--- a
+++ b/dosma/tissues/__init__.py
@@ -0,0 +1,12 @@
+from dosma.tissues import femoral_cartilage, meniscus, patellar_cartilage, tibial_cartilage
+from dosma.tissues.femoral_cartilage import *  # noqa
+from dosma.tissues.meniscus import *  # noqa
+from dosma.tissues.patellar_cartilage import *  # noqa
+from dosma.tissues.tibial_cartilage import *  # noqa
+from dosma.tissues.tissue import *  # noqa
+
+__all__ = []
+__all__.extend(femoral_cartilage.__all__)
+__all__.extend(meniscus.__all__)
+__all__.extend(patellar_cartilage.__all__)
+__all__.extend(tibial_cartilage.__all__)