Orthopaedics and Traumatology Unit, Cattinara Hospital - ASUITS, Strada di Fiume 447, 34149 Trieste (Italy).
Department of Medicine, Surgery and Health Sciences, University of Trieste, Strada di Fiume 447, 34149 Trieste (Italy).
Acta Biomed. 2020 May 30;91(4-S):217-223. doi: 10.23750/abm.v91i4-S.9717.
Understanding the fracture morphology and its relation to the expected outcome and risk of complications is fundamental for proximal humerus fractures (PHFs) management. Most Neer 3- and 4-part fractures may deserve surgical treatment. Unfortunately, plain x-rays may not be able to differentiate between a 3- or 4-part fractures unless an axillary or analogue projection is carried out. Aim of the present study is to evaluate whether a high valgus head-shaft angle degree is predictive of a Neer 4-part rather than a 3-part fracture.
The study included 120 3-(75 cases) and 4-(45 cases) part PHFs (valgus displaced in 98 cases), M:F ratio = 1:2.6, mean age 65.7 years, classified on CT scan images. The humeral head shaft angle was calculated on AP x-rays and statistically correlated with 3 and 4-part fractures to identify values predictive of 4-part fracture.
Valgus head/shaft angle was significantly higher in 4-part fractures, especially in the valgus displaced group (p < 0.001). A cutoff value of 168.5° was identified as predictive of a 4-part fracture with a sensibility of 74% and specificity of 78%. Increasing by 1 degree the humeral head-shaft angle, the chance to have a 4-part fracture increases of 3% in the whole population and of 11% in the valgus sub-group.
The severity of PHF can be predicted analysing valgus head shaft angle on AP x-rays with a sensibility of 74% and specificity of 78% in identifying a 4-part fracture with a cutoff value of 168.5°.
了解骨折形态及其与预期结果和并发症风险的关系是处理肱骨近端骨折（PHF）的基础。大多数 Neer 3 型和 4 型骨折可能需要手术治疗。不幸的是，除非进行腋窝或类似投影，否则普通 X 射线可能无法区分 3 型或 4 型骨折。本研究旨在评估高外展头干角是否可预测 Neer 4 型骨折而不是 3 型骨折。
本研究纳入了 120 例 3 型（75 例）和 4 型（45 例）PHF（98 例为外展移位），男女比例为 1:2.6，平均年龄 65.7 岁，通过 CT 扫描图像进行分类。在前后位 X 射线片上计算肱骨头干角，并与 3 型和 4 型骨折进行统计学相关，以确定预测 4 型骨折的数值。
4 型骨折的外展头干角明显更高，尤其是在外展移位组（p<0.001）。确定 168.5°为预测 4 型骨折的截断值，其敏感性为 74%，特异性为 78%。肱骨头干角每增加 1 度，整个人群发生 4 型骨折的几率增加 3%，在外展亚组增加 11%。
通过分析前后位 X 射线片上的外展头干角，可以预测 PHF 的严重程度，其敏感性为 74%，特异性为 78%，截断值为 168.5°，可识别出 4 型骨折。
