Hip Impingement - Understanding Cartilage Damage

• Quantitative Computed Tomography (qCT) [ Time Frame: pre-op (within 6 weeks of surgery) ] [ Designated as safety issue: No ]
  qCT
• Quantitative Motion Analysis [ Time Frame: pre-op (within 6 weeks of surgery) ] [ Designated as safety issue: No ]
  Quantitative motion analysis recording and quantifying kinetic and kinematic data occuring at the hip joint. Data recorded during normal level walking and during completion of simulated daily tasks (uphill, downhill walking, stairs, squatting, sitting, rising from a chair).

Femoro-acetabular impingement (FAI) is a known cause of hip pain and possibly a major cause of adult hip osteoarthritis. The relationship between cam-type FAI deformity characteristics and joint degradation to better identify 'at-risk' patients requiring corrective surgery will be scrutinized to gain a better understanding of the condition's natural history. The influence of certain morphologies (e.g. size and location of the deformity) will be analyzed to determine if this leads to aberrant loading of regions of the cartilage and subchondral bone, resulting in cartilage damage and joint degradation. Additionally, this research will determine if changes in the subchondral bone precede cartilage degeneration.

The methodology for establishing the morphology/cartilage degeneration relationship includes Magnetic Resonance Image (MRI) analysis, three-dimensional motion analysis and computer simulation/finite element analysis.

The outcomes of this research may lead to a reduction in total hip replacement cases by as much as 70%, saving many Canadians from a painful and debilitating condition and reducing costs to the Canadian health care system by as much as $290 million annually.

• Controls
  Intervention: Procedure: MRI, qCT, motion analysis
• Asymptomatics
  Intervention: Procedure: MRI, qCT, motion analysis
• Symptomatics
  Intervention: Procedure: MRI, qCT, motion analysis

Inclusion Criteria:

• Group I: subjects with bilateral cam deformity and unilateral symptoms Hip pain longer than 6 months referred to the groin/lateral aspect of hip Positive impingement sign

Plain radiographs:

• absence of arthritis (Tonnis Grade 0 or 1)
• absence of dysplasia (center edge >25 degrees) on AP radiograph
• α-angle greater than 55 degrees on the Dunn view

Group II: asymptomatic subjects with cam deformity

• These patients will be recruited from our prevalence study (2006.813) with 200 asymptomatic individuals using MRI with radial sequences

Group III: asymptomatic control subjects with no deformity

• These patients will be recruited from our prevalence study (2006.813) which established their hip joint as having a normal femoral head neck contour. These subjects will be age-matched to Group I

Exclusion Criteria:

• Participants who do not meet the criteria above.