Condylar Offset and Outcomes in Primary Total Knee Arthroplasty (OFFSET-TKA)

April 3, 2026 updated by: Baris Acar, SB Istanbul Education and Research Hospital

Prospective Evaluation of Posterior and Anterior Condylar Offset and Their Impact on Functional Outcomes in Primary Total Knee Arthroplasty

This prospective cohort study aims to evaluate the effect of posterior condylar offset (PCO) and anterior condylar offset (ACO) changes on functional outcomes after primary total knee arthroplasty (TKA). Standardized imaging and clinical assessment protocols will be used to determine optimal PCO and ACO ranges associated with improved postoperative range of motion, patient-reported outcomes, and reduced anterior knee symptoms.

Study Overview

Status

Not yet recruiting

Conditions

Knee Arthritis Osteoarthritis

Study Type

Observational

Enrollment (Estimated)

100

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

Adult
Older Adult

Accepts Healthy Volunteers

Sampling Method

Non-Probability Sample

Study Population

patients undergoing primary total knee arthroplasty for osteoarthiritis

Description

Inclusion Criteria:

diagnosis of primary knee osteoarthiritis
indication of knee arthroplasty
50-85 years
ability t oprovide informed consent and comply with follow up

Exclusion Criteria:

revision knee arthroplasty
inflammatory arthritis
severe corona deformity (>20 varus/valgus)
previous knee surgery or fracture

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Number of groups / cohorts

Cohorts and Interventions

Group / Cohort
Primary TKA Cohort Participants undergoing primary total knee arthtoplasty for knee osteoarthiritis will be prospectively followed. Patients will be evaluated based on postoperative changes in posterior condylar offset and anterior condylar offset.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Maximum Knee Flexion Time Frame: 12 months postoperatively	maximum active knee flexion measured in degrees using a goniometer during clinical examination	12 months postoperatively

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Knee Society Score Time Frame: 3,6,12 months postoperatively	The Knee Society Score (KSS) is a clinician-reported outcome measure consisting of two components: the Knee Score (pain, stability, and range of motion) and the Function Score (walking distance and stair climbing). Each component ranges from 0 to 100, with a total possible score of 200. Higher scores indicate better knee function and clinical outcomes.	3,6,12 months postoperatively
WOMAC score Time Frame: 3,6,12 months postoperatively	The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) is a patient-reported outcome measure assessing pain, stiffness, and physical function. The total score ranges from 0 to 96, with higher scores indicating worse pain, stiffness, and functional limitation.	3,6,12 months postoperatively
Change in Anterior and Posterior Condylar Offset Time Frame: preoperative graphy and postoperative 1st day graphy	difference between preoperative and postoperative 1st day anterior condylar offset mesaured on lateral knee radiographs	preoperative graphy and postoperative 1st day graphy

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

SB Istanbul Education and Research Hospital

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

May 1, 2026

Primary Completion (Estimated)

December 1, 2026

Study Completion (Estimated)

July 1, 2027

Study Registration Dates

First Submitted

March 28, 2026

First Submitted That Met QC Criteria

April 3, 2026

First Posted (Actual)

April 8, 2026

Study Record Updates

Last Update Posted (Actual)