Age / Sex : 40 / F

Age / Sex : F/40
           She was receiving medical treatment for SLE during 20 years

Chief complaint : right knee pain.

                 (She tripped and fell to the ground 1days ago)

1) What is your impression?

Two weeks later, you can see the final diagnosis with a brief discussion of this case.

* Send Application Answers to In Sook Lee, MD (lis@pusan.ac.kr)

Courtesy : Lee Seunghun,

acute patellar tendon rupture with patella alta

Discussion

Findings: Plain radiograph> Diffuse soft tissue calcification is evident in the right knee joint. This finding is occasionally observed in systemic lupus erythematosus. Soft tissue thickening is shown near tibial tuberosity. Patella alta is also shown.

MRI> On T1WI and T2WI, acute rupture of patellar tendon with patella alta is shown.

Differential Diagnosis:

Diagnosis: acute patellar tendon rupture with patella alta

Discussion:

Indirect forces applied to the extensor mechanism of the knee can lead to failure of one or more of itscomponents. Failure of the patella resulting in fracture is common, especially in adults. Systemic disorders such as RA, CRF, and SLE contribute to failure of the quadriceps and patellar tendon, may occur in the absence of these causative factors. Patellar tendon ruptures are not uncommon in persons with chronic patellar tendinosis. Failure of the patellar tendon usually occurs at its junction with the inferior pole of the patella or, less commonly, the tibial tuberosity, although intrasubstance disruption of patellar tendon may also occur. Complete tears of the patellar tendon are associated with a high position of the patella, designated patella alta. Incomplete tears are not associated with this change in patellar position.

References:

Resnick D.: Bone and joint imaging, 3^rd. Philadelphia: Elsevier-Saunders, 2005:963-965.