A Modified Placement of Two Additional Pedicle Screws at the Fracture Level for the Treatment of Thoracolumbar Burst Fractures--a Study Protocol of a Randomised Controlled Trial

Controversies exist about the best treatment of burst fractures of the thoracolumbar spine. Adding screws in fractured segment has been proved in many literatures that can improve construct stiffness but sometimes aggravate the trauma of fractured vertebra. Therefore, we are eager to find an optimized placement of two additional pedicle screws at the fracture level for the treatment of thoracolumbar burst fractures. This is the first randomised controlled study investigating efficacy of diverse orders of pedicle screws placement and will provide recommendations for treating patients with thoracolumbar burst fractures.

Study Overview

• Status: Unknown
• Conditions: Posterior Short-segment Pedicle Instrumentation
• Intervention / Treatment: Device: fractured level screws-distraction

Detailed Description

A blinded randomised controlled trial (blinding for the patient and statistician, rather than for the clinician and researcher) will be conducted. A total of seventy patients with single thoracolumbar AO type A3 or A4 fractures who are candidates for application of short-segment pedicle screws of fractured vertebrae will be randomly allocated to either the DS group (distraction-screws ) or the SD group (screws-distraction) at a ratio of 1: 1. The primary clinical outcome measures are compression ratio of anterior border of vertebral body height, depth of nail into injured vertebrae and kyphosis (Cobb) angle. Secondary clinical outcome measures are complications, Visual Analogue Scale (VAS) of back and leg pain, neurological function, operating time, intraoperative blood loss, Japanese Orthopaedic Association (JOA) scores and Oswestry Disability Index. These parameters will be evaluated preoperatively, intraoperatively, on day 3 postoperatively and then at 1, 3, 6, 12 and 24 months postoperatively.

• Study Type: Interventional
• Enrollment (Anticipated): 70
• Phase: Not Applicable

Contacts and Locations

Study Locations

• China
  • Zhejiang
    • Wenzhou, Zhejiang, China, 325000
      • Recruiting
      • The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University
      • Contact: WENFEI NI

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion criteria

1. 18 years of age or above.
2. single thoracolumbar burst fractures
3. AO type A3 or A4 fractures
4. Thoracolumbar Injury Classification and Severity Score (TLICS) of more than 4 and duration of < 2 weeks
5. application of posterior short-segment pedicle screws instrumentation at the fracture level Exclusion criteria

1. previous pedicle instrumentation at the same level 2. multi-segmental thoracolumbar fractures or not AO type A3 or A4 are found 3. pregnancy 4. active infection or surgical site of the previous infection 5. planned emigration abroad within 2 years after inclusion 6. suffering from illness or long-term use of certain drugs affecting the stability of the spinal environment, such as metabolic bone disease, spinal tuberculosis and so on 7. the current use of anticoagulant (such as warfarin) or postoperative heparin for more than 6 months

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Screw-Distraction (SD) group; six pedicle screws were implanted firstly, then distraction was achieved.	Device: fractured level screws-distraction; four pedicle screws were implanted into the upper vertebra and the lower vertebral body of the fractured vertebra. Then, immediate reduction and decompression were achieved by applying distraction of rod. Finally, two additional screws were introduced at fracture level
Experimental: Distraction-Screw (DS) group; four pedicle screws were implanted firstly, then distraction was achieved, two additional screws were introduced at the fracture level at last.	Device: fractured level screws-distraction; four pedicle screws were implanted into the upper vertebra and the lower vertebral body of the fractured vertebra. Then, immediate reduction and decompression were achieved by applying distraction of rod. Finally, two additional screws were introduced at fracture level

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
compression ratio change of anterior border of vertebral body height	using X-ray fluorescence	preoperatively, intraoperatively, on day 3 postoperatively and then at 1, 3, 6, 12 and 24 months postoperatively
Depth of nail into injured vertebrae	using X-ray fluorescence	at postoperation immediately
Kyphosis (Cobb) angle change	using X-ray fluorescence	preoperatively, intraoperatively, on day 3 postoperatively and then at 1, 3, 6, 12 and 24 months postoperatively

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Operative time	Unit of Measure is hour	right after surgery
intraoperative blood loss	Unit of Measure is ml	right after surgery
Complications	Pedicle fractures, intraoperative pars fractures, postoperative infection, deep venous thrombosis, nerve injury, and any other direct or indirect surgical complications will be recorded.	at postoperation immediately, 1, 3 and 6 months, and at 1 and 2 years postoperatively.
pain degree of back and lower limb	The pain degree of back and lower limb during follow-up will be assessed by the VAS of back pain and VAS of leg pain	preoperatively, on day 3 postoperatively and then at 1, 3, 6, 12 and 24 months postoperatively.
Oswestry Disability Index (ODI) change	The Oswestry Disability Index (ODI) will be asssessed by questionnaire	preoperatively, on day 3 postoperatively and then at 1, 3, 6, 12 and 24 months postoperatively
The Japanese Orthopaedic Association (JOA) scores	Functional improvement is expressed by the rate of recovery of the JOA scores	preoperatively and postoperatively including day 3 and then 1, 3, 6, 12 and 24 months
The American Spinal Injury Association (ASIA) impairment scale	Spinal Injury was assessed using ASIA	preoperatively, on day 3 postoperatively and then at 1, 3, 6, 12 and 24 months postoperatively

Collaborators and Investigators

• Sponsor: Second Affiliated Hospital of Wenzhou Medical University

Publications and helpful links

General Publications

• Hu ZC, Li XB, Feng ZH, Wang JQ, Gong LF, Xuan JW, Fu X, Jiang BJ, Wu L, Ni WF. Modified pedicle screw placement at the fracture level for treatment of thoracolumbar burst fractures: a study protocol of a randomised controlled trial. BMJ Open. 2019 Jan 28;9(1):e024110. doi: 10.1136/bmjopen-2018-024110.

Study record dates

Study Major Dates

• Study Start (Anticipated): December 1, 2018
• Primary Completion (Anticipated): December 30, 2019
• Study Completion (Anticipated): December 30, 2019

Study Registration Dates

• First Submitted: December 5, 2017
• First Submitted That Met QC Criteria: December 19, 2017
• First Posted (Actual): December 27, 2017

Study Record Updates

• Last Update Posted (Actual): August 28, 2018
• Last Update Submitted That Met QC Criteria: August 26, 2018
• Last Verified: August 1, 2018

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Wounds and Injuries; Fractures, Bone
• Other Study ID Numbers: SAHoWMU-CR2017-08-115

Drug and device information, study documents

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