An observational study in Knee Osteoarthritis and Multimorbidity, sponsored by Balikesir Ataturk City Hospital. Recruiting at 1 site in Turkey (Türkiye). Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-20.
Sponsored by Balikesir Ataturk City Hospital · Observational
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.
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
3,391 studies on the registry are indexed under Osteoarthritis, Knee; 628 are open to participants now.
This study's planned enrollment of 230 is above the median of 100 across 484 observational studies indexed under Osteoarthritis, Knee.
Browse Osteoarthritis, Knee studies →Balikesir Ataturk City Hospital is the lead sponsor of 3 studies on the registry; 3 are open to participants now.
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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.
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Exclusion Criteria:
WOMAC Physical Function Subscale Score at 12 Months
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.
Time frame: 12 months after surgery
Change in WOMAC Physical Function Score From Baseline
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.
Time frame: Baseline (preoperative), 6 months and 12 months after surgery
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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Balikesir Ataturk City Hospital