Occult Intertrochanteric Extension in Isolated Greater Trochanteric Fracture on Plain Radiographs

Full Article

WY Wong, PY Chu, WCS Chan, TW Yeung, MK Yuen

Hong Kong J Radiol 2016;19:28-34

DOI: 10.12809/hkjr1615331

Objectives: To review the prevalence of occult intertrochanteric extension and fracture pattern in patients with isolated greater trochanteric (GT) fracture on plain radiographs.

Methods: Between January 2010 and December 2013, patients with trochanteric hip fracture at a regional hospital in Hong Kong were retrospectively reviewed. Those with isolated GT fracture on plain radiographs were included. The demographic details, premorbid condition, computed tomography (CT) findings, fracture pattern, surgical intervention, outcome, and follow-up radiographs were analysed.

Results: Of 928 patients with trochanteric fracture, 58 (6.3%) showed isolated GT fracture on plain radiographs. CT was performed in 51 (87.9%) patients: 10 (17.2%) had intertrochanteric extension, and 7 of them were offered operative fixation. Dynamic hip screw was inserted in five, and surgery was avoided in two who were considered having a high anaesthetic risk. For the fracture pattern of greater trochanter on CT, 29 (56.9%) showed more than one facet involvement. Most involved the superoposterior facet (39/51, 76.5%), followed by anterior facet (25/51, 49.0%), lateral facet (15/51, 29.4%), and posterior facet (12/51, 23.5%). In the intertrochanteric extension group, there was a higher proportion of anterior facet involvement (Fisher’s exact test, p = 0.038; odds ratio = 5.65 [95% confidence interval, 1.06-30.0]) and lower proportion of superoposterior facet involvement (p = 0.042; odds ratio = 0.21 [95% confidence interval, 0.047-0.91]). There was no statistically significant difference in the posterior and lateral facet involvement, or the age and gender in both groups.

Conclusion: In patients with isolated GT fracture on plain radiographs, 17% showed intertrochanteric extension on CT scans. Prompt and meticulous search for intertrochanteric extension is mandatory, particularly when CT scan reveals anterior facet involvement.