Comparison of long-term clinical outcomes after bilateral mobile-bearing total knee arthroplasties using PCL-retaining and PCL-substituting implants in the same patients

Total knee arthroplasty using navigation system is known to be more effective than conventional methods in achieving more accurate bone resection and neutral alignment.1 Mobile bearing is also known to reduce wear and automatically correct rotational malalignment of the tibia but the long-term follow-up results of more than 10 years are extremely rare.2, 3 The purpose of this study is to investigate the results of clinical and radiologic long-term follow-up and complications of total knee arthroplasty using navigation and multi-directional mobile bearing.From 2003 to 2006, a total of 111 navigation TKAs using multi-directional mobile bearing design were carried out and reviewed retrospectively. TKAs were performed by two experienced surgeons at one institute. Of the 111 patients, 102 were women and 9 were men. The mean duration of follow-up was 11.4 ± 1.0 years (range, 10.1 to 14.08 years). Clinical outcomes were evaluated in terms of Knee Society Score, Hospital for Special Surgery score, Western Ontario and McMaster University (WOMAC) score, range of motion and complications. Long-term radiological outcomes and survival rates were evaluated at least 10 years.Average preoperative HSS score was 66.5 ± 9.8 and KSS pain and function score were 25.0 ± 11.8 and 44.5 ± 12.3, respectively. Scores improved to 94.1 ± 8.2, 46.6 ± 11.6 and 88.2 ± 14.6 at the last follow up, respectively. Mean preoperative WOMAC scores of 75.8 ± 16.5 improved to 13.8 ± 16.0 at last follow-up. Five knees required re-operation, two for liner breakage, one for liner wear, one for distal femoral fracture and one for infection. The estimated 10-year prosthesis survival rates for any reason and for prosthesis-related problems were 95.5% and 97.4% , respectively.TKAs using each techniques resulted in similar good clinical outcomes and postoperative leg alignments. Robotic and navigation TKA appeared to reduce the number of postoperative leg alignment outliers and revision rate compared to conventional TKA.

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Superior Mid- to Long-Term Clinical Outcomes of Mobile-Bearing Total Knee Arthroplasty Compared to Fixed-Bearing: A Meta-analysis Based on a Minimum of 5 Years of Study

The Journal of Knee Surgery ◽

10.1055/s-0040-1709490 ◽

2020 ◽

Author(s):

Kaiyang Wang ◽

Fang Fang Zhang ◽

Xu Yan ◽

Yifan Shen ◽

Weijie Cai ◽

...

Keyword(s):

Total Knee Arthroplasty ◽

Clinical Outcomes ◽

Knee Arthroplasty ◽

Knee Society Score ◽

Meta Analysis ◽

Mobile Bearing ◽

Fixed Bearing ◽

Total Knee ◽

Standardized Mean Difference

AbstractAs more patients undergo total knee arthroplasty (TKA) each year, and the average age of patients gets younger, the patients are generally more active requiring a greater physiological demand and increasing range of motion on the prosthesis than the previous patients. However, there is no consensus on the optimal TKA tibial bearing design. We performed this systematic review to compare the clinical differences between mobile and fixed bearing constructs used in contemporary TKA. We searched PubMed, EMBASE, and Cochrane Library databases, identifying 515 total publications, including 17 randomized controlled trials (RCTs). A meta-analysis was performed, while the quality and bias of the evidence were rated according to the Grading of Recommendations Assessment Development and Evaluation (GRADE) guidelines and the Cochrane Database questionnaire. The meta-analysis was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Seventeen studies were included, with a total of 1505 knees receiving a mobile bearing TKA and 1550 knees receiving a fixed bearing TKA. The meta-analysis compared clinical outcomes between mobile bearing (MB)-TKA and fixed bearing (FB)-TKA using postoperative Knee Society Score, postoperative ROM, and survivorship and showed that there was a distinct difference in Knee Society Score between the mobile-bearing and fixed-bearing groups (overall standardized mean difference = 1.38; 95% confidence interval (CI): 0.50–2.25; p = 0.002; I2 = 60%). Patients treated with mobile-bearing prostheses were more likely to report good or excellent range of motion results (overall standardized mean difference = 2.06; 95% CI: 0.65–3.47; p = 0.004). No difference in implant survivorship or reoperation rate were identified. The fixed-bearing and mobile-bearing TKA designs are both capable of producing excellent long-term results with excellent clinical outcomes if properly implanted; however, the mobile-bearing TKA have superiority in mid- to long-term clinical results. Trial registration number for PROSPERO was CRD42019126402.

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