ARTHROPLASTY
Monoblock versus modular polyethylene insert in uncemented total knee arthroplasty
OrthoEvidence Journal (OE Journal) - ACE Report
OE Journal. 2017;5(15):5 Acta Orthop. 2016 Dec;87(6):607-61467 patients scheduled for total knee arthroplasty were randomized to receive either a monoblock or modular tibial component. Patients were assessed for component migration over the first 24 months postoperatively, as well as clinical scores in the same time frame. Results demonstrated significantly lower maximum total point motion in the monoblock group compared to the modular group after 24 months. As well, single dimension migration demonstrated significantly lower subsidence in the monoblock group compared to the modular group. Clinical scores did not significantly differ between groups.
Was the allocation sequence adequately generated?
Was allocation adequately concealed?
Blinding Treatment Providers: Was knowledge of the allocated interventions adequately prevented?
Blinding Outcome Assessors: Was knowledge of the allocated interventions adequately prevented?
Blinding Patients: Was knowledge of the allocated interventions adequately prevented?
Was loss to follow-up (missing outcome data) infrequent?
Are reports of the study free of suggestion of selective outcome reporting?
Were outcomes objective, patient-important and assessed in a manner to limit bias (ie. duplicate assessors, Independent assessors)?
Was the sample size sufficiently large to assure a balance of prognosis and sufficiently large number of outcome events?
Was investigator expertise/experience with both treatment and control techniques likely the same (ie.were criteria for surgeon participation/expertise provided)?
はい = 1
不確実=0.5
無関係 = 0
いいえ = 0
報告基準評価では、著者が出版物内で試験の方法論的特徴や試験特性を報告する際の透明性を評価します。評価は以下の5つのカテゴリーに分類されます。
4/4
Randomization
3/4
Outcome Measurements
3/4
Inclusion / Exclusion
2/4
Therapy Description
4/4
Statistics
Detsky AS, Naylor CD, O'Rourke K, McGeer AJ, L'Abbé KA. J Clin Epidemiol. 1992;45:255-65
Fragility Indexは、重要な所見の解釈を助けるツールで、結果の強さの尺度を提供します。Fragility Indexは、その所見が有意でなくなるために、二項対立の結果に追加する必要がある連続した事象の数を表します。数値が小さいほど弱い所見を表し、数値が大きいほど強い所見を表します。
なぜ今この研究が必要なのですか?
Aseptic loosening of tibial components remains a primary concern regarding the overall survivorship of total knee arthroplasty implants. Polyethylene wear has been identified as a potential contributor to aseptic loosening. Recently, there has been debate whether tibial component designs, specifically monoblock versus modular polyethylene components, may differ in their respective wear and migration profiles.
主な研究課題は何ですか?
In total knee arthroplasty, does the use of a monoblock tibial component result in significantly lower component migration within the first 2 years postoperatively when compared to a modular polyethylene component?
重要な知見は?
- There was no significant difference in MTPM between the monoblock group and the modular group after 3 months (0.58mm [95%CI 0.43-0.72] vs. 0.85mm [0.65-1.09]; p=0.2) or 6 months (0.66mm [0.44-0.77] vs. 0.98mm [0.74-1.26];p=0.1); MTPM was significantly lower in the monoblock group compared to the modular group at 12 months (0.65mm [0.46-0.78] vs. 1.01mm [0.81-1.28]; p=0.02) and 24 months (0.72mm [0.53-0.82 vs. 1.15mm [0.90-1.37]; p=0.02).
- In individual axes for translation, no significant differences between groups in anterior-posterior translation or lateral-medial translation of the tibial component were noted at any follow-up. In contrast, beginning at 6 months, significantly smaller superior-inferior translation of the tibial component was observed in the monoblock group compared to the modular group, and significance was maintained after 24 months (-0.18mm [-0.24, -0.07] vs. -0.38mm [-0.54, -0.23]; p=0.02).
- In individual axes for rotation, no significant differences between groups were observed in either anterior-posterior tilt, varus-valgus tilt, or internal-external rotation of the component at any follow-up time point (all p>0.05).
- No significant differences between groups were observed in Knee Society Knee scores, Knee Society Function scores, or EQ-5D scores at any follow-up time point (all p>0.05).
最も覚えておくべきことは?
In uncemented total knee arthroplasty, the use of a monoblock tibial component was associated with significantly smaller maximum total point motion after 24 months, and, specifically, significantly lower superior-inferior translation of the tibial component after 24 months when compared to a modular polyethylene tibial component. No significant between-group differences were noted in x- and z-axis translation of the component, x-, y, and z-axis rotation of the component, or clinical scores after 24 months.
それが私の患者ケアにどのように影響するか?
The results of this study suggest that monoblock tibial components may result in a statistically significantly smaller degree of migration, as assessed via maximum total point motion, from 12 to 24 months after uncemented total knee arthroplasty when compared to modular polyethylene tibial components. Nonetheless, there did not appear to be any clinical impact of the difference observed between groups within this time frame. Follow-up studies are needed to determine if the observed difference in migration has any implication on the incidence of aseptic loosening and component survivorship in the long-term.
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