Fluoroscopic Marker-Based Guidance System Improves Gamma Lag Screw Placement During Nailing of Intertrochanteric Fractures: A Randomized Controlled Trial.

Objectives: To determine whether a fluoroscopy-based navigation system would improve tip-apex distance (TAD) compared with the conventional technique.

Design: Randomized controlled trial.

Setting: Level 1 trauma center.

Patients: A total of 161 patients were screened for inclusion in the study. After meeting inclusion and exclusion criteria, 31 patients were randomized (n = 18 navigated vs. n = 13 control group), with the patient blinded to the result.

Intervention: Fluoroscopy-based navigated guidance of lag screw length and position.

Main Outcome Measures: Average TAD and the proportion of TAD over 25 mm.

Results: TAD was lower in the navigated group compared with the control group (mean = 17.5 vs. 24.2 mm; P = 0.0018). No navigated cases exceeded the 25 mm TAD threshold, compared with 39% of conventional cases (P = 0.0076). Navigation resulted in fewer drilling attempts compared with the conventional technique (median = 1 vs. 4 attempts; P < 0.0001). We detected no significant differences in operation time or total number of fluoroscopic images (P > 0.05).

Conclusions: Fluoroscopy-based computer navigated Gamma nailing for intertrochanteric fractures improved TAD and reduced the number of drilling attempts without increasing operation time compared with the conventional fluoroscopy-guided technique in a teaching hospital setting.

Level Of Evidence: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.