Department of Orthopaedic Surgery, University Hospitals Cleveland Medical Center, Cleveland, OH, USA.
Department of Orthopaedic Surgery, University of Utah, Salt Lake City, UT, USA.
J Shoulder Elbow Surg. 2022 Nov;31(11):2225-2232. doi: 10.1016/j.jse.2022.04.013. Epub 2022 May 13.
During anatomic total shoulder arthroplasty (aTSA), the humeral head can be resected with or without the use of an intramedullary cutting guide, the former referred to as intramedullary (IM) resection and the latter referred to as freehand (FH) resection. Outcomes following aTSA are predicated upon the restoration of the native humeral anatomy, which can be more challenging with stemless implants. To date, no studies have determined which method of humeral head resection is superior in restoring native anatomy. Our purpose was to determine whether FH or IM resection was superior in restoring native anatomy during aTSA with stemless implants.
A review of all patients who underwent aTSA using the stemless Tornier Simpliciti Shoulder System at two academic institutions by two separate surgeons between January 2017 and June 2020 was performed. One surgeon at one institution performed stemless aTSA using the IM resection technique, while the second surgeon utilized the FH resection technique. Patients were excluded if they underwent surgery for an indication other than glenohumeral osteoarthritis, if they received a short-stem or standard-stem implant, or if they lacked adequate preoperative and postoperative Grashey radiographs. One hundred eleven patients across both institutions (51 IM, 60 FH) were included for the final radiographic assessment. The humeral head height (HH) and neck-shaft angle (NSA) were measured on preoperative and postoperative Grashey radiographs. The centers of rotation (CORs) were measured on postoperative Grashey radiographs. Patients were classified as having acceptable restoration of their native anatomy if the change (Δ) in COR or HH was ≤3 mm and ≤ 5 mm, respectively, or if the postoperative NSA was ≥130°.
IM resection had the greatest acceptable restoration of COR (90.2% IM versus 70% FH, P = .009), HH (96.1% IM vs. 63.3% FH, P < .001), and NSA (96.1% IM vs. 78.3% FH, P = .006) relative to FH resection. The mean postoperative NSAs for the IM and FH cohorts were 134.4° (±2.1°) and 133.8° (±5.4°), respectively (P = .208). The mean ΔCORs for the IM and FH groups were 1.2 (±1.5) and 2.3 (±1.2) mm, respectively (P < .001). Finally, the mean ΔHHs for the IM and FH cohorts were 1.7 (±1.4) and 4.4 (±2.9) mm, respectively (P < .001).
Restoration of the native humeral anatomy following stemless aTSA occurred at a significantly higher rate when using IM vs. FH resection.
在肩关节全关节置换术中（aTSA），可以使用或不使用髓内切割导向器切除肱骨头，前者称为髓内（IM）切除，后者称为徒手（FH）切除。aTSA 的结果取决于对原生肱骨头解剖结构的恢复，使用无柄植入物时，这可能更具挑战性。迄今为止，尚无研究确定哪种肱骨头切除方法在使用无柄植入物进行全肩关节置换时更能恢复原生解剖结构。我们的目的是确定在使用无柄 Tornier Simpliciti 肩关节系统进行全肩关节置换时，FH 或 IM 切除在恢复原生解剖结构方面是否更具优势。
对两家学术机构的两位外科医生在 2017 年 1 月至 2020 年 6 月期间使用无柄 Tornier Simpliciti 肩部系统进行全肩关节置换的所有患者进行了回顾性研究。一家机构的一位外科医生使用 IM 切除技术进行无柄全肩关节置换，而第二位外科医生则采用 FH 切除技术。如果患者因除肩袖关节炎以外的其他原因接受手术、使用短柄或标准柄植入物或缺乏术前和术后 Grashey 射线照片，则将其排除在外。来自两家机构的 111 名患者（51 名 IM，60 名 FH）被纳入最终的影像学评估。在术前和术后 Grashey 射线照片上测量肱骨头高度（HH）和颈干角（NSA）。在术后 Grashey 射线照片上测量旋转中心（COR）。如果 COR 或 HH 的变化（Δ）分别≤3mm 和≤5mm，或者术后 NSA≥130°，则认为患者的原生解剖结构恢复可接受。
与 FH 切除相比，IM 切除具有更大的 COR（90.2% IM 与 70% FH，P=.009）、HH（96.1% IM 与 63.3% FH，P<.001）和 NSA（96.1% IM 与 78.3% FH，P=.006）恢复的可接受率。IM 和 FH 队列的平均术后 NSA 分别为 134.4°（±2.1°）和 133.8°（±5.4°）（P=.208）。IM 和 FH 组的平均ΔCOR 分别为 1.2（±1.5）和 2.3（±1.2）mm（P<.001）。最后，IM 和 FH 队列的平均ΔHH 分别为 1.7（±1.4）和 4.4（±2.9）mm（P<.001）。
与 FH 切除相比，使用 IM 切除进行无柄全肩关节置换时，原生肱骨头解剖结构的恢复率显著更高。
