A contribution to Pisani’s sign for diagnosing lateral meniscal cysts: a technical report

Abstract

This article describes modified physical examination maneuvers for diagnosing lateral meniscal cysts. The typical presentation of lateral meniscal cysts usually makes their clinical diagnosis simple, but a wide variation in size may sometimes lead to misdiagnosis. We evaluated the effect of leg rotations on the cystic swelling at 45 degrees of knee flexion. Eleven consecutive patients with positive Pisani's sign were evaluated prospectively. Lateral mid-third joint-line swelling was most prominent at 30-45 degrees of knee flexion. With the knee held at 45 degrees of flexion, the prominence was also inspected during internal and external rotation of the leg. The masses became noticeably more prominent with external rotation, and completely disappeared with internal rotation. With external rotation of the leg, even doubtful lateral meniscal cysts became apparent. Disappearance of the cystic mass with internal rotation further confirms the diagnosis.

Comparison of the recurrence risk of parameniscal cysts between patients treated with arthroscopic excision and arthroscopic decompression techniques

“…Since parameniscal cysts possess a multilobulated structure and an irregular shape, not every case is suitable for intra‐articular decompression [10, 19, 20]. Complete destruction of the intra‐cystic septa through the connecting tract to balance the pressure between the bilateral ends is difficult, particularly in large cysts that occupy a more extensive area [4, 16, 17].…”

Meniscus Tears in Children

“…Signs and symptoms include pain, swelling, and tenderness along the joint line, sometimes associated with a mass that is firmly fixed to the underlying tissues and not mobile in the subcutaneous tissues. 54 In 1947, Pisani 55 described the disappearance of the mass on flexion of the knee with the reappearance during extension as pathognomonic for lateral cysts.…”

Meniscal Cysts: Treatment Options and Algorithm

“…24 More recently, an internal and external rotation test was described. 25 With the knee held at 45 degrees of flexion, lateral meniscal cysts become noticeable more prominent with external rotation of the knee and completely disappear with internal rotation. 25 Given the strong association with meniscal tears, most clinicians supplement their physical exam findings with MRI to further evaluate the soft tissue pathology about the knee.…”

“…25 With the knee held at 45 degrees of flexion, lateral meniscal cysts become noticeable more prominent with external rotation of the knee and completely disappear with internal rotation. 25 Given the strong association with meniscal tears, most clinicians supplement their physical exam findings with MRI to further evaluate the soft tissue pathology about the knee. MRI is currently considered the gold standard in preoperative evaluation of meniscal cysts, although data concerning its true sensitivity and specificity are lacking in the literature.…”