Abstract
There are limited data on scoliosis in cystic fibrosis (CF), and the two most recent studies came to opposite conclusions. Reported prevalence ranges from 2% (within the normal range for the general population) to 15.5%. We felt that a recent study under-estimated the prevalence due to a very young population (mean age 10.9 years), since scoliosis develops most commonly in adolescents. We hypothesised that scoliosis is more prevalent in adolescents with CF compared to the general population. The aim of our study was to determine the incidence of scoliosis in adolescents with CF followed to and beyond skeletal maturity and describe the type of spinal deformity. We included all patients in our CF clinic aged >10 years, and those who have transitioned to adult services in the last 10 years. Patients with a co-existent neuromuscular condition were excluded.
We conducted a retrospective observational study. Most recent chest radiographs at end of spinal growth, or those taken at transition to adult services, were reviewed by a Consultant Radiologist and a Consultant Spine Surgeon. Scoliosis was defined as a Cobb angle of >10° in the coronal plane. Demographics and characteristics of the curves were recorded.
Our cohort included 143 CF patients (48% male) with a mean age at the time of chest radiograph of 18 years (range 15–22 years). 16 (6 male) subjects were noted to have scoliosis with a mean (range) Cobb angle of 14° (10–38°) giving a prevalence of 11%. 13 were single thoracic curves, 2 double and 1 triple. The majority were non-progressive short mid-thoracic curves, convex to the right. 5 curves were progressive, only one of which was significant and required bracing to the end of growth but no surgical treatment.
We found a prevalence of scoliosis in our adolescent CF population that is significantly greater than the general population. Only one curve was significant and progressive requiring bracing, the remainder being minor and non-progressive. A strength of our study is that all patients had achieved skeletal maturity at the time of latest X-ray and, therefore, development or further progression of scoliosis is unlikely. The negative effect of scoliosis on lung function is well-documented. With the progressive nature of CF lung disease, scoliosis may have further deleterious effects. Bone disease is increasingly recognised in CF patients, with osteopenia and osteoporosis occurring earlier and more frequently than in the general population (38% & 24% respectively in 18–32 year old CF patients). To date, studies have failed to show a correlation between scoliosis, lung function and bone mineral density. The paradigm of a radiologically significant (Cobb angle >10°) versus a clinically important scoliosis remains.
