Navigation-assisted implantation of Gamma3 nails – What are the benefits of the ADAPT system?

Introduction: Optimal placement of the femoral neck screw is essential during osteosynthesis of pertrochanteric fractures. A low tip-apex distance (TAD) is crucial to avoid a cut-out of the femoral neck screw. Whether the use of a navigation system during osteosynthesis with Gamma3 nails positively influences the TAD, fluoroscopy time and surgery duration has been assessed differently in the initial clinical applications. We tested the ADAPT system for positioning Gamma3 nails as part of a standardised laboratory experiment. Methods: An inexperienced surgeon and an experienced surgeon each implanted 20 Gamma3 nails in artificial bones. Each surgeon performed 10 conventional interventions and 10 using the ADAPT system. Subsequently, TAD, femoral neck screw positioning, fluoroscopy time, number of X-ray images and surgery duration were compared. The experimental set-up also assessed whether the ADAPT system offers advantages over distal freehand locking for long Gamma3 nails. Results: The inexperienced surgeon was able to implant the nail significantly faster when using the ADAPT system (99.10 s/60.20 s; p = 0.005), while the experienced surgeon required more time to implant the femoral neck screws (59.70 s/94.00 s, p < 0.001). The fluoroscopy times of both surgeons were somewhat shorter when using the ADAPT system. All femoral neck screws were placed correctly with a TAD of less than 20 mm. Only the TAD of the inexperienced surgeon was reduced with the use of the ADAPT system (16.30 mm/12.40 mm; p < 0.001). Conclusions: The ADAPT system could reduce TAD and possibly fluoroscopy time, especially in inexperienced surgeons. For experienced surgeons, there was no influence on TAD and only a minimal effect on fluoroscopy time.