Comparison

AO Surgery Reference vs SpinopelvicBalanceApp

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
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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

SpinopelvicBalanceApp

Features
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The assessment of the parameters involved in spinopelvic jucture are of paramount importance for spine and joint replacement surgeon. The dynamic interplay between flexibility and balance around the axis of gravity determine the type and the amount of influence in spine and hips. Radiographic parameters to evaluate objectively the spinopelvic sagittal balance are Pelvic incidence (PI), Sacral slope (SS), Pelvic Tilt (PT), Lumbar lordosis (LL). Drawings in patients X-rays and precise measurements are important in order to quantify the magnitude of spinal deformities, to monitor the success or failure of treatment and thus optimise the management of patients according to the severity of the imbalance or even to identify patient at risk of degenerative spondylolisthesis or disk herniation. The Spinopelvic Balance App is medical software aimed for orthopaedic surgeons, providing tools that allow doctors to: -Securely import medical images directly from the camera or stored photos. -By marking few points at the image of X-ray, the App calculates and offers a very convenient way to determine the most accurate possibly way at once, Pelvic incidence (PI), Sacral slope (SS), Pelvic Tilt (PT), Lumbar lordosis (LL), thoracic kyphosis, PI–LL Pelvic incidence Angle (PI) minus Lumbar lordosis Angle (LL) PI–LL, theoretical normal pelvic tilt (tPT),theoretical normal L1-S1 lumbar lordosis (tL1S1), Pelvic Radius Angle (PRA). According to measured parameters the app categorises the severity of the imbalance of spine, in different stages: optimal or non optimal. -Save the planned images, for later review or consultation.The measured values are compared by normal reference databases and also data are exported as txt file, ready to print or to input as cells to excel for research. -The app allows choosing between simple and extended method according to everyday preference and also by choosing points in vertebra body in a independent manner from order. -The app can be used to measure L5 Incidence (L5I) Angle or L4 respectively. -The app offers theoretical value estimation this is particularly useful because a sensible difference between theoretical value and measured value reveals a compensation phenomenon if the pelvis tilt (PT) is higher than its theoretical value, then it is due to pelvis retroversion, which is a compensation phenomenon. Knowing the theoretical value of Pelvis Tilt (PT) provided it is easy to understand that a sensible difference between theoretical value and measured value is a compensation phenomenon. All information received from the software output must be clinically reviewed regarding its plausibility before patient treatment! Spinopelvic Balance App indicated for assisting healthcare professionals. Clinical judgment and experience are required to properly use the software.The software is not for primary image interpretation. In a busy everyday practice, the examiner have to draw lines in X-rays or in clinical settings, this it is time consuming and cumbersome. Accessory instruments like protractors, hinged goniometers, well sharped pencils, rulers or even transparent papers must be available. The app offers a very convenient and accurate way to perform most common radiographic measurements for spine, at the spinopelvic juncture in a blink of an eye in front of your screen. The build in feature of the app, allows results to be categorized may help decide what could be considered normal or pathologic. The app is not a simple goniometer, is an enhanced product which helps to monitor objectively the course of the treatment and evaluate optimally the spine. This App is particular useful in clinical settings where you need a quick results without losing time.Please see tutorial videos at the developer’s web  Reference  1.Nunes VR, et al.Spinopelvic balance evaluation of patients with degenerative spondylolisthesis L4L5 and L4L5 herniated disc who underwent surgery.Rev Bras Ortop. 2016 Sep 22;51(6):662-666.

Screenshots

AO Surgery Reference4 screens
SpinopelvicBalanceApp4 screens

Verdict

The call

The clearest difference is price: AO Surgery Reference at Free against SpinopelvicBalanceApp's $8.99. AO Surgery Reference also leads on iOS requirement (13.0 vs 15.4). On update cadence, ads, in-app purchases and device support 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; SpinopelvicBalanceApp costs $8.99 up front. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

AO Surgery Reference ships an update every 6 months, SpinopelvicBalanceApp every 9 months. The most recent releases landed on October 23, 2026 and October 26, 2026 respectively.

Scorecard2 real differences · 8 level
AO Surgery Reference versus SpinopelvicBalanceApp: the parameters behind the verdict, then further details
ParameterAO Surgery ReferenceSpinopelvicBalanceApp
PriceFree — better$8.99
Rating4.4 (14 ratings) — better—
Positive reviews85.8% of reviews—
Number of ratings14 — better—
Update frequencyEvery 6 months — betterEvery 9 months
AdsNoNo
In-app purchasesNoNo
MonetizationFree—
DevicesiPhone, iPad, iPodiPhone, iPad, iPod, Mac — better
Requires iOS13.0 — better15.4
Further details — not scored
Size1 MB1 MB
Age rating17+17+
DeveloperAO FoundationORTHOPRACTIS.COM SINGLE MEMBER P.C.

In-app purchases

None

AO Surgery Reference

No in-app purchases

None

SpinopelvicBalanceApp

No in-app purchases

Questions

Is AO Surgery Reference free?
AO Surgery Reference is free to download, with no in-app purchases.
Is SpinopelvicBalanceApp free?
SpinopelvicBalanceApp costs $8.99, with no in-app purchases.
Do AO Surgery Reference or SpinopelvicBalanceApp have ads?
Neither AO Surgery Reference nor SpinopelvicBalanceApp shows ads.
Which is updated more often, AO Surgery Reference or SpinopelvicBalanceApp?
AO Surgery Reference ships an update every 6 months, and SpinopelvicBalanceApp every 9 months. Most recently, AO Surgery Reference was updated on October 23, 2026 and SpinopelvicBalanceApp on October 26, 2026.

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