Lightning Podiums: Cervical Degenerative - Room 802A

Presented by: S. Shah

Author(s):

M. Bhatia(1), S. Shah(1), W. Beutler(1)

(1) Pinnacle Health, Harrisburg, PA, United States

Abstract

Summary

Background data: Concern remains over the effect of pedicle screw instrumentation on the growth of vertebral body and spinal canal in young children. There was a discrepancy between animal experiments and clinical studies in previous literatures.

Objectives: To investigate whether pedicle screw instrumentation could cause negative effects on the growth of immature spine in children younger than 5 years old.

Methods: Individuals met our criteria were included. Parameters of instrumented vertebrae and adjacent non-instrumented vertebrae were measured on adjusted axial CT images before surgery and at final follow-up. Growth value and growth percentage of each parameter were calculated. Parameters of thoracic vertebrae and lumbar vertebrae were compared, respectively. Statistical analyses were performed.

Results: 13 patients were enrolled. The mean age at surgery was 3.4 (range 2-5) years old with an average follow-up of 7.2 (range 5-11) years. Osteotomy and instrumentation with pedicle screws were performed. Total 69 segments were measured, including 43 instrumented vertebrae and 26 adjacent non-instrumented vertebrae. Significant increases of all parameters were noted at the final follow-up. Growth value and growth percentage of PL, CAP and AREA increased significantly, and those of VAP decreased significantly in IV group compared to NIV group. Similar results were noted in lumbar region. Shape-change phenomenon was found in NIV group and not apparent in IV group.

Conclusion: Pedicle screw instrumentation may mainly slow down the growth of vertebral body, indirectly speed up the growth of spinal canal, and hinder the shape-change phenomenon of lumbar spinal canal. But the negative effects were quite tiny and significant developments did occur in instrumented vertebrae. So pedicle screw instrumentation was reliable and trustworthy in children younger than 5 years old.

Abstract

Objective: To determine if the side of approach in anterior cervical discectomy and fusion is associated with increased risk of recurrent laryngeal nerve injury. Summary of

Background: Recurrent laryngeal nerve (RLN) injury is a well known but potentially devastating injury after anterior cervical discectomy and fusion (ACDF) procedures. Although RLN injury is most often transient in nature, there is the associated clinical consequences of dysphonia, impaired high-pitch phonation, impaired cough reflex, airway obstruction, hoarseness, vocal fatigue, and in some cases, tracheotomy. The incidence of RLN injury in the literature ranges from 0.07% to 5.1% but there is a lack of standardized definitions, and the likelihood of an underreported value. There are numerous papers reviewing the complication, but there is no large-scale, randomized prospective single surgeon, single study investigating the correlation of laterality of approach to the risk of recurrent laryngeal nerve injury.

Methods: A fellowship trained spine surgeon prospectively performed ACDFs between the years of 2003-2012. Side of approach was chosen based on the contralateral sided symptoms. Patients were monitored postoperatively for development of recurrent laryngeal nerve palsy symptoms and other complications. Patients found to have signs of recurrent laryngeal nerve injury were sent to ENT for evaluation and monitored for recovery.

Results: 411 ACDFs were performed during the 10-year period. 190 right sided and 221 left sided procedures were done. The incidence of recurrent laryngeal nerve injury was 14 (13 primary procedures and 1 revision). 7 nerve injuries were in a right sided approach and 7 were in a left sided approach. The risk of injury was 3.18% in a left sided approach and 3.70% in a right sided approach with a p-value of 0.7723 indicating that there is no significant difference between the sides of the approach.

Discussion: Our study's analysis showed that there is no significant difference in RLN injury between the sides of approach. This is similar to an analysis of four spine surgeons at an academic center reported in 2001 which evaluated 328 ACDFs from 1989 to 1999. There was no association between the side of approach and the incidence of RLN injury. Multiple retrospective and prospective trials also failed to show an increased risk. Although there is usually spontaneous resolution of hoarseness, it is important to remember that patients with a vocal cord paresis may be asymptomatic, and patients with symptomatic dysphonia may have no vocal cord paresis. Our data represents the first randomized prospective single surgeon study of risk of symptomatic RLN injury from side of approach. Our findings note laterality of approach for ACDF has no bearing on the incidence of injury.

Conclusion: In a single surgeon randomized prospective study there was no significant difference was noted between the side of approach and the risk of recurrent laryngeal nerve palsy.