Page 395 - WSAVA2018
P. 395

Your Singapore, the Tropical Garden City
as it is possible to crush the bone in the attempt of achieving adequate friction between bone and the forceps.
Bone clamps are also useful to correct a residual axial malallignment in the saggital plane when plating a
long bone fracture. After the fracture has been grossly aligned, a plate is applied and secured to one fragment, one tip of the clamp (usually a Verbrugen self centering clamp) grasps the anterior or posterior aspect of the bone while the other tip engage on the plate’s border. By closing the clamp, is possible to create a shift of the bone fragments and correct the malallignment.
Special reduction clamps are available to overcome the most difficult situations. The Farabeuf clamp and the pelvic reduction forceps (Jungbluth clamp) are designed to grasp screw heads introduced in both sides of a fracture line. This clamps allow application
of compression, limited lateral displacement and in particular the Jungbluth clamp permits a certain amount of distraction. This clamps are extremely useful for reduction of pelvic fractures.
Hohmann Retractor
A small tipped Hohmann retractor is an extremely useful instrument that can be used to apply levering or as a pusher to achieve reduction. A classic application of
this instrument is in the reduction of simple diaphyseal fractures. The tip of the Hohmann retractor is gently inserted in the fracture gap between the two cortices, is then turned 180 degrees to engage with its tip the cortex of the opposite fragment. Gradual and gentle application of bending force on the retractor allows reduction of the fracture. FIG 4 a- b
 FIG 3-b
In a simple transverse fracture the primary intrinsic stability ensues, allowing removal of the clamps without loss of reduction.
The reduction can be facilitated by the combined levering action of a Hohmann retractor or a periosteal elevator. FIG 3 c
FIG 3-c
All reduction maneuvers with use of bone clamps, depend on the friction between the bone forceps and the bone being greater than that between the bone fragments.
In order to avoid complications related to the use of bone clamps, few guidelines should be followed:
Some of the clamps (e.g. Lohman clamp) cause extensive periosteal stripping. The pointed reduction forceps (Weber tenaculum) are the list atraumatic as they are more gentle to the periosteal sleeve.
Bone fragments should be carefully inspected for fissure fracture lines; application of pressure in a fissured bone fragment or accidental insertion of the tip of a pointed reduction forceps in a fracture line can increase the level of comminution. Weak bone segments can be supported by application of cerclage wire before attempting reduction. Use bone clamps cautiously in young patients,
FIG 4-a
FIG 4-b
  To correct minimal lateral displacement is possible to turn the retractor so that the fragments can slide on each other. When reduction is satisfactory the retractor is removed by turning and bending to decrease the leverage and sliding it out. Another common application of the Hohmann retractor is in the reduction of fractures of the ileum following the same modalities described above. Other instruments such as small osteotome, a periosteal elevator or a scalpel handle can be used to apply leverage in the same fashion of the Hohmann retractor.
Use of Implants for Reduction

   393   394   395   396   397