ACL ReconstructionPhase 4NCT05527548
A Multi-centre, Double-blind RCT to Investigate the Effect of Alendronate on Knee Function Following ACLR
A Phase 4 study testing Alendronate (ALN) in people with ACL Reconstruction, run by Chinese University of Hong Kong at 1 site in Hong Kong.
Trial summary
Anterior cruciate ligament (ACL) is the key ligament connecting the femur to tibia that helps stabilising the knee joint. ACL tear is common. It accounts for over 50% of all knee injuries and affects more than 200,000 people in the United States each year. Read more about this study
- Who is it for?
- Ages 14 years and older
- Conditions the study is for
- ACL Reconstruction
- What is being tested?
- Alendronate (ALN)
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 100 participants
- Where
- 1 siteHong Kong
- Study dates
- 22 Dec 2022to 22 Jul 2028
- Phase
- Phase 4
- 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 14 years and older
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Who may be able to join
- Male and female with age 14 or above at the time of surgery
- First ACLR
- Single leg involvement
- Able to attend pre-operative assessment
- Voluntarily agreed to participate and signed the informed consent form
Who cannot join
- Known chronic disease or receiving long-term medications affecting bone metabolism including BPs
- Contraindication to alendronate therapy such as poor dental fitness
- ACL injury less than 6 weeks
- Injury on duty cases
- Patients who have undergone arthroscopy or open surgery in the index knee in the last 12 months
- Other associated injuries (fractures and other ligament involvement such as neurovascular bundles injury)
Show all 11Show fewer
- Chondral lesion with concomitant intervention
- Presence of X-ray features of osteoarthritis including decrease in joint space, presence of osteophytes and subchondral cysts
- Neurological deficit
- Pregnant or breastfeeding
- Inability to give informed consent
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Hong Kong1 site, 1 recruiting
- Recruiting
Prince of Wales Hospital
Shatin
Pauline LUI, PhD, +852 3505 2730, paulinelui@cuhk.edu.hk
About this study
Official title: The Effect of Oral Administration of Alendronate on Knee Functions Following Anterior Cruciate Ligament Reconstruction - A Multi-Centre, Double-Blind, Placebo-Controlled, Randomized Trial
Anterior cruciate ligament (ACL) is the key ligament connecting the femur to tibia that helps stabilising the knee joint. ACL tear is common. It accounts for over 50% of all knee injuries and affects more than 200,000 people in the United States each year. Patients with ACL tear have a higher risk of developing post-traumatic osteoarthritis. ACL reconstruction (ACLR) with the attachment of tendon grafts within bone tunnels are commonly performed to restore the stability of the joint and thereby minimise injury to both the chondral surface and surrounding tissues. About 130,000 ACLR was performed in the United States in 2006. Both the incidence rates of ACL injuries and ACLR are on the rise, particularly in children and adolescents. Conventional ACLR is not a universally successful procedure, with long healing time and high rates of graft failure (2.8%) and graft laxity (18%). The average cost of an ACLR in the United States was about USD 24,707 ±15,644. The cost for revision surgery and societal cost due to absence from work and sport are expected to be even higher. The demand for a better intervention to improve the outcomes after ACLR and reduce the healing time is huge.
ALN was chosen for the pilot study because it is the most studied BPs, with high bone-binding affinity and more prolonged duration of action. As a member of amino BPs, it also has higher anti-resorptive activities compared to non-amino BPs. Our encouraging results on ALN in the animal studies also provide evidence to support the trial of ALN in human.
Read more
ALN have been shown to have a very good safety and tolerability profile. The common side effects of ALN are stomach pain, constipation, diarrhoea, gas, or nausea. Oral ALN seems can induce mild gastro-intestinal disturbances. However, two studies, with subjects treated with ALN for 10 months and 2.9 years, respectively, showed that ALN was not associated with any increased incidence of upper GI tract events. The serious adverse event, oesophageal cancer, has been associated with ALN. However, two published papers with long term observations of 9 and 4.5 years, respectively, showed that ALN was not significantly associated with incident oesophageal or gastric cancer compared with the control group.
This study aims to evaluate the effects of oral administration of ALN on knee stability (primary), peri-tunnel bone loss, tunnel bone formation, knee laxity, knee muscle strength as well as self-reported knee symptoms, function and sports activity over 12 months in patients undergoing ACLR in a pilot study of single-blind randomised controlled trial.
- Conditions
- ACL Reconstruction
- Being tested
- Alendronate (ALN), Placebo
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Alendronate (ALN)Drug
The oral ALN is the first-line therapy for osteoporosis, and it has been proven that once-weekly ALN 70 mg is an effective and well-tolerated dose for the treatment of postmenopausal osteoporosis. In this study, after receiving the approval of CREC and the Department of Health, we will purchase ALN from drug store. Previous clinical studies have shown that oral administration of ALN at 70mg/week for 1 year and at 5mg/day for 2 years reduced bone loss in postmenopausal women and patients who underwent total hip arthroplasty, respectively. Therefore, in the proposed study, ALN at the dose of 70mg/week will be given to patients post-ACLR for a duration of 8 weeks.
PlaceboDrug
In this study, the placebo is manufactured by a Taiwan factory that follows GMP (Good Manufacturing Practice) regulations. The composition of the placebo has been analyzed by the manufacturer and approved by Central IRB and the Department of Health before starting the study.
| Study group | Role | What they receive |
|---|---|---|
| ALN group | Experimental | Patients receive weekly dose of 70mg of ALN and a standard rehabilitation program Receives: Drug: Alendronate (ALN) |
| PCB Group | Placebo comparator | patients receive weekly dose of placebo and a standard rehabilitation program Receives: Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Single-leg Hop Test (SLH)
SLH test measures the functional stability of the knee with high intraclass correlation coefficients ranging from 0.97 to 0.99 (59). The patient will be asked to perform single-leg hop on both the injured and non-injured legs three times and the hop distance will be recorded. An index score, calculated by dividing the averaged hop distances of the injured leg by that of the non-injured leg, will be reported.
Measured: Change from baseline SLH at 4.5 months
Single-leg Hop Test (SLH)
SLH test measures the functional stability of the knee with high intraclass correlation coefficients ranging from 0.97 to 0.99 (59). The patient will be asked to perform single-leg hop on both the injured and non-injured legs three times and the hop distance will be recorded. An index score, calculated by dividing the averaged hop distances of the injured leg by that of the non-injured leg, will be reported.
Measured: Change from baseline SLH at 6 months
Single-leg Hop Test (SLH)
SLH test measures the functional stability of the knee with high intraclass correlation coefficients ranging from 0.97 to 0.99 (59). The patient will be asked to perform single-leg hop on both the injured and non-injured legs three times and the hop distance will be recorded. An index score, calculated by dividing the averaged hop distances of the injured leg by that of the non-injured leg, will be reported.
Measured: Change from baseline SLH at 12 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Sep 2022
- Study start22 Dec 2022
- Primary completion22 Jul 2028 (estimated)
- Study completion22 Jul 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for ACL ReconstructionStudies of the same condition, open and under way.
- More trials run by Chinese University of Hong KongThe 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 4
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 100 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Chinese University of Hong Kong
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Pauline Lui, Chinese University of Hong Kong
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05527548
- Sponsor's protocol ID
- 2022.346/CIRB-2024-326-5
- Status last verified
- Aug 2026
- First submitted
- 1 Sep 2022
- Last updated
- 12 Aug 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 12 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effect of Oral Administration of Alendronate on Knee Functions Following Anterior Cruciate Ligament Reconstruction - A Multi-Centre, Double-Blind, Placebo-Controlled, Randomized Trial
- ClinicalTrials.gov ID
- NCT05527548
- Acronym / sponsor ID
- 2022.346/CIRB-2024-326-5
- Conditions
- ACL Reconstruction
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 100 participants (estimated)
- Lead sponsor
- Chinese University of Hong KongUniversity, hospital or other
- Study start
- 22 Dec 2022 (actual)
- Primary completion
- 22 Jul 2028 (estimated)
- Study completion
- 22 Jul 2028 (estimated)
- First posted
- 2 Sep 2022 (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.
Anterior cruciate ligament (ACL) is the key ligament connecting the femur to tibia that helps stabilising the knee joint. ACL tear is common. It accounts for over 50% of all knee injuries and affects more than 200,000 people in the United States each year. Patients with ACL tear have a higher risk of developing post-traumatic osteoarthritis. ACL reconstruction (ACLR) with the attachment of tendon grafts within bone tunnels are commonly performed to restore the stability of the joint and thereby minimise injury to both the chondral surface and surrounding tissues. About 130,000 ACLR was performed in the United States in 2006. Both the incidence rates of ACL injuries and ACLR are on the rise, particularly in children and adolescents. Conventional ACLR is not a universally successful procedure, with long healing time and high rates of graft failure (2.8%) and graft laxity (18%). The average cost of an ACLR in the United States was about USD 24,707 ±15,644. The cost for revision surgery and societal cost due to absence from work and sport are expected to be even higher. The demand for a better intervention to improve the outcomes after ACLR and reduce the healing time is huge.
ALN was chosen for the pilot study because it is the most studied BPs, with high bone-binding affinity and more prolonged duration of action. As a member of amino BPs, it also has higher anti-resorptive activities compared to non-amino BPs. Our encouraging results on ALN in the animal studies also provide evidence to support the trial of ALN in human.
ALN have been shown to have a very good safety and tolerability profile. The common side effects of ALN are stomach pain, constipation, diarrhoea, gas, or nausea. Oral ALN seems can induce mild gastro-intestinal disturbances. However, two studies, with subjects treated with ALN for 10 months and 2.9 years, respectively, showed that ALN was not associated with any increased incidence of upper GI tract events. The serious adverse event, oesophageal cancer, has been associated with ALN. However, two published papers with long term observations of 9 and 4.5 years, respectively, showed that ALN was not significantly associated with incident oesophageal or gastric cancer compared with the control group.
This study aims to evaluate the effects of oral administration of ALN on knee stability (primary), peri-tunnel bone loss, tunnel bone formation, knee laxity, knee muscle strength as well as self-reported knee symptoms, function and sports activity over 12 months in patients undergoing ACLR in a pilot study of single-blind randomised controlled trial.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| ALN group | Experimental | Drug: Alendronate (ALN)Patients receive weekly dose of 70mg of ALN and a standard rehabilitation program |
| PCB Group | Placebo comparator | Drug: Placebopatients receive weekly dose of placebo and a standard rehabilitation program |
Who may qualify
- Ages
- 14 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (5 listed)
- Male and female with age 14 or above at the time of surgery
- First ACLR
- Single leg involvement
- Able to attend pre-operative assessment
- Voluntarily agreed to participate and signed the informed consent form
Key exclusion criteria (11 listed)
- Known chronic disease or receiving long-term medications affecting bone metabolism including BPs
- Contraindication to alendronate therapy such as poor dental fitness
- ACL injury less than 6 weeks
- Injury on duty cases
- Patients who have undergone arthroscopy or open surgery in the index knee in the last 12 months
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 |
|---|---|---|
| Alendronate (ALN)The oral ALN is the first-line therapy for osteoporosis, and it has been proven that once-weekly ALN 70 mg is an effective and well-tolerated dose for the treatment of postmenopausal osteoporosis. In this study, after receiving the approval of CREC and the Department of Health, we will purchase ALN from drug store. Previous clinical studies have shown that oral administration of ALN at 70mg/week for 1 year and at 5mg/day for 2 years reduced bone loss in postmenopausal women and patients who underwent total hip arthroplasty, respectively. Therefore, in the proposed study, ALN at the dose of 70mg/week will be given to patients post-ACLR for a duration of 8 weeks. | Drug | ALN group |
| PlaceboIn this study, the placebo is manufactured by a Taiwan factory that follows GMP (Good Manufacturing Practice) regulations. The composition of the placebo has been analyzed by the manufacturer and approved by Central IRB and the Department of Health before starting the study. | Drug | PCB Group |
Primary outcome
Single-leg Hop Test (SLH)
Time frame: Change from baseline SLH at 4.5 months
SLH test measures the functional stability of the knee with high intraclass correlation coefficients ranging from 0.97 to 0.99 (59). The patient will be asked to perform single-leg hop on both the injured and non-injured legs three times and the hop distance will be recorded. An index score, calculated by dividing the averaged hop distances of the injured leg by that of the non-injured leg, will be reported.
Single-leg Hop Test (SLH)
Time frame: Change from baseline SLH at 6 months
SLH test measures the functional stability of the knee with high intraclass correlation coefficients ranging from 0.97 to 0.99 (59). The patient will be asked to perform single-leg hop on both the injured and non-injured legs three times and the hop distance will be recorded. An index score, calculated by dividing the averaged hop distances of the injured leg by that of the non-injured leg, will be reported.
Single-leg Hop Test (SLH)
Time frame: Change from baseline SLH at 12 months
SLH test measures the functional stability of the knee with high intraclass correlation coefficients ranging from 0.97 to 0.99 (59). The patient will be asked to perform single-leg hop on both the injured and non-injured legs three times and the hop distance will be recorded. An index score, calculated by dividing the averaged hop distances of the injured leg by that of the non-injured leg, will be reported.
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 12 Aug 2026.
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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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing Alendronate (ALN) in people with ACL Reconstruction, run by Chinese University of Hong Kong at 1 site in Hong Kong.
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 5 inclusion and 11 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: looking for participants now, as of the sponsor's last update on 12 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Hong Kong. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
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?
Contact Patrick Shu-hang YUNG (+852 3505 2728, patrickyung@cuhk.edu.hk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Single-leg Hop Test (SLH) (time frame: Change from baseline SLH at 4.5 months). The study lists 3 primary outcomes in all. 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 12 Aug 2026; AzTrials last refreshed its copy on 1 Nov 2026.