Design innovation and rationale of the intramedullary implants for treating Intertrochanteric fractures: A review

Intertrochanteric fracture management require effective management strategies for early return to function and minimise complications. Intramedullary devices like proximal femoral nail have an biomechanical advantage, particularly in unstable intertrochanteric fractures. Such unstable injury patterns not only require precise reduction technique, but also right implant design to minimise the complications. Novel concepts of reduction like medial cortical support classification and antero-posterior reduction (Subtype classification system) refine the reduction strategies. Despite reporting of the reduction analysis, there has been continuing number of implant failures following proximal femoral nail implantation. Complications like 'Z' effect and reverse 'Z' effect are very well reported with the 2 screw Recon - Proximal femur nails. Analysis of failure and complications have constantly upgraded the designs of proximal femur nails. Design of the new generation intramedullary implants for treatment of intertrochanteric fractures like Gamma nail, PFNA-II (Proximal Femoral Nail Anterotation), Zimmer Natural Nail, Trigen Intertan nail and TFN - Advanced (Trochanteric Femoral Nail Advanced) are described in this review. While the new implant designs offer advancements, fundamental principles of reduction remains crucial for successful outcomes. Design rationale and instrumentation of each implant must be known at the time of application along with techniques of maintaining the reduction for a successful outcome.