Purpose: To evaluate the normal glenoid size of the Koreans in their 7th and 8th decades with the Computed tomographic (CT) studies.

Materials and Methods: The CT images were obtained from normal scapulae of the patients (mean age : 68.8, range 62–76) with the humeral fracture cases. A Display workstation version 2.0.73.315 was used to measure the scans to determine the maximal superoinferior(SI) and anteroposterior(AP) diameter of the osseous glenoid vault.

Results: The average diameter of curvature of the glenoid were 31.2±2.3mm(range, 27 to 34mm) in the superior-inferior directions and 26.1±2.4mm(range, 22 to 31mm) in anterior-posterior.

Conclusion: This study showed the normal glenoid size of the Korean and it is smaller than the size which the international literature reported. It would be important factor for the treatment of fracture or arthroplasty implant designs.

In cases of severe postdysplastic coxarthosis, it seems to be impossible to recognize acetabular geometry and the real femoral position on a plain X-ray because the real diameters and angles can be disfigured when projected. Computed tomography (CT) provides important information to the surgeon about the concavity, shape and stereotomy of the acetabulum. It is quite difficult to correctly evaluate severely changed hips. CT displays more precise acetabular diameters and angles than a plain radiograph. Because of the high density of bony tissue, the CT makes it easy to produce a three-dimensional display of the hip. From September 1995 to December 1998, 224 patients (148 female, 76 male) underwent arthroplasty using a non-cemented prosthesis according to Zweymüller. A total of 236 hip joints were operated and classified as Crowe Group I (76 hips), Crowe Group II (149 hips), and Crowe Group III (11 hips). There were no Crowe Group IV hips. A total of 96 patients were examined by 3D CT in preoperative planning. Based on CT results, four joints were not recommended for an operative solution. CT protocol: scanner Elscint TWIN II, slice 2.5 mm, 120 kV, 285 mAs, matrix 3402,. No. of slices: 40–50, incremental dual acquisition. Postprocessing: axial images, multiplanar reconstructions, 3D SSD. Acetabular stereometry: superoinferior diameter, anteroposterior diam., depth, bottom thickness, femoral neck anteversion angle and subtrochanteric marrow diameter. A three-dimensional CT of the hip is a very effective tool for preoperative assessment

Shoulder arthroplasty is used to treat osteoarthritis, post-traumatic arthritis, and avascular necrosis. Modular components allow for natural variability in shoulder anatomy, including retroversion and head-neck angles. Surgical options include anatomic or guide-assisted cut at a fixed retroversion and head-neck angle. The purpose of this study was to determine the variability between head height (HH) and anteroposterior (AP) and superoinferior (SI) diameters using anatomic and guide-assisted humeral head cuts. Computed tomography scans of 10 cadaveric shoulder specimens (5 male, 5 female) were converted to 3D models. An anatomic humeral head cut plane was placed at the anatomic head–neck junction maintaining the posterior cuff insertion for all shoulders by a fellowship trained shoulder surgeon. Cut planes were generated for standard implant head neck angles (125°,130°,135°, and 140°) and retroversion angles (20°,30°, and 40°) in commercial cutting guides, for a combination of 12 repeated cut conditions per specimen. The humeral HH and the head diameter were measured in the AP and the SI planes for anatomic and guide-assisted osteotomy planes. Differences were compared using a separate two-way repeated measures ANOVA for each dependent variable. Guide-assisted cuts showed no significant effect on HH due to head-neck (p=0.205) or retroversion angles (p=0.190). These results persisted by gender (male: head-neck p=0.659 and retroversion p=0.386; female: head-neck p=0.204 and retroversion p=0.190). SI diameter increased by 1.3 mm with increasing head-neck angle (p<0.001), but there was no effect due to retroversion (p=0.148). A head-neck angle of 125° caused the greatest decrease in SI diameter of −2.8 mm compared to the anatomic cut, averaged over the retroversion range. The greatest reduction of SI diameter, −3.4 mm compared to anatomic, occurred with 125° head-neck angle and 20° retroversion. By gender, males showed a significant effect from head-neck angle (p=0.008), but females did not (p=0.077). There was no significant difference from retroversion in either gender group (male p=0.792; female p=0.057). There was no significant difference in AP diameter by head-neck (p=0.192) or retroversion angles (p=0.168). These results persisted in the males (head-neck p=0.420 and retroversion p=0.780). In females, there was no effect from head-neck angle (p=0.232); however, retroversion angle trended toward significance (p=0.050). For patients whose natural anatomy falls outside the range of the commercial cut guides, templated resection may result in deviation from natural humeral head dimensions. Due to the large variability in anatomic retroversion and head-neck angles in the subjects of this study, further study with a larger sample size is needed to investigate observed trends. These preliminary results have implications for manufacturers to create guides to represent a larger segment of the population, and surgeons' intra-operative choice

Aims

In computer simulations, the shape of the range of motion (ROM) of a stem with a cylindrical neck design will be a perfect cone. However, many modern stems have rectangular/oval-shaped necks. We hypothesized that the rectangular/oval stem neck will affect the shape of the ROM and the prosthetic impingement.