Summary of findings for the main comparison. Mobile bearing vs fixed bearing prosthesis for posterior cruciate retaining total knee arthroplasty for postoperative functional status in patients with osteoarthritis and rheumatoid arthritis.
| Mobile bearing vs fixed bearing prosthesis for posterior cruciate retaining total knee arthroplasty for postoperative functional status in patients with osteoarthritis and rheumatoid arthritis | ||||||
| Patient or population: patients with posterior cruciate retaining total knee arthroplasty for postoperative functional status in patients with osteoarthritis and rheumatoid arthritis Settings: hospital Intervention: fixed bearing Comparison: mobile bearing | ||||||
| Outcomes | Illustrative comparative risks* (95% CI) | Relative effect (95% CI) | Number of participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Assumed risk | Corresponding risk | |||||
| Mobile bearing | Fixed bearing | |||||
| Pain ‐ measured as KSS pain Knee Society Score, subscore pain. Scale from 0 (severe pain) to 50 (no pain) Follow‐up: 1‐10.8 years | Mean SMD in the mobile bearing groups was 41.4 points | Standardised mean pain score in the fixed bearing groups was 0.09 higher (‐0.03 lower to 0.22 higher) | 1531 knees (68%) (11 studies, 58%) | ⊕⊕⊕⊝ Moderatea | Transformed into Knee Society score, subscore pain (range 0 to 50) Absolute difference: 2.4% higher (‐0.08% to 5.9%) Relative percent change: 0.22% (‐0.07% to 0.53% higher) Not statistically significant |
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| Function ‐ measured as KSS function Knee Society Score, function. Scale from 0 to 100 (higher scores indicates better function) Follow‐up: 0.5‐10.8 years | Mean KSS function in the mobile bearing groups was 84.5 points | Mean KSS function in the fixed bearing groups was 0.1 lower (1.93 lower to 1.73 higher) | 1865 knees (83%) (14 studies, 74%) | ⊕⊕⊝⊝ Lowa,b | Absolute difference: 0.1% higher (‐1.93% to 1.73%) Relative percent change: 0.1% (‐2.28% to 2.05% higher) Not statistically significant |
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| Health‐related quality of life ‐ measured as SF‐12 PCS SF‐12 PCS. Scale from 0 to 100 (higher scores indicate better health‐related quality of life) Follow‐up: 2‐2.5 years | Mean SF‐12 PCS in the mobile bearing groups was 42.3 points | Mean SF‐12 PCS in the fixed bearing groups was 1.96 lower (4.55 lower to 0.63 higher) | 498 knees (22%) (3 studies, 16%) | ⊕⊕⊝⊝ Lowa,b | Absolute difference: 1.96% lower (‐4.55% to 0.63%) Relative percent change: 4.63% (‐10.75% to 1.49% higher) Not statistically significant |
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| Revision surgery Follow‐up: 1‐9.8 years | 14 per 1000 | 11 per 1000 (4 to 24) | See comment RR 0.80 (0.26‐1.74) |
2065 knees (92%) (17 studies) | ⊕⊕⊝⊝ Lowa,c | Risks were calculated from pooled risk differences Absolute risk difference: 0.00 (‐0.01 to 0.01) Relative percent change: 20% (I) (74% (W) to 74% (I) Not statistically significant |
| Mortality Follow‐up: 1‐2 years | 33 per 1000 | 22 per 1000 (‐18 to 58) | See comment RR 0.69 (‐0.55‐1.78) |
188 persons (12%) (4 studies) | ⊕⊕⊝⊝ Lowa,c | Risks were calculated from pooled risk differences Absolute risk difference: 0.02 lower (‐0.06 to 0.03) Relative percent change: 31% (I) (211% (W) to 78% (I) Not statistically significant |
| Reoperation rate Follow‐up: 1‐9.8 years | 12 per 1000 | 12 per 1000 (2 to 22) | See comment RR 1.01 (0.14‐1.86) |
2065 (92%) (17 studies) | ⊕⊕⊝⊝ Lowa,c | Risks were calculated from pooled risk differences Absolute risk difference 0.01 lower (‐0.01 to 0.01) Relative percent change: 1% (h) (86% (W) to 86% (I) Not statistically significant |
| Other serious adverse events Follow‐up: 1‐9.8 years | 6 per 1000 | 7 per 1000 (3 to 11) | See comment RR 1.16 (0.44‐1.84) |
1732 knees (77%) (17 studies) | ⊕⊕⊝⊝ Lowa,c | Risks were calculated from pooled risk differences Absolute risk difference: 0.00 (‐0.01 to 0.01) Relative percent change: 16% (h) (56% (W) to 84% (I) Not statistically significant |
| *The basis for the assumed risk (e.g. median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval; RR: Risk ratio. | ||||||
| GRADE Working Group grades of evidence. High quality: Further research is very unlikely to change our confidence in the estimate of effect. Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. Very low quality: We are very uncertain about the estimate. | ||||||
aRisk of bias in individual studies, see 'Risk of bias' tables. bHeterogeneity is present. cTotal number of events is less than 300.