Comparison of two techniques in hemivertebra resection: transpedicular eggshell osteotomy versus standard anterior-posterior approach

Abstract

Hemivertebrae are the most frequent cause of congenital scoliosis. They have growth potential similar to normal vertebra, creating wedge-shaped deformity that progresses during further spinal growth. This study aims to compare the interventions for hemivertebrae resections in congenital scoliosis by posterior transpedicular eggshell osteotomy approach only and with combined anterior and posterior approach. Ten patients who underwent hemivertebra resection between 1995 and 2002 were evaluated by retrospective charts and radiographic views. Mean follow-up time was 32 months (range 12-48). Except one patient, all were female and mean age at surgery was 7 years (range 3-13). Transpedicular eggshell osteotomy was performed in five patients (group I) and by combined anterior and posterior approach in five patients (group II). All patients had a single non-incarcerated hemivertebra and the locations of the hemivertebra were Th7, Th8, Th11, Th12, L2 in group I and Th7, Th10, L1, L4, L5 in group II. The average operation time was 3 h in group I and 6 h in group II (P < 0.05). The number of instrumented vertebrae was 4 for group I and 6 for group II. The mean blood loss during the operation for groups I and II was 354 and 500 cc, respectively (P < 0.05). The mean Cobb angle was measured as 37 degrees before surgery, 18 degrees after surgery and 21 degrees at the latest follow-up for group I; 32 degrees, 14 degrees and 17 degrees for group II. The correction ratio was 51% in group I and 56% (P > 0.05). The loss of correction was 8% in group I and 9% in group II (P > 0.05). No intra-operative complications were noted and no implant failure was verified at the final radiographic evaluations. Transpedicular eggshell osteotomy is a technique that should be considered for older patients who have congenital scoliosis with multiplanar spinal abnormalities. It is a technically demanding procedure that provides an effective correction in selected patients.