Unicompartmental knee arthroplasty relieves pain and improves function more than total knee arthroplasty.

Center for Hip and Knee Replacement, New York–Presbyterian Hospital at Columbia University, New York, New York 10032, USA.
The Journal of arthroplasty (Impact Factor: 2.37). 05/2012; 27(8 Suppl):99-105. DOI: 10.1016/j.arth.2012.03.044
Source: PubMed

ABSTRACT This study compared outcomes as assessed by 12-item Short-Form Health Survey (SF-12) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) between patients who underwent unicompartmental (UKA) and patients who underwent total knee (TKA) arthroplasty. We prospectively collected preoperative demographic and SF-12 and WOMAC data on 128 TKAs and 70 UKAs. Postoperatively, SF-12 and WOMAC outcomes were recorded during annual follow-up visits. At baseline, patients who underwent UKA had a higher Charlson Comorbidity Index than patients who underwent TKA; otherwise, preoperative characteristics were similar. At a mean follow-up of 3.0 years for UKA and 2.9 years for TKA, patients who underwent UKA reported higher SF-12 physical component and mental component scores and WOMAC pain/stiffness/physical function scores (confirmed with multivariate analysis). Furthermore, patients who underwent UKA had significantly larger improvements in both SF-12 outcomes and WOMAC pain and physical function scores from baseline than did patients who underwent TKA.

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    ABSTRACT: Objective Unicompartmental Knee Replacement (UKR) has important advantages over total knee replacement (TKR) but has a higher revision rate. Outcomes vary between centres, suggesting that risk factors for revision may be modifiable with changes to patient selection or operative technique. The objective of this study was to determine factors affecting revision, patient-reported outcome and satisfaction following UKR. Method 25,982 cases from three national databases were analysed. Multilevel multivariable regression models were used to examine the effect of patient and surgical factors on implant survival, patient-reported outcome and satisfaction at six months and eight years following UKR. Results Of the 25,982 cases, 3,862 (14.9%) had pre-operative and six-month Oxford Knee Scores (OKS). Eight-year survival was 89.1% (95% CI 88.3-89.9). OKS increased from 21.9 (SD 7.6) to 37.5 (SD 9.5). Age (HR 0.96 (95%CI 0.96-0.97) per year), male gender (HR 0.86 (95%CI 0.76-0.96)), unit size (HR 0.92 (95%CI 0.86-0.97) per case up to 40 cases/year) and operating surgeon grade (HR 0.78 (95%CI 0.67-0.91) if consultant) predicted improved implant survival. Older patients (≤75 years), and those with lower deprivation levels had superior OKS and satisfaction (adjusted mean difference 0.14 (95%CI 0.09-0.20) points per year of age and 0.93 (95%CI 0.60-1.27) per quintile of deprivation). Ethnicity, anxiety and co-morbidities also affected patient-reported outcome. Conclusions This study has identified important predictors of revision and patient-reported outcome following UKR. Older patients, who are least likely to be offered UKR, may derive the greatest benefits. Improved understanding of these factors may improve the long-term outcomes of UKR.
    Osteoarthritis and Cartilage 09/2014; · 4.66 Impact Factor
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    ABSTRACT: Unicompartmental knee arthroplasty (UKA) is a reliable operation for isolated unicompartmental arthritis. A comprehensive understanding of the limitations of UKA is crucial for success in the young patient. Obesity may impact implant longevity; however, acceptable results can be achieved with precise component implantation and careful patient selection. UKA for degenerative medial compartment arthritis with attritional anterior cruciate ligament (ACL) rupture is generally contraindicated. However, concomitant ACL/UKA reconstruction is a dependable treatment for early posterior-medial compartment arthritis caused by an acute ACL rupture. Regardless of its limitations, the functional benefits and limited morbidity of UKA make it an appealing treatment option for unicompartmental disease.
    Clinics in sports medicine 01/2014; 33(1):11-21. · 1.33 Impact Factor
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    ABSTRACT: Introduction In several recent studies, unicompartmental knee arthroplasty (UKA) produced better functional outcomes than did total knee arthroplasty with 10-year prosthesis survival rates greater than 95%. Nevertheless, UKA is still widely viewed as producing inconsistent results. Tibial component loosening is the leading cause of failure. We consequently sought to identify tibial component position criteria associated with outcomes of medial UKA. Material and methods We conducted a retrospective multicentre study of 559 medial UKAs performed between 1988 and 2010 in 421 patients (262 females and 159 males) with a mean age of 69.51 ± 8.72 years at surgery. We recorded the following radiographic parameters: joint space height, obliquity and slope of the tibial implant, whether the tibial component was perpendicular to the femoral component, and lower limb malalignment. The International Knee Society (IKS) score was used to assess clinical outcomes. Mean follow-up at re-evaluation was 5.17 ± 4.33 years. Results The mean 10-year prosthesis survival rate was 83.7 ± 3.5%. Factors associated with decreased prosthesis survival were a greater than 2-mm change in joint space height, a greater than 3° change in tibial component obliquity, a slope value greater than 5° or a change in slope greater than 2°, and more than 6° of divergence between the tibial and femoral components. Residual mechanical varus of 5° or more was also associated with mechanical failure. The only factor associated with worse functional score values was joint space elevation by more than 2 mm. Discussion The high level of accuracy required for optimal positioning of the tibial component during medial UKA indicates a need for considerable technical expertise and emphasises the conservative nature of the procedure. Optimal positioning is crucial to restore normal knee kinematics and to prevent implant wear and lesions to adjacent compartments. Level of evidence IV, retrospective study.
    Orthopaedics & Traumatology Surgery & Research 04/2013; 99(4):S219–S225. · 1.17 Impact Factor


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May 16, 2014