This is a study intended to evaluate a non-invasive device that uses light to measure the amount of oxygen in the muscles of injured and non-injured legs in specific situations. The name of this technology is NIRS (near-infrared spectroscopy). The goal of this study is to collect the information necessary to understand the use of the NIRS monitoring system to diagnose and direct treatment decisions in case of complications sometimes experienced in traumatic tibia fracture, such as excessive swelling called acute compartment syndrome (ACS).

This study seeks to further develop the use of NIRS technology in the diagnosis of acute compartment syndrome. NIRS values normally increase in traumatized legs compared to the contralateral uninjured leg or forearm, indicative of a hyperemic response. The investigators hopes to build upon the current knowledge and verify the ability to accurately detect ACS using two easily identified and accessible leg compartments, the anterior and superficial posterior utilizing the Nonin 7600 oximeter with the Sensor Model 8004CV. Additionally, since this device was originally designed with brain tissue in mind, the NIRS device will collect vital engineering data that will be used to validate the algorithm used to produce the oxygenation values in injured muscle tissue.

Inclusion Criteria:

• Unilateral leg injury
• Enrolled within 48 hours of injury
• Subjects with 'severe' leg injuries presenting at trauma center that meet at least one of the following from each group below:

Anatomic location:

• Tibia/Fibula shaft fracture
• Tibial plateau fracture (Schatzker III-VI)

High Energy Mechanism of Injury:

• Fall from >8 foot height
• Motor vehicle collision (> 15 mph)
• Motor vehicle versus pedestrian accident
• High velocity gunshot wound
• Crush injury
• Sport/recreation

Exclusion Criteria:

• Application of NIRS monitoring would be an impediment to care
• Known prior leg fractures, patient has already undergone fasciotomy of the injured leg prior to enrollment
• History of peripheral vascular disease or concurrent lower extremity vascular injury/surgery
• Admission for atraumatic medical reasons
• Subject is unable to provide informed consent, or consent cannot be obtained from a legally authorized representative
• Complete spinal cord injuries, bilateral upper extremity injuries, or amputation/mangled lower extremity
• Patients who are in police custody at presentation to the hospital or who are pregnant
• Patient has an open injury on the injured leg that is large enough that at least one NIRS sensor cannot be safely placed over the compartment
• Bilateral leg injuries
• Not able to be enrolled within 48 hours after injury

Subjects will be recruited from the trauma bay, surgical wards and ICU of Grady Memorial Hospital.