Comparison of clinical and radiographic results between total knee arthroplasties using medial pivot and posterior-stabilized prosthesis: A meta-analysis

Abstract

Objective: To evaluate the clinical and radiographic outcomes of total knee arthroplasties (TKA) between using medial-pivot (MP) and posterior-stabilized (PS) prosthesis. Does MP prosthesis and PS prosthesis influence the clinical results of a TKA?

Methods: An electronic literature search of PubMed Medline and the Cochrane Library was performed from inception to October 1, 2019. A meta-analysis to compare postoperative outcomes of Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, Knee Society Score (KSS), range of motion (ROM), complications, and radiographic results between MP and PS prosthesis were conducted.

Results: Seven eligible studies involving 934 adult patients (MP group, n = 461; PS group, n = 473) were identified for analysis. This study showed no significant difference between the 2 groups in the WOMAC scores, KSS, ROM, and complications (P > .05). The differences of the femorotibial angle, position of implant, and patellar tilt were also not significant between the 2 groups (P > .05).

Conclusion: The present meta-analysis has shown that patients with the MP prosthesis have similar clinical results as patients with PS prosthesis. Furthermore, the radiographic results, especially patella tilt angle, were also similar between the 2 groups. Therefore, surgeons should be aware that the types of prostheses are not a decisive factor to ensure successful operation.

Figure 1

Flow of study selection.

Figure 2

Funnel plot for range of motion.

Figure 3

The MD of the WOMAC score (0–100) was 0.43 (P = .84; 95% CI, –3.76–4.63). There was no significant difference between the MP group and the PS group (P > .05). CI = confidence interval, MD = mean difference, MP = medial pivot, PS = posterior-stabilized, WOMAC = Western Ontario and McMaster Universities Osteoarthritis Index.

Figure 4

The MD of the KKS and KFS were –2.30 (P = .31; 95% CI, –6.77–2.17) and –1.89 (P = .09; 95% CI, –4.10–0.32), respectively. The differences between the MP group and the PS group were not statistically significant (P > .05). CI = confidence interval, KFS = Knee Society Function Score, KKS = Knee Society Knee Score, MD = mean difference, MP = medial pivot, PS = posterior-stabilized.

Figure 5

The MD of the ROM was –1.68 (P = .37; 95% CI, –5.34–1.98). There was no significant difference between the MP group and the PS group (P > .05). CI = confidence interval, MD = mean difference, MP = medial pivot, PS = posterior-stabilized, ROM = range of motion.

Figure 6

The MD of the femorotibial angle was –0.14 (P = .73; 95% CI, –0.97–0.69). There was no significant difference between the MP group and the PS group (P > .05). CI = confidence interval, MD = mean difference, MP = medial pivot, PS = posterior-stabilized.

Figure 7

The MD of the α angle, β angle, γ angle, and δ angle were 0.08 (P = .89; 95% CI, –1.11–1.28), 0.04 (P = .82; 95% CI, –0.31–0.40), 0.37 (P = .82; 95% CI, –2.77–3.52), and 0.55 (P = .11; 95% CI, –0.12–1.21), respectively. The differences between the MP group and the PS group were not statistically significant (P > .05). CI = confidence interval, MD = mean difference, MP = medial pivot, PS = posterior-stabilized.

Figure 8

The MD of the patella tilt angle was 1.95 (P = .06; 95% CI, –0.08–3.98). There was no significant difference between the MP group and the PS group (P > .05). CI = confidence interval, MD = mean difference, MP = medial pivot, PS = posterior-stabilized.

Figure 9

There was no significantly greater proportion of the complications in the MP group and the PS group during the minimum follow-up period (RR = 1.35; P = .56; 95% CI, 0.49–3.71), (P > .05). CI = confidence interval, MP = medial pivot, PS = posterior-stabilized, RR = risk ratio.