The Reliability of Intraoperative Hip Arthrography in Cerebral Palsy Hip Reconstruction Original Research
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Background: This study investigates surgeon interpretation of intraoperative hip arthrography after femoral osteotomy to guide decision-making regarding addition of concomitant pelvic osteotomy (PO) for Cerebral Palsy (CP) hip reconstruction.
Methods: Ten orthopaedic surgeons reviewed preoperative radiographic images of 21 children with CP, undergoing hip reconstruction. Surgeons recorded if PO was indicated after 1) reviewing the preoperative radiographs. Raters who exhibited poor reliability (kappas <0.60) were excluded from arthrogram analysis. Agreement in decision-making was evaluated by estimating the concordance across six raters with respect to changing their recommendation after reviewing the arthrogram images by estimating Fleiss’s kappa coefficient.
Results: Intra-rater reliability for the three surgeons who conducted repeat evaluations was substantial to almost perfect (k=0.67, 0.86, 1.00). Pairwise inter-rater reliability for radiographic decision was moderate to almost perfect with kappa values ranging from 0.56 to 0.87. In 20 of 32 hip evaluations at least 5 of 6 raters recommended PO after reviewing the radiograph, 64% of cohort (122/192). However, upon reviewing the arthrogram images, only 45% (86/192) of reviews recommended a PO. Attending surgeons changed their decisions away from PO in 35% of cases overall; while fellows changed their decisions in only 7% of cases. Further radiographic characterization of the labrum position demonstrated substantial agreement (kappa=0.73; 95% CI=0.48-0.98) and almost perfect agreement regarding presence of dye pool (kappa=0.85; 95% CI=0.50-1.00).
Conclusions: Interpretation of intraoperative hip arthrography to guide addition of PO in CP hip reconstruction is reliable with moderate agreement according to experience level and with substantial retest reliability.