['Periosteal adventitia is believed to consist of fibrous tissue without any regenerative potential. This theory results in the assumption that surgically stripped periosteum which is also adventitial has no bone regeneration potential. We decided to test whether the periosteal adventitia is osteoinductive and whether it is suitable for a commonly faced clinical situation in an animal model.', 'This study used 24 femurs from 12 rabbits, which were separated into 3 groups. Lateral femoral condylar cavitary defects were created with a 5 mm drill bit. In group I, the defects were left empty as the control. In group II, the defects were only filled with ceramic graft particles. In group III, the defects were filled with a mixture of ceramic graft particles and autogenous, adventitial, periosteal particles. All animals were sacrificed at the end of the 6th week and were evaluated histologically.', 'The microscopy of 3 different histologists suggested that group III had far superior healing when compared to the control group and group II. The statistical evaluation of the histomorphometrically gathered quantitative results revealed a meaningful increase in woven bone and a decrease in fibrous tissue in group III, confirming the histological analysis.'] Is periosteal adventitia a valuable bone graft alternative?