Abstract
Introduction/Aim
In rigid Sagittal and Coronal deformities of the spine Pedicle Subtraction Osteotomies (PSO) is preferred to achieve maximal correction. We describe successful Asymmetrical Pedicle Subtraction Osteotomies (APSO) performed on patients with symptomatic coronal imbalance.
Methods/Results
Case 1: 28yr old female with VATER syndrome with 25° coronal imbalance to her left with past h/o fusion from L3 – S1 for L5 hemi-vertebra. After APSO at L3 coronal imbalance was reduced to 0°.
Case 2: 49yr old male with post-traumatic coronal deformity of 35° at T6 and paraplegia affecting his sitting balance and respiratory function. Following APSO at T12 imbalance was reduced to 5°.
Osteotomy Technique
After insertion of pedicle screws for the stabilisation, laminectomy of the proposed level of osteotomy was performed. Next, dissection lateral to the pedicle and vertebral body was performed bluntly with mastoids to reach the front of the anterior cortex and confirmed with fluoroscopy. Using osteotomes, curettes and Kerrison oblique osteotomy from the lateral cortex to reach opposite cortex was performed above & below the pedicle under imaging. The facets were resected at this level to facilitate mobility of the osteotomy site. The osteotomy site was closed after insertion of extra hard rods.
Conclusion
Satisfactory correction of coronal deformity can be achieved with asymmetrical pedicle subtraction osteotomy to improve cosmesis and also the sitting and standing balance. In contrast to Sagittal Osteotomies, blunt dissection to the anterior cortex is necessary in coronal Osteotomies to allow resection of anterior cortical bone for closure of the wedge.
