Progression of low back and lower extremity pain in a cohort of patients with achondroplasia

Object. The aim of this study was to assess the natural history of pain associated with spinal stenosis in individuals with achondroplasia and to characterize pain patterns and associated functional and psychological effects. Methods. The authors measured pain severity, spatial distribution of pain, functional disability, psychological distress, physical symptoms other than pain, and healthcare utilization in 181 individuals with achondroplasia. They also assessed low back and/or lower extremity pain at the initial visit and 1-year follow-up via self-rated patient questionnaires, calculated composite scores from responses via component analyses, and used repeated measures linear regression analyses for score changes (significance, p ≤ 0.05). Results. At the follow-up, back pain severity was unchanged. Patients reported significant progression of pain toward involvement of the lower extremities and significant increases in lower extremity pain severity overall. There were also significant increases in healthcare utilization overall. Compared with patients with back pain only, those with back pain and proximal or distal leg pain had higher self-rated pain severity; higher functional disability; and more bowel and bladder dysfunction symptoms, sleep disturbances, extremity numbness, and psychological distress. Conclusions. Individuals with achondroplasia and symptomatic spinal stenosis often experience back pain, which may progress to lower extremity pain and debilitating consequences. A more thorough understanding of the progression of spatial pain characteristics and pain severity may aid clinical decision making regarding the optimal timing for intervention.