Finochietto Sign

Finochietto Sign (or finochietto jump sign) simultaneously tests for anterior cruciate ligament ACL and meniscus injuries of the knee. This test was first described by Ricardo Finochietto in 1935.

How do you perform the Finochietto Sign?

The patient, supine on the examining table, flexes the knee to 90 degrees while keeping the foot on the table. The foot is externally rotated to test the medial meniscus or internally rotated to test the lateral meniscus. The examiner braces the foot by sitting sideways on it, then clasps his/her hands behind the proximal tibia just distal to the popliteal space and pulls strongly and steadily forward until the sign is elicited.

It may be necessary to pull with sufficient strength to move the patient on the examining table. If this does not displace the meniscus, a sudden jerk should be tried. Alternatively, the patient lies supine on the floor with the hip and knee flexed 90 degrees, and the tibia is pulled upward with sufficient force to lift the patient’s buttocks off the floor.

The patient must be advised prior to testing that the knee may lock and become painful, and possibly require surgery for reduction. Reduction following a positive jump sign is usually accomplished by applying a valgus and internal rotation force to the tibia in relation to the femur while passively or actively extending the knee. If the lateral meniscus displaces, the application of an external rotation and varus force to the knee will cause reduction.

See Also: Anterior Cruciate Ligament Injury

What is the positive Finochietto Sign?

Where the injury also involves an anterior cruciate ligament tear, the anterior drawer test with the knee flexed 90° will cause anterior displacement of the tibia.

The laxity of the knee ligaments causes the femoral condyle to ride up over the posterior horn of the medial meniscus under the stress of the anterior drawer.

A positive Finochietto test produces an audible snap and/ or a palpable skip. If the tibia is then pressed posteriorly, the femoral condyle will glide back down from the posterior horn of the medial meniscus.

Occasionally, reduction of the displaced meniscus will be necessary following a positive Finochietto test. In this case, there is reason to suspect a full posterior separation of the medial meniscus and/ or a longitudinal or bucket-handle tear.

Notes

Ricardo Finochietto described the Finochietto jump sign as a jerk produced during the passive movement of the head of the tibia under the femoral condyle. 

In the setting of anterior cruciate ligament insufficiency, damage to the posterior horn of the medial meniscus or its capsular attachments results from derangement of the rolling and sliding mechanism secondary to a cruciate ligament tear. This produces a shear injury to the posterior horn of the medial meniscus.

Ramp Lesion

Meniscal ramp lesions include the peripheral insertion of the posterior horn of the medial meniscus, they are usually associated with anterior cruciate ligament (ACL) tears.

The incidence of ramp lesions is variable: between 9% and 42% of ACL tears.

The Finochietto jump sign is a very specific finding that could be considered pathognomonic regarding ramp lesions. Ramp lesions are considered hidden injuries of the medial meniscus and are very difficult to diagnose.

Thaunat classified ramp lesions into 5 types depending on both tear pattern (partial- or full-thickness tear) and associated meniscotibial ligament disruption:

1. Type 1: meniscocapsular lesions;
2. Type 2: partial superior lesions;
3. Type 3: partial inferior or hidden lesions;
4. Type 4: complete tear in red-red zone;
5. Type 5: double tear.

References

1. R. Finochietto Semilunar cartilages of the knee. The “jump sign” J Bone Joint Surg, 17 (1935), pp. 916-921.
2. Losee RE. Finochietto’s “Jump Sign”. Pathognomonic Sign of a Posterior Longitudinal Tear of the Meniscus of the Knee. Iowa Orthop J. 1983;3:55–6. PMCID: PMC2328732. PubMed
3. Espejo-Baena A, Espejo-Reina A, Espejo-Reina MJ, Ruiz-Del Pino J. The Finochietto Sign as a Pathognomonic Finding of Ramp Lesion of the Medial Meniscus. Arthrosc Tech. 2020 Mar 31;9(4):e549-e552. doi: 10.1016/j.eats.2020.01.004. PMID: 32368477; PMCID: PMC7189623. PubMed
4. Thaunat M, Fayard JM, Guimaraes TM, Jan N, Murphy CG, Sonnery-Cottet B. Classification and Surgical Repair of Ramp Lesions of the Medial Meniscus. Arthrosc Tech. 2016 Aug 8;5(4):e871-e875. doi: 10.1016/j.eats.2016.04.009. PMID: 27709051; PMCID: PMC5040630.
5. Zhou M.L., Haley C.C.Meniscal Ramp Lesions and Root Tears: A Review of the Current LiteratureSports Medicine and Arthroscopy Review, Volume 29, 2021.
6. S.R. BollenPosteromedial meniscocapsular injury associated with rupture of the anterior cruciate ligament: A previously unrecognised associationJ Bone Joint Surg Br, 92 (2010), pp. 222-223.