Methods for aiding in the diagnosis and evaluation of a subject who has sustained an orthopedic injury and that has or may have sustained an injury to the head, such as mild traumatic brain injury (TBI), using glial fibrillary acidic protein (GFAP) and/or ubiquitin carboxy-terminal hydrolase L1 (UCH-L1)

A method comprising:

• a. performing at least one assay for ubiquitin carboxy-terminal hydrolase L1 (UCH-L1), glial fibrillary acidic protein (GFAP), or a combination thereof in at least one sample that is whole blood, serum, plasma, or cerebrospinal fluid obtained from a human subject within about 48 hours after the subject has sustained an orthopedic injury and an actual or suspected injury to the head;
• and
• b. performing a head computed tomography (CT) scan on the subject when the:
• (i) level of GFAP in the sample is equal to a reference level of GFAP of from about 140 pg/mL to about 1150 pg/mL, (ii) level of UCH-L1 in the sample is equal to a reference level of UCH-L1 of from about 400 pg/mL to about 810 pg/mL, or (iii) level of GFAP in the sample is equal to a reference level of GFAP of from 140 pg/mL to about 1150 pg/mL and the level of UCH-L1 in the sample is equal to a reference level of UCH-L1 of from about 400 pg/mL to about 810 pg/mL.

A method comprising:

• a. performing at least one assay for ubiquitin carboxy-terminal hydrolase L1 (UCH-L1), glial fibrillary acidic protein (GFAP), or a combination thereof in at least one sample that is whole blood, serum, plasma, or cerebrospinal fluid obtained from a human subject within about 48 hours after the subject has sustained an orthopedic injury and an actual or suspected injury to the head;
• and
• b. treating the subject for:
• (a) a moderate to severe TBI when the:
• (i) level of GFAP in the sample is equal to or greater than a reference level of GFAP of about 205 pg/mL to about 3000 pg/mL, (ii) level of UCH-L1 in the sample is equal to or greater than a reference level of UCH-L1 of about 215 pg/mL to about 3000 pg/mL, or (iii) level of GFAP in the sample is equal to or greater than a reference level of GFAP of about 205 pg/mL to about 3000 pg/mL and the level of UCH-L1 in the sample is equal to or greater than a reference level of about 215 pg/mL to about 3000 pg/mL;
• or
• (b) a mild TBI when the:
• (i) level of GFAP in the sample is less than a reference level of GFAP of about 205 pg/mL, (ii) level of UCH-L1 in the sample is less than a reference level of UCH-L1 of about 215 pg/mL, or (iii) level of GFAP in the sample is less than a reference level of GFAP of about 205 pg/mL and the level of UCH-L1 in the sample is less than a reference level of about 215 pg/mL.