Comparison

AO Surgery Reference vs Bone Ninja

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

AO Surgery Reference

Access a comprehensive online repository of surgical knowledge for fracture management. It provides detailed guidance on diagnosis, treatment, and aftercare for numerous fracture types, supported by extensive illustrations and expert review.

Highlights
  • 353 fracture types covered
  • 172 surgical approaches
  • 1222 surgical procedures
  • Over 30,000 illustrations
  • Feline, canine, and equine fracture care
  • Powerful search function
Features
Read full description

QUICK ONLINE REFERENCE IN CLINICAL LIFE Gain easy access to the award-winning AO Surgery Reference. AO Surgery Reference is an online repository for surgical knowledge. It describes the complete surgical management process from diagnosis to aftercare for all fractures of a given anatomical region, and also assembles relevant material that the AO has published before. It gives access to:   • aid in surgical decision making for 353 fracture types • 172 approaches • 1222 surgical procedures • all richly illustrated with more than 30'000 Illustrations and much more. To ensure the quality of the content, it is authored, edited, and peer reviewed by experienced AO Faculty from all over the world, some of which are also well-known textbook authors/editors. This is a relaunch of the AO Surgery Reference app utilizing the same responsive user interface that was released February 2020. The highlights are: • Consistent navigational logic and user experience on all screen sizes • Inclusion of feline, canine, and equine fracture care • Combination of Preparation – Approach – Reduction and Fixation – Aftercare into one step called treatment. • Introduction of a powerful search function, allowing simplifications of the user interface as it replaces previous shortcuts.

About

Bone Ninja

This educational tool helps orthopedic surgeons learn to analyze and correct long bone deformities using digital radiographs. It provides tools for measurement, drawing, and simulating osteotomy solutions, based on established surgical methodology.

Highlights
  • Radiograph analysis of bone deformities
  • Digital measurement and drawing tools
  • Osteotomy simulation with cut-out tool
  • Upload and analyze personal radiographs
  • Comparison with suggested correction solutions
  • Educational tool based on established methodology
Features
Read full description

Bone Ninja is a teaching tool developed by two orthopedic surgeons who specialize in limb deformity correction: Dr. Shawn Standard and Dr. John Herzenberg. It is designed to help surgeons learn to analyze long bone deformities. Bone Ninja comes pre-loaded with radiographs of normal legs and deformed legs. You can analyze the provided cases or upload your own. Once your analysis is complete, you can then use the cut-out tool to try different osteotomy solutions. Suggested solutions for the provided cases are available for comparison. Bone Ninja includes tools for drawing lines, measuring angles, measuring lengths, and calibrating the magnification. The cutting tool allows you to manipulate one or more fragments to simulate correction of single or multilevel deformities. The analysis of the radiographs is based on methodology taught at our annual Baltimore Limb Deformity Course (BLDC), now in its 22nd year (DeformityCourse.com). We developed this app to supplement the BLDC and look forward to feedback from attendees and other users. Bone Ninja is not presented as a clinical tool, but rather an educational tool. It will not “automatically” analyze deformities. The student must first learn the methodology of analyzing and planning deformity correction in order to use Bone Ninja. Bone Ninja is a 21st century mobile alternative to pencil, ruler, goniometer, and paper. Bone Ninja will be periodically updated by adding more case examples, more explanations, and more tools. The name “Bone Ninja” is intentionally whimsical and reflects our philosophy of teaching as “infotainment.” Enjoy! Disclaimer The Bone Ninja App is designed for educational purposes only. The intent is to train physicians how to analyze long bone deformities. The Bone Ninja App is not intended to be used for medical diagnosis or treatment. In view of the possibility of human error or changes in medical science, neither the authors nor the developer warrant that the information contained in this software is accurate or complete and they are not responsible for any errors or omissions or the results obtained from the use of such information.

Screenshots

AO Surgery Reference4 screens

Verdict

The call

The clearest difference is price: AO Surgery Reference at Free against Bone Ninja's $49.99. AO Surgery Reference also leads on ratings volume (14 vs 3) and device support (3 vs 1). Bone Ninja's advantage is rating (4.7 vs 4.4) and iOS requirement (8.0 vs 13.0). On review sentiment, update cadence, ads and in-app purchases there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

AO Surgery Reference is free to download; Bone Ninja costs $49.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

Bone Ninja holds the better App Store score, 4.7 against 4.4. Both are backed by a comparable volume of ratings — 14 and 3 respectively. Written reviews point the same way: 86% of AO Surgery Reference's written reviews are positive against 90% of Bone Ninja's.

UpkeepUpdate frequency

AO Surgery Reference ships an update every 6 months, Bone Ninja every 4 months. The most recent releases landed on October 15, 2026 and October 1, 2026 respectively.

Scorecard6 real differences · 4 level
AO Surgery Reference versus Bone Ninja: the parameters behind the verdict, then further details
ParameterAO Surgery ReferenceBone Ninja
PriceFree — better$49.99
Rating4.4 (14 ratings)4.7 (3 ratings) — better
Positive reviews85.8% of reviews90.0% of reviews — better
Number of ratings14 — better3
Update frequencyEvery 6 monthsEvery 4 months — better
AdsNoNo
In-app purchasesNoNo
MonetizationFree — betterPaid
DevicesiPhone, iPad, iPod — betteriPad
Requires iOS13.08.0 — better
Further details — not scored
Size1 MB34 MB
Age rating17+4+
DeveloperAO FoundationLifeBridge Health

Customer experience

AO Surgery Reference

All ratings14 ratings
Positive85.7%
Neutral0.0%
Negative14.3%
Written reviews113 reviews
Positive85.8%
Neutral3.5%
Negative10.6%

Bone Ninja

All ratings3 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews10 reviews
Positive90.0%
Neutral10.0%
Negative0.0%

In-app purchases

None

AO Surgery Reference

No in-app purchases

None

Bone Ninja

No in-app purchases

Questions

Is AO Surgery Reference free?
AO Surgery Reference is free to download, with no in-app purchases.
Is Bone Ninja free?
Bone Ninja costs $49.99, with no in-app purchases.
Which has better reviews, AO Surgery Reference or Bone Ninja?
Bone Ninja is rated higher. AO Surgery Reference averages 4.4 out of 5 from 14 ratings, while Bone Ninja averages 4.7 from 3 ratings.
Do AO Surgery Reference or Bone Ninja have ads?
Neither AO Surgery Reference nor Bone Ninja shows ads.
Which is updated more often, AO Surgery Reference or Bone Ninja?
AO Surgery Reference ships an update every 6 months, and Bone Ninja every 4 months. Most recently, AO Surgery Reference was updated on October 15, 2026 and Bone Ninja on October 1, 2026.

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