Dixit Nikhil N, McCormick Carolyn M, Cole Jacqueline H, Saul Katherine R
Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC.
Joint Department of Biomedical Engineering, University of North Carolina, Chapel Hill, NC; North Carolina State University, Raleigh, NC.
J Hand Surg Am. 2021 Jun;46(6):512.e1-512.e9. doi: 10.1016/j.jhsa.2020.10.019. Epub 2020 Dec 25.
Patient presentation after brachial plexus birth injury (BPBI) is influenced by nerve injury location; more contracture and bone deformity occur at the shoulder in postganglionic injuries. Although bone deformity after postganglionic injury is well-characterized, the extent of glenohumeral deformity after preganglionic BPBI is unclear.
Twenty Sprague-Dawley rat pups received preganglionic or postganglionic neurectomy on a single forelimb at postnatal days 3 to 4. Glenohumeral joints on affected and unaffected sides were analyzed using micro-computed tomography scans after death at 8 weeks after birth. Glenoid version, glenoid inclination, glenoid and humeral head radius of curvature, and humeral head thickness and width were measured bilaterally.
The glenoid was significantly more declined in affected compared with unaffected shoulders after postganglionic (-17.7° ± 16.9°) but not preganglionic injury. Compared with the preganglionic group, the affected shoulder in the postganglionic group exhibited significantly greater declination and increased glenoid radius of curvature. In contrast, the humeral head was only affected after preganglionic but not postganglionic injury, with a significantly smaller humeral head radius of curvature (-0.2 ± 0.2 mm), thickness (-0.2 ± 0.3 mm), and width (-0.3 ± 0.4 mm) on the affected side compared with the unaffected side; changes in these metrics were significantly associated with each other.
These findings suggest that glenoid deformities occur after postganglionic BPBI but not after preganglionic BPBI, whereas the humeral head is smaller after preganglionic injury, possibly suggesting an overall decreased biological growth rate in this group.
This study expands understanding of the altered glenoid and humeral head morphologies after preganglionic BPBI and its comparisons with morphologies after postganglionic BPBI.
臂丛神经产伤（BPBI）后的患者表现受神经损伤部位影响；节后损伤时肩部出现更多挛缩和骨畸形。尽管节后损伤后的骨畸形特征明显，但节前BPBI后盂肱关节畸形的程度尚不清楚。
20只Sprague-Dawley大鼠幼崽在出生后第3至4天接受单前肢节前或节后神经切除术。出生8周后死亡时，使用微型计算机断层扫描对患侧和未患侧的盂肱关节进行分析。双侧测量关节盂倾斜度、关节盂倾角、关节盂和肱骨头曲率半径以及肱骨头厚度和宽度。
节后损伤（-17.7°±16.9°）后患侧关节盂比未患侧明显更倾斜，但节前损伤后无此情况。与节前组相比，节后组患侧肩部的倾斜度明显更大，关节盂曲率半径增加。相比之下，肱骨头仅在节前损伤后受到影响，患侧肱骨头曲率半径（-0.2±0.2mm）、厚度（-0.2±0.3mm）和宽度（-0.3±0.4mm）明显小于未患侧；这些指标的变化彼此显著相关。
这些发现表明，节后BPBI后会出现关节盂畸形，而节前BPBI后不会出现，而节前损伤后肱骨头较小，这可能表明该组的整体生物生长速率下降。
本研究扩展了对节前BPBI后关节盂和肱骨头形态改变及其与节后BPBI形态比较的理解。
