Fixation of Patellar Tendon Grafts in Anterior Cruciate Ligament Reconstruction. Endobutton vs Metal Interference Screws

NCT ID: NCT02918734

Last Updated: 2025-07-10

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: NA
• Total Enrollment: 220 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2016-10-31
• Study Completion Date: 2033-03-31

Brief Summary

In this randomized controlled trial the investigators will compare the results after primary anterior cruciate ligament (ACL) reconstruction using two different methods for femoral fixation of a bone-patellar tendon-bone (BPTB) autograft. Interference screws have been the standard method for fixing the femoral side of BPTB grafts; however, several pitfalls have been reported. Cortical fixation with the Endobutton CL BTB Fixation System has become available and the clinical results have been described as promising; however, no randomized controlled trials comparing these two femoral fixation methods have been conducted, and there is no published data that confirms that the bone block heals in the tunnel with the newer method.

The aim of our study is to compare the outcome after primary ACL reconstruction with BPTB autografts using the Endobutton CL BTB or metal interference screw for femoral fixation.

Detailed Description

Primary anterior cruciate ligament (ACL) reconstructions with bone-patellar tendon-bone (BPTB) autografts have recently been found to have a lower risk of revision compared with hamstring tendon autografts, and BPTB has again become our graft of choice. Interference screws have been the standard method for fixing the femoral side of a BPTB graft; however problems such as damage of the graft and failure due to nonparallel screw placement have been reported. Cortical fixation using a suspensory system has been used for soft-tissue graft fixation for several years, and a corresponding device, the Endobutton CL BTB Fixation System (Smith & Nephew, Inc., Andover, MA, USA), has become available for fixation of bone-tendon-bone grafts. The clinical results after fixation with the Endobutton CL BTB have been described as promising; however, no randomized controlled trials comparing these two fixation methods have been conducted, and there is no published data that confirms that the bone block heals in the tunnel with the newer method.

In this randomized controlled trial, patients undergoing primary ACL reconstruction will be randomized into either an Endobutton group or an interference screw group. The primary aim of the study is to compare these two fixation methods, assessed by patient reported outcomes, laxity, range of motion and muscle strength. Knee related quality of life 2 years after surgery is the primary outcome, measured by the Knee injury and Osteoarthritis Outcome Score (KOOS) subscale "knee related Quality of life (QOL)". Other aims are to see if there is any difference in the integration of the bone block in the femoral tunnel assessed by CT scan, in the risk of developing osteoarthritis assessed by radiographs, or in the risk of a postoperative complication or revision. The patients will be followed up 6 weeks, 6 months, 2 years and 10 years after surgery. CT scan will be performed after 6 months, and radiographs after 2 years and 10 years. In addition details of the rehabilitation will be recorded. Patients undergoing a revision will be followed up but excluded from further comparisons in the study.

Our hypothesis is that there is no difference in the outcome after primary ACL reconstruction with BPTB autografts using the Endobutton CL BTB or metal interference screw for femoral fixation, both with a metal interference screw for the tibial fixation.

Conditions

Knee Injuries

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: SINGLE

Study Groups

Endobutton CL BTB

Femoral fixation of the BPTB autograft with the Endobutton CL BTB Fixation System.

Group Type: EXPERIMENTAL

Endobutton CL BTB

Intervention Type: DEVICE

ACL reconstruction with Endobutton CL BTB

Metal interference screw

Femoral fixation of the BPTB autograft with a metal interference screw.

Group Type: ACTIVE_COMPARATOR

Metal interference screw

Intervention Type: DEVICE

ACL reconstruction with metal interference screw

Interventions

Endobutton CL BTB

ACL reconstruction with Endobutton CL BTB

Intervention Type: DEVICE

Metal interference screw

ACL reconstruction with metal interference screw

Intervention Type: DEVICE

Eligibility Criteria

Inclusion Criteria

• Primary reconstruction of ACL ruptures
• Surgery at least 6 weeks after injury
• The patient must accept and sign the informed consent form before surgery

Exclusion Criteria

• Medical indication for using another graft than BPTB autograft (such as history of anterior knee pain or occupations etc. requiring frequent kneeling)
• Previous major surgical procedures in the same knee
• Major additional injuries in the knee (posterior cruciate ligament, lateral collateral ligament, medial collateral ligament, sutured meniscus lesions and major cartilage lesions undergoing cartilage repair)
• Contralateral ACL injury (treated or untreated)
• Present or former serious illness that makes follow-up or rehabilitation difficult (e.g. alcohol or drug abuse, psychiatric disease)

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 55 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Rosenborgklinikken

UNKNOWN

Sponsor Role: collaborator

St. Olavs Hospital

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Jon Olav Drogset, md phd

Role: PRINCIPAL_INVESTIGATOR

St. Olavs Hospital

Locations

Department of Orthopedic Surgery, St Olavs Hospital

Trondheim, , Norway

Site Status: RECRUITING

Rosenborgklinikken

Trondheim, , Norway

Site Status: RECRUITING

Countries

Norway

Central Contacts

Trond Olav Lundemo, md

Role: CONTACT

TrondOlav.Lundemo@helse-nordtrondelag.no

Tone Gifstad, md phd

Role: CONTACT

tone.gifstad@stolav.no

Facility Contacts

Agnar Tegnander, md phd

Role: primary

Other Identifiers

2015/993

Identifier Type: -

Identifier Source: org_study_id