Early postoperative three-phase Technetium-99 m bone scanning predicts traumatic osteonecrosis in patients with femoral neck fractures: a 2- to 6-year follow-up study

Introduction

This study aimed to explore the predictive value of early postoperative TPBS on post-traumatic osteonecrosis of the femoral head (ONFH) in femoral neck fracture (FNF) patients after internal fixation.

Materials and methods

This study retrospectively reviewed the FNF patients who underwent TPBS within 72 h after internal fixation from January 2017 to December 2020 in our institution. All Patients were divided into ONFH and non-ONFH groups during the follow-up, and diagnostic analysis was used to assess the predictive value of TPBS on ONFH occurrence.

Results

Fifty-one patients (51 hips) were included, with a mean follow-up of 4.7 years, ranging from 2.3 to 6.7 years. Twenty-one out of 51 patients showed femoral head perfusion defects on the postoperative TPBS, and 15 of the 21 patients developed ONFH in the follow-up. The sensitivity, specificity, positive predictive value, and negative predictive value of TPBS are 93.75%, 83.33%, 71.43%, and 96.77%, respectively. The semi-quantitative analyses showed that the tracer uptake in the lateral and medial pillars of the femoral head in the ONFH group was significantly reduced compared with the contralateral side. In contrast, the uptake in the medial, central, and lateral columns of the fracture side in the non-ONFH group was significantly higher than those on the contralateral side.

Conclusions

The present results found that early postoperative TPBS showed high sensitivity and specificity in predicting posttraumatic ONFH for the FNF patients after internal fixation and has considerable value in estimating the future risk of ONFH.