# AO Surgery Reference vs Ped(z)

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.

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

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 split almost evenly too, at 86% and 85% positive.

AO Surgery Reference ships an update every 6 months, Ped(z) every 6 weeks. The most recent releases landed on September 24, 2026 and September 22, 2026 respectively.

## The numbers

| Metric | AO Surgery Reference | Ped(z) |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.4 (14 ratings)](https://appshunter.io/ios/app/ao-surgery-reference/id403961165/reviews)** | [4.0 (3 ratings)](https://appshunter.io/ios/app/pedz-pediatric-calculator/id498776330/reviews) |
| Number of ratings | **14** | 3 |
| Positive reviews | **85.8% of reviews** | 85.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 6 months | **Every 6 weeks** |
| Monetization | Free | Free |
| Size | 1 MB | 17 MB |
| Requires iOS | 13.0 | **11.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 17+ | 17+ |
| Developer | [AO Foundation](https://appshunter.io/developer/399757056) | [Daniel Gräfe](https://appshunter.io/developer/498769632) |

## What reviewers say

### AO Surgery Reference

[App page](https://appshunter.io/ios/app/ao-surgery-reference/id403961165)

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:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


### Ped(z)

[App page](https://appshunter.io/ios/app/pedz-pediatric-calculator/id498776330)

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:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked 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 24, 2026 and Ped(z) on September 22, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*