Cyclops Syndrome After Anterior Cruciate Ligament Reconstruction (SCALA)

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

Monocentric, prospective, randomised, double-blind study of two parallel groups of 66 patients with post-reconstruction ACL hamstring contracture treated with an ultrasound-guided injection at two points on the body of the hamstring

• Group 1: botulinum toxin: 100 units (0.5ml) in 1 injection
• Group 2: placebo: 0.5 ml in 1 injection

Study Overview

• Status: Terminated
• Conditions: Hamstring Contractures
• Intervention / Treatment: Drug: Botulinum toxin; Other: Placebo

Detailed Description

The study includes three assessments: one month after ligamentoplasty (inclusion visit) and then at M2 and M5. The therapeutic benefit of the study treatments is based on the evolution of the extension defect at M2.

• Study Type: Interventional
• Enrollment (Actual): 13
• Phase: Phase 3

Contacts and Locations

Study Locations

• France
  • Paris, France, 75005
    • Clinique du Sport

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

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)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Group 1; botulinum toxin: 100 units (0.5ml) in 1 injection	Drug: Botulinum toxin; 100 units (0.5ml) in 1 injection
Placebo Comparator: Group 2; Placebo: 0.5 ml in 1 injection	Other: Placebo; Placebo 0.5 ml in 1 injection

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The percentage of therapeutic success, defined by the absence of extension defect at M3 post ligamentoplasty, will be compared between the groups by a Chi-2 test.	Therapeutic success is defined by the absence of extension defect (0 degree of flessum) at 2 months post botulinum toxin injection	Month 2

Collaborators and Investigators

• Sponsor: GCS Ramsay Santé pour l'Enseignement et la Recherche
• Investigators: Principal Investigator: Alexandre Hardy, MD, Clinique du Sport

Study record dates

Study Major Dates

• Study Start (Actual): July 18, 2024
• Primary Completion (Actual): February 20, 2026
• Study Completion (Actual): February 20, 2026

Study Registration Dates

• First Submitted: August 16, 2021
• First Submitted That Met QC Criteria: August 16, 2021
• First Posted (Actual): August 17, 2021

Study Record Updates

• Last Update Posted (Actual): June 5, 2026
• Last Update Submitted That Met QC Criteria: June 3, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Joint Diseases; Musculoskeletal Diseases; Muscular Diseases; Contracture; Amino Acids, Peptides, and Proteins; Proteins; Biological Factors; Hydrolases; Enzymes; Enzymes and Coenzymes; Metalloendopeptidases; Endopeptidases; Peptide Hydrolases; Metalloproteases; Bacterial Proteins; Bacterial Toxins; Toxins, Biological; Botulinum Toxins
• Other Study ID Numbers: 2020-005742-42

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No