Anteromedial rotatory instability is an abnormal and excessive movement of the inner side of the tibia in relation to the femur when weight is taken on the knee, with the joint opening up more than it should.
Page updated July 2024 by Dr Sheila Strover (Clinical Editor)
What is the relevance of anteromedial rotatory instability?
The main relevance of identifying the particular nature of this instability is that surgical correction of any accompanying anterior cruciate ligament tear is likely to fail unless the rotatory instability is also addressed.
What causes anteromedial rotatory instability?
Anteromedial rotatory instability is usually the result of an injury with damage to several structures:
- medial collateral ligament
- medial meniscus
- anterior cruciate ligament
- posterior oblique ligament
It is one of the multiligament injuries of the knee.
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Quote from peer-reviewed paper:
"....While most [medial collateral ligament (MCL)] injuries can be treated nonoperatively, medial instability may remain, particularly with higher-grade injuries. Residual MCL laxity can impair knee function, cause chronic pain, and lead to higher rates of ACL reconstruction failure...."
Citation: Behrendt P, Herbst E, Robinson JR, von Negenborn L, Raschke MJ, Wermers J, Glasbrenner J, Fink C, Herbort M, Kittl C. The Control of Anteromedial Rotatory Instability Is Improved With Combined Flat sMCL and Anteromedial Reconstruction. Am J Sports Med. 2022 Jul;50(8):2093-2101. doi: 10.1177/03635465221096464. Epub 2022 May 23. PMID: 35604117; PMCID: PMC9227970.
Synonyms:
AMRI
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