Matched Pair Study - Kinematic Vs Mechanical Alignment

Matched Pair Study to Assess Influence of Kinematic Versus Mechanical Alignment in Total Knee Replacement

The aim of this study is to evaluate postoperative knee function after total knee arthroplasty performed according to the anatomical alignment and compare these results to those of a matched historical cohort of patients operated with mechanical alignment.

Study Overview

• Status: Completed
• Conditions: Osteoarthritis, Knee; Joint Disease
• Intervention / Treatment: Procedure: Kinematic alignment; Device: GMK Sphere®; Procedure: Mechanical alignment

Detailed Description

The 25 patients, of the Kinematic group, are prospectively enrolled. While, the data of patients of the Mechanical group, are retrospectively collected from an historical collection.

• Study Type: Observational
• Enrollment (Actual): 50

Contacts and Locations

Study Locations

• Germany
  • North Rhine-Westphalia
    • Brakel, North Rhine-Westphalia, Germany, 33034
      • St. Vinzenz Krankenhaus Brakel

Participation Criteria

Eligibility Criteria

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

• Sampling Method: Probability Sample

Study Population

Patients will be recruited during the preoperative visit at the investigational site. All patients scheduled for a total knee replacements, meeting the inclusion criteria and none of the exclusion criteria will be invited to the study.

Description

Inclusion Criteria:

1. Patients presenting with disease that meets the indications for use for Medacta implants defined by this study (on-label use).
2. Patients necessitating primary Total Knee Replacement
3. Patients who are willing and able to provide written informed consent for participation in the study. Written informed consent must be obtained prior to the patient's surgery.

Exclusion Criteria:

1. Those with one or more medical conditions identified as a contraindication defined by the labeling on Medacta implants used in this study.
2. Previous osteotomy around the knee
3. Ligament instability likely to require higher level of constraint
4. Previous infection or inflammatory disease
5. Extraarticular deformities for which a femoral intramedullary guide rod can't be inserted into the canal and use of Computer Assisted Orthopaedic Surgery (CAOS) or Patient Specific Instrumentation (PSI) is required.

Study Plan

How is the study designed?

Design Details

• Observational Models: Case-Control
• Time Perspectives: Other

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Kinematic alignment with GMK Sphere®; Patients enrolled prospectively with surgeries planned to get kinematic alignment	Procedure: Kinematic alignment; The principle for kinematically aligning the femoral component is to remove the correct amount of bone and cartilage from the distal and posterior femur after accounting for wear and saw blade kerf, so that the total thickness of the missing and removed tissue matches the thickness of the femoral component.; Device: GMK Sphere®; The GMK Sphere® is a total knee prosthesis . The design of the GMK Sphere® is characterized by a spherical medial femoral condyle and an asymmetrical fixed tibial UHMWPE polyethylene insert with a concave spherical medial compartment.
Mechanical alignment with GMK Sphere®; Historical group who had mechanical alignment, match-paired with the prospective group	Device: GMK Sphere®; The GMK Sphere® is a total knee prosthesis . The design of the GMK Sphere® is characterized by a spherical medial femoral condyle and an asymmetrical fixed tibial UHMWPE polyethylene insert with a concave spherical medial compartment.; Procedure: Mechanical alignment; Classic mechanical alignment (MA) in total knee arthroplasty (TKA) is meant to co-align the prosthetic components to the mechanical axes of the femur and tibia and restore neutral overall limb alignment

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Compare clinical outcomes of mechanical vs kinematic with new Knee Society Score	The new KSS (from the publication of 2011, Giles R. Scuderi MD "The New Knee Society Knee Scoring System" Clin Orthop Relat Res (2012) 470:3-19) includes a part filled by the surgeon and one by the patient. The first outcome is focused on the "Functional Activities" subscore, excluding the "Discretionary knee activities". The maximum is 85 points while the minimum is -10 points. The "Functional Activities" score includes 3 subscores: WALKING AND STANDING (min -10, max 30), STANDARD ACTIVITIES (min 0, max 30) and ADVANCED ACTIVITIES (min 0, max 25)	1-year follow-up

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Patient functional improvement, satisfaction and symptoms	The functional improvement, satisfaction and symptoms is the sum of the following subscores of the new KSS: "Functional Activities", "Patient Satisfaction" and "Symptoms"	1-year follow-up
Residual deformity	The residual deformity is evaluated by long axis Xray analysis: HKA angle	1-year follow-up
Flexion-extension contracture	The flexion-extension contracture is evaluated by a subscore of the new KSS: "Joint motion"	1-year follow-up
Self-reported pain, function and stiffness	These aspects are evaluated through KOOS score	1-year follow-up
Ability to forget about artificial joint	Through the use of the Forgotten Joint Score	1-year follow-up

Collaborators and Investigators

• Sponsor: Medacta International SA

Study record dates

Study Major Dates

• Study Start (Actual): January 2, 2018
• Primary Completion (Actual): May 18, 2019
• Study Completion (Actual): May 18, 2019

Study Registration Dates

• First Submitted: February 19, 2018
• First Submitted That Met QC Criteria: February 23, 2018
• First Posted (Actual): February 26, 2018

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: December 11, 2024
• Last Verified: March 1, 2019

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Arthritis; Rheumatic Diseases; Osteoarthritis; Joint Diseases; Osteoarthritis, Knee
• Other Study ID Numbers: P02.010.18

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No