Objectives To assess across seven hospitals from six different countries the extent to which the COVID-19 pandemic affected the volumes of orthopaedic hospital admissions and patient outcomes for non-COVID-19 patients admitted for orthopaedic care. Design A multi-centre interrupted time series (ITS) analysis. Setting Seven hospitals from six countries who collaborated within the Global Health Data@Work collaborative. Participants Non-COVID-19 patients admitted for orthopaedic care during the pre-pandemic (January/2018-February/2020) and COVID-19 pandemic (March/2020-June/2021) period. Admissions were categorised as: (1) acute admissions (lower limb fractures/neck of femur fractures/pathological fractures/joint dislocations/upper limb fractures); (2) subacute admissions (bone cancer); (3) elective admissions (osteoarthritis). Outcome measures Monthly observed versus expected ratios (O/E) were calculated for in-hospital mortality, long (upper-decile) length-of-stay and hospital readmissions, with expected rates calculated based on case-mix. An ITS design was used to estimate the change in level and/or trend of the monthly O/E ratio by comparing the COVID-19 pandemic with the pre-pandemic period. Results 69 221 (pre-pandemic) and 22 940 (COVID-19 pandemic) non-COVID-19 orthopaedic patient admissions were included. Admission volumes were reduced during the COVID-19 pandemic for all admission categories (range: 33%-45%), with more complex patients treated as shown by higher percentages of patients admitted with ≥1 comorbidity (53.8% versus 49.8%, p<0.001). The COVID-19 pandemic was not associated with significant changes in patient outcomes for most diagnostic groups. Only for patients diagnosed with pathological fractures (pre-pandemic n=1671 and pandemic n=749), the COVID-19 pandemic was significantly associated with an immediate mortality reduction (level change of -77.7%, 95% CI -127.9% to -25.7%) and for lower limb fracture patients (pre-pandemic n=9898 and pandemic n=3307) with a significantly reduced trend in readmissions (trend change of -6.3% per month, 95% CI -11.0% to -1.6%). Conclusions Acute, subacute, as well as elective orthopaedic hospital admissions volumes were reduced in all global participating hospitals during the COVID-19 pandemic, while overall patient outcomes for most admitted non-COVID-19 patients remained the same despite the strain caused by the surge of COVID-19 patients. @en