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: Variety of clinical trials have been published comparing the alignment of MICA-UKA with MI-UKA. However, to the best of our knowledge, no published study has showed whether radiological alignment by MICA-UKA has influence on the clinical results. The present study was conducted to compare the short-term results of MICA-UKA with MI-UKA. It was hypothesized that better alignment as well as clinical results was achieved by MICA-UKA as compared to MI-UKA. The clinical and radiological results of 87 subjects who underwent primary UKA using either minimally invasive and computer-assisted technique (45 patients Group A) or minimally invasive technique (42 patients, Group B) were reported. Knee Society scores (KSSs), Knee Society functional scores (KSFSs), range of motion (ROM), and radiographic results were assessed and reported preoperatively and at 24-month follow-up. Total blood loss, operative time, and length of skin incision were compared. The accuracy of the implantations in relation to the coronal mechanical axis in Group A was significantly superior to that of Group B (P = 0.033). The femoral rotational profile revealed the prosthesis in Group A that was implanted with significantly less internal rotation than Group B (P = 0.025). Clinical results, with regard to ROMs and KSSs, as well as KSFSs were equally good in both the groups. The average blood loss in patients of Group A was significantly reduced as compared to patients of Group B. No significant difference was detected in terms of operative time or length of skin incision. It is suggested that MICA-UKA improves the implant alignment without increasing clinical results versus MI-UKA. We advocate that computer navigation should be considered when minimally invasive unicompartmental knee arthroplasty is performed. Therapeutic study, Level II.
    Knee Surgery Sports Traumatology Arthroscopy 11/2014; DOI:10.1007/s00167-014-3456-9 · 2.84 Impact Factor
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    ABSTRACT: Background Surgical robotics has been shown to improve the accuracy of bone preparation and soft tissue balance in unicondylar knee arthroplasty (UKA). However, although extensive data have emerged with regard to a CT scan-based haptically constrained robotic arm, little is known about the accuracy of a newer alternative, an imageless robotic system. Questions/purposes We assessed the accuracy of a novel imageless semiautonomous freehand robotic sculpting system in performing bone resection and preparation in UKA using cadaveric specimens. Methods In this controlled study, we compared the planned and final implant placement in 25 cadaveric specimens undergoing UKA using the new tool. A quantitative analysis was performed to determine the translational, angular, and rotational differences between the planned and achieved positions of the implants. Results The femoral implant rotational mean error was 1.04° to 1.88° and mean translational error was 0.72 to 1.29 mm across the three planes. The tibial implant rotational mean error was 1.48° to 1.98° and the mean translational error was 0.79 to 1.27 mm across the three planes. Conclusions The image-free robotic sculpting tool achieved accurate implementation of the surgical plan with small errors in implant placement. The next step will be to determine whether accurate implant placement translates into a clinical and functional benefit for the patient.
    Clinical Orthopaedics and Related Research 07/2014; 473(1). DOI:10.1007/s11999-014-3764-x · 2.88 Impact Factor
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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; 22(9). DOI:10.1016/j.joca.2014.07.006 · 4.66 Impact Factor


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May 16, 2014