title: Do Patients Failing Return-to-Activity Criteria at 6 Months After Anterior Cruciate Ligament Reconstruction Continue Demonstrating Deficits at 2 Years?
abstract: BACKGROUND
  The variability in outcomes after anterior cruciate ligament reconstruction (ACLR) might be related to the criteria that are used to determine athletes' readiness to return to their preinjury activity level. A battery of return-to-activity criteria (RTAC) that emphasize normal knee function and movement symmetry has been instituted to quantitatively determine athletes' readiness to return to preinjury activities.
  
  
  OBJECTIVE
  To investigate performance-based and patient-reported measures at 12 and 24 months after ACLR between patients who passed or failed RTAC at 6 months after ACLR.
  
  
  METHODS
  Cohort study; Level of evidence, 2.
  
  
  METHODS
  A total of 108 patients who had participated in International Knee Documentation Committee level 1 or 2 sports activities completed RTAC testing at 6, 12, and 24 months after surgery. The RTAC included the isometric quadriceps strength index (QI), 4 single-legged hop tests, the Knee Outcome Survey-activities of daily living subscale (KOS-ADLS), and the global rating scale of perceived function (GRS). Patients who scored ≥90% on all RTAC were classified as the pass group, and those who scored <90% on any RTAC were classified as the fail group. At 12- and 24-month follow-ups, patients were asked if they had returned to the same preinjury activity level.
  
  
  RESULTS
  At the 6-month follow-up, there were 48 patients in the pass group and 47 in the fail group. At the 12-month follow-up, 31 patients (73.8%) from the pass group and 15 patients (39.5%) from the fail group passed RTAC, and at the 24-month follow-up, 25 patients (75.8%) from the pass group and 14 patients (51.9%) from the fail group passed RTAC. The rate of return to activities in the pass group was 81% and 84% at 12 and 24 months after ACLR, respectively, compared with only 44% and 46% in the fail group ( P ≤ .012), respectively; however, some patients in the fail group participated in preinjury activities without being cleared by their therapists. At 12 and 24 months, 60.5% and 48.1% of patients continued to fail again on the criteria, respectively. A statistically significant group × time interaction was found for the single hop and 6-m timed hop limb symmetry indices (LSIs) ( P ≤ .037), with only the fail group demonstrating a significant improvement over time. A main effect of group was detected for the QI and the crossover hop and triple hop LSIs ( P < .01), with patients in the pass group demonstrating higher performance. A main effect of time was detected for the crossover hop and triple hop LSIs and the GRS, with improvements seen in both groups ( P < .05).
  
  
  CONCLUSIONS
  Patients who passed the RTAC early after ACLR were more likely to demonstrate normal knee function and movement symmetry at 12 and 24 months postoperatively, while patients who failed the RTAC early were more likely to demonstrate impaired knee function and movement asymmetry at 12- and 24-month follow-ups. Patients in the pass group had a higher rate of return to their preinjury activity level compared with those in the fail group. A group of patients chose to return to their preinjury activities, even though they were functionally not ready.
authors.affiliation: Biomechanics and Movement Science Program, College of Health Sciences, University of Delaware, Newark, Delaware, USA.|Division of Physical Therapy, Department of Rehabilitation Sciences, Faculty of Applied Medical Sciences, Jordan University of Science and Technology, Irbid, Jordan.
authors.forename: Zakariya
authors.initials: Z
authors.lastname: Nawasreh
authors.affiliation: Department of Physical Therapy, University of the Sciences, Philadelphia, Pennsylvania, USA.|Delaware Rehabilitation Institute, University of Delaware, Newark, Delaware, USA.
authors.forename: David
authors.initials: D
authors.lastname: Logerstedt
authors.affiliation: Biomechanics and Movement Science Program, College of Health Sciences, University of Delaware, Newark, Delaware, USA.|Department of Physical Therapy, College of Health Sciences, University of Delaware, Newark, Delaware, USA.
authors.forename: Kathleen
authors.initials: K
authors.lastname: Cummer
authors.affiliation: Division of Physical Therapy, Department of Rehabilitation Sciences, Faculty of Applied Medical Sciences, Jordan University of Science and Technology, Irbid, Jordan.|Department of Physical Therapy, College of Health Sciences, University of Delaware, Newark, Delaware, USA.|First State Orthopaedics, Newark, Delaware, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Axe
authors.affiliation: Department of Sports Medicine, Norwegian School of Sport Sciences, Oslo, Norway.|Norwegian Research Center for Active Rehabilitation, Oslo, Norway.
authors.forename: May Arna
authors.initials: MA
authors.lastname: Risberg
authors.affiliation: Biomechanics and Movement Science Program, College of Health Sciences, University of Delaware, Newark, Delaware, USA.|Delaware Rehabilitation Institute, University of Delaware, Newark, Delaware, USA.|Department of Physical Therapy, College of Health Sciences, University of Delaware, Newark, Delaware, USA.
authors.forename: Lynn
authors.initials: L
authors.lastname: Snyder-Mackler
mesh_terms: D000203:Activities of Daily Living; D000293:Adolescent; D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D000070598:Anterior Cruciate Ligament Injuries / Q000601:surgery*; D059549:Anterior Cruciate Ligament Reconstruction / Q000379:methods*; D056352:Athletes; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000601:surgery; D008297:Male; D009068:Movement; D052097:Quadriceps Muscle / Q000601:surgery; D013177:Sports; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: anterior cruciate ligament reconstruction; knee function; limb-to-limb symmetry; patient-reported measures; return-to-activity criteria