Personalised HTO Versus Generic HTO Virtual Clinical Trial

• ClinicalTrials.gov Identifier: NCT03419598
• Recruitment Status: Completed
• First Posted: February 5, 2018
• Results First Posted: December 7, 2020
• Last Update Posted: December 7, 2020
• Sponsor: University of Bath
• Collaborator: Royal Devon and Exeter NHS Foundation Trust
• Information provided by (Responsible Party): Richie Gill, University of Bath

• Study Type: Observational
• Study Design: Observational Model: Case-Control; Time Perspective: Prospective
• Condition: Osteoarthritis, Knee
• Interventions: Procedure: Opening wedge high tibial osteotomy; Device: Personalised subject specific custom HTO plate; Device: Generic HTO plate
• Enrollment: 30

Participant Flow

Recruitment Details	The virtual patients were created based on CT data sets obtained for 30 patients with knee osteoarthritis. The virtual patients were duplicated, and then enrolled into both arms.
Pre-assignment Details

Arm/Group Title	All Study Participants
Arm/Group Description	Opening wedge high tibial osteotomy (HTO). Realignment of knee by creating an opening wedge osteotomy in the upper part of the tibia. Since this is a virtual trial, the virtual patients were duplicated and had the osteotomy stabilised by a generic HTO plate in one copy of the cohort and by a personalised HTO plate in the other copy.
Period Title: Overall Study
Started [1]	30
Subject Specific Tibia Models Created and Virtual Osteotomy Performed	28
Virtual Cohort Duplicated Into A. Personalised and B. Generic Copies	28
Finite Element (FE) Model Created for Cohort Copy Stabilised by Personalised HTO Plate	28
FE Models Created for Cohort Copy Stabilised by Generic HTO Plate	28
FE Models Solved for Personalised HTO Plate Stabilised Cohort Copy	28
FE Models Solved for Generic HTO Plate Stabilised Cohort Copy	28
Completed	28
Not Completed	2
Reason Not Completed
Poor quality CT scans could not be adequately segmented to create virtual patient tibial geometry	2
[1] Since this is a virtual trial, the virtual patients were duplicated and enrolled into both arms

Baseline Characteristics

Arm/Group Title		All Study Participants
Arm/Group Description		Opening wedge high tibial osteotomy (HTO): Realignment of knee by creating an opening wedge osteotomy in the upper part of the tibia Cohort duplicated into 2 copies. Copy A. Stabilised by Personalised HTO plate. Copy B. Stabilised by Generic HTO plate.
Overall Number of Baseline Participants		28
Baseline Analysis Population Description		[Not Specified]
Age, Categorical; Measure Type: Count of Participants; Unit of measure: Participants
	Number Analyzed	28 participants
	<=18 years	0 0.0%
	Between 18 and 65 years	10 35.7%
	>=65 years	18 64.3%
Age, Continuous; Mean (Standard Deviation); Unit of measure: Years
	Number Analyzed	28 participants
		67.7 (9.0)
Sex: Female, Male; Measure Type: Count of Participants; Unit of measure: Participants
	Number Analyzed	28 participants
	Female	15 53.6%
	Male	13 46.4%
Race and Ethnicity Not Collected [1]; Measure Type: Count of Participants; Unit of measure: Participants
	Number Analyzed	0 participants
		[1] Measure Analysis Population Description: Race and Ethnicity were not collected from any participant.
Region of Enrollment; Measure Type: Number; Unit of measure: Participants
United Kingdom	Number Analyzed	28 participants
		28
Height (m); Mean (Standard Deviation); Unit of measure: Metres
	Number Analyzed	28 participants
		1.686 (0.124)
Weight (kg); Mean (Standard Deviation); Unit of measure: Kg
	Number Analyzed	28 participants
		90.1 (16.4)
Kellgren & Lawrence OA Grade [1]; Mean (Standard Deviation); Unit of measure: Units on a scale
	Number Analyzed	28 participants
		2.6 (0.9)
		[1] Measure Description: Radiographic grading scale for osteoarthritis (OA) of a joint. Grade 0 (none): definite absence of x-ray changes of osteoarthritis. Grade 1 (doubtful): doubtful joint space narrowing and possible osteophytic lipping. Grade 2 (minimal): definite osteophytes and possible joint space narrowing. Grade 3 (moderate): moderate multiple osteophytes, definite narrowing of joint space and some sclerosis and possible deformity of bone ends. Grade 4 (severe): large osteophytes, marked narrowing of joint space, severe sclerosis and definite deformity of bone ends.

Outcome Measures

1. Primary Outcome

Title	Mechanical Stress in Plate During Gait
Description	Mechanical stress (Von Mises) calculated for functional loading using finite element analysis
Time Frame	6 weeks simulated post-operation

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Personalised HTO	Generic HTO
Arm/Group Description:	Opening wedge high tibial osteotomy Personalised subject specific custom HTO plate Opening wedge high tibial osteotomy: Realignment of knee by creating an opening wedge osteotomy in the upper part of the tibia Stabilised by personalised HTO plate, contoured to subject's tibial geometry	Opening wedge high tibial osteotomy Generic HTO plate Opening wedge high tibial osteotomy: Realignment of knee by creating an opening wedge osteotomy in the upper part of the tibia Generic HTO plate: Generic plate for stabilizing an open wedge HTO
Overall Number of Participants Analyzed	28	28
Mean (Standard Error); Unit of Measure: MPa
	108.3 (3.81)	90.6 (3.56)

2. Secondary Outcome

Title	Mechanical Strain in Bone Around Screws During Gait
Description	Mechanical strain calculated for functional loading using finite element analysis, note strain is dimensionless and hence has no units
Time Frame	6 weeks simulated post-operation

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Personalised HTO	Generic HTO
Arm/Group Description:	Opening wedge high tibial osteotomy Personalised subject specific custom HTO plate Opening wedge high tibial osteotomy: Realignment of knee by creating an opening wedge osteotomy in the upper part of the tibia Stabilising by personalised HTO contoured to subject's tibial geometry	Opening wedge high tibial osteotomy Generic HTO plate Opening wedge high tibial osteotomy: Realignment of knee by creating an opening wedge osteotomy in the upper part of the tibia Generic HTO plate: Generic plate for stabilizing an open wedge HTO
Overall Number of Participants Analyzed	28	28
Mean (Standard Error); Unit of Measure: unitless
	0.011 (0.00056)	0.011 (0.00065)

Adverse Events

Time Frame	Adverse Events were not monitored/assessed
Adverse Event Reporting Description	Adverse Events were not monitored/assessed
Arm/Group Title	All Study Participants
Arm/Group Description	Opening wedge high tibial osteotomy (HTO): Realignment of knee by creating an opening wedge osteotomy in the upper part of the tibia. Virtual cohort duplicated into A. stabilised by Personalised HTO plate and B. stabilised by Generic HTO plate.
All-Cause Mortality
	All Study Participants
	Affected / at Risk (%)
Total	0/0
Serious Adverse Events
	All Study Participants
	Affected / at Risk (%)
Total	0/0
Other (Not Including Serious) Adverse Events
Frequency Threshold for Reporting Other Adverse Events	0%
	All Study Participants
	Affected / at Risk (%)
Total	0/0

Limitations and Caveats

The main failure mode of HTO plates is fatigue failure, if the peak stress is below the fatigue limit the risk of fatigue failure is low.

More Information

Certain Agreements

Principal Investigators are NOT employed by the organization sponsoring the study.

There is NOT an agreement between Principal Investigators and the Sponsor (or its agents) that restricts the PI's rights to discuss or publish trial results after the trial is completed.

Results Point of Contact

• Name/Title: Professor Richie Gill
• Organization: University of Bath
• Phone: 01225 383627
• EMail: r.gill@bath.ac.uk

• Responsible Party: Richie Gill, University of Bath
• ClinicalTrials.gov Identifier: NCT03419598
• Other Study ID Numbers: RG433_TVT003
• First Submitted: January 26, 2018
• First Posted: February 5, 2018
• Results First Submitted: October 5, 2019
• Results First Posted: December 7, 2020
• Last Update Posted: December 7, 2020