Association Between Cam-Type Deformities and Magnetic Resonance Imaging–Detected Structural Hip Damage

University of Bern and Inselspital, Bern University Hospital, Bern, Switzerland.
Arthritis & Rheumatology (Impact Factor: 7.76). 12/2011; 63(12):4023-30. DOI: 10.1002/art.30589
Source: PubMed


Femoroacetabular impingement may be a risk factor for hip osteoarthritis in men. An underlying hip deformity of the cam type is common in asymptomatic men with nondysplastic hips. This study was undertaken to examine whether hip deformities of the cam type are associated with signs of hip abnormality, including labral lesions and articular cartilage damage, detectable on magnetic resonance imaging (MRI).
In this cross-sectional, population-based study in asymptomatic young men, 1,080 subjects underwent clinical examination and completed a self-report questionnaire. Of these subjects, 244 asymptomatic men with a mean age of 19.9 years underwent MRI. All MRIs were read for cam-type deformities, labral lesions, cartilage thickness, and impingement pits. The relationship between cam-type deformities and signs of joint damage were examined using logistic regression models adjusted for age and body mass index. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were determined.
Sixty-seven definite cam-type deformities were detected. These deformities were associated with labral lesions (adjusted OR 2.77 [95% CI 1.31, 5.87]), impingement pits (adjusted OR 2.9 [95% CI 1.43, 5.93]), and labral deformities (adjusted OR 2.45 [95% CI 1.06, 5.66]). The adjusted mean difference in combined anterosuperior femoral and acetabular cartilage thickness was -0.19 mm (95% CI -0.41, 0.02) lower in those with cam-type deformities compared to those without.
Our findings indicate that the presence of a cam-type deformity is associated with MRI-detected hip damage in asymptomatic young men.

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Available from: Christian W A Pfirrmann, Sep 30, 2014
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    • "A 20-year longitudinal study of an asymptomatic population-based cohort has shown that the presence of a cam lesion increases the risk of future THR by sixfold.16 Cam lesions have been observed in > 50% of patients undergoing hip replacement,17 and significant cartilage damage has also been seen intra-operatively at the specific sites where impingement occurs.18 Lastly, early signs of cartilage damage have been detected using delayed Gadolinium Enhanced Magnetic Resonance Imaging of Cartilage (dGEMRIC) in asymptomatic patients with cam lesions.19 "
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    ABSTRACT: The number of surgical procedures performed each year to treat femoroacetabular impingement (FAI) continues to rise. Although there is evidence that surgery can improve symptoms in the short-term, there is no evidence that it slows the development of osteoarthritis (OA). We performed a feasibility study to determine whether patient and surgeon opinion was permissive for a Randomised Controlled Trial (RCT) comparing operative with non-operative treatment for FAI. Surgeon opinion was obtained using validated questionnaires at a Specialist Hip Meeting (n = 61, 30 of whom stated that they routinely performed FAI surgery) and patient opinion was obtained from clinical patients with a new diagnosis of FAI (n = 31). Clinical equipoise was demonstrated when surgeons were given clinical scenarios and asked whether they would manage a patient operatively or non-operatively. A total of 23 surgeons (77%) who routinely perform FAI surgery were willing to recruit patients into a RCT, and 28 patients (90%) were willing to participate. 75% of responding surgeons believed it was appropriate to randomise patients to non-operative treatment for ≥ 12 months. Conversely, only eight patients (26%) felt this was acceptable, although 29 (94%) were willing to continue non-operative treatment for six months. More patients were concerned about their risk of developing OA than their current symptoms, although most patients felt that the two were of equal importance. We conclude that a RCT comparing operative and non-operative management of FAI is feasible and should be considered a research priority. An important finding for orthopaedic surgical trials is that patients without life-threatening pathology appear willing to trial a treatment for six months without improvement in their symptoms.
    02/2013; 2(2):33-40. DOI:10.1302/2046-3758.22.2000137
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    ABSTRACT: Objective: To determine the association between cam impingement, which is hip incongruity by a non-spherical femoral head and development of osteoarthritis. Methods: A nationwide prospective cohort study of 1002 early symptomatic osteoarthritis patients (CHECK), of which standardised anteroposterior pelvic radiographs were obtained at baseline and at 2 and 5 years follow-up. Asphericity of the femoral head was measured by the α angle. Clinically, decreased internal hip rotation (≤20°) is suggestive of cam impingement. The strength of association between those parameters at baseline and development of incident osteoarthritis (K&L grade 2) or end-stage osteoarthritis (K&L grades 3, 4, or total hip replacement) within 5 years was expressed in OR using generalised estimating equations. Results: At baseline, 76% of the included hips had no radiographic signs of osteoarthritis and 24% doubtful osteoarthritis. Within 5 years, 2.76% developed end-stage osteoarthritis. A moderate (α angle>60°) and severe (α angle>83°) cam-type deformity resulted in adjusted OR of 3.67 (95% CI 1.68 to 8.01) and 9.66 (95% CI 4.72 to 19.78), respectively, for end-stage osteoarthritis. The combination of severe cam-type deformity and decreased internal rotation at baseline resulted in an even more pronounced adjusted OR, and in a positive predictive value of 52.6% for end-stage osteoarthritis. For incident osteoarthritis, only a moderate cam-type deformity was predictive OR=2.42 (95% CI 1.15 to 5.06). Conclusions: Individuals with both severe cam-type deformity and reduced internal rotation are strongly predisposed to fast progression to end-stage osteoarthritis. As cam impingement might be a modifiable risk factor, early recognition of this condition is important.
    Annals of the rheumatic diseases 06/2012; 72(6). DOI:10.1136/annrheumdis-2012-201643 · 10.38 Impact Factor
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    ABSTRACT: Objective To compare the results of hip arthroscopy in patients under the age of 25 with those over 25 years. Design From March 2006 until May 2010, data were collected on all patients who underwent hip arthroscopy for symptomatic intra-articular hip pathology. The patients were divided into two groups based on age (less than 25 years and over 25 years). Patients completed the modified Harris hip score (MHHS), non-arthritic hip score (NAHS) and hip dysfunction and osteoarthritis outcome score (HOOS) questionnaires at baseline then at 6 weeks, 6 months, 12 months and at latest follow-up. Participants 88 patients who underwent 94 hip arthroscopies by the senior author. Mean age was 24.3 (range 11–57 years). Results The mean NAHS and HOOS subscales for pain and activities of daily living were worse at baseline in over 25 groups. Follow-up ranged from 9 to 68 months. 45 hips had greater than 3 year follow-up. The MHHS improved in both groups with a mean difference in the under-25 group of 16.22, and 20.88 in the over 25s. Improvements in the NAHS and HOOS subscales were also of a similar magnitude. There was no statistically significant difference between outcome scores of the two groups at the latest follow-up visit. Conclusions We found a comparable improvement in outcome between those patients under 25 years and those over 25 years. We propose that hip arthroscopy is of potential benefit to patients with symptoms of femoroacetabular impingement regardless of age.
    British Journal of Sports Medicine 07/2012; 47(4). DOI:10.1136/bjsports-2012-091028 · 5.03 Impact Factor
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