A stem is usually recommended for the femoral component in revision total knee arthroplasty (TKA) for reasons of alignment, fixation, and bone loss. However, the optimal method of fixation for the femoral component stem remains controversial. We queried the prospective revision TKA database of one surgeon and performed a clinical and radiographic evaluation of 84 knee revisions in which a femoral component stem extension was implanted. There was no established protocol for fixation of the femoral stem during this time. There were 34 knees with cemented (C) fixation and 50 with uncemented (UC) fixation. There were no significant differences in age, gender, body mass index (BMI), or Anderson's Orthopaedic Research Institute (AORI) defect between the two groups. Patients were evaluated using the classic Knee Society clinical and radiographic scores and followed for a mean of 6 years (range: 2–17 years). There was no statistically significant difference in prevalence of reoperation for loosening between cemented and uncemented stems (cemented 3.3% vs. uncemented 10%; p = 0.4). Post hoc power analysis showed that 203 knees in each group would be needed for statistical significance. With the numbers available, there was no difference in aseptic component loosening and radiographic loosening combined (one revision and two radiographic loosening, 9%, in the C group vs. five revisions and three radiographic loosening, 16%, in the UC group; p = 0.51). There was no difference between the groups in the overall rate of any reoperation. There were no differences in postoperative Knee Society pain score, change in pain score, Knee Society function score, or change in function score. Due to the numbers required, a large multicenter study will be needed to determine the optimal method of fixation of the femoral stem in revision TKA.

Aims There is insufficient evidence to recommend the use of alternative polyethylene bearings in modular, fixed-bearing total knee arthroplasty (TKA). The purpose of this study was to compare standard polyethylene (SP) and highly crosslinked polyethylene (XLP) tibial liners in posterior-stabilized TKA, with osteolysis as the primary outcome and clinical results and the rate of re-operation as the secondary outcomes. Patients and Methods This is a single-surgeon, prospective randomized study involving one design of modular posterior-stabilized TKA. An analysis of 122 TKAs with an SP compression moulded liner and 123 with an XLP liner was performed, with a mean follow-up of six years (2 to 11). Patients were evaluated clinically using the Knee Society score, Lower Extremity Activity Score (LEAS), and the presence of an effusion, and standard radiographs were assessed for radiolucent lines and osteolytic lesions. Results Osteolysis was present in four TKAs (3.3%) in the SP group, and no knees in the XLP group (p = 0.06). There were no significant differences between the Knee Society total score, change in total score, knee function score, change in function score, LEAS, and change in LEAS in the two groups. There was a significant difference in the presence of an effusion (10/122 with SP liners, 1/123 with XLP liners; p = 0.02). There was no significant difference in the rate of re-operation between the two groups (p = 0.36). There were no complications related to the XLP liner. Conclusion At this length of follow-up, there were no advantages and no complications related to the use of this XLP tibial liner. The presence of effusion and small osteolytic lesions was more frequent with SP than XLP liners, but of unknown clinical significance. Cite this article: Bone Joint J 2019;101-B(7 Supple C):33–39