Factors associated with increased back pain in primary thoracic adolescent idiopathic scoliosis 10 years after surgery.

PURPOSE

To identify the prevalence and predictors of nonspecific back pain in primary thoracic adolescent idiopathic scoliosis (AIS) patients at 10 years after surgery.

METHODS

This was a case-control multi-center study. A query of patients who underwent surgical correction of major thoracic AIS between 1997 and 2007 with 10-year follow-up was reviewed. SRS-22 pain scores at 10 years were classified as below normal (≤ 2 standard deviations below average for controls of similar age/sex from published literature) or within/above the control range.

RESULTS

One hundred and seventy-one patients with an average of 10.5 ± 0.8-years follow-up were included. Average age at surgery was 14 ± 2 years. The rate of pain was 23% for males and 11% for females (p = 0.08). Differences in age, 10-year SRS mental health score, and radiographic measures were noted. Of 12 patients who underwent revision surgery, 42% reported below normal pain scores versus 11% in cases without revision (p = 0.012). Classification and regression tree (CART) analysis identified 10-year thoracic curve magnitude and 10-year mental health scores as significant predictors. Thoracic Cobb of ≤ 26° at 10 years was associated with a 7% rate of below normal pain scores compared to 27.5% when the curve was > 26° (OR = 4.8, p < 0.05). Of those with a curve ≤ 26°, no patients had abnormal pain if the SRS mental health score was > 4.2 and 15% had more pain than normal if mental health score was ≤ 4.2 (OR 23, p < 0.05).

CONCLUSION

Increased primary thoracic curve magnitude (> 26°) at 10 years was the primary predictor of increased pain. For patients with less coronal deformity (< 26°), a poor mental health score was associated with an increased rate of pain. Male gender and revision surgery may also play a role in increased pain, however, the overall frequency of these variables were low.

LEVEL OF EVIDENCE

Level 3.