, Volume 10, Issue 2, pp 59-61,
Open Access This content is freely available online to anyone, anywhere at any time.
Date: 13 Mar 2009

The importance of surgical education in the accuracy of implant placement during hip fracture fixation



Studies have found that tip apex distance (TAD) is the strongest independent predictor of lag screw cut-out following hip fracture fixation. The objective of this study was to understand the importance of introducing the concept of TAD to surgeons. The null hypothesis was that there were no differences between fractures fixed before awareness of TAD compared with fractures fixed after awareness of TAD.

Materials and Methods

This study involved assessing 75 consecutive radiographs retrospectively (before introduction of “tip apex distance” to surgeons) and 83 consecutive radiographs prospectively (after introduction of “tip apex distance” to surgeons). Radiographs were measured using a radiograph digitizer and software.


Average TAD in radiographs measured retrospectively was 22.6 mm compared with 9.7 mm in radiographs analysed prospectively (P ≤ 0.001). The power of this study was 97%.


This study demonstrates that introducing the concept of “TAD” to surgeons, will improve the accuracy of lag screw placement during fixation of an extracapsular fracture. The improvements in lag screw placement will undoubted reduce cut-out of the implant post-surgery.

This study was supervised by the late Professor Harper, Professor of Orthopaedic Surgery at the University of Leicester, who sadly died in 2008. Our thoughts are with him.