Comparison

CongruenceIndexApp vs Bone Ninja Sensei

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

Head to head
About

CongruenceIndexApp

Features
Read full description

Congruence is present when the center of the femoral head (ball) and that of the acetabulum (socket) coincide. Lack of hip congruence between the femoral head and the acetabulum leads to increased local contact stresses, degeneration and consequently to premature arthritis. Although corrective hip osteotomies for the realignment of the dysplastic acetabulum is the main goal of treatment strategies, if the joint space congruency remain fair this end up in failure. Joint congruency can be rated subjectively according to the surgeons experience but according to international literature, evaluation and monitoring hip joint congruency is crucial to judge and predict the outcome of treatment. The App measures objectively the congruence and gives values as percentage (Congruence Index) which can be used for evaluation or comparisons of treatments modalities like acetabular osteotomies in developmental dysplasia or Legg-Calve-Perthes disease of the hip. The CongruenceIndexApp is medical software aimed for orthopaedic surgeons, providing tools that allow doctors to: -Securely import medical images directly from the camera or stored photos -Offers a very convenient and most accurate possibly way to determine joint space congruency with two methods. With transparent circular template-Moses template- you try to find the best-fitted circle superimposed over the femoral head, you mark the femoral head center and with the same manner you locate the acetabular center of the weight bearing zone. When the center of the best-fitted circle of the acetabulum coincide with the center of the femoral head, the concruency of the joint is considered normal (CnI =100%).The app calculates automatically the congruency index. The results are printed as a percentage of congruency of the hip joint and the hip is categorized as normal or abnormal. -Save the planned images, for later review or consultation. Disclaimer All information received from the software output must be clinically reviewed regarding its plausibility before patient treatment! Congruence Index App indicated for assisting healthcare professionals. The app does not provide medical diagnoses or treatment advice. 
The software should be used only for educational purpose. Never use in real Surgery regarding its plausibility, validation is pending. Clinical judgment and experience are required to properly use the software. It only serves as a general guideline. All information received from the software output must be reviewed before any actual attempt. The App indicated for assisting during training. Judgment and experience are required to properly use the App. The software is not for primary image interpretation. Any influence to the operators in making decisions remains Surgeons own responsibility and experience. App does not dispense medical advice. Reference 1. Hartig-Andreasen C, Troelsen A, Thillemann TM, Søballe K. What factors predict failure 4 to 12 years after periacetabular osteotomy? Clin Orthop Relat Res. 2012 Nov;470(11):2978-87 2. Okano K, Enomoto H, Osaki M, Shindo H. Joint congruency as an indication for rotational acetabular osteotomy. Clin Orthop Relat Res. 2009;467:894–900. 3. Matheney Travis, Kim Young-jo, Zurakowski David, Matero Catherine, BA; Millis Michael. Intermediate To Long-term Results Following The Bernese Periacetabular Osteotomy And Predictors Of Clinical Outcome.The Journal Of Bone & Joint Surgery - Scientific Articles: 01 September 2009 - Volume 91 - Issue 9 - p. 2113-2123 4.Murphy S, Deshmukh R. Periacetabular osteotomy: preoperative radiographic predictors of outcome. Clin Orthop Relat Res. 2002; 405:168–174.

About

Bone Ninja Sensei

This educational tool, created by orthopedic surgeons, helps medical professionals learn to analyze long bone deformities. It provides tools for drawing, measuring, and simulating osteotomy solutions on provided or uploaded radiographs.

Highlights
  • Analyze long bone deformities
  • Radiograph analysis tools
  • Simulate osteotomy solutions
  • Upload custom radiographs
  • Drawing and measuring tools
  • Educational case examples
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. Terms of Use and Privacy Policy: https://www.lifebridgehealth.org/main/terms-of-use-and-privacy-policy

Screenshots

CongruenceIndexApp4 screens

Verdict

The call

The clearest difference is price: Bone Ninja Sensei at Free against CongruenceIndexApp's $0.99. Bone Ninja Sensei also leads on update cadence (every 3 months vs every 9 months) and iOS requirement (11.4 vs 18.6). CongruenceIndexApp's advantage is in-app purchases (none vs 1) and device support (3 vs 1). On ads 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

Bone Ninja Sensei is free to download; CongruenceIndexApp costs $0.99 up front. Bone Ninja Sensei sells 1 in-app purchase, starting at $14.99 per year. CongruenceIndexApp asks for nothing beyond the download.

UpkeepUpdate frequency

CongruenceIndexApp ships an update every 9 months, Bone Ninja Sensei every 3 months. The most recent releases landed on October 29, 2026 and October 24, 2026 respectively.

Scorecard5 real differences · 5 level
CongruenceIndexApp versus Bone Ninja Sensei: the parameters behind the verdict, then further details
ParameterCongruenceIndexAppBone Ninja Sensei
Price$0.99Free — better
Rating—3.7 (3 ratings) — better
Positive reviews—25.0% of reviews
Number of ratings—3 — better
Update frequencyEvery 9 monthsEvery 3 months — better
AdsNoNo
In-app purchasesNo — betterYes
Monetization—Free with in-app purchases
DevicesiPhone, iPad, Mac — betteriPad
Requires iOS18.611.4 — better
Further details — not scored
Size1 MB48 MB
Age rating17+4+
DeveloperORTHOPRACTIS.COM SINGLE MEMBER P.C.LifeBridge Health

In-app purchases

None

CongruenceIndexApp

No in-app purchases

1 purchases

Bone Ninja Sensei

Subscriptions1
  • Annual Subscription Plan1 Month trial$14.991 Year

Questions

Is CongruenceIndexApp free?
CongruenceIndexApp costs $0.99, with no in-app purchases.
Is Bone Ninja Sensei free?
Bone Ninja Sensei is free to download, with in-app purchases available.
Do CongruenceIndexApp or Bone Ninja Sensei have ads?
Neither CongruenceIndexApp nor Bone Ninja Sensei shows ads.
Which is updated more often, CongruenceIndexApp or Bone Ninja Sensei?
CongruenceIndexApp ships an update every 9 months, and Bone Ninja Sensei every 3 months. Most recently, CongruenceIndexApp was updated on October 29, 2026 and Bone Ninja Sensei on October 24, 2026.

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