Study highlights importance of ACL reconstruction for youth at high risk of knee re-injury

Sport Medicine Centre researchers find patellar tendon reconstruction can protect active youth from early osteoarthritis.

Dr. Nick Mohtadi, Professor, Faculty of Kinesiology and Director, Sports Medicine Centre, led a clinical trial with Dana Hunter, Research Assistant, and Denise Chan, Research Coordinator, which highlights the importance of Anterior Cruciate Ligament (ACL) reconstruction for youth at high risk of knee reinjury. UCalgary

By Faculty of Kinesiology Staff, University of Calgary June 27, 2019

Anterior cruciate ligament (ACL) rupture, one of the most common types of knee injury, usually affects active, young adults, and requires reconstructive surgery to regain knee stability.

A new randomized clinical trial [1] by researchers at the Faculty of Kinesiology Sport Medicine Centre measured the outcomes of patients at five years after receiving ACL reconstructive surgery with one of three different graft types. The graft is a piece of tendon from either the patient’s own patellar tendon (which attaches the kneecap to the shin bone) or hamstring muscle.

The study shows that a patient’s quality of life is the same at five years, regardless of the graft type used. However, the study also shows that ACL reconstruction with a specific graft type, patellar tendon, is recommended for younger patients who have a high risk of reinjury. Previously, ACL reconstruction was guided by the surgeon’s choice, “Dr. Google,” and sometimes patient preference, with inconclusive scientific evidence to support the optimal graft choice.

Preventing earlier onset of osteoarthritis

“This study has taught us to focus on young athletes who play sports like football, basketball and soccer, and graft type makes a difference in these high-risk individuals. Even more important is protecting the menisci (cartilage shock absorbers). Young, active patients who have ACL tears that are untreated typically damage their menisci, leading to the chance of earlier osteoarthritis development,” says Dr. Nicholas Mohtadi MD, medical director of the Sport Medicine Centre; clinical professor, Department of Surgery, Cumming School of Medicine; adjunct professor, Faculty of Kinesiology; and McCaig Institute for Bone and Joint Health.

A ligament is a structure that joins two bones, and in a way, the patellar tendon is more like a ligament because it joins the kneecap to the shin bone.

This randomized clinical trial compares patient outcomes following ACL reconstruction with either a patellar tendon, single-bundle hamstring tendon, and double-bundle hamstring tendon graft.

Five-year clinical trial has ‘remarkable’ followup rate

Three-hundred-and-thirty patients were randomly assigned to undergo one of these three procedures. The disease-specific Anterior Cruciate Ligament Quality of Life (ACL-QOL) outcome, other clinical outcomes, and traumatic ACL re-injuries were compared at five years following the ACL reconstruction.

A total of 315 patients (95 per cent) completed their five-year followup study visit. ACL-QOL scores increased significantly from pre-surgery to five years post-surgery. The ACL-QOL scores for each group at five years were similar. Researchers found a normal to nearly normal knee function and better rotational stability trending in favour of the patellar tendon group, compared with the hamstring and double-bundle groups.

It is rare to be able to capture detailed information at five years after surgery. The worldwide gold standard is to achieve 80 per cent followup; this study has greatly surpassed that rate.

“This remarkable follow-up rate is a direct reflection of our research assistants and the staff at the Sport Medicine Centre. Without their support, dedication and engaging attitudes, this would not have been possible,” says Mohtadi.

Five-year comparison of three ACL reconstruction grafts, Mohtadi, et al. 2019 J Bone Joint Surg Am.[1]

The Sport Medicine Centre in the Faculty of Kinesiology provides quality care in physiotherapy, massage therapy, athletic therapy, performance nutrition and X-ray services alongside a team of sport medicine physicians and orthopaedic surgeons. It is the hub of sport medicine research since being established at the University of Calgary during the 1988 Winter Olympic Games. It delivers integrated care to elite and recreational athletes on campus and in the community. Find out more.

Source University of Calgary


The Journal of Bone and Joint Surgery, Editage Research Communication. TJBJS 70 VIDEO. Youtube Jun 3, 2019
  1. A Randomized Clinical Trial Comparing Patellar Tendon, Hamstring Tendon, and Double-Bundle ACL Reconstructions: Patient-Reported and Clinical Outcomes at 5-Year Follow-up, Mohtadi NG, Chan DS. J Bone Joint Surg Am. 2019 Jun 5;101(11):949-960. doi: 10.2106/JBJS.18.01322.
  2. Effect of stochastic resonance on proprioception and kinesthesia in anterior cruciate ligament reconstructed patients, Zandiyeh P, Küpper JC, Mohtadi NGH, Goldsmith P, Ronsky JL. J Biomech. 2019 Feb 14;84:52-57. doi: 10.1016/j.jbiomech.2018.12.018. Epub 2018 Dec 16.
  3. A Randomized Clinical Trial Comparing Patellar Tendon, Hamstring Tendon, and Double-Bundle ACL Reconstructions: Patient-Reported and Clinical Outcomes at a Minimal 2-Year Follow-up, Mohtadi N, Chan D, Barber R, Oddone Paolucci E. Clin J Sport Med. 2015 Jul;25(4):321-31. doi: 10.1097/JSM.0000000000000165.
  4. Reruptures, Reinjuries, and Revisions at a Minimum 2-Year Follow-up: A Randomized Clinical Trial Comparing 3 Graft Types for ACL Reconstruction, Mohtadi N, Chan D, Barber R, Paolucci EO. Clin J Sport Med. 2016 Mar;26(2):96-107. doi: 10.1097/JSM.0000000000000209.
  5. A systematic review of peroneal nerve palsy and recovery following traumatic knee dislocation, Woodmass JM, Romatowski NP, Esposito JG, Mohtadi NG, Longino PD. Knee Surg Sports Traumatol Arthrosc. 2015 Oct;23(10):2992-3002. doi: 10.1007/s00167-015-3676-7. Epub 2015 Jun 27. Review.
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