Fixator-Assisted Internal Fixation in Periprosthetic Femoral Shaft Fractures
2Orthopaedics, Bnai Zion Medical Center, Israel
3Orthopaedics, Ural Institute of Traumatology and Orthopaedics, Russia
Purpose:
Gaining of proper length and alignment in periprosthetic femoral fractures, nonunions and deformations may be challenging. Fixator-assisted technique can be helpful but its use in different periprosthetic fracture patterns have not yet been defined. Aim of our study was to define optimal implementation of fixator-assisted internal fixation in femoral periprosthetic fractures about hip arthroplasty stems.
Methods:
Fixator-assisted internal fixation was used in the treatment of 117 femoral periprosthetic fractures, hip stems - 97/117: Vancouver B1 – 28 cases (11 cemented), Vancouver ALT – 1, Vancouver B2 – 33 (2 cemented), B3 – 25 (4 cemented), С– 10 (4 cemented). Fractures above total knee implants (Rorabeck-Lewis II)– 20/117.
Mostly locked intramedullary nails with connection to the stem were used for definitive stabilization (100/117). Antegrade nailing was used in fractures above knee implants (13/20). Locked plates (2/20) and retrograde nails (2/20) were used in interprosthetic fractures only. Simplified Ilizarov frames were used to gain alignment and length. Immediate postoperative evaluation included radiological check of length and alignment of the femur, and also position of the stem if it was previously displaced in Vancouver B2-B3 fractures.
Results:
Frame application allowed to restore length and alignment of the segment in all 23 cases of stable stems (B1 and C). In loose stems not only fixation was performed but also reduction of displaced stems.
Three frame types were defined depending on two factors: injury type according to Vancouver classification, and position of the stem tip inside or outside medullary canal. Frame type 1 (Vancouver B1 and C type) is secured to the proximal and distal aspects of the femur. Type 2 (Vancouver B2-B3, stem tip outside the distal fragment) the frame secured to the iliac wing and the distal femur. And frame type 3 (B2-B3 with the stem tip inside the medullary cavity) consists of one arc secured to the distal femur, with connection to an insertion handle of the intramedullary nail.
Conclusion:
Fixator-assisted internal fixation provides easy control of length and alignment including reduction of displaced stem and lengthening of the femur in periprosthetic fractures and their sequelae. Position of the stem tip (inside or outside of medullary cavity) and Vancouver classification appear to be key factors defining optimal frame configuration.