Risk factors for cut-out in intertrochanteric fractures treated with proximal femoral nail of double proximal screw design.

Background: Intertrochanteric femoral fractures (IFF) are often seen in the elderly after a simple fall because of osteoporosis, and treatment is generally provided with proximal femoral nail (PFN). The complication of cut-out, which can develop as a result of PFN treatment of IFF, is a significant cause of morbidity. The aim of this study was to examine the risk factors for cut-out in cases treated with double proximal screw design nail (DPSDN).

Methods: A retrospective examination was made of patients aged> 70 years, who were operated on for IFF using DPSDN between January 2018 and December 2020. A record was made of the potential risk factors of age, gender, osteoporosis level (Singh Osteoporosis Index), fracture classification (AO/OTA classification), reduction quality, tip-apex distance(calTAD), and proximal screw placement values. Using logistic regression analysis, it was attempted to determine predictive factors for cut-out complication in cases operated on with DPSDN.

Results: With 219 cases included in the study, two groups were formed as cut-out and non-cut-out. Reduction quality, calTAD, and proximal screw placement were seen to be risk factors for cut-out. According to the univariate logistic regression analysis, the cut-out risk was 57.917-fold greater in those with "poor" reduction quality compared to those with "good" reduction quality, the risk was 17-fold greater in those with "superior"screw placement compared to "central" placement (p < 0.001), and 9.24-fold greater in those with "anterior" placement compared to "central" placement (p < 0.001). The cutoff value for calTAD for the diagnosis of cut-out was found to be > 25.5 mm (p = 0.026).

Conclusion: The results of this study demonstrated that the most important risk factors in the use of DPSDN are reduction quality, calTAD and proximal screw placement,. It was also concluded that just as in implants designed with a single screw, there is an increased risk when calTAD is > 25 mm.