Association between lateral femoral wall thickness and BMD with the occurrence of lateral wall fracture in DHS fixation.

Background: Nearly 50% of all hip fractures are intertrochanteric fractures (ITF) and are linked to osteopenia and advancing age. For secure ITF repair, the dynamic hip screw (DHS) fixation is regarded gold standard surgery. However, controversy exists regarding the use of DHS in the treatment of unstable ITF especially in patients with pre-operative lateral femoral wall fracture (LWF). The purpose of this study is to find if there's a link between lateral femoral wall thickness, bone mineral density and the risk of LWF in DHS fixation.

Patient And Methods: A prospective, observational cohort analysis of 70 consecutive patients with ITF was undertaken in a tertiary care government hospital. All patients were treated with a 135° DHS fixation under regional anaesthesia and fluoroscopic guidance. Lateral femoral wall thickness was assessed pre-operatively on radiographs and during surgery. Mean T score as a measure of bone mineral density was recorded in all patients.

Result: Postoperative LWFs occurred in 11 individuals. In 11 patients who had a postoperative LWF, the mean lateral femoral wall thickness was 19.545 mm, while the remaining 54 patients had a mean lateral femoral wall thickness of 29.285 mm (P < 0.001) With 81.5% sensitivity, the lateral femoral wall thickness threshold that could predict LWF was determined to be less than 25 mm. The mean T score of the contralateral hip in LWF patients was -2.255 standard deviation, whereas it was -2.428 standard deviation in patients without LWF, the difference of which was statistically not significant.

Conclusion: DHS fixation alone should be avoided in ITF patients with lateral femoral wall thickness <25 mm and other implant choices should be explored for management of these patients.