ACL Surgery

The goal of this study is to improve understanding of tendon health and disease by using surplus tendon tissue that is routinely removed during planned orthopaedic surgeries in adults. The main questions it aims to answer are: \- What can tendon tissue and tendon cells tell us about how healthy and diseased tendons function? Participants will not undergo any extra procedures. Instead, researchers will use only tissue that is already being removed as part of normal surgical care and would otherwise be discarded. Participants will: * Be asked for permission (consent) before their surgery to donate any surplus tendon tissue. * Have a small piece of tendon tissue (normally waste material) collected during their planned operation. * Allow the research team to access some non-identifiable medical information (such as age, reason for surgery, and relevant medical history) to help interpret research findings. What the researchers will do with the donated tissue: * Isolate different types of human tendon cells. * Build advanced laboratory cellular models to study how tendon diseases develop. * Analyse whole tendon tissue sections to understand cell types, tissue organisation, and disease-related changes. This study does not involve testing treatments, and it does not change any aspect of a participant's clinical care. Although there is no direct benefit to participants, the donated tissue may help researchers develop better ways to study tendon injuries and improve future treatment options for tendon disease.

Opioids are commonly used after orthopedic surgery for pain control but have been shown to increase complications, surgeries, readmissions, and risk for opioid use disorder. The purpose of this study is to investigate the impact of adding a methylprednisolone taper to the pain regimen after ACL repair surgery to determine if this results in decreased postoperative pain and opioid use without increasing complications.

The goal of this clinical trial is to learn if a novel Knee Extensors Activation (KEA) device can improve quadriceps muscle activation in adults after anterior cruciate ligament (ACL) reconstruction surgery. The study focuses on adults aged 18-45 years undergoing primary unilateral ACL reconstruction, a population commonly affected by this injury. The main questions it aims to answer are: Does using the KEA device lead to greater quadriceps muscle activation (measured via EMG) by postoperative Day 5 compared to standard care using a rolled towel? Does the KEA device improve early knee function, reduce pain, and decrease fear of movement compared to the towel method? Researchers will compare participants using the KEA device versus a control group using the conventional rolled towel during early postoperative rehabilitation to see if the KEA device provides better outcomes. Participants will: Begin quadriceps strengthening exercises on the first day after ACL surgery. Be randomly assigned to use either the KEA device or a rolled towel for isometric quadriceps exercises. Perform 3 sets of 10 repetitions of knee extension exercises, twice daily for 5 consecutive days. Undergo assessment of quadriceps EMG activation and complete questionnaires (KOOS, IKDC, TSK, and VAS) on Day 5.