At Mean 30-Year Follow-Up, Cervical Spine Disease Is Common and Associated with Thoracic Hypokyphosis after Pediatric Treatment of Adolescent Idiopathic Scoliosis

Abstract

Patients with adolescent idiopathic scoliosis (AIS) often have reduced sagittal thoracic kyphosis (hypokyphosis) and cervical lordosis causing an uneven distribution of physiologic load. However, the long-term consequences of hypokyphosis in AIS patients have not been previously documented. To evaluate whether uneven load distribution leads to future complications in patients with AIS, we conducted a retrospective chart review and subsequently surveyed 180 patients treated for idiopathic scoliosis between 1975 and 1992. These patients all had a minimum follow-up time of 20 years since their treatment. We observed a ten-fold increase in the incidence of anterior cervical discectomy and fusion (ACDF) compared to reported rates in the non-pathologic population. Out of the 180 patients, 33 patients met the criteria and returned for follow-up radiographs. This population demonstrated a statistically significant increased rate of cervical osteoarthritis and disc degeneration. Overall, our study suggests that hypokyphosis in patients with AIS presents with increased rates of cervical spine degeneration and dysfunction, suggesting that these patients may require additional follow-up and treatment.

Increasing Cervical Kyphosis Correlates With Cervical Degenerative Disk Disease in Patients With Adolescent Idiopathic Scoliosis

“…Young and colleagues recently evaluated the long-term impact of cervical spine disease in AIS patients treated between 1975 and 1992 and found a 10-fold increase in the need for anterior cervical discectomy and fusion compared with the general population. In the same study, those with available radiographs showed a 58% rate of moderate or severe cervical osteoarthritis 16 . In this study, we showed that over 50% of patients with AIS may have evidence of cervical DDD before surgical intervention.…”

“…In the same study, those with available radiographs showed a 58% rate of moderate or severe cervical osteoarthritis. 16 In this study, we showed that over 50% of patients with AIS may have evidence of cervical DDD before surgical intervention. The mean age of patients in this study was 14.1 years (SD = 2.5 years), suggesting an early onset of degenerative changes in the intervertebral disks and raising concerns for long-term outcomes even with treatment to correct spinal deformities.…”

Patient and surgical predictors of 3D correction in posterior spinal fusion: a systematic review

“…Le Navéaux et al [18] Normokyphotic and hypokyphotic Intra-op correction maneuvers resulted in a significant flattening of concave rods (21° ± 9°) after implantation, such that the pre-insertion concave rod curvature was not predictive of postoperative thoracic kyphosis. In addition, the planes of maximum curvature of both rods were deviated from the sagittal plane after surgical instrumentation.…”

“…Generations of surgical procedures have aimed at correcting the frontal curve and truncal deformity while maintaining spinopelvic alignment [8][9][10][11][12][13][14][15][16]. As 40-46% of all AIS patients are hypokyphotic, special attention should be paid to restoring sagittal balance in these patients, with studies supporting that failure to restore thoracic kyphosis (TK) may predispose to proximal or distal junctional kyphosis, as well as late complications predisposing to future decompensation [17][18][19][20][21]. While pedicle-screw systems have been shown to demonstrate efficacious correction in the frontal and axial planes by the placement of powerful anchors, they have been shown to cause flattening of the sagittal spine [22][23][24].…”

The Risk and Benefits of Various Innovations in Fusion and Fusionless Surgery for AIS

“…Persistent thoracic hypokyphosis may drive the cervical spine into further kyphotic compensation, with potentially negative effects on the unfused cervical discs. Interestingly, Young et al surveyed 180 AIS patients treated between 1975 and 1992 by Milwaukee braces comprising Harrington rods, and 33 had lateral radiographs available at adolescent age [ 2 ]. At an average follow-up age of 43 years, 4 AIS patients had undergone cervical surgery for disc disease (2.2%), compared to 0.03–0.16% of the general population.…”