title: Patient-specific chondrolabral contact mechanics in patients with acetabular dysplasia following treatment with peri-acetabular osteotomy.
abstract: Using a validated, patient-specific finite element (FE) modeling protocol, we evaluated cartilage and labrum (i.e., chondrolabral) mechanics before and after peri-acetabular osteotomy (PAO) to provide insight into the ability of this procedure to improve mechanics in dysplastic hips.
  
  
  
  Five patients with acetabular dysplasia were recruited in this case-controlled, prospective study. Models, which included anatomy for bone, cartilage, and labrum, were generated from computed tomography (CT) arthrography scans acquired before and after PAO. Cartilage and labrum contact stress and contact area were quantified overall and regionally. Load supported by the labrum, expressed as a percentage of the total hip force, was analyzed.
  
  
  
  Percent cartilage contact area increased post-operatively overall, medially, and superiorly. Peak acetabular contact stress decreased overall, laterally, anteriorly, and superiorly. Average contact stress decreased overall, laterally, anteriorly, and posteriorly. Only average contact stress on the superior labrum and peak labrum stress overall decreased. Load supported by the labrum did not change significantly.
  
  
  
  PAO was efficacious at medializing cartilage contact and reducing cartilage contact stresses, and therefore may minimize deleterious loading to focal cartilage lesions, subchondral cysts, and cartilage delaminations often observed in the lateral acetabulum of dysplastic hips. However, the excessively prominent, hypertrophied labrum of dysplastic hips remains in contact with the femoral head, which continues to load the labrum following PAO. The clinical ramifications of continued labral loading following PAO are not known. However, it is plausible that failure to reduce the load experienced by the labrum could result in end-stage hip OA following PAO.
authors.affiliation: Department of Orthopaedics, University of Utah, 590 Wakara Way, Salt Lake City, UT 84108, USA; Department of Bioengineering, University of Utah, James LeVoy Sorenson Molecular Biotechnology Building, 36 S. Wasatch Drive, Rm. 3100, Salt Lake City, UT 84112, USA. Electronic address: christine.l.abraham@gmail.com.
authors.forename: C L
authors.initials: CL
authors.lastname: Abraham
authors.affiliation: Department of Orthopaedics, University of Utah, 590 Wakara Way, Salt Lake City, UT 84108, USA. Electronic address: knight.spencer@hotmail.com.
authors.forename: S J
authors.initials: SJ
authors.lastname: Knight
authors.affiliation: Department of Orthopaedics, University of Utah, 590 Wakara Way, Salt Lake City, UT 84108, USA; Department of Bioengineering, University of Utah, James LeVoy Sorenson Molecular Biotechnology Building, 36 S. Wasatch Drive, Rm. 3100, Salt Lake City, UT 84112, USA. Electronic address: chris.peters@hsc.utah.edu.
authors.forename: C L
authors.initials: CL
authors.lastname: Peters
authors.affiliation: Department of Orthopaedics, University of Utah, 590 Wakara Way, Salt Lake City, UT 84108, USA; Department of Bioengineering, University of Utah, James LeVoy Sorenson Molecular Biotechnology Building, 36 S. Wasatch Drive, Rm. 3100, Salt Lake City, UT 84112, USA; Scientific Computing and Imaging Institute, 72 S Central Campus Drive, Room 3750, Salt Lake City, UT 84112, USA. Electronic address: jeff.weiss@utah.edu.
authors.forename: J A
authors.initials: JA
authors.lastname: Weiss
authors.affiliation: Department of Orthopaedics, University of Utah, 590 Wakara Way, Salt Lake City, UT 84108, USA; Department of Bioengineering, University of Utah, James LeVoy Sorenson Molecular Biotechnology Building, 36 S. Wasatch Drive, Rm. 3100, Salt Lake City, UT 84112, USA; Scientific Computing and Imaging Institute, 72 S Central Campus Drive, Room 3750, Salt Lake City, UT 84112, USA; Department of Physical Therapy, University of Utah, 520 Wakara Way, Suite 240, Salt Lake City, UT 84108, USA. Electronic address: andrew.anderson@hsc.utah.edu.
authors.forename: A E
authors.initials: AE
authors.lastname: Anderson
mesh_terms: D000077:Acetabulum / Q000000981:diagnostic imaging / Q000503:physiopathology; D000328:Adult; D001696:Biomechanical Phenomena; D002358:Cartilage, Articular / Q000469:parasitology*; D016022:Case-Control Studies; D005260:Female; D020342:Finite Element Analysis; D006617:Hip Dislocation / Q000000981:diagnostic imaging* / Q000601:surgery*; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D010027:Osteotomy / Q000379:methods*; D011446:Prospective Studies; D012016:Reference Values; D018570:Risk Assessment; D013314:Stress, Mechanical; D014057:Tomography, X-Ray Computed / Q000379:methods; D016896:Treatment Outcome; D055815:Young Adult
keywords: Acetabular dysplasia; Cartilage; Finite element modeling; Hip; Labrum; Peri-acetabular osteotomy