Matache Bogdan A, Alnusif Naser, Chaoui Jean, Walch Gilles, Athwal George S
NYU Langone Health, New York, NY, USA.
Roth|McFarlane Hand & Upper Limb Centre, St. Joseph's Healthcare London, London, ON, Canada.
JSES Int. 2020 Oct 10;5(1):98-101. doi: 10.1016/j.jseint.2020.08.016. eCollection 2021 Jan.
The Walch type B pattern of glenohumeral osteoarthritis is characterized by posterior humeral head subluxation (PHHS). At present, it is unknown whether the percentage of subluxation measured on axillary radiographs is consistent with measurements on 2-dimensional (2D) axial or 3-dimensional (3D) volumetric computed tomography (CT). The purpose of this study was to evaluate PHHS across imaging modalities (radiographs, 2D CT, and 3D CT).
A cohort of 30 patients with Walch type B shoulders underwent radiography and standardized CT scans. The cohort comprised 10 type B1, 10 type B2, and 10 type B3 glenoids. PHHS was measured using the scapulohumeral subluxation method on axillary radiographs and 2D CT. On 3D CT, PHHS was measured volumetrically. PHHS was statistically compared between imaging modalities, with ≤ .05 considered significant.
The mean PHHS value for the entire group was 69% ± 24% on radiographs, 65% ± 23% with 2D CT, and 74% ± 24% with 3D volumetric CT. PHHS as measured on complete axillary radiographs was not significantly different than that measured on 2D CT ( = .941). Additionally, PHHS on 3D volumetric CT was 9.5% greater than that on 2D CT ( < .001). There were no significant differences in PHHS between the type B1, B2, and B3 groups with 2D or 3D CT measurement techniques ( > .102).
Significant differences in PHHS were found between measurement techniques ( < .035). A 9.5% difference in PHHS between 2D and 3D CT can be mostly accounted for by the linear (2D) vs. volumetric (3D) measurement techniques (a linear 80% PHHS value is mathematically equivalent to a volumetric PHHS value of 89.6%). Surgeons should be aware that subluxation values and therefore thresholds vary across different imaging modalities and measurement techniques.
盂肱关节骨关节炎的Walch B型模式的特征是肱骨头后脱位（PHHS）。目前，尚不清楚在腋位X线片上测量的半脱位百分比是否与二维（2D）轴向或三维（3D）容积计算机断层扫描（CT）上的测量结果一致。本研究的目的是评估不同成像方式（X线片、2D CT和3D CT）下的PHHS情况。
对30例Walch B型肩关节患者进行了X线摄影和标准化CT扫描。该队列包括10个B1型、10个B2型和10个B3型关节盂。在腋位X线片和2D CT上使用肩胛肱半脱位方法测量PHHS。在3D CT上，对PHHS进行容积测量。对不同成像方式下的PHHS进行统计学比较，P≤0.05认为具有显著性差异。
整个组在X线片上的平均PHHS值为69%±24%，2D CT为65%±23%，3D容积CT为74%±24%。在完整腋位X线片上测量的PHHS与2D CT测量的结果无显著差异（P = 0.941）。此外，3D容积CT上的PHHS比2D CT上的大9.5%（P < 0.001）。使用2D或3D CT测量技术时，B1、B2和B3组之间的PHHS无显著差异（P > 0.102）。
测量技术之间发现了PHHS的显著差异（P < 0.035）。2D和3D CT之间PHHS的9.5%差异主要可由线性（2D）与容积（3D）测量技术解释（线性80%的PHHS值在数学上等同于容积PHHS值89.6%）。外科医生应意识到半脱位值以及因此的阈值在不同成像方式和测量技术中有所不同。
