imedslab/mrkr-knee-alignment

Lower-limb Alignment Measurements for the MRKR Subset

Anonymised knee radiograph metadata with manual and derived radiographic alignment measurements for a subset of the Emory Knee Radiograph (MRKR) dataset [1]. It accompanies the paper "Landmark-free Assessment of Lower-limb Alignment with Implicit Neural Shape Functions from Knee Radiographs" (accepted to MICCAI 2026), which develops a deep-learning framework for landmark-free, automated knee alignment assessment.

Release file: data/metadata_with_measurements_final.csv — 402 rows, 14 columns, 244 unique anonymised patient IDs.

Dataset Details

The dataset provides three angular alignment measurements: aTFA — anatomical tibiofemoral angle, formed by the anatomical axes of the femur and tibia. aMPTA — anatomical medial proximal tibial angle, formed by the anatomical tibial axis and the tibial joint line (medial side). JLCA — joint line convergence angle, formed by the femoral and tibial joint lines. A single board-certified radiologist recorded absolute aTFA, acute aMPTA, and absolute JLCA over two reading rounds 7–10 days apart, with the second reading blinded to the first; per-round values (_r1, _r2) and their mean (_mean) are provided. Only the de-identified measurement/metadata table is released, not the images.

• Curated by: Zhisen Hu, Antti Kemppainen, David Johnson, Egor Panfilov, Huy Hoang Nguyen, Timothy Cootes, Claudia Lindner, Aleksei Tiulpin
• Language(s): English (en) — column labels and textual metadata
• Modality / format: Tabular knee radiograph metadata and measurements (CSV)
• License: CC BY-NC 4.0
• Paper: Hu et al., arXiv:2606.15250 (accepted to MICCAI 2026, poster)
• Source images: Emory Knee Radiograph (MRKR) dataset [1]
• Repository / Contact: [More Information Needed]

Uses

Direct use (non-commercial research and education): alignment-measurement research (aTFA, aMPTA, JLCA), osteoarthritis imaging-metadata analysis, model development and evaluation, and intra-rater reliability studies using the _r1/_r2/_mean columns.

Out-of-scope: clinical decision-making, diagnosis, or treatment; commercial use without prior written permission; and population-level or epidemiological inference (this is a randomly drawn subset).

Dataset Structure

Single CSV (402 × 14); column-level definitions in docs/DATA_DICTIONARY.md. Key fields:

• empi_anon — anonymised patient identifier. Bilateral studies were split into separate left and right knees, so a patient may contribute two rows; this is why 402 knees map to 244 unique IDs.
• laterality — knee side (left / right).
• aTFA_r1, aTFA_r2, aTFA_mean — absolute anatomical tibiofemoral angle.
• aMPTA_r1, aMPTA_r2, aMPTA_mean — acute anatomical medial proximal tibial angle.
• JLCA_r1, JLCA_r2, JLCA_mean — absolute joint line convergence angle.

Remaining columns are DICOM / image-derived metadata (see the data dictionary). Splits: none defined. Missing values: 15 rows are missing several DICOM / image metadata fields.

Dataset Creation

The 402 knees were randomly selected from the MRKR dataset [1], comprising both bilateral and unilateral studies. Bilateral studies were split into individual knees. A single board-certified radiologist measured aTFA, aMPTA, and JLCA on two occasions 7–10 days apart, with the second reading blinded to the first, to enable intra-rater consistency assessment; _r1 and _r2 hold the two readings and _mean their average. The data is de-identified (only empi_anon plus DICOM/image metadata) and was released with approval from the relevant data owner, supervisor, or institution.

Bias, Risks, and Limitations

Measurements come from a single rater (supporting intra- but not inter-rater analysis) and are subject to manual variability. The accompanying paper reports the MRKR subset as roughly 40% White and 40% African American patients, so it represents a specific cohort and may not generalise to other populations; 15 rows also have missing metadata. Use for non-commercial research and education only; do not use for clinical decision-making.

Citation

You must cite the following paper (accepted to MICCAI 2026):

@inproceedings{hu2026landmark,
  title={Landmark-free Assessment of Lower-limb Alignment with Implicit Neural Shape Functions from Knee Radiographs},
  author={Hu, Zhisen and Kemppainen, Antti and Johnson, David and Panfilov, Egor and Nguyen, Huy Hoang and Cootes, Timothy and Lindner, Claudia and Tiulpin, Aleksei},
  booktitle={International Conference on Medical Image Computing and Computer-Assisted Intervention (MICCAI)},
  year={2026},
  organization={Springer}
}

APA: Hu, Z., Kemppainen, A., Johnson, D., Panfilov, E., Nguyen, H. H., Cootes, T., Lindner, C., & Tiulpin, A. (2026). Landmark-free assessment of lower-limb alignment with implicit neural shape functions from knee radiographs. In Medical Image Computing and Computer-Assisted Intervention (MICCAI). Springer.

Glossary

aTFA — anatomical tibiofemoral angle; aMPTA — anatomical medial proximal tibial angle; JLCA — joint line convergence angle; _r1/_r2 — first/second reading rounds (7–10 days apart); _mean — mean of the two; empi_anon — anonymised patient identifier.

Reference

[1] Price BJ, Gichoya J, Chavoshi M, Adleberg J, Thomas K, Zaiman Z, Mansuri A, Brown-Mulry B, Okechukwu C, Dapamede T, Li F, Isaac RS, Goltzer O, Gottschalk M, Trivedi H. The Emory Knee Radiograph (MRKR) Dataset. J Imaging Inform Med. 2026 Mar 10. doi: 10.1007/s10278-026-01902-6. Epub ahead of print. PMID: 41807882.