UNASSIGNED: Consecutive patients who underwent primary anatomic total shoulder arthroplasty from a single-surgeon practice were enrolled. All patients received a preoperative computed tomography (CT) scan for surgical templating purposes. The exclusion criteria were lack of a preoperative CT scan, preoperative plan for a stemmed component, and intraoperative conversion to a stem for a reason other than bone quality (ie, fracture). Preoperative CT scans were analyzed with an automated templating software. Cortical index and thickness were calculated, and bone density of the proximal diaphysis, cancellous metaphysis, and cortical metaphysis was obtained by averaging Hounsfield units (HU) across anatomically defined regions using a previously validated technique. The decision to convert to a stemmed humeral component was made intraoperatively based on a lack of stability of the trial stemless component. Bone quality measurements were compared between stemless and stemmed groups. An exact logistic regression was used incorporating gender and age.
UNASSIGNED: A total of 79 patients who underwent primary anatomic total shoulder arthroplasty were included in this study. Of these patients, 6 underwent intraoperative conversion to a stemmed humeral component (7.6%). There was no significant difference between cohorts in terms of cortical index and bone density within the proximal diaphysis and cortical metaphysis. On univariate analysis, cortical thickness, metaphyseal cancellous bone density, and gender were significantly different between groups. Patients receiving a stem had significantly lower metaphyseal cancellous bone density than those receiving stemless components (5.5 ± 11.2 HU vs. 47.6 ± 29.4 HU, P<.001). All patients converted to stems were female individuals (P = .01) and had metaphyseal cancellous bone density less than 20 HU (P<.001).
UNASSIGNED: Metaphyseal cancellous bone density can be calculated on preoperative CT scans and is associated with intraoperative conversion to a stemmed humeral component in anatomic shoulder arthroplasty. A threshold of 20 HU can be used to predict which patients are more likely to require stemmed components.
■连续纳入单外科医生行初次解剖全肩关节置换术的患者。所有患者均接受术前计算机断层扫描(CT)扫描以进行手术模板。排除标准是术前缺乏CT扫描,有茎的组件的术前计划,术中由于骨骼质量以外的原因转换为茎(即,骨折)。使用自动化模板软件分析术前CT扫描。计算皮质指数和厚度,和近端骨干的骨密度,松质干phy端,使用先前验证的技术,通过在解剖学上定义的区域平均Hounsfield单位(HU)来获得皮质干his端。基于试验无茎组件缺乏稳定性,术中决定转换为有茎的肱骨组件。比较无茎组和茎组之间的骨质量测量值。使用包含性别和年龄的精确逻辑回归。
■本研究共纳入79例初次解剖全肩关节置换术患者。在这些病人中,6例接受术中转换为有茎的肱骨组件(7.6%)。在近端骨干和皮质干meta端内的皮质指数和骨密度方面,队列之间没有显着差异。在单变量分析中,皮质厚度,干phy端松质骨密度,两组间性别差异显著。接受茎的患者的干phy端松质骨密度明显低于接受无茎成分的患者(5.5±11.2HUvs.47.6±29.4HU,P<.001)。所有转化为茎的患者均为女性(P=.01),干phy端松质骨密度小于20HU(P<.001)。
■干骨干端松质骨密度可通过术前CT扫描计算,并与解剖肩关节成形术术中转换为有柄的肱骨成分有关。20HU的阈值可用于预测哪些患者更可能需要茎状部成分。