Early treatment of periprosthetic femur fractures consisted solely of allograft and cable fixation, but data on the technique is limited. A small series reported reasonable success, with only 2 out of 19 patients developing nonunion.27 More recently Haddad and colleagues28 reported malunions in 3 out of 19 patients treated with allograft and cables alone. Allograft alone has been largely abandoned in favor of plate fixation, and biomechanical evidence shows that plate and screw or cerclage constructs are more resistant to torsion and lateral bending than allograft with cables alone.29
However, the role of allograft in treatment of periprosthetic femur fractures is not clearly defined. Some authors advocate routinely supplementing plate fixation with allograft28,30 and others go as far as to suggest superior union rates of strut allograft augmented plate fixation when compared to plate fixation alone for periprosthetic fractures around a stable femoral stem.31 However, in that series, the failure rate of 5/11 patients treated with plate alone is higher than current series,12 and others have demonstrated good success without allograft, even with nonlocked plates.32
As recently as 2016, a lateral locking plate supplemented with allograft has been described as a successful technique, with no nonunions reported in a small series.30 However, without a comparison group, it is unclear what role the allograft plays in success in that construct.
Despite some proposed benefits, the additional soft tissue stripping required to place allograft has raised the question of delayed healing and increased infection rate as a result of this technique. A systematic review by Moore and colleagues33 looking at the use of allograft strut in Vancouver B1 fractures found increased time to union (4.4 vs 6.6 months) and deep infection rate (3.8% vs 8.3%) with the use of allograft strut, leading them to recommend cautious use of allograft when treating Vancouver B1 fractures.
With improved fixation strategies available, the role of allograft may be best reserved for patients with inadequate bone stock.
Dual Plate Fixation
Dual plate fixation has been proposed as one mechanism to increase construct strength. A periprosthetic fracture model has shown that, biomechanically, orthogonal plates have higher bending stiffness, torsional stiffness, cycles to failure, and load to failure when compared to a single lateral plate with use of a locking attachment plate proximally.34 Choi and colleagues35 compared lateral locking plates alone, lateral locking plates with allograft, and lateral locking plates with an orthogonal anterior plate and found the addition of an anterior plate resulted in the strongest construct.
Clinically, Müller and colleagues36 reported on a series of 10 patients treated with orthogonal (anterior and lateral) plating for periprosthetic femur fractures, including 3 nonunions. In their series, there was 1 plate failure and they conclude that dual plating is not associated with an increased risk of complications, and can also be used as a salvage procedure.
While the evidence for dual plating is limited, it may provide needed additional stability in certain cases without the added cost and exposure required for allograft.
Minimally Invasive Plate Osteosynthesis
Contrary to the extensive exposure required to place allograft, minimally invasive plate osteosynthesis (MIPO) of periprosthetic femur fractures is advocated by some authors.18,20 Ricci and colleagues18 reported no nonunions in 50 patients treated with indirect reduction techniques and laterally based plating alone without use of allograft. A combination of cables, locking, and nonlocking screws were used. Critical to their technique was preservation of the soft tissue envelope at the level of the fracture.
In further support of MIPO techniques, a systematic review of 1571 periprosthetic hip fractures reported significantly increased risk of nonunion with open approaches when compared to minimally invasive osteosynthesis,16 emphasizing the role of preservation of vascularity in treating these fractures.
Length of Fixation
For some time it was recommended that fixation of Vancouver B1 fractures end 2 cortical diameters below the level of the fracture.37,38 More recently there has been interest in the potential benefits of increased length of fixation.
A biomechanical study comparing long (20-hole) and short (12-hole) plates for periprosthetic fracture with regard to failure found no difference in failure rates between groups.39 While plate length did not appear to affect construct stiffness, the issue of subsequent fracture distal to the construct remains.
Moloney and colleagues40 proposed fixation of Vancouver B1 fractures using plates that span the length of the femur to the level of the femoral condyles to minimize peri-implant failures in osteoporotic patients. In 36 patients treated with standard-length plates, there were 2 fractures distal to the previous fixation compared to no subsequent fractures in 21 patients treated with spanning fixation.