Acute and chronic aspects of hindfoot trauma

In Chapter 1, talar osteochondral lesions in patients with unstable ankle fractures were investigated. Ten percent of investigated ankle fractures had osteochondral lesions on postoperative CT. In Chapter 2, bottoming of osteochondral autografts was investigated in the ovine model. Unbottomed grafts had more graft subsidence than bottomed ones and subsidence subsequently lead to worse histological healing. In Chapter 3, healing of osteochondral defects was investigated in the ovine animal model. Osteochondral defect healing started with subchondral bone plate restoration. At six months, defect closure was incomplete and irregular. In Chapter 4, the most accurate radiographic method to determine talar three-dimensional position in varus and valgus osteoarthritic ankles was assessed. The frontal tibiotalar surface angle, sagittal talocalcaneal inclination angle, and horizontal talometatarsal I angle were found most suitable. In Chapter 5, the three-dimensional position of the talus in the weightbearing varus and valgus osteoarthritic ankle joint was determined. 67% of varus ankles and 48% of valgus ankles had an additional malalignment in the sagittal and/or horizontal plane. In Chapter 6, fracture reduction in the sinus tarsi approach for intra-articular calcaneal fractures was assessed by using CT. 64% of patients had good to excellent posterior facet reduction, with no loss of reduction at follow-up. Finally, in Chapter 7, a systematic review and meta-analysis showed that the risk of developing a wound infection decreased with as much as 80% when the sinus tarsi was used, compared to the conventional extended lateral approach.