Measurement And Analysis Of The Glenoid Bony Anatomy

BackgroundShoulder osteoarthritis can be caused by a variety of etiological factors, which should be proceeded with total shoulder arthroplasty to improve the articular function and relieve pain. Since the 70's in last century, many proximal humeral prosthesis have been invented, but the glenoid prosthesis developed slowly. So the design of the glenoid prosthesis is a great challenge for us. The ultimate goal of total shoulder replacement is to reconstruct the normal glenohumeral anatomy as much as possible in order to recover its function. Therefore, the accurate mesurement of glenoid bony structure is very important for both glenoid prosthetic design and the process of total shouler replacement.ObjectiveTo investigate and analyze the anatomic structure of glenoid with multi-slice CT and its post-processing techniques. To provide anatomical data to the new glenoid prosthesis, and to provide the necessary pre-operative evaluation for total shoulder arthroplasty.MethodsTen cadaveric(left 5, right 5) and ten(left 5, right 5) fresh cadaveric(left 5, right 5) scapulas were used to establish and verify the methods of mesurement. The sex and the age of the cadavers are unknown. All the scapulas were scanned with Siemens Somatom Sensation 16-slice scanner. The images were delivered to LEONARDO workstation and were analyzed with post-processing technique of volume rendering technique (VRT) and multiplanar reformation (MPR). The parameters of scapulas were measured by the MSCT and direct anatomic measurement. Difference between the two methods were analyze by statistic.100 volunteers with two healthy shoulders (61 male,39 female), average 38.9 years old (19-60) were collected in ChongQing, China. The same methods were used to mesure the glenoid parameters of the volunteers.The parameters of glenoid include maximum antero-posterior width (MAPW), antero-posterior radius of curvature (APROC), maximum supero-inferior height (MSIH), supero-inferior radius of curvature (SIROC), superior fixation angle (SFA), inferior fixation angle (IFA), anterior fixation angle (AFA), posterior fixation angle (PFA), superior fixation depth (SFD), inferior fixation depth (IFD), anterior fixation depth (AFD), posterior fixation depth (PFD), superior version angle (SVA), middle version angle (MVA), and inferior version angle (IVA). The average values were analysed by spss13.0 to explore the difference between female and male, left and right scapulas. There have statistical difference between two groups if P<0.05.Results1 The results of the twenty glenoid cadaveric by MSCT is MAPW2.78cm±0.24cm (2.38cm-3.12cm) APROC5.32cm±0.84cm (4.20cm-6.83cm) MSIH3.82cm±0.18cm (3.42cm-4.01cm) SIROC4.28cm±0.74cm (3.12cm-5.69cm) SFA142.30°±6.58°(132.00°-150.00°) IFA124.30°±3.95°(119.00°-132.00°) AFA63.20°±4.42°(56.00°-68.00°) PFA45.20°±5.65°(39.00°-58.00°) SFD2.81cm±0.43cm (2.13cm-3.38cm) IFD4.99cm±1.34cm (2.61cm-6.32cm) AFD3.95cm±0.52cm (3.35cm-4.96cm) PFD1.96cm±0.24cm (1.70cm-2.36cm) SVA1.60°±3.60°(-3.00°-7.00°) MVA0.10°±2.33°(-4.00°-4.00°) IVA-1.20°±2.35°(-5.00°-2.00°) The results of the twenty glenoid cadaveric by direct anatomic measurement is: MAPW 2.81cm±0.25cm (2.37cm-3.10cm) APROC 5.29cm±0.81cm (4.06cm-6.74cm) MSIH 3.82cm±0.23cm (3.39cm-4.12cm) SIROC 4.32cm±0.59cm (3.47cm-5.43cm) SFA 142.70°±7.56°(128.00°-152.00°) IFA 123.90°±5.57°(114.00°-133.00°) AFA 62.80°±4.10°(56.00°-68.00°) PFA 45.00°±6.43°(36.00°-58.00°) SFD 2.85cm±0.44cm (2.04cm-3.45cm) IFD 4.93cm±1.54cm (2.15cm-6.46cm) AFD 3.94cm±0.47cm (3.37cm-4.73cm) PFD 1.97cm±0.29cm (1.64cm-2.59cm) SVA 1.90°±3.90°(-2.00°-8.00°) MVA 0°±2.75°(-5.00°-4.00°) IVA -1.30°±3.16°(-7.00°-3.00°)2 The results of the two hundryed shoulders of the volunteers is MAPW 2.51cm±0.30cm (1.71cm-3.15cm) APROC 5.59cm±1.13cm (3.06cm-8.92cm) MSIH 3.46cm±0.31cm (2.69cm-4.15cm) SIROC 3.99cm±0.54cm (2.58cm-5.82cm) SFA 139.2°±11.0°(110°-168°) IFA 122.7°±7.5°(95°-156°) AFA 63.9°±5.4°(46°-79°) PFA 55.9°±16.7°(32°-89°) SFD 2.59cm±0.53cm (1.29cm-3.50cm) IFD 4.71cm±1.62cm (1.80cm-9.20cm) AFD 3.46cm±0.56cm (1.73cm-5.28cm) PFD 2.10cm±0.55cm (1.15cm-3.71cm) SVA 1.5°±4.8°(-10°-14°) MVA -0.3°±3.9°(-11°-8°) IVA -1.9°±4.5°(-15°-9°)3 There were no significant difference in all parameters of cadavers between the CT measured group and the anatomic measured group.4 There were significant differences in MAPW, MSIH, SIROC, AFD, PFD, MVA and IVA between female and male (P<0.05)5 There were no significant differences in all parameters except AFA between left and right shoulders.6 There have been corelations between the following parameters:MAPW and MSIH, APROC and SIROC, MSIH and SIROC, AFA and AFD, PFA and PFD, SVA and MVA, SVA and IVA, MVA and IVA.Conclusions1 The multi-slice CT and its post-processing techniques are simple and accurate methods for measurement of glenoid bony anatomic parameters.2 We got a series of glenoid bony anatomic parameters by this experiment. That could be useful in designing of the glenoid prosthesis.3 There were significant differences between male and female in some parameters especially the ones of shape and the version angle of glenoid. The most glenoid parameters were no significant differences between left and right. Therefore, when total shoulder arthroplasty should be performed on one affected shoulder, the anatomic data of the opposite side can be available for the shoulder arthroplasty.