77 Years of Hip & Pelvis Surgery.
62,148 Papers. One Living Architecture.
The ONP Knowledge Universe spans 1971–2026 — every major advancement in hip arthroplasty, trauma surgery, metabolic bone disease, pediatric orthopaedics, and beyond, organized into 1,169 evidence threads across 11 pillars and 159 categories. 92.4% of threads carry a defined research gap. This is not a database — it is a living map of what we know and what we don't.
Core Metrics
Live from tree_full_v2.json
Publication Timeline · 1971–2026
2021
Peak year
3,391
Peak papers
×41
Growth 1980→2021
55yr
Corpus span
Thread Maturity Distribution
1,169threads
Gap coverage92.4%
Avg papers/thread53.2
Max papers in thread1,229
Threads with 100+ papers180
Threads per Pillar
Papers per Pillar
Research Gaps per Pillar
Gap Coverage per Pillar % threads with gap
Publication Density by Decade × Pillar
Relative scale — click to exploreDarker cell = more papers in that pillar for that decade (relative to pillar max)
Thread Depth Distribution
Threads exist at 2–6 levels of depth within the taxonomy. Deeper threads are more precisely scoped clinical questions.
Papers Distribution Bands
Pillar Intelligence Map bubble = papers · position = threads
Full Pillar Breakdown
Click any row to drill down| # | Pillar | Threads | Papers | Gaps | Gap% | Categories | Pioneer | Emerging | Established | Avg Papers |
|---|
Top 20 Categories by Thread Count
Corpus Facts
By Era
1970s
524
1980s
2,072
1990s
4,984
2000s
10,531
2010s
22,616
2020s
21,421
Thread Size Percentiles
Median
22 papers
Mean
53.2 papers
P75
~87 papers
P90
~209 papers
Maximum
1,229
The heavy skew (mean 53 vs median 22) reflects the natural power-law of clinical research — a few landmark questions attract most of the literature.
System Completeness
Gap coverage
92.4%
Core questions
~91%
With paper list
100%
Arthroplasty share
48.2%
Threads with DOI-linked papers90.5%
Pioneer threads (frontier)16.2%
Established threads25.4%