Total knee arthroplasty with the Medial-Pivot knee system: Clinical and radiological outcomes at 9.5 years' mean follow-up.
Orthop Traumatol Surg Res
; 104(2): 185-191, 2018 04.
Article
in En
| MEDLINE
| ID: mdl-29274863
ABSTRACT
INTRODUCTION:
The "ball-in-socket" design of the Medial-Pivot knee system (MicroPort Orthopedics, Arlington, Tennessee, USA) aims to reproduce normal knee kinematics by medializing its rotational axis. The goal of this study was to measure knee range of motion (ROM) with this implant after a mean follow-up of 10 years and to report the survivorship and long-term clinical and radiological outcomes. We hypothesized the prosthetic knee would have at least 120° flexion at 10 years. MATERIAL ANDMETHODS:
This was retrospective, single-centre study of 74 Medial-Pivot knees implanted in 71 patients (average age of 69 years) between May 2005 and November 2007. All patients who received a Medial-Pivot knee were included consecutively. The mean follow-up was 10 years. Clinical and radiological assessments were performed using the Knee Society Score (KSS) and Ewald's score. Kaplan-Meir survival analysis was used to calculate survivorship.RESULTS:
Seven percent of cases were lost to follow-up. The knee ROM was 110° at 10 years. The survivorship was 93% for all revision causes and 95.9% when revisions due to trauma or infection were excluded. The mean KSS score was 195. Stable radiolucent lines were found in 14% of cases. No aseptic loosening was observed.CONCLUSION:
Our hypothesis was not confirmed. Knee flexion at the final follow-up was comparable to other semi-constrained implant designs but was not as large as expected. The survival of the Medial-Pivot knee at 10 years is good. Its radiological and clinical outcomes are satisfactory. LEVEL OF EVIDENCE IV (retrospective cohort study).Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Arthroplasty, Replacement, Knee
/
Knee Joint
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Knee Prosthesis
Type of study:
Diagnostic_studies
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Observational_studies
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Prognostic_studies
Limits:
Adult
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Aged
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Aged80
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Female
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Humans
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Male
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Middle aged
Language:
En
Journal:
Orthop Traumatol Surg Res
Year:
2018
Document type:
Article