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

This study has been completed.
University Hospital Inselspital, Berne
Information provided by (Responsible Party):
AO Clinical Investigation and Documentation Identifier:
First received: May 18, 2010
Last updated: January 24, 2013
Last verified: January 2013
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.

Condition Intervention
Spinal Diseases
Device: DensiProbe Spine

Study Type: Observational
Study Design: Observational Model: Case-Only
Time Perspective: Prospective
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

Resource links provided by NLM:

Further study details as provided by AO Clinical Investigation and Documentation:

Primary Outcome Measures:
  • Surgeon's compliance- and handling-oriented questionnaire [ Time Frame: Baseline ]
    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

  • Intra- and post-operative adverse events [ Time Frame: Up to 2 months postsurgery ]
    All intra- and postoperative adverse events will be assessed and analyzed regarding their relationship to the study device

Secondary Outcome Measures:
  • Bone mineral density [ Time Frame: Baseline ]
    The bone mineral density will be measured preoperatively in the lumbar spine (L1-L4) using DXA in order to assess local bone status.

  • Pedicle screw migration [ Time Frame: 2 months postsurgery ]
    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

  • QCT analysis of bone biopsies [ Time Frame: Baseline ]
    For each vertebral body under investigation a probe of trabecular bone is obtained to determine bone quality using quantitative micro-CT analysis

  • Application of bone cement [ Time Frame: Baseline ]
    For each patient the surgeon decides whether or not augmentation with bone cement is necessary

Enrollment: 30
Study Start Date: August 2010
Study Completion Date: August 2012
Primary Completion Date: March 2012 (Final data collection date for primary outcome measure)
Groups/Cohorts Assigned Interventions
Transpedicular stabilization
Patients undergoing transpedicular stabilization of the spine
Device: DensiProbe Spine
Intraoperative DensiProbe Spine measurements

Detailed 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.


Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
Patients undergoing transpedicular stabilization of the spine

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
  Contacts and Locations
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Please refer to this study by its identifier: NCT01126385

Klinik Sonnenhof
Bern, BE, Switzerland, 3006
Bern, BE, Switzerland, 3010
Sponsors and Collaborators
AO Clinical Investigation and Documentation
University Hospital Inselspital, Berne
Principal Investigator: Lorin M Benneker, MD University Hospital Inselspital, Berne
  More Information

Responsible Party: AO Clinical Investigation and Documentation Identifier: NCT01126385     History of Changes
Other Study ID Numbers: DensiProbe Spine 2010
Study First Received: May 18, 2010
Last Updated: January 24, 2013

Keywords provided by AO Clinical Investigation and Documentation:
Spinal Diseases
Bone strength
Transpedicular fixation
Dorsal instrumentation

Additional relevant MeSH terms:
Spinal Diseases
Bone Diseases
Musculoskeletal Diseases processed this record on May 25, 2017