Botulinum toxin treatment for hamstring contractures after ACL surgery

Effect of Botulinum Toxin on Hamstring Contracture and the Occurrence of Cyclops Syndrome After Anterior Cruciate Ligament Reconstruction

PHASE3 · GCS Ramsay Santé pour l'Enseignement et la Recherche · NCT05008731

This study is testing if botulinum toxin injections can help people who have tight hamstrings after ACL surgery improve their knee movement.

Quick facts

PhasePHASE3
Study typeInterventional
Enrollment132 (estimated)
Ages18 Years and up
SexAll
SponsorGCS Ramsay Santé pour l'Enseignement et la Recherche (other)
Locations1 site (Paris)
Trial IDNCT05008731 on ClinicalTrials.gov

What this trial studies

This clinical trial investigates the effectiveness of botulinum toxin injections in treating hamstring contractures that may occur after anterior cruciate ligament (ACL) reconstruction. It is a monocentric, prospective, randomized, double-blind study involving two groups of 66 patients, where one group receives botulinum toxin and the other a placebo. The patients will be assessed at one month, two months, and five months post-surgery to evaluate the improvement in knee extension. The primary outcome measure is the change in extension defect at two months after treatment.

Who should consider this trial

Good fit: Ideal candidates are adults over 18 who have undergone primary ACL ligamentoplasty and have a reducible extension deficit greater than 10 degrees one month post-surgery.

Not a fit: Patients who have had revision ligamentoplasty, multi-ligament knee injuries, or those with contraindications to botulinum toxin will not benefit from this study.

Why it matters

Potential benefit: If successful, this treatment could significantly improve knee function and reduce complications associated with hamstring contractures after ACL reconstruction.

How similar studies have performed: While the use of botulinum toxin for muscle contractures is established, this specific application in post-ACL reconstruction is novel and has not been extensively tested in prior studies.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Patient over 18 years of age
* Patient who has read and signed the consent form for participation in the study
* Patient operated on for primary ACL ligamentoplasty with or without meniscal repair
* Patient with reducible flatus \>10° at 1 month post ligamentoplasty

Exclusion Criteria:

* Revision ligamentoplasty
* Multi-ligament knee
* Patient under court protection, guardianship or trusteeship
* Patient not affiliated to the French social security system
* Patient participating in another therapeutic protocol
* Pregnant woman or woman of childbearing age without effective contraception
* Patient unable to understand the informed information and/or to give written informed consent: dementia, psychosis, disturbed consciousness, non-French speaking patient
* Patient with known hypersensitivity to botulinum toxin
* Patient with peripheral neuromuscular dysfunction or pronounced atrophy of the semitendinosus muscle
* Patient treated with anticoagulants, chloroquine (or hydroxychloroquine)
* Patient treated in the previous seven days with antibiotics or muscle relaxants (such as tubocurarine)

Where this trial is running

Paris

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: Hamstring Contractures

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.