Pilot Study to Evaluate Feasibility of DensiProbe Spine Assessing Bone Strength in Spinal Surgery

Spinal Diseases Clinical Trial

— DensiProbe  

Official title:

A Prospective Case Series to Evaluate Handling and Feasibility of DensiProbe Spine Assessing Vertebral Bone Strength in Patients Undergoing Transpedicular Fixation of the Spine - a Pilot Study

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01126385
• Other study ID #: DensiProbe Spine 2010
• Status: Completed
• Phase: N/A
• First received: May 18, 2010
• Last updated: January 24, 2013
• Start date: August 2010
• Est. completion date: August 2012

Study information

• Verified date: January 2013
• Source: AO Clinical Investigation and Documentation
• Contact: n/a
• Is FDA regulated: No
• Health authority: Switzerland: Swissmedic
• Study type: Observational

Clinical Trial Summary

A new mechanical device was developed in order to provide the surgeon with intraoperative information about the mechanical strength of the cancellous bone within the vertebral body. DensiProbe Spine is intended to be used in patients undergoing transpedicular stabilization of the thoracolumbar spine. The objective of the DensiProbe Spine pilot study is to investigate the handling and feasibility of the DensiProbe Spine measurement device.

Description:

Osteoporotic fragility fractures often occur in the spine. A common surgical technique is the transpedicular fixation using pedicle screws. A major complication of this treatment is a cut-out or back-out of the screw due to insufficient anchorage of the implant in the vertebral body.

A new mechanical device was developed in order to provide the surgeon with intraoperative information about the mechanical strength of the cancellous bone. In cases of low bone quality, the treatment can be adapted to the patient's condition, for example by augmentation of the screw anchorage using bone cement. However, this treatment involves a risk of cement leakage and subsequent pulmonary embolism or nerve damage. Furthermore, cement augmentation is time-consuming. Therefore, there is a need for a diagnostic device that can intraoperatively support the surgeon's decision on the appropriate treatment.

DensiProbe Spine was developed accordingly to the clinically approved DensiProbe Hip, which was designed for the same diagnostic reasons in patients with hip fractures undergoing fracture fixation with the dynamic hip screw (DHS). However, the application of bone strength measurements in the spine is in so far different to the hip as the anatomical dimensions in the spine are much smaller and lower values of bone mineral density (BMD) and bone strength are expected.

The objective of this pilot study is to investigate the handling and feasibility of the newly developed DensiProbe Spine measurement device. In case of a positive result of the pilot study, a multicenter cohort study will be performed in order to clinically validate the DensiProbe Spine device by assessing the correlation between DensiProbe Spine measurements and the amounts of pedicle screw migration in patients undergoing transpedicular fixation.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 30
• Est. completion date: August 2012
• Est. primary completion date: March 2012
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• Age 18 or older

• Indication for transpedicular fixation of the thoracolumbar spine

• Ability to understand and read local language at an elementary level

• Signed informed consent by patient or legal guardian to participate in the study according to the protocol

Exclusion Criteria:

• Patients who are legally incompetent

• Scoliosis (Cobb angle on AP radiograph > 10°)

• Benign or malign vertebral bone tumour

• Active malignancy

• Infection diseases, eg. hepatitis, human immunodeficiency virus (HIV)

• Pre-drilling with power-drill

• Life-threatening condition

• Drug or alcohol abuse

• Participation in any other medical device or drug study that could influence the results of the present study

Study Design

Observational Model: Case-Only, Time Perspective: Prospective

Related Conditions & MeSH terms

• Spinal Diseases

Intervention

Device:
• DensiProbe Spine
Intraoperative DensiProbe Spine measurements

Locations

Country	Name	City	State
Switzerland	Inselspital	Bern	BE
Switzerland	Klinik Sonnenhof	Bern	BE

Sponsors (2)

Lead Sponsor	Collaborator
AO Clinical Investigation and Documentation	University Hospital Inselspital, Berne

Country where clinical trial is conducted

Switzerland, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Surgeon's compliance- and handling-oriented questionnaire	The general satisfaction of the surgeon with DensiProbe Spine as well as specific problems that are likely to occur during the measurement with DensiProbe Spine will be assessed	Baseline	No
Primary	Intra- and post-operative adverse events	All intra- and postoperative adverse events will be assessed and analyzed regarding their relationship to the study device	Up to 2 months postsurgery	Yes
Secondary	Bone mineral density	The bone mineral density will be measured preoperatively in the lumbar spine (L1-L4) using DXA in order to assess local bone status.	Baseline	No
Secondary	Pedicle screw migration	The migration of the pedicle screw will be performed by measuring the angle between the pedicle screw axis and the caudal endplate. The amount of screw migration is defined as the difference in that angle between the baseline (postoperative) and the two month lateral x-rays	2 months postsurgery	No
Secondary	QCT analysis of bone biopsies	For each vertebral body under investigation a probe of trabecular bone is obtained to determine bone quality using quantitative micro-CT analysis	Baseline	No
Secondary	Application of bone cement	For each patient the surgeon decides whether or not augmentation with bone cement is necessary	Baseline	No