Orthopaedics Central, Monash Avenue, Nedlands, Australia.
Barwon Centre of Orthopaedic Research and Education, Deakin University, Geelong, Australia.
Clin Orthop Relat Res. 2021 Oct 1;479(10):2216-2224. doi: 10.1097/CORR.0000000000001869.
There has been decreased use of anatomic total shoulder arthroplasty (aTSA) because reverse TSA (rTSA) is increasingly being used for the same indications. Although short-term studies generally have not found survivorship differences between these implant designs, these studies are often small and their follow-up is limited to the short term. Likewise, the degree to which patient characteristics (such as gender, age, and American Society of Anesthesiologists [ASA] score) may or may not be associated with survivorship differences calls for larger and longer-term studies than is often possible in single-center designs. Large national registry studies may be able to help answer these questions.
QUESTIONS/PURPOSES: By analyzing a large Australian registry series of primary aTSAs with cemented all-polyethylene glenoids and rTSA for osteoarthritis (OA), we asked: (1) Is the revision risk for OA higher for aTSA with all-polyethylene glenoids or for rTSA, adjusting for patient characteristics such as age, gender, ASA score, and BMI? (2) Is the patient's gender associated with differences in the revision risk after controlling for the potentially confounding factors of age, ASA score, and BMI?
In this comparative, observational registry study performed between January 1, 2015, and December 31, 2019, all primary aTSAs with all-polyethylene glenoids and rTSA for OA as determined by the treating surgeon and reported to our national registry formed two groups for analysis. The study period was set to time-match for the collection of ASA score and BMI in 2012 and 2015, respectively. Our registry enrolls more than 97% of all shoulder arthroplasties undertaken in Australia. There were 29,294 primary shoulder arthroplasties; 1592 hemiarthroplasties, 1876 resurfacing and stemless shoulders, 269 stemmed, and 11,674 reverse shoulder arthroplasties were excluded for other diagnoses. A total of 1210 metal-backed glenoids in stemmed aTSA for OA were excluded. A total of 3795 primary aTSAs with all-polyethylene glenoids and 8878 primary rTSAs for OA were compared. An aTSA with an all-polyethylene glenoid and rTSA were more likely to be performed in women (56% and 61% of patients, respectively). The mean age was 69 ± 8 years for aTSA with all-polyethylene glenoids and 74 ± 8 years for rTSA. One aTSA for OA was performed in a patient with an unknown glenoid type. The ASA score (n = 12,438) and BMI (n = 11,233) were also recorded. The maximum follow-up was 5 years for both groups, and the mean follow-up was 2.6 ± 1.4 years for aTSA with all-polyethylene glenoids and 2.1 ± 1.4 years for rTSA. The endpoint was time to revision (all causes), and the cumulative percent revision was determined using Kaplan-Meier estimates of survivorship (time to revision) and HRs from Cox proportional hazard models that were adjusted for age, gender, ASA score, and BMI category.
Overall, there were no differences in the 4-year cumulative percent revision between the groups; the 4-year cumulative percent revision was 3.5% for aTSA with all-polyethylene glenoids (95% CI 2.9%-4.2%) and 3.0% for rTSA (95% CI 2.6%-3.5%). There was an increased risk of revision of rTSA compared with aTSA using all-polyethylene glenoids in the first 3 months (HR 2.17 [95% CI 1.25-3.70]; p = 0.006, adjusted for age, gender, ASA score, and BMI). After that time, there was no difference in the rate of revision, with the same adjustments. In the first 3 months, men undergoing rTSA had a higher rate of revision than men with aTSA using all-polyethylene glenoids (HR 4.0 [95% CI 1.72-9.09]; p = 0.001, adjusted for age, BMI, and ASA). There was no difference between men in the two groups after that time. Women with aTSA using all-polyethylene glenoids were at a greater risk of revision than women with rTSA from 3 months onward (HR 2.77 [95% CI 1.55-4.92]; p < 0.001, adjusted for age, BMI, and ASA), with no difference before that time.
Given the absence of survivorship differences at 4 years between rTSA and aTSA, but in light of the differences in the revision risk between men and women, surgeons might select an aTSA with an all-polyethylene glenoid to treat OA, despite the current popularity of rTSA. However, there are survivorship differences between genders. Future studies should evaluate whether our comparative findings are replicated in men and women undergoing aTSA with all-polyethylene glenoids and rTSA for primary diagnoses such as rheumatoid arthritis or post-traumatic arthritis, and whether there are functional differences between the two implant designs when used for OA.
Level III, therapeutic study.
由于越来越多的医生选择使用反向全肩关节置换术（rTSA）来治疗相同的疾病，解剖型全肩关节置换术（aTSA）的应用有所减少。尽管短期研究通常未发现这两种植入物设计之间存在生存率差异，但这些研究通常规模较小，随访时间也仅限于短期。同样，患者特征（如性别、年龄和美国麻醉师协会[ASA]评分）是否与生存率差异相关，这需要更大规模和更长时间的研究，而这在单中心设计中往往是不可能的。大型国家注册研究可能有助于回答这些问题。
问题/目的：通过分析澳大利亚大型原发性 aTSA 与骨水泥固定的全聚乙烯盂肱关节和 rTSA 治疗骨关节炎（OA）的注册系列研究，我们提出以下问题：（1）在调整了患者年龄、性别、ASA 评分和 BMI 等特征后，对于 OA，全聚乙烯盂肱关节的 aTSA 或 rTSA 的翻修风险更高？（2）在控制了年龄、ASA 评分和 BMI 等潜在混杂因素后，患者的性别是否与翻修风险的差异有关？
在这项比较性、观察性的注册研究中，我们纳入了 2015 年 1 月 1 日至 2019 年 12 月 31 日期间澳大利亚所有原发性 aTSA，这些患者均因治疗医生的诊断而行 aTSA 治疗，且报告给我们的国家注册系统。该研究的时间设定为与 2012 年和 2015 年收集 ASA 评分和 BMI 相匹配。我们的注册系统涵盖了澳大利亚所有肩关节炎置换手术的 97%以上。共有 29294 例初次肩关节置换术，其中 1592 例为半肩置换术、1876 例为表面置换和无柄肩置换术、269 例为带柄肩置换术和 11674 例 rTSA，其他诊断为其他疾病。共有 1210 例使用金属背衬的聚乙烯盂肱关节的 aTSA 因其他诊断而被排除。共有 3795 例原发性 aTSA 与全聚乙烯盂肱关节和 8878 例原发性 rTSA 用于 OA 治疗。在 aTSA 与 rTSA 中，使用全聚乙烯盂肱关节的患者更有可能为女性（分别为 56%和 61%的患者）。aTSA 与全聚乙烯盂肱关节的平均年龄为 69±8 岁，rTSA 的平均年龄为 74±8 岁。有 1 例 OA 患者的盂肱关节类型未知。记录了 ASA 评分（n=12438）和 BMI（n=11233）。两组的最大随访时间均为 5 年，aTSA 与全聚乙烯盂肱关节的平均随访时间为 2.6±1.4 年，rTSA 的平均随访时间为 2.1±1.4 年。终点是所有原因的翻修时间，通过 Kaplan-Meier 估计生存时间（翻修时间）和 Cox 比例风险模型的 HR 来确定累积翻修百分比，该模型调整了年龄、性别、ASA 评分和 BMI 类别。
总体而言，两组在 4 年时的累积翻修百分比无差异；aTSA 与全聚乙烯盂肱关节的 4 年累积翻修百分比为 3.5%（95%CI 2.9%-4.2%），rTSA 为 3.0%（95%CI 2.6%-3.5%）。在最初的 3 个月内，rTSA 的翻修风险高于 aTSA 与全聚乙烯盂肱关节（HR 2.17 [95%CI 1.25-3.70]；p=0.006，调整了年龄、性别、ASA 评分和 BMI）。此后，在同样的调整下，翻修率没有差异。在最初的 3 个月内，接受 rTSA 的男性比接受 aTSA 与全聚乙烯盂肱关节的男性翻修率更高（HR 4.0 [95%CI 1.72-9.09]；p=0.001，调整了年龄、BMI 和 ASA）。此后，两组男性之间没有差异。从 3 个月开始，接受 aTSA 与全聚乙烯盂肱关节的女性比接受 rTSA 的女性翻修风险更高（HR 2.77 [95%CI 1.55-4.92]；p<0.001，调整了年龄、BMI 和 ASA），在此之前没有差异。
鉴于 rTSA 和 aTSA 在 4 年时的生存率没有差异，但考虑到男性和女性之间翻修风险的差异，尽管 rTSA 目前很流行，外科医生可能会选择 aTSA 与全聚乙烯盂肱关节来治疗 OA。然而，性别之间存在生存差异。未来的研究应评估我们在原发性诊断（如类风湿关节炎或创伤后关节炎）中使用 aTSA 与全聚乙烯盂肱关节和 rTSA 的比较发现是否在男性和女性中得到复制，以及在使用 OA 时两种植入物设计是否存在功能差异。
III 级，治疗性研究。
