Abstract
Background:
Pediatric patients with inflammatory conditions often present with single or multifocal joint pain. Assessment of these patients at our institution revealed a possible association between femoroacetabular impingement (FAI) and inflammatory comorbidities. The purpose of this study was to investigate the prevalence and unique characteristic morphology of FAI in pediatric patients with inflammatory comorbidities.
Methodology:
A retrospective review was conducted on a consecutive series of 105 patients diagnosed with FAI in our institution’s adolescent hip clinic from January 2016 to March 2018. Patients with an inflammatory comorbidity were identified. Femoral head-neck junction morphology was assessed qualitatively and with standard radiographic measures for FAI.
Results:
Seven patients (6.7% of diagnosed patients), with eight symptomatic hips, were found to have FAI and an inflammatory comorbidity. These diagnoses included Crohn’s disease, Celiac disease, juvenile idiopathic arthritis, Type 1 diabetes mellitus and hypothyroidism. All seven patients had cam deformities. Qualitative assessment revealed that most patients had a characteristic head-neck morphology that was unique to this subset of patients, with a prominent and “sharp-edged” bump at the head-neck junction (See Figure 1). Radiographic analysis of the symptomatic hips revealed a mean alpha angle of 81.3o (±8.7 o), mean LCEA of 33.1o (±8.4 o) and mean femoral offset of 0.07 (±0.05). There was no significant difference in the radiographic measurements between symptomatic and asymptomatic hips in these patients.
Conclusion:
This is the first study to identify an association between FAI and inflammatory comorbidities in pediatric patients, with a prevalence of 6.7% at our institution. Given the relative rarity of inflammatory comorbidities in the general pediatric patient, this represents an unexpectedly high association. These patients presented with a unique head-neck morphology characterized by a more prominent and “sharp-edged” cam lesion than the typical morphology seen in patients without an inflammatory comorbidity. This study raises questions regarding the possible role of physeal inflammation in the development of cam deformities and indicates a need for further studies investigating the relationship between systemic inflammatory disorders and FAI.
The characteristic prominent, sharp-edged cam deformity observed in patients with inflammatory comorbidities.