Is patient-reported outcome after treatment of unstable pelvic ring injuries related to pelvic symmetry? A prospective study

Purpose To determine the relation between pelvic symmetry, as measured by the cross-measurement technique, and patient-reported outcome measures (PROMs) in terms of functional status and health-related quality of life. Methods In this prospective cohort study, X and Y measurements were taken according to the cross-measurement technique on AP radiographs of patients who were treated for an unstable pelvic ring injury in a level-1 trauma center. Patients completed PROMs at the time of admission (recalled pre-injury score) and one year following their injury, reporting their functional status with the Short Musculoskeletal Function Assessment (SMFA-NL), specifically the lower extremity dysfunction (LED), problems with daily activities (PDA) and mental and emotional problems (MEP) subscales, and quality of life with EuroQol-5D (EQ-5D). Subgroup analyses were also performed. PROMs were used to analyze the relation between pelvic symmetry and patient-reported outcome, using Spearman’s Rank correlation coefficients. Results A total of 130 patients (mean age 58 (SD18) years) with an unstable pelvic ring injury were included, of which 95 (73%) sustained type-B injuries and 35 (27%) type-C injuries. Sixty-three (49%) patients were treated operatively. The median pelvic symmetry ratio was 1.01 (IQR: 0.05). Weak or no correlations were found between the pelvic symmetry scores and the outcome measurements (Spearman’s correlation coefficients: LED r = 0.09; PDA r = 0.11; MEP r =-0.02; and EQ-5D r =-0.08). Subgroup analyses revealed no correlations. Conclusions No significant relation was found between pelvic symmetry, measured radiologically, and functional status and health-related quality of life, one year following an unstable pelvic ring injury.