Nijs Stefaan, Sermon An, Broos Paul
Department of Trauma Surgery, UZ Leuven, Herestraat 49, 3000 Leuven, Belgium.
Patient Saf Surg. 2008 Dec 16;2(1):33. doi: 10.1186/1754-9493-2-33.
Proximal humerus fractures are one of the most common fractures. Intramedullary locked nailing is becoming a popular alternative treatment, especially for easier fracture patterns. Although axillary nerve injury has been reported, no study has compared the safety of the proximal locking options relative to the axillary nerve and the ascending branch of the anterior circumflex artery.
Six different commercially available proximal humeral nails were implanted in 30 shoulders of 18 cadavers. After fluoroscopically guided implantation the shoulders were carefully dissected and the distance between the locking screws, the axillary nerve and the ascending branch of the anterior circumflex artery was measured.
The course of the axillary nerve varies. A mean distance of 55.8 mm (SD = 5.3) between the lateral edge of the acromions and the axillary nerve at the middle of the humerus in a neutrally rotated position was observed. The minimum distance was 43.4 mm, the maximum 63.9 mm.Bent nails with oblique head interlocking bolts appeared to be the most dangerous in relation to the axillary nerve. The two designs featuring such a bend and oblique bolt showed a mean distance of the locking screw to the axillary nerve of 1 mm and 2.7 mm respectively Sirus (Zimmer(R)) and (Stryker(R)) T2 PHN (Proximal Humeral Nail)).Regarding the ascending branch of the anterior circumflex artery, there was no difference between the nails which have an anteroposterior locking option.
It is of great importance for surgeons treating proximal humerus fractures to understand the relative risk of any procedure they perform. Since the designs of different nailing systems risk damaging the axillary nerve and ascending branch, blunt dissection, the use of protection sleeves during drilling and screw insertion, and individual risk evaluation prior to the use of a proximal humeral nail are advocated.
肱骨近端骨折是最常见的骨折之一。髓内锁定钉固定正成为一种流行的替代治疗方法，尤其适用于较简单的骨折类型。尽管已有腋神经损伤的报道，但尚无研究比较近端锁定方式相对于腋神经和旋肱前动脉升支的安全性。
将六种不同的市售肱骨近端钉植入18具尸体的30个肩部。在透视引导下植入后，仔细解剖肩部并测量锁定螺钉、腋神经和旋肱前动脉升支之间的距离。
腋神经走行各异。在中立旋转位时，观察到肩峰外侧缘与肱骨中部腋神经之间的平均距离为55.8 mm（标准差=5.3）。最小距离为43.4 mm，最大距离为63.9 mm。带有斜头互锁螺栓的弯钉相对于腋神经似乎最危险。具有这种弯曲和斜螺栓的两种设计显示锁定螺钉到腋神经的平均距离分别为1 mm（西鲁斯（捷迈公司））和2.7 mm（史赛克公司的T2 PHN（近端肱骨钉））。关于旋肱前动脉升支，具有前后锁定选项的钉子之间没有差异。
对于治疗肱骨近端骨折的外科医生来说，了解他们所进行的任何手术的相对风险非常重要。由于不同钉系统的设计有损伤腋神经和升支的风险，因此提倡钝性解剖、在钻孔和拧入螺钉时使用保护套以及在使用肱骨近端钉之前进行个体风险评估。
