Preliminary Results of Instantaneous Centre of Rotation Change after Thoracic Instrumentation in Adolescent Idiopathic Scoliosis Patients
https://doi.org/10.5704/MOJ.2211.018
- Author:
Asma A
1
;
Onal C
2
;
Eroglu ON
3
;
Berk RH
3
Author Information
1. Department of Orthopaedics, Nemours Children's Hospital Delaware, Wilmington, United States
2. Department of Radiology, Kars Harakani State Hospital, Kars, Turkey
3. Department of Orthopaedics, Dokuz Eylul University, Izmir, Turkey
- Publication Type:Journal Article
- Keywords:
instantaneous centre of rotation, adolescent idiopathic scoliosis, sagittal balance, cervical balance
- From:Malaysian Orthopaedic Journal
2022;16(No.3):120-127
- CountryMalaysia
- Language:English
-
Abstract:
Introduction: The instantaneous centre of rotation (ICR) is
the centre of motion with zero velocity where a rigid body
moves in a particular plane. ICR, as a dynamic measurement,
gives more accurate results in terms of quality and quantity
of the vertebral motions compared to range of motion
(ROM). We aimed to determine the effect of thoracic
instrumentation on cervical movement of adolescent
idiopathic scoliosis (AIS) patients who had undergone
thoracic level instrumentation by measuring pre-operative
and post-operative ICR change in a pilot study
Materials and methods: A total of 25 AIS patients were
included in this study. C4-C5 and C6-C7 segmental ICR
were determined by pre-operative and post-operative
cervical flexion-extension radiographs. In addition, cervical
sagittal parameters and global sagittal parameters were
investigated.
Results: There was no statistically significant change in ICR
location post-operatively in both x and y coordinates at C4-
C5 segment (p: 0.326 and p: 0.946, respectively) and C6-C7
segment (p: 0.209, p: 0.086, respectively). There was a
positive correlation between LCL and C4-C5 ICR y
coordinate (r: 0.481), but not with C6-C7 ICR y coordinate
(r: -0.2, p: 0.398). T5-T12 kyphosis decreased (p: 0.002) and
T1 pelvic angle (0.003), SVA (0.02) and sacral slope (0.049)
increased significantly post-operatively. T1S was correlated
with LCL (r: 0.595, p: 0.002), T5-T12 kyphosis (r: 0.423, p:
0.035), SVA (r: 0.658, p<0.001) and C2-C7 SVA (r: 0.416, p:
0.039).
Conclusion: The ICR for cervical region was not changed
post-operatively in AIS patients with thoracic
instrumentation. There was no relationship found between
the development of post-operative cervical kyphosis or
lordosis and ICR, which represents the quality and quantity
of intervertebral motion. The T1 vertebra plays a key role for
cervical, thoracic, and global parameters interaction.
