Clinical trial NCT02699619: Undisplaced Femoral Neck Fractures 2 Hansson Pins or 3 Pins Interlocked in Plate (Pinloc) Using RSA
Official title: Undisplaced Femoral Neck Fractures Treated With 2 Hansson Pins Without Plate or 3 Hansson Pins Interlocked in a Plate (Pinloc) - A Randomized Controlled Trial Using Radiostereometry
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Hip Fractures
Femoral Neck Fractures
Keywords: Undisplaced
Lead sponsor: Oslo University Hospital
Sponsor class: OTHER
Collaborators: name: Diakonhjemmet Hospital
First posted: 2016-03-04
Enrollment: 26
Sex: ALL
Minimum age (years): 60
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: Femoral neck fractures represent about half of the hip fractures and are further divided into displaced and undisplaced fractures. Displaced femoral neck fractures are almost always treated surgically with arthroplasty. However there is an ongoing debate on which implant is superior for undisplaced fractures.

A novel implant design (Pinloc) has been developed by Swemac Innovation AB. While the original implant consisted of 2 isolated hook pins, the modified design consists of 3 titanium hook pins interlocked in an aluminum plate. Interlocking is a new principle of implant design and improves fixation and load transfer amongst the pins. The superiority of the modified design is so far only proven preclinically.

The role of the Pinloc in clinical use remains unclear. Investigators are planning a randomized controlled trial on undisplaced femoral neck fractures to establish a method for implanting the tantalum markers, to observe the fracture healing process and to further investigate the role of the Pinloc.

Detailed description: Femoral neck fractures represent about half of the hip fractures and are further divided into displaced and undisplaced fractures. Displaced femoral neck fractures are almost always treated surgically with arthroplasty. However there is an ongoing debate on which implant is superior for undisplaced fractures.

A novel implant design (Pinloc) has been developed by Swemac Innovation AB. While the original implant consisted of 2 isolated hook pins, the modified design consists of 3 titanium hook pins interlocked in an aluminum plate. Interlocking is a new principle of implant design and improves fixation and load transfer amongst the pins. The superiority of the modified design is so far only proven preclinically. The role of the Pinloc in clinical use remains unclear.

A series of studies is now planned at Oslo University Hospital in collaboration with Diakonhjemmet Hospital in hope to further clarify this debate. The use of the Pinloc has been introduced in some regions (e.g. Norway, Sweden and Japan). The role of the Pinloc remains unclear and very little has been published on it's use, even though it is believed to be an important contributor of stability to the fixation.

Femoral neck fractures are mainly caused by a fall from own height in the elderly. The fractures are most often classified as displaced or not, using the simplified Garden classification. Several other classification systems also exist, but these have not been shown to be of reliable clinical usefulness. The ideal classification system should be easily applicable, reliable, and aid in treatment decision making and prognosis.

The treatment of femoral neck fractures comprise perioperative and operative modalities. The perioperative modalities consist among others of medical optimalization preoperatively, early rehabilitation and prevention of new fractures by treating osteoporosis and preventing new falls. The main scope of the current study will, however, be the operative modalities.

Surgery for undsiplaced femoral neck fractures is performed mainly with internal fixation on a traction table, using either screws, pins or a sliding hip screw (SHS), available in various designs from different manufacturers. The latest Cochrane review did not conclude on which implant is the superior.

Radiostereometry (RSA) is the most precise and accurate method to measure motion in vivo between different segments in orthopaedic research. To do so, radioopaque tantalum markers are implanted into the bone defining different segments. Stereoradiographs are performed over time to detect movement and monitor the healing (or non healing) process. This movement can be calculated both as translations and rotations. They are ideal to describe and compare the stability of fracture systems. RSA has been used successfully in earlier studies on fracture healing. Due to the high accuracy and precision, RSA yield reliable results with relatively small study-groups. Investigators plan to use RSA to measure fracture dislocation and time to healing in our studies. The study will be on the function of the Pinloc and it´s ability to prevent secondary dislocation in undisplaced femoral neck fractures. Investigators will utilize RSA for measurements during follow-up.

Eligibility criteria: Inclusion Criteria:

* undisplaced femoral neck fractures
* able to walk independently, aids such as crutches or walker allowed
* able to consent
* fit for surgery with pins with or without plate

Exclusion Criteria:

* not willing or able to attain follow up
* previous fracture or surgery with retained metal work in the same hip
* concomitant disease that will shorten life expectancy (i.e. cancer, COPD)

Primary outcomes:
measure: Change in fracture displacement during healing measured with radiostereometry
timeFrame: Up to 52 weeks
Secondary outcomes:
measure: Perioperative blood loss
timeFrame: 1 week
measure: Time of surgery
timeFrame: 1 week
measure: Eq5d
timeFrame: 52 weeks
measure: Eq5d
timeFrame: 26 weeks
measure: Eq5d
timeFrame: 12 weeks
measure: Eq5d
timeFrame: 4 weeks
measure: Change in time to union as measured by RSA (cessation of motion) and radiographs
timeFrame: Will be examined at 4, 12, 26 and 52 weeks
measure: Change in time to union as measured by plain radiographs and clinical findings
timeFrame: Will be examined at 4,12, 26 and 52 weeks
measure: Harris Hip Score
timeFrame: Up to 52 weeks
measure: Postoperative pain (NRS) while in hospital
timeFrame: 1 week
measure: Timed Up and Go test
timeFrame: 4 weeks
measure: Timed Up and Go test
timeFrame: 12 weeks
measure: Timed Up and Go test
timeFrame: 26 weeks
measure: Timed Up and Go test
timeFrame: 52 weeks
measure: Pain (NRS)
timeFrame: 4 weeks
measure: Pain (NRS)
timeFrame: 12 weeks
measure: Pain (NRS)
timeFrame: 26 weeks
measure: Pain (NRS)
timeFrame: 52 weeks
measure: Satisfaction with operated hip (NRS)
timeFrame: 4 weeks
measure: Satisfaction with operated hip (NRS)
timeFrame: 12 weeks
measure: Satisfaction with operated hip (NRS)
timeFrame: 26 weeks
measure: Satisfaction with operated hip (NRS)
timeFrame: 52 weeks
measure: Motion during healing as measured by radiostereometry.
timeFrame: Up to 52 weeks
measure: Motion during healing as measured by plain radiographs.
timeFrame: Up to 52 weeks
measure: Reoperation for healing problems
timeFrame: 52 weeks
measure: Mortality
timeFrame: 52 weeks
Other outcomes:
Locations:
city: Oslo
country: Norway
facility: Orthopedic Center, Ulleval University Hospital
Study officials:
affiliation: Oslo UH
name: Frede Frihagen, PhD
role: PRINCIPAL_INVESTIGATOR
References: