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Aim: To demonstrate how reverse shoulder arthroplasty (RSA) planning software could be used to improve how the trainees position glenoid and humeral implants and obtain optimal simulated range of motion (ROM). Methods: We selected four groups of five various level participants: medical student (MS), junior resident (JR), senior resident (SR), and shoulder expert (SE). Thereafter, the 20 participants planned five cases of arthritic shoulders for a RSA on a validated planning software following three phases: (1) no guidelines and no ROM feedback, (2) guidelines but no ROM feedback, and (3) guidelines and ROM feedback. We evaluated the final simulated impingement-free ROM, the choice of the implant (baseplate size, graft, glenosphere), and the glenoid implant positioning. Results: MS planning were significantly improved by the ROM feedback only. JR took the best advantage of both guidelines and ROM in final results. SR planning were less performant than SE into phase 1 regarding flexion, external rotation, and adduction (respectively − 10°, p = 0.03; − 11°, p = 0.003; and − 3°, p = 0,03), but reached similar results into phase 3 (respectively − 2°, p = 0.329; − 4°, p = 0.44; − 2°, p = 0.319). For MS, JR, and SR, we observed a systematic improvement in the agreement over the study course. The glenoid diameter remained highly variable even for SE. Comparing glenoid implant position to SE, the distance error decreased with advancing phases. Conclusion: Planning software can be used as a simulation training tool to improve implant positioning in shoulder arthroplasty procedures. [ABSTRACT FROM AUTHOR]

Purpose: Incorrect positioning of components during total knee arthroplasty (TKA) increases the risk of pain, instability, and early revision. The purpose of this study was to compare 3D planning-assisted and a conventional system for TKA positioning. We hypothesized that the use of three-dimensional CT-scan planning and custom cutting guides would increase the accuracy of component positioning.Methods: A randomized, controlled, prospective study of two groups was performed. In one group, patient-specific custom cutting guides (PSCG) were used for component positioning based on 3D CT-scan planning. In the control group, TKA was performed with a conventional ancillary system. The components' positioning angles were measured on 3D reconstructions. The main evaluation criterion was the percentage of outliers outside of a target zone of ± 3° for the coronal positioning of the femoral component.Results: Eighty patients were included. The percentage of outliers for the femoral component was significantly lower in the 3D-guided group (1 patient) compared to the control group (7 patients p = 0.02). The coronal femoral angle was restored with greater accuracy in the 3D-assisted group (- 0.1° ± 1.4°) compared to the control group (1.6° ± 2.5°). Surgery was significantly shorter in the 3D group. The clinical outcomes were better in the 3D group at the two year follow-up with fewer failures and a lower standard deviation in IKS scores.Conclusion: The use of a 3D planning and custom guides can improve TKA component positioning by increasing the accuracy of implants alignment and reducing the percentage of outliers. The same benefit was not demonstrated for the global knee alignment and the clinical scores with no indisputable clinical advantage for the PSCG. [ABSTRACT FROM AUTHOR]

Purpose: Glenoid loosening after total shoulder arthroplasty (TSA) is influenced by the position of the glenoid component. 3D planning software and patient-specific guides seem to improve positioning accuracy, but their respective individual application and role are yet to be defined. The aim of this study was to evaluate the accuracy of freehand implantation after 3D pre-operative planning and to compare its accuracy to that of a targeting guide.Method: Seventeen patients scheduled for TSA for primary glenohumeral arthritis were enrolled in this prospective study. Every patient had pre-operative planning, based on a CT scan. Glenoid component implantation was performed freehand, guided by 3D views displayed in the operating room. The position of the glenoid component was determined by manual segmentation of post-operative CT scans and compared to the planned position. The results were compared to those obtained in a previous work with the use of a patient-specific guide.Results: The mean error for the central point was 2.89 mm (SD ± 1.36) with the freehand method versus 2.1 mm (SD ± 0.86) with use of a targeting guide (p = 0.05). The observed difference was more significant (p = 0.03) for more severely retroverted glenoids (> 10°). The mean errors for version and inclination were respectively 4.82° (SD ± 3.12) and 4.2° (SD ± 2.14) with freehand method, compared to 4.87° (SD ± 3.61) and 4.39° (SD ± 3.36) with a targeting guide (p = 0.97 and 0.85, respectively).Conclusion: 3D pre-operative planning allowed accurate glenoid component positioning with a freehand method. Compared to the freehand method, patient-specific guides slightly improved the position of the central point, especially for severely retroverted glenoids, but not the orientation of the component. [ABSTRACT FROM AUTHOR]