Patterns of isotope uptake in sequential postoperative bone scan in undisplaced femoral-neck fractures

Abstract

Purpose We aimed to investigate the changing pattern of isotope uptake in the sequential bone scan test for the prediction of osteonecrosis of the femoral head in patients with an undisplaced femoral-neck fracture. Methods Fifty-four cases of sequential bone scan for nondisplaced femoral-neck fracture treated by internal fixation with cannulated screws between 2000 and 2009 were retrospectively studied. The mean follow-up period was 4.2 years. The first postoperative bone scan was performed two weeks postoperatively in all patients. Second, third, and fourth followup bone scans were performed at one to six months, 12-18 months, and 18-24 months postoperatively. Results Mean femoral-head ratio (FHR) in the first postoperative bone scan was 0.99. Although it was under 1.0 in 38 patients (70.4 % of the 54 patients), only one patient developed osteonecrosis of the femoral head. The others showed hot uptake in their second follow-up bone scan. Mean FHRs in the second, third, and fourth postoperative bone scans were 1.69, 1.29, and 1.05, respectively, and there were significant statistical differences in each follow-up period (P=0.035). In addition, there were unique patterns of isotope uptake with the passage of time, such as cold uptake in the early stage, hot uptake in a couple of months, and iso-uptake in the late stage.Conclusions Early postoperative bone scan results should not be over interpreted when predicting osteonecrosis of the femoral head.

Combined Deflection Angle Classification: A Novel Typing System of Adult Femoral Neck Fracture

“…These include studies on non‐union, ankylosis, and avascular necrosis of the femoral head. Studies have shown that the incidence of avascular necrosis after internal fixation using cannulated screws is 45% 21 . Since the complications of FNF often occur within 2 years after surgery, it was practical to choose 2 years as the follow‐up period in this study 23,24 .…”

“…Due to the particularity of the anatomy and physiology of the femoral neck, a variety of complications occur when it is fractured. 21 , 22 These complications have become obstacles in the treatment and rehabilitation of FNF. Currently, there have been several reports on the complications of FNF.…”

“…Studies have shown that the incidence of avascular necrosis after internal fixation using cannulated screws is 45%. 21 Since the complications of FNF often occur within 2 years after surgery, it was practical to choose 2 years as the follow‐up period in this study. 23 , 24 Our research shows that the incidence of complications of FNF is 32.41%, whereas that of avascular necrosis is 25%.…”

Prediction of femoral head avascular necrosis following femoral neck fracture: “pin-tract sign” of99mTc-HDP pinhole bone scan after metallic fixation

“…of the hot uptake of the femoral head in the bone scan is not uniform, but it may be negative at first and positive during the follow-up period. 25,26 This is why it is necessary to supplement it with additional measurements. In this study, the concept of the pin-sign tract was made.…”

Vascular evaluation after cervical hip fractures in children

“…Bone scintigraphy is, however, imprecise and prediction of AVN after fractures in adults with scintigraphy performed 6 weeks after trauma or later proved impossible [27]. Similarly, the pattern of postoperative bone scintigraphy in an undisplaced hip fracture showed considerable variability in a recent study [28]. SPECT is an improvement of planar bone scintigraphy, in which threedimensional information is provided.…”