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Trabecular metal tibial knee component still stable at 10 years

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ABSTRACT

Background and purpose: Total knee replacement (TKR) in younger patients using cemented components has shown inferior results, mainly due to aseptic loosening. Excellent clinical results have been reported with components made of trabecular metal (TM). In a previous report, we have shown stabilization of the TM tibial implants for up to 5 years. In this study, we compared the clinical and RSA results of these uncemented implants with those of cemented implants.

Patients and methods: 41 patients (47 knees) aged ≤ 60 years underwent TKR. 22 patients (26 knees) received an uncemented monoblock cruciate-retaining (CR) tibial component (TM) and 19 patients (21 knees) received a cemented NexGen Option CR tibial component. Follow-up examination was done at 10 years, and 16 patients (19 knees) with TM tibial components and 17 patients (18 knees) with cemented tibial components remained for analysis.

Results: 1 of 19 TM implants was revised for infection, 2 of 18 cemented components were revised for knee instability, and no revisions were done for loosening. Both types of tibial components migrated in the first 3 months, the TM group to a greater extent than the cemented group. After 3 months, both groups were stable during the next 10 years.

Interpretation: The patterns of migration for uncemented TM implants and cemented tibial implants over the first 10 years indicate that they have a good long-term prognosis regarding fixation

No MeSH data available.


Maximum subsidence of the tibial component in the 2 groups with postoperative and 3-month examinations as reference. Mean with 95% CI (whiskers).
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Figure 0001: Maximum subsidence of the tibial component in the 2 groups with postoperative and 3-month examinations as reference. Mean with 95% CI (whiskers).

Mentions: At 10 years, the TM implants showed statistically significantly more rotation around the x- and y-axes, and significantly more translation measured as maximum subsidence and MTPM.In contrast, the NG implants showed greater maximum lift-off, whereas there was no difference between the groups in z- axis rotation (Table 2 and Table 3, see Supplementary data). However, as was shown already in the 5-year follow-up (Henricson et al. 2013), nearly all migration in both groups occurred within the initial 3 months with stabilization thereafter. We therefore calculated the migration at 10 years using the 3-month examination as reference (Table 4). There were no statistically significant differences between the groups except for subsidence: with a median difference in subsidence of 0.10 mm (95% CI: 0.01–0.17; p < 0.02) (Table 5, and Figures 1 and 2). 1 TM tray showed an MTPM of more than 0.2 mm between 1 and 2 years (Ryd et al. 1995). It stabilized thereafter, and showed a change in MTPM between 2 and 5 years of only 0.03 mm, and between 2 and 10 years of 0.07 mm. No TM implants showed a change in MTPM of more than 0.3 mm between 2 and 5 years, or between 2 and 10 years. In the NexGen cemented group, no implants showed MTPM of more than 0.2 mm between 1 and 2 years. One implant had MTPM of more than 0.3 between 2 and 5 years, and 3 implants had MTPM of more than 0.3 mm between 2 and 10 years.


Trabecular metal tibial knee component still stable at 10 years
Maximum subsidence of the tibial component in the 2 groups with postoperative and 3-month examinations as reference. Mean with 95% CI (whiskers).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5016910&req=5

Figure 0001: Maximum subsidence of the tibial component in the 2 groups with postoperative and 3-month examinations as reference. Mean with 95% CI (whiskers).
Mentions: At 10 years, the TM implants showed statistically significantly more rotation around the x- and y-axes, and significantly more translation measured as maximum subsidence and MTPM.In contrast, the NG implants showed greater maximum lift-off, whereas there was no difference between the groups in z- axis rotation (Table 2 and Table 3, see Supplementary data). However, as was shown already in the 5-year follow-up (Henricson et al. 2013), nearly all migration in both groups occurred within the initial 3 months with stabilization thereafter. We therefore calculated the migration at 10 years using the 3-month examination as reference (Table 4). There were no statistically significant differences between the groups except for subsidence: with a median difference in subsidence of 0.10 mm (95% CI: 0.01–0.17; p < 0.02) (Table 5, and Figures 1 and 2). 1 TM tray showed an MTPM of more than 0.2 mm between 1 and 2 years (Ryd et al. 1995). It stabilized thereafter, and showed a change in MTPM between 2 and 5 years of only 0.03 mm, and between 2 and 10 years of 0.07 mm. No TM implants showed a change in MTPM of more than 0.3 mm between 2 and 5 years, or between 2 and 10 years. In the NexGen cemented group, no implants showed MTPM of more than 0.2 mm between 1 and 2 years. One implant had MTPM of more than 0.3 between 2 and 5 years, and 3 implants had MTPM of more than 0.3 mm between 2 and 10 years.

View Article: PubMed Central - PubMed

ABSTRACT

Background and purpose: Total knee replacement (TKR) in younger patients using cemented components has shown inferior results, mainly due to aseptic loosening. Excellent clinical results have been reported with components made of trabecular metal (TM). In a previous report, we have shown stabilization of the TM tibial implants for up to 5 years. In this study, we compared the clinical and RSA results of these uncemented implants with those of cemented implants.

Patients and methods: 41 patients (47 knees) aged &le; 60 years underwent TKR. 22 patients (26 knees) received an uncemented monoblock cruciate-retaining (CR) tibial component (TM) and 19 patients (21 knees) received a cemented NexGen Option CR tibial component. Follow-up examination was done at 10 years, and 16 patients (19 knees) with TM tibial components and 17 patients (18 knees) with cemented tibial components remained for analysis.

Results: 1 of 19&thinsp;TM implants was revised for infection, 2 of 18 cemented components were revised for knee instability, and no revisions were done for loosening. Both types of tibial components migrated in the first 3 months, the TM group to a greater extent than the cemented group. After 3 months, both groups were stable during the next 10 years.

Interpretation: The patterns of migration for uncemented TM implants and cemented tibial implants over the first 10 years indicate that they have a good long-term prognosis regarding fixation

No MeSH data available.