Patient-specific instrumentation does not improve alignment in total knee arthroplasty

Area of Science:

• Orthopedic Surgery
• Biomechanical Engineering
• Medical Device Technology

Background:

• Total knee arthroplasty (TKA) aims to restore limb function and alignment.
• Accurate component positioning is crucial for TKA success.
• Patient-specific instrumentation (PSI) was introduced to enhance surgical precision.

Purpose of the Study:

• To evaluate the efficacy of PSI in improving mechanical leg alignment in TKA.
• To compare the accuracy of PSI versus conventional instrumentation (CI) in TKA.
• To determine if PSI reduces outliers in postoperative limb alignment.

Main Methods:

• Meta-analysis of Level I and Level II studies.
• Inclusion of seven studies with a total of 559 TKA patients.
• Comparison of coronal alignment and outlier rates between PSI and CI groups.

Main Results:

• Mean coronal alignment was similar between PSI (0.78 degrees) and CI (0.81 degrees) groups, both near neutral.
• The PSI group had slightly fewer outliers (21.1%) than the CI group (23.2%).
• The difference in outlier rates was not statistically significant (p=0.59).

Conclusions:

• PSI does not offer a significant advantage in improving postoperative mechanical limb alignment after TKA.
• PSI does not significantly decrease the incidence of alignment outliers compared to CI.
• Current evidence suggests PSI does not substantially enhance alignment accuracy in TKA.