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

Sponsor

AO Clinical Investigation and Publishing Documentation (Other)

Overall Status

Terminated

CT.gov ID

NCT00822159

Collaborator

(none)

198

Enrollment

Locations

Duration (Months)

24.8

Patients Per Site

0.7

Patients Per Site Per Month

Study Details

Study Description

Brief 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.

Condition or Disease	Intervention/Treatment	Phase
Femoral Fractures Hip Fractures Osteoporosis Bone Density	Device: DensiProbe Hip	N/A

Study Design

Study Type:

Interventional

Anticipated Enrollment :

198 participants

Allocation:

Non-Randomized

Intervention Model:

Single Group Assignment

Masking:

None (Open Label)

Primary Purpose:

Diagnostic

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.

Study Start Date :

Nov 1, 2008

Actual Primary Completion Date :

Sep 1, 2011

Actual Study Completion Date :

Sep 1, 2011

Outcome Measures

Primary Outcome Measures

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]

Secondary Outcome Measures

Rate of complications [3 months]
BMD values measured by DXA (contralateral hip) [Post OP]
Parker mobility score [3 months]

Eligibility Criteria

Criteria

Ages Eligible for Study:

50 Years and Older

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

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

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	Medizinische Universität	Innsbruck		Austria
2	Wilhelminenspital	Wien		Austria
3	Medizinische Hochschule Hannover	Hannover		Germany
4	Friedrich-Schiller Universität	Jena		Germany
5	Universitätsklinikum Münster	Münster		Germany
6	Twenteborg Ziekenhuis Almelo	Almelo		Netherlands
7	Universitätsspital	Basel	BS	Switzerland	4031
8	Stadtspital Triemli	Zürich		Switzerland