The migration of a BioScrew as a differential diagnosis of knee pain, locking after ACL reconstruction: a report of two cases.
BACKGROUND
Problems with the initial fixation strength and widening of the femoral and tibial canal after ACL reconstruction using a triple or quadruple semitendinosus autograft have led to the introduction of the so-called Hybrid fixation with the additional use of interference screws. Pain and intraarticular migration have been reported with metal interference screws requiring implant removal (Am J Knee Surg 11:32-34, 2000, Arthroscopy 11:289-291, 1995) but not yet with bioabsorbable screws.


METHODS
We report on two cases were the intraarticular position of a bioabsorbable interference screw possibly due to migration in the early postoperative period lead to symptoms, the need for further surgery, and implant removal.


RESULTS
A preoperative MRI revealed the diagnosis. After removal of the tibial interference screw both knees were settling down, albeit with residual instability and only a moderate clinical result.


CONCLUSIONS
Despite the attractiveness of bioabsorbable screws due to the very fact that they are being reabsorbed over time, there is a slight risk of migration in the first month after the operation. In any suspicious case an MRI will easily clarify the diagnosis.
Krappel
Ferdinand Anton
FA
Orthopädische Klinik, Medizinisches Zentrum Kreis Aachen, Mauerfeldchen 25, 52080 Aachen, Germany. fkrappel@Yahoo.com
Bauer
Eberhardt
E
Harland
Ulrich
U
D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D000070598:Anterior Cruciate Ligament Injuries; D001863:Bone Screws / Q000009:adverse effects*; D003287:Contrast Media; D003937:Diagnosis, Differential; D005548:Foreign-Body Migration / Q000150:complications* / Q000175:diagnosis; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010146:Pain / Q000175:diagnosis*; D011475:Prosthesis Failure; D016059:Range of Motion, Articular; D012086:Reoperation
D003287:Contrast Media