New tip-apex distance and calcar-referenced tip-apex distance cut-offs may be the best predictors for cut-out risk after intramedullary fixation of proximal femur fractures

Abstract

Cut-out is one of the most common mechanical failures in the internal fixation of trochanteric hip fractures. The tip-apex distance (TAD), and the calcar-referenced tip apex distance (CalTAD) are the radiographic parameters that most predict the risk of cut-out. The optimal CalTAD value has not yet been defined, but the optimal TAD value is reported as 25 mm or less. However, this cut-off is highly specific but poorly sensitive. The aim of this study was to determine highly specific and sensitive TAD and CalTAD values and shed light on the role of other clinical variables. A total of 604 patients were included in this retrospective cross-sectional study. For each patient the following data were recorded: number of cut-out, AO/OTA classification, quality of the reduction, type of nail, cervicodiaphyseal angle, type of distal locking, post-operative weight-bearing, TAD and CalTAD values, and the position of the screw head in the femoral head according to the Cleveland system. The incidence of cut-out across the sample was 3.1%. The median TAD in the cut-out group was 38.72, while in the no cut-out group it was 22.16. The median CalTAD in the cut-out group was 39.34, while in the no cut-out group it was 22.19. The cut-off values for TAD and CalTAD with highest value of sensitivity and specificity for the risk of cut-out were 34.8 and 35.2, respectively. The incidence of cut-out can be reduced by performing careful minimal reduction and ensuring stable fixation by avoiding TAD > 34.8 mm and CalTAD > 35.2 mm.

Are The Lateral Wall Reduction And Ideal Tip-Apex Distance Important In Reverse Oblique And Transverse Intertrochanteric Femoral Fractures (31-A3) Treated With Gamma Nail?

“…Moreover, the correlation between TAD and fixation failure was not proven in our findings. In general, a TAD <25mm is recommended to lessen the risk of fixation failure in intramedullary hip nails, although evidence for this is limited [13] and several authors have reported that longer TAD and calcar-referenced tip-apex distance (CalTAD) do not, in fact, increase cutout risk [14]. In our study, 29% of patients had a TAD >25 mm, and yet none of them presented a mechanical failure.…”

Double lag-screw compression for optimal fixation of intertrochanteric fractures with large fragment gap: A technical note

“…Particular attention should be paid to fracture site reduction and lag screw positioning to diminish mechanical complications such as lag screw cut-out, which aggravate morbidity and mortality associated with proximal femur fractures [ 4 ]. Studies have provided the first clinical evidence bolstering the validity and reliability of CalTAD as a predictor of lag screw cut-out, which is a measurement method that favors the inferior–central region of the femoral head for placing the lag screw [ 4 , 5 ]. The value of CalTAD appears to be more effectual than the TAD value in predicting the risk of the cut-out in the postoperative period.…”

“…The value of CalTAD appears to be more effectual than the TAD value in predicting the risk of the cut-out in the postoperative period. However, the discrepancy between the two methods is minimal [ 5 ]. In addition, searching the existing literature, no studies demonstrate greater sensitivity and specificity of CalTAD than TAD and vice-versa.…”

“…It is paramount to practice diligent operative techniques to achieve anatomic fracture reduction because proper implant placement cannot be accomplished prior to an anatomic reduction [ 3 ]. TAD and CalTAD values are of great significance concerning the risk for postoperative cut-out [ 4 , 5 ]. Precise intraoperative fracture compression enhances stability and promotes fracture healing, resulting in greater benefits for the patient with early mobilization and full weight-bearing while avoiding the complications of prolonged bed rest [ 2 – 4 ].…”

Cephalomedullary nailing for reverse oblique intertrochanteric fractures 31A3 (AO/OTA)

“…11 Cutting-out of the lag screw is the main complication of proximal femur fracture fixation. 12 The strongest predictor of cutting-out in femoral nailing is tip-apex distance (TAD). 13 Distances less than 25 mm are associated with a significantly decreased risk of slippage of the cephalic screw, 14 while there is a very strong statistical relationship between a TAD greater than 25 mm and mobilization of the cephalic screw.…”