Accuracy of portable navigation during THA in patients with severe developmental dysplasia of hip

Area of Science:

• Orthopedic Surgery
• Medical Imaging
• Biomedical Engineering

Background:

• Acetabular cup placement in total hip arthroplasty (THA) for developmental dysplasia of the hip (DDH) presents significant challenges.
• Accurate positioning is crucial for long-term implant survival and patient outcomes.

Purpose of the Study:

• To evaluate the orientation accuracy of acetabular cup insertion during THA using a portable navigation system in DDH patients.
• To compare accuracy between patients with severe DDH and those with non-DDH/mild DDH.

Main Methods:

• Retrospective cohort study of 64 patients undergoing THA with an infrared stereo camera-matching portable navigation system.
• Comparison of intraoperative navigation angles with postoperative CT-measured angles.
• Analysis of differences and predictive factors for outliers in acetabular cup placement.

Main Results:

• Average absolute abduction differences were 3.9° (severe DDH) and 3.3° (non-DDH/mild DDH).
• Average anteversion differences were 4.7° (severe DDH) and 2.3° (non-DDH/mild DDH), with a significant difference between groups.
• Severe DDH and posterior pelvic tilt were associated with larger navigation differences (>5° anteversion).

Conclusions:

• Portable navigation demonstrates acceptable accuracy for THA in DDH patients, even in severe cases.
• Close attention is warranted during navigation-assisted THA for severe DDH.
• The system's accuracy may be clinically acceptable considering its cost-effectiveness.