We performed a 12-month prospective study on 59 patients (92 knees) who underwent NexGen (Zimmer Inc, Warsaw, IN) cruciate-retaining total knee arthroplasty. In the control group, uncoated components were fixed using screws, whereas the hydroxyapatite–tricalcium phosphate (HA-TCP) group underwent screwless fixation of coated components. At 12 months postoperatively, there was a radiographic clear zone around the femoral and tibial components of 56.5% and 32.6% of the knees in the control group. The HA-TCP group showed a clear zone at the medial aspect of the tibial component in only 1 knee. These results suggested that HA-TCP-coated articular components show good initial fixation without using screws. The NexGen coated knee arthroplasty may be useful for solving the problems of cementless fixation. Copyright 2002, Elsevier Science (USA). All rights reserved.
A prospective study was carried out on the use of a proximally modular, proximal ingrowth noncemented stem in hip revision surgery. There were 109 short stems and 211 long stems. The mean follow-up was 7 years (range, 2–12 years). No revisions were required in the short-stem group for aseptic loosening; 3 (1.4%) revisions were required in the long-stem group. Lucency was absent in 91.7% of short-stem cases, was low grade in 7.2%, and was high grade in 1.1%. In the long-stem group, lucency was absent in 72.9% of cases, was low grade in 24.5%, and was high grade in 2.6%. No measurable subsidence occurred in the short-stem group, and 5 mm of subsidence occurred early in 2 of the long-stem group. This subsidence stabilized subsequently. Osteolysis distal to the sleeve was not observed. A proximal ingrowth, proximally modular stem can be used in revision hip surgery. Copyright 2002, Elsevier Science (USA). All rights reserved.