title: Tunnel widening prevention with the allo-Achilles tendon graft in anterior cruciate ligament reconstruction: Surgical tips and short term followup.
abstract: BACKGROUND
  Tunnel widening (TW) after anterior cruciate ligament (ACL) reconstruction can be a serious complication, and there is controversy over how to prevent it. This study aimed to suggest surgical approaches to prevent TW using an allo-Achilles tendon graft, and then to evaluate TW after these surgical tips were applied.
  
  
  METHODS
  Sixty two patients underwent ACL reconstruction with an allo-Achilles tendon graft. Four surgical approaches were used: Making a tibial tunnel by bone impaction, intraarticular reamer application, bone portion application for the femoral tunnel, and an additional bone plug application for the tibial tunnel. After more than 1-year, followup radiographs including anteroposterior and lateral views were taken in 29 patients encompassing thirty knees. The diameter of the tunnels at postoperation day 1 (POD1) and at followup was measured and compared.
  
  
  RESULTS
  In 18 knees (60%), there were no visible femoral tunnel margins on the radiographs at POD1 or followup. In the other 12 cases, which had visible femoral tunnel margins on followup radiographs, the mean femoral tunnel diameter was 8.6 mm. In the tibial tunnel, the mean diameters did not increase on all three levels (proximal, middle, and distal), and there was no statistically significant difference between the diameters at POD1 and followup.
  
  
  CONCLUSIONS
  The suggested tips for surgery involving an allo-Achilles tendon graft can effectively prevent TW after ACL reconstruction according to this case series. These surgical tips can prevent TW.
authors.affiliation: Joint Center, Barunsesang Hospital, Seongnam-si, Gyeonggi-do, Seoul, Korea.
authors.forename: Dong Won
authors.initials: DW
authors.lastname: Suh
authors.affiliation: Department of Orthopedic Surgery, Korea University Anam Hospital, Korea University College of Medicine, Seoul, Korea.
authors.forename: Seung Beom
authors.initials: SB
authors.lastname: Han
authors.affiliation: Joint Center, Barunsesang Hospital, Seongnam-si, Gyeonggi-do, Seoul, Korea.
authors.forename: Woo Jin
authors.initials: WJ
authors.lastname: Yeo
authors.affiliation: Joint Center, Barunsesang Hospital, Seongnam-si, Gyeonggi-do, Seoul, Korea.
authors.forename: Won Hee
authors.initials: WH
authors.lastname: Lee
authors.affiliation: Joint Center, Barunsesang Hospital, Seongnam-si, Gyeonggi-do, Seoul, Korea.
authors.forename: Jae Ho
authors.initials: JH
authors.lastname: Kwon
authors.affiliation: Joint Center, Barunsesang Hospital, Seongnam-si, Gyeonggi-do, Seoul, Korea.
authors.forename: Bong Soo
authors.initials: BS
authors.lastname: Kyung
keywords: Allo-Achilles tendon graft; Anterior cruciate ligament; achilles tendon; allograft; anterior cruciate ligament; anterior cruciate ligament reconstruction; tunnel widening