Content deleted Content added
m Journal cites, Added 3 dois to journal cites using AWB (12158) |
→Clinical use of bone segment navigation: The systems, which were used by Cutting and Watzinger do not meet the criteria of bone segment navigation (see first paragraph), since they still use artificial reference markers instead of natural reference surfaces and achieve only an accuracy of 2 - 4 mm. |
||
(21 intermediate revisions by 13 users not shown) | |||
Line 1:
{{Short description|Surgical method for positioning bone fragments in fractures}}
'''Bone segment navigation''' is a surgical method used to find the anatomical position of displaced bone fragments in fractures, or to position surgically created fragments in craniofacial surgery. Such fragments are later fixed in position by [[osteosynthesis]]. It has been developed for use in [[craniofacial]] and [[oral and maxillofacial surgery]].▼
▲'''Bone segment navigation''' is a surgical method used to find the anatomical position of displaced bone fragments in [[Bone fracture|fractures]], or to position surgically created fragments in [[craniofacial surgery]]. Such fragments are later fixed in position by [[osteosynthesis]]. It has been developed
After an accident or injury, a fracture can be produced and the resulting bony fragments can be displaced. In the oral and maxillofacial area, such a displacement could have a major effect both on facial aesthetics and organ function: a fracture occurring in a bone that delimits the [[orbit (anatomy)|orbit]] can lead to [[diplopia]]; a [[Human mandible|mandibula]]r fracture can induce significant modifications of the [[occlusion (dentistry)|dental occlusion]]; in the same manner, a skull ([[neurocranium]]) fracture can produce an increased [[intracranial pressure]].▼
Bone segment navigation is a patented <ref>Marmulla R (inventor), Carl Zeiss (submitter): System and method for bone segment navigation. United States Patent 6.241.735, 2001.</ref><ref>Marmulla R and Lüth T: Method and device for instrument, bone segment, tissue, and organ navigation, United States Patent 7.079.885, 2006</ref> surgical procedure, using a frameless and markerless registration technique. It uses for the first time natural registration surfaces instead of single artificial x-ray visible markers, in order to achieve a higher precision (1 mm and better).<ref>Marmulla R, Niederdellmann H: Computer-assisted Bone Segment Navigation. In: Journal of Cranio-Maxillo-Facial Surgery. 1998; 26, S. 347–359.</ref> Previous methods of Cutting and Watzinger do not meet the criteria of bone segment navigation.<ref> Marmulla R: Knochensegmentnavigation. Quintessenz-Verlag, Berlin 2000, ISBN 3-87652-869-0.</ref>
In severe congenital malformations of the facial skeleton surgical creation of usually multiple<ref>{{Cite journal|last=Obwegeser|first=HL|date=1969|title=Surgical correction of small or retrodisplaced maxillae. The "dish-face" deformity.|url=|journal=Plast Reconstr Surg.|volume=43|issue=4|pages=351–65|doi=10.1097/00006534-196904000-00003|pmid=|access-date=|via=}}</ref><ref>{{Cite book|title=Craniofacial Surgery 3|last=Cutting|first=C|last2=Grayson|first2=B|last3=Bookstein|first3=F|last4=Kim|first4=H|last5=McCarthy|first5=J|publisher=Monduzzi Editore|year=1991|isbn=9788832300000|editor-last=Caronni|editor-first=EP|___location=Bologna|pages=|chapter=The case for multiple cranio-maxillary osteotomies in Crouzon's disease.|via=}}</ref> bone segments is required with precise movement of these segments to produce a more normal face.▼
▲After an accident or injury, a fracture can be produced and the resulting bony fragments can be displaced. In the oral and maxillofacial area, such a displacement could have a major effect both on facial aesthetics and organ function: a fracture occurring in a bone that delimits the [[orbit (anatomy)|orbit]] can lead to [[diplopia]]; a [[Human mandible|mandibula]]r fracture can induce significant modifications of the [[occlusion (dentistry)|dental occlusion]]; in the same manner, a skull ([[neurocranium]]) fracture can produce an increased [[intracranial pressure]].{{cn|date=January 2022}}
▲In severe congenital malformations of the facial skeleton surgical creation of usually multiple<ref>{{Cite journal|last=Obwegeser|first=HL|date=1969|title=Surgical correction of small or retrodisplaced maxillae.
== Surgical planning and surgical simulation ==
An [[osteotomy]] is a surgical intervention that consists of cutting through bone and repositioning the resulting fragments in the correct anatomical place. To insure optimal repositioning of the bony structures by [[osteotomy]], the intervention can be planned in advance and simulated. The surgical simulation is a key factor in reducing the actual operating time. Often, during this kind of operation, the surgical access to the bone segments is very limited by the presence of the soft tissues: muscles, fat tissue and skin - thus, the correct anatomical repositioning is very difficult to assess, or even impossible. Preoperative planning and simulation on models of the bare bony structures can be done. An alternate strategy is to plan the procedure entirely on a CT scan generated model and output the movement specifications purely numerically.<ref>{{Cite journal|
== Materials and devices needed for preoperative planning and simulation ==
The osteotomies performed in [[orthognathic surgery]] are classically planned on cast models of the tooth-bearing jaws, fixed in an [[articulator]]. For [[edentulous]] patients, the surgical planning may be made by using [[stereolithography|stereolithographic models]]. These tridimensional models are then cut along the planned
Since the 1990s, modern techniques of presurgical planning were developed – allowing the surgeon to plan and simulate the osteotomy in a virtual environment, based on a preoperative [[computed tomography|CT]] or [[MRI]]; this procedure reduces the costs and the duration of creating, positioning, cutting, repositioning and refixing the cast models for each patient.
== Transferring the preoperative planning to the operating theatre ==
[[Image:SSNSchema.jpg|thumb|130 px|left|Schematic representation of the principle of bone segment navigation; DRF1 and DRF2 = IR
The usefulness of the preoperative planning, no matter how accurate, depends on the accuracy of the reproduction of the simulated [[osteotomy]] in the surgical field. The transfer of the planning was mainly based on the surgeon's visual skills. Different guiding headframes were further developed to mechanically guide bone fragment repositioning. {{citation needed|date=October 2018}}
[[Image:SSNimOP.jpg|thumb|Using the [[Surgical Segment Navigator|SSN]] in the operating theatre; 1=IR receiver, 2 and 4=IR Reference devices, 3=SSN-Workstation]]
▲[[Image:SSNSchema.jpg|thumb|Schematic representation of the principle of bone segment navigation; DRF1 and DRF2 = IR Reference devices]]
== Surgical Segment Navigator ==
Initial bone fragment positioning efforts using an electro-magnetic system were abandoned due to the need for an environment without ferrous metals.<ref>{{Cite journal|
Thus, fragments can be very accurately positioned into the target position, predetermined by surgical simulation. More recently a similar system, the [[Surgical Segment Navigator]] (SSN), was developed in 1997 at the [[University of Regensburg|
== References ==
<references />
{{DEFAULTSORT:Bone Segment Navigation}}
[[Category:Oral and maxillofacial surgery]]
[[Category:Computer-assisted surgery]]
[[Category:Surgery]]
[[Category:Health informatics]]
|