Social practices are assumed to play an important role in the evolution of new teaching and learning methods. Teachers internalize knowledge developed in their communities through interactions with peers and experts while solving problems or co-creating materials. However, these social practices and their influence on teachers' adoption of new pedagogical practices are notoriously hard to study, given their implicit and informal nature. In this paper, we apply the Knowledge Appropriation Model (KAM) to trace how different social practices relate to the implementation of pedagogical innovations in the classroom, through the analysis of more than 40,000 learning designs created within Graasp, an online authoring tool to support inquiry-based learning, used by more than 35,000 teachers. Our results show how different practices of knowledge appropriation, maturation and scaffolding seem to be related, to a varying degree, to teachers' increased classroom implementation of learning designs. Our study also provides insights into how we can use traces from digital co-creation platforms to better understand the social dimension of professional learning, knowledge creation and the adoption of new practices.