Unstable posterior pelvic ring injury is severe trauma at any age. Minimally invasive stabilization is preferred for smaller extent of preparation of soft tissues, allowing their implementation in the acute phase of treatment.
According biomechanics, implants can be divided into two basic types: 1st with high compression, 2nd with low compression of the posterior pelvic segment. Group 1 includes iliosacral screws, sacral bars and transsacraltransiliac rods.
Due to the high compression, these implants are suitable for subluxation and dislocation of the SI joint and for transalar sacral fractures (Pohlemann type I). For transforaminal sacral fractures (Pohlemann type II) and central fractures (Pohlemann type III), their use is limited due to excessive compression and in case of comminutive fracture, implants with increased compression are contraindicated for the very high risk of iatrogenic neurological lesion.
The 2nd group (with low compression) includes the following implants: transiliac internal fixator, double transiliac fixator, pedicular-screw plate, transiliac plate, adjustable transiliac plate, minimally invasive spinopelvic fixation and triangular fixation. Low compression implants are suitable for transalar, transforaminal and central sacral fractures, as well as comminutive fractures without the presence of neurological deficit.
Conversely, they are less suitable for SI dislocation. Implants of second group are associated with a lower risk of iatrogenic neurovascular injury than implants with high compression.