title: Femoral tunnel widening after quadrupled hamstring anterior cruciate ligament reconstruction.
abstract: OBJECTIVE
  To evaluate the extent of femoral tunnel widening after quadrupled hamstring anterior cruciate ligament reconstruction using femoral cross pin fixation in contrast to bioabsorbable screw fixation augmented with Endopearl.
  
  
  METHODS
  16 patients underwent cross pin femoral fixation and the next 15 underwent bioabsorbable screw fixation augmented with Endopearl. The patients were evaluated radiographically for femoral tunnel widening. Standard posteroanterior radiographs of the knee in full extension were taken at postoperative year 2 and 5. The tunnel width was measured at the opening, the widest and the most proximal parts of the femoral tunnel.
  
  
  RESULTS
  In the femoral cross pin and bioabsorbable screw fixations, the mean femoral tunnel sizes were 7.6 and 8.0 mm, respectively. The overall mean tunnel widening at all measured sites were 2.7 and 1.8 mm at the 2-year follow-up and were 2.5 and 1.8 mm at the 5-year follow-up, respectively. The femoral tunnel widening was greater in the cross pin than the bioabsorbable screw group, but only the difference in the most proximal part was significant (p=0.01 at year 2 and p<0.001 at year 5).
  
  
  CONCLUSIONS
  Femoral tunnel widening was greater in femoral cross pin fixation, probably related to the windshield-wiper and bungee-cord effects. It usually occurred in the first 2 years after the operation and remained static thereafter.
authors.affiliation: Department of Orthopaedics and Traumatology, Kwong Wah Hospital, Kowloon, Hong Kong. phycheung@gmail.com
authors.forename: Philip
authors.initials: P
authors.lastname: Cheung
authors.forename: Wai-lam
authors.initials: WL
authors.lastname: Chan
authors.forename: Chi-hung
authors.initials: CH
authors.lastname: Yen
authors.forename: Sze-chung
authors.initials: SC
authors.lastname: Cheng
authors.forename: Siu-bon
authors.initials: SB
authors.lastname: Woo
authors.forename: Tsz-kau
authors.initials: TK
authors.lastname: Wong
authors.forename: Wing-cheung
authors.initials: WC
authors.lastname: Wong
mesh_terms: D020341:Absorbable Implants; D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D000070598:Anterior Cruciate Ligament Injuries; D001858:Bone Nails; D001863:Bone Screws; D005260:Female; D005269:Femur / Q000601:surgery*; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D019651:Plastic Surgery Procedures / Q000295:instrumentation*; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome