Suter Thomas, Kolz Christopher W, Tashjian Robert Z, Henninger Heath B, Gerber Popp Ariane
Department of Orthopaedics, Orthopaedic Research Laboratory, University of Utah, Salt Lake City, UT, USA; Department of Orthopaedic Surgery, Kantonsspital Baselland, Liestal, Switzerland.
Department of Orthopaedics, Orthopaedic Research Laboratory, University of Utah, Salt Lake City, UT, USA.
J Shoulder Elbow Surg. 2017 Feb;26(2):343-351. doi: 10.1016/j.jse.2016.07.010. Epub 2016 Oct 6.
The best chance that a shoulder arthroplasty will restore motion and muscle balance across the glenohumeral joint is by closely replicating natural articular morphology. Defining the humeral osteotomy plane along clear landmarks at the anatomic neck is critical. We hypothesized that a new osteotomy, based on alternative landmarks on the anatomic neck, would restore 3-dimensional humeral head morphology more reliably than the traditional osteotomy.
The anatomic neck was digitized in 30 human cadaver shoulders and compared with its 3-dimensional computed tomography reconstruction. Two different osteotomy techniques were virtually performed: the traditional, following the anterosuperior anatomic neck; and a new technique, defined by the inferoanterior anatomic neck. The length-width difference and orientation (retroversion, inclination) of the resection area were compared between the techniques and with native anatomy.
Length-width difference of the anterosuperior resection area was higher than in the inferoanterior osteotomy (6 ± 2 mm vs. 3 ± 1 mm; P < .001). Retroversion of the anterosuperior resection plane was higher than the native head (50° ± 12° vs. 37° ± 11°; P < .001), whereas retroversion after the inferoanterior osteotomy (32° ± 12°) did not differ from native (P = .057). Inclination differed after the anterosuperior osteotomy (129° ± 5°) and the inferoanterior osteotomy (127° ± 4°) compared with the native head (134° ± 4°; P ≤ .001).
The inferoanterior referenced osteotomy generated a more circular resection area, matching the native humeral head retroversion more closely than in the anterosuperior technique. This study suggests that in shoulder arthroplasty, the humeral resection level should be referenced at the inferoanterior rather than the anterosuperior anatomic neck. Further studies should investigate the biomechanical effects of this alternative resection plane.
肩关节置换术恢复盂肱关节活动度和肌肉平衡的最佳机会是紧密复制自然关节形态。沿着解剖颈的清晰标志确定肱骨截骨平面至关重要。我们假设，基于解剖颈上不同标志的一种新截骨术，比传统截骨术能更可靠地恢复三维肱骨头形态。
对30例人体尸体肩关节的解剖颈进行数字化处理，并与其三维计算机断层扫描重建图像进行比较。虚拟实施两种不同的截骨技术：传统技术，沿解剖颈前上方进行；新技术，由解剖颈下前方确定。比较两种技术之间以及与正常解剖结构相比，切除区域的长宽差和方向（后倾、倾斜）。
前上方切除区域的长宽差高于下前方截骨术（6±2mm对3±1mm；P<.001）。前上方切除平面的后倾大于正常肱骨头（50°±12°对37°±11°；P<.001），而下前方截骨术后的后倾（32°±12°）与正常后倾无差异（P=.057）。与正常肱骨头（134°±4°）相比，前上方截骨术（129°±5°）和下前方截骨术（127°±4°）后的倾斜度均有差异（P≤.001）。
下前方参照截骨术产生的切除区域更接近圆形，与正常肱骨头后倾的匹配程度比前上方技术更高。本研究表明，在肩关节置换术中，肱骨切除水平应以解剖颈下前方而非前上方为参照。进一步研究应探讨这种替代切除平面的生物力学效应。
