Orthopedics Hip & Knee Knee Ligament Injuries Posterolateral Rotatory Instability of the Knee By Jonathan Cluett, MD Jonathan Cluett, MD LinkedIn Twitter Jonathan Cluett, MD, is a board-certified orthopedic surgeon with subspecialty training in sports medicine and arthroscopic surgery. Learn about our editorial process Updated on August 02, 2022 Medically reviewed Verywell Health articles are reviewed by board-certified physicians and healthcare professionals. These medical reviewers confirm the content is thorough and accurate, reflecting the latest evidence-based research. Content is reviewed before publication and upon substantial updates. Learn more. by Eva Umoh Asomugha, M.D. Medically reviewed by Eva Umoh Asomugha, M.D. LinkedIn Eva Umoh Asomugha, MD, is a board-certified orthopedic surgeon who specializes in all conditions involving the foot and ankle region. She is based in northern Virginia. Learn about our Medical Expert Board Fact checked Verywell Health content is rigorously reviewed by a team of qualified and experienced fact checkers. Fact checkers review articles for factual accuracy, relevance, and timeliness. We rely on the most current and reputable sources, which are cited in the text and listed at the bottom of each article. Content is fact checked after it has been edited and before publication. Learn more. by Zerah Isaacs Fact checked by Zerah Isaacs Zerah Isaacs is a technical research assistant with experience in both academic and industry biomedical research. Learn about our editorial process Print Posterolateral rotatory instability can occur due to damage to the structures that support the outside of the knee joint, described as the posterolateral corner. These structures are critical to preventing symptoms of knee instability. An injury of the knee ligaments can affect the structures of the posterolateral corner. These structures include the lateral collateral ligament, the popliteus tendon, and the knee joint capsule. They can be injured when the knee sustains ligament damage—including ACL tears and PCL tears. If damage to the posterolateral corner is not treated, persistent knee problems can occur, despite treatment of other knee injuries. Westend61 / Getty Images Symptoms of Posterolateral Corner Injuries Posterolateral corner injuries often occur with knee dislocations. About 70% of posterolateral corner injuries occur in the setting of an injury to the ACL and/or PCL—also known as the cruciate ligaments. About 44% of posterolateral corner injuries cause palsy of the peroneal nerve. An injury to this nerve can cause numbness down the outside of the leg or weakness of the foot. About 20-30% of the time, an injury of the posterolateral corner is isolated. Symptoms of posterolateral corner injuries include: A feeling that the knee is going to give outPain and swelling over the outside of the knee joint, toward the back of the knee Your healthcare provider will perform a Dial test when examining your knee for posterolateral rotatory instability. During this test, your healthcare provider will determine the rotation of your knee (by turning your foot outwards at a specific position) and compare it to the opposite knee. Excessive rotation is indicative of an injury to the posterolateral corner. Your healthcare provider will check the degree of rotation at different levels of knee flexion to determine which structures have been injured. Treatment Treatment of a posterolateral corner injury depends on the degree of instability. This type of injury is considered a contributing reason for why some people might not improve after ACL reconstruction surgery. When posterolateral corner injuries cause significant instability in the knee joint, the structures can be surgically repaired. A surgical repair requires an incision along the outside of the knee joint. If the injuries to the ligament are recent, they can often be repaired without the use of donor tissue, whereas chronic injuries may require donor tissue to reconstruct the damaged structures. Severe injuries also generally require the use of some donor tissue to augment the repair along the outside of the knee. Rehab After Surgery Rehabilitation after posterolateral reconstruction will depend on which knee structures that have been injured and repaired. 7 Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Hughes JD, Rauer T, Gibbs CM, Musahl V. Diagnosis and treatment of rotatory knee instability. J EXP ORTOP. 2019;6(1):48. doi:10.1186/s40634-019-0217-1 Dean RS, LaPrade RF. ACL and posterolateral corner injuries. Curr Rev Musculoskelet Med. 2020;13(1):123-132. doi:10.1007/s12178-019-09581-3 Oshima T, Nakase J, Numata H, Takata Y, Tsuchiya H. Common peroneal nerve palsy with multiple-ligament knee injury and distal avulsion of the biceps femoris tendon. Case Reports in Orthopedics. 2015;2015:1-6. doi:10.1155/2015/306260 Chahla J, Moatshe G, Dean CS, LaPrade RF. Posterolateral corner of the knee: current concepts. Arch Bone Jt Surg. 2016;4(2):97-103. Welsh P, DeGraauw C, Whitty D. Delayed diagnosis of an isolated posterolateral corner injury: a case report. J Can Chiropr Assoc. 2016;60(4):299-304. Shon OJ, Park JW, Kim BJ. Current concepts of posterolateral corner injuries of the knee. Knee Surg Relat Res. 2017;29(4):256-268. doi:10.5792/ksrr.16.029 Franciozi CE, Albertoni LJB, Gracitelli GC, et al. Anatomic posterolateral corner reconstruction with autografts. Arthroscopy Techniques. 2018;7(2):e89-e95. doi:10.1016/j.eats.2017.08.053 Additional Reading Covey DC, "Injuries of the Posterolateral Corner of the Knee" J Bone Joint Surg (Am) 83:106 (2001) By Jonathan Cluett, MD Jonathan Cluett, MD, is board-certified in orthopedic surgery. He served as assistant team physician to Chivas USA (Major League Soccer) and the United States men's and women's national soccer teams. See Our Editorial Process Meet Our Medical Expert Board Share Feedback Was this page helpful? Thanks for your feedback! What is your feedback? Other Helpful Report an Error Submit