Table 2.

The specific conditions of extension loss and flexion loss in each study.

Study	Measuring method	BPTB: extension loss	HT: extension loss	BTBP: flexion loss	HT: flexion loss
Ibrahim[37]	Physical examination	≥10°:2 (5%),≤5°:12 (30%)	≤5°:8 (17.7%)	≥15°:5 (12.5%)	≥15°: 1 (3%)
Gifstad[35]	Physical examination	≥5°:2 (5%)	≥5°:3 (8%)	≥5°:4 (10%)	≥5°:6 (17%)
Ahlden[23]	Unknown	3 (14%)	3 (12%)	6 (27%)	12 (48%)
Barenius[24]	Unknown	3–5°:26 (39%)	3–5°:8 (13%)	6–15°:13 (19%)	6–15°:16 (27%)
Matsumoto[34]	Unknown	5°:3 (8.1%),10°:1 (2.7%)	5°:2 (5.7%)	10°:2 (5.4%)	10°:1 (2.8%)
Konrads[27]	Unknown	5°:1 (4.2%)	Normal	Normal	Normal
Mohtadi[29]	Long-arm goniometer	>3°:0 (0%)	>3°:0 (0%)	Passive flexion: 142.5°±7.3°	Passive flexion: 142.2°±7.8°
Zaffagnini3[41]	Physical examination	≤2°:21 (84%),3–5°:3 (12%),6–10°:0 (0%),>10°:2 (8%)	≤ 2°:18 (72%),3–5°:5 (20%),6–10°:1 (4%),>10°:1 (4%)	≤5°:16 (64%),6–15°:6 (24%), 16–25°: 2 (8%),>25°:1 (4%)	≤5°:22 (88%),6–15°:2 (8%),16–25°:1 (4%),>25°:0 (0%)
Sajovic[28]	Unknown	2 (8.3%)	1 (4.2%)	0 (0%)	0 (0%)