Study design: This is a retrospective observational case series.
Objectives: To determine whether or not trunk deformity correction is achieved and maintained using the surgical techniques described.
Summary of background data: Transverse plane trunk deformity correction and correction maintenance have been questioned.
Methods: The study group of 44 patients (40 female, 4 male) had a mean age of 16.1 years (range 10-38 years). Thirty-three had thoracic and 11 had a double curve pattern with a mean largest preoperative curve of 65 degrees. All had preoperative and follow-up at a median of 25 months (range 20-69 months); surface topography exposures quantified for both the coronal plane, as determined by the Posterior Trunk Symmetry Index, and transverse plane, as determined by the Suzuki Hump Sum, asymmetry. Thirty-four also had early postoperative studies. Change following surgery was determined by the signed rank test, with P < 0.01 being significant.
Results: Preoperative to latest follow-up largest Cobb angles had improved from a mean of 65 degrees to 23 degrees (65%, P < 0.0001), Posterior Trunk Symmetry Index from 55 to 20 (64%) (P < 0.0001), and Suzuki Hump Sum from 20 to 12 (40%) (P < 0.0001). Posterior Trunk Symmetry Index improved during the follow-up from 26 to 20 (23%) (P = 0.007). Neither Cobb nor Suzuki Hump Sum further improved or deteriorated during follow-up.
Conclusion: These findings validate the concepts of torsional posterior spinal instrumentation and wide-thick arthrodesis to provide significant and lasting coronal and transverse plane trunk deformity correction.