Contemplate iliosacral screw in patients with developmental dysplasia of the hip

Our aim in the study was evaluating sacroiliac morphology in patients with DDH and its possible effect on appropriate iliosacral screw fixation.

Retrospective cohort study.

Level of evidence 3.

We evaluated the anteroposterior pelvis X-ray and pelvic CT scans of patients. We mainly divided the patients into two groups: DDH group (n:105) and control group (n:105).

The presence of the five qualitative characteristics of sacral dysplasia evaluated according to Route in both groups. The DDH group was divided into four subgroups according to the degree of hip dysplasia.

The cross-sectional area, length of the osseous corridor, coronal and vertical angulation evaluated in both groups.

The DDH group also exhibited a significantly higher S1 coronal and axial angulation, lower S1 cross-sectional area and S1 iliosacral screw length than the control group (p:0.033, p:0,002, p:0.006, p:0,019, respectively). According to the Rout classification, 9% were normal, 31% transient, 58% dysplastic in the DDH group. 45.7% were normal, 38% transient, 17% dysplastic in the control groups. These differences between the groups were statistically significant (p < 0.001). When the DDH groups were evaluated within themselves; no statistically significant difference was observed in S1 and S2 cross-sectional area, S1 and S2 maximum estimated iliosacral screw length, S1 and S2 axial and coronal angles assessment.

Sacral dysplasia was more common, narrower and more angled osseous canal for the iliosacral screw was found in the DDH group. There was no relation between the degree of hip dysplasia and sacrum morphology in the DDH group. Thus, we suggest the surgeons be aware of iatrogenic injury even in constrained dysplastic hips.