Abstract：
BACKGROUND: The purpose of this study was to compare the medium-term results for anatomic total shoulder arthroplasty by humeral component stem length. We hypothesize that the newer stemless implants may have comparable results to short-stem and conventional stemmed implants.
METHODS: The 12 most used anatomic total shoulder arthroplasty implants on the New Zealand Joint Registry were included in the study. Implants were categorized by stem length-conventional, short, and stemless. The primary outcome was revision up to 7 years postsurgery. Secondary outcomes included revision cause, implant survival, and early functional outcomes as evaluated by the Oxford Shoulder Score. Analysis was stratified by age and surgeon volume to control for potential confounding.
RESULTS: A total of 3952 patients (conventional, 3114; short, 360; stemless, 478) were included in the study. No significant difference in revision rate per 100 component-years was found between stemless, short-stem, and conventional stemmed implants (revision rate per 100 component-years: conventional, 1.01 [95% confidence interval (CI) 0.89-1.14]; short, 0.54 [95% CI 0.25-1.03]; stemless, 0.99 [95% CI 0.51-1.74]). This finding was irrespective of patient age or surgeon volume. There were no cases of humeral loosening up to 7 years\' follow-up and no cases of intraoperative humeral fracture in the stemless group. Functional outcomes at 6 months postsurgery suggested better outcomes in the stemless group compared with the conventional stem group (mean Oxford Shoulder Score: conventional, 39.4; stemless, 40.7; P value = .023).
CONCLUSIONS: The medium-term survival of stemless implants for anatomic total shoulder arthroplasty appears comparable to short-stem and conventional stemmed implants. Further follow-up is required to understand the long-term survivorship and functional outcomes between these groups.
METHODS: The 12 most used anatomic total shoulder arthroplasty implants on the New Zealand Joint Registry were included in the study. Implants were categorized by stem length-conventional, short, and stemless. The primary outcome was revision up to 7 years postsurgery. Secondary outcomes included revision cause, implant survival, and early functional outcomes as evaluated by the Oxford Shoulder Score. Analysis was stratified by age and surgeon volume to control for potential confounding.
RESULTS: A total of 3952 patients (conventional, 3114; short, 360; stemless, 478) were included in the study. No significant difference in revision rate per 100 component-years was found between stemless, short-stem, and conventional stemmed implants (revision rate per 100 component-years: conventional, 1.01 [95% confidence interval (CI) 0.89-1.14]; short, 0.54 [95% CI 0.25-1.03]; stemless, 0.99 [95% CI 0.51-1.74]). This finding was irrespective of patient age or surgeon volume. There were no cases of humeral loosening up to 7 years\' follow-up and no cases of intraoperative humeral fracture in the stemless group. Functional outcomes at 6 months postsurgery suggested better outcomes in the stemless group compared with the conventional stem group (mean Oxford Shoulder Score: conventional, 39.4; stemless, 40.7; P value = .023).
CONCLUSIONS: The medium-term survival of stemless implants for anatomic total shoulder arthroplasty appears comparable to short-stem and conventional stemmed implants. Further follow-up is required to understand the long-term survivorship and functional outcomes between these groups.
摘要：
背景：这项研究的目的是比较解剖全肩关节成形术的中期结果通过肱骨组件茎长度。我们假设较新的无茎植入物可能具有与短茎和常规茎植入物相当的结果。
方法：本研究纳入了新西兰关节登记处最常用的12种解剖全肩关节置换术植入物。植入物按常规茎长度分类，短,和无茎。主要结果是术后7年的修正。次要结果包括修订原因，植入物存活，以及通过牛津肩评分评估的早期功能结果。根据年龄和外科医生容量对分析进行分层，以控制潜在的混杂因素。
结果：共3952例患者（常规，3114；短，360；无茎，478）被纳入研究。每100个组件年的修订率没有发现显著差异，短茎，和传统的茎状植入物(每100个组件年的翻修率：传统，1.01[95%置信区间(CI)0.89-1.14]；短，0.54[95%CI0.25-1.03]；无茎，0.99[95%CI0.51-1.74]）。这一发现与患者年龄或外科医生体积无关。随访7年，无茎组无肱骨松动病例，术中无肱骨骨折病例。术后6个月的功能结局表明，无茎组的结局优于常规茎组（平均牛津肩评分：常规，39.4；无茎，40.7；P值=.023）。
结论：用于解剖全肩关节置换术的无茎植入物的中期生存率似乎与短茎植入物和常规茎植入物相当。需要进一步的随访以了解这些群体之间的长期生存和功能结果。
方法：本研究纳入了新西兰关节登记处最常用的12种解剖全肩关节置换术植入物。
结果：共3952例患者（常规，
结论：用于解剖全肩关节置换术的无茎植入物的中期生存率似乎与短茎植入物和常规茎植入物相当。
