Extract
M.M. Braun, C.E. Zinderman, J.J. Wood, M.A. Malek, F.J. Frassica,
J.A. Polder, and T.R. Cote reply:We appreciate the correspondence of Ms. Budri and colleagues and that of
Drs. Gooding and Bentley as well as the opportunity to address the common
questions they raise regarding the interpretation of adverse event reports
derived from spontaneous (also called passive) reporting systems.Budri et al. suggest that the active nature of the Cartilage Repair
Registry would minimize underreporting. In a qualitative sense, this seems a
reasonable assertion; however, the quantitative importance of the Cartilage
Repair Registry depends at least in part on the numbers of patients enrolled
(as a proportion of all Carticel-treated patients) as well as on the duration
and completeness of their follow-up—data that Budri et al. did not
provide. Provision of these data would allow better estimation of the
significance of the underreporting that we acknowledged to be inherent in our
study design and that Budri et al. downplay. Given the lack of such data, we
refrained from comparing infectious complication rates following Carticel
treatment with other procedures, and we wonder on what quantitative basis
Budri et al. make such comparisons. They also note that our finding about
total knee replacement as an adverse event following Carticel treatment was
not novel, since a report of this had preceded our paper; however, that report
was published subsequent to the submission of our paper to The Journal of
Bone and Joint Surgery. This underscores the fact that knowledge of
product safety evolves over time and that we should be vigilant, particularly
with novel products.