Coronal Malalignment Is Infrequently Present in Patients With Aseptic Tibial Loosening

Area of Science:

• Orthopedic Surgery
• Biomechanical Engineering
• Medical Imaging

Background:

• Coronal malalignment and poor implant positioning are potential risk factors for aseptic tibial loosening after total knee arthroplasty (TKA).
• Previous studies present conflicting evidence regarding the association between alignment and implant loosening.
• There is growing interest in kinematic alignment techniques for TKA.

Purpose of the Study:

• To investigate the incidence of coronal malalignment of the limb and tibial component in patients undergoing revision surgery for aseptic tibial loosening.
• To assess the relationship between coronal alignment parameters and aseptic tibial loosening in TKA.

Main Methods:

• A retrospective cohort study identified 73 patients revised for aseptic tibial loosening.
• Preoperative and postoperative radiographs from the primary TKA were analyzed to determine coronal limb and tibial component alignment.
• Adequate alignment was defined as neutral or valgus limb alignment and tibial implant position within 3° of the neutral mechanical axis.

Main Results:

• Only 5.5% of patients (4/73) exhibited tibial component varus alignment exceeding 3°.
• 94.5% of patients (69/73) had well-aligned tibial implants.
• The average limb coronal alignment was 3° valgus, with 8.2% (6/73) of patients showing coronal varus limb alignment.

Conclusions:

• Limb and tibial implant malalignment are infrequent in TKA revisions for aseptic tibial loosening.
• The majority of revised cases fall within established "safe" alignment parameters.
• Factors beyond coronal alignment likely play a more significant role in the etiology of aseptic tibial loosening.