Hybrid Posterior Instrumentation and Mini-Open Anterior Release for Treatment of Adolescent Idiopathic Scoliosis: A Retrospective Analysis
Objective: A retrospective analysis of the role of hybrid instrumentation, mini-open anterior release in the treatment of adolescent idiopathic scoliosis.
Methods: Medical records and imaging of 43 patients operated between January 2008 to June 2014 were retrospectively analyzed. Subgroup analysis was done for patients managed with mini-open anterior release+ posterior instrumentation[APSF](13 patients) vs. all posterior approach [PSF](30 patients). Hybrid instrumentation was used involving the use of hooks and sublaminar wires in conjunction with pedicle screws. A mini open thoracotomy (<10 cm incision) was used for anterior release. The free-hand technique was used to insert all the pedicle screws. Stagnara wake up test was used after correction manoeuvers. Appearance scores were collected before and after the surgery.
Results: The mean age of operated cases was 15.2 (range 10-28) years, and majority cases were females (86.05%). The average follow-up time was 46.86 months. Lenke 1 was the most common curve pattern [74.42%]. Significant correction was achieved and maintained at the end of the follow-up period for all the curve patterns [PT 66.67%, MT 75.20%, DL/L – 70.83%]. The sagittal plane alignment was maintained in all but one patient. Mean [81.25° vs. 49.16°] and bending [66.89° vs. 32°] Cobb angles were significantly higher in the APSF group. Improvement in the appearance scores was significant for both the groups [APSF - 25 vs. 10.78, PSF - 18.9 vs. 9.03]. Two of the APSF patients had prolonged ICU stay. Two patients required secondary suturing for wound dehiscence. One case had chylothorax, which was medically managed. One patient required revision surgery for hook pull-out after 34 months of index surgery. There were no neurological deficits, vascular or visceral injuries.
Conclusion: Adolescent idiopathic scoliosis represents a different set of challenges in developing nations with limited resources. Hybrid instrumentation with the use of sublaminar wires is still an effective and valid strategy to reduce the cost of spinal deformity surgeries. A mini-open anterior release, along with the use of posterior hybrid instrumentation, helps achieve optimal coronal and sagittal correction, especially in bigger and stiffer curves, compared to all posterior hybrid constructs. A decision tree is provided to guide the treatment selection for the adolescent idiopathic scoliosis cases.
Keywords: Adolescent idiopathic scoliosis, hybrid instrumentation, anterior release, posterior approach, spinal deformity, pedicle screws, sublaminar wires
Citation: Dhillon CS, Chhasatia N, Dwivedi R, Loya V. “Hybrid Posterior Instrumentation and Mini-Open Anterior Release for Treatment of Adolescent Idiopathic Scoliosis: A Retrospective Analysis”. SVOA Orthopaedics 1:1 (2021) Pages 15-23.