SHould You transFer the Tubercle? (SHYFT)

A Randomized Clinical Pilot Trial Comparing Isolated Medial Patellofemoral Ligament Reconstruction to Medial Patellofemoral Ligament Reconstruction Combined With Tibial Tubercle Osteotomy: SHould You transFer the Tubercle (SHYFT)?

The aim of this study is to investigate the role of tibial tubercle osteotomy (TTO) on the subjective and objective outcomes following medial patellofemoral ligament reconstruction (MPFL-R) in patients with an increased tibial tubercle-trochlear groove (TT-TG) distance with or without patella alta.

This Pilot RCT will assess the feasibility of conducting this study for:

1. The ability to recruit study patients
2. Adherence to the study protocol
3. Completion rates of patient follow-up at a minimum of 12 months post-operative

Study Overview

• Status: Recruiting
• Conditions: Tibial Tubercle Osteotomy; Patellofemoral Dislocation; Medial Patellofemoral Ligament Reconstruction
• Intervention / Treatment: Procedure: Medial patellofemoral ligament reconstruction

Detailed Description

For patients with recurrent lateral patellofemoral instability, a medial patellofemoral ligament reconstruction (MPFL-R) consistently provides significant improvements in symptoms, quality of life, and return to sport. During an MPFL-R the surgeon will place a soft tissue graft from the medial patella to the femur. The graft used to create the new MPFL can be autograft (usually hamstring tendon) or allograft.

The tibial tubercle osteotomy (TTO) is a procedure designed to change the vector of the pull of the quadricep muscles by moving the insertion point of the patellar tendon. This is achieved by transferring the tendon with a block of bone to allow for consistent and reliable healing. The TTO is a versatile procedure that can move the patellar tendon insertion medially, anteriorly, or distally, or a combination of these directions. It can be used to correct a lateralized tibial tubercle or patella alta.

Despite the association of an increased TT-TG distance with patellofemoral instability, it has been difficult to demonstrate a correlation with patient outcomes after patellar stabilisation surgery. In addition, studies have been unable to correlate the pre-operative presence of patella alta with clinical outcomes after MPFL-R.

This randomized clinical pilot trial will randomly allocate patients with lateral patellofemoral instability and an elevated TT-TG distance with or without patella alta ato receive either an isolated MPFL-R or an MPFL-R in combination with a correcting TTO (medializing, distalizing, or a combination of both).

Patients will be followed for two years post-operative with subjective outcome measures and objective clinical and functional testing.

The study groups will be:

1. Isolated MPFL-R
2. MPFL-R with a TTO

The primary outcome measures will be:

1. Number of study patients recruited
2. Adherence to the study protocol (number of protocol deviations)
3. Follow-up completion rates of study patients at a minimum of 12 months post-operative

Secondary outcome measures include the Banff Patellar Instability Instrument 2.0 (BPII 2.0), functional testing, clinical assessment, complications, re-dislocation rate, post-operative pain scores, patient satisfaction, and patient-reported outcome scores.

If feasibility is demonstrated via this Pilot RCT, a larger RCT will be designed to answer important questions on how to optimize outcomes and limit morbidity after MPFL-R.

• Study Type: Interventional
• Enrollment (Estimated): 30
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Laurie A Hiemstra, MD, PhD; Phone Number: 6 403 760 2897; Email: hiemstra@banffsportmed.ca
• Study Contact Backup: Name: Sarah Kerslake, BPhty; Phone Number: 6 403 760 2897; Email: sarah@banffsportmed.ca

Study Locations

• Canada
  • Alberta
    • Canmore, Alberta, Canada, T1W 0L5
      • Recruiting
      • Banff Sport Medicine
      • Contact: Laurie Hiemstra, MD PhD FRCSC; Phone Number: 4037602897

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age 13-30 years
• Symptomatic recurrent lateral patellofemoral instability
• TT-TG ≥15mm measured on MRI or ≥18mm on CT scan
• Closed physes (confirmed on knee x-rays)

Exclusion Criteria:

• Caton-Deschamps ratio ≥ 1.4 on lateral radiographs
• Femoral anteversion ≥ 25 degrees on diagnostic imaging rotational profile
• Tibial external rotation ≥ 45 degrees on diagnostic imaging rotational profile
• High-grade trochlear dysplasia requiring trochleoplasty
• Significant osteoarthritis on skyline plain imaging (Kellgren Lawrence grade ≥ 2)
• A chondral lesion of the patellofemoral joint that is undergoing a cartilage restoration procedure.
• Unable to complete computer-based outcome questionnaires
• Pregnant (at time of surgery)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: MPFL-R; Medial patellofemoral ligament reconstruction	Procedure: Medial patellofemoral ligament reconstruction; Medial patellofemoral ligament reconstruction
Active Comparator: MPFL-R + TTO; Medial patellofemoral ligament reconstruction with concomitant tibial tubercle osteotomy	Procedure: Medial patellofemoral ligament reconstruction; Medial patellofemoral ligament reconstruction

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Study Feasibility - patient recruitment	Number of study patients recruited	12-months post-operative
Study Feasibility - protocol adherence	Adherence to the study protocol (total number of protocol deviations)	12-months post-operative
Study Feasibility - follow-up completion	Number of patients completing follow-up a minimum of 12 months post-operative	12-months post-operative

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Banff Patellofemoral Instability Instrument (BPII 2.0)	Disease-specific patient-reported outcome measure that assesses quality of life across 5 domains. Scored out of 100, with 100 representing the maximum score for disease-specific quality of life.	Baseline, and 6-,12- & 24-months post-operative
Functional Outcomes - Hop Testing	Limb Symmetry Index on 4 single-leg hop test battery (assessed as percentage score operative / non-operative limb)	6-, 12- & 24-months post-operative
Patellar Apprehension Test	Rate of positive patellar apprehension	6-, 12- & 24-months post-operative
Complications	Rate of post-operative complications including infection, blood clots, reduced range of motion, persistent pain, persistent swelling, and re-dislocations	6-, 12- & 24-months post-operative
Post-operative Knee Pain	Post-operative pain score measured on a 10-point visual analogue scale	6-, 12- & 24-months post-operative
Patient satisfaction	Measured on a 5-point Likert scale	6-, 12- & 24-months post-operative

Collaborators and Investigators

• Sponsor: Banff Sport Medicine Foundation
• Collaborators: Canadian Orthopaedic Foundation; CONMED Corporation
• Investigators: Principal Investigator: Laurie A Hiemstra, MD, PhD, University of Calgary

Study record dates

Study Major Dates

• Study Start (Actual): September 1, 2023
• Primary Completion (Estimated): December 31, 2025
• Study Completion (Estimated): September 1, 2026

Study Registration Dates

• First Submitted: February 17, 2023
• First Submitted That Met QC Criteria: February 25, 2023
• First Posted (Actual): March 8, 2023

Study Record Updates

• Last Update Posted (Estimated): December 14, 2023
• Last Update Submitted That Met QC Criteria: December 7, 2023
• Last Verified: December 1, 2023

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Wounds and Injuries; Joint Diseases; Musculoskeletal Diseases; Joint Dislocations
• Other Study ID Numbers: REB17-1256

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No