Results of two survey rounds showing the level of agreement with primary cam morphology definition, terminology, taxonomy and imaging outcomes statements
| Statments | Round 1 | Round 2 | ICC* | ICC 95% CI | ||||
| Not important/disagree | Critical/agree | Not important/disagree | Critical/agree | Lower bound | Upper bound | |||
| No | Definitions | |||||||
| 1 | Primary cam morphology develops during skeletal maturation as a normal physiological response to load | 3.3% | 80.3% | 1.6% | 85.9% | 0.69 | 0.53 | 0.80 |
| 2 | Primary cam morphology is not caused by previous disease, injury or an acute event; it represents a normal physiological response of the maturing skeleton to load | 3.3% | 72.1% | 1.6% | 81.3% | 0.79 | 0.68 | 0.87 |
| 3 | Secondary cam morphology develops due to existing hip disease or acute trauma, including Perthes disease, slipped capital femoral epiphysis, healed proximal femoral fractures or acute fracture | 0% | 73.8% | 1.6% | 81.0% | 0.54 | 0.34 | 0.70 |
| 4 | Primary cam morphology develops in young and active individuals, including athletes, likely due to load (eg, sporting activity) during prepubertal and pubertal skeletal maturation (load during growth) and its (physiological) effect on the proximal femoral growth plate | 0% | 87.1% | 0% | 96.9% | 0.69 | 0.53 | 0.80 |
| 5 | Primary cam morphology is common in young and active males, including athletes, likely due to sporting activity during prepubertal and pubertal skeletal maturation (load during growth) and its (physiological) effect on the proximal femoral growth plate | 4.9% | 73.8% | 0% | 79.4% | 0.80 | 0.68 | 0.88 |
| 6 | Primary cam morphology includes cam morphology of unknown origin | 8.8% | 49.1% | 9.5% | 52.4% | 0.52 | 0.30 | 0.69 |
| 7 | Cam morphology that develops in young and active individuals without any symptoms (eg, hip-related pain, stiffness) or history of previous/existing hip disease, is primary cam morphology until proven otherwise | 3.4% | 55.9% | 4.7% | 53.1% | 0.83 | 0.73 | 0.90 |
| 8 | Cam morphology is a cartilage or bony prominence (bump) of varying size at any location around the femoral head-neck junction, which changes the shape of the femoral head from spherical to aspherical | 1.6% | 90.5% | 1.5% | 92.3% | 0.47 | 0.26 | 0.64 |
| 9 | Primary cam morphology often occurs in male athletes in both hips | 5.1% | 50.8% | 3.2% | 45.2% | 0.89 | 0.83 | 0.94 |
| 10 | The most common outcome measure for cam morphology is a cartilage or bone alpha angle as a dichotomised or continuous variable on radiographs, CT scans or MRI, reported per hip, per person or both | 0% | 72.6% | 0% | 74.6% | 0.72 | 0.58 | 0.82 |
| 11 | Primary cam morphology likely develops during maturation in young adolescents (with no current or previous hip disease), possibly due to high-load sporting activity and other unconfirmed risk factors | 1.6% | 82.3% | 0% | 93.8% | 0.60 | 0.41 | 0.74 |
| 12 | A comprehensive definition for primary cam morphology would be: Primary cam morphology is a cartilage or bony prominence (bump) of varying size at any location around the femoral head-neck junction, which changes the shape of the femoral head from spherical to aspherical. It often occurs in male athletes in both hips. The most common outcome measure is a cartilage or bone alpha angle as a dichotomised or continuous variable on radiographs, CT scans or MRI, reported per hip, per person or both. Primary cam morphology likely develops during maturation in young adolescents (with no current or previous hip disease), possibly due to high-load sporting activity and other unconfirmed risk factors. | 0% | 93.7% | 1.6% | 96.9% | 0.44 | 0.21 | 0.62 |
| Terminology | ||||||||
| 13 | Cam morphology is the preferred term to use for a bone/ cartilage bump at any location around the femoral head-neck junction | 1.6% | 87.5% | 1.5% | 87.7% | 0.56 | 0.36 | 0.71 |
| 14 | Cam lesion is the preferred term to use for a bone/ cartilage bump at any location around the femoral head-neck junction | 75.8% | 6.5% | 83.1% | 4.6% | 0.84 | 0.69 | 0.91 |
| 15 | Cam deformity is the preferred term to use for a bone/cartilage bump at any location around the femoral head-neck junction | 71.0% | 12.9% | 81.5% | 7.7% | 0.67 | 0.50 | 0.79 |
| 16 | Cam abnormality is the preferred term to use for a bone/cartilage bump at any location around the femoral head-neck junction | 80.6% | 4.8% | 86.2% | 4.6% | 0.70 | 0.54 | 0.81 |
| 17 | Cam-type deformity is the preferred term to use for a bone/cartilage bump at any location around the femoral head-neck junction | 79.0% | 3.2% | 84.6% | 4.6% | 0.8 | 0.69 | 0.87 |
| 18 | Cam-type abnormality is the preferred term to use for a bone/ cartilage bump at any location around the femoral head-neck junction | 79.0% | 6.5% | 87.7% | 3.1% | 0.64 | 0.45 | 0.77 |
| 19 | Cam-type lesion is the preferred term to use for a bone/cartilage bump at any location around the femoral head-neck junction | 77.4% | 3.2% | 89.2% | 1.5% | 0.69 | 0.48 | 0.82 |
| 20 | Pistol grip deformity is the preferred term to use for a bone/cartilage bump at any location around the femoral head-neck junction | 85.2% | 1.6% | 92.2% | 0.0% | 0.64 | 0.40 | 0.78 |
| 21 | Pistol grip lesion is the preferred term to use for a bone/cartilage bump at any location around the femoral head-neck junction | 85.2% | 3.3% | 92.2% | 1.6% | 0.59 | 0.37 | 0.74 |
| 22 | Pistol grip abnormality is the preferred term to use for a bone/ cartilage bump at any location around the femoral head-neck junction | 85.2% | 4.9% | 92.2% | 1.6% | 0.44 | 0.22 | 0.63 |
| 23 | Cam-type impingement is the preferred term to use for hip-related pain due to a bony bump at any location around the femoral head-neck junction | 56.5% | 16.1% | 56.3% | 10.9% | 0.78 | 0.65 | 0.86 |
| 24 | Cam femoroacetabular impingement (FAI) is the preferred term to use for hip-related pain due to a bony bump at any location around the femoral head-neck junction | 53.2% | 27.4% | 51.6% | 20.3% | 0.83 | 0.74 | 0.90 |
| 25 | Cam-type FAI is the preferred term to use for hip-related pain due to a bony bump at any location around the femoral head-neck junction | 59.7% | 19.4% | 51.6% | 20.3% | 0.82 | 0.72 | 0.89 |
| 26 | FAI Syndrome with cam morphology is the preferred term to use for hip-related pain due to a bony bump at any location around the femoral head-neck junction | 7.9% | 69.8% | 7.8% | 75.0% | 0.65 | 0.47 | 0.77 |
| 27 | FAI Syndrome with cam deformity is the preferred term to use for hip-related pain due to a bony bump at any location around the femoral head-neck junction | 71.0% | 6.5% | 81.5% | 4.6% | 0.81 | 0.66 | 0.89 |
| 28 | FAI Syndrome with cam abnormality is the preferred term to use for hip-related pain due to a bony bump at any location around the femoral head-neck junction | 74.2% | 4.8% | 81.5% | 4.6% | 0.82 | 0.70 | 0.89 |
| 29 | FAI Syndrome with cam lesion is the preferred term to use for hip-related pain due to a bony bump at any location around the femoral head-neck junction | 71.0% | 4.8% | 83.1% | 4.6% | 0.72 | 0.52 | 0.84 |
| 30 | FAI Syndrome with cam-type abnormality is the preferred term to use for hip-related pain due to a bony bump at any location around the femoral head-neck junction | 74.2% | 6.5% | 84.6% | 1.5% | 0.72 | 0.55 | .83 |
| 31 | FAI Syndrome with cam-type deformity is the preferred term to use for hip-related pain due to a bony bump at any location around the femoral head-neck junction | 69.4% | 9.7% | 81.5% | 4.6% | 0.75 | 0.56 | 0.85 |
| Taxonomy | ||||||||
| 32 | We should distinguish between primary and secondary cam morphology in clinical practice | 6.5% | 74.2% | 6.2% | 83.1% | 0.87 | 0.79 | 0.92 |
| 33 | We should distinguish between primary and secondary cam morphology in research | 4.6% | 90.8% | 4.6% | 92.3% | 0.71 | 0.57 | .815 |
| 34 | We should distinguish between primary and secondary cam morphology in patients with FAI syndrome | 6.5% | 66.1% | 4.7% | 68.8% | 0.82 | 0.72 | 0.89 |
| 35 | We should distinguish between primary and secondary cam morphology in research participants with FAI syndrome | 4.7% | 84.4% | 4.6% | 90.8% | 0.69 | 0.53 | 0.80 |
| Imaging outcomes | ||||||||
| 36 | The main imaging modality for research on how primary cam morphology develops should be MR with radial imaging (1.5T or 3 T) | 1.9% | 75.9% | 1.8% | 89.3% | 0.81 | 0.59 | 0.90 |
| 37 | The minimum acceptable number of radial sequence MRI slices for research on how primary cam morphology develops should be 12 slices (30° intervals in all 12 clock face positions from 12 o'clock to 11 o'clock positions) | 0% | 60.0% | 0% | 81.6% | 0.7 | 0.49 | 0.83 |
| 38 | Referring to precisely quantifying the asphericity of the femoral head-neck junction on radial sequence MRI: use either radial sequences along the axis of the femoral neck (providing higher resolution images) or radial reconstructions from 3-dimensional acquisitions | 0% | 75.0% | 0% | 87.0% | 0.84 | 0.70 | 0.92 |
| 39 | The MRI protocol for research on how primary cam morphology develops should include: (1) unilateral small field-of-view sequences and radial images of a randomly selected or both hips; as well as (2) femoral torsion assessment (fast axial sequences of the distal knee—femoral condyles—and proximal femoral neck); and (3) a fluid sensitive sequence covering the whole pelvis (in axial or coronal planes; to screen for soft-tissue and bone marrow oedema beyond the hip) | 5.9% | 64.7% | 0% | 78.4% | 0.71 | 0.47 | 0.85 |
| 40 | The MRI for prospective research on how primary cam morphology develops should be repeated every 18 to 24 months | 11.3% | 56.6% | 7.3% | 56.4% | 0.86 | 0.78 | 0.92 |
| 41 | In primary cam morphology epidemiological research (eg, when regression is being used in aetiology or prognosis research) continuous imaging outcome measures (variables) like the alpha angle should be kept continuous | 3.6% | 72.7% | 0% | 89.3% | 0.77 | 0.58 | 0.87 |
| 42 | The cam morphology MRI outcome measure for research on how primary cam morphology develops (aetiology) should be the alpha angle for bone and cartilage as a continuous variable reported for all the o’clock locations around the femoral head-neck junction regardless of the symptomatic state of the research participant. | 5.4% | 66.1% | 0% | 80.7% | 0.81 | 0.68 | 0.89 |
| 43 | For research on how primary cam morphology develops it is important to quantify the epiphysial morphology MRI outcome measure using epiphysial extension | 4.8% | 57.1% | 0% | 65.9% | 0.83 | 0.68 | 0.91 |
| 44 | For research on how primary cam morphology develops the epiphysial morphology MRI outcome measure should also be quantified using epiphysial tilt | 5.1% | 43.6% | 0% | 44.2% | 0.81 | 0.67 | 0.90 |
| 45 | The main imaging modality for longitudinal primary cam morphology prognosis research should be anteroposterior (AP) pelvis and Dunn 45° view radiographs repeated at least every 5 years | 20.4% | 44.9% | 15.4% | 42.3% | 0.91 | 0.84 | 0.95 |
| 46 | The radiographic imaging outcome measure for research on primary cam morphology prognosis should be the alpha angle as a continuous variable reported for AP pelvis and Dunn 45° view radiographs | 15.7% | 56.9% | 11.3% | 67.9% | 0.90 | 0.83 | 0.94 |
| 47 | In addition to reporting alpha angles as continuous in studies on aetiology or prognosis the following quantitative and qualitative imaging outcome measures to categorise cam morphology can be useful in research or clinical practice: (1) Alpha angle ≥60° (preferred) (2) Head-neck offset <8 mm and head-neck offset ratio ≤0.15 usually at the anterior (3 o’clock) location around the femoral head-neck junction (in addition to (1)); Osseous or cartilage convexity of the femoral head neck junction at any location (in addition to (1) and (2)) | 2.1% | 52.1% | 0% | 72.5% | 0.81 | 0.68 | 0.89 |
Green (high agreement on ‘consensus in’): Statement scored as critical (7–9) by ≥70% of panel members and not important (1–3) by <15% of panel members.
Red (high agreement on ‘consensus out’): Scored as not important (1–3) by ≥70% of panel members and critical (7–9) by <15% of panel members.
Yellow (non-consensus): Neither of the ‘consensus in’ or ‘consensus out’ criteria were met.
ICC is an indication of the level of agreement (within-subject variation and between-subject variance of individual statement scores between round 1 and round 2.) We used the lower bound 95% CI of the ICC estimate as the basis to evaluate the level of reliability using the following general guideline: values <0.5 were classified as poor reliability ICC values 0.5–0.75 moderate reliability and 0.75–0.9 indicated good reliability and ICC values >0.9 indicated excellent reliability.
*Type A ICC coefficients using an absolute agreement definition; two-way mixed effects model where people effects are random and measures effects are fixed.
ICC, intraclass correlation coefficient.