Comparison of Scheuermann’s Kyphosis Correction by Combined Anterior-Posterior Fusion Versus Posterior-Only Procedure
Introduction: Conventional treatment of rigid kyphosis in the Scheuermann’s disease in young patients includes a preliminary anterior release and fusion. However, controversy remains regarding the outcome of the two procedures (ASF/PSF vs. PSF-only procedure). The purpose of the study was evaluation of kyphosis correction, correction loss, sagittal balance, and clinical parameters such as Oswestry disability index (ODI) and scoliosis research society questionnaire-30 (SRS-30) in the two groups of combined anterior spine fusion- posterior spine fusion (ASF/PSF) surgery and PSF-only procedure
Materials and Methods: In this prospective clinical and radiological review, thirty patients who had undergone surgery for their Scheuermann’s kyphosis were evaluated.
Group A:anteroposterior technique (n:16) and group B:posterior-only procedure(n:14)were followed for at least 2 years (average:57.6 months).The two groups were well matched for the following four criteria; average age(20.9±5.3 vs. 19.3±2.7,P=0.304),flexibility status (87.5% rigid type vs. 85.7%,P=0.65),posterior fusion levels (11.9 vs. 12.5,P=0.1), and preoperative Cobb’s kyphosis(83.7º±8.1 vs. 81.9º±9.4, P=0.59). Fixation in group A was achieved mainly by open thoracotomy and fusion followed by a hooks or hybrid hook/screw instrumentation. Posterior fixation in group B was performed using segmental thoracic pedicle screw construct and posterior shortening osteotomy (Ponte-type). Clinical and radiographic parameters were evaluated before and after surgery and at the final follow up.
Results: In group A,primary thoracic Cobb’s kyphosis, immediate post-operative kyphosis, and final follow up kyphosis were 83.7º, 41.4º,and 43º respectively, (P=0.001) with a 50.5% correction rate and 1.6º±2.4 correction loss .In group B, the values obtained for the corresponding parameters were 81.9º, 40.1º,and 43.2º respectively, (P≤ 0.001) with a correction rate of 51% and correction loss of 3.1º±2.5. The two groups were not significantly different with regard to the correction rate (P=0.91) and correction loss (P=0.12).SRS-30 and ODI scores in group A were averaged 68.5 and 21.3 preoperatively and128.7 and 6.25 at the final follow up, respectively. In group B, the corresponding values were 64and 23.2 preoperatively and 133.5 and 5.8 at the final follow up, respectively.
Comparison of the two groups with regard to the score obtained from SRS-30 (P=0.21), ODI (P=0.93), and sagittal balance outcomes(P=0.45) showed no significant difference. The rate of complications observed in group A was 37.5% (6/16), while it was 7.1% for group B (1/14), which shows a higher complication rate in group A (P=0.03).
Conclusion: Preliminary anterior release and fusion is not recommended when possibility of deformity correction with a posterior column Ponte osteotomy and pedicle screw construct is possible..