Combined Anterior Pelvic (CAP) approach for fracture acetabulum fixation - Functional outcome evaluation and predictors of outcome

Objective Ilio-inguinal approach has been considered standard anterior approach for acetabulum fracture fixation. Different modifications of this approach have been described. This study analysed the patients treated using a Combined Anterior Pelvic (CAP) approach - minimal AIP (anterior intra-pelvic) with modified ilio-femoral along with ’anterior superior iliac spine’ osteotomy. This combined approach provides wide exposure of pelvis to direct visualise the entire anterior column from sacroiliac joint to pubic symphysis, medial side of quadrilateral plate and entire iliac wing with minimal retraction of soft tissues required. Methods Data of patients treated from July 2014 to June 2018 for acetabulum fracture using CAP approach was retrieved from hospital record system. Inclusion criteria were - acetabulum fractures treated surgically using CAP approach. Exclusion criteria were – age less than 18 years, associated pelvis ring injury and incomplete peri-operative radiological record (pre-operative/post-operative antero-posterior, 45° obturator and 45° iliac oblique radiographs and pre-operative computed tomographic (CT) scans. 62 patients who met inclusion exclusion criteria were called in out-patient-department for final functional evaluation using Matta modified Merle d’aubigne score. Results Out of 62 patients 47 patients who turned up for final functional evaluation were included in study. 19 patients had excellent, 15 had good, 2 had fair and 11 had poor results. Age less than 40 years, anterior column fracture pattern, Pre-operative fracture displacement >20 mm, fracture comminution and post-operative fracture reduction within 3 mm were the predictors of the functional outcome. When analysed using logistic regression model, post-operative fracture reduction was found to be the only significant predictor of functional outcome. Conclusion CAP approach is useful anterior approach to acetabulum. Fracture reduction is the independent predictor of functional outcome. Comparison of this approach with other anterior approaches to acetabulum can be area of further research.