Acta Orthopaedica (previously Acta Orthopaedica Scandinavica 1930-2004), owned by the Nordic Orthopaedic Federation, is a non-profit electronic, immediate Open Access journal, meaning your work is free for every-one to access online as soon as it’s published (Gold OA).
Abstracts are presented in PubMed with full text available through PubMed Central. Furthermore, all Acta Orthopaedica content dating back to 1930 is freely available.
The title should include information on the results of the investigation, including the number of patients, average follow-up, and animal or cadaver experiments. Acta prefers titles that are expressive rather than neutral. The first name, middle initial(s), and last name of each author should be given with department affiliations as well as the e-mail of the corresponding author.
The abstract should not exceed 250 words. It should consist of 4 parts: Background and purpose (motive for the study, i.e., why was it done), Patients/material/animals and methods, Results, and Interpretation.
The introduction should focus on the state of knowledge at the beginning of the study. The aims and main hypothesis of the study should be stated clearly. Only in exceptional cases should it exceed 300 words.
Patients/material/animals and methods
The selection of subjects and the inclusion or exclusion criteria should be described. Subjects who declined to participate, withdrawals and those with incomplete follow-up should be accounted for. Describe in detail how the measurements were made and the techniques used.
Ethics, registration, data sharing plan, funding, and potential conflicts of interest
Approval by an Ethics committee, when appropriate, should be stated with date of issue and registration number. Registration applies to registration of clinical trials in for example ClinicalTrials.gov. Give registration number. Data sharing plan applies to clinical trials that began enrolling participants on or after 1 January 2019 which must include a data sharing plan in the trial's registration. Acta encourages data sharing of also other studies. Funding and potential conflicts of interest should be declared.
Do not give the same data in more than 1 way. When summarizing the data, always include measures of variability and the number of subjects. Give the median and range—e.g., 60 years (35–70), the mean and standard deviation—59 years (SD 15), and the frequencies for nominal data. The results of matched data should be given in relevant form (e.g., the distribution of pairwise differences).
Percentages should not be used if the sample size is less than 100. Give percentages with not more than 2 numerals (except 0). Give numbers in digits instead of words, even if n < 10 or at start of sentence (4 instead of four, and 4th instead of fourth).
Present confidence intervals as e.g., 2.2 (CI 0.6–2.4), define 95% confidence interval as CI under "Statistics". Give p-values with only 1 numeral (except 0), e.g., “p-value = 0.893” should be “p-value 0.9”. P-values are unnecessary when confidence intervals are used.
Refrain from meaningless decimals, e.g., rewrite “RR 5.86 (CI 2.03–18.38)” to “RR 6 (CI 2–18)”.
This section should contain a critical discussion of the results—e.g., the quality of the data (selection and information bias) and adequacy of the statistical analysis (confounding bias). It should also assess the relevant literature for or against the findings and if possible, the conclusions as regards clinical application or further research. Discuss, do not recapitulate, your results.
Each table should be self-explanatory, with an adequate title and a logical presentation of the data. Abbreviate words in the columns and explain in footnotes. Each column heading for numerical data should include the unit of measurement. Use SI units. Avoid unnecessary decimals! It is seldom advisable to use more than 2 digits for biologic measurements.
A scanned picture or digital photo should usually be about 85 mm (i.e., 1000 pixels) wide with a resolution of 300 DPI (dots per inch), which gives a square picture an uncompressed file size of 4.5 MiB in color and 1 MiB in grayscale. A black and white drawing or graph may be scanned in 800 DPI bitmap, i.e., 1 bit TIFF. The preferred format is a TIFF-file. The resolution of WEB illustrations (gif) is usually too poor. Color photos should be in CMYK colors.
Highlights, arrows, and letters may be added to digital photos but keep a clean version of the photo for the layout process. Acta prefers to add these as a separate layer.
For digital graphs, use a graphics program that can export vectorized graphs as EMF, EPS, SVG or PDF files. Avoid frames around diagrams, diagrams with perspective drawing, and bar graphs or histograms (use tables). Symbols should be consistent throughout a series of figures. Each axis should be horizontally labeled, with a description of the variable it represents. Axes should be equal in length to make the diagrams quadratic. Use sans serif letters (Arial or Helvetica). Make diagrams in color but avoid complex patterns.
Describe in short what each author did (initials).
Technical help or other help may be acknowledged.
The number of references typically does not exceed 25 (except for meta-analyses or review articles). References should be consecutively numbered and referred to in text by their number within parenthesis. When available, DOI numbers should be added to the references.
For further details regarding references, see https://www.nlm.nih.gov/bsd/uniform_requirements.html#journals.