Sponsored Research and Clinical Trials

PLEASE NOTE, IHDI -funded research grants do not provide for institutional overheads and/or indirect costs of research.

Current Research

Scientific Publications

Research Promoted by IHDI


Current Research

IHDI Classification of Hip Dysplasia

A new classification of hip dysplasia was developed by the International Hip Dysplasia Institute (IHDI). This Classification has been validated and was recently published in the Journal of Pediatric Orthopedics. The value of any classification system is so that doctors can compare similar cases and identify treatments for mild cases that may be different from treatments for severe cases. Classification of types of hip dysplasia also allows comparisons between medical centers because some centers may have more of the mild cases while other centers may have more of the severe cases. Comparing similar cases can identify those centers with the best results so we can learn from that experience.

The IHDI Classification grades severity from Grade 1 as the mildest type to Grade 4 as the most severe type of hip dislocation. There are other ways to classify hip dysplasia, but the IHDI Classification has been proven more reliable and more accurate than the older classification methods. With your financial help, the International Hip Dysplasia Institute supports detailed comparison of treatments and results at eight major pediatric medical centers around the world. This is only possible because of the internet and because of computerized data collection. The IHDI is using the latest technology to conduct this massive research project. Over the past three years the IHDI has recorded the largest number of newborn hip dislocations that have ever been identified. We are tracking these patients and carefully analyzing the differences in grade, treatment and outcome. It takes about 10 years for research to make meaningful discoveries that are reliable. However, the IHDI Classification is a big step in the right direction so doctors at IHDI and elsewhere can make meaningful comparisons. Thank you for your support. Download (PDF, 7.7MB) – See more at: https://hipdysplasia.org/news/just-published-ihdi-classification-of-hip-dysplasia/#sthash.ppDhk8mC.dpuf

3-D Computer Simulation Project with the University of Central Florida

This is a long-term collaborative project between the IHDI and the University of Central Florida’s College of Engineering to develop a 3-dimensional computer simulation model. This model will allow researchers to gain a better understanding of how various hip dysplasia treatments and positions affect the hips. Studies utilizing this model are listed below:

Analysis and Optimization of the Pavlik Harness Treatment of Neonates with Hip Dysplasia

The study aims to better the current understanding of how the Pavlik Harness works on baby’s hips when being treated for developmental dysplasia of the hip. The goal is to increase positive outcomes for the Pavlik Harness as a treatment method, improve hip dysplasia treatment without surgery and to better understand why the harness fails in some cases.

3-Dimensional orientation of the Iliopsoas tendon in healthy and dysplastic hips in the full range of hip abduction and flexion

This is a study conducted by Arnold Palmer Hospital and the University of Central Florida to determine whether the tendon of a large hip muscle, the iliopsoas, prevents closed reduction of Developmental Dysplasia of the Hip. It is commonly assumed that this muscle is contracted and sometimes interferes with reduction of the hip into the socket. The 3-D computer simulation model will be used along with anatomy dissections and analysis of MRI and CT findings of infants in casts following closed reduction. The hypothesis is that this muscle is not an obstacle to reduction as commonly assumed. Demonstration of the effect or lack of effect of this muscle will help doctors focus their attention to the major obstacles that prevent closed reduction in dislocated hips so that improved methods of reduction may be developed. Basic information like this is needed in order to propose new solutions for treatment of hip dysplasia.

Prospective Observational Cohort Study of Children with Hips Dislocated at Rest

This is a five-year project to compare treatment methods commonly used at the major medical centers of our affiliate sites. No new or investigative treatments are being introduced. The purpose of this study is to record and compare the results from a wide group of experienced pediatric orthopedic surgeons to determine whether our experiences are similar or different. This study has been under development for two years and is now beginning to collect data for comparison purposes. All patients are fully informed and voluntarily consent to have their case recorded in detail for comparison purposes. All human subject research policies have been followed rigorously, This project has been reviewed and approved by investigational oversight committees in five different countries.

Scientific Publications


  • Narayanan U, Mulpuri K, Sankar WN, Clarke NM, Hosalkar H, Price CT; International Hip Dysplasia Institute Study Group. “Reliability of a New Radiographic Classification for Developmental Dysplasia of the Hip.” J Pediatr Orthop. 2014 Sep 26. [Epub ahead of print]
  • Clohisy JC, Baca G, Zaltz I, Larson CM, Trousdale RT, Kim Y-J, Sucato DJ, Sink EL, Podeszwa DA, Millis MB, Beaule PE, Schoenecker PL, Sierra RJ.  Descriptive Epidemiology of Femoroacetabular Impingement: A North American Cohort. (ahead of print: Am J Sports Med 2013).
  • Price CT, Ramo BA. Prevention of hip dysplasia in children and adults. Orthop Clin North Am. 2012 Jul;43(3):269-79.
  •  Clarke NM, Castaneda P. Strategies to improve nonoperative childhood management. Orthop Clin North Am. 2012 Jul;43(3):281-9.
  •  Wedge JH, Kelley SP. Strategies to improve outcomes from operative childhood management of DDH. Orthop Clin North Am. 2012 Jul;43(3):291-9.
  •  Price CT. Swaddling and Hip Dysplasia: New Observations: Commentary on an article by Enbo Wang, MD, PhD, et al.: “Does Swaddling Influence Developmental Dysplasia of the Hip? An Experimental Study of the Traditional Straight-Leg Swaddling Model In Neonatal Rats.” J Bone Joint Surg. Am.  Jun 2012; 94 (12); e92 1-2. doi: 10.2106 /JBJS.L.00297
  • Williams N, Foster BK, Cundy PJ. Is swaddling damaging our babies’ hips? [Letter to the Editor] MJA Sep 2012: 197 (5).
  • Ardila OJ, Divo EA, Moslehy FA, Rab GT, Kassab AJ, Price CT. Mechanics of hip dysplasia reductions in infants using the Pavlik harness: A physics-based computational model. J Biomech 46(9):1501-7, 2013. doi: 10.1016/j.jbiomech.2013.03.031. Epub 2013 Apr 28.

 Manuscripts in Preparation or Submitted

  • Duncan S, Clohisy JC, Baca G, Zaltz I, Sucato DJ, Podeszwa DA, Trousdale RT, Sierra RJ, Beaule PE, Millis MB, Kim Y-J, Sink EL, Schoenecker PL. Epidemiology of Developmental Dysplasia of the Hip: A North American Cohort.
  • Clohisy JC, Nepple JJ, Larson CM, Zaltz I, Millis MB, ANCHOR. What are the Reasons for Hip Preservation Surgery after Prior Hip Procedures?
  • Nepple JJ, Martel JM, Kim Y-J, Zaltz I, Hosalkar HS, Millis MB, Podeszwa DA, Sink EL, Sucato DJ, Clohisy JC. The Reliability of Computer-Assisted Measurement of Young Adult Hip Disease.
  • Clohisy JC, Baca G, Zaltz I, Sucato DJ, Podeszwa DA, Trousdale RT, Sierra RJ, Beaule PE, Millis MB, Kim Y-J, sink EL, Schoenecker PL. Early Complications associated with the Periacetabular Osteotomy: A Prospective Multicenter Study.
  • Kim Y-L, Clohisy JC. Feasibility of Patients Willingness to Participate in a Randomized control Trial for the Surgical and Nonsurgical treatment of Femoroacetabular Impingement.

Research Promoted by IHDI

Pavlik Harness Consensus

The first phase of this project will achieve consensus for the standardized application of the Pavlik Harness as practiced by a group of experts. The second phase will aim to achieve consensus on the management of Developmental Hip Dysplasia using the Pavlik Harness based on its standard application.  This project is being coordinated by The Hospital for Sick Children and University of Toronto. Members of the IHDI Medical Advisory Board serve as the panel of experts. The Delphi Method used in these studies is a scientific method for consensus development and is used to identify the most widely accepted principles based on the experience and knowledge of recognized experts. The results will aim to provide guidelines for standardized application of the Pavlik Harness treatment. By obtaining consensus agreement as to the optimum management of hip dysplasia using the Pavlik Harness, we will then be able to compare this treatment to other treatment options to ultimately define best practice.


Systematic Review of Medial Open Reduction of the Hip for DDH

Systematic reviews are a statistically recognized method for identifying and reviewing all previous scientific publications on a single topic. Conducting this type of review may reveal information that becomes more apparent when a focused review is conducted rather than accumulating information over years of reading individual publications.

Medial open reduction of the hip is a less invasive type of surgery that may be used to put the hip back into the socket for infants who fail Pavlik harness and/or closed reduction and casting. After the hip is in the socket, a cast is used for several months similar to closed reduction until the hip becomes stable. Short term results have been good in patients younger than one year and sometimes a bit older. Long term results are less promising and several long-term studies have been reported over the years. This review has looked at long term results and specifically highlights concerns about AVN which is a known potential risk from the procedure. The paper, which has been authored by Members of the Medical Advisory Board of the IHDI has now been accepted for publication in the Bone and Joint Journal, one of the premier scientific journals in the field of orthopedic surgery.

3D Imaging in Closed Reduction for Developmentally Dislocated Hips

Closed reduction and spica casting is a standard procedure for putting a dislocated hip back into its socket in infants from 3 months to 18 months of age. One of the risks of this procedure is redislocation where the hip slides back out of the joint. Traditionally following surgery special scans such as CT or MRI are used to check that the hip is in the correct position. IHDI affiliated Surgeons at The Hospital for Sick Children at the University of Toronto are using 3D fluoroscopy as a new way of imaging the hip during the closed reduction procedure. They have authored a study that has shown that 3D Fluoroscopy is safe, has a very low dose of radiation and gives an excellent assessment of the position of the hip following closed reduction surgery. This type of imaging may become more widely used in the future to improve outcomes in surgery for hip dysplasia. This study has now been submitted for publication to one of the pediatric orthopedic journals.

Additional Articles

  • Chan A, Cundy PJ, Foster BK, Keane RJ, Byron-Scott R. (1999) Late diagnosis of congenital dislocation of the hip and presence of a screening program: South Australian population-based study. Lancet 354: 1514-1517.
  • Azzopardi T, Van Essen P, Cundy PJ, Tucker G, Chan A (2011). Late diagnosis of developmental dysplasia of the hip: an analysis of risk factors. J Pediatr Orthop B 20(1):1-7.
  • Williams N, Foster BK, Cundy PJ (2012). Is swaddling damaging our babies’ hips? Med J Aust 197(5):272.

Please contact us if you would like more information about any of the above studies, or can make a donation for these and future research projects for hip dysplasia.

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