BackgroundIt is well-known that exercise through sports and physical activity has beneficial effects on health. After lower extremity amputation, low rates of participation in sports activities have been shown. So far, there is only limited scientific long-term information concerning sports activity and feasible types of sports in patients with lower extremity amputations due to malignant tumors. This study sought to provide very long-term information about the following questions: (1) What sports activity levels can be achieved after lower extremity amputation due to a malignant tumor? (2) What are feasible types of sports? (3) Is the University of California Los Angeles (UCLA) Activity Score influenced by patient's age, the age at the time of surgery and the amount of prosthesis sockets used to date? HypothesisPatients with lower extremity amputation due to a malignant tumor cannot regularly participate in moderate sports activities (UCLA Activity Score≥6) in the very long term. Materials and methodsIn a retrospective questionnaire survey, 21 former patients (seven females, 14 males; median age: 60.5 years [range, 33–74]) who underwent an amputation of the lower extremity (14 transfemoral, four knee disarticulations, three transtibial) from 1961 to 1993 due to a malignant tumor were interviewed. The median follow-up was 41.1 years (range, 23–55). The patients were interviewed about types of sports, frequencies and durations of sports sessions at the time of the last follow-up, as well as retrospectively. Sports activity levels were then assessed based on the UCLA Activity Score. Demographic background, data on amputation level, histological results, prosthetic devices and revision surgeries were collected. ResultsSeven patients (33%) were still regularly exercising at least moderate sports activities at the last follow-up, including one patient regularly participating in impact sports. The preoperative median UCLA Activity Score of 9 (range, 2–10) decreased to 5 (range, 2–10) at the last follow-up (p<0.001). Swimming (13 patients, seven on a regular basis), cycling (seven), downhill skiing (five) and hiking (four) were among the most common feasible types of sports. Increasing age had a negative influence on the UCLA Activity Score (95% CI (−0.034, −0.006); RB=−0.020; SD=0.0074; p=0.007). ConclusionAfter a major amputation in the lower extremity due to a malignant tumor, high activity levels by practicing types of sports such as downhill skiing, are achievable. In the very long term, a regular participation in at least moderate activities, such as swimming, is possible. Programs for physical and sports activities, based on recommendations drawn from long-term experience, are necessary and should be individually tailored to amputees and their limitations. Level of evidenceIV.