Promsang Trai, Limskul Danaithep, Moonwong Songthai, Kulrat Puchong, Kongrukgreatiyos Kitiphong, Kuptniratsaikul Somsak, Itthipanichpong Thun
Faculty of Medicine, Academic Affair, Chulalongkorn University, Bangkok, Thailand.
Department of Orthopaedics, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, The Thai Red Cross Society, 1873 Rama IV Rd, Pathumwan, Bangkok, 10330, Thailand.
Knee Surg Sports Traumatol Arthrosc. 2023 Jan;31(1):193-198. doi: 10.1007/s00167-022-07041-z. Epub 2022 Jul 6.
Suprascapular nerve (SN) at the spinoglenoid notch is a mobile structure which is vulnerable to iatrogenic injury from screw or guidewire penetration during shoulder surgery such as Latarjet procedure or SLAP/Bankart repairs. The primary objective is to identify the distance between posterior glenoid and SN in different shoulder abduction and rotation. The secondary objective is to identify the distance in standard lateral decubitus position.
Nineteen shoulders from 10 Thiel embalmed soft cadavers were used in this study. The dissection of posterior shoulder was done to identify the SN at spinoglenoid notch. The distance between the posterior glenoid rim and the SN was measured. In beach chair position, the SN distance from six combinations of shoulder position was obtained: adduction/90° internal rotation (ADIR), adduction/neutral rotation (ADN), adduction/90° external rotation (ADER), 45° abduction/90° internal rotation (ABIR), 45° abduction/neutral rotation (ABN), 45° abduction/90° external rotation (ABER). Subsequently, the suprascapular nerve distance was measured in standard lateral decubitus position with 10 lbs. longitudinal traction.
In the beach chair position with the shoulder in adduction, the mean distances between the glenoid and the SN in ADIR, ADN and ADER were 15.0 ± 3.3, 19.3 ± 2.6 and 19.5 ± 3.1 mm, respectively. During shoulder abduction, the mean distances when the shoulder was in ABIR, ABN and ABER were 15.2 ± 3.4, 19.4 ± 3.0 and 19.3 ± 2.6 mm, respectively. The mean distance for the lateral decubitus position was 19.3 ± 2.4 mm. The distance between the glenoid and SN was significantly shorter when the shoulder was positioned in internal rotation than in neutral (p < 0.001) or external rotation (p < 0.001) when compared to the same shoulder abduction position. The lateral decubitus position had comparable SN distance with the shoulder position of abduction/neutral rotation in beach chair position.
The SN was closest to posterior glenoid rim if the shoulder was in internal rotation. Therefore, shoulder internal rotation must be avoided during guidewire and cannulated screw placement in the Latarjet procedure and drill bit insertion during anchor placement in SLAP/Bankart repair.
肩胛上神经（SN）在肩胛冈盂切迹处是一个可移动的结构，在诸如Latarjet手术或SLAP/ Bankart修复等肩部手术过程中，易受螺钉或导丝穿透造成的医源性损伤。主要目的是确定在不同肩部外展和旋转时，肩胛盂后部与SN之间的距离。次要目的是确定标准侧卧位时的距离。
本研究使用了来自10具经蒂尔氏防腐处理的新鲜尸体的19个肩部。对肩部后部进行解剖以识别肩胛冈盂切迹处的SN。测量肩胛盂后缘与SN之间的距离。在沙滩椅位，获得SN在六种肩部位置组合时的距离：内收/90°内旋（ADIR）、内收/中立旋转（ADN）、内收/90°外旋（ADER）、45°外展/90°内旋（ABIR）、45°外展/中立旋转（ABN）、45°外展/90°外旋（ABER）。随后，在标准侧卧位施加10磅纵向牵引力的情况下测量肩胛上神经的距离。
在沙滩椅位且肩部内收时，ADIR、ADN和ADER中肩胛盂与SN之间的平均距离分别为15.0±3.3、19.3±2.6和19.5±3.1毫米。在肩部外展时，肩部处于ABIR、ABN和ABER时的平均距离分别为15.2±3.4、19.4±3.0和19.3±2.6毫米。侧卧位的平均距离为19.3±2.4毫米。与相同肩部外展位置相比，当肩部处于内旋位时，肩胛盂与SN之间的距离明显短于中立位（p<0.001）或外旋位（p<0.001）。侧卧位的SN距离与沙滩椅位外展/中立旋转的肩部位置相当。
如果肩部处于内旋位，SN最靠近肩胛盂后缘。因此，在Latarjet手术中放置导丝和空心螺钉以及在SLAP/Bankart修复中放置锚钉时插入钻头的过程中，必须避免肩部内旋。
