Acro-osteolysis

Acro-osteolysis (plural: acro-osteolyses), also known as phalangeal osteolysis, refers to resorption of the distal phalanx. The terminal tuft is most commonly affected. It is associated with a heterogeneous group of pathological entities, some of which can be remembered by the mnemonic PINCH FO.

Terminology

There are two main radiological variants of acro-osteolysis ¹⁷:

• longitudinal type: terminal tuft resorption

• transverse type: linear bone resorption of the midshaft of the distal phalanx: band acro-osteolysis

These variants may coexist ¹⁷.

Pathology

Multiple digits

Terminal tuft resorption

• scleroderma ⁴

• Raynaud disease

• psoriatic arthritis

• thermal injury 

  • extreme cold: frostbite

  • extreme heat: burns, electricity

• trauma

• hyperparathyroidism

• epidermolysis bullosa

• porphyria

• drugs

  • phenytoin (occurs in infants of epileptic mothers treated with phenytoin) ⁷

  • ergot poisoning/abuse

• insensitivity to pain, e.g. leprosy, congenital insensitivity to pain

• juvenile idiopathic arthritis

• dermatomyositis

• vascular occlusion ⁵

• reactive arthritis ⁶

• pityriasis rubra pilaris ⁸

• pachydermoperiostosis ⁹

• sarcoidosis ¹⁶

Midshaft resorption (band acro-osteolysis)

• polyvinyl chloride exposure ¹⁰

• primary acro-osteolysis: Hajdu-Cheney syndrome

• hyperparathyroidism (also causes terminal tuft resorption)

• scleroderma ¹¹ (also causes terminal tuft resorption)

• idiopathic non-familial acro-osteolysis ¹⁵

• pyknodysostosis ^13,14 (also causes terminal tuft hypoplasia)

• biomechanical in guitar players ¹¹

Single digit 

• epidermal inclusion cyst ³

• glomus tumor of digit ³