Low psoas major muscle area as a risk factor for contralateral hip fracture following intertrochanteric fracture.

Objective: This study aimed to investigate the relationship between the psoas major muscle area as a risk factor and subsequent contralateral hip fractures in patients with initial intertrochanteric fractures.

Methods: Of 136 treated for intertrochanteric fractures, 104 female patients had computed tomography done to assess their fractures at initial stage and had been followed up for more than 2 years. These patients were then divided into 2 groups: i.e. those who had a contralateral hip fracture (CF) (n=16) and those who did not (NF) (n=88) groups. We mainly assessed the relationship between the corrected psoas major muscle area (CPMA) at initial fracture and the occurrence of contralateral hip fracture.

Results: The CF group had significantly lower CPMA than the NF group (p=0.001). There was positive correlation between the CPMA and the period from the initial to the contralateral hip fracture in the CF group. The CPMA cutoff value of 480.98 mm2/m2, was showed sensitivity of 63.6% and specificity of 87.5% in receiver operating characteristic curve analysis for all patients.

Conclusions: The lower CPMA was associated with the contralateral hip fracture within 2 years from initial intertrochanteric fracture. The low CPMA would be a risk factor for contralateral hip fracture.