Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, Milan, Italy.
Azienda Ospedaliera "Sant'Anna", Como, Italy.
Arthroscopy. 2014 Feb;30(2):165-71. doi: 10.1016/j.arthro.2013.09.082. Epub 2013 Dec 17.
To evaluate, using magnetic resonance (MR), the biological efficacy of anchors made of 30% β-tricalcium phosphate and 70% poly-lactic co-glycolide (PLGA) used for the repair of Bankart lesions after shoulder instability.
Twenty consecutive patients who were candidates for surgical treatment for unidirectional, post-traumatic shoulder instability were treated arthroscopically with anchors made of 70% PLGA plus 30% β-tricalcium phosphate preloaded with OrthoCord suture (DePuy Mitek, Raynham, MA). Fifteen of them were evaluated by MR at least 16 months after the intervention. A second evaluation was performed at least 12 months after the first evaluation in the patients in whom implanted anchors were still visible at the first evaluation (n = 5) with a low-intensity signal in all sequences. Two radiologists, with different amounts of experience (15 and 3 years), separately evaluated the MR patterns of the trabecular glenoid bone, the walls of the bone tunnel, and the signal from the anchors. The following parameters were considered in the MR evaluation: integrity of the tunnel edge (grade 0 to 2), intensity of the signal from the anchor site (grade 1 to 3), and presence of cystic lesions. The normal signal from the glenoid trabecular bone has been used as the reference parameter. The anchors were considered independent variables, and thus each one was analyzed individually, even in the same patient. At the final clinical follow-up, a Rowe questionnaire was filled out for each patient.
Overall, 44 anchors were evaluated (33 anchors at the first follow-up and 11 anchors at the second follow-up). The mean follow-up period was 28.6 months. With the exception of 2 patients (10%), none of the patients had any episodes of dislocation, having satisfactory postoperative results. No cystic lesions were detected by MR imaging. The interobserver concordance between the 2 radiologists calculated with the Cohen κ was substantial (κ = 0.780 and κ = 0.791 for integrity of tunnel edge and for intensity of signal from anchor site, respectively). Both the integrity of the tunnel border and the intensity of the signal at the site of the anchors that had been implanted more than 24 months before the evaluation were significantly different from those of anchors implanted less than 24 months before the evaluation (tunnel border grade of 0 in 41%, 1 in 50%, and 2 in 9% v 0 in 4.5%, 1 in 50%, and 2 in 45.5% [P = .003]; anchor signal grade of 1 in 41%, 2 in 45.5%, and 3 in 13.5% v 1 in 13.5%, 2 in 41%, and 3 in 45.5% [P = .03]). Analysis of the linear contrasts (analysis of variance) showed a linear increase in the mean values for time to increased tunnel border grade (grade 0, 22 ± 4 months; grade 1, 27 ± 8 months; and grade 2, 29 ± 5 months [P = .02]) and grade of intensity of the signal in the anchor site (grade 1, 24 ± 6 months; grade 2, 26 ± 7 months; and grade 3, 29 ± 7 months [P = .05]).
Anchors made of 30% β-tricalcium phosphate and 70% PLGA showed excellent biological efficacy, without causing significant cystic lesions, producing gradual changes in the MR signal that seems to become equivalent to that of the glenoid trabecular bone at a mean of 29 months after implantation.
Level IV, therapeutic case series.
使用磁共振（MR）评估用于修复肩不稳 Bankart 损伤的 30%β-磷酸三钙和 70%聚乳酸共乙醇酸（PLGA）制成的锚钉的生物学疗效。
连续 20 例单向创伤性肩不稳患者接受关节镜下治疗，使用预载 OrthoCord 缝线的 70%PLGA 加 30%β-磷酸三钙制成的锚钉（DePuy Mitek，Raynham，MA）。其中 15 例至少在干预后 16 个月接受了 MR 评估。在第一次评估时仍可见植入锚钉且所有序列均呈低信号的患者（n=5）中，至少在第一次评估后 12 个月进行了第二次评估。两位放射科医生（经验分别为 15 年和 3 年）分别单独评估了关节盂骨小梁的 MR 模式、骨隧道壁和锚钉的信号。MR 评估考虑了以下参数：隧道边缘的完整性（0 级至 2 级）、锚钉部位信号的强度（1 级至 3 级）和囊性病变的存在。参考参数为正常关节盂骨小梁信号。将锚钉视为自变量，因此即使在同一位患者中，也会单独分析每个锚钉。在最终临床随访时，每位患者都填写了 Rowe 问卷。
总共评估了 44 个锚钉（第一次随访时 33 个，第二次随访时 11 个）。平均随访时间为 28.6 个月。除 2 例患者（10%）外，所有患者均无脱位发作，术后结果满意。MR 成像未发现囊性病变。2 位放射科医生之间的观察者间一致性通过 Cohen κ 计算为中等（隧道边缘完整性和锚钉部位信号强度的 κ 值分别为 0.780 和 0.791）。与植入前 24 个月相比，隧道边缘的完整性和植入时间超过 24 个月的锚钉部位信号强度均有显著差异（0 级的隧道边缘分级为 41%、50%和 9%，1 级为 4.5%、50%和 45.5%，2 级为 45.5%[P=.003]；锚钉信号分级为 1 级的 41%、45.5%和 13.5%，2 级为 13.5%、41%和 45.5%，3 级为 45.5%[P=.03]）。线性对比（方差分析）分析显示，隧道边缘分级的平均时间呈线性增加（0 级，22±4 个月；1 级，27±8 个月；2 级，29±5 个月[P=.02]），锚钉部位信号强度的分级也呈线性增加（1 级，24±6 个月；2 级，26±7 个月；3 级，29±7 个月[P=.05]）。
由 30%β-磷酸三钙和 70%PLGA 制成的锚钉具有优异的生物学疗效，不会引起明显的囊性病变，在植入后平均 29 个月时，MR 信号会逐渐发生变化，似乎与关节盂骨小梁的信号相当。
IV 级，治疗性病例系列。
