Is Cement Mantle Thickness a Primary Cause of Aseptic Tibial Loosening Following Primary Total Knee Arthroplasty?

Abstract

Background: Aseptic tibial loosening following primary total knee replacement is one of the leading causes of long-term failure. Cement mantle thickness has been implicated as a source of aseptic tibial loosening. Therefore, the following study was designed to determine (1) what is the cement mantle thickness in patients that develop aseptic tibial loosening, and (2) is there a difference in cement mantle thickness based on the interface of failure? 

Method: This retrospective cohort included 216 patients revised for aseptic tibial loosening. Patient demographics, operative data, and clinical outcomes were recorded. A preoperative radiographic assessment was performed to determine the interface of failure and the thickness of the cement mantle using the Knee Society Radiographic Evaluation System zones.


Results: The average patient age was 65 years and body mass index was 33.7 kg/m2. 203 patients demonstrated radiographic failure at the implant-cement interface and thirteen patients demonstrated failure at the cement-bone interface. The average cement mantle thickness of each radiographic zone for the entire cohort on the AP and lateral views was 4.4 and 4.5 mm, respectively. The average cement mantle thickness of patients that developed failure at the implant-cement interface was significantly greater than patients that failed at the cement-bone interface in each radiographic zone (p<0.001). 

Conclusions: Patients that develop implant loosening at the cement-bone interface were noted to have a significantly decreased cement mantle compared to patients that failed at the implant-cement interface. Methods for decreasing tibial implant loosening should likely focus on improving the fixation at the implant-cement interface.

Note:
Funding Information: None.

Conflict of Interests: Stephen M. Engstrom, MD reports a relationship with BoneSupport that includes: consulting or advisory. Stephen M. Engstrom, MD reports a relationship with DJO Surgical that includes: consulting or advisory. Stephen M. Engstrom, MD reports a relationship with American Association of Hip and Knee Surgeons that includes: board membership. Stephen M. Engstrom, MD reports a relationship with American Academy of Orthopaedic Surgeons that includes: board membership. Andrew Shinar, MD reports a relationship with Southern Orthopedic Association that includes: board membership. J. Bohannon Mason, MD reports a relationship with American Association of Hip and Knee Surgeons that includes: board membership. J. Bohannon Mason, MD reports a relationship with DePuy Synthes that includes: consulting or advisory, equity or stocks, and funding grants. John R. Martin, MD reports a relationship with DePuy Synthes that includes: consulting or advisory and paid expert testimony. J. Bohannon Mason, MD reports a relationship with MedEnvision that includes: consulting or advisory. J. Bohannon Mason, MD reports a relationship with Arthroplasty Today that includes: board membership. Co-author receives royalties from Smith and Nephew - Andrew Shinar, Co-author receives royalties from DePuy Synthes - J. Bohannon Mason, Co-author receives royalties/financial support from Elsevier, Journal of Arthroplasty - J. Bohannon Mason

Ethical Approval: The following project was approved by the OrthoCarolina Institutional Review Board.

Keywords: implant fixation, aseptic failure, aseptic tibial loosening