Background. Radiological and clinical results of total shoulder arthroplasty are dependent upon ability to accurately measure and correct glenoid version. There are a variety of imaging modalities and computer-assisted reconstruction programmes that are employed with varying degrees of success. We have compared three freely available modalities: unformatted 2D CT; formatted 2D CT; and 3D CT reconstructions. Methods. A retrospective analysis of 20 shoulder CT scans was performed. Glenoid version was measured at the estimated mid-point of the glenoid from unformatted 2D CT scans (Scapula body method) and again following formatting of 2D CT scans in the plane of the scapula (Friedman method). 3D scapula reconstructions were also performed by downloading CT DICOM images to OSIRIX 6 and plotting ROI points on Friedman's axis to most accurately define glenoid version. Both measurements taken from 2D CT were compared to those from 3D CT. Eleven CT scans were of male patients, 9 female. Mean age was 55.2 years (Range: 23–77 years). Fourteen scans were performed for trauma, 6 for arthroplasty. Twelve scans were of the left shoulder. Results. Mean glenoid version as measured on: unformatted 2D CT was −4.51 degrees (−29.67 – 7.22 degrees); formatted 2D CT was −2.04 degrees (−36.96 – 9.72 degrees); and on 3D reconstructions was −3.01 degrees (−32.57 – 14.33 degrees). Sixty percent of measurements taken on formatted 2D CT were within 3 degrees of those taken on 3D reconstructions, with 85% within 5 degrees. This proportion fell to 30% and 50% respectively on unformatted 2D CT. Discussion. In this small study measurements of glenoid version taken on formatted 2D CT demonstrated greater accuracy than unformatted 2D CT when comparing to 3D reconstruction measurements as the gold standard. Although we demonstrated no significant statistical difference between measurements in this pilot study we believe significance will be obtained as we increase our sample size

An adult acquired flatfoot deformity (AAFD) is a complex 3D deformity. Surgical correction consists of a medial calcaneal osteotomy (MCO) but shows limitations due to the current 2D assessment. Therefore, the aim is to determine the influence of an MCO on the longitudinal foot arch assessed by 2D and 3D weightbearing CT (WBCT). Seventeen patients with a mean age of 44,5 years (range 18–66 yrs) were retrospectively included. MCO was indicated in a stage II AAFD (N=15) and a post-traumatic valgus deformity (N=2). Pre- and post-operative imaging was obtained from a WBCT. The height of the longitudinal foot arch was measured as the distance from the navicular tuberositas to the floor (Navicular Height, NH) on 2D CT images (NH. 2D. ) and computed on 3D CT data (NH. 3D. ). Additionally, 3D assessment could compute the degree of exorotation (α) of the navicular bone towards the vertical axis. The mean pre-operative NH. 2D. and NH. 3D. were respectively 29.57mm ± 7.59 and 28.34mm ± 6.51. These showed to be statistically different from the mean post-operative NH. 2D. and NH. 3D. , respectively 31.62mm ± 6.69 and 31.67mm ± 6.47 (p < 0,001). A statistical difference was also found when comparing the mean degree of exorotation in pre- and post-operative, respectively: α. pre. =14.08° ± 4,92 and the α. post. =19,88° ± 3.50 (p < 0,001). This study demonstrates a significant correction of the longitudinal foot arch after a MCO. The novelty is attributed to the accurate degree of rotation assessment using WBCT. This information could be assistive to optimise a pre-operative planning

We have previously shown that joint distraction and movement with a hinged external fixation device for 12 weeks was useful for repairing a large articular cartilage defect in a rabbit model. We have now investigated the results after six months and one year. The device was applied to 16 rabbits who underwent resection of the articular cartilage and subchondral bone from the entire tibial plateau. In group A (nine rabbits) the device was applied for six months. In group B (seven rabbits) it was in place for six months, after which it was removed and the animals were allowed to move freely for an additional six months. The cartilage remained sound in all rabbits. The areas of type II collagen-positive staining and repaired soft tissue were larger in group B than in group A. These findings provide evidence of long-term persistence of repaired cartilage with this technique and that weight-bearing has a positive effect on the quality of the cartilage.