[Computer-assisted navigated cup placement in primary and secondary dysplastic hips]

Area of Science:

• Orthopedic Surgery
• Medical Imaging
• Biomedical Engineering

Background:

• Acetabular implant positioning critically affects total hip arthroplasty range of motion and dislocation risk.
• Computer-Assisted Surgery (CAS) systems offer 3D planning for precise implant placement.
• Reliability of CAS in dysplastic hip conditions requires further investigation.

Purpose of the Study:

• To evaluate the reliability of acetabular implant positioning using CAS in primary and secondary dysplastic hip cases.
• To compare the accuracy of CAS-guided implant placement in dysplastic versus non-dysplastic hips.

Main Methods:

• Prospective randomized study of 100 total hip replacements.
• Postoperative computed tomography (CT) used for cup position verification.
• Focused analysis on 18 primary and 2 secondary dysplastic cases.

Main Results:

• Similar anteversion angles achieved in dysplastic cases (21.5-22.4°) compared to normal hips (21.5°), with slightly larger standard deviation.
• Inclination angles in dysplastic cases (44.5° ± 5.47°) were comparable to normal cases (42.3° ± 4.31°).
• Successful cup implantation depth achieved in 15 out of 18 dysplastic cases.

Conclusions:

• CAS systems demonstrate utility and accuracy in positioning acetabular implants, even in dysplastic hip conditions.
• Three-dimensional preoperative CT-based planning is advantageous for achieving optimal cup positioning.
• CAS assists surgeons in achieving ideal, individualized cup positions that might otherwise be challenging.