Abstract
Genetic defects causing dwarfism occur in approximately 1 in 10 000 live births. There are over 200 types. Another frequent cause of short stature is juvenile rheumatoid arthritis. Most types of dwarfism result in arthrosis of major joints resulting in significant disability. Hip replacement can offer significant improvement in quality of life, but there are inherent difficulties due to size and anatomic variations.
Short stature of less than 4 feet 10 inches was defined as dwarfism. Eight patients meeting this criterion underwent either primary or revision total hip replacement, with six being bilateral, resulting in a total of 14 hips for study (six primaries and eight revisions). The diagnoses were: two JRA, two Mucolipdosis III, one Dyastrophic Dwarfism, one Spondyloepiphyseal Dysplasia, one Thalasemia, and one Congenital Rickets. In eight hips a CT-based custom cementless femoral component was used. Average follow-up was nine years (2 – 14).
The average Total Harris Hip Score improved from 35 pre-operatively to 66 at last follow-up, with the average Harris Pain Score increasing from 10 to 31 (out of a maximum of 44). Of the six primary hips, two hips in the same patient have been revised for combined acetabular and femoral loosening. Of the eight revision hips, there have been three re-operations: one re-revised for acetabular loosening, one re-revised for late hematogenous infection and one head/liner change for recurrent dislocations.
Hip replacement in dwarfs presents a complex technical challenge, but can result in significant improvement in pain, function and quality of life. CT-base custom femoral components are recommended.
The abstracts were prepared by Nico Verdoschot. Correspondence should be addressed to him at Orthopaedic Research Laboratory, Universitair Medisch Centrum, Orthopaedie / CSS1, Huispost 800, Postbus 9101, 6500 HB Nijmegen, Th. Craanenlaan 7, 6525 GH Nijmegen, The Netherlands.
