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

A Prospective Randomized Controlled Trial Comparing the Endobutton CL BTB Fixation System With Metal Interference Screws in the Femoral Fixation of Patellar Tendon Grafts in Anterior Cruciate Ligament Reconstruction.

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.

Study Overview

• Status: Recruiting
• Conditions: Knee Injuries
• Intervention / Treatment: Device: Endobutton CL BTB; Device: Metal interference screw

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.

• Study Type: Interventional
• Enrollment (Anticipated): 220
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Trond Olav Lundemo, md; Email: trond.olav.lundemo@stolav.no
• Study Contact Backup: Name: Tone Gifstad, md phd; Email: tone.gifstad@stolav.no

Study Locations

• Norway
  • Trondheim, Norway
    • Recruiting
    • Department of Orthopedic Surgery, St Olavs Hospital
  • Trondheim, Norway
    • Recruiting
    • Rosenborgklinikken
    • Contact: Agnar Tegnander, md phd

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 55 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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)

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Endobutton CL BTB; Femoral fixation of the BPTB autograft with the Endobutton CL BTB Fixation System.	Device: Endobutton CL BTB; ACL reconstruction with Endobutton CL BTB
Active Comparator: Metal interference screw; Femoral fixation of the BPTB autograft with a metal interference screw.	Device: Metal interference screw; ACL reconstruction with metal interference screw

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Knee related quality of life	KOOS subscale "knee related Quality of life (QOL)"	2 years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Tegner activity scale		6 months, 2 years, 10 years
Lachman test	Anterior translation of the tibia	6 weeks, 6 months, 2 years, 10 years
Muscular strength	Biodex dynamometer	6 months, 2 years, 10 years
Bone block integration	CT scan	6 months
Osteoarthritis	X-ray radiographs	2 years, 10 years
Range of motion		6 weeks, 6 months, 2 years, 10 years
Knee related quality of life	KOOS subscale "knee related Quality of life (QOL)"	6 weeks
Knee related quality of life	KOOS subscale "knee related Quality of life (QOL)"	6 months
Knee related quality of life	KOOS subscale "knee related Quality of life (QOL)"	10 years
Lysholm functional knee score		6 weeks, 6 months, 2 years, 10 years
KOOS	Knee injury and Osteoarthritis Outcome Score	6 weeks, 6 months, 2 years, 10 years
Pivot shift test	Anteroposterior and rotational stability	6 weeks, 6 months, 2 years, 10 years
KT-1000 arthrometer	Anterior translation of the tibia	6 weeks, 6 months, 2 years, 10 years

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Complications	Registration	Up to 10 years
Reoperations	Registration	Up to 10 years

Collaborators and Investigators

• Sponsor: St. Olavs Hospital
• Collaborators: Rosenborgklinikken
• Investigators: Principal Investigator: Jon Olav Drogset, md phd, St. Olavs Hospital

Study record dates

Study Major Dates

• Study Start (Actual): October 1, 2016
• Primary Completion (Anticipated): March 1, 2025
• Study Completion (Anticipated): March 1, 2033

Study Registration Dates

• First Submitted: June 20, 2016
• First Submitted That Met QC Criteria: September 27, 2016
• First Posted (Estimate): September 29, 2016

Study Record Updates

• Last Update Posted (Estimate): March 9, 2023
• Last Update Submitted That Met QC Criteria: March 8, 2023
• Last Verified: March 1, 2023

More Information

Terms related to this study

• Keywords: Anterior Cruciate Ligament; Bone-Patellar Tendon-Bone Grafting
• Additional Relevant MeSH Terms: Wounds and Injuries; Leg Injuries; Knee Injuries
• Other Study ID Numbers: 2015/993

Plan for Individual participant data (IPD)

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