# Femoral malrotation after trochanteric fracture nailing: what is the safety zone of limb rotation during closed reduction?

## TL;DR

This study identifies a safe rotation range during hip fracture surgery to prevent dangerous femoral malrotation.

## Contribution

The study quantifies a 20° rotation threshold as a risk factor for significant postoperative femoral malrotation.

## Key findings

- 33.3% of patients experienced femoral malrotation exceeding 15° after surgery.
- Limb rotation exceeding 20° on the traction table increased malrotation risk to 51%.
- Internal rotation was significantly more common than external rotation in malposition cases.

## Abstract

Improper closed trochanteric fracture reduction can cause rotational malposition which can lead to serious consequences. The primary objective of this study was to assess the hypothetical threshold at which excessive rotation becomes hazardous due to a significant postoperative malrotation.

We conducted a prospective study focused on closed reduction in intramedullary nailing of trochanteric fractures (AO 31A1-3) in 100 consecutive patients and its influence on final malrotation. Immediately after the closed reduction, the rotation of affected limb was measured using a balanced goniometer and the values were compared to the postoperative CT calculation. Final femoral malrotation exceeding 15° was considered significant. All results were statistically analyzed.

In total we observed femoral malrotation exceeding 15° in 33 patients (33.3%). Internal rotation was significantly more common than external rotation (31 vs. 2 patients). Intraoperative rotation up to 15° resulted in a malrotation of 10.3% (3/29 patients). When limb rotation on the traction table exceeded 20°, malrotation incidence increased to 51.0% (26/51 patients), making this fixed position a risk factor for significant femoral malrotation (p = 0.0076). General anesthesia was also associated with a significantly higher rate of malrotation compared to spinal anesthesia (p = 0.0154), however we did not find any statistical difference in error rates based on patient BMI or physiological femoral neck ante-version.

Our findings underscore the significant risk of femoral malrotation associated with perioperative rotations beyond 20°, emphasizing the need for precise rotational control during surgery. Excessive rotation on the traction table in an attempt to achieve better fracture alignment significantly increases the risk of femoral malrotation.