Comparison of Knee Muscle Function After Suprapatellar and Infrapatellar Tibial Nailing in Patients With Tibial Shaft Fractures

The goal of this observational study is to compare the recovery of knee muscle strength and function in adults aged 18 to 65 years with a fracture in the middle part of the shinbone. All participants are treated with an intramedullary nail, which is a metal rod placed inside the shinbone. The nail is inserted through a surgical opening either above or below the kneecap. The main question this study aims to answer is: Does the recovery of the muscles that straighten the knee differ between the suprapatellar approach, performed above the kneecap, and the infrapatellar approach, performed below the kneecap? Researchers will compare participants who received the suprapatellar approach with those who received the infrapatellar approach. The treating surgical team chooses the approach as part of routine medical care. The researchers do not assign participants to either surgical approach. Participants will attend routine follow-up visits at 3 and 6 months after surgery. During these visits, researchers will: Measure the strength of the muscles that bend and straighten the knee and compare the operated leg with the uninjured leg Assess the participant's ability to sense the position of the knee Measure knee movement and thigh circumference Ask participants about knee function and pain in the front of the knee The researchers expect that recovery of the muscles that straighten the knee may differ between the two surgical approaches.

Inclusion Criteria: Age between 18 and 65 years Acute tibial shaft fracture classified as AO type 42 Treatment with intramedullary nailing using a suprapatellar or infrapatellar approach Provision of written informed consent to participate in the study Exclusion Criteria: Previous knee surgery. Concomitant knee ligament injury. Intra-articular fracture. Bilateral fractures. Neurovascular injury. Multiple trauma that may affect knee extensor strength, including an ipsilateral femoral fracture or pelvic fracture.