PURPOSE: To construct a questionnaire to assess outcomes in patients who underwent internal fixation for acetabular fractures.

METHODS: 27 female and 100 male consecutive patients (mean age, 50 years) who underwent internal fixation for acetabular fractures were included. Patients were asked to report their outcomes at months 6, 12, and 24 using a questionnaire. The initial questionnaire was constructed by an expert group. There were 11 closed questions, each came with 6 responses from ?no discomfort? to ?very severe discomfort?. Three open questions were added to cover topics that were not included. The content validity and relevance of the 11 closed questions was determined using factor analysis to determine the number of factors involved. Factorability of the correlation matrix was measured via the Bartlett test of sphericity and Kaiser-Meyer- Olkin (KMO) measure of sampling sufficiency. Factor loadings of <0.50 were considered acceptable for factor representation. Reliability in terms of internal consistency was expressed as Cronbach alpha coefficients. The responses to the 3 open questions were analysed and categorised by a single assessor.

RESULTS: 120 (94%) of the patients completed at least one questionnaire, and 92 (72%) completed all 3 questionnaires during the follow-up period. Based on responses to the 6-month questionnaire, responses to the 11 closed questions were significantly intercorrelated (Spearman 0.17-0.80). After factor analysis and analysis of responses to open questions, the number of questions was reduced to 6 and included questions related to pain, walking, hip motion, leg numbness, sexual life, and operation scar. Reliability of the questionnaire was estimated to alpha=0.89. Criterion validity was adequate with a high correlation with the Short Form 36 (r=0.56-0.80).

CONCLUSION: Patients treated with acetabular fractures can be adequately assessed using the 6-item questionnaire and one global question concerning impact on activities of daily living.