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

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

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.

Study Overview

• Status: Completed
• Conditions: Hip Fractures; Femoral Neck Fractures
• Intervention / Treatment: Device: 2 Hansson pins; Device: 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.

• Study Type: Interventional
• Enrollment (Actual): 26
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Norway
  • Oslo, Norway, 0408
    • Orthopedic Center, Ulleval University Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 60 years and older (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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 Plan

How is the study designed?

Design Details

• Primary Purpose: TREATMENT
• Allocation: RANDOMIZED
• Interventional Model: PARALLEL
• Masking: NONE

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: 2 Hansson pins without plate; Patients with undisplaced femoral neck fractures operated with 2 isolated Hansson pins.	Device: 2 Hansson pins; 2 isolated hook pins.(Without plate); Other Names: 2 isolated hook pins.
Active Comparator: 3 Hansson pins interlocked in a plate; Patients with undisplaced femoral neck fractures operated with 3 Hansson pins interlocked in plate (Pinloc).	Device: Pinloc; 3 hook pins interlocked in plate.; Other Names: 3 hook pins interlocked in plate.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in fracture displacement during healing measured with radiostereometry	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.	Up to 52 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Perioperative blood loss		1 week
Time of surgery		1 week
Eq5d	Health Related Quality of Life (Hrqol).	52 weeks
Eq5d	Hrqol.	26 weeks
Eq5d	Hrqol.	12 weeks
Eq5d	Hrqol.	4 weeks
Postoperative pain (NRS) while in hospital	Pain at mobilization (NRS) at discharge	1 week
Pain (NRS)	Maximum hip pain during the last week	4 weeks
Pain (NRS)	Maximum hip pain during the last week	12 weeks
Pain (NRS)	Maximum hip pain during the last week	26 weeks
Pain (NRS)	Maximum hip pain during the last week	52 weeks
Reoperation for healing problems	Any additional surgery addressing healing problems or hardware failure	52 weeks
Mortality	Any reason	52 weeks
Change in time to union as measured by RSA (cessation of motion) and radiographs	When RSA shows that no motion has happened between two time points the fracture will be regarded as healed at the former time point.	Will be examined at 4, 12, 26 and 52 weeks
Change in time to union as measured by plain radiographs and clinical findings	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.	Will be examined at 4,12, 26 and 52 weeks
Harris Hip Score	Will be examined at 4,12, 26 and 52 weeks	Up to 52 weeks
Timed Up and Go test	Tug	4 weeks
Timed Up and Go test	Tug	12 weeks
Timed Up and Go test	Tug	26 weeks
Timed Up and Go test	Tug	52 weeks
Satisfaction with operated hip (NRS)	NRS	4 weeks
Satisfaction with operated hip (NRS)	NRS	12 weeks
Satisfaction with operated hip (NRS)	NRS	26 weeks
Satisfaction with operated hip (NRS)	NRS	52 weeks
Motion during healing as measured by radiostereometry.	Will be measured by RSA postoperatively, before discharge and after 4, 12, 24 and 52 weeks.	Up to 52 weeks
Motion during healing as measured by plain radiographs.	Will be measured by RSA postoperatively, before discharge and after 4,12, 24 and 52 weeks.	Up to 52 weeks

Collaborators and Investigators

• Sponsor: Oslo University Hospital
• Collaborators: Diakonhjemmet Hospital
• Investigators: Principal Investigator: Frede Frihagen, PhD, Oslo UH

Study record dates

Study Major Dates

• Study Start (Actual): March 1, 2016
• Primary Completion (Actual): April 1, 2021
• Study Completion (Actual): May 1, 2021

Study Registration Dates

• First Submitted: January 20, 2016
• First Submitted That Met QC Criteria: March 3, 2016
• First Posted (Estimate): March 4, 2016

Study Record Updates

• Last Update Posted (Actual): May 11, 2021
• Last Update Submitted That Met QC Criteria: May 10, 2021
• Last Verified: May 1, 2021

More Information

Terms related to this study

• Keywords: Undisplaced
• Additional Relevant MeSH Terms: Wounds and Injuries; Leg Injuries; Femoral Fractures; Hip Injuries; Fractures, Bone; Hip Fractures; Femoral Neck Fractures
• Other Study ID Numbers: 2015/191/REK SO B

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: International peer review journal