Background:

All-suture anchors are increasingly being used in rotator cuff repair. However, there are debates on the micromotion of all-suture anchors.

Purpose:

To perform rotator cuff repair on patients with rotator cuff tears and different shoulder bone mineral densities (BMDs) and investigate (1) where the anchor is located under the cortex, (2) if there is any anchor migration settling during follow-up, and (3) if structural outcome differs according to shoulder BMD.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

We retrospectively investigated 88 patients who underwent arthroscopic single-row repair for small- to medium-sized rotator cuff tears (age [mean ± SD], 58.8 ± 7.1 years) from 712 cases of rotator cuff tendon repair between November 2015 and February 2018. Inclusion criteria were as follows: use of an all-suture anchor; preoperative shoulder BMD; and magnetic resonance imaging (MRI) conducted preoperatively, 2 days after surgery, and 10 months after surgery. Patients were excluded from the study if they underwent open rotator cuff repair (n = 118), got surgery with a double-row technique (n = 178), underwent surgery with anchors other than the all-suture type (n = 273), received anchor insertion in sites other than the greater tuberosity owing to concomitant procedures such as biceps tenodesis and subscapularis repair (n = 29), did not take preoperative shoulder BMD (n = 15), had more than a large-size tear (n = 6), and were lost to follow-up (n = 5). After compression of the all-suture anchor during surgery, the strands were pulled multiple times to ensure that the anchor was fixed onto the bone with appropriate tension. BMD was measured before surgery. Depth to anchor (DA), anchor settling, and repaired rotator cuff integrity were measured with MRI. Patients were categorized into 3 groups: group A (BMD, <0.4 g/cm²; n = 31), group B (BMD, 0.4-0.6 g/cm²; n = 32), and group C (BMD, >0.6 g/cm²; n = 25). A total of 65 patients had follow-up MRI. On the basis of rotator cuff tendon integrity, patients were categorized into either a sufficient thickness group (group S, Sugaya classification grade II or lower; n = 44) or an insufficient thickness group (group I, Sugaya classification grade III or higher; n = 21).

Results:

On time-zero MRI, the DA differed significantly among groups (group A, 3.62 ± 2.02 mm; group B, 5.18 ± 2.13 mm; group C, 6.30 ± 3.34 mm) (P = .001). The DA was deeper in patients with a higher BMD at time zero (r = 0.374; P = .001), but the DA did not differ at follow-up MRI (mean, 10.3 months after surgery). On follow-up MRI, anchor settling tended to increase with deeper time-zero DA (r = 0.769; P < .001). Anchor settling was significantly different among groups (group A, 1.33 ± 1.08 mm; group B, 2.78 ± 1.99 mm; group C, 3.81 ± 2.19 mm) (P = .001). The proportion of patients with sufficient thickness in each group did not show a statistical difference (group A, 70.8%; group B, 72.7%; group C, 57.9%) (P = .550).

Conclusion:

In conclusion, this study confirmed that the postoperative site of anchor insertion in arthroscopic single-row rotator cuff repair with all-suture anchors was located farther from the cortex in patients with higher shoulder BMD and closer to the subcortical bone in patients with lower BMD. On follow-up MRI, no further settling occurred past a certain distance from the cortex, and there was no significant difference in anchor depth or integrity of the rotator cuff tendon based on shoulder BMD. Therefore, minimal settling in the all-suture anchor did not show clinical significance.

中文翻译：

---

关节镜修复中小型旋转袖套眼泪后的全缝合锚定置。

背景：

全缝合锚越来越多地用于肩袖修复中。但是，关于全缝合锚的微动有争论。

目的：

对患有肩袖撕裂和不同肩骨矿物质密度（BMD）的患者进行肩袖修复，并调查（1）锚位于皮层下的位置；（2）随访期间是否有任何锚定迁移沉降；以及（3）如果结构结果根据肩部BMD而有所不同。

学习规划：

队列研究；证据水平3。

方法：

我们回顾性研究了2015年11月至2018年2月间712例肩袖肌腱修补术的88例经关节镜行单行修复的中小型肩袖撕裂症（年龄[平均±SD]，58.8±7.1岁）。纳入标准如下：使用全缝合锚钉；术前肩部骨密度；术前，术后2天和术后10个月进行磁共振成像（MRI）。如果患者接受了开放式肩袖修补术（n = 118），采用双排技术进行了手术（n = 178），使用了非全缝合类型的锚钉（n = 273）进行了手术，则被排除在研究之外，由于伴随二头肌腱扩张术和肩s下肌修复术（n = 29），在大结节以外的部位接受了锚钉插入，术前未接受肩部BMD（n = 15），超过大面积撕裂（n = 6）以及无法进行随访（n = 5）。在手术过程中压缩全缝合锚钉后，将股线多次拉出，以确保锚钉以适当的张力固定在骨骼上。术前测量骨密度。使用MRI测量锚定深度（DA），锚定沉降和修复的肩袖完整性。患者分为三组：A组（BMD，<0.4 g / cm MRI检查修复的肩袖完整性。患者分为三组：A组（BMD，<0.4 g / cm MRI检查修复的肩袖完整性。患者分为三组：A组（BMD，<0.4 g / cm² ; n = 31），B组（BMD，0.4-0.6 g / cm ²； n = 32）和C组（BMD，> 0.6 g / cm ²； n = 25）。共有65例患者接受了MRI随访。根据肩袖肌腱完整性，将患者分为足够的厚度组（S组，Sugaya分类等级为II或更低； n = 44）或厚度不足的组（I组，Sugaya分类等级为III或更高； n = 21）。

结果：

在零时MRI上，各组之间的DA差异显着（A组为3.62±2.02 mm； B组为5.18±2.13 mm； C组为6.30±3.34 mm）（P = .001）。在零时点BMD较高的患者，DA较深（r = 0.374；P = .001），但在后续MRI检查中（平均，手术后10.3个月），DA没有差异。在后续的MRI检查中，锚定点趋于随着零时差DA的增加而增大（r = 0.769；P <.001）。各组之间的锚定沉降差异显着（A组为1.33±1.08 mm; B组为2.78±1.99 mm; C组为3.81±2.19 mm）（P= .001）。各组中具有足够厚度的患者比例没有统计学差异（A组为70.8％； B组为72.7％； C组为57.9％）（P = .550）。

结论：

总之，这项研究证实，在使用全缝合锚钉的关节镜单行肩袖修复中，锚钉插入的术后位置距肩高BMD的患者离皮质较远，而距骨密度低的患者更靠近皮质下骨。在后续的MRI检查中，在距皮质一定距离处没有进一步的沉降，并且基于肩部BMD的锚固深度或肩袖肌腱的完整性也没有显着差异。因此，在全缝合锚中的最小沉降没有显示出临床意义。