Orthopaedic Department, Qilu Hospital of Shandong University, No. 107 Wenhua West Road, Jinan, 250012, China.
Sci Rep. 2021 Sep 20;11(1):18596. doi: 10.1038/s41598-021-98040-6.
We hypothesized that postoperative malrotation of humeral shaft fractures can alter the bio-mechanical environment of the shoulder; thus, rotator cuff and cartilage degeneration could be induced. Therefore, we designed an animal experiment to evaluate the impact of malrotation deformities after minimally invasive surgery for humeral fractures on the rotator cuff and cartilage, which has rarely been described in previous studies. Twenty-four New Zealand white rabbits were randomly divided into the sham control group (A), negative control group (B) and malrotated group (C). A sham operation with surgical exposure alone was performed in group A. Humeral shaft osteotomy was performed in Group B and C. In Group B, the fractures were fixed in situ with plate -screw system. While in Group C, iatrogenic rotational deformity was created after the proximal end of the fracture being internally rotated by 20 degrees and then subsequently fixed. The animals with bone healing were sacrificed for pathological and biochemical examination. In group C, the modified Mankin scale for cartilage pathology evaluation and the modified Movin scale for tendon both showed highest score among groups with statistical significance (P < 0.05); Disordered alignment and proportion of collagen I/III of rotator cuff were confirmed with picrosirius red staining; Transmission electron microscopy also showed ultrastructural tendon damage. Immunohistochemistry showed that both MMP-1 and MMP-13 expression were significantly higher in group C than groups A and B(P < 0.05). Minimally invasive techniques for humerus shaft fracture might be cosmetically advantageous, but the consequent postoperative malrotation could increase the risk of rotator cuff and cartilage degeneration. This conclusion is supported here by primary evidence from animal experiments.
我们假设肱骨骨折术后的旋转畸形可能改变肩部的生物力学环境，从而导致肩袖和软骨退变。因此，我们设计了一项动物实验来评估微创治疗肱骨骨折后旋转畸形对肩袖和软骨的影响，这在以前的研究中很少有描述。24 只新西兰大白兔被随机分为假手术对照组（A 组）、阴性对照组（B 组）和旋转畸形组（C 组）。A 组仅行手术暴露的假手术。B 组和 C 组行肱骨干骨折切开复位。B 组采用钢板螺钉系统固定骨折，C 组在骨折近端内旋 20 度后造成医源性旋转畸形，然后再固定。骨愈合后，对动物进行病理和生化检查。C 组的改良 Mankin 软骨病理评分和改良 Movin 肌腱评分均显著高于其他两组（P<0.05）；旋转红染色证实肩袖胶原 I/III 排列紊乱和比例失调；透射电镜也显示了肌腱的超微结构损伤。免疫组化显示，C 组的 MMP-1 和 MMP-13 表达均明显高于 A 组和 B 组（P<0.05）。微创技术治疗肱骨干骨折可能具有美容优势，但随之而来的术后旋转畸形可能会增加肩袖和软骨退变的风险。这一结论得到了动物实验的初步证据支持。
