Multiple studies analyzed the proximal femoral morphology using different specimens and methods of measuring [
10,
11]. We decided to analyze conventional radiographies since they are used as a standard in pre-operative planning for total hip arthroplasty. Proximal femoral anatomy became very important, because reconstruction of the native individual values was recognized as a prerequisite factor for the success in total hip arthroplasty [
12]. Hip anatomy is a subject to a high individual variability [
13]. Gender is one of the parameters associated with anatomical hip variability [
14]. In our group of patients, we observed statistically significant differences between genders in FHD and LFO parameters, while FNA and FNSA were of similar values in both genders. Many studies observed differences in femoral geometry between races and ethnic group [
5,
6]. We compared values from this study with values from similar studies which described proximal femoral anatomy of different races and ethnic groups, but we also compared our results with the results of authors who analyzed Caucasian proximal femoral geometry [
15‐
19]. We detected differences in proximal femoral geometry between Croatian population and other ethnic groups. The comparison of the mean values of proximal femoral geometry between Croatian population and various ethnic groups is shown in Table
3. Comparing our results of proximal femoral geometry with the Asian population from Korea [
20] and China [
21], we observed that Croatian population has significantly smaller FNSA and FNA but higher LFO. Comparing the results of the Croatian population with the results of Indian studies, proximal femoral geometry has shown similarities in FNSA with the results of Rawal et al. [
6] but smaller values in comparison with the study of Minakshi et al. [
22]. The results for FHD are smaller and for LFO higher in our study compared with both of these studies. FNA is higher in the Croatian population in comparison with the findings by Rawal et al. [
6]. Comparing our results with results from varius studies of the Caucasian population, we also detected some differences in proximal femoral geometry. The FHD in our study was 38.84 ± 5.32 mm, while the median value of the femoral head diameter in the study of Rubin et al. [
16] was 43.4 ± 2.6 mm. Unnanuntana et al. [
19] analyzed proximal femoral morphology in American Caucasians, and the diameter of the femoral head in his study was 52.09 ± 4.4 mm, significantly larger than in the Croatian population. With regard to FNSA, varying ranges have been described as reference ranges. Boese et al. reported the value ranging from 98 to 160° in the healthy population [
13]. Normal range of the FNSA is generally considered between 120 and 140° [
23] with a global mean of 126.4° [
24]. Values < 120° are classified as coxa vara and > 140° as coxa valga [
25]. FNSA together with femoral neck length directly affects the LFO. The reconstruction of LFO largely depends on femoral stem design. Offset reduction of more than 15% or more than 5 mm in comparison with native value reduces the abductor moment arm influencing the gate pattern [
26]. The FNSA in our study was 125.34 ± 4.26°, and this is significantly lower in comparison with that of the Turkish [
15] 129.71 ± 4.4
°, French 129.2 ± 7.8
° [
17], and Norwegian population [
18] 127.7 ± 7.6
° but higher than in the Swiss population [
16] 122.9 ± 7.6. The mean value for LFO in the Croatian population is 51.22 ± 8.44 mm. This was the highest value in comparison with the values reported in all analyzed studies regardless of race or ethnicity, and the difference was statistically significant. Another parameter of proximal femoral anatomy that should be reconstructed during hip arthroplasty is FNA. Error in adjusting the version of the femoral component of endoprosthesis will modify the lever arms, foot position, and the gait pattern and is recognized as a risk factor for hip dislocation [
27] and can decrease periprosthetic bone density [
28]. The literature revealed a discrepancy between native femoral neck anteversion and version of the femoral component of endoprosthesis, ranging in excessive anteversion to retroversion, especially in cementless prostheses [
29]. In most studies, the degree of version of the femoral component was significantly increased compared to the degree of native femoral neck anteversion [
30]. Previous studies have shown that femoral anteversion of Asians is generally larger than that of Caucasians where the mean value is about 10° [
12]. FNA in the Croatian population is 16.53 ± 1.97°, between Asian and Caucasian values.
Table 3
Comparative analysis of the proximal femoral geometric parameters reported in different studies; the results significantly statistically different (P < 0.05) from the results obtained from present study for Croatian population are asterisk marked
Femoral head diameter/mm | 38.84 ± 5.32 | 45.41 ± 3.7* P < 0.001 | 52.09 ± 4.4 P < 0.001 | 47.13 ± 3.4* P < 0.001 | 43.4 ± 2.6* P < 0.001 | – | – | 45.50 ± 3.4* P < 0.001 | – | 42.32 ± 4.1* P < 0.001 |
Femoral neck length/mm | 44.29 ± 4.31 | 48.4 ± 5.6* P < 0.001 | – | 34.56 ± 4.7* P < 0.001 | 47 ± 7.2* P = 0.01 | – | – | – | 45.40 ± 3.2 | 44.75 ± 8 |
Neck shaft angle/° | 125.34 ± 4.26 | 124.42 ± 5.5 | 132.69 ± 5.9* P < 0.001 | 129.71 ± 4.4* P < 0.001 | 122.9 ± 7.6* P = 0.024 | 129.2 ± 7.8* P < 0.001 | 127,7 ± 7,6* P = 0.017 | 130.27 ± 5.4* P < 0.001 | 129.88 ± 5.7* P < 0.001 | 128.90 ± 4.5* P < 0.001 |
Angle of femoral neck anteversion/° | 16.53 ± 1.97 | 10.9 ± 4.2* P < 0.001 | – | – | – | – | 10.4 ± 6.7* P < 0.001 | – | 21.58 ± 3.3* P < 0.001 | – |
Lateral femoral offset/mm | 51.22 ± 8.44 | 40.23 ± 4.8* P < 0.001 | 41.16 ± 6.0* P < 0.001 | 41.11 ± 5.3* P < 0.001 | – | 40.5 ± 7.5* P < 0.001 | – | 37.88 ± 5.4* P < 0.001 | – | 42.92 ± 5.5 * P < 0.001 |