Background: Osteolysis and increased polyethylene wear have been
reported in association with several designs of modular total knee prostheses.
The purpose of the present study was to evaluate a modular posterior
stabilized prosthesis to determine its clinical performance as well as the
rates of component loosening and osteolysis.
Methods: We performed a prospective, consecutive study of 193 knees
in 131 patients who were managed with the modular Insall-Burstein II posterior
stabilized total knee prosthesis by one surgeon. The mean age of the patients
at the time of surgery was sixty-eight years, and the mean duration of
follow-up was seven years (range, five to fourteen years). Clinical evaluation
was performed with use of standard knee-scoring systems. Radiographs were
evaluated for the presence of radiolucent lines, osteolysis, and
Results: The overall result (as determined with the Hospital for
Special Surgery scoring system) was rated as excellent for 112 knees, good for
sixty, fair for fifteen, and poor for six. The mean postoperative flexion was
112°. No clinical or radiographic loosening of the tibial component was
noted. Eight knees had osteolytic lesions of the tibia. Thin, incomplete,
nonprogressive radiolucent lines were noted around thirty tibial components
(16%). There were three reoperations.
Conclusions: Despite previous reports of osteolysis, polyethylene
wear, and loosening in association with some modular total knee implant
designs, there was no loosening in this series of posterior stabilized total
knee replacements and only eight knees had tibial osteolysis after a mean
duration of follow-up of seven years. We believe that total knee
arthroplasties that are performed with use of cemented modular posterior
stabilized components can have a high rate of intermediate-term success.
Level of Evidence: Therapeutic study, Level IV (case
series [no, or historical, control group]). See Instructions to Authors for a
complete description of levels of evidence.