Knuckle pads

Last revised by Henry Knipe on 27 Jul 2023

Knuckle pads, also known as Garrod pads, Garrod nodes or holoderma, are benign, subcutaneous, fibrofatty growths that overlie the interphalangeal joints of the fingers or toes 1,2. These are a rare form of superficial musculoskeletal fibromatoses.

Knuckle pads present as bilaterally asymmetrical subcutaneous growths that overlie the dorsal aspect of the finger or toe interphalangeal joint or, less commonly, the metacarpophalangeal joint 2. Knuckle pads are usually skin-colored, firm and painless. However, they can lead to discomfort and large knuckle pads can cause difficulty moving the fingers or toes 3.

Knuckle pads can be genetic and occur more regularly in people with another type of fibromatosis, such as Dupuytren contracture or Peyronie disease 3. Patients most commonly present with knuckle pads as adults, after the age of 30 years 1.

Knuckle pads are a type of superficial musculoskeletal fibromatoses. They are subcutaneous nodules overlying the dorsal aspect of the extensor tendon at the level of the interphalangeal or metacarpophalangeal joint.

The etiology is unknown and is usually considered idiopathic but there are associated with repetitive trauma (e.g. boxing, swimming, carpet laying), and other fibromatoses (e.g. Duputren disease, Peyronine disease, Ledderhose disease) 2,3,5.

Focal proliferation of myofibroblasts and decrease in elastic filaments in the deep, reticular dermis 2.

Soft tissue swelling overlying the dorsal aspect of the interphalangeal joint.

On B-mode, they are seen as subcutaneous hypoechoic nodules with irregular borders. Doppler features include 2:

  • absence of internal flow signals on color or power Doppler

  • peripheral hypervascularisation (rarely)

  • normal appearance of the adjacent joints and tendons is expected

  • T1: low signal

  • T2: intermediate signal

  • T2FS: high signal 4

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Cases and figures

  • Case 1: x-ray
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  • Case 1: ultrasound
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  • Case 2
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