Preoperative Magnetic Resonance Imaging as a Diagnostic Aid for Hypermobile Lateral Meniscus

Abstract

Background: Hypermobile lateral meniscus is difficult to diagnose with imaging due to its absence of tears or anomalies. We aimed to clarify the accuracy of the preoperative diagnosis using magnetic resonance imaging (MRI). Methods: The preoperative MRI status of the posterosuperior popliteomeniscal fascicle (sPMF), anteroinferior popliteomeniscal fascicle (iPMF), and popliteal hiatus were examined retrospectively on sagittal images in the hypermobile lateral meniscus group (n = 22) and an age- and gender-matched control group (n = 44). These statuses were evaluated by a logistic regression analysis to assess their degree of diagnostic accuracy. Results: The area under the curve (AUC) of the sPMF, iPMF, popliteal hiatus, and all three criteria combined was 0.66, 0.74, 0.64, and 0.77, respectively (low, moderate, low, and moderate accuracy, respectively). The odds ratios of the most severe type 3 forms of the sPMF, iPMF, and popliteal hiatus for hypermobile lateral meniscus were significantly high (5.50, 12.20, and 5.00, respectively). Although the diagnostic accuracy was not high enough, the significantly higher odds ratio for type 3 may indicate a hypermobile lateral meniscus. Conclusion: a definitive diagnosis of hypermobile lateral meniscus is difficult with MRI findings alone; however, MRI evaluations of the iPMF, sPMF, and the widening of popliteal hiatus can be used as an adjunct to diagnosis.

Surgical Repair of Hypermobile Lateral Meniscus Secondary to Popliteomeniscal Fascicle Tears Improves Pain and Mechanical Symptoms

“…investigated the diagnostic accuracy of MRI for isolated hypermobile lateral meniscus. 16 With a cohort of 66 patients—22 HLM patients matched 2:1 to controls—researchers demonstrated that upon MRI assessment of the integrity of the sPMF, iPMF, and popliteal hiatus in each knee by 2 blinded orthopedic surgeons, there was a statistically significant odds ratio for a diagnosis of HLM in the setting of worse preoperative MRI findings within each structure (sPMF OR 5.50 [ P = .036]; iPMF 12.20 [ P = . 002]; popliteal hiatus 5.00 [ P = .034]).…”

Hypermobile lateral meniscus: A systematic review of current treatment options

“…Congenital or traumatic insufficiencies of the PMF are highlighted as a common cause of HLM [52]. The PMF are posterolateral meniscocapsular extensions that proceed inferiorly from the external edge of the LM to the popliteus musculotendinous complex, asserting a significant impact on rotational stability of the knee and restricting anterior displacement of the posterolateral portion of the LM [16,36,47,48].…”