Overview
Anterior cruciate ligament (ACL) rupture is a common and clinically significant injury, particularly among young, active, and athletic adults, and may lead to knee instability and functional impairment. The resulting instability can limit activities of daily living and reduce sports performance, often increasing the need for surgical treatment in physically active individuals. Therefore, ACL reconstruction is widely accepted as an effective treatment option in appropriately selected patients.
In the assessment of patients undergoing ACL reconstruction, not only postoperative clinical success but also the degree of preoperative instability may be important. Determining the effect of preoperative instability severity and side-to-side difference on postoperative functional outcomes, clinical recovery, radiological findings, return to daily activities, and return to sports may provide a more comprehensive and objective evaluation of surgical success.
Although several studies have investigated clinical outcomes after ACL reconstruction, prospective studies evaluating the impact of preoperative instability on postoperative outcomes together with clinical, functional, and radiological parameters remain limited, particularly in our country.
This prospective study aims to investigate the relationship between preoperative knee instability and postoperative clinical, functional, and radiological outcomes in patients undergoing ACL reconstruction at our institution. The findings are expected to contribute to the existing literature and provide useful information for clinical practice.
Description
Functional Assessment
To evaluate postoperative functional recovery, the Lysholm Knee Score, IKDC-2000 score, and Lachman test, which are routinely used in our clinical practice, will be applied. In addition, the time required for patients to return to activities of daily living, sports participation, and their usual daily routines will be recorded. The maintenance of postoperative well-being, the time required to resume preoperative sporting activities, and whether full functional recovery is achieved will also be analyzed.
During the preoperative period, patients will undergo a detailed physical examination for knee instability. Objective instability will be assessed using a Rolimeter, and the measured anterior tibial translation will be compared with the contralateral healthy knee to determine the degree of preoperative side-to-side instability. The association between preoperative instability severity and postoperative clinical and functional outcomes will subsequently be evaluated.
Surgical and Reconstruction Technique
Anterior cruciate ligament reconstruction will be performed according to the standard surgical principles routinely applied at our institution, in accordance with current literature, evidence-based practice, and contemporary scientific recommendations. Intraoperative variables, including graft type, graft harvest site, graft size, and femoral and tibial tunnel placement, will be recorded. The relationship between these surgical parameters and postoperative clinical and functional outcomes will also be assessed.
Radiological and Clinical Follow-Up
Patients will undergo routine postoperative radiological and clinical evaluations. On postoperative day 0, standard anteroposterior and lateral knee radiographs together with routine computed tomography imaging will be obtained to assess tunnel position and the early characteristics of the reconstruction.
At the 3-month follow-up, the effectiveness of the rehabilitation program and the patient's functional status will be evaluated by physical examination, computed tomography, and radiographs. At the 6-month follow-up, return to an active lifestyle and sports participation will be assessed together with clinical and radiological findings. During follow-up, tunnel position, tunnel dimensions, graft adaptation, and the healing process will be evaluated radiologically.
Complications and Local Evaluation
Postoperative complications occurring during follow-up will be recorded in detail. These will include infection, tunnel widening, fracture, wound-healing problems, tunnel malposition, graft laxity, recurrent clinical instability, and graft rerupture. All complications will be analyzed together with clinical examination findings and radiological assessments.
Statistical Analysis
All collected data will be analyzed using appropriate statistical methods. The effects of graft type, graft size, graft harvest site, and femoral and tibial tunnel dimensions and positions on return to normal active life and sports, functional recovery, and postoperative clinical outcomes will be evaluated.
In addition, the relationship between the degree of preoperative knee instability and postoperative clinical, functional, and radiological outcomes will be statistically assessed.
Through this methodological approach, the study aims to identify factors associated with postoperative functional outcomes following anterior cruciate ligament reconstruction and to evaluate the influence of graft characteristics and femoral and tibial tunnel placement on clinical success.
Eligibility
Inclusion Criteria:
Patients aged 18-50 years.
Patients diagnosed with unilateral anterior cruciate ligament (ACL) injury.
Patients scheduled to undergo primary ACL reconstruction.
Patients who are willing and able to complete a postoperative follow-up period of at least 6 months.
Patients with available postoperative radiological assessments, including computed tomography (CT), magnetic resonance imaging (MRI), and/or standard radiographs, as required by the study protocol.
Patients with clinical outcome assessments, including the Lysholm Knee Score and International Knee Documentation Committee (IKDC) score, recorded during the planned follow-up period.
Exclusion Criteria:
Patients with multiligament knee injuries, including clinically significant concomitant posterior cruciate ligament (PCL), medial collateral ligament (MCL), or lateral collateral ligament (LCL) injuries.
Patients with a history of previous non-ACL surgery on the affected knee.
Patients with advanced knee osteoarthritis.
Patients who develop a postoperative infection.
Patients with insufficient or inadequate radiological imaging data for the planned assessments.
Patients who do not complete at least 6 months of postoperative follow-up.
Patients with neuromuscular disorders or systemic connective tissue diseases.
Patients with incomplete or inadequately recorded clinical outcome scores.


