- See:
-
Enhancement of Fixator Stability:
-
Ilizarov Menu:
-
Ring characteristics:
-
Safe Zone of Pin Insertion:
-
Foot Inclusion:
-
Synthes Hybrid Fixator
-
Wire Insertion Technique
- Discussion:
- in the report by D. Paley and DC Maar (Journal of Orthopaedic Trauma Vol 14. No 2. 2000 p 76), the authors report on 19 patients treated with Ilizarov devices;
- mean bone defect was 10 cm in length, and the mean external fixation time was 16 months;
- 10 patients required debridement of the bone ends and/or bone grafting;
- functional results were graded as 12 excellent, 6 good, and one poor;
- there were 22 minor complications and 16 major complications;
- PreOp:
- Exam:
- knee ligament injuries:
- skin abrasions / open fracture
- distal sensation and pulses (check dp while compressing pt and vice versa);
- consider
compartment syndrome
- ankle range of motion;
- Radiographs:
- length of space between tibial plateau and fracture;
- length of fracture;
- length of space between fracture and tibial plafond;
- associated fibular fractures;
- Templating: 
- use opposite normal extemity to help template ring sizes;
- two finger breadths of clearances are required;
- more space is required posteriorly than anteriorly;
- space between inner rings must be > length of fracture comminution
- assess potential for transfibular
wires (contra w/ fractures)
- w/
open or distal frx consider need for
foot inclusion;
- Frame Construction:
- in most cases, the frame should be inserted preoperatively to save time;
- two half rings are selected that are 2-3 cm larger than the major diameter of the injured limb (less space is needed anterior to the tibia);
- the rings are positioned in the same plane and a bolt and nut anchor together both ends of the half rings;
- typically, a 4
ring assembly in required w/ 2 rings proximal and distal to frx site;
- most proximal ring in tibial mounting can be open section ring attached to complete ring, allowing maximum flexion & providing two levels of fixation;
- two rings are used on large frags, & ring & drop post used for smaller fragments;
- two proximal & distal
rings are connected via two telescoping rods of appropriate length (the inner rings must span frx comminution);
-
threaded rods:
- initially, only a single long anterior and posterior threaded rod is used to connect the rings together;
- this leaves plenty of space medially and laterally for insertion of wires and half pins;
- once fixation is complete, two additional threaded rods can be placed;
-
plane for fracture site compression:
- the configuration should be planned in such a way that compression can be applised between the ring which span the fracture site;
- consider using the special quadrangular nuts to connect the threaded rods;
- these nuts will help control even compression across the frx site;
- Frame Construction - Proximal Fractures:
- a 5/8 ring can be mounted on top of a complete ring, w/ three points of fixation using threaded hexagonal sockets;
- the 5/8 ring can be positioned just below the joint line (or at the level of the fibular head), but will still allow knee flexion;
- alternatively, two 5/8 rings can be stacked together (connected by hexagonal sockets) and these are then connected to the distal rings w/ arch connetors;
- the disadvantage of this configuration, however, is that the 5/8 ring has less stability than a full ring (and therefore a 5/8 ring should generally
be attached to a full ring for optimal stability);
- in the report by J Geller et al (Journal Orthopaedic Trauma Vol 14, No 7, 502-504), the authors stress the importance of anterior
placement of the oblique tension wires in the proximal tibia inorder to resist the forces occuring in the saggital plane;
- the angle of intersection of these wires should be greater than 60 deg for optimal stability;
- Frame Construction - Distal Fractures:
- w/ minimal plafond displacement, 3 sets of
wires & rings are used:
- one just above the plafond, the other in proximal tibia, and third through the os calcis.
- some distraction is possible between 2 distal rings, and reduction of metaphyseal fragments is facilitated
by application of tension to
wires with stop nuts;
- Surgical Stratedgy:
- preliminary reduction of fracture;
- insertion of transverse proximal and distal wires wires perpendicular to the knee and ankle joint lines;
- application of frame;
- tensioning of proximal and distal wires;
- frame brought to the wires (wires are not brought to the frame);
- this achieves partial reduction in the coronal plane and helps to suspend the leg in the middle of the frames;
- application of distraction across the fracture site if shortening is present;
- Surgical Technique:
- positioning:
- supine position, hip bump, and flouro on opposite side of table;
- the combination of a large hip bump and a sterile "foot bump" will create a large berth underneath the leg which facilitates insertion of wires and application of the frame;
- reduction:
- traction will usually achieve an approximate reduction;
- use Russe method to ensure proper rotation (tubercle to bi-malleolar axis);
- application of frame:
- open the frame on one side (like a book) and place around the leg;
- coupling bolts are aligned parallel to the crest of tibia;
- ensure that there is proper clearance with at least one fingerbreadth of space anteriorly and two finger breadth of clearance posteriorly;
- too much clearance, however, dramatically reduces the stiffness of the construct;
- the leg can be suspended within the rings by using suction tubing tied across the bottom of the leg and over the top of the ring;
- coronal wires and frame attachement:
- see:
safe zone of pin insertion and
wires insertion techniques:
-
proximal coronal plane reference wire:
- wire is placed at level of & parallel to knee joint and marked;
- a wire is then placed approx one cm below joint line and marked;
-
distal coronal plane wire:
- is placed prior to the remaining proximal wires;
- a wire is placed transverse to ankle joint and marked;
- the distal wire is driven across the fracture site;
- frame attachment: frame is attached to the proximal and distal
wires;
-
mid-shaft wires:
- w/ residual displacement at the frx site, olive wires can be inserted on opposite sides of the frx and are tensioned until
frx reduction is achieved;
- remaining proximal wires:
-
medial face wire:
- inserted from posteromedial side of tibia to antero-lateral side;
- flexing the knee may help avoid the pes anserinus;
-
transfibular
- is driven across tibia to exit on anteromedial surface;
- ensure that this
wire is not too distal so as to have the drop post encroach on the fracture site;
- remaining distal wires:
- see:
safe zones and
wires insertion techniques:
- ensure that there is proper rotational alignment;
- ensure that
rings remain centralized;
- ensure that the fracture is reduced;
- use the Russe method to measure the bi-malleolar axis (measured off the tubercle) on the normal leg to help judge rotation off the fractured leg;
- remaining
wires: are attached to remaining
rings;
- half pins: half pins are attached to appropriate
rings;
- Post Op:
- calcaneal
wires are removed at six weeks, & ROM exercises are started;
- in cases w/ severe articular comminution, proceed w/ second stage at about 15 days when the soft tissues were healed;
Limb Reconstruction by Free-Tissue Transfer Combined With the Ilizarov Method.
Tibial fractures. The Ilizarov alternative.
