Thermal Analysis of the Tibial Cement Interface with Modern Cementing Technique

Abstract

Background:The major cause of cemented Total Knee Arthroplasty (TKA) failure is aseptic loosening of the tibial component necessitating revision surgery. Recently, multiple techniques have been described to maximize cement penetration depth and density in the proximal tibia during TKA to potentially avoid early loosening. While cement polymerisation is an exothermic reaction, minimal investigation into the proximal tibial thermal safety margin during cement polymerisation has been undertaken. In animal models osseous injury occurs at temperatures greater than 47 °C when applied for one minute. The aim of this study was to investigate the cement bone interface temperatures in TKA using modern tibial cementing techniques with a cadaveric tibial tray model. Methods:Eight adult cadavers were obtained with the proximal tibial surface prepared by a fellowship trained arthroplasty surgeon. Third generation cementation techniques were used and temperatures during cement polymerization on cadaveric knee arthroplasty models were recorded using thermocouples. Results:The results showed that no tibial cement temperature exceeded 44 °C for more than 1 minute. Two of the eight cadaveric tibias recorded maximum temperatures greater than 44 °C for 55 seconds and 33 seconds, just less than the 60 seconds reported to cause thermal injury. Average maximum polymerization temperatures did not correlate with deeper cement penetration or tray material. Maximum mantle temperatures were not statistically different between metal and all polyethylene tibial trays. Conclusion:Our investigation suggests that modern cementing techniques result in maximum mantle temperatures that are less than previously recorded temperatures required to cause thermal osseous injury, although this thermal injury safety margin is quite narrow at an average of 4.95 °C (95% confidence interval ± 4.31).

Cementing technique for total knee arthroplasty in cadavers using a pastry bone cement

“…The extent of thermal damage is both temperature and time dependent. The present results suggest that the risk of thermal injuries is low, which is in line with previous findings [ 20 ], but the thermal injury safety margin is narrow. It must be emphasized that the measured temperature is different from the real-life situation, since the initial cadaver temperature varied about 10 °C from the temperature of patients.…”

Fracture of the Femoral Component in TKR – A Case Report

“…Presently, it is a rare cause of knee pain after TKR; however, surgeons should remain vigilant and maintain a high index of suspicion with a patient who presents with acute onset pain, evidence of a varus deformity, and concomitant obesity, especially since component fractures can be easily missed on plain radiography [10]. To minimize risk of that rare complication we strongly recommend well performed modern cementing techniques and optimal leg axis in TKR [15].…”

The Effect of Working Time and Application Technique on Cement Penetration into a Tibial Model

“…A cement penetration depth >3 mm is thus considered optimal to resist micromotion and appears integral for stability [15]. Meanwhile, penetration beyond 5 mm has been postulated to risk thermal necrosis to the surrounding bone [15,28]. Cement penetration has been previously described as proportional to bone pore diameter and the square root of applied pressure, while inversely proportional to time after initial cement mixing [20].…”