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Undisplaced Femoral Neck Fractures 2 Hansson Pins or 3 Pins Interlocked in Plate (Pinloc) Using RSA

Not Applicable
Completed
Conditions
Femoral Neck Fractures
Hip Fractures
Interventions
Device: 2 Hansson pins
Device: Pinloc
Registration Number
NCT02699619
Lead Sponsor
Oslo University Hospital
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.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
26
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)

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
2 Hansson pins without plate2 Hansson pinsPatients with undisplaced femoral neck fractures operated with 2 isolated Hansson pins.
3 Hansson pins interlocked in a platePinlocPatients with undisplaced femoral neck fractures operated with 3 Hansson pins interlocked in plate (Pinloc).
Primary Outcome Measures
NameTimeMethod
Change in fracture displacement during healing measured with radiostereometryUp to 52 weeks

Will be measured by RSA postoperatively, before discharge and after 4, 8, 12, 24 and 52 weeks. Total displacement from first reading to the reading showing maximum displacement is the main outcome.

Secondary Outcome Measures
NameTimeMethod
Reoperation for healing problems52 weeks

Any additional surgery addressing healing problems or hardware failure

Eq5d4 weeks

Hrqol.

Change in time to union as measured by RSA (cessation of motion) and radiographsWill be examined at 4, 12, 26 and 52 weeks

When RSA shows that no motion has happened between two time points the fracture will be regarded as healed at the former time point.

Timed Up and Go test52 weeks

Tug

Motion during healing as measured by plain radiographs.Up to 52 weeks

Will be measured by RSA postoperatively, before discharge and after 4,12, 24 and 52 weeks.

Time of surgery1 week
Satisfaction with operated hip (NRS)52 weeks

NRS

Motion during healing as measured by radiostereometry.Up to 52 weeks

Will be measured by RSA postoperatively, before discharge and after 4, 12, 24 and 52 weeks.

Mortality52 weeks

Any reason

Perioperative blood loss1 week
Change in time to union as measured by plain radiographs and clinical findingsWill be examined at 4,12, 26 and 52 weeks

Composite endpoint: Healing defined by obliteration of fracture line radiographically and pain free weight bearing (except lateral pain from hardware), when this occurs the fracture will be considered healed.

Postoperative pain (NRS) while in hospital1 week

Pain at mobilization (NRS) at discharge

Harris Hip ScoreUp to 52 weeks

Will be examined at 4,12, 26 and 52 weeks

Pain (NRS)52 weeks

Maximum hip pain during the last week

Trial Locations

Locations (1)

Orthopedic Center, Ulleval University Hospital

đŸ‡³đŸ‡´

Oslo, Norway

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