Pain Therapy, Department of Anaesthesiology, Kantonsspital Lucerne, Lucerne, Switzerland.
Division of Anaesthesia, Balgrist University Hospital, Forchstrasse 340, 8008, Zurich, Switzerland.
Eur J Orthop Surg Traumatol. 2024 Aug;34(6):3339-3347. doi: 10.1007/s00590-024-04057-8. Epub 2024 Aug 21.
The radial nerve may be painfully irritated or damaged by open reduction and internal fixation (ORIF) of humeral fractures. Secondary radial nerve lesions after ORIF of humeral shaft fractures are described in up to 16%. Not only peripheral nerves but also orthopaedic instruments and osteosynthesis material are well visible by ultrasound. The aim of this study was to evaluate the accuracy of ultrasound in assessing the relation between the bone overlapping screw tips and the radial nerve close to the humeral bone.
Ultrasound-guided drilling was used to place screws as close as possible to the radial nerve in 8 humeral bones of four cadavers. The relation between the radial nerve and the screw tips was assessed by high-resolution ultrasound, and the overlap of all screw tips over the bone was measured by ultrasound and fluoroscopy. Thereafter, the findings were validated by anatomical dissection.
We could correctly identify all screw tips and their relation to the radial nerve by ultrasound. In 7 of 8 cases, the screw tip had direct contact with the radial nerve. The overlaying length of the screw tip was accurately measured by using ultrasound in all cases. In contrast fluoroscopy underestimated this length in 50% of cases.
With this study, we show that ultrasound can reliable visualize the screw tips and its relation to the radial nerve. Ultrasound is a promising diagnostic tool to evaluate patients with radial nerve irritations or lesions after ORIF of humeral fractures. Furthermore, ultrasound could be an adequate tool to guide drilling.
肱骨骨折切开复位内固定（ORIF）可能会引起桡神经疼痛或损伤。肱骨骨干骨折 ORIF 后，继发性桡神经损伤的发生率高达 16%。不仅周围神经，骨科器械和内固定材料在超声下也清晰可见。本研究旨在评估超声评估骨重叠螺钉尖端与肱骨附近桡神经之间关系的准确性。
在 4 具尸体的 8 个肱骨上，使用超声引导下钻孔将螺钉尽可能靠近桡神经放置。通过高分辨率超声评估桡神经与螺钉尖端的关系，并通过超声和透视测量所有螺钉尖端在骨上的重叠长度。然后通过解剖验证这些发现。
我们可以通过超声正确识别所有螺钉尖端及其与桡神经的关系。在 8 例中有 7 例，螺钉尖端与桡神经直接接触。在所有病例中，均通过超声准确测量了螺钉尖端的重叠长度。相比之下，透视在 50%的病例中低估了该长度。
通过本研究，我们表明超声可以可靠地显示螺钉尖端及其与桡神经的关系。超声是评估肱骨骨折 ORIF 后桡神经刺激或损伤患者的有前途的诊断工具。此外，超声可以作为引导钻孔的有效工具。
