Clinical efficacy between the patients with and without BMP₂.

Note: * P<0.05 The statistical value was derived from chi-square test (no statistical value can be obtained from the Fisher's exact test); P<0.05 between IIb and IIc as well as IIc and IIIa; statistical difference was also found between Type L1 and Type L3, and there were significant statistical differences between pre-and post-operation Harris score, but no statistical differences between IBG+BMP2 and IBG groups.