CongruenceIndexApp

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.
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. Clinical judgment and experience are required to properly use the software. The software is not for primary image interpretation.
In a busy everyday practice measuring in X-rays in clinical settings it is time consuming and cumbersome. Accessory instruments like protractors, goniometers, well sharped pencils, rulers or even transparent papers must be available. The app offers a very convenient and accurate way to measure the value of congruence by clicking points, right over your iPhone or iPad and help decide what could be considered normal or pathologic.
The app is not a simple goniometer, is an enhanced product which help to monitor objectively during the course of the treatment how much hip joint concruency is achieved. This App is particular useful especially in clinical settings where you need a quick results. Please see tutorial videos at the developer’s web site.

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.