Radiological evaluation of reduction loss in unstable proximal humeral fractures treated with locking plates.
OBJECTIVE
The aim of this study was to radiologically evaluate the risk of reduction loss after locking plate fixation of proximal humerus fractures.


METHODS
From September 2007 to April 2009, 71 patients (28 males, 43 females) with unstable proximal humeral fracture were treated with open reduction and internal fixation by locking plate. The mean follow-up time was 31.2 months (range: 26-47). The head-shaft angulation (HSA) and the humeral head height (HHH) in true anteroposterior (AP) were recorded and compared over time. All complications were noted. Shoulder function was measured by the Constant score.


RESULTS
Patients with ΔHSA >10° (t=2.740, P=0.008) and ΔHHH >5mm (t=2.55, P=0.019) were more likely to have impaired shoulder function. Varus collapse occurred most frequently in patients with initial reduction of HSA <125° (χ(2)=19.17, P<0.001, Fisher's exact test F<0.001). Patients with >5mm HHH decrease were strongly associated with loss of reduction (χ(2)=24.23, P<0.001, F<0.001).


CONCLUSIONS
Dynamic change of HSA >10° and HHH >5mm were radiological factors that indicated poor shoulder function. Intra-operative HSA >125° should be achieved to avoid reduction loss following locking plate fixation of proximal humerus fracture.


METHODS
level IV.
Department of Orthopedics and Traumatology, Peking University People's Hospital, Traffic Medicine Center, XiZhiMen South Avenue 11#, 100044 Beijing, PR China.
L
L
Bai
Department of Orthopedics and Traumatology, Peking University People's Hospital, Traffic Medicine Center, XiZhiMen South Avenue 11#, 100044 Beijing, PR China.
Z-G
ZG
Fu
Department of Orthopedics and Traumatology, Peking University People's Hospital, Traffic Medicine Center, XiZhiMen South Avenue 11#, 100044 Beijing, PR China.
T-B
TB
Wang
Department of Orthopedics and Traumatology, Peking University People's Hospital, Traffic Medicine Center, XiZhiMen South Avenue 11#, 100044 Beijing, PR China.
J-H
JH
Chen
Department of Orthopedics and Traumatology, Peking University People's Hospital, Traffic Medicine Center, XiZhiMen South Avenue 11#, 100044 Beijing, PR China.
P-X
PX
Zhang
Department of Orthopedics and Traumatology, Peking University People's Hospital, Traffic Medicine Center, XiZhiMen South Avenue 11#, 100044 Beijing, PR China. Electronic address: zhangpeixun@bjmu.edu.cn.
D-Y
DY
Zhang
Department of Orthopedics and Traumatology, Peking University People's Hospital, Traffic Medicine Center, XiZhiMen South Avenue 11#, 100044 Beijing, PR China. Electronic address: jiangbaoguo@vip.sina.com.
B-G
BG
Jiang
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001860:Bone Plates; D005260:Female; D005500:Follow-Up Studies; D005593:Fracture Fixation, Internal / Q000295:instrumentation*; D017102:Fracture Healing; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D016059:Range of Motion, Articular; D012189:Retrospective Studies; D012784:Shoulder Fractures / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D012785:Shoulder Joint / Q000000981:diagnostic imaging* / Q000503:physiopathology; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods*; D015599:Trauma Severity Indices
Head-shaft angulation; Humeral head height; Locking plate; Loss of reduction; Proximal humerus fracture; Shoulder function