title: Coronal limb alignment and indications for high tibial osteotomy in patients undergoing revision ACL reconstruction.
abstract: BACKGROUND
  Failed ACL reconstruction frequently is accompanied by irreparable medial meniscal tear and/or visible osteoarthritis (OA) in the medial tibiofemoral joint. Thus, assessment for the presence of varus malalignment is important in caring for patients in whom revision ACL reconstruction is considered.
  
  
  OBJECTIVE
  We determined whether patients undergoing revision ACL reconstruction (1) have more frequent varus malalignment coupled with more severe degrees of medial meniscal injury and/or medial tibiofemoral OA, and (2) would meet potential indications for high tibial osteotomy more frequently than patients undergoing primary ACL reconstruction.
  
  
  METHODS
  We compared 58 patients undergoing revision ACL reconstruction and 116 patients undergoing primary ACL reconstruction. The mechanical tibiofemoral angle and the weight loading line (%) of the knee were measured. Additionally, radiographic degrees of OA in the tibiofemoral joints, and meniscal conditions were assessed. Then, proportions of potential candidates for high tibial osteotomy between the two groups were compared based on the following indications: (1) weight loading line less than 5%, (2) weight loading line less than 25% and medial tibiofemoral OA Kellgren-Lawrence Grade 3 or greater, or (3) weight loading line less than 25% and Kellgren-Lawrence Grade 2 medial tibiofemoral OA plus subtotal or total medial meniscectomy status.
  
  
  RESULTS
  The revision ACL reconstruction group had more frequent varus malalignment in terms of proportion of knees with more varus mechanical tibiofemoral angle than varus 5° (19% versus 8%, p = 0.029) and knees with weight loading line less than 25% (22% versus 9%, p = 0.011). This group also had more frequent high-grade injury of the medial meniscus (34% versus 16%, p = 0.007) and tended to have more frequent higher-grade radiographic OA at the medial tibiofemoral joint (19% versus 9%, p = 0.076). The percentage of patients meeting potential indications for high tibial osteotomy was greater in this group (14% versus 2%, p = 0.003).
  
  
  CONCLUSIONS
  We found that many patients undergoing revision ACL surgery may be reasonable candidates for concurrent high tibial osteotomy to address concomitant alignment and OA issues in the medial compartment. However, whether that additional intervention is offset by added risk and morbidity should be the focus of a future study, as it cannot be answered by a study of this design.
authors.affiliation: Joint Reconstruction Center, Seoul National University Bundang Hospital, 166 Gumi-ro, Bundang-gu, Seongnam-si, Gyeonggi-do, (463-707), Republic of Korea.
authors.forename: Ho Hyun
authors.initials: HH
authors.lastname: Won
authors.forename: Chong Bum
authors.initials: CB
authors.lastname: Chang
authors.forename: Min Soo
authors.initials: MS
authors.lastname: Je
authors.forename: Moon Jong
authors.initials: MJ
authors.lastname: Chang
authors.forename: Tae Kyun
authors.initials: TK
authors.lastname: Kim
mesh_terms: D000328:Adult; D059549:Anterior Cruciate Ligament Reconstruction / Q000009:adverse effects / Q000379:methods*; D001696:Biomechanical Phenomena; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D008592:Menisci, Tibial / Q000601:surgery; D020370:Osteoarthritis, Knee / Q000150:complications / Q000503:physiopathology / Q000601:surgery; D010027:Osteotomy / Q000009:adverse effects; D018579:Patient Selection; D011859:Radiography; D012086:Reoperation; D012307:Risk Factors; D013977:Tibia / Q000000981:diagnostic imaging / Q000601:surgery*; D000070600:Tibial Meniscus Injuries; D016896:Treatment Outcome; D016474:Weight-Bearing; D055815:Young Adult