Which test result is most consistent with a Grade I MCL sprain?

• A. Positive valgus stress test
• B. Negative valgus stress test
• C. Instability with varus stress
• D. Positive Lachman

Answer: (B)

Grade I MCL sprain means the ligament is mildly stretched with little to no tearing. Because the injury is so mild, the knee does not show increased valgus laxity when stressed. A valgus stress test would be negative, reflecting no abnormal gapping and indicating the ligament isn’t significantly torn. In contrast, a positive valgus test suggests more extensive MCL damage (Grade II or III) with measurable laxity. Tests that address other ligaments—like a varus stress test for the LCL or the Lachman for the ACL—do not fit an isolated Grade I MCL sprain, since those would point to different structures being injured. So a negative valgus stress test is the result most consistent with a Grade I MCL sprain.