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Bespoke vs Standard Instrumentation in TKR

Randomised Control Trial of Patient Specific Instrumentation vs Standard Instrumentation of the GMK-Sphere (Global Medacta Knee) Total Knee Arthroplasty

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT05579951
Acronym
SPHERE
Enrollment
172
Registered
2022-10-14
Start date
2021-09-21
Completion date
2024-12-31
Last updated
2025-01-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Knee Osteoarthritis

Keywords

Total knee arthroplasty, Stability, Osteoarthritis, Knee, Functional Outcome, Gait, Patient Specific Instrumentation

Brief summary

Total knee replacements are operations that are offered to patients who have severe arthritis pain that is affecting daily activities that is no longer controlled with painkillers. The operation will replace the worn joints with metal implants and a plastic spacer. Total knee replacements are successful operations in the vast majority of patients. However, a small minority of patients are not entirely satisfied with the outcome of their knee replacement. Researchers are studying whether the precise positioning of the implant has an effect on the outcome. This study will look at whether patient-specific instrumentation improves implant position and if it leads to improved patient function so that we know what to recommend in the future.

Interventions

Total knee replacement with patient specific instrumentation

PROCEDUREConventional

Total knee replacement with conventional instrumentation

Sponsors

University of Manchester
CollaboratorOTHER
Manchester University NHS Foundation Trust
Lead SponsorOTHER_GOV

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
SINGLE (Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* Patients with osteoarthritis of the knee which is sufficiently symptomatic to require knee arthroplasty as assessed by their consultant orthopaedic surgeon

Exclusion criteria

* Patients with inflammatory arthropathy, patients requiring bone augmentation, patients with ligament incompetence or valgus deformity \>5 degrees.

Design outcomes

Primary

MeasureTime frameDescription
Change from Baseline Gait Kinematics at 1-Year1 year post-operativelyGait of patients will be analysed pre-operatively, six-weeks post-operatively, and 1-year post-operatively by 3D motion capture technology. The change measured over time at 1-year will be the primary outcome.

Secondary

MeasureTime frameDescription
Oxford Knee Score (Patient reported outcome measure of pain and function)6 weeks post-operativelyA joint specific questionnaire which asks patients on the level of pain and function they believe to have in their affected knee (taking into consideration the past 4 weeks only). The questionnaire consists of 12 questions. Five of the questions are pain related, and seven are aimed at function. Each question has 5 options and is scored from 0-4, with 4 being the best and 0 being the worst pain/function. The best score is therefore 48 (no pain/good function), and the worst score is 0 (pain and poor function).
EuroQol-5 Dimensions (EQ-5D) (Patient reported outcome measure of patients' perception of their overall health)6 weeks post-operativelyA questionnaire on patients' perception of their overall health. The questionnaire focuses on generic health in 5 dimensions: Mobility, self-care, pain or discomfort, anxiety or depression and usual activities (including work, housework, leisure, family, and study). The questions are scored using an algorithm; the result of which relates to the health status of the patient. This score ranges between 0 (equivalent to death) to 1 (equivalent to full health). It also contains a visual analogue scale where patients have to choose on a scale of 0-100 how well they believe their general health to be on that particular day, where 0 is the worst health imaginable and 100 is the best health imaginable.
Patient Satisfaction (Pain/Hospital experience/functional ability/Surgery expectations)1 year post-operativelyPatient satisfaction will be reported using a scale on a questionnaire which asks six questions on how happy patients were with their hospital experience/level of pain/functional ability post-operatively. The questionnaire also asks whether their expectations were met. The two satisfaction questions are answered on a scale of 'Very Satisfied/Satisfied/Unsure/Dissatisfied' by ticking the appropriate box. The four questions based on patient expectation are scored on a scale of 'Excellent/Good/Unsure/Poor' by ticking the appropriate box.
Short Form-12 (SF-12) (Patient reported outcome measure of general quality of life)6 weeks post-operativelyA general Quality of Life score with 12 questions. It has mental and physical components which are scored from the same questions, using different algorithms. Each question is multiple choice, and the patient must tick one answer. Each answer corresponds to a standardised value, which is used in two algorithms to generate an overall score. One score is for the mental component and one is for the physical component. The physical standardized values are summed across all 12 items. 56.57706 is added to the sum to create the SF-12 physical score. 60.75781 is added to sum create the SF-12 mental score. Higher overall scores are better than lower scores.
Knee range of motion6 weeks post-operativelyKnee range of motion in degrees will be assessed using a goniometer
EuroQol-5 Dimensions (EQ-5D) (Patient reported outcome measure of patients'1 year post-operativelyA questionnaire on patients' perception of their overall health. The questionnaire focuses on generic health in 5 dimensions: Mobility, self-care, pain or discomfort, anxiety or depression and usual activities (including work, housework, leisure, family, and study). The questions are scored using an algorithm; the result of which relates to the health status of the patient. This score ranges between 0 (equivalent to death) to 1 (equivalent to full health). It also contains a visual analogue scale where patients have to choose on a scale of 0-100 how well they believe their general health to be on that particular day, where 0 is the worst health imaginable and 100 is the best health imaginable.

Countries

United Kingdom

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026