Department of Traumatology, Medical University of Graz, Auenbruggerplatz 7a, 8036, Graz, Austria.
Arch Orthop Trauma Surg. 2011 Nov;131(11):1539-44. doi: 10.1007/s00402-011-1347-9. Epub 2011 Jun 26.
Post-operative knee pain is common following retrograde nailing, with its etiology often multifactorial although a well-established cause is nail protrusion from the intercondylar notch. The aim of this study was to assess the structures at risk if the nail is left proud of the femoral articular surface.
A retrograde femoral nail (Synthes Distal Femoral Nail) was inserted into the distal femur of 15 cadaveric lower limbs using the standard technique. The nail was left 10 mm proud of the articular surface and locked in this position. The knee was then put through a full range of movement while recording the intra-articular structures that came into contact with the distal end of the nail as well as the position of the knee when this occurred. This was repeated with the nail 5 mm proud.
With the nail 10 mm proud, it impinged on the anterior horn of the medial meniscus in 14 cases and the anterior horn of the medial meniscus as well as the tibial insertion of the ACL in one case at 15° of flexion. At 70° of flexion the nail came into contact with the distal margin of the patellar articular surface in the midline in all 15 cases. With the nail 5 mm proud, it impinged on the anterior horn of the medial meniscus in seven cases and the tibial insertion of the ACL as well as the anterior horn of the medial meniscus in eight cases as the knee was brought into full extension. In flexion the distal margin of the patellar articular surface in the midline came into contact with the nail at 70° of flexion in all 15 cases.
Correct positioning of a retrograde femoral nail is of paramount importance to avoid further iatrogenic injury to intra-articular structures.
逆行髓内钉固定后膝关节疼痛常见，其病因通常是多因素的，尽管已经确定一个明确的原因是钉子从髁间切迹突出。本研究的目的是评估如果钉子突出于股骨关节面时哪些结构处于危险之中。
使用标准技术将逆行股骨钉（Synthes 股骨远端钉）插入 15 个尸体下肢的股骨远端。将钉子保留在关节表面上方 10 毫米处并锁定在该位置。然后让膝关节进行全范围运动，同时记录与钉子远端接触的关节内结构以及发生这种情况时膝关节的位置。将钉子保留在 5 毫米处重复此操作。
当钉子突出 10 毫米时，在 14 例中，钉子在 15°屈曲时撞击内侧半月板前角，在 1 例中，钉子撞击内侧半月板前角和 ACL 的胫骨附着处。在所有 15 例中，在 70°屈曲时，钉子在中线接触髌骨关节面的远端边缘。当钉子突出 5 毫米时，在 7 例中，钉子撞击内侧半月板前角，在 8 例中，钉子撞击 ACL 的胫骨附着处和内侧半月板前角，当膝关节完全伸展时。在所有 15 例中，在 70°屈曲时，髌骨关节面的远端边缘在中线与钉子接触。
逆行股骨钉的正确定位对于避免进一步的医源性关节内结构损伤至关重要。
