Catalano Louis W, Crivello Keith, Lafer Marissa Purcelli, Chia Benjamin, Barron O Alton, Glickel Steven Z
C.V. Starr Hand Surgery Center, St. Luke’s-Roosevelt Hospital, 1000 Tenth Ave., 3rd Floor, New York, NY 10019, USA.
J Hand Surg Am. 2011 Oct;36(10):1659-62. doi: 10.1016/j.jhsa.2011.07.001. Epub 2011 Aug 23.
Displaced olecranon fractures are often amenable to treatment with open reduction and tension-band wiring. The purpose of this study is to examine the relationships of the tips of K-wires used in a tension-band construct to volar neurovascular structures in the proximal forearm and the proximal radioulnar joint.
We performed simulated percutaneous pinnings of the proximal ulna under fluoroscopic guidance on 15 cadavers with intact proximal ulnas. The K-wires were drilled obliquely through the tip of the olecranon process and directed to engage the anterior ulnar cortex, distal to the coronoid. Using calipers, we measured the distance from the tip of each pin to the anterior interosseous nerve (AIN), ulnar artery, proximal radioulnar joint (PRUJ), and volar cortex of the ulna, as well as the distance from the volar cortex of the ulna to the AIN and ulnar artery. The angle created by the K-wires and the longitudinal axis of the ulna was measured on both anteroposterior and lateral radiographs.
The distance from pin tip to the AIN and ulnar artery measured a mean of 16 mm with a standard deviation of 6 mm and 14 mm with a standard deviation of 5 mm, respectively, with 1 pin abutting the artery. The shortest distance from both the AIN (11 ± 5 mm) and the ulnar artery (8 ± 6 mm) was measured with the shallowest angle of insertion, ranging from 10° to 14.9° on lateral radiographs. The mean distance between the pin tip and the PRUJ measured 7 mm with a standard deviation of 4 mm, with 3 pins penetrating the PRUJ.
The impaction of K-wires under the triceps is often approximately 1 cm, which is similar to the distance of the K-wire tips to the AIN and ulnar artery. Our findings suggest that larger insertion angles might help avoid neurovascular injury when the insertion point of the K-wires is at or just proximal to the tip of the olecranon. In this study, the safe zone for pin insertion on the anteroposterior view is 0° to 10°, and on the lateral view it is 20° to 30°.
This anatomic study was done to diminish the chance of complications resulting from K-wire placement during tension-band wiring for olecranon fractures.
移位的鹰嘴骨折通常适合采用切开复位张力带钢丝固定治疗。本研究的目的是探讨张力带结构中克氏针尖端与前臂近端掌侧神经血管结构以及近端桡尺关节之间的关系。
我们在15具近端尺骨完整的尸体上，在透视引导下对近端尺骨进行模拟经皮穿针。克氏针经鹰嘴突尖端斜向钻入，指向尺骨冠状突远端的前尺骨皮质。我们用卡尺测量每根针尖端到骨间前神经（AIN）、尺动脉、近端桡尺关节（PRUJ）和尺骨掌侧皮质的距离，以及尺骨掌侧皮质到AIN和尺动脉的距离。在前后位和侧位X线片上测量克氏针与尺骨纵轴形成的角度。
针尖端到AIN和尺动脉的距离平均分别为16mm（标准差6mm）和14mm（标准差5mm），有1根针紧邻动脉。在侧位X线片上，插入角度最浅（10°至14.9°）时，测量到的AIN（11±5mm）和尺动脉（8±6mm）的最短距离。针尖端与PRUJ之间的平均距离为7mm（标准差4mm），有3根针穿透PRUJ。
三头肌下克氏针的打入深度通常约为1cm，这与克氏针尖端到AIN和尺动脉的距离相似。我们的研究结果表明，当克氏针的插入点在鹰嘴尖端或其近端时，较大的插入角度可能有助于避免神经血管损伤。在本研究中，前后位X线片上克氏针插入的安全区为0°至10°，侧位X线片上为20°至30°。
进行这项解剖学研究是为了减少鹰嘴骨折张力带钢丝固定过程中克氏针放置导致并发症的几率。
