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BACKGROUND: Accurate assessment of glenoid inclination is of interest for a variety of conditions and procedures. The purpose of this study was to develop an accurate and reproducible measurement for glenoid inclination on standardized anterior-posterior (AP) radiographs and on computed tomography (CT) images. MATERIALS AND METHODS: Three consistently identifiable angles were defined: Angle by line AB connecting the superior and inferior glenoid tubercle (glenoid fossa) and the line identifying the scapular spine; angle by line AB and the floor of the supraspinatus fossa; angle by line AB and the lateral margin of the scapula. Experimental study: these 3 angles were measured in function of the scapular position to test their resistance to rotation. Conventional AP radiographs and CT scans were acquired in extension/flexion and internal/external rotation in a range up to ±40°. Clinical study: the inter-rater reliability of all angles was assessed on AP radiographs and CT scans of 60 patients (30 with proximal humeral fractures, 30 with osteoarthritis) by 2 independent observers. RESULTS: The experimental study showed that angle and have a resistance to rotation of up to ±20°. The deviation from neutral position was not more than ±10°. The results for the inter-rater reliability analyzed by Bland-Altman plots for the angle fracture group were (mean ± standard deviation) -0.1 ± 4.2 for radiographs and -0.3 ± 3.3 for CT scans; and for the osteoarthritis group were -1.2 ± 3.8 for radiographs and -3.0 ± 3.6 for CT scans. CONCLUSION: Angle is the most reproducible measurement for glenoid inclination on conventional AP radiographs, providing a resistance to positional variability of the scapula and a good inter-rater reliability.

Congenital or posttraumatic bone deformity may lead to reduced range of motion, joint instability, pain, and osteoarthritis. The conventional joint-preserving therapy for such deformities is corrective osteotomy-the anatomical reduction or realignment of bones with fixation. In this procedure, the bone is cut and its fragments are correctly realigned and stabilized with an implant to secure their position during bone healing. Corrective osteotomy is an elective procedure scheduled in advance, providing sufficient time for careful diagnosis and operation planning. Accordingly, computer-based methods have become very popular for its preoperative planning. These methods can improve precision not only by enabling the surgeon to quantify deformities and to simulate the intervention preoperatively in three dimensions, but also by generating a surgical plan of the required correction. However, generation of complex surgical plans is still a major challenge, requiring sophisticated techniques and profound clinical expertise. In addition to preoperative planning, computer-based approaches can also be used to support surgeons during the course of interventions. In particular, since recent advances in additive manufacturing technology have enabled cost-effective production of patient-and intervention-specific osteotomy instruments, customized interventions can thus be planned for and performed using such instruments. In this chapter, state of the art and future perspectives of computer-assisted deformity-correction surgery of the upper and lower extremities are presented. We elaborate on the benefits and pitfalls of different approaches based on our own experience in treating over 150 patients with three-dimensional preoperative planning and patient-specific instrumentation.

Background: Autologous matrix-induced chondrogenesis (AMIC) has become an interesting treatment option for osteochondral lesions of the talus (OLTs) with promising clinical short- to midterm results. Purpose: To investigate the clinical and radiological outcome of the AMIC procedure for OLTs, extending the follow-up to 8 years. Study Design: Case series; Level of evidence, 4. Methods: Thirty-three patients (mean age, 35.1 years; body mass index, 26.8) with osteochondral lesions of the medial talar dome were retrospectively evaluated after open AMIC repair at a mean follow-up of 4.7 years (range, 2.3-8.0 years). Patients requiring additional surgical procedures were excluded. All OLTs (mean size, 0.9 cm2; range, 0.4-2.3 cm2) were approached through a medial malleolar osteotomy, and 28 patients received subchondral autologous bone grafting. Data analysis included the visual analog scale for pain, the American Orthopaedic Foot and Ankle Society score for ankle function, the Tegner score for sports activity, and the MOCART (magnetic resonance observation of cartilage repair tissue) scoring system for repair cartilage and subchondral bone evaluation. Results: Mean ± SD visual analog scale score improved significantly from 6.4 ± 1.9 preoperatively to 1.4 ± 2.0 at latest follow-up ( P < .001). The mean American Orthopaedic Foot and Ankle Society score was 93.0 ± 7.5 (range, 75-100). The Tegner score improved significantly from 3.5 ± 1.8 preoperatively to 5.2 ± 1.7 at latest follow-up ( P < .001), and 79% returned to their previous sports levels. The MOCART score averaged 60.6 ± 21.2 (range, 0-100). Complete filling of the defect was seen in 88% of cases, but 52% showed hypertrophy of the cartilage layer. All but 1 patient showed persistent subchondral bone edema. The patient’s age and body mass index, the size of the osteochondral lesion, and the MOCART score did not show significant correlation with the clinical outcome. There were no cases of revision surgery for failed AMIC. Fifty-eight percent underwent reoperation, mainly for symptomatic hardware after malleolar osteotomy. Conclusion: AMIC for osteochondral talar lesions led to significant pain reduction, recovery of ankle function, and successful return to sport. The MOCART score did not correlate with the good clinical results; the interpretation of postoperative imaging remains therefore challenging.