Voss Andreas, Dyrna Felix, Achtnich Andrea, Hoberman Alex, Obopilwe Elifho, Imhoff Andreas B, Mazzocca Augustus D, Beitzel Knut
Department of Orthopaedic Surgery, University of Connecticut, Farmington, CT, 06034, USA.
Department of Orthopaedic Sports Medicine, Technical University of Munich, Munich, Germany.
Knee Surg Sports Traumatol Arthrosc. 2017 Jul;25(7):2004-2012. doi: 10.1007/s00167-017-4539-1. Epub 2017 Apr 22.
Recent techniques for acromioclavicular (AC) joint reconstruction focus on additional AC cerclage to coracoclavicular (CC)-reconstructions. Due to the specific slim bone morphology at the acromion, there are concerns regarding these additional bone tunnels, as they may predispose to fracture and break out. The purpose of this study was to investigate anatomic properties of the acromion which may help improve surgical techniques directed at injuries to the AC joint. It was hypothesized that via measurements of thickness and density points of increased strength and support could be identified on the acromion.
Eighty-five fresh frozen cadaveric shoulders were used for this study. A standardized 3D-net was developed and thicknesses of the acromion were taken from defined points using a certified caliper. To define the acromial arch, the angle and radius of curvature between the antero-lateral, the highest point of the acromial arch and the postero-lateral aspect of the acromion were measured. Additional bone mineral density (BMD) evaluation was performed on 43 specimens in an anterio-posterior and latero-medial direction using 5-mm slices with a maximum of 10 and 6 slices, respectively.
Median specimen age was 63.0 (range 36) years (55 female, and 30 male). There was no statistical significance between male (62.0, range: 35 years) and female (64.5, range 32 years) regarding age (n.s.). Thickness of acromion points of interest were ranging from 3.5 to 24.3 mm. Median radius of curvature of acromial arch for female was 48.2 (range 92.7) mm and 66.2 (range 85.6) for male (p = 0.019). The median angle for female specimens was 21.4° (range: 44.6°) and 23.3° (range 51.7°) for male (p = 0.047). The latero-medial measurements showed significant difference between the region of interest (ROI): 1 and 4, 5, 6 (p = 0.001, p = 0.001, p = 0.001), 2 and 4, 5, 6 (p = 0.007, p = 0.001, p = 0.001), 3 and 5, 6 (p = 0.001, p = 0.001), 4 and 5, 6 (p = 0.010, p = 0.001). Antero-posterior measurements showed significant difference between the ROI: 1 and 8 (p = 0.031).
The posterior-medial acromion close to the AC joint revealed the highest BMD with an increasing density from lateral to medial. In combination with thickness measurements this region would support additional anatomical fixation of the AC joint using bone tunnels if necessary.
To anatomically reproduce the insertions of the AC ligaments at the acromion, either bone tunnels or anchors are needed. Therefore, several techniques have been developed. This study provides the anatomical data for these techniques and confirms the reconstructive approach of techniques using anatomical points of fixation and orientation.
近期肩锁关节（AC）重建技术着重于在喙锁（CC）重建基础上增加AC环扎。由于肩峰处骨骼形态特殊且纤细，人们担心这些额外的骨隧道可能导致骨折和骨隧道破裂。本研究旨在探究肩峰的解剖学特性，以助于改进针对AC关节损伤的手术技术。研究假设通过测量肩峰厚度和密度，可识别出强度和支撑性增加的点。
本研究使用了85个新鲜冷冻尸体肩部标本。开发了标准化的三维网络，并使用经认证的卡尺从特定点测量肩峰厚度。为确定肩峰弓，测量了肩峰前外侧、肩峰弓最高点与肩峰后外侧之间的角度和曲率半径。对43个标本分别在前后方向和内外方向进行额外的骨密度（BMD）评估，切片厚度为5毫米，前后方向最多10片，内外方向最多6片。
标本的中位年龄为63.0岁（范围36岁）（55名女性，30名男性）。男性（62.0岁，范围35岁）和女性（64.5岁，范围32岁）在年龄方面无统计学差异（无显著性）。感兴趣的肩峰点厚度范围为3.5至24.3毫米。女性肩峰弓的中位曲率半径为48.2毫米（范围92.7毫米），男性为66.2毫米（范围85.6毫米）（p = 0.019）。女性标本的中位角度为21.4°（范围44.6°），男性为23.3°（范围51.7°）（p = 0.047）。内外方向测量显示感兴趣区域（ROI）之间存在显著差异：1与4、5、6（p = 0.001，p = 0.001，p = 0.001），2与4、5、6（p = 0.007，p = 0.001，p = 0.001），3与5、6（p = 0.001，p = 0.001），4与5、6（p = 0.010，p = 0.001）。前后方向测量显示ROI之间存在显著差异：1与8（p = 0.031）。
靠近AC关节的肩峰后内侧显示出最高的骨密度，且从外侧到内侧密度增加。结合厚度测量结果，如有必要，该区域将支持使用骨隧道对AC关节进行额外的解剖固定。
为了在解剖学上重现AC韧带在肩峰的附着，需要使用骨隧道或锚钉。因此，已开发出多种技术。本研究为这些技术提供了解剖学数据，并证实了使用解剖学固定点和方向的技术的重建方法。
