Orthopaedics Department, Phramongkutklao Hospital, 315 Ratchvidhi Road, Thung Phaya Thai, Ratchathewee, Bangkok, 10400, Thailand.
Department of Orthopaedic Surgery, Queen Sirikit Naval Hospital, Phlu Ta Luang, Thailand.
J Orthop Surg Res. 2022 Jan 4;17(1):6. doi: 10.1186/s13018-021-02892-7.
Proximal humeral fracture is the third most common of osteoporotic fracture. Most surgical cases were treated by fixation with anatomical locking plate system. The calcar screw plays a role in medial support and improving varus stability. Proximal humerus fracture in elderly patients are commonly seen with greater tuberosity (GT) fracture. The GT fragment is sometimes difficult to use as an anatomic landmark for proper plate and screw position. Therefore, the insertion of pectoralis major tendon (PMT) may be used as an alternative landmark for appropriate plate and calcar screw position. The purpose of study is going to identify the vertical distance from PMT to a definite point on the position of locking plate.
30 cadaveric shoulders at the department of clinical anatomy were performed. Shoulders with osteoarthritic change (n = 5) were excluded. Finally, 25 soft cadaveric shoulders were recruited in this study. The PHILOS™ plate was placed 2 mm posterior to the bicipital groove. A humeral head (HH) was cut in the coronal plane at the level of the anterior border of the PHILOS plate with a saw. A calcar screw was inserted close to the inferior cortex of HH. Distance from the upper border of elongated combi-hole (UB-ECH) to the upper border of pectoralis major tendon (UB-PMT) was measured. The plate was then moved superiorly until the calcar screw was 12 mm superior to the inferior border of HH and the distance was repeatedly measured.
The range of distance from UB-PMT to the UB-ECH was from - 4.50 ± 7.95 mm to 6.62 ± 7.53 mm, when calcar screw was close to inferior border of HH and when the calcar screw was 12 mm superior to the inferior border of HH, respectively. The highest probability of calcar screw in proper location was 72% when UB-ECH was 3 mm above UB-PMT.
The GT fragment is sometimes difficult to use as an anatomic landmark for proper plate and screw position. PMT can be used as an alternative anatomic reference. UB-PMT can serve as a guide for proper calcar screw insertion. UB-ECH should be 3 mm above UB-PMT and three-fourths of cases achieved proper calcar screw location.
肱骨近端骨折是骨质疏松性骨折中第三常见的骨折。大多数手术病例采用解剖锁定钢板系统固定。肩峰螺钉在提供内侧支撑和改善内翻稳定性方面发挥作用。老年患者的肱骨近端骨折常伴有大结节（GT）骨折。GT 骨折块有时难以用作正确钢板和螺钉位置的解剖标志。因此，胸大肌腱（PMT）的插入可以作为适当钢板和肩峰螺钉位置的替代解剖标志。本研究的目的是确定从 PMT 到锁定钢板位置的某一点的垂直距离。
在临床解剖学系进行了 30 个尸体肩部实验。排除了伴有骨关节炎改变的肩部（n=5）。最终，本研究共招募了 25 个柔软的尸体肩部。PHILOS™钢板放置在肱二头肌沟后 2mm 处。用锯在冠状面于 PHILOS 钢板前缘水平处切割肱骨头（HH）。插入靠近 HH 下皮质的肩峰螺钉。测量加长组合孔（UB-ECH）上缘到胸大肌腱（UB-PMT）上缘的距离。然后将钢板向上移动，直到肩峰螺钉位于 HH 下边界上方 12mm，重复测量距离。
当肩峰螺钉靠近 HH 下边界时，UB-PMT 到 UB-ECH 的距离范围为-4.50±7.95mm 至 6.62±7.53mm；当肩峰螺钉位于 HH 下边界上方 12mm 时，距离范围为-4.50±7.95mm 至 6.62±7.53mm。当 UB-ECH 比 UB-PMT 高 3mm 时，正确定位肩峰螺钉的概率最高为 72%。
GT 骨折块有时难以用作正确钢板和螺钉位置的解剖标志。PMT 可作为替代解剖参考。UB-PMT 可作为正确插入肩峰螺钉的指南。UB-ECH 应比 UB-PMT 高 3mm，四分之三的病例可实现正确的肩峰螺钉定位。
