Abstract
Aim
To evaluate the influence of arthrodiatasis in the natural history of the stages of the disease radiologically and also the timing of arthrodiatasis.
Materials and methods
44 patients with Perthes' disease that had articulated hip distraction were radiologically evaluated. We assessed these based on Joseph's modified Elizabethtown classification before, during and soon after distraction. Other parameters used were the application of common radiological grading systems and other features.
Results
13 were operated before Stage 2b or before late fragmentation. Of these 10 skipped one or more stage/s during distraction or within one month from distractor removal. This phenomenon was not observed in any of the 28 patients who had the distractor put on during late fragmentation or later. However, these 28 patients had some enhancement in reossification. 3 patients had adolescent onset with destructive type in 2 and segmental collapse type in 1 where stages are not clearly seen. We also noticed that the late onset presenters with subluxation did show improvement of their subluxation and contractures. Application of the Herring and Salter–Thompson classifications could not be universally used as they were in different stages of the disease and due to incomplete frog leg views.
Conclusions
Timing of surgery in the early stages of the disease appears to affect the natural evolution of the disease process by skipping the stage of fragmentation. This corroborates with Joseph's paper on osteotomies. This is an early observational study and based on this hypothesis a prospective study with clinical outcomes will follow.
