Jia Xiao-Yang, Chen Yan-Xi, Qiang Min-Fei, Zhang Kun, Li Hao-Bo, Jiang Yu-Chen, Zhang Yi-Jie
Department of Orthopaedic Trauma, East Hospital, Tongji University School of Medicine, Shanghai, China.
Orthop Surg. 2017 May;9(2):167-173. doi: 10.1111/os.12332. Epub 2017 May 30.
To compare postoperative CT images with plain radiographs for measuring prognostic factors of reduction loss of fractures of the proximal part of the humerus.
A total of 65 patients who sustained fractures of the proximal humerus treated with locking plates from June 2012 to October 2015 were retrospectively analyzed. There were 24 men and 41 women, with a mean age of 60.0 years (range, 22-76 years). According to the Neer classification system of proximal humeral fracture, there were 26 two-part, 27 three-part and 12 four-part fractures of the proximal part of the humerus, and all fractures were treated with open reduction and internal fixation (ORIF) using locked plating. All postoperative CT images and plain radiographs of the patients were obtained. Prognostic factors of the reduction loss were the change of neck shaft angle (NSA) and the change of humeral head height (HHH). The change of NSA and HHH were evaluated by the difference between postoperative initial and final follow-up measurement. Reduction loss was defined as the change ≥10° for NSA or ≥5 mm for HHH. The NSA and HHH were measured using plain radiographs and 3-D CT images, both initially and at final follow-up. The paired t-test was used for comparison of NSA, change of NSA, HHH, and change of HHH between two image modalities. The differences between two image modalities in the assessment of reduction loss were examined using the χ -test (McNemar test). Intraclass correlation coefficients (ICC) were used to assess the intra-observer and inter-observer reliability.
3-D CT images (ICC range, 0.834-0.967) were more reliable in all parameters when compared with plain radiographs (ICC range, 0.598-0.915). Significant differences were found between the two image modalities in all parameters (plain radiographs: initial NSA = 133.6° ± 3.8°, final NSA = 130.0° ± 1.9°, initial HHH = 17.9 ± 0.9 mm, final HHH = 15.8 ± 1.5 mm; 3-D CT: initial NSA = 131.4° ± 3.4°, final NSA = 128.8° ± 1.7°, initial HHH = 16.8 ± 1.2 mm, final HHH = 14.5 ± 1.1 mm; all P < 0.05). In the assessment of reduction loss, the percentage was 16.9% (11/65) for the plain radiographs and 7.7% (5/65) for the 3-D CT scans (P < 0.05). For the 5 patients with reduction loss, which were observed by two imaging modalities, the mean Constant-Murley score was 61.0 ± 1.6. The patients with reduction loss, observed only in plain radiographs but not CT images, had good shoulder function (Constant-Murley score: 82.7 ± 1.0).
Our data reveal that 3-D CT images are more reliable than plain radiographs in the assessment of the prognostic factors of reduction loss of fractures of the proximal part of the humerus with treatment of locking plates; this reliable CT technique can serve as an effective guideline for the subsequent clinical management of patients.
比较术后CT图像与X线平片在测量肱骨近端骨折复位丢失预后因素方面的差异。
回顾性分析2012年6月至2015年10月期间采用锁定钢板治疗的65例肱骨近端骨折患者。其中男性24例，女性41例，平均年龄60.0岁（范围22 - 76岁）。根据肱骨近端骨折的Neer分类系统，肱骨近端两部分骨折26例，三部分骨折27例，四部分骨折12例，所有骨折均采用切开复位锁定钢板内固定（ORIF）治疗。获取所有患者术后的CT图像和X线平片。复位丢失的预后因素为颈干角（NSA）的变化和肱骨头高度（HHH）的变化。NSA和HHH的变化通过术后初始和最终随访测量的差值进行评估。复位丢失定义为NSA变化≥10°或HHH变化≥5 mm。初始和最终随访时均使用X线平片和三维CT图像测量NSA和HHH。采用配对t检验比较两种影像检查方式下NSA、NSA变化值、HHH及HHH变化值。采用χ²检验（McNemar检验）检查两种影像检查方式在评估复位丢失方面的差异。组内相关系数（ICC）用于评估观察者内和观察者间的可靠性。
与X线平片（ICC范围0.598 - 0.915）相比，三维CT图像在所有参数方面（ICC范围0.834 - 0.967）更可靠。两种影像检查方式在所有参数上均存在显著差异（X线平片：初始NSA = 平均133.6°±3.8°，最终NSA = 平均130.0°±1.9°，初始HHH = 平均17.9±0.9 mm，最终HHH = 平均15.8±1.5 mm；三维CT：初始NSA = 平均131.4°±3.4°，最终NSA = 平均128.8°±1.7°，初始HHH = 平均16.8±1.2 mm，最终HHH = 平均14.5±1.1 mm；所有P < 0.05）。在评估复位丢失方面，X线平片的比例为16.9%（11/65），三维CT扫描为7.7%（5/65）（P < 0.05）。对于两种影像检查方式均观察到复位丢失的5例患者，Constant - Murley平均评分为61.0±1.6。仅在X线平片中观察到复位丢失而CT图像未观察到的患者，肩部功能良好（Constant - Murley评分：82.7±1.0）。
我们的数据表明，在评估锁定钢板治疗的肱骨近端骨折复位丢失的预后因素方面，三维CT图像比X线平片更可靠；这种可靠的CT技术可为后续患者的临床管理提供有效的指导。
