Age / Sex : 71 / F

Chief complaint : left foot pain (onset: 2mo ago), dystonia of left foot, on medication for parkinson disease

What is your diagnosis?

Two weeks later, you can see the final diagonosis with a brief discussion of this case (Please submit only one answer).


Courtesy : 정혜원 Hye Won Chung, 서울아산병원 Asan Medical Center

Cuboid Pulley Lesion

Discussion

Findings:

Bone marrow edema is noted at the lateral and plantar ridge of the cuboid (arrow head), which is wrapped by the peroneus longus tendon (arrow).

Peroneus longus tendon shows swelling and subtle enhancement at the lateral aspect of plantar foot near the cuboid bone. Tendon sheath is thickened and diffusely enhanced.

These findings suggest tendinosis and tenosynovitis of peroneus longus tendon.

Differential Diagnosis:

Acute traumatic tendon injury

Neuropathic arthropathy

Osteomyelitis and infectious tenosynovitis

Inflammatory tenosynovitis

Painful os peroneum syndrome

Discussion:

The cuboid acts as a bony pulley for the peroneus longus tendon. Peroneus longus tendon changes its direction as it wraps around the cuboid ridge. Thus muscle contraction from the midstance through the late propulsive phase exerts an eversion torque on the cuboid through the peroneus longus tendon. In a wraparound region against the bony surface, the tendon experiences mechanical stress. When compressive stress is added perpendicularly to the direction of the tendon fiber in the wraparound region, tendon experiences local pressure near the contact surface. So the cuboid pulley also endures local stress on the contact surface against the tendon.

Significant associations exist between cuboid pulley lesions and peroneal tenosynovitis, Achilles enthesitis, and inflammatory arthritis

There are four peroneus longus pulleys: lateral malleolus, peroneal notch of calcaneus, peroneal groove of cuboid, and base of 1st MT bone and medial cuneiform. Tendon changes its direction at these points.

 References:

MRI of cuboid pulley lesion.  AJR 2018; 211:867–871

imaging features. Radiographics 2005:25;587-602

https://epos.myesr.org/posterimage/esr/ecr2015/129247/media/612751