Interdisciplinary orthogeriatric care of older adult hip fracture patients is of growing importance due to an ageing population, yet there is ongoing disagreement about the most effective model of care. This study aimed to compare different forms of orthogeriatric treatment, with focus on their impact on postoperative mobilization, mobility and secondary fracture prevention. In this observational cohort study, patients aged 70 years and older with a proximal femur fracture requiring surgery, were included from 1 January 2016 to 31 December 2019. Data were recorded from hospital stay to 120-day follow-up in the Registry for Geriatric Trauma (ATR-DGU), a specific designed registry for older adult hip fracture patients. Of 23,828 included patients from 95 different hospitals, 72% were female, median age was 85 (IQR 80–89) years. Increased involvement of geriatricians had a significant impact on mobilization on the first day (OR 1.1, CI 1.1–1.2) and mobility seven days after surgery (OR 1.1, CI 1.1–1.2), initiation of an osteoporosis treatment during in-hospital stay (OR 2.5, CI 2.4–2.7) and of an early complex geriatric rehabilitation treatment (OR 1.3, CI 1.2–1.4). These findings were persistent after 120 days of follow-up. Interdisciplinary treatment of orthogeriatric patients is beneficial and especially during in-patient stay increased involvement of geriatricians is decisive for early mobilization, mobility and initiation of osteoporosis treatment. Standardized treatment pathways in certified geriatric trauma departments with structured data collection in specific registries improve outcome monitoring and interpretation.