Fig. 1

The measured parameters of the humerus and the measuring method. A The red plane indicated cHHP. The cHHP was defined by two intersecting lines, the proximal humeral shaft axis and the line which pass through the center of the biggest osculating circle of humeral head in transverse plane which is perpendicular to proximal humeral shaft axis and perpendicular to the longest wiring of the anterior and posterior margins of the humeral head in transverse plane. The blue plane indicated tHHP. The tHHP was perpendicular to the cHHP and that contained the humeral head axis which pass through the center of the osculating circle of humeral head in cHHP and perpendicular to the wiring of the superior and inferior margins of the humeral head in cHHP; B the radius of the red circle indicated RCHH in cHHP, the red angle indicated AAHH in cHHP, the blue line indicated DHH in cHHP, the cyan line indicated THH in cHHP, the radius of the black circle indicated RCNS, and the black angle indicated AANS; C the radius of the red circle indicated RCHH in tHHP, the red angle indicated AAHH in tHHP, the blue line indicated DHH in tHHP, and the cyan line indicated THH in tHHP; D the blue angle indicated IA which is defined as the included angle of the humeral head axis and the humeral shaft axis, the red angle referred to the inferior CAHAN, the cyan angle referred to the superior CAHAN, the upper orange angle referred to UAGT, the lower orange angle referred to LAGT; E the red angle referred to the anterior CAHAN, and the blue angle referred to the posterior CAHAN; F the red dotted line referred to PO, and the blue dotted line referred MO; G the cyan region referred to VIG, and the red line referred to LIG; H the blue line referred to HGT, the cyan line referred to HLT, the red line referred to HIG, and the orange angle referred to CAIG