Influence of acetabular and femoral version on fractures of the femoral neck

Abstract

Background: Fractures through the proximal femur are broadly grouped into intertrochanteric fractures and intracapsular fractures. It is not clear why a patient may sustain an intertrochanteric fracture as compared with an intracapsular fracture. There is an established relationship between relative hip retroversion and the development of osteoarthritis. We postulate retroversion also may be a risk factor for having intracapsular fractures develop.

Questions/purposes: We looked specifically at the geometry of the hip to analyze the possibility of a relationship between acetabular version, femoral version, and Mckibbin's instability index and fracture type.

Patients and methods: We recruited 40 patients with fractures of the femoral neck for the study. There were 15 men and 25 women with a mean age of 80 years (range, 57-92 years). There were 14 intertrochanteric fractures and 26 intracapsular fractures. After treating their fracture, the contralateral hip was scanned in a CT scanner and assessed by two independent observers to establish the acetabular and femoral version.

Results: We found no correlation between proximal femoral fracture type and the contralateral femoral version, femoral neck length, acetabular version, or Mckibbin's instability index or between fracture type and age or gender.

Conclusions: There appears to be no correlation between proximal femoral fracture type and acetabular or femoral version.

Level of evidence: Level II, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

Fig. 1A–D

The box plots show (A) acetabular version, (B) femoral version, (C) Mckibbin’s instability index, and (D) femoral neck length in the patients with intracapsular (Ic) and intertrochanteric (It) fractures. No major differences in distribution of the acetabular and femoral version measurements are seen between the two groups. Patients 17 and 36 appear to be outliers in their respective groups. The edges of the rectangular boxes represent the upper and lower quartiles whereas the solid line corresponds to the median. The upper and lower tails reflect the 90th and 10th percentiles, respectively. See Table 3 for numerical values.