Low rates of patients meeting return to sport criteria 9 months after anterior cruciate ligament reconstruction: a prospective longitudinal study

Knee Surg Sports Traumatol Arthrosc. 2018 Dec;26(12):3636-3644. doi: 10.1007/s00167-018-4916-4. Epub 2018 Mar 24.


Purpose: The purpose of the current prospective study was to assess the changes over time in patients tested at 6 months and 9 months after anterior cruciate ligament reconstruction (ACLR) with a return to sport (RTS) test battery. It was hypothesized that more patients passed RTS criteria at 9 months compared to 6 months.

Methods: Sixty-two ACLR patients performed a test battery at an average of 6.5 ± 0.7 and 9.5 ± 0.9 months after ACLR. All patients underwent a standardized rehabilitation protocol. The test battery consisted of the following tests: a jump-landing task assessed with the Landing Error Scoring System (LESS), three single-leg hop tasks (single-leg hop test, triple-leg hop test, side hop test), isokinetic quadriceps and hamstring strength at 60, 180 and 300°/s and two questionnaires (IKDC and ACL-RSI). Cut off criteria were set as Limb Symmetry Index (LSI) > 90% (for isokinetic strength and for single-leg hop tasks), LESS < 5, IKDC score within 15th percentage of healthy subjects and ACL-RSI > 56 respectively.

Results: At 6 months, two patients (3.2%) passed all criteria. At 9 months, seven patients (11.3%) passed all criteria. Patients improved in all RTS criteria over time except for the IKDC score. Twenty-nine patients (46.8%) did not pass the strength criterion at 60°/s at 9 months after ACLR.

Conclusions: The percentages of patients passing all RTS criteria were low at both 6 and 9 months after ACLR. Quadriceps strength revealed persistent deficits and the lack of improvement in the IKDC score questionnaires shows insufficient self-reported knee function for RTS.

Level of evidence: III.

Keywords: Anterior cruciate ligament; Hop tests; Movement analysis; Return to sport; Strength.

MeSH terms

  • Adolescent
  • Anterior Cruciate Ligament Reconstruction*
  • Exercise Test
  • Female
  • Humans
  • Longitudinal Studies
  • Male
  • Muscle Strength
  • Prospective Studies
  • Return to Sport*
  • Young Adult