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. Author manuscript; available in PMC: 2019 May 1.
Published in final edited form as: J Orthop Res. 2018 Jan 16;36(5):1435–1443. doi: 10.1002/jor.23832

Table 2.

Physical and Biomechanical Features of Femurs Across Vitamin D Adjusted Chow Groups

Measurement Deficient Vitamin D (DD) (0 IU/g) Ca = 0.95%* Insufficient Vitamin D (ID) (2.25 IU/g) Ca = 0.95%* Sufficient Vitamin D Control (CD) (5 IU/g) Ca = 0.95%* Hyper-Vitamin D (HD) (40 IU/g) Ca = 0.94%* P-Value
Characteristics of rats
Intake Weight (g) (prior to dietary manipulation)** 271.00 ± 4.80 272.50 ± 4.17 270.00 ± 7.04 270.50 ± 7.69 NS
Pre-surgery Weight (g) 421.64 ± 83.27 446.42 ±34.54 424.15 ± 70.61 431.42±70.99 NS
Characteristics of femur
Femur Length (mm) 41.23 ± 1.85 41.71 ± 1.05 42.22 ± 1.47 41.43 ± 1.97 NS
Femur MicroCT
Cortical Thickness (mm) 0.90 ± 0.07 0.86 ± 0.06 0.87 ± 0.06 0.93 ± 0.10 NS (P=0.06)1
Moment of Inertia (mm4) 10.47 ± 1.66 10.14 ± 2.30 10.13 ± 1.94 12.05 ± 2.28 p<0.012
Cross Sectional Area (mm2) 9.45 ± 0.57 9.21 ± 0.95 9.34 ± 0.86 10.16 ± 1.07 p<0.013
Bone Volume/Total Volume (fBV/TV) 0.67 ± 0.03 0.66 ± 0.03 0.66 ± 0.03 0.67 ± 0.04 NS
Bone Volume (fBV) 34.26 ± 2.42 33.11 ± 3.39 33.59 ± 3.09 36.55 ± 3.81 P<0.014
Young’s Modulus (N/mm4) 7202±736.92 7198 ± 950.57 7367±1500.00 7152±1029.00 NS
Femur Biomechanics
Max Load (N) 205.27 ± 20.37 193.48 ± 29.58 200.88 ± 21.99 233.84 ± 31.61 p<0.015
Stiffness (N/mm) 445.91 ± 40.09 429.23 ± 74.91 433.75 ± 64.41 505.70 ± 58.50 p<0.016
Toughness (Nmm) 116.45 ± 27.57 109.69 ± 25.27 109.89 ± 22.38 127.11 ± 40.79 NS
Femur Bone Ashing
Dry Weight 0.92 ± 0.08 0.88 ± 0.08 0.93 ± 0.09 0.96 ± 0.02 NS
Ash Weight 0.59 ± 0.05 0.57 ± 0.06 0.60 ± 0.07 0.64 ± 0.08 NS(P=0.06)7
Ash Fraction (fAF) 0.64 ± 0.02 0.64 ± 0.01 0.64 ± 0.02 0.67 ± 0.01 p<0.0018
Ash Density (fAD, g/mL) 0.64 ± 0.05 0.67 ± 0.05 0.66 ± 0.07 0.74 ± 0.06 p=0.0019

Mean ± SD measurement values of left and right femurs. Values given as mean ± SD, NS = Not Significant

*

% Calcium by weight of rat chow diet

**

SAS-Mixed, Main effect of weight gain across time for all rats (P<0.001), no Vitamin D group effect (NS). SAS-GLM:

1

Femur Cortical Thickness: with vitamin dietary group(NS); [w/pre surgery serum vitamin D (model R2=0.25, P<0.01)]

2

Femur Moment of Inertia: R2 = 0.13 P<0.01, contrast HD > CD, ID, (p<0.05)

3

Femur Cross Sectional Area: R2 = 0.15 P<0.01, contrast HD > CD, ID, (p<0.05); HD>DD, P=0.06

4

Femur Bone Volume (fBV): R2 = 0.13 P<0.01, contrast HD > CD, ID, (p<0.05)

5

Femur Max Load: R2 = 0.27 P<0.01, contrast HD > CD, ID, (p<0.05)

6

Femur Stiffness: R2 = 0.22 P<0.01, contrast HD > CD, ID, (p<0.05)

7

Femur Ash Weight: R2 = 0.16 P<0.06, contrast HD > ID, (p<0.05)

8

Femur Ash Fraction: R2 = 0.32 P<0.001, contrast HD > CD, ID, DD (p<0.05)

9

Femur Ash Density: R2 = 0.31 P<0.001, contrast HD > CD, ID, DD (p<0.05)