Purpose
The aim of the current study was to determine the effect of the knee flexion angle
(KFA) during tibial anterior cruciate ligament (ACL) graft fixation on patient-reported
outcomes, graft stability, extension loss, and reoperation after anatomic single-bundle
ACL reconstruction.
Methods
All 169 included patients (mean age 28.5 years, 65% male) were treated with anatomic
single-bundle ACL reconstruction using patellar tendon autograft and were randomized
to tibial fixation of the ACL graft at either 0° (n = 85) or 30° (n = 84). The primary
outcome was the Knee Injury and Osteoarthritis Outcome Score (KOOS) 2 years after
surgery. Secondary outcomes were the Marx Activity Scale (MAS), the rate of reoperation,
and physical examination findings at 1 year, including KT-1000 and side-to-side differences
in knee extension.
Results
The follow-up rate was 82% (n = 139) for the primary outcome. Graft failure rate at
2 years was 1% (n = 2, 1 per group). ACL tibial graft fixation at 0° or 30° did not
have a significant effect on KOOS scores at 2 years after ACLR. Patients whose graft
was fixed at a knee flexion angle of 0° had greater scores on the MAS (mean 9.6 95%
confidence interval [CI] 8.5 to 10.6, versus 8.0, 95% CI 6.9 to 9.1; P = .04), and a greater proportion achieved the minimal clinical important difference
(MCID) for the KOOS pain subdomain (94% versus 81%; P = .04). There was no significant difference in knee extension loss, KT-1000 measurements,
or reoperation between the 2 groups.
Conclusion
In the setting of anatomic single-bundle ACLR using patellar tendon autograft and
anteromedial portal femoral drilling, there was no difference in KOOS scores between
patients fixed at 0° and 30°. Patient fixed in full extension did demonstrate higher
activity scores at 2 years after surgery and a greater likelihood of achieving the
MCID for KOOS pain.
Level of Evidence
II, prospective randomized trial
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Article Info
Publication History
Published online: December 21, 2021
Accepted:
December 12,
2021
Received:
April 16,
2021
See commentary on page 1978Footnotes
This study was funded by a 2014 AANA Research Grant
The authors report that they have no conflicts of interest in the authorship and publication of this article. Full ICMJE author disclosure forms are available for this article online, as supplementary material.
Registered at Clinicaltrials.gov: NCT03875807.
Identification
Copyright
© 2021 by the Arthroscopy Association of North America
