Sahu Dipit, Joshi Moksha, Rathod Vaibhavi, Nathani Priyansh, Valavi Anisha S, Jagiasi Jairam D
Sir H.N. Reliance Foundation Hospital, Mumbai, Maharashtra, India.
Mumbai Shoulder Institute, Mumbai, Maharashtra, India.
JSES Int. 2020 Jul 22;4(4):992-1001. doi: 10.1016/j.jseint.2020.06.008. eCollection 2020 Dec.
Total anatomic and reverse shoulder prostheses are designed to match the dimensions of the native bony anatomy. Chinese and Japanese bony dimensions of the shoulder have been found to be different from that of the Caucasian population. We hypothesized that the geometric dimensions of the humeral head and glenoid in the Indian population would also be different from that of the Caucasian population.
Fifty patients underwent computerized tomographic scans of their normal shoulders. We calculated the superoinferior (SI) diameter of the humeral head, anteroposterior diameter of the humeral head, radius of curvature of the humeral head, humeral head retroversion, humeral head thickness, inclination angle, critical shoulder angle, greater tuberosity angle, glenoid width, glenoid length, radius of curvature of the glenoid, glenoid inclination angle, and glenoid version.
The radius of curvature of the humeral head averaged 22.9 ± 1.7 mm, the articular surface thickness 17.1 ± 1.6 mm, and the SI diameter 42.3 ± 3 mm. The SI diameter strongly correlated with the thickness ( = 0.617, = .001). The anteroposterior/SI articular surface diameter ratio averaged 0.9 ± 0.9, the articular surface thickness/radius of curvature ratio 0.7 ± 0.9, the inclination angle 133.8 ± 6.4, and the retroversion angle 33.5° ± 8.5°. The radius of curvature of the glenoid averaged 23.3 ± 3.4 mm, the glenoid width 24.0 ± 2 mm, the SI length 31.3 ± 2.2 mm, the glenoid inclination angle 78.7° ± 4.8°, and the glenoid retroversion 1.8° ± 3.8°.
Compared with the Western population, our cohort had a smaller humeral radius of curvature ( = .04), smaller articular surface diameter ( = .001), smaller inclination angle ( = .003), larger retroversion angle of the humeral head ( < .001), and smaller glenoid length and width ( < .0001). Most of the implant companies did not have smaller sized combinations of humeral heads with thickness to match our population. The glenoid width of females in our cohort was found to be smaller for the smallest size of the glenoid base plate.
Smaller sized options in humeral head diameter and thickness of the anatomic prosthesis and glenoid baseplate of the reverse shoulder prosthesis need to be made available to suit our population and avoid a mismatch.
全解剖型和反置式肩关节假体旨在匹配天然骨骼解剖结构的尺寸。已发现中国人和日本人的肩部骨骼尺寸与白种人不同。我们推测印度人群肱骨头和肩胛盂的几何尺寸也会与白种人不同。
50例患者接受了正常肩部的计算机断层扫描。我们计算了肱骨头的上下径（SI）、肱骨头的前后径、肱骨头的曲率半径、肱骨头后倾角、肱骨头厚度、倾斜角、临界肩角、大结节角、肩胛盂宽度、肩胛盂长度、肩胛盂的曲率半径、肩胛盂倾斜角和肩胛盂旋转角度。
肱骨头的曲率半径平均为22.9±1.7mm，关节面厚度为17.1±1.6mm，上下径为42.3±3mm。上下径与厚度密切相关（r = 0.617，P = 0.001）。关节面前后径与上下径之比平均为0.9±0.9，关节面厚度与曲率半径之比为0.7±0.9，倾斜角为133.8±6.4，后倾角为33.5°±8.5°。肩胛盂的曲率半径平均为23.3±3.4mm，肩胛盂宽度为24.0±2mm，上下长度为31.3±2.2mm，肩胛盂倾斜角为78.7°±4.8°，肩胛盂后倾为1.8°±3.8°。
与西方人群相比，我们的队列中肱骨头的曲率半径较小（P = 0.04），关节面直径较小（P = 0.001），倾斜角较小（P = 0.003），肱骨头后倾角较大（P < 0.001），肩胛盂长度和宽度较小（P < 0.0001）。大多数植入物公司没有厚度与之匹配的较小尺寸的肱骨头组合。我们队列中女性的肩胛盂宽度对于最小尺寸的肩胛盂基板来说较小。
需要提供尺寸更小的解剖型假体的肱骨头直径和厚度以及反置式肩关节假体的肩胛盂基板，以适合我们的人群并避免不匹配。
