Tendon Graft Healing in Multiligament Reconstructed Knee Detected by FDG-PET/CT: A Pilot Study

Area of Science:

• Orthopedic surgery
• Nuclear medicine
• Medical imaging

Background:

• Assessing graft viability after multiligament knee reconstruction is challenging.
• Magnetic resonance imaging (MRI) provides structural data but not biological activity.
• (18)F-labeled fluorodeoxyglucose positron emission tomography combined with computed tomography (FDG-PET/CT) is a sensitive tool for imaging tissue metabolism.

Purpose of the Study:

• To evaluate the feasibility of FDG-PET/CT for assessing graft metabolism in multiligament reconstructed knees.
• To determine if FDG-PET/CT can detect biological activity of replacement grafts.

Main Methods:

• Seven patients (17-44 years) with multiligament reconstructed knees underwent FDG-PET/CT.
• Fluorodeoxyglucose (FDG) uptake was measured as Standard Uptake Values (SUVs) in graft regions of interest.
• Analysis was performed 3-24 months postoperatively.

Main Results:

• FDG-PET/CT demonstrated increased FDG uptake in all replacement grafts across various follow-up times.
• FDG uptake was significantly higher in the femoral condyles of operated knees compared to contralateral knees.
• This indicates heightened metabolic activity within the grafts.

Conclusions:

• FDG-PET/CT imaging is a feasible method for assessing graft metabolism and viability in the early postoperative period (up to two years).
• A significant increase in tendon graft metabolism is observed during the first two years.
• Further longitudinal studies with larger cohorts are needed to establish the clinical value of FDG-PET/CT.