Stress-Based biomechanical modeling in hip dysplasia Surgery: A scoping review

Stress-based biomechanical modeling is increasingly used to evaluate joint mechanics and support surgical planning in developmental dysplasia of the hip (DDH). This scoping review examines how such models are applied in DDH surgery, the mechanical insights they provide, and their readiness for clinical translation. A systematic search of four databases identified 21 studies published between 2007 and 2024. Finite element analysis, discrete element analysis, and analytical approaches such as HIPSTRESS were used to simulate surgical correction and assess joint mechanics. Most models were applied in the preoperative phase to guide acetabular reorientation or quantify changes in load distribution. Across studies, surgical correction was consistently associated with reductions in peak contact-based metrics (approximately 30-50%) and increases in contact area. However, these improvements did not systematically correspond to normalization of the internal mechanical state of the joint, and several studies reported persistent abnormal loading despite apparently satisfactory radiographic outcomes. Reported stress magnitudes varied widely across modeling approaches despite relatively comparable loading conditions, suggesting that differences in geometry, subject-specificity, and constitutive assumptions play a dominant role. Most studies relied on literature-based loading conditions rather than subject-specific data, introducing a potential mismatch between applied forces and anatomical representation. All findings were derived from computational models, with limited verification, sparse validation, and minimal replication across independent cohorts or modeling frameworks. In addition, most models relied on simplified assumptions, including static loading conditions and linear elastic material behavior, and did not account for time-dependent or mechanobiological processes. Although stress-based biomechanical modeling shows promise for improving the mechanical understanding and optimization of DDH correction, its clinical translation remains limited. Future work should prioritize subject-specific loading conditions, improved model validation, and integration into clinically applicable workflows.