Background: Diastrophic dysplasia results in severe disproportionate
short stature, generalized joint deformities, and early osteoarthritis. The
knee joint often has an abnormal valgus position and is unstable, and
degeneration of all joint compartments occurs, even during growth. The purpose
of our study was to evaluate the clinical and radiographic results of total
knee arthroplasty in a series of patients with diastrophic dysplasia.
Methods: Between February 1992 and March 2000, twenty-one primary
total knee arthroplasties were performed on fourteen consecutive patients with
severe osteoarthritis due to diastrophic dysplasia. The patients were followed
prospectively with clinical examinations, determination of the Hungerford knee
scores, and radiographs. Preoperatively, ten knees had chronic dislocation of
the patella. The mean duration of follow-up was 3.4 years.
Results: The mean Hungerford knee pain and total scores improved
from 5.8 points and 46 points preoperatively to 50 points and 83 points,
respectively, at the final follow-up examination (p < 0.001 for both
comparisons). Two knees required a distal femoral corrective osteotomy because
of metaphyseal angulation. None of the total knee arthroplasties had to be
revised during the follow-up period. Six complications were recorded.
Conclusions: Total knee arthroplasty substantially improved the
function of patients with diastrophic dysplasia. Additional peripatellar
procedures were commonly needed, and complications were frequent.
Level of Evidence: Therapeutic study, Level IV (case
series [no, or historical, control group]). See Instructions to Authors for a
complete description of levels of evidence.