External Rotation Stress Test
Purpose
The External Rotation Stress Test originally came from Mark Boytin who wanted to differentiate between lateral ankle sprains and syndesmotic ankle sprains in footballers[1]. The authors observed that football players with syndesmotic ankle sprains took longer to recover. Over time and through cadaver studies, this test has been included in determining laxity in the deltoid ligament as well because the integrity of this ligament could play a factor in ankle instability[2] [3][4].
Technique
The original article describes the test in the following manner:
- Patient is seated with the knee at 90 degrees
- Place the foot/ankle in a neutral position
- Stabilize the lower leg
- Grasping the medial aspect of the calcaneus, take the foot into external rotation
A positive is production of pain over the anterior and/or posterior tibiofibular ligaments and over the interosseous membrane.
Evidence
A meta-analysis compared several external rotation and gravity stress test to diagnose a deltoid ligament or syndesmosis injury[5]. When it came to the diagnosis of a deltoid ligament injury, the external rotation stress test was found to have a pooled sensitivity of 63% and a pooled specificity of 64%. For the diagnosis of a syndesmosis injury, the pooled sensitivity was fond to be 33% and pooled specificity was 100%.
References
- ↑ Boytim, M. J., Fischer, D. A., & Neumann, L. (1991). Syndesmotic ankle sprains. The American journal of sports medicine, 19(3), 294-298
- ↑ Longo UG, Loppini M, Fumo C, et al. Deep deltoid ligament injury is related to rotational instability of the ankle joint: a biomechanical study. Knee Surg Sports Traumatol Arthrosc. 2021;29:1577–1583
- ↑ Starkey C, Brown SD. Examination of orthopedic & athletic injuries. FA Davis; 2015 Feb.
- ↑ de Vries JS, Kerkhoffs GM, Blankevoort L, van Dijk CN. Clinical evaluation of a dynamic test for lateral ankle ligament laxity. Knee Surg Sports Traumatol Arthrosc. 2010 May;18(5):628-33.
- ↑ Cao, S., Wang, C., Chen, Y., Zhang, C., Huang, J., Ma, X., & Wang, X. (2023). Stress tests for deltoid ligament and syndesmosis injury in patients with ankle fracture: a systemic review with meta-analysis. Journal of Orthopaedic Trauma, 37(11), e441-e446