Overcoming Anterior Breaches in the Distal Femur During Long Gamma Nailing

Abstract

Anterior cortical penetration of distal femora when using long gamma nails is well established. To avoid this complication, using the appropriate entry point, a nail with a smaller radius of curvature, and intraoperative imaging is suggested. Despite this, there are times when the guidewire or the nail can abut or even perforate the anterior cortex. This is more likely to occur in patients with scalloped anterior distal femora and increased femoral anterior bowing. The authors overcome this potential problem during surgery by using a bent-tip guidewire. Their technique is cost neutral, safe, and quick. [ Orthopedics . 2019; 42(1):e135–e137.]

Influence of greater trochanteric starting point on distal anterior cortical perforation during antegrade femoral nailing

“…Options to achieve this include the use of bent guide wires and blocking implants. [17][18][19][20][21] Our study demonstrates that 1 adjunctive intraoperative technique to avoid an anteriorly placed nail tip may be to avoid a posterior starting point.…”

“…Many surgeons therefore elect to minimize the risk of anterior distal nail placement during femoral medullary nailing. Options to achieve this include the use of bent guide wires and blocking implants 17–21. Our study demonstrates that 1 adjunctive intraoperative technique to avoid an anteriorly placed nail tip may be to avoid a posterior starting point.…”

Biomechanical Consequences of Nail Insertion Point and Anterior Cortical Perforation for Antegrade Femoral Nailing

“…Although anterior cortical perforation of the distal femur during antegrade nailing only happens at a rate of <1% [20,21], which supports the general findings of the current biomechanical analysis, there is still a finite risk of displaced supracondylar fracture requiring revision surgery [24]. Consequently, several authors describe ways of preventing it, such as bending the guidewire to allow the surgeon to direct it more posteriorly away from the anterior cortex [40,41], using the starting guide pin or the distal locking drill bit as a blocking screw to direct the guidewire posterior in the femoral shaft [40,42], or using as many as 5 bicortical Steinmann pins to guide the nail posteriorly [43]. Of course, there are other risk factors for accidental perforation beyond the control of the surgeon, like natural bowing of the femur which can have a radius of curvature from 52 to 203 cm [44,45] and the built-in bowing of different cephalomedullary nail designs whose radius of curvature has decreased over the years to prevent perforation from 186 to 300 cm (in 2004) [46] to 127 to 200 cm (in 2016) [44].…”