Comparison of tip apex distance and cut-out complications between helical blades and lag screws in intertrochanteric fractures among the elderly: a meta-analysis

To investigate whether helical blade implant systems have advantages in terms of tip apex distance (TAD) and cut-out rate in comparison to conventional lag screws for intertrochanteric fractures in a geriatric population. Relevant articles were sourced from the MEDLINE, Embase, Ovid and Cochrane Library databases from inception through March 2015. All randomized controlled trials (RCTs) comparing outcomes between helical blade and lag screw implant systems were selected. Mean TAD values and reported cut-out complications were noted. Each author independently assessed the relevance of the enrolled studies and the quality of the extracted data. Data were analyzed using R software. Ten studies including 1831 patients were eligible for this review, seven of which were included in a combined analysis of dichotomous outcomes and five in a combined analysis of continuous outcomes. The results revealed that, compared with lag screw implantations, the use of helical blades led to a lower rate of cut-out complications (95 % CI: 0.28-0.96, P = 0.036). Patients who experienced cut-out complications had a significantly greater tip apex distance (95 % CI: 0.68-1.34, P < 0.001). However, the actual tip apex distances were similar between the screw group and blade group (95 % CI: -0.44-0.79, P = 0.58). No difference in TAD values was found between blades and screws. In addition, the cut-out risk in the blade-design group was lower than that of the screw group. Therefore, TAD is not an accurate predictor of cut-out risk.