# Total knee polyethylene insert design reference library

Medial congruent (MC), medial pivot / medially stabilized / ball-in-socket, and constrained (varus-valgus constrained, constrained condylar, semi-constrained) inserts, with related hinged, ultracongruent, anterior-stabilized and deep-dish designs tagged separately.

Compiled 2026-09-11.

## Files
- `reference-list.md` – full citation list, grouped by design, with PubMed/DOI/PMC links and a link to each downloaded PDF.
- `reference-list.xlsx` / `reference-list.csv` – same data as a sortable, filterable table (one row per article).
- `open-access-not-downloaded.md` – articles flagged open access whose PDF the publisher would not serve to an automated client; open the link in a browser.
- `pdfs/` – 711 open-access PDFs, named `year_firstauthor_PMIDnnn.pdf`.

## Method
1. PubMed/MEDLINE searched with 47 term sets covering: medial congruent / medially congruent; medial pivot, medial(ly) stabilized, ball-in-socket, ball-and-socket, medial ball, medial spherical; constrained condylar, condylar constrained, varus-valgus constrained, constrained insert/polyethylene/liner, semi-constrained, CCK, LCCK, TC3; rotating hinge and hinged knee; ultracongruent, deep dish, anterior-stabilized, highly congruent/conforming; brand names (GMK Sphere, Persona MC, SAIPH, Journey II, Evolution Medial Pivot, Physica KR, Attune); and generic insert/bearing design terms. 3,279 unique records retrieved.
2. Title, abstract, keywords and MeSH were screened for a knee arthroplasty context and for the target design terms. Hip, shoulder and other joints were excluded. Records that mention constraint only generically (e.g. "a constrained implant was used") are kept but placed in a separate related section so they can be filtered out.
3. Open-access status and PDF locations were taken from Europe PMC and OpenAlex. PDFs were downloaded from PubMed Central / Europe PMC first, then from publisher or repository open-access links, and each file was verified to be a real PDF.

## Columns in the spreadsheet
section, year, citation (Vancouver style), title, authors, journal, volume, issue, pages, doi, pmid, pmcid, approaches (which design terms appear), pub_types (RCT, meta-analysis, review, etc.), language, subject (blank = human clinical; else animal or cadaveric), oa_status, oa_source (gold/green/bronze/hybrid), pdf_file, pdf_source, cited_by (OpenAlex citation count), pubmed_url, doi_url, pmc_url.

## Caveats
- Coverage is PubMed/MEDLINE only.
- Non-English articles are included when indexed; titles appear in English translation in square brackets.
- "Subscription / not open access" means no legal free copy was found by Europe PMC or OpenAlex, not that none exists.