Conference Coverage

Imageless Navigation Adds No Benefit to CT-Based 3D Planning for THA

Edited by:
Brian McCurdy

Key Highlights

  • CT-based 3D planning alone and planning with imageless navigation produced similar hip reconstruction accuracy.
  • In both groups, 80%–90% of hips met predefined radiographic thresholds for cup and stem orientation.
  • Oxford Hip Score and EQ-5D-5L improvements were substantial and comparable at 12 months.

Adding intraoperative imageless navigation to computed tomography (CT)–based 3-dimensional planning did not significantly improve reconstruction accuracy or early functional outcomes in a randomized trial of primary total hip arthroplasty (THA). Both groups demonstrated comparable component positioning and patient-reported improvement at 12 months. The study was presented at the 2026 American Association of Hip and Knee Surgeons (AAHKS) Annual Meeting in Dallas.

The investigators examined whether navigation provides additional value when surgeons already use CT-based 3D planning. Their single-center, 3-surgeon trial enrolled 106 patients undergoing primary uncemented THA for osteoarthritis. Patients were assigned to 3D planning alone (n=56) or planning augmented with imageless navigation (n=50). Demographic characteristics were comparable, most procedures used an anterior approach, and no intraoperative fluoroscopy was used.

All patients had standardized low-dose CT before and after surgery. Investigators superimposed planned and delivered reconstructions in 3 dimensions to assess center-of-rotation restoration and component orientation. The primary outcome was absolute deviation between planned and delivered reconstruction. Secondary outcomes included the proportion meeting predefined accuracy thresholds and changes in Oxford Hip Score (OHS) and EQ-5D-5L at 12 months.

Study Findings

Center-of-rotation restoration and component orientations were similar between groups. Reported acetabular inclination differences were 0.3° ± 6.8° with planning alone versus −0.4° ± 6.4° with navigation (P = .644). Corresponding acetabular anteversion differences were 3.3° ± 9.6° versus 4.9° ± 7.7° (P = .418), and femoral version differences were −0.5° ± 8.0° versus 1.3° ± 7.2° (P = .488). Combined anteversion was also comparable, at 39.3° ± 13.0° versus 43.5° ± 12.8° (P = .126). Between 80% and 90% of hips in each group met radiographic accuracy thresholds.

At 12 months, OHS improvement was 25 ± 9 points with planning alone and 25 ± 10 points with navigation (P = .8). EQ-5D-5L improvement was 0.28 ± 0.17 versus 0.29 ± 0.17, respectively (P = .9). Two periprosthetic joint infections required debridement, antibiotics, and implant retention, and 1 fracture required revision.

Clinical Implications

According to the authors, imageless navigation provided no additional benefit for routine primary THA performed with CT-based 3D planning. They attributed value to the visual cues and templated sizing accuracy provided by planning and suggested that additional effects might be possible with image-guided navigation or robotics.

Expert Commentary

“In routine primary THA performed with 3D-CT-based planning, imageless navigation did not provide added benefits in improving hip reconstruction accuracy or early functional outcomes,” the researchers concluded.

Reference

Koh CK, Bakke D, Grammatopoulos G, Schneider MT, Feibel RJ, Garceau S. Does imageless navigation add value beyond CT-based 3D planning in primary THA? An RCT. Paper #34. Abstract presented at the American Association of Hip and Knee Surgeons Annual Meeting, November 5–8, 2026, Dallas, TX.