.1 Biomechanics: Facial Skeleton
- •11.3 Osteosynthesis of the Midface
- •11.3.1 Plating Systems
- •11.3.2 Miniplates: Microplates
- •11.3.3 Screw Systems
- •11.4 Surgical Procedure: Osteosynthesis of the Midface
- •11.4.1 Different Plate Sizes: Indication
- •11.4.2 Fracture-Related Osteosynthesis
- •11.4.2.1 Surgical Approaches
- •11.4.2.2 Lateral Midface Fractures
- •11.4.2.4 Complex Midfacial Fractures
- •11.5.1 Mesh-Systems
- •11.5.2 Indications and Advantages
- •References
- •References
- •12.1 Craniofacial Fractures
- •12.1.1 Concept of Reconstruction
- •12.1.5 Own Procedure: Statistics
- •12.2 NOE Fractures
- •12.3.1 Concept of Reconstruction
- •12.4 Zygomatico-Orbito-Cranial Fractures
- •12.5 Craniofrontal Fractures (CCF)
- •12.5.1 Concept of Reconstruction
- •12.5.6 Fractures of the Frontal Sinus with Comminution of the Infundibulum
- •12.6 Own Statistics
- •13.1 Infections and Abscesses
- •13.2 Osteomyelitis
- •13.3 Recurrent Liquorrhea
- •13.4 Hematoma: Central Edema
- •13.5 Subdural Hygroma
- •13.6 Frontal Sinus: Complications
- •13.7 Functional Neurological Deficits
- •13.8 Meningitis
- •13.9 Facial Contour Irregularities
- •13.10 Conclusion
- •References
- •14.1.1 Autogenous Grafts
- •14.1.1.1 Split Calvarial Grafts
- •14.1.1.2 Cartilage Grafts
- •14.1.3.1 Synthetic Calcium Phosphates
- •14.1.3.2 Synthetic Polymers
- •14.1.4 Titanium-Mesh
- •References
- •15.1 Overall Objective
- •15.2 Patient-Related Conditions
- •15.2.1 Size and Location of the Defect
- •15.2.1.1 Examples
- •15.2.2 General Health Status
- •15.2.3 Neurological Status
- •15.2.4 Patient’s Wish
- •15.2.5 Treatment Plan
- •15.2.6 Technical Aspects
- •15.3 New Developments
- •15.3 1.1 The SLM process
- •15.3.2 PEEK-Implants
- •15.3.3 Outlook
- •References
- •Index
11.4 Surgical Procedure: Osteosynthesis of the Midface |
183 |
|
|
required, as bending with pliers results in immanent structural changes to the plate. Mesh-plates are particularly used for reconstructing comminuted fractures.
Miniplates are available in varying thicknesses, form, and screw diameter (Jackson et al. 1986; Greenberg and Prein 2002)
Miniplates – types (1.5/2.0 mm)a |
Plate thickness 0.9 mm |
Microplates – types (1.0/1.3 mm)a |
Plate thickness 0.5 mm |
aScrew diameter |
|
11.3.3 Screw Systems
• Screw types
Screws are subdivided according to their diameter and thread. In facial surgery, predominantly screws with a thread reaching along the total length of the screw are used. The thread runs asymmetrically to the screw core.
Screw sizes lie between 1.0- and 2.5-mm thread diameter. Emergency screws are available for the majority of standard screws, which have slightly larger dimensions. The screws are retained in the bone through friction produced by the thread (Phillips and Rahn 1989).
There are two different systems implemented in creating threads:
•A thread produced by a self-cutting screw
•A pre-cut thread produced by a screw tap
Self-cutting screws are based on the principle of the wood screw. A burr hole with a diameter slightly smaller than that of the screw is drilled into the bone and the screw is placed into it.
Self-cutting screws are differentiated into two different types:
•Thread-cutting screws
•Thread-forming screws
In the thread-cutting screw, where the principles of fixation and thread-cutting are combined, there are two to three slits at the tip of the screw, which collect the bone dust produced by screwing and simultaneous thread-cutting.
In the thread-forming screw the thread is pressed into the bone. There are no slits to collect the bone dust. Locally, high pressure strains occur, which may lead to microfractures in the surrounding bone.
The optimized construction principle in the self-cutting screws ensures maximum stability. Together with the complimentary instruments, surgery is considerably simplified and shortened (Schmoker et al. 1982; Greenberg and Prein 2002).
• Screw fixation
One differentiates between a monocortical and bicortical screw fixation. With monocortical fixation, stability is gained by penetration of only one cortical layer. The opposite cortex remains untouched. In the facialskeletal area it is noteworthy that bicortical bone is only to be found in the mandible; this is the only significant area for bicortical fixation. Here, the outer and inner cortexes are used for stabilization.
11.4 Surgical Procedure: Osteosynthesis
of the Midface
Osteosynthesis in midface fractures is orientated according to the course of the vertical and horizontal struts. Despite the fine and gracile bone structure in the mid-face, miniand microplates can be fixed in almost any position with sufficient stability (Yaremchuk et al. 1992; Wolfe and Baker 1993). Whilst microplates are primarily used to treat fractures of the fine nonloadbearing bone sectors (for example, the naso-ethmoidal, infraorbital, and frontal regions), the stronger miniplates are used for stabilizing the load-bearing, vertical osseus struts in the zygomatic and maxillary regions (Fonseca and Walker 1991; Prein et al. 1991, 1998).
11.4.1 Different Plate Sizes: Indication
As a general rule, in the region of the load-bearing trajectories 2.0-mm miniplates are used, whilst in neutral, nonload-bearing areas 1.5-mm miniplates are used. In fine nonload-bearing regions of very thin bone, 1.3- mm microplates can be applied. The thickness of the skin in delicate regions, such as the periorbital and nasal areas, should be taken into consideration.