Factors associated with mechanical complications in intertrochanteric fracture treated with proximal femoral nail antirotation

Abstract

Purpose: Although proximal femoral nail antirotation (PFNA; Synthes, Switzerland) has demonstrated satisfactory results when used for the treatment of intertrochanteric fractures, mechanical complications may occur. To better quantify the risk of mechanical complications when proximal femoral nail antirotation is used to treat intertrochanteric fractures, this study aimed to: (1) characterize the frequency of mechanical complications and extent of blade sliding and their correlation with reduction quality and (2) identify factors associated with mechanical complications. Materials and Methods: A review of medical records from 93 patients treated for intertrochanteric fractures with a minimum of 6-months of follow-up between February 2014 and February 2019 was conducted. Blade position was evaluated using Tip-apex distance (TAD) and Cleveland index. The extent of blade sliding was evaluated using the adjusted Doppelt’s method for intramedullary nailing. Individuals were classified as having or not having mechanical complications, and reduction quality and radiologic outcomes were compared between the two groups. Results: Mechanical complications occurred in 12 of 94 hips (12.8%), with 11 out of 12 being from the intramedullary reduction group. There was no significant difference in TAD between groups; however, there were significant differences were noted in Cleveland index, AO/OTA classification, reduction quality and extent of blade sliding. The mean blade sliding distance was 1.17 mm (anatomical group), 3.28 mm (extramedullary group), and 6.11 mm (intramedullary group), respectively (P<0.001). Data revealed that blade sliding was an associated factor for mechanical complications (odds ratio 1.25, 95% confidence interval 1.03-1.51). Conclusion: The extent of blade sliding determined using the adjusted Doppelt’s method was significantly associated with mechanical complications suggesting that prevention of excessive sliding through proper intraopera-tive reduction is important to help achieve satisfactory treatment outcomes.