Pavlik Harness research reaches milestone – Updates from Dr. Price

Pavlik Harness research reaches milestone – Updates from Dr. Price

The IHDI has reached an important milestone with the publication of our first research study.  This study was fully funded by donations, in the effort to cure hip dysplasia. The IHDI teamed up with the mechanical and aerospace engineering department at the University of Central Florida – who is a world leader in computer simulation technology.

The official scientific abstract is listed below for your reference, however it sounds like a complicated outer-space project. What the IHDI doctors did, was work with highly recognized engineers to create a simulation model of a baby in a Pavlik Harness.  That computer model was medically validated with MRIs, CT Scans and anatomical studies of dislocated hips.

Then, a peer review was done before publication in the highly respected Journal of Biomechanics. Peer review means that several independent and highly qualified scientists made sure that this model was developed correctly and that the information was reliable and accurate.

In the coming years, we plan to further refine the model so we can modify harness strap positions, leg positions, and other factors to see if we can reduce the hips in more difficult situations. So far, we’ve identified some new findings about why the difficult ones don’t reduce, but we need to quantify appropriate changes in the harness.

Until now, modifications and adjustments of the harness have been based on experience of the physician, but now we can begin to put some science behind it.

Also, Julie Zielinski, M.D. is joining our team from afar and will come to Orlando, FL three times a year to review and collaborate. She is a young pediatric orthopedic surgeon at University of Tennessee with a mechanical engineering degree and two years of experience with General Motors in their crash test division before going to medical school. Her earlier publications form the basis for most of the car seat restraints of children in spica casts, so DDH is a special interest for Dr. Zielinski.

As you might imagine, research is a slow and tedious process. This particular research has been underway for over three years and has required $90,000 of IHDI Funds even though our doctors, the professors at University of Central Florida, and their graduate students have contributed hundreds of hours of time at no cost. This was money well spent because this allowed us to secure a $340,000 grant from the National Science Foundation to continue the work, make it more detailed, and find new ways to make the Pavlik Harness more successful.  Plus, we will have new ways to teach others how to use the Harness effectively in difficult cases.

Any of you who have contributed to IHDI and especially Larry the Cable Guy’s Git-R-Done Foundation can be proud of this achievement and many more to come!

Thank you for your continued support in our mission against hip dysplasia.

Charles T. Price, M.D.


J Biomech. 2013 May 31;46(9):1501-7.

Mechanics of hip dysplasia reductions in infants using the Pavlik harness: A physics-based computational model.

Ardila OJ, Divo EA, Moslehy FA, Rab GT, Kassab AJ, Price CT.


Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, FL 32816, United States.


Biomechanical factors influencing the reduction of dislocated hips with the Pavlik harness in patients of Developmental Dysplasia of the Hip (DDH) were studied using a three-dimensional computer model simulating hip reduction dynamics in (1) subluxated and (2) fully dislocated hip joints. Five hip adductor muscles were identified as key mediators of DDH prognosis, and the non-dimensional force contribution of each in the direction necessary to achieve concentric hip reductions was determined. Results point to the adductor muscles as mediators of subluxated hip reductions, as their mechanical action is a function of the degree of hip dislocation. For subluxated hips in abduction and flexion, the Pectineus, Adductor Brevis, Adductor Longus, and proximal Adductor Magnus contribute positively to reduction, while the rest of the Adductor Magnus contributes negatively. In full dislocations all muscles contribute detrimentally to reduction, elucidating the need for traction to reduce Graf IV type dislocations. Reduction of dysplastic hips was found to occur in two distinct phases: (a) release phase and (b) reduction phase.