title: Anterior cruciate ligament reconstruction using biodegradable transfemoral fixation at 5-year follow-up: clinical and magnetic resonance imaging evaluation.
abstract: OBJECTIVE
  Biodegradable transfemoral graft fixation devices used in anterior cruciate ligament (ACL) reconstruction have recently been reported to precociously lose structural integrity.
  
  
  METHODS
  This study investigated outcomes after ACL reconstruction using hamstring grafts and biodegradable transfemoral fixation at 5-year follow-up. The condition of both graft and fixation device was evaluated by magnetic resonance imaging (MRI) and related to clinical outcomes. In total, 85 patients on whom index ACL reconstructive surgery by means of a quadrupled semitendinosus-gracilis graft and biodegradable transfemoral fixation was performed were included in the study.
  
  
  RESULTS
  Fifty-nine patients could be assessed by clinical and MRI examinations at a mean follow-up of 61 months (range, 52-69 months). Completely intact pins were found in 17 patients (29%), intact pins with delicate areas of resorption in 8 patients (14%), pin deformation in 5 patients (8%), pin fracture in 22 patients (37%) and pin migration in 3 patients (5%). In 40 patients (68%), pins had undergone degradation at the graft suspension point. Hamstring graft integrity and signal intensity scores were found to be significantly higher in patients with deformed, broken or dislocated pins as compared to patients with fully or mainly intact pins. Clinically, the mean side-to-side difference in anterior-posterior-laxity was 1.1 ± 1.6 mm, while Lysholm, IKDC and Tegner scores were 89 ± 11, 84 ± 14 and 4 (1-9). No statistically significant correlation was found between pin condition and clinical outcomes.
  
  
  CONCLUSIONS
  Biodegradable fixation pins lose structural integrity in a way that suggests continuous loading of the pin/graft construct, thereby questioning osseous incorporation of the graft. This situation is clinically relevant in terms of improved graft condition.
  
  
  METHODS
  Retrospective case series, Level III.
authors.affiliation: Department of Rheumatology and Arthroscopy, Marienkrankenhaus Düsseldorf-Kaiserswerth, An St. Swidbert 17, 40489, Düsseldorf, Germany. Nebelung@vkkd-kliniken.de
authors.forename: Sven
authors.initials: S
authors.lastname: Nebelung
authors.forename: Gregor
authors.initials: G
authors.lastname: Deitmer
authors.forename: Rolf
authors.initials: R
authors.lastname: Gebing
authors.forename: Frank
authors.initials: F
authors.lastname: Reichwein
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Nebelung
mesh_terms: D020341:Absorbable Implants; D000293:Adolescent; D000328:Adult; D059549:Anterior Cruciate Ligament Reconstruction / Q000295:instrumentation* / Q000379:methods; D001858:Bone Nails; D001863:Bone Screws; D005260:Female; D005269:Femur / Q000473:pathology / Q000601:surgery*; D005500:Follow-Up Studies; D005548:Foreign-Body Migration / Q000473:pathology; D006801:Humans; D007719:Knee Joint / Q000473:pathology / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011475:Prosthesis Failure; D012189:Retrospective Studies; D013710:Tendons / Q000473:pathology / Q000637:transplantation; D013977:Tibia / Q000473:pathology / Q000601:surgery; D055815:Young Adult