Table 1.
Demographics and Clinical Variables of Patients With Atypical Femoral Fracture (AFF) and Typical Subtrochanteric Femoral Fracture
| Atypical femoral fracture (n = 69) | Typical subtrochanteric femoral fracture (n = 393) | p Value | |
|---|---|---|---|
| n (%) | n (%) | ||
| Age (years), mean (SD) | 71.2 (8.7) | 73.8 (12.3) | 0.087 |
| BMI (kg/m2), mean (SD) | 23.5 (3.8) | 23.9 (5.9) | 0.754 |
| Female | 60 (87.0) | 295 (75.1) | 0.031 |
| Race | |||
| Chinese | 51 (83.6) | 266 (74.3) | 0.144 |
| Malay | 5 (8.2) | 66 (18.4) | |
| Indian/others | 5 (8.2) | 26 (7.3) | |
| eGFR mean (SD) | 76.5 (21.5) | 75.8 (35.1) | 0.870 |
| Creatinine median (IQR) | 73 (62, 88) | 77 (60, 100) | 0.262 |
| 25OHD (μg/L), mean (SD) (n = 353) | 28.6 (8.3) | 22.3 (11.5) | 0.061 |
| Charlson comorbidity score, mean (SD) | 3.2 (1.4) | 3.9 (2.0) | 0.002 |
| Smokers | 1 (1.5) | 14 (3.7) | 0.354 |
| Fragility fracture history | 15 (22.7) | 105 (27.3) | 0.433 |
| Rheumatoid arthritis | 5 (7.3) | 4 (1.0) | 0.001 |
| Type 2 diabetes mellitus (DM2) | 9 (13.0) | 153 (38.9) | <0.001 |
| HbA1c (%) in DM2, mean (SD) (n = 131) | 6.52 (0.51) | 7.25 (2.5) | 0.257 |
| TSH (mIU/L), median (IQR) (n = 277) | 1.19 (0.56, 3.95) | 1.50 (0.92, 2.50) | 0.439 |
| Prodromal symptoms | 7 (10.1) | 18 (4.6) | 0.060 |
| Bilateral fracture | 3 (4.4) | 10 (2.5) | 0.403 |
| Delayed healing | 2 (2.9) | 2 (2.3) | 0.760 |
| Surgical management | 65 (94.2) | 289 (73.9) | <0.001 |
| Repeat surgical procedure | 2 (2.9) | 8 (2.1) | 0.643 |
| Time to healing (months), median (IQR) | 2 (1, 3) | 3 (1, 3) | 0.480 |
| Antiresorptive drug use (either oral BP/zoledronic acid/denosumab) | 35 (50.7) | 44 (11.2) | <0.001 |
|
28 | 35 | |
|
5 | 6 | |
|
2 | 2 | |
|
0 | 1 | |
| Duration of BP use (months), median (IQR) | 56.5 (28, 66) | 15.5 (4, 36) | <0.001 |
| Glucocorticoid use | 5 (7.3) | 5 (1.3) | 0.002 |
SD = standard deviation; BMI = body mass index; eGFR = estimated glomerular filtration rate; IQR = interquartile range; 25‐OHD = 25‐hydroxyvitamin D; HbA1C = hemoglobin A1c; TSH = thyroid‐stimulating hormone; BP = bisphosphonate.