Patient Specific Instrumentation (PSI) Referencing Osteotomy Technological Transfer - a Randomized Control Trial (RCT)

Study Overview
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Brief Summary
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Medial open wedge high tibial osteotomy is a surgery performed to treat knee osteoarthritis in young patients.Recently with our department advance of technology, the investigators performed computed tomography for the patient's lower limb and 3D reconstruct the image. Based on the 3D image, the investigators planned our planned osteotomy cut on computer software Materialize 3 and the investigators then 3D printed a metal jig that has a slot to produce the osteotomy and also protected the neurovascular bundles. Therefore these metal jigs are specific to each patients. The investigators have performed a few cases of HTO under this extra metal jig protection and guidance and noted it has improved accuracy and safety clinically. However, whether it has scientific significance difference in accuracy is not known.

Detailed Description
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Medial open wedge high tibial osteotomy is a surgery performed to treat knee osteoarthritis in young patients. Currently the investigators perform high tibial osteotomy under the guidance of computer navigation to achieve the required alignment. During conventional high tibial osteotomy the bone cut is done by free hand cutting, there are risks of cutting into the posterior proximal tibia compartment and transect the neurovascular bundles which is a surgical disaster and may then lead to loss of limb. And the accuracy of free hand cutting is limited by experience of surgeons. In our conventional high tibial osteotomy transection of neurovascular bundles has never happened given our meticulous surgical technique but the investigators believe an extra protection is always beneficial to our patients. Recently with our department advance of technology, the investigators performed computed tomography for the patient's lower limb and 3D reconstruct the image. Based on the 3D image, the investigators planned our planned osteotomy cut on computer software Materialize 3 and the investigators then 3D printed a metal jig that has a slot to produce the osteotomy and also protected the neurovascular bundles. Therefore these metal jigs are specific to each patients. The investigators have performed a few cases of HTO under this extra metal jig protection and guidance and noted it has improved accuracy and safety clinically. However, whether it has scientific significance difference in accuracy is not known.

Official Title
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Patient Specific Instrumentation (PSI) Referencing Osteotomy Technological Transfer and Education - a PSI High Tibial Osteotomy, Double-blinded, Randomized Controlled Trial - the PROTECTED HTO (High Tibial Osteotomy) Trial

Conditions
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Osteotomy, Randomized Controlled Trial

Intervention / Treatment
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* Procedure: 3D printed patient specific metal jigs (PSI jig)
* Procedure: HTO with navigation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: symptomatic patient with medial compartment knee OA medial compartment OA was grade 3 or milder according to Kellgren-Lawrence classification Exclusion Criteria: lateral compartment OA symptomatic patellofemoral compartment OA, inflammatory arthritis, significant loss of knee joint range in flexion (less than 100°) or in extension (less than - 10°), ligamentous instability, obesity with a body mass index greater than 30, significant psychological disorder inability to communicate in Chinese or English language

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Control group: High tibial osteotomy with navigation Intervention group: High tibial osteotomy with navigation and PSI jig
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: HTO with navigation<br>High Tibial Osteotomy is offered to patients with symptomatic medial compartment knee osteoarthritis (OA) | Procedure: HTO with navigation<br>* In brief, an incision is made in the midway between posteromedial border of the tibia and medial aspect of the tibial tuberosity. Sartorius fascia is cut and retracted medially to expose the medial collateral ligament (MCL). Two to three K-wires are placed 4 cm below the medial joint line toward the safe zone (an area between the tip of the fibular head and the remnant of fibular head epiphysis line) of the lateral cortex under fluoroscopy and osteotomy is done below and parallel to the k-wires using an oscillating saw leaving the lateral 10 mm intact.<br>|
| Experimental: HTO with navigation + PSI jig<br>3D printed patient specific metal jigs (PSI jig) are created based on the pre-operative CT image. After that, calibrated osteotome is used to achieve the desired correction with the use of navigation for overall lower limb alignment, which is the same as the Active Comparator group. | Procedure: 3D printed patient specific metal jigs (PSI jig)<br>* PSI jig is created based on the pre-operative CT image. Standard medial open wedge osteotomy described previously is performed. Incision is made in the midway between posteromedial border of the tibia and medial aspect of the tibial tuberosity. Sartorius fascia is cut and retracted medially to expose the medial collateral ligament (MCL). Then the PSI jig is positioned onto the tibia. Due to the jig patient specific design (individually based on each patient's CT image), it can fit closely to the proximal tibia. The slot opening on the PSI jig corresponds to 4 cm below the medial joint line and the slot design allow the sawblade cut direction toward the safe zone of the lateral cortex under fluoroscopy. The PSI Jig is removed after the bone cut completed and would not retain in patient's body.<br>Procedure: HTO with navigation<br>* In brief, an incision is made in the midway between posteromedial border of the tibia and medial aspect of the tibial tuberosity. Sartorius fascia is cut and retracted medially to expose the medial collateral ligament (MCL). Two to three K-wires are placed 4 cm below the medial joint line toward the safe zone (an area between the tip of the fibular head and the remnant of fibular head epiphysis line) of the lateral cortex under fluoroscopy and osteotomy is done below and parallel to the k-wires using an oscillating saw leaving the lateral 10 mm intact.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Knee Society knee score | Clinical and functional scores, on a 100-point scale; Knee Society score (KSS) has a Knee Score section (7 items) and a Functional Score section (3 items). Both sections are scored from 0 to 100 with lower scores being indicative of worse knee conditions and higher scores being indicative of better knee conditions. Excellent for score 80-100, Good for score 70-79, Fair for score 60-69, Poor for score below 60. | 1 week before surgery | 
| Knee Society knee score | Clinical and functional scores, on a 100-point scale; Knee Society score (KSS) has a Knee Score section (7 items) and a Functional Score section (3 items). Both sections are scored from 0 to 100 with lower scores being indicative of worse knee conditions and higher scores being indicative of better knee conditions. Excellent for score 80-100, Good for score 70-79, Fair for score 60-69, Poor for score below 60. | 6 months post-op | 
| Knee Society knee score | Clinical and functional scores, on a 100-point scale; Knee Society score (KSS) has a Knee Score section (7 items) and a Functional Score section (3 items). Both sections are scored from 0 to 100 with lower scores being indicative of worse knee conditions and higher scores being indicative of better knee conditions. Excellent for score 80-100, Good for score 70-79, Fair for score 60-69, Poor for score below 60. | 1 year post-op | 
| Knee Society knee score | Clinical and functional scores, on a 100-point scale; Knee Society score (KSS) has a Knee Score section (7 items) and a Functional Score section (3 items). Both sections are scored from 0 to 100 with lower scores being indicative of worse knee conditions and higher scores being indicative of better knee conditions. Excellent for score 80-100, Good for score 70-79, Fair for score 60-69, Poor for score below 60. | 2 year post-op | 
| Knee Society function score | Clinical and functional scores, on a 100-point scale; Knee Society score (KSS) has a Knee Score section (7 items) and a Functional Score section (3 items). Both sections are scored from 0 to 100 with lower scores being indicative of worse knee conditions and higher scores being indicative of better knee conditions. Excellent for score 80-100, Good for score 70-79, Fair for score 60-69, Poor for score below 60. | 1 week before surgery | 
| Knee Society function score | Clinical and functional scores, on a 100-point scale; Knee Society score (KSS) has a Knee Score section (7 items) and a Functional Score section (3 items). Both sections are scored from 0 to 100 with lower scores being indicative of worse knee conditions and higher scores being indicative of better knee conditions. Excellent for score 80-100, Good for score 70-79, Fair for score 60-69, Poor for score below 60. | 6 months post-op | 
| Knee Society function score | Clinical and functional scores, on a 100-point scale; Knee Society score (KSS) has a Knee Score section (7 items) and a Functional Score section (3 items). Both sections are scored from 0 to 100 with lower scores being indicative of worse knee conditions and higher scores being indicative of better knee conditions. Excellent for score 80-100, Good for score 70-79, Fair for score 60-69, Poor for score below 60. | 1 year post-op | 
| Knee Society function score | Clinical and functional scores, on a 100-point scale; Knee Society score (KSS) has a Knee Score section (7 items) and a Functional Score section (3 items). Both sections are scored from 0 to 100 with lower scores being indicative of worse knee conditions and higher scores being indicative of better knee conditions. Excellent for score 80-100, Good for score 70-79, Fair for score 60-69, Poor for score below 60. | 2 year post-op | 
| Oxford Knee Score | Clinical and functional scores | 1 week before surgery | 
| Oxford Knee Score | Clinical and functional scores | 6 months post-op | 
| Oxford Knee Score | Clinical and functional scores | 1 year post-op | 
| Oxford Knee Score | Clinical and functional scores | 2 year post-op | 
| Range of motion | Evaluated using a manual goniometer | 1 week before surgery | 
| Range of motion | Evaluated using a manual goniometer | 1 week before discharge | 
| Range of motion | Evaluated using a manual goniometer | 3 months post-op | 
| Range of motion | Evaluated using a manual goniometer | 6 months post-op | 
| Range of motion | Evaluated using a manual goniometer | 1 year post-op | 
| Range of motion | Evaluated using a manual goniometer | 2 year post-op | 
| Pain Visual Analog Scale (VAS) score | The VAS is a psychometric response scale and a measurement instrument for subjective characteristics or attitudes that cannot be directly measured. The VAS pain ranges 0-10, with 10 representing the most pain. | 1 week before surgery | 
| Pain Visual Analog Scale (VAS) score | The VAS is a psychometric response scale and a measurement instrument for subjective characteristics or attitudes that cannot be directly measured. The VAS pain ranges 0-10, with 10 representing the most pain. | 1 week before discharge | 
| Pain Visual Analog Scale (VAS) score | The VAS is a psychometric response scale and a measurement instrument for subjective characteristics or attitudes that cannot be directly measured. The VAS pain ranges 0-10, with 10 representing the most pain. | 3 months post-op | 
| Pain Visual Analog Scale (VAS) score | The VAS is a psychometric response scale and a measurement instrument for subjective characteristics or attitudes that cannot be directly measured. The VAS pain ranges 0-10, with 10 representing the most pain. | 6 months post-op | 
| Pain Visual Analog Scale (VAS) score | The VAS is a psychometric response scale and a measurement instrument for subjective characteristics or attitudes that cannot be directly measured. The VAS pain ranges 0-10, with 10 representing the most pain. | 1 year post-op | 
| Pain Visual Analog Scale (VAS) score | The VAS is a psychometric response scale and a measurement instrument for subjective characteristics or attitudes that cannot be directly measured. The VAS pain ranges 0-10, with 10 representing the most pain. | 2 year post-op | 
| Measurement of knee displacement | Measure the displacement (in cm) between femoral head and tibial head on a secured computer using CT scan images and scanogram images | 1 week before surgery | 
| Measurement of knee displacement | Measure the displacement (in cm) between femoral head and tibial head on a secured computer using CT scan images and scanogram images | 1 year after surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Patient Specific Instrumentation, Randomized controlled trial, High Tibial Osteotomy