Proximal Femoral Nail Unlocked versus Locked (ProFNUL): a protocol for a multicentre, parallel-armed randomised controlled trial for the effect of femoral nail mode of lag screw locking and screw configuration in the treatment of intertrochanteric femur fractures

Abstract

IntroductionIntertrochanteric fractures are common fragility injuries in the elderly. Surgical fixation using intramedullary devices are one of the widely used management options. To date, evidence demonstrating the effects of lag screw configuration and the mode of lag screw locking in these devices is lacking. The purpose of this study is to investigate whether the lag screw configuration (single vs integrated dual interlocking screw) and the mode of lag screw locking (static vs dynamic) of a femoral nail device result in differences in clinical and functional outcomes.Methods and analysisA multicentre, pragmatic, single-blinded randomised controlled trial (RCT) with a three-arm parallel group design is proposed. Nine-hundred patients with intertrochanteric fractures (A1 and A2 AO/OTA) will be randomised to fracture treatment using a Gamma3 nail (Stryker; proximally dynamic) or a Trigen Intertan nail (Smith & Nephew) in a dynamic or static lag screw configuration. The primary outcome measure consists of radiological evidence of construct failure within 6 months following surgery, with failure being defined as breakage of the femoral nail or distal locking screw, a change in tip-apex distance of more than 10 mm or lag screw cut-out through the femoral head. Secondary outcomes include surgical data (operation time, fluoroscopy time), complications (surgical site infection, reoperation, patient death), return to mobility and home circumstances, functional independence, function and pain. Patients who are able to walk independently with or without a mobility aid and are able to answer simple questions and follow instructions will be asked to participate in three dimensional gait analysis at 6 weeks and 6 months to assess hip biomechanics from this cohort. Additional secondary measures of gait speed, hip range of motion, joint contact and muscle forces and gross activity monitoring patterns will be obtained in this subgroup.Ethics and disseminationThe Central Adelaide Local Health Network Human Research Ethics Committee has approved the protocol for this RCT (HREC/17/RAH/433). The results will be disseminated via peer-reviewed publications and presentations at relevant conferences.Trial registration numberACTRN12618001431213.

A unique cause of Gamma 3 cut-out: A case report and literature review

“…4 The results of a randomized control trial concerning the dynamic or static lag screw configuration of Gamma 3 nail would be very interesting. 5 Rotation in femoral head-screw unit exists even in cases with proper surgical technique and this has been proven with biomechanical studies. 6,7 Rotation of the head-screw unit may be the mechanism of fixation failure of per trochanteric fractures treated with intramedullary nails, 8 although the exact mechanism has not been adequately investigated so far.…”

“…There is consensus that set screw utilization is obligatory, although recently controversy exists if the sliding effect of the head-screw unit is beneficial. There are studies, 4,5 which support not to unscrew the set screw to avoid the sliding effect, which has been correlated with leg length discrepancy, poorer functional outcomes and cut-out phenomenon. 4 The results of a randomized control trial concerning the dynamic or static lag screw configuration of Gamma 3 nail would be very interesting.…”

Gait biomechanics after proximal femoral nailing of intertrochanteric fractures

“…This prospective study recruited a subset of patients from a large randomized controlled trial treating elderly ITF patients with a femoral nail. 26…”

A rare complication of pelvic perforation by an excessive medial slide of the helical blade after treatment of an intertrochanteric fracture with proximal femoral nail anti-rotation: A case report and literature review

“…However, after the launch of third-generation intramedullary nails, e.g., proximal femoral nail anti-rotation (PFNA), an increasing number of orthopedists prefer them for their superior biological and mechanical advantages. 5 , 6 , 7 , 8 , 9 , 10 PFNA is a commonly used intramedullary fixation device for unstable intertrochanteric fractures, as it has a helical neck blade that provides rotational and angular stability.…”