title: Interval arthrometric comparison of anterior cruciate ligament reconstruction using bone-patellar tendon-bone autograft versus allograft: do grafts attenuate within the first year postoperatively?
abstract: BACKGROUND
  There is little information regarding the incremental changes in the postoperative laxity of patellar tendon (PT) autografts versus allografts in anterior cruciate ligament (ACL) reconstruction.
  
  
  OBJECTIVE
  (1) There would be no significant increase in laxity between 6 weeks and 1 year postoperatively with PT autografts or allografts, (2) there would be no significant difference in laxity between PT autografts and allografts, (3) there would not be a significant difference in laxity between nonirradiated and low dose-irradiated PT allograft tissues, and (4) the physical examination findings would correlate with the instrumented laxity outcomes.
  
  
  METHODS
  Cohort study; Level of evidence, 3.
  
  
  METHODS
  A retrospective review of 238 ACL-deficient patients who underwent single-incision endoscopic ACL reconstruction with a PT autograft (n = 132) or allograft (n = 106; 58 irradiated and 48 nonirradiated) from a single surgeon was made looking at data from preoperatively and from 6 weeks to 1 year postoperatively. The objective measurements of ligament integrity included range of motion, Lachman test, pivot-shift test, and KT-1000 arthrometer instrumented laxity examination. Failure was defined as arthrometric side-to-side differences (maximum manual difference) ≥3 mm or a positive pivot shift. Statistical significance was defined as P < .05.
  
  
  RESULTS
  There were no differences in postoperative examination findings or instrumented laxity between PT autografts and allografts (irradiated or nonirradiated) in either subgroup. The postoperative improvement based on the Lachman examination, pivot-shift test, and arthrometric data in all study groups was significant (P < .001) in 98% (autograft: n = 130; allograft: n = 104) of patients, and arthrometric failure correlated with failure by physical examination. There was no significant change in graft laxity, as measured by KT-1000 arthrometer, from 6 weeks to 1 year postoperatively for 98% of patients. Finally, there was no statistical correlation in instrumented laxity results for either the autograft or allograft group with reference to age, gender, concurrent meniscectomy, meniscal repairs, interval to surgery, postoperative patellar pain, time to surgery, or irradiated versus nonirradiated allograft.
  
  
  CONCLUSIONS
  Laxity is not increased after the initial 6 weeks for either PT allograft or autograft constructs during the first postoperative year. There was no correlation between age, gender, concomitant injury, interval to surgery, or radiation of the graft with instrumented laxity results. Furthermore, our arthrometric data paralleled our clinical findings of stability at follow-up.
authors.affiliation: Rush University Medical Center, Department of Orthopedic Surgery, Division of Sports Medicine, 1611 West Harrison Street, Suite 300, Chicago, IL 60612, USA.
authors.forename: Neil S
authors.initials: NS
authors.lastname: Ghodadra
authors.forename: Nathan A
authors.initials: NA
authors.lastname: Mall
authors.forename: Robert
authors.initials: R
authors.lastname: Grumet
authors.forename: Seth L
authors.initials: SL
authors.lastname: Sherman
authors.forename: Spencer
authors.initials: S
authors.lastname: Kirk
authors.forename: Matthew T
authors.initials: MT
authors.lastname: Provencher
authors.forename: Bernard R
authors.initials: BR
authors.lastname: Bach
mesh_terms: D000293:Adolescent; D000328:Adult; D059549:Anterior Cruciate Ligament Reconstruction / Q000379:methods*; D050376:Bone-Patellar Tendon-Bone Grafting / Q000379:methods*; D002648:Child; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000503:physiopathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D016059:Range of Motion, Articular / Q000502:physiology; D012189:Retrospective Studies; D014182:Transplantation, Autologous; D014184:Transplantation, Homologous; D016896:Treatment Outcome; D055815:Young Adult