Citation, DOI & article data
Meniscocapsular separation refers to detachment of the meniscus from its capsular attachments. It is an uncommon injury.
Clinical findings are nonspecific and can include pain, instability, and joint effusion.
- it is more common in the medial (more frequently posterior horn region 5) than in the lateral compartment of the knee
- ramp lesions are a specific type of meniscocapsular injury associated with ACL-deficient knees 6
- meniscofemoral detachment is more common than meniscotibial detachment 4
While it can uncommonly occur in isolation, it is more often associated with other ligamentous injuries.
Meniscocapsular separation is usually diagnosed arthroscopically and the positive predictive value (PPV) of MRI has been traditionally described as being low 3 (as low as 9% medially and 13% laterally).
Low predictive value MRI findings that have been correlated with meniscocapsular separation include 1-2:
- interposition of fluid between the meniscus and the medial collateral ligament
- meniscal corner tears: according to one study had a PPV of 0% medially and 50% laterally 3
- perimeniscal fluid
- meniscofemoral and meniscotibial extension tears
- irregular meniscal outline
- increased distance between the meniscus and the medial collateral ligament
- visualization of fluid from the superior all the way to the inferior end of the meniscus has been described as a more suggestive feature 5 (PPV unknown)
On MR arthrography meniscocapsular separations have been correlated with interposition of contrast medium between the meniscus and the medial collateral ligament.
Treatment and prognosis
It may heal after conservative treatment or after re-suturing the meniscus into the capsule.
Potential complications include:
- increased meniscal mobility and resultant meniscal tears 5
- 1. De Maeseneer M, Lenchik L, Starok M et-al. Normal and abnormal medial meniscocapsular structures: MR imaging and sonography in cadavers. AJR Am J Roentgenol. 1998;171 (4): 969-76. doi:10.2214/ajr.171.4.9762977 - Pubmed citation
- 2. De Maeseneer M, Shahabpour M, Vanderdood K et-al. Medial meniscocapsular separation: MR imaging criteria and diagnostic pitfalls. Eur J Radiol. 2002;41 (3): 242-52. Pubmed citation
- 3. Rubin DA, Britton CA, Towers JD et-al. Are MR imaging signs of meniscocapsular separation valid?. Radiology. 1996;201 (3): 829-36. doi:10.1148/radiology.201.3.8939239 - Pubmed citation
- 4. Callaghan JJ, Rosenberg AG, Rubash HE et-al. The adult knee. LWW. ISBN:0781732476. Read it at Google Books - Find it at Amazon
- 5. Musculoskeletal Imaging. Saunders. (2014) ISBN:1455708135. Read it at Google Books - Find it at Amazon
- 6. Yujin Yeo, Joong Mo Ahn, Hyorin Kim, Yusuhn Kang, Eugene Lee, Joon Woo Lee, Heung Sik Kang. MR evaluation of the meniscal ramp lesion in patients with anterior cruciate ligament tear. (2018) Skeletal Radiology. 47 (12): 1683. doi:10.1007/s00256-018-3007-4 - Pubmed