J Knee Surg 2020; 33(01): 084-088
DOI: 10.1055/s-0038-1676567
Original Article
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Is There a Difference between Cemented and Uncemented Femoral Stem Extensions in Revision Knee Arthroplasty?

Paul F. Lachiewicz
1  Chapel Hill Orthopedics Surgery and Sports Medicine, Chapel Hill, North Carolina
2  Department of Orthopedic Surgery, Duke University Medical Center, Durham, North Carolina
,
Jane Ann O'Dell
1  Chapel Hill Orthopedics Surgery and Sports Medicine, Chapel Hill, North Carolina
› Author Affiliations
Further Information

Publication History

26 March 2018

28 October 2018

Publication Date:
18 December 2018 (online)

Abstract

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.