Table 4:

Preoperative versus Postoperative BMC/BMD comparisons

	Preoperative Mean/Median (SD/IQR)	Postoperative Mean/Median (SD/IQR)	Adjusted p-value
Bone Mineral Content (BMC) in grams
Total BMC	2358.32 (268.33)	2280.68 (271.15)	0.0021
Head BMC	530.70 (461.44, 597.83)	509.13 (459.70, 593.16)	1.002
Left Arm BMC	148.14 (139.98, 166.80)	146.61 (130.32, 158.66)	1.002
Right Arm BMC	153.25 (22.95)	159.89 (19.84)	1.001
Left Rib BMC	95.14 (29.04)	83.86 (18.19)	0.221
Right Rib BMC	104.14 (28.13)	88.57 (21.02)	0.011
Total Spine BMC	142.23 (27.51)	124.91 (22.13)	<0.0011
Lumbar Spine BMC	54.88 (48.32, 66.76)	56.41 (45.48, 67.45)	1.002
Pelvis BMC	249.34 (212.55, 267.57)	219.64 (186.68 – 251.07)	0.062
Left Leg BMC	434.34 (412.46, 456.27)	417.24 (401.06, 459.94)	1.002
Right Leg BMC	425.06 (402.63, 458.79)	425.89 (386.16, 457.81)	1.002
Bone Mineral Density (BMD) in grams/cm2
Total BMD*	1.13 (1.11, 1.19)	1.11 (1.08, 1.18)	0.092
Head BMD*	2.60 (2.33, 2.94)	2.43 (2.24, 2.76)	0.562
Left Arm BMD*	0.71 (0.67, 0.75)	0.71 (0.68, 0.74)	1.002
Right Arm BMD	0.73 (0.05)	0.73 (0.04)	1.001
Left Rib BMD	0.69 (0.11)	0.64 (0.10)	1.001
Right Rib BMD	0.69 (0.12)	0.64 (0.10)	0.021
Total Spine BMD	0.91 (0.12)	0.83 (0.10)	<0.0011
Lumbar Spine BMD	1.12 (0.99, 1.28)	1.07 (1.00, 1.19)	1.002
Pelvis BMD*	1.26 (1.21, 1.38)	1.21 (1.15, 1.29)	0.502
Left Leg BMD*	1.17 (1.13, 1.23)	1.15 (1.11, 1.20)	1.002
Right Leg BMD*	1.15 (1.12, 1.21)	1.15 (1.11, 1.21)	1.002
T-score*	0.20 (−0.43, 0.80)	0.00 (−0.75, 0.70)	0.062
Z-score*	0.55 (0.20, 1.30)	0.35 (−0.10, 1.05)	1.002

Data presented as median with interquartile range or mean with standard deviation as appropriate.

^{1 –}Paired T-Test ;

^{2 –}Wilcoxon Sign Rank Test;

^{* -}contains ties of zeros, resulting in approximate p-values