Influence of Bone Strength Measured by DensiProbe on Bone Related Fixation Failure

Osteoporosis Clinical Trial

— Densiprobe  

Official title:

Prospective Multicenter Cohort Study to Evaluate the Influence of Bone Strength Measured by DensiProbe Hip on Bone Related Fixation Failure in Patients With Hip Fractures Undergoing DHS Surgical Treatment.

Clinical Trial Details — Status: Terminated

Administrative data

• NCT number: NCT00822159
• Other study ID #: Densiprobe-08
• Status: Terminated
• Phase: N/A
• First received: January 13, 2009
• Last updated: October 7, 2011
• Start date: November 2008
• Est. completion date: September 2011

Study information

• Verified date: October 2011
• Source: AO Clinical Investigation and Documentation
• Contact: n/a
• Is FDA regulated: No
• Health authority: Switzerland: Ethikkommission
• Study type: Interventional

Clinical Trial Summary

Hip fractures mostly occur in elderly people with low bone strength. Bone strength is determined by bone mineral density (BMD), bone turnover, microarchitectural and geometrical properties of the bone. Dual energy x-ray absorptiometry (DXA) is the standard technique to measure BMD. However, BMD just provides information regarding the quantity of mineral in bone, which is only one component of bone strength. To date there is no reliable method to assess bone strength in vivo. Therefore, a method to assess bone strength beyond BMD would provide additional information regarding the patients' risk of bone related fixation failure after fracture fixation.

DensiProbe is a new diagnostic device that was developed for intra-operative assessment of mechanical stability of the bone in the proximal femur. It consists of a drill bit like tool and an electronic system to measure the peak torque to break-away of trabecular bone in the femoral head of patients undergoing DHS surgical treatment. In a cadaver study comparing bone mineral density measured by quantitative computed tomography with bone strength measured by DensiProbe a high correlation between these two parameters could be shown. In a clinical pilot study a significant correlation between DensiProbe measurements and BMD measured by DXA at the femoral neck in patients with hip fractures could be shown. However, no perfect correlation was expected because DensiProbe measures bone strength, which is only partly caused by BMD.

Bone related fixation failure, such as secondary loss of reduction, is influenced by bone strength, bone mineral density, fracture type, fracture reduction and primary positioning of the implant. The predictive value of DensiProbe measurements for secondary loss of reduction needs to be investigated. If DensiProbe turned out to be an effective screening tool for patients with low bone strength that are on higher risk of the aforementioned complications these patients may in future benefit from alternative treatment methods (e.g. augmentation techniques) in order to reduce bone related fixation failure.

The primary aim of the present study is to investigate if bone strength measured by DensiProbeTM Hip (DensiProbe) is an independent factor to predict secondary loss of reduction (screw migration of 5 mm or more and / or telescoping of 10 mm or more) in patients with hip fractures after fracture fixation with DHS.

Recruitment information / eligibility

• Status: Terminated
• Enrollment: 198
• Est. completion date: September 2011
• Est. primary completion date: September 2011
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 50 Years and older

Eligibility

Inclusion Criteria:

• Patients 50 years or older

• Patients with trochanteric or femoral neck fractures, classified as: AO 31-A1, AO 31-A2, AO 31-A3, AO 31-B1, AO 31-B2, AO 31-B3

• Patients undergoing fixation with DHS (135° aiming device, anti-rotational K-wire)

• Patients willing to participate in the study according to the clinical investigation plan

• Patients able to understand and read country national language at an elementary level

• Signed written informed consent by the patient or legal guardian

Exclusion Criteria:

• Bilateral hip fractures (at present or in the past)

• Open hip fracture

• Any previous surgical procedures of the hip (ipsilateral / contralateral)

• More than 7 days between injury and surgery

• Polytrauma (multiple injuries, whereof one or the combination of several injuries is life-threatening)

• Patients being pregnant or breast-feeding

• Pathologic fractures

• Active malignancy

• Psychiatric disorders that would preclude reliable assessment (e.g. severe depression)

• Drug or alcohol abuse

• Patients having participated in any other device or drug related clinical trial within the previous month

Study Design

Allocation: Non-Randomized, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Diagnostic

Related Conditions & MeSH terms

• Bone Density
• Femoral Fractures
• Fractures, Bone
• Hip Fractures
• Osteoporosis

Intervention

Device:
• DensiProbe Hip
DensiProbe (CE marked) is a mechanical probe, which is used intra-operatively to assess mechanical stability of the trabecular bone in the proximal femur. It consists of a drill bit like tool and an electronic system for measuring the peak torque to break-away of trabecular bone in the femoral head. DensiProbe measurements are designed to be integrated in the DHS surgical procedure.

Locations

Country	Name	City	State
Austria	Medizinische Universität	Innsbruck
Austria	Wilhelminenspital	Wien
Germany	Medizinische Hochschule Hannover	Hannover
Germany	Friedrich-Schiller Universität	Jena
Germany	Universitätsklinikum Münster	Münster
Netherlands	Twenteborg Ziekenhuis Almelo	Almelo
Switzerland	Universitätsspital	Basel	BS
Switzerland	Stadtspital Triemli	Zürich

Sponsors (1)

Lead Sponsor	Collaborator
AO Clinical Investigation and Documentation

Countries where clinical trial is conducted

Austria,  Germany,  Netherlands,  Switzerland, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Migration of the screw in relation to the femoral head of 5 mm or more and/or Telescoping (shortening of the femoral neck) of 10 mm or more		3 months	No
Secondary	Rate of complications		3 months	No
Secondary	BMD values measured by DXA (contralateral hip)		Post OP	No
Secondary	Parker mobility score		3 months	No

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