Negative pressure intrusion cementing technique for total knee arthroplasty

Area of Science:

• Orthopedic Surgery
• Biomaterials Science
• Medical Device Engineering

Background:

• Total knee arthroplasty (TKA) relies on robust cement fixation for long-term implant survival.
• Standard cementing techniques may leave voids, potentially compromising cement-bone integrity.
• Alternative methods are sought to optimize cement mantle quality and enhance implant stability.

Purpose of the Study:

• To compare the efficacy of Negative Pressure Intrusion (NPI) versus traditional Positive Pressure Intrusion (PPI) for tibial baseplate cementing in TKA.
• To evaluate the impact of NPI on cement penetration and void formation at the bone-cement interface.
• To assess the potential for NPI to improve biomechanical properties of the cement-bone composite.

Main Methods:

• An in vitro study utilizing six matched pairs of fresh-frozen cadaveric tibiae.
• Tibial surfaces were prepared, cleaned, and dried before cement application.
• Cementing was performed using NPI on one tibia and PPI on its matched pair.
• Radiographic analysis, direct cement depth measurement, and scanning electron microscopy (SEM) were employed for evaluation.

Main Results:

• Radiographs and direct measurements showed no significant difference in cement depth between NPI and PPI.
• SEM analysis revealed consistently fewer voids in the cement-bone composite with NPI.
• NPI specimens demonstrated narrower empty spaces between bone and cement, indicating a tighter fill.

Conclusions:

• Negative Pressure Intrusion (NPI) provides a superior cement fill at the tibial baseplate compared to Positive Pressure Intrusion (PPI).
• The improved fill characteristics achieved with NPI are associated with enhanced biomechanical properties, potentially increasing tensile and shear strength.
• NPI represents a promising advancement in cementing techniques for total knee arthroplasty, aiming for improved long-term implant fixation.