APPENDIX 2. Data extraction of included studies

Determinant / Author / Specification of the determinant / Outcome / MD with matching 95%CI or OR with matching 95% CI
STATIC MEASURES
Foot and ankle characteristics
Longitudinal arch angle (LAA) (°)
Relaxed stance / Barton et al, 2010 / LAA / Cases: mean 143.6°(7.8sd)
Controls: mean 150.4°(7.1sd)
Effect size (95% CI) 0.90 (0.23,1.53)
p value: 0.019 / MD:-6.80
95% CI:-11.57,-2.03
Foot posture index (FPI) (°)
Relaxed stance / Barton et al, 2010 / FPI / Cases: mean: 2.7(3.2sd)
Controls: mean:0.3(3.7sd)
Effect size (95% CI) 0.71 (0.005,1.33)
P value: 0.015 / MD:2.40
95% CI:0.19,4.61
Normalized Vertical Navicular Heigth (NVNH) (%foot length)
Relaxed stance / Barton et al, 2010 / NVNH / Cases: mean 16.4(3.3sd)
Controls: mean 18.4(2.7sd)
Effect size (95% CI): 0.64 (-0.01.126)
P value: 0.076 / MD:-2.00
95% CI:-3.93,-0.07
Calcaneal angle (CA)
Relaxed stance / Barton et al, 2010 / CA / Cases: mean 5.3°(3.6sd)
Controls: mean 3.5 °(4.1sd)
Effect size (95% CI) 0.46 (-0.18,1.08)
P value: 0.150 / MD:1.80
95% CI:-0.,67,4.27
Normalized dorsal arch height (NDAH) (% foot length)
Relaxed stance / Barton et al, 2010 / NDAH / Cases: mean 24.6%(2.2sd)
Controls: mean: 25.6 %(2.1sd)
Effect size (95% CI) 0.44 (-0.20,1.05)
P Value: 0.240 / MD:-1.00
95% CI:-2.38,0.38
Normalized navicular drop (NNDrop) (% foot length)
Foot posture relative, Subtalar joint neutral / Barton et al, 2010 / NNDrop / Cases: mean: 2.9 %(1.4sd)
Controls: mean: 1.3 %(1.8sd)
Effect size (95% CI) 1.02 (0.34,1.65)
P value: 0.003 / MD:1.60
95% CI:0.57,2.63
Normalized dorsal arch height (NDAH) difference (% foot length)
Foot posture relative, Subtalar joint neutral / Barton et al, 2010 / NDAH difference / Cases: mean 1.4%(0.7sd)
Controls: mean 0.7%(0.7sd)
Effect Size (95% CI) 1.02 (0.34, 1.65)
P Value: 0.005 / MD:0.70
95% CI:0.25,1.15
Normalized navicular drift (% foot length) (NNDrift)
Foot posture relative, Subtalar joint neutral / Barton et al, 2010 / NNDrift / Cases: mean:3.0% (1.4sd)
Controls: mean: 1.4%(2.0sd)
Effect Size: 0.92 (0.25,1.55)
P value: 0.005 / MD:1.60
95% CI:0.49,2.71
LAA Difference (°)
Foot posture relative, Subtalar joint neutral / Barton et al, 2010 / LAA difference / Cases: mean: 5.8°(3.3sd)
Controls: mean: 2.8°(3.4sd)
Effect size (95% CI) 0.90(0.23,1.53)
P value: 0.007 / MD:3.00
95% CI:0.86,5.14
CA Difference (°)
Foot posture relative, Subtalar joint neutral / Barton et al, 2010 / CA difference / Cases: mean 4.8°(3.1sd)
Controls: mean 2.2° (3.6sd)
Effect size (95% CI) 0.75 (0.10,1.38)
P value: 0.006 / MD:2.60
95% CI:0.45,4.75
Rearfoot angle measurement Right(°) / Livingston et al, 2003 / Right rearfoot angle / Cases: mean: females: 7.55 (5.50sd)
Controls: mean: females: 10.5 (4.8sd)
Cases: mean: males: 9.7 (4.65sd)
Controls: mean: males: 9.6 (4.2sd)
ns / MD females: -2.95 95%CI -6.27,0.37
MD males:0.10 95%CI -3.29, 3.49
Rearfoot angle measurement Left (°) / Livingston et al, 2003 / Left rearfoot angle / Cases: mean: females: 8.35 (5.15sd)
Controls: mean: females: 9.8 (4.3sd)
Cases: mean: males: 11.2 (5.7sd)
Controls: mean: males: 10.1 (5.5sd)
ns / MD females:-1.45 95%CI -4.49, 1.59
MD males: 1.10 95%CI -3.27, 5.47
Right Rearfoot – Left Rearfoot / Livingston et al, 2003 / Difference / Cases: mean: females: -0.8 (7.0sd)
Controls: mean: females: 0.7 (5.4sd)
Cases: mean: males: -1.55 (6.15sd)
Controls: mean: males:-0.5 (5.6sd) / MD females:0.10 95%CI -3.87, 4.07
MD males:-1.05 95%CI -5.57, 3.47
Arch Height Index / Dierks et al, 201008 / Arch Height index / Cases: mean: 0.328(0.027)
Controls: mean: 0.317(0.024sd)
Ns
Both studies / MD:0.01
95% CI:-0.01,0.03
Arch index / Duffey et al, 2000 / Arch index / Cases: mean: 0.238(0.058 sem)=2.37sd
Controls: mean: 0.251(0.041 sem)=2.10sd
P value: 0.050 / MD:-0.01
95% CI:-0.71,0.68
Arch index / Thomee et al, 1995 / Arch index / Cases: mean: 14.7 (6.5sd)
Controls: mean: 14.8 (7.1sd)
NS / MD:-0.10
95% CI:-3.77,3.57
Pes cavus (number and %) / Haim et al, 2006 / Pes cavus / Cases: 10 (16%)
Controls: 4 (16%)
P value: 1.00 / OR: 1.03
95% CI 0.29, 3.65
Pes planus (number and %) / Haim et al, 2006 / Pes planus / Cases: 19 (31%)
Controls: 4 (16%)
P value: 0.15 / OR: 2.38
95% CI 0.72, 7.88
Leg length
Absolute leg length difference (cm) / Duffey et al, 2000 / Absolute leg length difference / Cases: mean: 0.6(0.1 sem)=0.99sd
Controls: mean: 0.5(0.1 sem)=0.84sd
ns / MD:0.10
95% CI:-0.19,0.39
Relative leg length difference (cm) / Duffey et al, 2000 / Relative leg length difference / Cases: mean: 0.5(0.0 sem)=0.0sd
Controls: mean: 0.5(0.0 sem)=0.0sd
ns / MD:0.00
95% CI:0.00,0.00
½-1cm shorter dominant leg length difference (number and %) / Al-Rawi et al, 1997 / Shorter leg length in dominant leg / Cases: 33 (28.7%)
Controls: 26 (23.6%) / OR: 1.30
95% CI 0.72, 2.34
½-1cm longer dominant leg length difference (number and %) / Al-Rawi et al, 1997 / Longer leg length in dominant leg / Cases: 11 (9.1%)
Controls: 10 (9.6%) / OR: 1.09
95% CI 0.44, 2.68
No leg length differences between dominant leg and non-dominant (number and %) / Al-Rawi etl, 1997 / Equal leg length / Cases:71 (67.3%)
Controls: 74 (61.7%) / OR: 0.57
95% CI 0.32, 1.02
Q-angle in weight baring position
Q-angle(°) / Caylor et al, 1993 / Q-angle / Cases: mean 12.4°(5.1sd) range: ( 2° to 24°) unilateral
Controls: mean 11.1°(5.5sd) range:(-6° tot 24°) bilateral=> only 26 people used to calculate the MD
P value: 0.07 / MD:1.30
95% CI:-1.22,3.82
Q-angle (°) / Duffey et al, 2000 / Q-angle / Cases mean: 12.5° (0.5 sem)=4.97sd
Controls: mean: 11.2° (0.5 sem)=4.18sd
Ns / MD:1.30
95% CI:-0.14,2.74
Q-angle(°) / Emami et al, 2007 / Q-angle / Cases: mean 18.0°(adjusted sd:5.5)
Control: mean 14.4° (adjusted sd:4.6)
P<0.001 / MD:3.60
95% CI:2.19,5.01(adjusted)
Q-angle(°) / Patil et al, 2010 IN PRESS / Q-angle / Cases: mean: 11.5° (3.1sd)
Controls: mean: 11.0° (3.0sd) / MD:0.50
95% CI:-1.55,2.55
Q-angle(°) / Patil et al, 2010 / Q-angle / Cases: mean: 11.2°(adjusted sd: 3.6)
Controls: mean: 11°(adjusted sd: 3.5)
P value: 0.72 / MD:0.20
95% CI:-1.52,1.92(adjusted)
Q-angle (°) / Aglietti et al, 1983 / Q-angle / Cases mean: 20 (3.0sd)
Controls mean: 15 (3.0sd) / MD 5.00
95% CI 4.05, 5.95
Q-angle (°) / Haim et al, 2006 / Q-angle / Cases mean: 16.8 (7.0sd)
Controls mean: 12.5 (3.2sd)
P value: <0.001 / MD 4.30
95% CI 1.39, 7.21
Q-angle > 20° (number and %) / Haim et al, 2006 / Q-angle / Cases: 32( 52%)
Controls: 0 (0%)
P value: <0.001
Q-angle at 0° knee angle(°) / Thomee et al, 1995 / Q-angle / Cases: mean: 16.8° (4.6sd)
Controls: mean: 15.1° (4.9sd)
NS / MD:1.70
95% CI:-0.88,4.28
Q-angle at 30° knee angle(°) / Thomee et al, 1995 / Q-angle / Cases: mean: 11.9° (4.9sd)
Controls: mean: 13.5° (4.8sd)
NS / MD:-1.60
95% CI:-4.27,1.07
Quadriceps angle (°) / Willson et al, 2008 / Quadriceps angle / Cases: mean: 18.4° (3.8sd)
Controls: mean: 18.3° (4.2sd)
NS
AJSM / MD:0.10
95% CI:-2.46,2.66
Malalignment
Genu varum (number and %) / Haim et al, 2006 / Genu varum / Cases: 20 (33%)
Controls: 4 (16%)
P value: 0.12 / OR: 2.56
95% CI 0.77, 8.46
Genu valgum (number and %) / Haim et al, 2006 / Genu valgum / Cases: 36 (59%)
Controls: 11 (44%) / OR: 1.58
95% CI 0.62,4.00
Patella
Patellar tilt (°) / Powers et al, 2000 / Patellar tilt / Cases: 10.7°
Controls: 5.5°
P value 0.02
part II / MD: 5.2
Positive Patellar Tilt test (number and %) / Haim et al, 2006 / Patellar tilt test / Cases: 26 (43%)
Controls: 2 (8%)
P value: 0.002 / OR: 9.65
95% CI 2.08, 44.8
Patellar tilt angle (°) / Salsich et al, 2007 / Patellar tilt angle / Cases: mean: 12.4° (7.7sd)
Controls: mean: 9.0° (6.1sd) / MD:3.40
95% CI:-0.93,7.73
Patellar tilt angle (°) during full knee extension / Draper et al, 2009 / Patellar tilt angle / Cases: mean: 10
Controls: 4
P value: 0.01
Sulcus angle(°) / Eckhoff et al, 1994 / Sulcus angle / NS
Sulcus angle (°) / Laprade et al, 2003 / Sulcus angle / Cases mean: 139.6° (sd9.1)
Controls mean: 141.3° (sd6.2)
P value: 0.30 / MD:-1.70
95% CI:-5.53,2.13
Sulcus angle (°) / Powers et al, 2000 / Sulcus angle / Cases: 149.4°
Controls: 144.6°
Ns / MD: 4.8
Sulcus angle (°) / Haim et al, 2006 / Sulcus angle / Cases mean: 139 (5.1sd)
Controls mean: 138 (5.8sd)
P value: 0.43 / MD 1,00
95% CI -1.51, 3,51
Sulcus angle (°) / Aglietti et al, 1983 / Sulcus angle / Cases mean: 139 (4sd)
Controls mean: 137 (6sd) / MD 2,00
95% CI 0.25, 3.75
Patellar angle (°) / Laprade et al, 2003 / Patellar angle / Cases mean: 124.8° (sd6.8)
Controls mean: 125.5° (sd5.6)
P value: 0.06 / MD:-0.70
95% CI:-3.76,2.36
Lateral patellar angle unloaded (°) / Laprade et al, 2003 / Lateral patellar angle unloaded / Cases mean: 12.5° (sd 6.6)
Controls mean:10.6° (sd4.4)
P value:0.13 / MD:1.90
95% CI:-0.86,4.66
Lateral patellar angle loaded(°) / Laprade et al, 2003 / Lateral patellar angle loaded / Cases mean: 13.1° (sd7.5)
Controls mean: 11.2° (sd4.2)
P value: 0.20 / MD:1.90
95% CI:-1.09,4.89
Lateral patellofemoral angle(°) / Eckhoff et al, 1994 / Lateral patellofemoral angle / NS
Congruence angle (°) / Eckhoff et al, 1994 / Congruence angle / NS
Congruence angle unloaded (°) / Laprade et al, 2003 / Congruence angle unloaded / Cases mean: -21.2° (sd11.1)
Controls mean: -19.6° (sd7.4)
P value: 0.49 / MD:-1.60
95% CI:-6.24,3.04
Congruence angle loaded (°) / Laprade et al, 2003 / Congruence angle loaded / Cases mean:-18.1° (sd18.3)
Controls mean: -23.7° (sd9.8)
P value: 0.16 / MD:5.60
95% CI:-1.62,12.82
Congruence angle (°) (Merchant) / Haim et al, 2006 / Congruence angle / Cases mean: -4.2 (9.9sd)
Controls mean: -5.4(14sd)
P value: 0.70 / MD 1.20
95% CI -4.10, 6.50
Congruence angle (°) (Merchant) / Aglietti et al, 1983 / Congruence angle / Cases mean: -2.0 (9sd)
Controls mean: -8.0 (6sd) / MD 6.00
95% CI 3.83, 8.17
Laurin angle (°) with knees 20° flexed / Haim et al, 2006 / Laurin angle / Cases mean: 9.9(4.1sd)
Controls mean: 10.8(5.6sd)
P value: 0.47 / MD -0.90
95% CI -3.06,1.26
Laurin angle ≤0 ° (number and %) / Haim et al, 2006 / Laurin angle / Cases: 3 (5%)
Controls: 0 (0%)
P value: 0.55
Caton’s ratio / Laprade et al, 2003 / Caton’s ratio less 0.6 is an indication of patellar infera weheras a ratio greater than 1.3 is an indication of patellar alta. / Cases mean:1.00 (sd0.18)
Controls mean:1.03 (sd0.19)
P value: 0.59 / MD:-0.03
95% CI:-0.12,0.06
Pulsatile blood flow in the patella / Näslund et al, 2007 / Pulsatile blood flow in the patella difference in 20° and 90° flexed knees / Cases mean: relative position: -0.32 [95% CI, -0.48 to -/0.17]
Controls mean: relative position: 0.17 [95% CI, -0.05 to 0.31]
Median change in patients: -26%
Controls: median change: 0
P value <0.0002
Articular cartilage lesions / Joensen et al, 2001 / articular cartilage lesions / Cases: 17
Controls: 4 / OR:7.9
95% CI 1.9, 33
Bisect offset (% total patellar width) / Powers et al, 2000* / Bisect offset / Cases: 57.9%
Controls: 53.8%
ns
Contact area of total patellofemoral joint (mm2) / Salsisch et al, 2007 / Contact area / Cases: mean: 191.6mm2 (38.3sd)
Controls: mean: 220.3mm2 (44.5sd) / MD:-28.70
95% CI:-54.59,-2.81
Biscet offset index (patellar width) / Salsich et al, 2007 / Patellar displacement / Cases: mean: 0.69 (0.12sd)
Controls: mean: 0.62 (0.07sd) / MD:0.07
95% CI:0.01,0.13
Differences in Bisect offset between knee flexion angles 0° and 50° (%) / Draper et al, 2009 / Bisect offset / Cases: 10% larger than controls
P value: 0.03
Bisect offset in full knee extension / Draper et al, 2009 / Bisect offset / Cases: (16 out of 23) 70%
Controls: (7 out of 13) 54%
Differences:16%
P value: 0.01 / OR: 1.96
95% CI 0.48, 8.00
Patellar width (mm) / Salsich et al, 2007 / Patellar width / Cases: mean: 39.4° (2.7sd)
Controls: mean: 42.3° (3.5sd) / MD:-2.90
95% CI:-4.85,-0.95
Patellar height ratio Insall-Salvati method / Aglietti et al, 1983 / Patellar height / Cases mean: 1.08 (0.09sd)
Controls mean: 1.04 (0.11sd) / MD 0.04
95% CI 0.01, 0.07
Patellar height ratio Blackburne / Aglietti et al, 1983 / Patellar height / Cases mean: 0.91 (0.11sd)
Controls mean: 0.95 (0.13sd) / MD -0.04
95% CI -0.08, 0.00
Patellar glide as percentage of patellar width (%) / Haim et al, 2006 / Pateller glide / Cases: mean 30 (15sd)
Controls: mean 38 (11sd)
P value: 0.018 / MD -8.00
95% CI -14.6, -1.40
Patellar subluxation (number and %) / Haim et al, 2006 / Patellar subluxation / Cases: 15 (25%)
Controls: 1 (4%)
P value: 0.032 / OR: 7.83; 0.97,62.9
Surface area (mm2) / Tuncyurek et al, 2010 / Patellar surface area / Cases: mean:1393.6mm2 (300.7sd)
Controls: 1287.5mm2 (293.1sd)
NS / MD:106.10
95% CI:-133.74,345.94
Longitudinal length of the patellar tendon(mm) / Tuncyurek et al, 2010 / Length of patellar tendon / Cases: mean:53.2mm (7.5sd)
Controls: mean: 52.9mm (8.3sd)
NS / MD:0.30
95% CI:-5.90,6.50
Thickness of the middle part of the patellar tendon(mm) / Tuncyurek et al, 2010 / Thickness of the middle part of patellar tendon / Cases: mean: 4.53mm (0.90sd)
Controls: mean: 4.58mm(0.99sd)
NS / MD:-0.05
95% CI:-0.79,0.69
Lateral trochlear inclination (LTI) / Keser et al, 2008 / LTI / AKP group: mean 17.3° (6.5 SD),
Control group: mean 21.5°(5.7 SD)
P value <0.05 / MD:-4.20
95% CI:-6.04,-2.36
Trochlear dysplasia (n) / Keser et al, 2008 / Trochlear dysplasia / AKP groups: 18 (16.5%)