A review was made of two series of CLS cups, fixed by expansion and an
choring in the acetabular periphery, in order to ascertain the usefuln
ess of the International Documentation and Evaluation System. One hund
red and fifty cases, from a series of 180, were documented and implant
ed by the same surgical team in Barcelona. The provisional results are
described with a follow up of between one and 5 or more years. These
were compared with 625 cases documented in the Berne Foundation with a
similar follow up. The results were similar and the series studied is
justified because of its documentary accuracy. The possible advantage
s of the CLS cup are discussed.