Preoperative Multimorbidity and Functional Recovery After Total Knee Arthroplasty

October 31, 2026 updated by: güneş sarıkaya, Balikesir Ataturk City Hospital

Effect of Preoperative Multimorbidity Burden on the Trajectory of Functional Recovery After Primary Total Knee Arthroplasty: A Single-Center Prospective Observational Cohort Study

This prospective observational cohort study aims to investigate the association between preoperative multimorbidity burden and functional recovery after primary total knee arthroplasty (TKA) in patients with knee osteoarthritis.

Approximately 230 adult patients undergoing elective unilateral primary TKA will be enrolled at a single hospital in Türkiye. Preoperative multimorbidity burden will be assessed using the Functional Comorbidity Index (FCI), which measures the presence of medical conditions that may affect physical function.

Patients will be evaluated before surgery and at 6 and 12 months after surgery. Functional outcomes and pain will be assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Oxford Knee Score (OKS). Anxiety and depressive symptoms will be evaluated using the Hospital Anxiety and Depression Scale (HADS).

The primary objective is to determine whether higher preoperative multimorbidity burden is associated with poorer physical function at 12 months after TKA. The study will also examine changes in functional recovery over time and other clinical outcomes.

All surgical procedures, postoperative care, and rehabilitation will follow routine clinical practice. No additional treatment or experimental intervention will be assigned as part of this study.

Study Overview

Status

Recruiting

Conditions

Detailed Description

Total knee arthroplasty (TKA) is an effective surgical treatment for advanced knee osteoarthritis, providing substantial improvements in pain and physical function. However, the extent and trajectory of postoperative recovery vary considerably among patients. Preoperative multimorbidity may influence recovery, although previous studies have reported inconsistent findings regarding its association with postoperative functional improvement.

This single-center, prospective observational cohort study will evaluate the relationship between preoperative multimorbidity burden and functional recovery after elective unilateral primary TKA.

A target sample of 230 adult patients undergoing primary TKA for knee osteoarthritis will be consecutively enrolled. The sample size accounts for potential loss to follow-up, with a target of at least 166 patients completing the 12-month assessment.

Preoperative multimorbidity burden will be evaluated using the Functional Comorbidity Index (FCI), an 18-item index developed to assess comorbidity burden in relation to physical function. Comorbid conditions will be identified through patient interviews and verified using medical records and medication histories.

Patient-reported outcomes will be collected preoperatively and at 6 and 12 months postoperatively. The WOMAC will assess pain, stiffness, and physical function, while the Oxford Knee Score (OKS) will provide an additional assessment of knee-related pain and function. The Hospital Anxiety and Depression Scale (HADS) will assess psychological symptom burden.

The primary outcome will be the WOMAC physical function subscale score at 12 months after surgery. Secondary assessments will examine longitudinal changes in WOMAC scores, OKS, HADS, knee range of motion, patient satisfaction, postoperative complications, hospital readmissions, manipulation under anesthesia, and revision surgery.

All patients will receive posterior-stabilized primary knee prostheses and follow the institution's standard postoperative rehabilitation protocol. Surgical procedures will be performed by orthopedic surgeons according to routine clinical practice. No additional treatment or alteration to standard care will be introduced for research purposes.

The primary analysis will assess the association between baseline FCI score and 12-month WOMAC physical function score using multivariable linear regression, adjusting for prespecified clinical

Study Type

Observational

Enrollment (Estimated)

230

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

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

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

N/A

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

The study population will consist of adult patients aged 18 years or older with primary knee osteoarthritis who are scheduled to undergo elective unilateral primary total knee arthroplasty at the Department of Orthopedics and Traumatology, Balikesir Ataturk City Hospital, Türkiye.

Eligible patients will be consecutively recruited during the study enrollment period. All participants will receive standard surgical treatment and postoperative rehabilitation according to routine institutional practice. Participants will be followed prospectively, with clinical and patient-reported outcome assessments performed preoperatively and at 6 and 12 months after surgery.

Description

Inclusion Criteria:

  • Adults aged 18 years or older.
  • Scheduled for elective unilateral primary total knee arthroplasty due to primary knee osteoarthritis.
  • Sufficient cognitive and communication abilities to understand and complete the study questionnaires.
  • Provision of written informed consent for study participation.

Exclusion Criteria:

  • Patients scheduled for revision total knee arthroplasty.
  • Patients scheduled for simultaneous bilateral total knee arthroplasty.
  • Arthroplasty indicated for inflammatory arthritis, tumor, infection, or post-traumatic conditions.
  • Severe cognitive impairment, advanced dementia, or communication difficulties preventing valid completion of the study questionnaires.
  • Significant logistical or legal circumstances preventing completion of the planned follow-up assessments.

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

  • Observational Models: COHORT
  • Time Perspectives: PROSPECTIVE

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
WOMAC Physical Function Subscale Score at 12 Months
Time Frame: 12 months after surgery

Physical function will be assessed using the 17-item physical function subscale of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), using the validated Turkish Likert version. Each item is scored from 0 to 4, yielding a total subscale score ranging from 0 to 68. Higher scores indicate greater functional limitations.
12 months after surgery

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in WOMAC Physical Function Score From Baseline
Time Frame: Baseline (preoperative), 6 months and 12 months after surgery

Change in the WOMAC physical function subscale score from baseline to 6 and 12 months after surgery. The subscale contains 17 items scored from 0 to 4, with a total score ranging from 0 to 68. Higher scores indicate greater functional limitations. Change will be calculated as the follow-up score minus the baseline score; negative values indicate improvement.
Baseline (preoperative), 6 months and 12 months after surgery

Collaborators and Investigators

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

Sponsor

Balikesir Ataturk City Hospital

Investigators

  • Principal Investigator: Güneş SARIKAYA, Balikesir Ataturk City Hospital

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 (Actual)

June 26, 2026

Primary Completion (Estimated)

August 1, 2028

Study Completion (Estimated)

August 1, 2028

Study Registration Dates

First Submitted

October 13, 2026

First Submitted That Met QC Criteria

October 13, 2026

First Posted (Actual)

October 20, 2026

Study Record Updates

Last Update Posted (Actual)

November 4, 2026

Last Update Submitted That Met QC Criteria

October 31, 2026

Last Verified

October 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • TKA-FCI-2026-01

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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