Impact of Metal Density on Deformity Correction for Adolescent Idiopathic Scoliosis

Impact of Metal Density on Deformity Correction in Posterior Fusions for Adolescent Idiopathic Scoliosis

A retrospective analysis to ascertain the correlation between metal density and deformity correction among individuals with adolescent idiopathic scoliosis.

Study Overview

• Status: Completed
• Conditions: Adolescent Idiopathic Scoliosis
• Intervention / Treatment: Other: Posterior spinal instrumentation

Detailed Description

Posterior spinal fusion with pedicle screws has become the "gold standard" for the management of adolescent idiopathic scoliosis (AIS). Pedicle screws provide three column fixation through the strongest part of vertebra thereby enhancing surgeon's ability to do a 3-dimensional deformity correction. The higher pullout strength results in less long-term loss of correction, shorter fusions resulting in preservation of motion segments, lower pseudarthrosis rates and lower implant failures compared with these alternative posterior instrumentation systems. However, studies are contradictoryregarding the effect of metal density on coronaland sagittal curve corrections. Multiple factors including curve flexibility, instrumentation and rod types, reduction strategies and curve types, affect outcomes. Given this, intraoperative decisions regarding the number of anchorage points remain difficult, with considerable inter-surgeon variability.

The rationale for using a high implant density constructs is to obtain more rigid fixation and to limit potential stress concentration at any one screw. Furthermore, health-related quality of life instruments such as the SRS 22, 24, or 30 seem to show little correlation with curve correction. The placement of every additional pedicle screw is associated with increased operative time, risk of neurological deterioration and increased implant cost. If implant density can be lowered without compromising clinical results, reducing the number of screws may improve the efficiency and cost effectiveness of scoliosis surgery. Several authors have demonstrated successful results with low-density instrumentation for the treatment of scoliosis. The purpose of this retrospective review is to describe the demographics of our patient population and to ascertain correlation between metal density and correction achieved.

• Study Type: Observational
• Enrollment (Actual): 96

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 13 years to 18 years (Child, Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Retrospective review of all patients with Adolescent Idiopathic Scoliosis patients operated at our hospital during study period

Description

Inclusion Criteria:

• Patients with adolescent idiopathic scoliosis
• Age more than 10 years at time of surgery
• Posterior instrumentation consisting of all pedicle screw construct except for bilateral hooks at the uppermost instrumented vertebra
• A major curve magnitude between 45 and 80 degrees.

Exclusion Criteria:

• Scoliosis patients with a diagnosis other than adolescent idiopathic scoliosis
• Previous spine surgery
• Use of spinal osteotomies in addition to posterior spinal fusion with pedicle screws
• ALenke 5 curve
• Patients with less than 2 years' follow-up
• Use of hooks or wires below the uppermost instrumented level

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Degree of correction achieved	(Preop Cobb angle - Postop Cobb angle/ Preop Cobb angle * 100)	2 years
Cobb angle	Cobb angle is measured as angle sub-tented between the upper and lower end vertebrae (end vertebrae is defined as the vertebra that is most tilted from the horizontal apical vertebra)	2 years

Collaborators and Investigators

• Sponsor: Ghurki Trust and Teaching Hospital
• Investigators: Principal Investigator: Dr Irfan Qadir, Department of Orthopaedics and Spine Surgery, Ghurki Trust Teaching Hospital; Study Director: Prof.Amer Aziz, Professor and Chief, Department of Orthopaedics and Spine Surgery, Ghurki Trust Teaching Hospital; Study Chair: Abdullah Shah, Assistant Professor, Department of Orthopaedics and Spine Surgery, Ghurki Trust Teaching Hospital; Study Chair: Syed Roman Alam, Resident, Department of Orthopaedics and Spine Surgery, Ghurki Trust Teaching Hospital; Study Chair: Haseeb Hussain, Senior Registrar, Department of Orthopaedics and Spine Surgery, Ghurki Trust Teaching Hospital; Study Chair: Prof.Rizwan Akram, Professor, Department of Orthopaedics and Spine Surgery, Ghurki Trust Teaching Hospital

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2014
• Primary Completion (Actual): December 1, 2016
• Study Completion (Actual): December 1, 2016

Study Registration Dates

• First Submitted: November 11, 2019
• First Submitted That Met QC Criteria: November 21, 2019
• First Posted (Actual): November 22, 2019

Study Record Updates

• Last Update Posted (Actual): November 22, 2019
• Last Update Submitted That Met QC Criteria: November 21, 2019
• Last Verified: November 1, 2019

More Information

Terms related to this study

• Keywords: Pakistan; Adolescent idiopathic scoliosis; posterior instrumentation; metal density; correction
• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Spinal Diseases; Bone Diseases; Spinal Curvatures; Scoliosis
• Other Study ID Numbers: 19

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No