title: Loss of extension following anterior cruciate ligament reconstruction: analysis of incidence and etiology using IKDC criteria.
abstract: OBJECTIVE
  The purpose of this study was to determine the incidence of and factors associated with loss of extension (LOE) 4 weeks after anterior cruciate ligament (ACL) reconstruction using the new IKDC Knee Ligament Evaluation Form criteria for loss of motion.
  
  
  METHODS
  A retrospective review of patients who had undergone arthroscopic ACL reconstruction between 1995 and 2000 was performed. An endoscopic single tunnel technique with autograft or allograft was used in all cases. A standardized physical therapy program was prescribed to all patients. Subjects with revision ACL reconstruction, concomitant ligament surgery, meniscal transplantation, or any articular cartilage surgery were excluded. LOE was defined as greater than a 5 degrees side-to-side difference in passive knee extension 4 weeks after surgery, the need for repeat arthroscopy to restore extension, or use of a drop-out cast to restore extension.
  
  
  RESULTS
  Fifty-eight of 229 (25.3%) patients developed LOE 4 weeks after ACL reconstruction. LOE was not associated with age, sex, presence of nerve block, concomitant meniscal procedures, specific graft type, or tourniquet time (P > .05). LOE was significantly associated with preoperative extension, time from injury to surgery, and use of autograft (P < .05). Twenty-eight (12.2%) patients underwent an arthroscopic procedure to recover loss of motion. Following arthroscopy, 4 (1.7%) patients had passive motion deficits between 6 degrees and 10 degrees , with none greater than 10 degrees .
  
  
  CONCLUSIONS
  Preoperative range of motion and time to surgery are intimately related to a patient's postoperative extension. While 48% of patients that lacked full extension by 4 weeks eventually required arthroscopic debridement to achieve satisfactory extension, our treatment algorithm led to an overall incidence of LOE greater than 5 degrees at final follow-up of 1.7%.
  
  
  METHODS
  Level III, therapeutic, retrospective, comparative study.
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
authors.forename: Craig S
authors.initials: CS
authors.lastname: Mauro
authors.forename: James J
authors.initials: JJ
authors.lastname: Irrgang
authors.forename: Brian A
authors.initials: BA
authors.lastname: Williams
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Harner
mesh_terms: D000293:Adolescent; D000328:Adult; D000465:Algorithms; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D000070598:Anterior Cruciate Ligament Injuries; D053587:Arthrometry, Articular; D001182:Arthroscopy; D016009:Chi-Square Distribution; D002648:Child; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D016059:Range of Motion, Articular / Q000502:physiology*; D019651:Plastic Surgery Procedures / Q000379:methods*; D012189:Retrospective Studies; D012307:Risk Factors; D018709:Statistics, Nonparametric; D016896:Treatment Outcome