Predictors of Cut-Out after Fixation of Intertrochanteric Fractures with Two Cephalocervical Screwed Proximal Femur Nails

Abstract

Objective: To identify the factors of predicting cut-out development about implant position after fixation of proximal femoral fractures with two cephalocervical screwed femoral nails and to calculate the position-related failure risk. Methods: Retrospective analysis of clinical and radiographic data were performed on hospital records and 20 cases with implant cut-out were included in the study group. 31 cases from a similar epidemiological group who completed the second year without failure were included as a control group. Tip-apex distance (TADAP-TADL), calcar tip apex distance (CalTAD) were measured using radiographs, and Parker ratio was calculated for anteroposterior (ParkerAP) and lateral (ParkerLat) views. Advanced analysis was performed for each statistically significant variable to determine the cut-off point of the predictors for implant cut-out. Results: TADAP-L (p:<0.001), CalTAD (p:0.001) and ParkerLat ratio (p:0.001) calculated were found to have prognostic significance to estimate implant cutout. ParkerLat was found to be the most significant to estimate implant cut-out (p:0.001). The risk of implant cut-out development increased by 7.3 fold in TADAP, 5.7 in TADLat, and 8.6 in CalTAD, and the greatest risk was calculated in ParkerLat, and this increase was 11.5 fold (Cut-off:≥0.58, p:<0,001) Conclusion: Current study confirmed the significant relationship between implant cut-out and inadequate TAD and ParkerLat. The importance of predictors identified to prevent the development of this phenomenon has been demonstrated in this study for two cephalocervical screwed proximal femur nails. It has been shown that the central positioning of the proximal screw inserted while providing osteosynthesis in both anterior-posterior and lateral views was important in preventing cut-out development.