Accelerometer-Based Navigation versus Conventional Total Knee Arthroplasty for Posttraumatic Knee Osteoarthritis

Area of Science:

• Orthopedic surgery
• Biomedical engineering
• Radiographic analysis

Background:

• Posttraumatic osteoarthritis (PTOA) often presents with limb deformities complicating total knee arthroplasty (TKA).
• Accelerometer-based navigation (ABN) shows potential for restoring neutral mechanical axis (MA) in TKA, but data in PTOA patients are limited.
• Accurate limb alignment is crucial for TKA success, especially in cases with pre-existing deformities.

Purpose of the Study:

• To compare the lower limb mechanical axis (MA) accuracy between ABN-assisted TKA (ABN-TKA) and conventional TKA (cTKA) in patients with PTOA.
• To evaluate prosthesis alignment and functional outcomes following ABN-TKA versus cTKA in PTOA patients.

Main Methods:

• Retrospective analysis of 28 PTOA patients undergoing TKA: 16 in the cTKA group and 12 in the ABN-TKA group.
• Standing long-leg radiographs were used to assess MA and prosthesis alignment.
• MA outliers were defined as deviations beyond ± 3°; perioperative outcomes and 2-year Oxford Knee Score (OKS) were also analyzed.

Main Results:

• ABN-TKA group demonstrated significantly better MA accuracy (1.60° ± 2.09°) compared to the cTKA group (3.59° ± 1.34°, p=0.01).
• The incidence of MA outliers was significantly lower in the ABN-TKA group (25.0%) versus the cTKA group (78.6%, p=0.02).
• Prosthesis alignment and 2-year OKS were comparable between groups; complications included 2 periprosthetic infections (cTKA) and 1 fracture (iTKA).

Conclusions:

• Both conventional TKA and ABN-TKA effectively improved postoperative MA and functional outcomes in PTOA patients.
• ABN-TKA provided superior MA accuracy and reduced outlier rates compared to conventional TKA.
• ABN-TKA represents a valuable alternative for achieving precise limb alignment in TKA for PTOA.