Abstract
Although achondroplasia has been cited as the most common form of rhizomelic dwarfism, no report in the literature has given the data on the ratio of their upper and lower limb segments. We performed a paired study of 91achondroplasia patients with age and gender matched normal control group. Their upper and lower extremity radiographs were evaluated, and their radio-humeral and tibia-femoral ratios were compared. The ratios were compared using the Wilcoxon rank sum test. A p value of <0.05 was considered significant. The mean age of the patients was 15.8 years (95% confidence interval (CI), 13.1–18.6), and there were 45 males and 46 females. The radio-humeral ratio for the upper extremity of achondroplasia patients was 0.76 (95% CI, 0.75–0.76) which was significantly different from the normal control group of 0.79 (95% CI, 0.77–0.80) (p=0.001). The tibio-femoral ratio of the achondroplasia patients was 0.79 (95% CI, 0.78–0.79), which was not significantly different from the normal control group of 0.78 (95% CI, 0.77–0.79) (p=0.346). Rhizomelia is the predominant form of dwarfism in upper extremity, but not in lower extremity in achondroplasia. The functional deficits from these patients seem to come from the generalized limb shortness, and not specifically from rhizomelia.
