Anterior Cruciate Ligament TearNCT06891430
Prognosis Analysis of Three Surgical Techniques for Arthroscopic Anterior Cruciate Ligament Reconstruction
A study testing Procedure: Anatomical Single-Bundle ACL Reconstruction, Procedure: Central Axial Single-Bundle ACL Reconstruction and Procedure: Double-Bundle ACL Reconstruction in people with Anterior Cruciate Ligament Tear, run by Beijing Tsinghua Chang Gung Hospital.
Trial summary
This study hypothesizes that the tunnel positioning and drilling direction in two single-bundle reconstruction techniques (Anatomical Single-Bundle Reconstruction, ASBR, and Central Axial Single-Bundle Reconstruction, CASBR) influence the biomechanical environment of the graft, thereby affecting graft remodeling and… Read more about this study
- Who is it for?
- Ages 18 to 50 years
- Conditions the study is for
- Anterior Cruciate Ligament Tear
- What is being tested?
- Procedure: Anatomical Single-Bundle ACL Reconstruction, Procedure: Central Axial Single-Bundle ACL Reconstruction and Procedure: Double-Bundle ACL Reconstruction
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 180 participants
- Where
- No sites listed yet
- Study dates
- 1 Apr 2025to 1 Jun 2025
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 50 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- Diagnosed with anterior cruciate ligament (ACL) rupture; Age between 18-50 years; All patients must have isolated anterior cruciate ligament (ACL) rupture; Knee joint degeneration < KL grade II, and intraoperative cartilage injury < ICRS grade III; All isolated ACL rupture patients must not have other ligament injuries; If accompanied by meniscus injury, the proportion of medial or lateral meniscus resection during surgery must not exceed 40%; The duration of the condition must be within one year after injury; No restriction on body weight; The cause of ACL rupture must be sports-related trauma or twisting injuries, excluding car accident injuries.
Who cannot join
- Patients with other surgical contraindications; Patients with poor compliance; Patients planning pregnancy; Patients deemed unsuitable for inclusion by the researchers.
About this study
This study hypothesizes that the tunnel positioning and drilling direction in two single-bundle reconstruction techniques (Anatomical Single-Bundle Reconstruction, ASBR, and Central Axial Single-Bundle Reconstruction, CASBR) influence the biomechanical environment of the graft, thereby affecting graft remodeling and maturation, ultimately impacting postoperative outcomes. Studies have shown that the graft bending angle (GBA) is a critical factor affecting graft ligamentization. ASBR, with a higher GBA, may result in poorer graft maturation, while CASBR, with a lower GBA, may provide a more favorable biomechanical environment. Additionally, graft volume has been identified as an important factor influencing postoperative graft maturation. Therefore, this study also examines the double-bundle reconstruction (DBR) technique, which has a GBA similar to CASBR.
The Impact of Three Techniques on Graft Maturation Anatomical Single-Bundle Reconstruction (ASBR)
Read more
ASBR involves drilling a single tunnel at both the femoral and tibial ends, with the tunnel positioned at the center of the dense fiber area of the ACL footprint. The femoral tunnel is positioned at 90° knee flexion and drilled at 120°, while the tibial tunnel is positioned at 70° knee flexion. Due to the higher GBA in ASBR, the graft may experience greater bending stress during motion, leading to impaired graft maturation, limited ligamentization, and increased stress concentration around the tunnel, potentially causing tunnel widening.
Central Axial Single-Bundle Reconstruction (CASBR)
CASBR also involves drilling a single tunnel at both ends, but the tunnel is positioned in the posterior region of the dense fiber area of the ACL footprint, mimicking the central axis of the native ACL. The femoral tunnel is positioned at 90° knee flexion and drilled at 120°, while the tibial tunnel is positioned at 70° knee flexion. Compared to ASBR, CASBR's lower GBA results in more uniform graft stress distribution, promoting better graft maturation and reducing the risk of stress concentration and tunnel widening.
Double-Bundle Reconstruction (DBR)
DBR involves drilling two tunnels at both the femoral and tibial ends, targeting the dense fiber areas of the anterior medial bundle (AMB) and posterior lateral bundle (PLB) of the ACL footprint. The positioning of the PLB tunnel is similar to CASBR, while the AMB tunnel is located in the anterior region of the footprint. DBR provides a more anatomically accurate distribution of forces, leading to a more even biomechanical environment. However, the increased number of tunnels may complicate stress distribution.
Impact on Postoperative Outcomes ASBR, with its higher GBA, may lead to poor graft maturation and increased tunnel widening. CASBR, with a lower GBA, offers a more favorable biomechanical environment for graft maturation. While DBR ensures a more uniform force distribution, the additional tunnels may introduce complexities in stress distribution, potentially affecting postoperative recovery and return to sports (RTS).
Read the detailed description
Hypothesis and Background This study hypothesizes that the tunnel positioning and drilling direction of two single-bundle reconstruction techniques influence the biomechanical environment of the graft, which may affect graft remodeling. Poor biomechanical environments could result in suboptimal graft maturation and worse return-to-sport (RTS) outcomes. Previous research has identified the graft bending angle (GBA) as a risk factor for graft ligamentization. Anatomical Single-Bundle Reconstruction (ASBR) is associated with a higher GBA, whereas Central Axial Single-Bundle Reconstruction (CASBR) has a relatively lower GBA. Recent studies have also highlighted the influence of graft volume on postoperative graft maturation. Therefore, this section further discusses ACL double-bundle reconstruction (DBR), which has a GBA similar to CASBR. The anatomical and directional terminologies used in this study are based on the ESSKA scientific seminar on ACL reconstruction held at Imperial College London.
Techniques Anatomical Single-Bundle Reconstruction (ASBR)
ASBR involves drilling single femoral and tibial tunnels, both positioned at the center of the dense fiber area of the native ACL footprint. This technique represents the anatomical location of the ACL.
Femoral Tunnel: Positioned arthroscopically through the anteromedial portal at 90° knee flexion, targeting the center of the ACL femoral footprint. A guidewire is used without a positioning device, and the femoral tunnel is drilled at 120° knee flexion.
Tibial Tunnel: Positioned arthroscopically through the anteromedial portal at 70° knee flexion using the Smith \& Nephew tibial tunnel guide. The tibial tunnel is drilled at the center of the ACL tibial footprint, with angles adjusted to 55° relative to the horizontal plane and 30° medially from the sagittal plane.
Central Axial Single-Bundle Reconstruction (CASBR)
CASBR also involves single femoral and tibial tunnels, but the tunnel positions mimic the central axis of the native ACL, spanning the dense fiber structure from anteromedial to posterolateral.
Femoral Tunnel: Positioned arthroscopically at 90° knee flexion through the anteromedial portal, targeting the posterior 60% of the ACL femoral footprint. The tunnel is drilled at 120° knee flexion.
Tibial Tunnel: Positioned arthroscopically at 70° knee flexion through the anteromedial portal using the Smith \& Nephew tibial tunnel guide. The tunnel is drilled at the posterior 40% of the ACL tibial footprint, with angles adjusted to 50° relative to the sagittal plane and 40° medially from the tibial tubercle sagittal plane.
Double-Bundle Reconstruction (DBR)
DBR involves drilling two tunnels at both the femoral and tibial sides to reconstruct the anterior medial bundle (AMB) and posterior lateral bundle (PLB) of the ACL.
PLB Tunnels: The femoral tunnel is positioned at the anterior 40% of the ACL femoral footprint at 90° knee flexion and drilled at 120°. The tibial tunnel follows the CASBR tibial tunnel positioning.
AMB Tunnels: The femoral tunnel follows CASBR positioning, while the tibial tunnel is positioned at the anterior 60% of the ACL tibial footprint at 65° relative to the horizontal plane and 40° medially from the tibial tubercle sagittal plane.
Biomechanical Differences and Graft Maturation Biomechanical variations among these techniques significantly influence graft maturation and tunnel widening.
ASBR: The higher GBA results in increased bending stress on the graft, potentially impairing graft maturation and ligamentization. This stress may also lead to higher stress concentrations around the tunnel, increasing the risk of tunnel widening.
CASBR: The lower GBA provides a more favorable biomechanical environment with more uniform stress distribution. This reduces stress concentrations and minimizes the risk of tunnel widening, promoting better graft maturation.
DBR: While DBR offers a more anatomically accurate force distribution, the additional tunnels may complicate stress distribution and pose a risk of stress concentration, particularly at the bone bridges between the tunnels.
Postoperative Rehabilitation Protocol
All three surgical techniques followed the same standardized postoperative rehabilitation protocol, which has been consistently used in our institution to ensure uniformity across patient groups. The protocol includes the following components:
Knee Flexion: Patients begin knee flexion exercises on postoperative day 5, reaching 90° initially. Flexion angles are increased every two days, with a goal of 120° by six weeks and full flexion by three months.
Weight-Bearing: No weight-bearing is allowed for the first six weeks. Full weight-bearing walking is permitted after six weeks, but walking distances are minimized until three months.
Bracing: A knee brace is immediately applied postoperatively at 0° flexion. The brace is worn continuously for six weeks, except during flexion exercises. After six weeks, braces are only required outdoors, and no bracing is needed after three months.
Physical Activity: Normal walking is allowed within four months, but distances are limited. Running is restricted to 50 meters of slow jogging until six months postoperatively. High-impact sports are only permitted after nine months, provided that quadriceps strength reaches at least 80% of the contralateral side, hamstring-to-quadriceps strength ratio exceeds 85%, proprioception training is completed, and the patient undergoes sport-specific adaptation exercises for 2-3 months.
Conclusion The consistent use of this rehabilitation protocol ensures comparability across surgical techniques and minimizes variability in recovery. However, the biomechanical differences among ASBR, CASBR, and DBR highlight their distinct effects on graft maturation and tunnel widening. CASBR, with its more favorable biomechanical environment, appears to offer the best balance between graft maturation and minimal tunnel widening, while ASBR and DBR may require careful consideration of their respective biomechanical challenges.
- Conditions
- Anterior Cruciate Ligament Tear
- Being tested
- Procedure: Anatomical Single-Bundle ACL Reconstruction, Procedure: Central Axial Single-Bundle ACL Reconstruction, Procedure: Double-Bundle ACL Reconstruction
- Keywords
- tunnel widening, Anterior Cruciate Ligament, double-bundle reconstruction, single-bundle reconstruction
- Medical subject headings
- Anterior Cruciate Ligament Injuries
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Procedure: Anatomical Single-Bundle ACL ReconstructionProcedure or surgery
Patients undergo anatomical single-bundle ACL reconstruction with femoral and tibial tunnel drilling.
Procedure: Central Axial Single-Bundle ACL ReconstructionProcedure or surgery
Patients undergo central axial single-bundle ACL reconstruction with optimized tunnel positioning.
Procedure: Double-Bundle ACL ReconstructionProcedure or surgery
Patients undergo double-bundle ACL reconstruction targeting AMB and PLB footprints.
| Study group | Role | What they receive |
|---|---|---|
| ASBR Group | Experimental | Description: Patients in this group will undergo anatomical single-bundle ACL reconstruction (ASBR). The femoral and tibial tunnels will be positioned at the center of the dense fiber area of the native ACL footprint. Graft fixation will be performed using EndoButton on the femoral side and bioabsorbable screws on the tibial side. Receives: Procedure: Procedure: Anatomical Single-Bundle ACL Reconstruction |
| CASBR Group | Experimental | Description: Patients in this group will undergo central axial single-bundle ACL reconstruction (CASBR). The femoral and tibial tunnels will mimic the central axis of the native ACL, spanning the dense fiber structure from anteromedial to posterolateral. Graft fixation will follow the same protocol as the ASBR group. Receives: Procedure: Procedure: Central Axial Single-Bundle ACL Reconstruction |
| DBR Group | Experimental | Description: Patients in this group will undergo ACL double-bundle reconstruction (DBR), with separate femoral and tibial tunnels for the anterior medial bundle (AMB) and posterior lateral bundle (PLB). Graft fixation will involve independent tensioning of AMB and PLB grafts at different knee flexion angles. Receives: Procedure: Procedure: Double-Bundle ACL Reconstruction |
What is being measured
The primary outcome is the main question the study is designed to answer.
tunnel widening
Tunnel widening is measured as the percentage change in cross-sectional area of the graft tunnel. Using CT and MRI, we measure the cross-sectional area perpendicular to the graft tunnel two days after surgery (baseline) and again during follow-up. The tunnel enlargement rate is calculated as:
Tunnel Enlargement Rate = (Follow-up Tunnel Area - Postoperative Day 2 Tunnel Area) / Postoperative Day 2 Tunnel Area × 100%
The measurement unit is percentage (%), with higher percentages indicating greater tunnel widening.
Measured: From two days postoperatively to two years postoperatively
Secondary outcomes (4)
Return to sport
The Return to Sport (RTS) Safety Assessment evaluates functional recovery following ACL reconstruction through comprehensive testing of muscle strength and functional performance.
Testing includes:
Isokinetic quadriceps strength tests at 60°/s using an electromechanical dynamometer (Biodex System III dynamometer, Biodex Medical Systems) Four types of single-legged hop tests Each participant receives a demonstration and two practice sessions prior to the formal tests, which occur 20 minutes post-exercise. All tests are performed on both the injured and uninjured legs.
The measurement unit is the Leg Symmetry Index (LSI), calculated as a percentage (%) by comparing the performance of the injured leg to the uninjured leg. The final score is recorded as the mean LSI% across both the hop and isokinetic tests. An LSI of 100% indicates perfect symmetry between legs, with higher percentages representing better functional recovery.
Measured: Follow-up more than two years postoperatively.
IKDC 2000
The IKDC 2000 Subjective Knee Evaluation is a patient-reported outcome measure that assesses symptoms, sports activities, and function. The preoperative score is measured as baseline data for comparability, and the follow-up score after more than two years postoperatively is used to compare clinical outcomes among the three surgical techniques.
The measurement unit is a standardized score ranging from 0 to 100, where 0 represents the lowest level of function and highest level of symptoms, and 100 represents the highest level of function and lowest level of symptoms.
Measured: Recorded preoperatively and at follow-up more than two years postoperatively.
Lyholm score
The Lysholm Knee Scoring Scale evaluates knee function in activities of daily living. The preoperative score is measured as baseline data for comparability, and the follow-up score after more than two years postoperatively is used to compare clinical outcomes among the three surgical techniques.
The measurement unit is a numerical score ranging from 0 to 100, where 0 represents severe knee problems and 100 represents normal knee function.
Measured: Recorded preoperatively and at follow-up more than two years postoperatively.
Tegner
The Tegner Activity Scale assesses activity level specifically related to knee function. The preoperative score is measured as baseline data for comparability, and the follow-up score after more than two years postoperatively is used to compare functional recovery among the three surgical techniques.
The measurement unit is a numerical score ranging from 0 to 10, where 0 represents disability due to knee problems and 10 represents participation in competitive sports at a national or international elite level.
Measured: From two days postoperatively to two years postoperatively
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Mar 2025
- Study start1 Apr 2025 (estimated)
- Primary completion1 May 2025 (estimated)
- Study completion1 Jun 2025 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Anterior Cruciate Ligament TearStudies of the same condition, open and under way.
- More trials run by Beijing Tsinghua Chang Gung HospitalThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 180 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Beijing Tsinghua Chang Gung Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06891430
- Sponsor's protocol ID
- 24765-4-01
- Status last verified
- Mar 2025
- First submitted
- 11 Mar 2025
- Last updated
- 24 Mar 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided: The decision not to share clinical trial results publicly is primarily driven by the need to protect patient privacy and comply with ethical and legal standards. Even with anonymization, there is a potential risk of re-identification, especially in studies involving small or unique populations. Additionally, unpublished results may involve incomplete data, ongoing analyses, or findings that require further validation to ensure accuracy and reliability. Sharing such data prematurely could lead to misinterpretation or misuse. Therefore, withholding results in certain cases is a precaution to safeguard patient confidentiality and maintain the scientific integrity of the research.
Study at a glance
From the registry record, last updated by the sponsor on 24 Mar 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Prognosis Analysis of Three Surgical Techniques for Arthroscopic Anterior Cruciate Ligament Reconstruction
- ClinicalTrials.gov ID
- NCT06891430
- Acronym / sponsor ID
- 24765-4-01
- Conditions
- Anterior Cruciate Ligament Tear
- Keywords
- tunnel widening, Anterior Cruciate Ligament, double-bundle reconstruction, single-bundle reconstruction
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 180 participants (estimated)
- Lead sponsor
- Beijing Tsinghua Chang Gung HospitalUniversity, hospital or other
- Study start
- 1 Apr 2025 (estimated)
- Primary completion
- 1 May 2025 (estimated)
- Study completion
- 1 Jun 2025 (estimated)
- First posted
- 24 Mar 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study hypothesizes that the tunnel positioning and drilling direction in two single-bundle reconstruction techniques (Anatomical Single-Bundle Reconstruction, ASBR, and Central Axial Single-Bundle Reconstruction, CASBR) influence the biomechanical environment of the graft, thereby affecting graft remodeling and maturation, ultimately impacting postoperative outcomes. Studies have shown that the graft bending angle (GBA) is a critical factor affecting graft ligamentization. ASBR, with a higher GBA, may result in poorer graft maturation, while CASBR, with a lower GBA, may provide a more favorable biomechanical environment. Additionally, graft volume has been identified as an important factor influencing postoperative graft maturation. Therefore, this study also examines the double-bundle reconstruction (DBR) technique, which has a GBA similar to CASBR.
The Impact of Three Techniques on Graft Maturation Anatomical Single-Bundle Reconstruction (ASBR)
ASBR involves drilling a single tunnel at both the femoral and tibial ends, with the tunnel positioned at the center of the dense fiber area of the ACL footprint. The femoral tunnel is positioned at 90° knee flexion and drilled at 120°, while the tibial tunnel is positioned at 70° knee flexion. Due to the higher GBA in ASBR, the graft may experience greater bending stress during motion, leading to impaired graft maturation, limited ligamentization, and increased stress concentration around the tunnel, potentially causing tunnel widening.
Central Axial Single-Bundle Reconstruction (CASBR)
CASBR also involves drilling a single tunnel at both ends, but the tunnel is positioned in the posterior region of the dense fiber area of the ACL footprint, mimicking the central axis of the native ACL. The femoral tunnel is positioned at 90° knee flexion and drilled at 120°, while the tibial tunnel is positioned at 70° knee flexion. Compared to ASBR, CASBR's lower GBA results in more uniform graft stress distribution, promoting better graft maturation and reducing the risk of stress concentration and tunnel widening.
Double-Bundle Reconstruction (DBR)
DBR involves drilling two tunnels at both the femoral and tibial ends, targeting the dense fiber areas of the anterior medial bundle (AMB) and posterior lateral bundle (PLB) of the ACL footprint. The positioning of the PLB tunnel is similar to CASBR, while the AMB tunnel is located in the anterior region of the footprint. DBR provides a more anatomically accurate distribution of forces, leading to a more even biomechanical environment. However, the increased number of tunnels may complicate stress distribution.
Impact on Postoperative Outcomes ASBR, with its higher GBA, may lead to poor graft maturation and increased tunnel widening. CASBR, with a lower GBA, offers a more favorable biomechanical environment for graft maturation. While DBR ensures a more uniform force distribution, the additional tunnels may introduce complexities in stress distribution, potentially affecting postoperative recovery and return to sports (RTS).
Detailed description
Hypothesis and Background This study hypothesizes that the tunnel positioning and drilling direction of two single-bundle reconstruction techniques influence the biomechanical environment of the graft, which may affect graft remodeling. Poor biomechanical environments could result in suboptimal graft maturation and worse return-to-sport (RTS) outcomes. Previous research has identified the graft bending angle (GBA) as a risk factor for graft ligamentization. Anatomical Single-Bundle Reconstruction (ASBR) is associated with a higher GBA, whereas Central Axial Single-Bundle Reconstruction (CASBR) has a relatively lower GBA. Recent studies have also highlighted the influence of graft volume on postoperative graft maturation. Therefore, this section further discusses ACL double-bundle reconstruction (DBR), which has a GBA similar to CASBR. The anatomical and directional terminologies used in this study are based on the ESSKA scientific seminar on ACL reconstruction held at Imperial College London.
Techniques Anatomical Single-Bundle Reconstruction (ASBR)
ASBR involves drilling single femoral and tibial tunnels, both positioned at the center of the dense fiber area of the native ACL footprint. This technique represents the anatomical location of the ACL.
Femoral Tunnel: Positioned arthroscopically through the anteromedial portal at 90° knee flexion, targeting the center of the ACL femoral footprint. A guidewire is used without a positioning device, and the femoral tunnel is drilled at 120° knee flexion.
Tibial Tunnel: Positioned arthroscopically through the anteromedial portal at 70° knee flexion using the Smith \& Nephew tibial tunnel guide. The tibial tunnel is drilled at the center of the ACL tibial footprint, with angles adjusted to 55° relative to the horizontal plane and 30° medially from the sagittal plane.
Central Axial Single-Bundle Reconstruction (CASBR)
CASBR also involves single femoral and tibial tunnels, but the tunnel positions mimic the central axis of the native ACL, spanning the dense fiber structure from anteromedial to posterolateral.
Femoral Tunnel: Positioned arthroscopically at 90° knee flexion through the anteromedial portal, targeting the posterior 60% of the ACL femoral footprint. The tunnel is drilled at 120° knee flexion.
Tibial Tunnel: Positioned arthroscopically at 70° knee flexion through the anteromedial portal using the Smith \& Nephew tibial tunnel guide. The tunnel is drilled at the posterior 40% of the ACL tibial footprint, with angles adjusted to 50° relative to the sagittal plane and 40° medially from the tibial tubercle sagittal plane.
Double-Bundle Reconstruction (DBR)
DBR involves drilling two tunnels at both the femoral and tibial sides to reconstruct the anterior medial bundle (AMB) and posterior lateral bundle (PLB) of the ACL.
PLB Tunnels: The femoral tunnel is positioned at the anterior 40% of the ACL femoral footprint at 90° knee flexion and drilled at 120°. The tibial tunnel follows the CASBR tibial tunnel positioning.
AMB Tunnels: The femoral tunnel follows CASBR positioning, while the tibial tunnel is positioned at the anterior 60% of the ACL tibial footprint at 65° relative to the horizontal plane and 40° medially from the tibial tubercle sagittal plane.
Biomechanical Differences and Graft Maturation Biomechanical variations among these techniques significantly influence graft maturation and tunnel widening.
ASBR: The higher GBA results in increased bending stress on the graft, potentially impairing graft maturation and ligamentization. This stress may also lead to higher stress concentrations around the tunnel, increasing the risk of tunnel widening.
CASBR: The lower GBA provides a more favorable biomechanical environment with more uniform stress distribution. This reduces stress concentrations and minimizes the risk of tunnel widening, promoting better graft maturation.
DBR: While DBR offers a more anatomically accurate force distribution, the additional tunnels may complicate stress distribution and pose a risk of stress concentration, particularly at the bone bridges between the tunnels.
Postoperative Rehabilitation Protocol
All three surgical techniques followed the same standardized postoperative rehabilitation protocol, which has been consistently used in our institution to ensure uniformity across patient groups. The protocol includes the following components:
Knee Flexion: Patients begin knee flexion exercises on postoperative day 5, reaching 90° initially. Flexion angles are increased every two days, with a goal of 120° by six weeks and full flexion by three months.
Weight-Bearing: No weight-bearing is allowed for the first six weeks. Full weight-bearing walking is permitted after six weeks, but walking distances are minimized until three months.
Bracing: A knee brace is immediately applied postoperatively at 0° flexion. The brace is worn continuously for six weeks, except during flexion exercises. After six weeks, braces are only required outdoors, and no bracing is needed after three months.
Physical Activity: Normal walking is allowed within four months, but distances are limited. Running is restricted to 50 meters of slow jogging until six months postoperatively. High-impact sports are only permitted after nine months, provided that quadriceps strength reaches at least 80% of the contralateral side, hamstring-to-quadriceps strength ratio exceeds 85%, proprioception training is completed, and the patient undergoes sport-specific adaptation exercises for 2-3 months.
Conclusion The consistent use of this rehabilitation protocol ensures comparability across surgical techniques and minimizes variability in recovery. However, the biomechanical differences among ASBR, CASBR, and DBR highlight their distinct effects on graft maturation and tunnel widening. CASBR, with its more favorable biomechanical environment, appears to offer the best balance between graft maturation and minimal tunnel widening, while ASBR and DBR may require careful consideration of their respective biomechanical challenges.
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| ASBR Group | Experimental | Procedure: Procedure: Anatomical Single-Bundle ACL ReconstructionDescription: Patients in this group will undergo anatomical single-bundle ACL reconstruction (ASBR). The femoral and tibial tunnels will be positioned at the center of the dense fiber area of the native ACL footprint. Graft fixation will be performed using EndoButton on the femoral side and bioabsorbable screws on the tibial side. |
| CASBR Group | Experimental | Procedure: Procedure: Central Axial Single-Bundle ACL ReconstructionDescription: Patients in this group will undergo central axial single-bundle ACL reconstruction (CASBR). The femoral and tibial tunnels will mimic the central axis of the native ACL, spanning the dense fiber structure from anteromedial to posterolateral. Graft fixation will follow the same protocol as the ASBR group. |
| DBR Group | Experimental | Procedure: Procedure: Double-Bundle ACL ReconstructionDescription: Patients in this group will undergo ACL double-bundle reconstruction (DBR), with separate femoral and tibial tunnels for the anterior medial bundle (AMB) and posterior lateral bundle (PLB). Graft fixation will involve independent tensioning of AMB and PLB grafts at different knee flexion angles. |
Who may qualify
- Ages
- 18 to 50 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (1 listed)
- Diagnosed with anterior cruciate ligament (ACL) rupture; Age between 18-50 years; All patients must have isolated anterior cruciate ligament (ACL) rupture; Knee joint degeneration < KL grade II, and intraoperative cartilage injury < ICRS grade III; All isolated ACL rupture patients must not have other ligament injuries; If accompanied by meniscus injury, the proportion of medial or lateral meniscus resection during surgery must not exceed 40%; The duration of the condition must be within one year after injury; No restriction on body weight; The cause of ACL rupture must be sports-related trauma or twisting injuries, excluding car accident injuries.
Key exclusion criteria (1 listed)
- Patients with other surgical contraindications; Patients with poor compliance; Patients planning pregnancy; Patients deemed unsuitable for inclusion by the researchers.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Procedure: Anatomical Single-Bundle ACL ReconstructionPatients undergo anatomical single-bundle ACL reconstruction with femoral and tibial tunnel drilling. | Procedure or surgery | ASBR Group |
| Procedure: Central Axial Single-Bundle ACL ReconstructionPatients undergo central axial single-bundle ACL reconstruction with optimized tunnel positioning. | Procedure or surgery | CASBR Group |
| Procedure: Double-Bundle ACL ReconstructionPatients undergo double-bundle ACL reconstruction targeting AMB and PLB footprints. | Procedure or surgery | DBR Group |
Primary outcome
tunnel widening
Time frame: From two days postoperatively to two years postoperatively
Tunnel widening is measured as the percentage change in cross-sectional area of the graft tunnel. Using CT and MRI, we measure the cross-sectional area perpendicular to the graft tunnel two days after surgery (baseline) and again during follow-up. The tunnel enlargement rate is calculated as: Tunnel Enlargement Rate = (Follow-up Tunnel Area - Postoperative Day 2 Tunnel Area) / Postoperative Day 2 Tunnel Area × 100% The measurement unit is percentage (%), with higher percentages indicating greater tunnel widening.
4 secondary outcomes
Return to sport
Time frame: Follow-up more than two years postoperatively.
IKDC 2000
Time frame: Recorded preoperatively and at follow-up more than two years postoperatively.
Lyholm score
Time frame: Recorded preoperatively and at follow-up more than two years postoperatively.
Tegner
Time frame: From two days postoperatively to two years postoperatively
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 24 Mar 2025.
- Individual participant dataSharing planned: Undecided. The decision not to share clinical trial results publicly is primarily driven by the need to protect patient privacy and comply with ethical and legal standards. Even with anonymization, there is a potential risk of re-identification, especially in studies involving small or unique populations. Additionally, unpublished results may involve incomplete data, ongoing analyses, or findings that require further validation to ensure accuracy and reliability. Sharing such data prematurely could lead to misinterpretation or misuse. Therefore, withholding results in certain cases is a precaution to safeguard patient confidentiality and maintain the scientific integrity of the research.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
The record lists no contact. Use the official record to reach the sponsor.
Questions about this trial
What is this clinical trial studying?
A study testing Procedure: Anatomical Single-Bundle ACL Reconstruction, Procedure: Central Axial Single-Bundle ACL Reconstruction and Procedure: Double-Bundle ACL Reconstruction in people with Anterior Cruciate Ligament Tear, run by Beijing Tsinghua Chang Gung Hospital.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 24 Mar 2025. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
tunnel widening (time frame: From two days postoperatively to two years postoperatively). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 24 Mar 2025.