An interventional study of QT graft and ST/Gr graft in ACL - Anterior Cruciate Ligament Rupture, sponsored by Hvidovre University Hospital. Recruiting at 1 site in Denmark. Open to participants aged 18 Years to 40 Years. Per ClinicalTrials.gov, last updated 2025-08-28.
Sponsored by Hvidovre University Hospital · Not applicable, Interventional, and Treatment
Purpose:
To investigate the differences between the three most common methods for reconstruction of the anterior cruciate ligament (ACL), to support the development of the best method for the individual patient.
Main research area: ¨ Sports Orthopedic Surgical research.
State of the art:
Every year in Denmark 2500 patients receive surgical reconstruction surgery to replace a ruptured ACL. Many patients experience a decline in knee function and 4-12% suffer a new ACL rupture within 5 years. According to data from the Danish ACL register, three methods of reconstruction are most prevalent, but with large variation between hospitals. This indicates lack of consensus on optimal surgical procedure.
Design:
Assessor-blinded randomized controlled study. 150 patients aged 18-40 with ruptured ACL are allocated to reconstruction with tendon(s) harvested from either the semitendinosus and gracilis, or the patella tendon, or the quadriceps tendon. Patient follow-up will be conducted preoperatively and 1, 6, 12, 24 months postoperatively.
Primary technologies and outcomes:
The trial is designed for publication in three primary publications
Additional secondary publications are in the pipeline. Reference to primary protocol and results will always be emphasized in secondary publication to ensure methodological transparency.
Purpose:
The aim of this randomized controlled trial is to investigate the effect of graft choice in anterior cruciate ligament (ACL) reconstruction surgery, primarily from a patient-centered as well as a novel biomechanical perspective; and secondly from a clinical and muscle morphological perspective.
The study compares the three most common methods for ACL reconstruction: autograft harvested from the m. quadriceps tendon (QT), the hamstring tendons (ST/Gr), and the patella tendon (BPTB).
By applying this 360° scientific approach, it is the hope to improve the possibilities for a much-needed evidence-based and individualized treatment of ACL ruptures.
Objectives and hypotheses:
The investigators hypothesize that of all three grafts, the QT graft will result in non-inferior patient reported knee function.
State-of-the-art:
The most common method for ACL reconstruction in Denmark is the use of an autograft to replace the ruptured ACL. The autograft is harvested from either the m. quadriceps tendon (QT), the m. semitendinosus and m. gracilis tendons (hamstrings) (ST/Gr), or the patella tendon with bone plugs (BPTB).
The BPTB graft was initially used as standard method. It has the advantages of faster graft incorporation (bone to bone healing), reliable graft size and low risk of graft rupture and knee laxity. It is widely used around the world. In Denmark it accounts for app. 10% of all reconstructions. A number of disadvantages of the BPTB graft have been described in the literature: anterior knee pain, pain from the donor site, extension strength deficits, and decreased knee joint flexion range of motion.
Due to these potential morbidity problems of the BPTB graft, there was a shift towards the ST/Gr graft as the preferred choice. Today, the ST/Gr graft is harvested in more than 52% of all ACL reconstructions in Denmark. From a surgeon's perspective, the graft is easy to harvest, time efficient, and leaves smaller scars. The ST/Gr graft is however associated with increased laxity of the knee joint compared to the BPTB graft, and the size of the graft can be a challenge. Also, harvest of the ST/Gr graft is associated with sustained loss of strength, length, and volume of the harvested muscles. This is of concern, as biomechanical research has shown that semitendinosus is essential to stabilize the knee joint and protect the ACL during cutting movements. Finally, recent research indicates higher risk of revision surgery using the ST/Gr graft compared to the BPTB graft.
Currently, particularly in Scandinavia, surgeons are reintroducing a third graft, the QT graft. The advantages of the QT graft are large and predictable graft size and acceptable clinical outcomes. A recent study from the Sports Orthopedic Research Center - Copenhagen (SORC-C) at Hvidovre Hospital found no difference in revision rates between the ST/Gr graft and the QT graft in a cohort of more than 400 patients. The QT graft now accounts for app. 10% of all ACL reconstructions in Denmark, but the graft remains a relatively untested method.
Methods:
Study design and approvals:
This is an assessor-blinded randomized controlled trial with a three-group parallel design. Patients will be randomized to ACL reconstruction with either BPTB, ST/Gr, or QT graft with a 1:1:1 allocation. Follow-up will be performed 1, 6, 12, and 24 months after reconstruction.
The study will adhere to the CONSORT guidelines for reporting of Multi-Arm Parallel-Group Randomized Trials (http://www.consort-statement.org) and is pre-registered at http://www.clinicaltrials.gov.
The study is approved by the Scientific Ethics Committee for the Capital Region (Journal-no.: H-19001194) and by the Danish Data Protection Agency (Jr. no. VD-2018-524)
Randomization and blinding:
Patients will be randomly assigned to a treatment group using a 1:1:1 allocation ratio using a randomization schedule of permuted blocks of random sizes. The randomization will be stratified by biological sex and age. The final randomization will be made after arthroscopic assessment of the knee and evaluation according to the in- and exclusion criteria.
Outcome assessors are blinded to group allocation. Before each patient visit, tape will be placed on possible scars to hide donor graft site. Given the nature of the intervention, blinding of patients and surgeons is not feasible.
Treatment:
The procedure is initiated with knee arthroscopy. Ligament lesions, meniscus tear, and cartilage damage are inspected and treated if indicated, and ACL remnants are removed.
The BPTB graft is harvested through two 4-5 cm incisions, one on the tibial tuberosity and one on the patella. The middle 10 mm of the patella tendon plus 20-30 mm bone plugs at each end from corresponding tibia and patella is harvested.
The ST/Gr graft is harvested through a 4-5 cm incision at the pes anserinus. Both the semitendinosus and the gracilis tendon is identified and harvested. The tendons are prepared and folded to a four-stranded graft with a total diameter of 7-10 mm.
The QT graft is harvested through a 4-5 cm incision at the upper pole of the patella. A graft sized 10-12 mm in with and app. 6 mm in depth is harvested from the middle part of the tendon.
The femoral tunnel is placed anatomically central in the native footprint of the ACL. The tibia tunnel is also placed anatomically; the center of the tunnel being medially between the eminential spines at the level of the posterior margin of the anterior horn of the lateral meniscus. The BPTB graft is fixed both proximally and distally with a Milagro screw (DePuy Synthes) or similar . The ST/Gr and QT grafts are fixed proximally with the RIGIDFIX® Curve Cross Pin System (DePuy Synthes) and distally with a Milagro screw (DePuy Synthes) or similar.
The patients are referred to rehabilitation according to Danish rehabilitation guidelines following ACL reconstruction.
¨
Statistics:
Analysis will be performed with a linear mixed-effects model of the relationships between outcomes and treatment group (BPTB, ST/Gr, and QT graft) and time points (pre-operative, 1-month, 6-month, 12-month, and 24-month follow-up). Fixed effects are time and treatment group, and random effects are patient ID.
Sample size:
The study includes two primary outcomes, the IKDC score change between treatment groups from pre-operative to 12-months follow-up, and the LSI-RFD between treatment groups at 12-months follow-up. The two outcomes are of different hypotheses and independent.
Based on literature, the minimal clinically important difference in IKDC score is approximately 10 points, and the standard deviation on the change in IKDC score from baseline to after ACL reconstruction is approximately 13 points. Based on these assumptions, 37 patients are needed per group (α = 0.05, β = 0.80).
A local unpublished pilot study of 10 healthy individuals showed a minimal detectable difference in LSI-RFD of 12% and a standard deviation in the group of 17%. Based on these assumptions, 40 patients are needed per group (α = 0.05, β = 0.80).
A total inclusion number of 150 is decided to account for a patient dropout of app. 10%.
625 studies on the registry are indexed under Anterior Cruciate Ligament Injuries; 192 are open to participants now.
This study's planned enrollment of 150 is above the median of 56 across 458 interventional studies indexed under Anterior Cruciate Ligament Injuries.
Browse Anterior Cruciate Ligament Injuries studies →Hvidovre University Hospital is the lead sponsor of 299 studies on the registry; 20 are open to participants now.
Counted across the registry records on this site, refreshed daily.
List of Inclusion criteria
List of preoperative exclusion criteria
List of Perioperative exclusion criteria (Arthroscopy)
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Quadriceps tendon autograft (n=50)
Procedure: QT graft
Semitendinosus/gracilis autograft (n=50)
Procedure: ST/Gr graft
Patella tendon autograft (n=50)
Procedure: BPTB graft
Surgical reconstruction of primary ACL rupture with autograft harvested from the quadriceps tendon without bone block. The QT graft is harvested through a 4-5 cm incision at the upper pole of the patella. A graft sized 10-12 mm in with and app. 6 mm in depth is harvested from the middle part of the tendon. The femoral tunnel is placed anatomically central in the native footprint of the ACL. The tibia tunnel is also placed anatomically; the center of the tunnel being medially between the eminential spines at the level of the posterior margin of the anterior horn of the lateral meniscus. The ST/Gr graft is fixed proximally with the RIGIDFIX® Curve Cross Pin System (DePuy Synthes) and distally with a Milagro skrew (DePuy Synthes) or similar.
Surgical reconstruction of primary ACL rupture with autograft harvested from the semitendinosus and gracilis muscles. The ST/Gr graft is harvested through a 4-5 cm incision at the pes anserinus. Both the semitendinosus and the gracilis tendon is identified and harvested. The tendons are prepared and folded to a four-stranded graft with a total diameter of 7-10 mm. The femoral tunnel is placed anatomically central in the native footprint of the ACL. The tibia tunnel is also placed anatomically; the center of the tunnel being medially between the eminential spines at the level of the posterior margin of the anterior horn of the lateral meniscus. The ST/Gr graft is fixed proximally with the RIGIDFIX® Curve Cross Pin System (DePuy Synthes) and distally with a Milagro skrew (DePuy Synthes) or similar.
Surgical reconstruction of primary ACL rupture with autograft harvested from the patella tendon with bone block (bone-patellar-tendon-bone). The BPTB graft is harvested through two 4-5 cm incisions, one on the tibial tuberosity and one on the patella. The middle 10 mm of the patella tendon plus 20-30 mm bone plugs at each end from corresponding tibia and patella is harvested. The femoral tunnel is placed anatomically central in the native footprint of the ACL. The tibia tunnel is also placed anatomically; the center of the tunnel being medially between the eminential spines at the level of the posterior margin of the anterior horn of the lateral meniscus. The BPTB graft is fixed both proximally and distally with a Milagro skrew (DePuy Synthes) or similar.
International Knee Documentation Committee score (IKDC).
Patient-reported knee function based on a questionnaire, expressed on a scale form 0-100 with 100 being the best outcome.
Time frame: 12 months follow up.
Rate of Torque Development - Limb Symmetry Index (RFD-LSI).
Hamstring and quadriceps rate of torque development in the injured/operated leg compared to the healthy leg, expressed in percentage with 100% being full symmetry and the best outcome.
Time frame: 12 months follow up
International Knee Documentation Committee score (IKDC).
Patient-reported knee function based on a questionnaire, expressed on a scale form 0-100 with 100 being the best outcome.
Time frame: Baseline, 1, 6, and 24 months follow up.
Donor site discomfort.
Modified donor-site morbidity score based on the Donor-site-related functional problems questionnaire
Time frame: Baseline, 6, 12, and 24 months follow up.
Return to sport questionnaire.
Patient-reported ability, level, and performance in the sport, they want to return to following ACL reconstruction. The outcome is comparison of the qualitative data obtained in the questionnaires.
Time frame: Baseline, 6, 12 and 24 months follow up.
Workability questionnaire
Patient-reported ability and disadvantages when returning to work following ACL reconstruction. The outcome is comparison of the qualitative data obtained in the questionnaires.
Time frame: Baseline, 1, 6, 12, and 24 months follow up.
Patient Acceptable Symptom State questionnaire (PASS)
A patient-reported questionnaire consisting of one question regarding the patient's overall satisfaction with their knee. The outcome of the questionnaire is binary ("yes" or "no"), and the study's reported outcome is a percentage of patients who meets the threshold for PASS (provides "yes")..
Time frame: Baseline, 12, and 24 months.
Rate of torque Development - Limb Symmetry Index (RFD-LSI).
Hamstring and quadriceps rate of torque development in the injured/operated leg compared to the healthy leg, expressed in percentage with 100% being full symmetry and the best outcome.
Time frame: Baseline, 1, 6, and 24 months follow up.
Knee and hip angles.
Kinematic analysis of knee and hip motion during one-legged dynamic stability exercises (balance, landing, jumping). Outcome is expressed in three-dimensional joint angles (degrees)
Time frame: Baseline, 6, and 12 months follow up.
Knee and hip moments.
Kinetic analysis of knee and hip motion during one-legged dynamic stability exercises (balance, landing, jumping). Outcome is expressed in moments (M)
Time frame: Baseline, 6, and 12 months follow up.
Neuromuscular control.
Muscle activity (EMG) during one-legged dynamic stability exercises (balance, landing, jumping).
Time frame: Baseline, 6, and 12 months follow up.
Knee laxity
Rolimeter measurement (milimeters)
Time frame: Baseline, 6, and 12 months.
Number of patients undergoing revision surgery due to graft failure.
A comparison of the number of patients undergoing revision surgery due to graft failure in each group.
Time frame: Baseline, 12, and 24 months follow up.
Number of patients experiencing re-rupture of the operated ACL.
A comparison of the number of patients experiencing re-rupture to the operated ACL in each group.
Time frame: Baseline, 12, and 24 months follow up.
Muscle cross sectional area
Hamstring and quadriceps cross sectional area expressed in square centimeters based on MRI.
Time frame: At 12 months follow up.
Hamstring muscles retraction
Hamstring muscle length expressed in centimeters based on MRI.
Time frame: At 12 months follow up.
Number of patients experiencing rupture of the contralateral ACL.
A comparison of the number of patients experiencing rupture of the contralateral ACL in each group.
Time frame: Baseline, 12, and 24 months follow up.
Psychological consequences
The Tampa Scale of Kinesiophobia (TSK-11). Score ranges from 11-44, where 11 means no kinesiophobia and is considered the best outcome.
Time frame: 1, 6, 12, and 24 months follow up.
Clinical knee range of motion
Range Of Motion (ROM) of the knee expressed in degrees from full extension to full flexion. -10 to 130 degrees is consideres normal ROM.
Time frame: 6 and 12 months follow up.
One-leg jump performance
Performance in one-legged return to sport jump tests. Outcome expressed in limb symmetry of distance between injured and non-injured leg
Time frame: 6 and 12 months follow up
Postoperative progress
Patient-reported pain and other complications based on questionnaires via SMS-track
Time frame: Every second week through first year following ACL reconstruction.
Postoperative rehabilitation
Patient-reported numbers of hours of supervised and non-supervised rehabilitation via SMS-track
Time frame: Every second week through first year following ACL reconstruction
PDFs hosted by the registry, ClinicalTrials.gov.
Plan to share: Yes — Due to national legislation on anonymisation, no raw data can be available
Supporting information: Study protocol, Statistical analysis plan, Informed consent form
Time frame: 6 months after publication
Access criteria: By request to central contact
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