Tibial component fixation with cement: full- versus surface-cementation techniques.

Despite excellent outcomes with cemented tibial components in total knee arthroplasty, it still is debated whether the tibial stem should be cemented and what the optimal tibial stem design should be. Proponents of full cementation of the tibial stem and component state that better short-term and long-term component fixation is achieved when full cementation is used. Advocates for surface cementation contend that sufficient implant stability is achieved without the increased bone loss that occurs at revision and the stress shielding thought to be linked with cemented stems. This biomechanical cadaver study compared initial fixation and cement penetration depth in fully cemented versus surface cemented tibial trays with two different stem geometries (cruciate and I-beam) and compared two stem designs (cruciate and I-beam) fixed with surface cementation. Under an eccentric load, simulating three times body weight for 6000 cycles, there seems to be no difference in the micromotion of either tibial component implanted with surface or full cementation. Additionally, no difference in the average depth of cement penetration was detected between fixation techniques or stem types. The initial fixation stability of the surface cement technique seems correlated to the depth of cement penetration into proximal tibial surface. The current data support other studies which indicate that stability of surface-cemented tibial components may be related to the depth of cement penetration.