Apical Vertebral Rotation in Adolescent Idiopathic Scoliosis: Comparison of Uniplanar and Polyaxial Pedicle Screws.

09:40 EDT 29th March 2015 | BioPortfolio

Summary of "Apical Vertebral Rotation in Adolescent Idiopathic Scoliosis: Comparison of Uniplanar and Polyaxial Pedicle Screws."

Retrospective radiographic outcome analysis.
To compare residual postoperative apical vertebral rotation between uniplanar versus polyaxial bilateral pedicle screw constructs in thoracic adolescent idiopathic scoliosis (AIS). SUMMARY OF BACKGROUND
Vertebral rotation is a component of the 3-dimensional deformity of AIS. The correction of vertebral rotation is an important goal of surgery. A comparison of uniplanar versus polyaxial screws has yet to be studied.
A review of a multicenter database of Lenke type 1 to 3 AIS patients who underwent surgical correction of thoracic AIS by posterior segmental pedicle screw instrumentation and fusion with either uniplanar or polyaxial pedicle screws and 5.5-mm steel rod constructs was performed. Curves greater than 100 degrees were excluded to control for the propensity to use polyaxial screws to correct larger curves. Postoperative apical vertebral rotation of thoracic curves was graded as 0, 1, or 2 based on a computed tomography scan-validated radiographic method that uses the relative position of the screw tips to grade apical vertebral rotation at the 6-week and 1-year postoperative visits. By this grading method, higher grades correspond to greater residual apical vertebral rotation.
Two hundred and ten patients met the inclusion criteria. The uniplanar screw group included 95 patients whereas the polyaxial screw group had 115 patients. The respective mean preoperative thoracic Cobb angle of 58±12 and 60±13 degrees (P=0.1), first erect postoperative coronal correction of 72% and 74% (P=0.38), and 1-year correction of 70% and 76% (P=0.07) were not significantly different between the uniplanar and polyaxial groups. At 6 weeks postoperation, the uniplanar group had 34% of patients with grade 0 rotation, 52% with grade 1, and only 14% with grade 2 thoracic apical vertebral rotation. In the polyaxial group, only 14% of patients were grade 0, 35% were grade 1, and 51% were the most rotated grade 2. This was a significant difference in the distribution of the axial rotation grades (P<0.001), with less residual apical vertebral rotation with the use of uniplanar screws. The same pattern of results was found at 1-year postoperative evaluation (P<0.001).
There was little difference in the coronal plane correction of thoracic curves between the 2 types of screws. However, the uniplanar pedicle screw group had a larger proportion of patients with greater thoracic apical vertebral derotation (less residual apical vertebral rotation) compared with the polyaxial screw group. This can be attributed to the increase in rotational leverage afforded by uniplanar screws during intraoperative bilateral direct apical vertebral derotation maneuvers.


*Department of Orthopaedic Surgery, University of Illinois, Chicago, IL †Department of Orthopedic Surgery, University of California San Diego ‡Department of Orthopedic Surgery, Rady Children's Hospital and Health Center, San Diego, CA §Department of

Journal Details

This article was published in the following journal.

Name: Journal of spinal disorders & techniques
ISSN: 1539-2465


PubMed Articles [5492 Associated PubMed Articles listed on BioPortfolio]

Predictors of curve flexibility in adolescent idiopathic scoliosis: a retrospective study of 100 patients.

Curve flexibility in adolescent idiopathic scoliosis (AIS) was one of the major concerns of spinal surgeons since the evolution of surgical correction techniques. In this respect, many tried to identi...

Segmental torso masses in adolescent idiopathic scoliosis.

Adolescent idiopathic scoliosis is the most common type of spinal deformity whose aetiology remains unclear. Studies suggest that gravitational forces in the standing position play an important role i...

Is There a Role for the 5-Degree Rule in Adolescent Idiopathic Scoliosis?

Nonstructural curves are defined in the Lenke classification system for adolescent idiopathic scoliosis as bending out to

Investigation of the 53 markers in a DNA-based Prognostic test Revealing new Predisposition Genes for Adolescent Idiopathic Scoliosis.

A genetic association study of 53 single nucleotide polymorphisms (SNPs) with adolescent idiopathic scoliosis (AIS).

Ultrasonographic Measurements of Paraspinal Muscle Thickness in Adolescent Idiopathic Scoliosis: A Comparison and Reliability Study.

To examine paraspinal muscle asymmetries in patients with mild adolescent idiopathic scoliosis (AIS) compared with controls using ultrasound (US) imaging and to determine reliability of the US imaging...

Clinical Trials [2130 Associated Clinical Trials listed on BioPortfolio]

Scoliosis Surgery Using the PASS® LP System

The purpose of this study is to find out the outcomes of using the PASS LP System to correct adolescent idiopathic scoliosis. This system is a unique set of spinal instrumentation used to ...

An Aerobic Exercising Program on Respiratory Muscle Strength in Patients With Adolescent Idiopathic Scoliosis

Adolescent Idiopathic Scoliosis (AIS) can change the respiratory dynamics and performance of the inspiratory and expiratory muscles, affecting ventilatory capacity. This was a randomized, ...

Bracing in Adolescent Idiopathic Scoliosis Trial (BrAIST)

Adolescent idiopathic scoliosis (AIS) is a structural curve of the spine with no clear underlying cause. Bracing is currently the standard of care for preventing curve progression and trea...

Calcium + Vitamin D Supplementation for Low Bone Mass in Adolescent Idiopathic Scoliosis (AIS)

The purpose of this study is to determine whether Calcium and Vit D supplementation is effective for improving low bone mass in Girls with Adolescent Idiopathic Scoliosis (AIS).

Validation of a New Generation of Optimized Orthoses for Personalized Treatment of Adolescent Idiopathic Scoliosis

Adolescent Idiopathic scoliosis affects 3-4% of the Canadian population, of which about 10% will need a brace treatment during pubertal growth spurt. The design is made relatively corsets ...

Medical and Biotech [MESH] Definitions

Deformities of the SPINE characterized by abnormal bending or flexure in the vertebral column. They may be bending forward (KYPHOSIS), backward (LORDOSIS), or sideway (SCOLIOSIS).

Comparison of various psychological, sociological, or cultural factors in order to assess the similarities or diversities occurring in two or more different cultures or societies.

The rotation of linearly polarized light as it passes through various media.

Any observable response or action of an adolescent.

An adolescent who is receiving long-term in-patient services or who resides in an institutional setting.

Search BioPortfolio:

Relevant Topics

Latest News Clinical Trials Research Drugs Reports Corporate
Rheumatology is the medical specialty concerned with the diagnosis and management of disease involving joints, tendons, muscles, ligaments and associated structures (Oxford Medical Dictionary). It is an active area of medical research, because of the d...

Latest News Clinical Trials Research Drugs Reports Corporate
Orthopedics is the science or practice of correcting deformities caused by disease or damage to the bones and joints of the skeleton. This specialized branch of surgery may involve operation, manipulation, traction or prostheses. (Oxford Medical Dictiona...