Comparison

AO Surgery Reference vs Ped(z)

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

Ped(z)

This medical app provides pediatricians with a comprehensive set of calculators for body percentiles, blood pressure, echocardiography, and more. It supports various calculation methods and guidelines, aiding in accurate patient assessments. Developed by a pediatrician, it serves as a control tool for medical professionals.

Highlights
  • Body percentiles (height, weight, BMI)
  • Blood pressure percentiles
  • Pediatric and fetal echocardiography Z-scores
  • Spirometry normal values
  • Gestational age calculation
  • QTc calculator
  • Hyperbilirubinemia thresholds
Features
Read full description

Helpful pediatric app for pediatricians, developed by a pediatrician. Helps with: • Body percentiles: Calculation of several somatic percentiles (height, weight, head circumference, BMI etc.) according to: - Kromeyer-Hauschild et al. 2001 - Hesse et al. 2016/2017 - Braegger C et al. 2011 (Züricher Longitudinalstudie) - KiGGS study RKI 2013 - WHO Growth Charts - CDC Growth Charts 2000 - Zemel et al 2015 (Mb Down) • Blood Pressure percentiles: Normal values for blood pressure according to: - KiGGS study RKI 2013 - AHA 4. Task Force Report 2005 • Pediatric Echocardiography: Z-Scores for pediatric echocardiography according to: - Gautier et al. 2010 - Kampmann et al. 2000 - Zilberman et al. 2005 - Peterssen et al. 2008 - Dallaire et al. 2011 - Dallaire et al. 2016 - Koestenberger et. al 2009, 2012, 2012, 2014 • Fetal echocardiography: Z-Scores for fetal echocardiography according to: - Lee 2010 • Birth percentiles: Calculation for term and preterm newborns according to: - Voigt et al. 2006 - Fenton TR, Kim JH. A systematic review and meta-analysis to revise the Fenton growth chart for preterm infants. BMC Pediatr. 2013; 13:59 biomedcentral.com/1471-2431/13/59 • Spirometry normal values: Spirometric z-scores and normal values according to: - Quanjer, P.H. et al. 2012 • Kidney percentiles: Z-Scores for ultrasound according to: - Deeg/Weitzel et al. 1997 - Weizel 2012 • Syringe pump: Calculates Dosage or other parameters • Gestational age: No more counting days/weeks in calendars • QTc calculator: Corrected QT interval, QTc, either by RR-Interval or heart rate • Body surface area: BSA according to Mosteller or DuBois • ECG normal values: For Children and adults according to Park MK and Guntheroth WG 2006 • Target height: Estimated target height calculated by their parent's height according to Hermanussen et al 2003 • Hyperbilirubinemia: Thresholds for phototherapy and exchange transfusion according to the german AWMF guideline 024 - 007 DISCLAIMER: No warranty. Use it only as control to your own calculations. Please seek a doctor’s advice in addition to using this app and before making any medical decisions

Screenshots

AO Surgery Reference4 screens
Ped(z)1 screens

Verdict

The call

The clearest difference is rating: AO Surgery Reference at 4.4 against Ped(z)'s 4.0. AO Surgery Reference also leads on ratings volume (14 vs 3). Ped(z)'s advantage is update cadence (every 6 weeks vs every 6 months) and iOS requirement (11.0 vs 13.0). On price, review sentiment, 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

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

AO Surgery Reference holds the better App Store score, 4.4 against 4.0. Both are backed by a comparable volume of ratings — 14 and 3 respectively. Written reviews complicate that: 82% of AO Surgery Reference's written reviews are positive against 85% of Ped(z)'s, so the app with the better star average is not the one people write more warmly about.

UpkeepUpdate frequency

AO Surgery Reference ships an update every 6 months, Ped(z) every 6 weeks. The most recent releases landed on September 18, 2026 and September 22, 2026 respectively.

Scorecard4 real differences · 6 level
AO Surgery Reference versus Ped(z): the parameters behind the verdict, then further details
ParameterAO Surgery ReferencePed(z)
PriceFreeFree
Rating4.4 (14 ratings) — better4.0 (3 ratings)
Positive reviews82.2% of reviews85.0% of reviews — better
Number of ratings14 — better3
Update frequencyEvery 6 monthsEvery 6 weeks — better
AdsNoNo
In-app purchasesNoNo
MonetizationFreeFree
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS13.011.0 — better
Further details — not scored
Size1 MB17 MB
Age rating17+17+
DeveloperAO FoundationDaniel Gräfe

Customer experience

AO Surgery Reference

All ratings14 ratings
Positive85.7%
Neutral0.0%
Negative14.3%
Written reviews45 reviews
Positive82.2%
Neutral4.4%
Negative13.3%

Ped(z)

All ratings3 ratings
Positive66.7%
Neutral0.0%
Negative33.3%
Written reviews20 reviews
Positive85.0%
Neutral0.0%
Negative15.0%

In-app purchases

None

AO Surgery Reference

No in-app purchases

None

Ped(z)

No in-app purchases

Questions

Is AO Surgery Reference free?
AO Surgery Reference is free to download, with no in-app purchases.
Is Ped(z) free?
Ped(z) is free to download, with no in-app purchases.
Which has better reviews, AO Surgery Reference or Ped(z)?
AO Surgery Reference is rated higher. AO Surgery Reference averages 4.4 out of 5 from 14 ratings, while Ped(z) averages 4.0 from 3 ratings.
Do AO Surgery Reference or Ped(z) have ads?
Neither AO Surgery Reference nor Ped(z) shows ads.
Which is updated more often, AO Surgery Reference or Ped(z)?
AO Surgery Reference ships an update every 6 months, and Ped(z) every 6 weeks. Most recently, AO Surgery Reference was updated on September 18, 2026 and Ped(z) on September 22, 2026.

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