Osteoporosis affects component positioning in computer navigation-assisted total knee arthroplasty.

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Radiology

Background:

• Computer-assisted navigation in total knee arthroplasty (TKA) offers benefits but is susceptible to tracker pin movement.
• Undetected pin movement can compromise lower limb alignment and component accuracy.
• Osteoporosis is a potential risk factor for tracker pin movement during TKA.

Purpose of the Study:

• To compare radiographic outcomes in osteoporotic versus non-osteoporotic knees undergoing navigation-assisted TKA.
• To investigate the influence of osteoporosis on tibial component position and lower limb alignment.

Main Methods:

• Prospective case-control study comparing 44 osteoporotic knees with 56 non-osteoporotic knees.
• Osteoporosis defined by T-score ≤ -2.5 in the femoral neck or lumbar spine.
• Radiographic assessment of tibial component position at 6-month follow-up.

Main Results:

• Osteoporotic knees showed a significantly greater valgus coronal tibial component position compared to non-osteoporotic knees (p=0.041).
• Osteoporosis was identified as a predictor of tibial coronal component position (β=0.321, p=0.039).
• Lumbar spine bone mineral density predicted both coronal and sagittal tibial component alignment.

Conclusions:

• Osteoporosis significantly impacts tibial component positioning in computer-assisted navigation TKA.
• Clinicians must be vigilant for potential undetected tracker pin movement in osteoporotic patients.
• Preoperative assessment of bone mineral density may be crucial for optimizing TKA outcomes in at-risk populations.