Table 3 Comparisons of the four primary and five secondary findings on MRI and low- and high-grade instability on the Lachman and pivot shift tests
Parameter | Early MRI group (n = 89) | Late MRI group (n = 65) | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Lachman test | OR (95% CI) | Pivot shift test | OR (95% CI) | Lachman test | OR (95% CI) | Pivot shift test | OR (95% CI) | |||||
Low (n = 51) | High (n = 38) | Low (n = 16) | High (n = 73) | Low (n = 35) | High (n = 30) | Low (n = 9) | High (n = 56) | |||||
Primary findings | ||||||||||||
Nonvisualization | 4 | 8 | 3.1 (0.9–11.3) # | 1 | 11 | 2.7 (0.3–22.5) | 11 | 16 | 2.5 (0.9–6.9) † | 2 | 25 | 2.8 (0.5–14.8) |
Discontinuity | 36 | 25 | 1.5 (0.5–5.0) | 14 | 47 | 0.2 (0.03–1.9) | 21 | 11 | 0.5 (0.1–2.5) | 4 | 28 | 4.2 (0.7–24.8) |
Abnormal signal | 36 | 24 | 1.2 (0.4–3.8) | 13 | 47 | 0.5 (0.1–2.4) | 10 | 7 | 1.3 (0.4–4.8) | 3 | 14 | 1.0 (0.2–5.1) |
Abnormal shape | 33 | 24 | 1.7 (0.6–5.1) | 12 | 45 | 0.7 (0.2–2.6) | 10 | 6 | 1.0 (0.3–3.7) | 3 | 13 | 0.9 (0.2–4.5) |
Secondary findings | ||||||||||||
Deep sulcus sign | 22 | 15 | 0.9 (0.4–2.0) | 8 | 29 | 0.7 (0.2–2.0) | 9 | 4 | 0.4 (0.1–1.6) | 2 | 11 | 0.9 (0.2–4.7) |
Segond fracture | 2 | 1 | 0.7 (0.1–7.6) | 1 | 2 | 0.4 (0.04–5.0) | 1 | 0 | 1.0 (0.9–1.0) | 0 | 1 | 1.0 (1.0–1.1) |
PCL angle (<105°) | 12 | 10 | 1.2 (0.4–3.1) | 2 | 20 | 2.6 (0.6–12.7) | 19 | 22 | 2.3 (0.8–6.6) | 7 | 34 | 0.4 (0.1–2.3) |
Anterior translation (≥7 mm) | 31 | 23 | 1.0 (0.4–2.3) | 5 | 49 | 4.5 (1.4–14.4) * | 20 | 23 | 2.5 (0.8–7.3) ‡ | 4 | 39 | 2.9 (0.7–12.0) |
Bone contusion | ||||||||||||
Absent or medial compartment | 11 | 4 | 0.4 (0.1–1.5) | 2 | 13 | 1.5 (0.3–7.5) | 23 | 25 | 2.6 (0.8–8.6) | 7 | 41 | 0.8 (0.2–4.2) |
Lateral compartment | 18 | 17 | 1.5 (0.6–3.5) | 6 | 29 | 1.2 (0.4–3.4) | 8 | 5 | 0.7 (0.2–2.3) | 1 | 12 | 2.2 (0.3–19.2) |
Both compartments | 22 | 17 | 1.1 (0.5–2.5) | 8 | 31 | 0.7 (0.3–2.2) | 4 | 0 | 0.9 (0.8–1.0) | 1 | 3 | 0.5 (0.04–4.9) |