Comparison

AO Surgery Reference vs OrthoBMI

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

OrthoBMI

This medical tool calculates patient target weights for specific BMI thresholds, crucial for orthopedic surgery planning. It offers a fast, clinic-ready interface to determine BMI from actual weight or estimate weight needed to reach surgical BMI goals.

Highlights
  • BMI calculator for orthopedic and surgical use
  • Calculate target weight for BMI thresholds
  • Determine BMI from actual weight
  • Automatic outputs at BMI 35, 40, 45, and 50
  • Integrated BMI guidance for surgery
  • Optimized for iPhone and iPad
Features
Read full description

OrthoBMI is a clinical BMI calculator designed for orthopedic surgery and joint replacement planning. Calculate patient weight at key BMI thresholds or determine BMI from actual weight using a fast, clinic-ready interface. Enter height to generate: • Target weight for BMI thresholds • Actual weight for BMI calculation Target weight represents the body weight a patient would need to reach a specific BMI threshold at their current height. It is presented as a practical estimate that accounts for normal day-to-day weight fluctuations, supporting realistic goal setting and preoperative planning. Features: • BMI calculator for orthopedic and surgical use • Toggle between target weight and actual weight calculations • Automatic outputs at BMI 35, 40, 45, and 50 • Optimized for iPhone and iPad • Integrated BMI guidance for surgery OrthoBMI supports efficient, consistent BMI-based discussions in clinic. This BMI calculator is intended for clinical support and informational use only and does not replace medical judgment.

Screenshots

AO Surgery Reference4 screens
OrthoBMI4 screens

Verdict

The call

The clearest difference is price: AO Surgery Reference at Free against OrthoBMI's $0.99. AO Surgery Reference also leads on device support (3 vs 1) and iOS requirement (13.0 vs 26.2). OrthoBMI's advantage is rating (5.0 vs 4.4) and update cadence (every 5 days vs every 6 months). On ratings volume, 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; OrthoBMI costs $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

OrthoBMI holds the better App Store score, 5.0 against 4.4. Both are backed by a comparable volume of ratings — 14 and 6 respectively. Written reviews point the same way: 86% of AO Surgery Reference's written reviews are positive against 100% of OrthoBMI's.

UpkeepUpdate frequency

AO Surgery Reference ships an update every 6 months, OrthoBMI every 5 days. The most recent releases landed on October 23, 2026 and October 15, 2026 respectively.

Scorecard7 real differences · 3 level
AO Surgery Reference versus OrthoBMI: the parameters behind the verdict, then further details
ParameterAO Surgery ReferenceOrthoBMI
PriceFree — better$0.99
Rating4.4 (14 ratings)5.0 (6 ratings) — better
Positive reviews85.8% of reviews100.0% of reviews — better
Number of ratings14 — better6
Update frequencyEvery 6 monthsEvery 5 days — better
AdsNoNo
In-app purchasesNoNo
MonetizationFree — betterPaid
DevicesiPhone, iPad, iPod — betteriPhone
Requires iOS13.0 — better26.2
Further details — not scored
Size1 MB2 MB
Age rating17+4+
DeveloperAO FoundationTHOMAS WARD GILL JR

Customer experience

AO Surgery Reference

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

OrthoBMI

Written reviews4 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

AO Surgery Reference

No in-app purchases

None

OrthoBMI

No in-app purchases

Questions

Is AO Surgery Reference free?
AO Surgery Reference is free to download, with no in-app purchases.
Is OrthoBMI free?
OrthoBMI costs $0.99, with no in-app purchases.
Which has better reviews, AO Surgery Reference or OrthoBMI?
OrthoBMI is rated higher. AO Surgery Reference averages 4.4 out of 5 from 14 ratings, while OrthoBMI averages 5.0 from 6 ratings.
Do AO Surgery Reference or OrthoBMI have ads?
Neither AO Surgery Reference nor OrthoBMI shows ads.
Which is updated more often, AO Surgery Reference or OrthoBMI?
AO Surgery Reference ships an update every 6 months, and OrthoBMI every 5 days. Most recently, AO Surgery Reference was updated on October 23, 2026 and OrthoBMI on October 15, 2026.

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