Synonyms of pseudarthrosis are false joint , sham joint and pseudo-joint . If the fracture healing is not completed within four to six months after the trauma , it is referred to as delayed fracture healing . If the healing takes longer than six months, one speaks of a pseudarthrosis. Bones affected by pseudarthrosis are often shaft fractures of long tubular bones (lower leg, thigh, upper arm and ulna with radius) as well as the navicular bone .
A distinction is made between two special forms:
The vital pseudarthrosis shows sufficient vascularization , but the fracture is unstable. On the other hand, avital pseudarthrosis shows, in addition to instability, an inadequate blood circulation, often also infected areas or sequesters .
The following causes are considered mechanical factors for the development of pseudarthrosis:
- Interposition of soft tissues into the fracture gap
- low compression on the fracture gap, e.g. B. by a dynamic compression plate
- insufficient immobilization or mobilization too early.
Favoring factors are:
- insufficient blood supply
- Infectious disease
- Tissue loss
- Systemic diseases such as diabetes mellitus or arterial occlusive diseases .
In the case of a "hypertrophic" vital pseudarthrosis, the characteristics of which are an adequate blood supply, a wide zone of fibrous cartilage formation and a high degree of ossification , this therapy is indicated:
- Improvement of the mechanical framework conditions (e.g. through plate osteosynthesis, intramedullary nail or ring fixator )
- Stabilization by means of osteosynthesis , removal of non-vital and possibly infected bone areas, reconstruction of the bone defect through spongiosaplasty or callus distraction .
- As an alternative or in addition to spongiosaplasty, treatment with bone morphogenetic protein , in particular BMP2 and BMP7, is also possible.
- George Chapchal (Ed.): Pseudarthroses and Their Treatment. 8th international symposium on top problems in orthopedic surgery . Thieme, Stuttgart 1983, ISBN 3-13-562801-9 .
- Rüdiger Döhler : Pseudarthrosis. In: ders. (Ed.): Lexicon Orthopädische Chirurgie . Berlin 2003, ISBN 3-540-41317-0 , pp. 176-180. GoogleBooks
- Uwe Günter: The pseudarthrosis after ankle arthrodesis . Dissertation at the Humboldt University in Berlin, 2000.
- pseudarthrosis . In: Peter Reuter: Springer Lexicon Medicine. Springer, Berlin a. a. 2004, ISBN 3-540-20412-1 .