Preliminary experience with the patient-specific templating total knee arthroplasty

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Medical Technology

Background:

• Total knee arthroplasty (TKA) aims to restore joint function and alignment.
• Conventional intramedullary alignment techniques are standard for TKA.
• Patient-specific templating (PST) offers a novel approach using disposable guides for TKA alignment.

Purpose of the Study:

• To evaluate the efficacy of patient-specific templating (PST) for total knee arthroplasty (TKA).
• To compare PST TKA with conventional intramedullary alignment in terms of blood loss, operation time, and component alignment.
• To assess the accuracy of prosthesis component placement using PST.

Main Methods:

• A case-control study involving 40 consecutive patients undergoing PST TKA.
• Comparison with a matched control group using conventional intramedullary alignment.
• Radiographic assessment of mechanical axis, component alignment (flexion/extension, varus/valgus), and outlier fractions (>3°).

Main Results:

• PST TKA demonstrated a mean mechanical axis of 181° with a 0.3 outlier fraction, compared to 179° and 0.5 for conventional TKA.
• Frontal plane outliers for femoral components were 0.05 (PST) vs. 0.4 (conventional); tibial component outliers were 0.2 (PST) vs. 0.2 (conventional).
• Sagittal plane outliers were 0.4 (PST) vs. 0.9 (conventional) for femoral components and 0.4 (PST) vs. 0.6 (conventional) for tibial components. PST TKA had 10 min shorter operation time and 60 mL less blood loss.

Conclusions:

• Patient-specific templating TKA shows potential for improved alignment accuracy and reduced surgical invasiveness.
• The fraction of outliers in PST TKA was relatively high, necessitating further investigation.
• Larger randomized controlled trials are required to fully evaluate PST TKA and define its clinical role.