Knee Extension Deficit Following an Anterior Cruciate Ligament Reconstruction (Extension Loss)

Investigating the Knee Extension Deficit on Knee Strength Recovery Following an Anterior Cruciate Ligament Reconstruction

Knee extension loss following an anterior cruciate ligament (ACL) reconstruction is believed to play an important role in quadriceps strength recovery. One of the main goals of the rehabilitation following ACL reconstruction is to restore knee extensor muscle strength. Deficits of more than a five-degree extension range of motion (ROM) could lead to delayed knee functionality and anterior knee pain. However, the effect of knee extension deficits in the early postoperative phase of the ACL reconstruction on knee extensor muscle strength recovery and knee functionality is not yet known.

This study aimed to investigate the difference between knee extensor muscle strength recovery and knee functionality in patients with ACL repair who had a knee extension ROM deficit (>5°) in the early postoperative period and those who did not.

Study Overview

• Status: Recruiting
• Conditions: Anterior Cruciate Ligament Injuries
• Intervention / Treatment: Other: Extension Deficit (>5 degrees); Other: Extension Deficit (<5 degrees)

Detailed Description

Knee range of motion deficits are significant surgical complications following an anterior cruciate ligament (ACL) reconstruction, and despite current advances in surgical techniques, knee range of motion cannot always be regained. Previous studies reported that knee range of motion (ROM) deficits play an important role in knee extensor muscle weakness and knee osteoarthritis. Thus, deficits in knee extension joint motion are more difficult to tolerate than flexion deficits. It has been reported that a five-degree decrease in the extension ROM of the affected knee compared to the healthy side can lead to secondary complications such as difficulty walking and anterior knee pain. However, the effect of knee extension deficits in the early postoperative phase of the ACL reconstruction on knee extensor muscle strength recovery and knee functionality is not yet known.

This study aimed to investigate the difference between knee extensor muscle strength recovery and knee functionality in patients with ACL repair who had a knee extension ROM deficit (>5°) in the early postoperative period and those who did not.

• Study Type: Interventional
• Enrollment (Estimated): 30
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Leyla Eraslan, Ph. D.; Phone Number: +905348488373; Email: leylaseraslan@gmail.com

Study Locations

• Turkey (Türkiye)
  • Ankara, Turkey (Türkiye), 06100
    • Recruiting
    • Hacettepe University, Faculty of Physical Therapy and Rehabilitation
    • Contact: Leyla ERASLAN, Prof; Email: leylaseraslan@gmail.com
    • Contact: Volga Bayrakcı Tunay, Prof

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Patients who underwent ACL repair using hamstring tendon autograft
• volunteered to participate in the study between the ages of 18-45
• a non-contact injury mechanism
• a Tegner Activity Score >5 before the injury
• regularly attended the rehabilitation program after surgery (not missing more than three sessions)

Exclusion Criteria:

• Patients who underwent ACL repair with patellar tendon autograft or allograft, revision surgery
• underwent meniscus and or cartilage repair in addition to ACL repair
• a history of previous knee, ankle, or groin injuries
• concomitant systemic and/or neurological pathologies
• a history of injury to the contralateral lower extremity
• do not want to participate in the evaluations that should be done before the study.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Extension Deficit (>5 degrees); Patients who had a knee extension ROM deficit of more than 5 degrees in the fourth week will be subject to the rehabilitation program under the supervision of the same physiotherapist 3 days a week for a period of 12 weeks. The rehabilitation program will include cold therapy, electrotherapy, and exercises focusing on improving knee functioning and restoring muscle strength. From 12 weeks to 6 months, a home exercise program will be advised to all patients equally.	Other: Extension Deficit (>5 degrees); Patients who had a knee extension ROM deficit of more than 5 degrees will included
Active Comparator: Extension Deficit (<5 degrees); Patients who had a knee extension ROM deficit of less than 5 degrees in the fourth week will be subject to the rehabilitation program under the supervision of the same physiotherapist 3 days a week for a period of 12 weeks. The rehabilitation program will include cold therapy, electrotherapy, and exercises focusing on improving knee functioning and restoring muscle strength. From 12 weeks to 6 months, a home exercise program will be advised to all patients equally.	Other: Extension Deficit (<5 degrees); Patients who had a knee extension ROM deficit of less than 5 degrees will included

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Quadriceps Muscle Strength Recovery	Isometric, concentric and eccentric quadriceps muscle strength will be measured using an isokinetic dynamometer (IsoMed®2000 D&R GmbH, Germany).	Qudriceps muscle strength will be measured at 4th weeks (isometric), 12 th weeks (isometric and concentric), 6th months (isometric, concentric, and eccentric) following a surgery.
Hamstring Muscle Strength Recovery	Isometric, concentric and eccentric hamstring muscle strength will be measured using an isokinetic dynamometer (IsoMed®2000 D&R GmbH, Germany).	Hamstring muscle strength will be measured at 4th weeks (isometric), 12 th weeks (isometric and concentric), 6th months (isometric, concentric, and eccentric) following a surgery.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The Y Balance Test. Functional Testing 1	The Y Balance Test will be used. Three repetitions will be conducted for each limb, and mean values were recorded in centimeters.	Assessments will be conducted at 12th weeks and 6th months following a surgery
The Vertical Jump Test. Functional Testing 2	The Vertical Jump Test will be used. Three repetitions will be conducted for each limb, and mean values were recorded in centimeters.	Assessments will be conducted at 12th weeks and 6th months following a surgery
The Single Leg Hop Test. Functional Testing 3	The Single Leg Hop Test will be used. Three repetitions will be conducted for each limb, and mean values were recorded in centimeters	Assessments will be conducted at 12th weeks and 6th months following a surgery
The Lysholm score. Patient-reported outcomes measures 1	The Lysholm score will be used to assess self-reported recovery. The Lysholm score is an eight-item questionnaire that evaluates patients following knee ligament injury. This is scored on a 100-point scale from 0 (worst symptoms) to 100 (best symptoms), with 25 points attributed to pain, 15 to locking, 10 to swelling, 25 to instability,10 to stair climbing and 5 points each to limping, use of a support and squatting.	Self-reported recovery will be recorded at 12th weeks and 6th months following a surgery
The International Knee Documentation Committee subjective knee form (IKDC). Patient-reported outcomes measures 2	The International Knee Documentation Committee subjective knee form (IKDC) will be used to assess self-reported recovery. IKDC subjective knee form contains 18 selected items designed to measure symptoms. Total IKDC score ranges from 0 to 100, with 100 indicating the absence of symptoms and higher levels of knee function.	Self-reported recovery will be recorded at 12th weeks and 6th months following a surgery

Collaborators and Investigators

• Sponsor: Hacettepe University
• Investigators: Principal Investigator: Leyla Eraslan, Ph. D., Hacettepe University

Study record dates

Study Major Dates

• Study Start (Actual): March 15, 2025
• Primary Completion (Estimated): March 15, 2026
• Study Completion (Estimated): July 15, 2026

Study Registration Dates

• First Submitted: February 22, 2025
• First Submitted That Met QC Criteria: March 6, 2025
• First Posted (Actual): March 7, 2025

Study Record Updates

• Last Update Posted (Estimated): September 12, 2025
• Last Update Submitted That Met QC Criteria: September 11, 2025
• Last Verified: September 1, 2025

More Information

Terms related to this study

• Keywords: ACL; knee; reconstruction; extension deficit
• Additional Relevant MeSH Terms: Wounds and Injuries; Leg Injuries; Knee Injuries; Anterior Cruciate Ligament Injuries
• Other Study ID Numbers: 2024/140

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No