Choi IIIB sequelae of septic hip: Etiologically different entities clubbed together?

BACKGROUND

Choi IIIB sequela (pseudarthrosis of femoral neck) is an uncommon complication of septic hip. Only few cases are reported in literature and experience with the entity is limited. Variable pseudarthrosis behaviour and treatment outcomes are reported questioning the mechanical etiology for Choi III sequela.

METHODS

We briefly analysed the relevant literature and propose two different pathomechanism for the entity. Three illustrative cases in support of proposed etiology are presented.

RESULTS

There seems to be two distinct mechanisms of pseudarthrosis formation in Choi IIIB. The originally described mechanism is the articulating head getting dissociated from proximal femur due to a mechanical cause. The second proposed mechanism is the damage of physis and adjoining metaphysis by the septic inflammatory process (Choi II type sequela).

CONCLUSIONS

It is important to understand the possible etiologies in Choi IIIB pseudarthrosis as the treatment planning and outcomes may vary. It will also help in prognostication.