Department of Orthopaedic Surgery, Orthopedic and Rheumatologic Institute, Cleveland Clinic, Cleveland, OH, USA.
Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA.
J Shoulder Elbow Surg. 2021 Feb;30(2):237-249. doi: 10.1016/j.jse.2020.07.033. Epub 2020 Aug 7.
The purpose of this study was to quantify correction of glenoid deformity and humeral head alignment in anatomic total shoulder arthroplasty as a function of preoperative pathology (modified Walch classification) and glenoid implant type in a clinical cohort using 3-dimensional computed tomography (CT) analysis.
Patients undergoing anatomic total shoulder arthroplasty with a standard glenoid (SG) (n = 110) or posteriorly stepped augmented glenoid (AG) (n = 62) component were evaluated with a preoperative CT scan and a postoperative CT scan within 3 months of surgery. Glenoid version, inclination, and medial-lateral (ML) joint line position, as well as humeral head alignment, were assessed on both CT scans, with preoperative-to-postoperative changes analyzed relative to pathology and premorbid anatomy based on the modified Walch classification and glenoid implant type.
On average, correction to the premorbid ML joint line position was significantly less in type A2 glenoids than in type A1 glenoids (-2.3 ± 2.1 mm vs. 1.1 ± 0.9 mm, P < .001). Correction to premorbid version was not different between type B2 glenoids with AG components and type A1 glenoids with SG components (-1.7° ± 6.6° vs. -1.0° ± 4.0°, P = .57), and the premorbid ML joint line position was restored on average in both groups (0.3 ± 1.6 mm vs. 1.1 ± 0.9 mm, P = .006). Correction to premorbid version was not different between type B3 glenoids with AG components and type A1 glenoids with SG components (-0.6° ± 5.1° vs. -1.0° ± 4.0°, P = .72), but correction relative to the premorbid ML joint line position was significantly less in type B3 glenoids with AG components than in type A1 glenoids with SG components (-2.2 ± 2.1 mm vs. 1.1 ± 0.9 mm, P < .001). Postoperative humeral glenoid alignment was not different in any group comparisons.
In cases with posterior glenoid bone loss and retroversion (type B2 or B3 glenoids), an AG component can better correct retroversion and the glenoid ML joint line position compared with an SG component, with correction to premorbid version comparable to a type A1 glenoid with an SG component. However, restoration of the premorbid ML joint line position may not always be possible with SG or AG components in cases with more advanced central glenoid bone loss (type A2 or B3 glenoids). Further follow-up is needed to determine the clinical consequences of these findings.
本研究旨在通过三维 CT 分析，在临床队列中，根据术前病理学（改良 Walch 分类）和肩胛盂植入物类型，量化解剖全肩关节置换术中肩胛盂畸形和肱骨头对线的矫正情况。
110 例接受标准肩胛盂（SG）（n=110）或后台阶增强肩胛盂（AG）（n=62）组件的解剖全肩关节置换术的患者，在术前和术后 3 个月内均进行 CT 扫描。在术前和术后 CT 扫描上评估肩胛盂的版本、倾斜度和内外侧（ML）关节线位置，以及肱骨头对线，根据改良 Walch 分类和肩胛盂植入物类型，分析术前到术后的变化与病理学和术前解剖的关系。
平均而言，A2 型肩胛盂的术前至术后 ML 关节线位置矫正明显小于 A1 型肩胛盂（-2.3±2.1mm 比 1.1±0.9mm，P<.001）。B2 型肩胛盂（AG 组件）与 A1 型肩胛盂（SG 组件）的术前肩胛盂版本矫正没有差异（-1.7°±6.6°比-1.0°±4.0°，P=.57），两组平均恢复了术前 ML 关节线位置（0.3±1.6mm 比 1.1±0.9mm，P=.006）。B3 型肩胛盂（AG 组件）与 A1 型肩胛盂（SG 组件）的术前肩胛盂版本矫正没有差异（-0.6°±5.1°比-1.0°±4.0°，P=.72），但 B3 型肩胛盂（AG 组件）的术前至术后 ML 关节线位置矫正明显小于 A1 型肩胛盂（SG 组件）（-2.2±2.1mm 比 1.1±0.9mm，P<.001）。各组间术后肱骨头与肩胛盂的对线没有差异。
在存在后肩胛盂骨丢失和后旋（B2 或 B3 型肩胛盂）的情况下，AG 组件可比 SG 组件更好地矫正后旋和肩胛盂 ML 关节线位置，与 SG 组件的 A1 型肩胛盂相比，其肩胛盂的版本矫正相当。然而，在存在更严重的中央肩胛盂骨丢失（A2 或 B3 型肩胛盂）的情况下，SG 或 AG 组件可能无法始终恢复术前的 ML 关节线位置。需要进一步随访以确定这些发现的临床后果。
