Morbus Thiemann
Thiemann disease (also called familial osteoarthropathy of the fingers or osteonecrosis of the base of phalanx) is a non-inflammatory disorder of unknown etiology and refers to osteonecrosis of the epiphyses of the phalanges which leads to deformity of the fingers.
Epidemiology
Thiemann disease is a rare form of avascular necrosis which involves proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints in the second decade of life. The base of the proximal phalanges of the index and middle fingers are usually affected.
Cases generally arise in children and young adults (<25 years old) .
Thiemann disease is usually familial (with an autosomal dominant inheritance pattern), usually with complete penetrance, and a balanced male:female case distribution . Sporadic cases have also been reported and are three times as common in males .
Clinical presentation
Clinical presentation and radiologic appearance of Thiemann disease correspond closely with those of Mauclaire disease (osteonecrosis of the metacarpal heads).
An initial painless swelling of the proximal interphalangeal joints, with eventual development of pain and deformity is the typical clinical presentation.
Occasionally the toes, primarily the big toes, and the first tarsometatarsal (TMT) joints are also affected, in which case it may be called osteochondritis ossis metacarpi et metatarsi .
Blood tests are normal - including erythrocyte sedimentation rate - with no elevation in the level of acute phase proteins, e.g. C-reactive protein.
Pathology
Histopathology demonstrates an aseptic osteonecrosis with unremarkable vasculature, and lacking inflammatory changes .
Radiographic features
Irregularity of the epiphyses of the phalanges is seen. The bones appear broadened, sclerotic and fragmented. Joint space narrowing may be seen later.
Treatment and prognosis
Treatment is usually conservative, although in severe disease arthrodeses or arthroplasties may be needed.
History and etymology
The condition was first reported by a German physician H Thiemann in 1909 .