Unicompartmental Knee Arthroplasty Preferred Over Total Knee Replacement for Function
Overview
This study compared gait loading patterns in patients with both unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) on contralateral limbs. Results demonstrated that UKA limbs showed more normal loading patterns during walking and incline gait, suggesting better functional restoration compared to TKA. These findings support UKA as the preferred option for patients with single compartment knee osteoarthritis.
Background
Up to 47% of patients with symptomatic knee osteoarthritis in the UK have single compartment disease, yet most receive total knee arthroplasty (TKA), which removes the anterior cruciate ligament and affects otherwise healthy compartments. Unicompartmental knee arthroplasty (UKA) preserves more native knee anatomy and is medically safer but has a higher revision rate long term. Previous studies have shown small functional advantages of UKA, but selection bias and clinical relevance remain concerns. This study uniquely compares gait loading in patients with both UKA and TKA to assess which procedure better restores normal function.
Data Highlights
Group
Number of Patients
Implants Used
Walking Speed (km/h)
Incline (%)
UKA and TKA Patients
16
4 TKA types, 2 UKA types
4.5
5
Healthy Controls
Demographically similar
N/A
4.5
5
Unilateral Medial OA Patients
Demographically similar
N/A
4.5
5
Key Findings
Patients with both UKA and TKA on contralateral knees showed different limb loading patterns during gait.
UKA limbs demonstrated loading patterns closer to healthy controls compared to TKA limbs.
Incline walking at 5% further highlighted functional advantages of UKA over TKA.
UKA preserves the anterior cruciate ligament and healthy compartments, contributing to better gait mechanics.
Despite higher revision rates, UKA offers superior restoration of normal knee function in daily activities.
Selection bias was minimized by studying patients with both procedures, controlling for patient factors.
Clinical Implications
Clinicians should consider unicompartmental knee arthroplasty as the preferred surgical option for patients with isolated medial compartment osteoarthritis to better restore natural knee function and gait. While TKA remains common, UKA offers improved patient-reported outcomes and more physiological limb loading, which may enhance activities of daily living. Careful patient selection and surgical expertise remain important given the higher revision rates associated with UKA.
Conclusion
This study provides evidence that unicompartmental knee arthroplasty better restores normal gait loading compared to total knee arthroplasty in patients with single compartment disease. UKA should be considered the preferred treatment option to optimize functional outcomes.
References
TOPKAT Trial -- Partial vs Total Knee Arthroplasty
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