Purpose Although bioabsorbable screws promise to
degrade within months up to several years after implantation,
often this does not happen. In fact, other problems such as
screw breakage, tunnel enlargement, allergic or foreign body
reactions, cyst or abscess formation, and delayedmigration of
‘‘biodegradable’’ screws have been reported. This study aims
to provide relevant basic science knowledge and recent
insights concerning ‘‘biomaterials’’ currently used in fixation
devices for anterior cruciate ligament (ACL) repair. A systematic
reviewon the topic of screw ‘‘migration’’ is provided.
Methods A PubMed search combining all the key terms
was done looking for complications related to late migration
of ‘‘bioabsorbable’’ screws used in ACL reconstruction
without inferior time limitation up to January 2012. Only
clinical reports were included. Reference lists of reports
were checked to detect others not identified by the original
search. A pre-publication search was performed to identify
the most recent relevant articles.
Results A total of ten articles referred to migration of
‘‘bioabsorbable’’ interference screws. Most cases reported
on poly-L-lactic acid-based screws. Migration was noticed
between 3 and 22 months postoperatively. It was noticed
both in the tibia and the femur and with the application of
several types of graft.
Conclusion Migration is a possible complication of
‘‘bioabsorbable’’ interference screws. The information
related to all clinical implications of the so-called ‘‘biodegradable
screws’’ remains scarce and probably suffers
from the phenomenon of publication bias. The complexity
of possible reactions occurring in the human body is difficult
to reproduce under controlled laboratory conditions.
Level of evidence Systematic review including casereports,