Table 2 Main outcomes
|  | n | 1 week postoperative | n | 1 year postoperative | n | Change (1 week–1 year postoperative) |
|---|---|---|---|---|---|---|
BMD of Gruen zone 1 (g/cm2) | 427 | 0.801 (0.717, 0.891) | 427 | 0.768 (0.702, 0.842) | 427 | − 0.033 (− 0.116, 0.044) |
BMD of Gruen zone 7 (g/cm2) | 427 | 0.889 (0.716, 1.094) | 427 | 0.807 (0.729, 0.97) | 427 | − 0.057 (− 0.157, 0.072) |
BMD of total Gruen zones (g/cm2) | 427 | 1.44 (1.323, 1.519) | 427 | 1.395 (1.286, 1.482) | 427 | − 0.025 (− 0.09, 0.024) |