Title : Acetabular bone density CT- Evaluation- Implications to THR
Abstract:
Statement of the Problem: Implantation of the acetabular component into poor-quality bone during total hip replacement (THR) is considered to be a major risk factor for its instability. High incidence of developmental dysplasia of the hip (DDH) and occult endocrine-related bone tissue pathology as well as invalidity of routine DXA for assessment of acetabular bone density justify the necessity of precise preoperative bone quality evaluation directly in the presumed implantation site.
Methodology & Theoretical Orientation: There were revealed a complex comparative CT-mophometric assessment of acetabular spongious bone X-ray density (attenuation coefficient-based) due to proposed approach of 32 normal hips and 65 hips with developmental dysplasia Crowe I-III types. Patients with DXA-verified osteoporosis or osteopenia were noted and moved to separate research group. The evaluation implied 5 mminterval measuring due to topographical zones (supraacetabular area, anterior and posterior acetabular walls). Obtained results were stratified due to dysplastic sectoral deficiency subtype: antero-lateral, postero-lateral or total deficiency and analyzed with appropriate statistical methods. Mann-Whitney test, one-way analysis of variance and Spearman's rank correlation were used respectively.
Findings: All dysplastic hips showed increasing of X-ray density of supraacetabular area with simultaneously with X-ray density loss of anterior and posterior acetabular walls in all sectoral deficiency subtypes. There were determined progressive increase of the X-ray density of the supraacetabular bone and steady decrease of anterior and walls ones in correlation with the femoral head cranial displacement. The most severe loss of acetabular spongious bone X-ray density in all the zones was observed during the total sectoral deficiency subtype.
Conclusion & Significance: Detected changes of acetabular spongious bone X-ray density reflects the local degenerative processes and following changes of the biomechanical bone tissue properties occurred due to dysplastic deficiency formation that influence primary and delayed acetabular component's stability. The defined normal ranges and regularities of acetabular spongious bone X-ray density changes during DDH that should be taken into consideration for preoperative planning of acetabular component implantation.
