Does new instrument for Oxford unicompartmental knee arthroplasty improve short-term clinical outcome and component alignment? A meta-analysis

Sun, Xiao Wei; Lu, Fei Fan; Zou, Kun; Hong, Mao; Zhang, Qi Dong; Guo, Wenjuan

doi:10.1186/s13018-020-01926-w

Cited by 6 publications

(11 citation statements)

References 22 publications

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“…The microplasty instrumentation, which was introduced after the OUKRs in this study were implanted and is now routinely used, was designed to make the operation simpler and more reproducible. Several studies have shown that microplasty improves component positioning [34][35][36][37] and decreases the rate of bearing dislocation [38]. It includes instrumentation to accurately determine the height of the tibial cut, which facilitates selecting a Size 4 bearing in young active patients.…”

Section: Discussionmentioning

confidence: 99%

Polyethylene bearing wear is comparable for cemented and cementless Oxford unicompartmental knee replacements: Ten‐year results of a randomized controlled trial

Arthur,

Ghosh,

Mohammad

et al. 2024

Knee surg. sports traumatol. arthrosc.

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PurposeThere is concern that using cementless components may increase polyethylene wear of the Oxford unicompartmental knee replacement (OUKR). Therefore, this study aimed to measure bearing wear at 10 years in patients from a randomized trial comparing Phase 3 cemented and cementless OUKRs and to investigate factors that may affect wear. It was hypothesized that there would be no difference in wear rate between cemented and cementless OUKRs.MethodsBearing thickness was determined using radiostereometric analysis at postoperative, 3‐month, 6‐month, 1‐year, 2‐year, 5‐year and 10‐year timepoints. As creep occurs early, wear rate was calculated using linear regression between 6 months and 10 years for 39 knees (20 cemented, 19 cementless). Associations between wear and implant, surgical and patient factors were analysed.ResultsThe linear wear rate of the Phase 3 OUKR was 0.06 mm/year with no significant difference (p = 0.18) between cemented (0.054 mm/year) and cementless (0.063 mm/year) implants. Age, Oxford Knee Score, component size and bearing thickness had no correlation with wear. A body mass index ≥ 30 was associated with a significantly lower wear rate (p = 0.007) as was having ≥80% femoral component contact area on the bearing (p = 0.003). Bearings positioned ≥1.5 mm from the tibial wall had a significantly higher wear rate (p = 0.002).ConclusionsAt 10 years, the Phase 3 OUKR linear wear rate is low and not associated with the fixation method. To minimize the risk of wear‐related bearing fracture in the very long‐term surgeons should consider using 4 mm bearings in very young active patients and ensure that components are appropriately positioned, which is facilitated by the current instrumentation.Level of EvidenceLevel III, Retrospective Comparative Study.

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Section: Discussionmentioning

confidence: 99%

Polyethylene bearing wear is comparable for cemented and cementless Oxford unicompartmental knee replacements: Ten‐year results of a randomized controlled trial

Arthur,

Ghosh,

Mohammad

et al. 2024

Knee surg. sports traumatol. arthrosc.

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“…The new Oxford Microplasty instruments were introduced along with the cemented Oxford Partial and uncemented Oxford Partial to improve the reproducibility of implant positioning and to minimize tibial bone resection. Two studies comparing Oxford Microplasty to conventional instrumentation showed a reduced risk of malalignment of the femoral component and more accurate tibial bone resection, with less bone loss [21,22]; another study reported reduced revision rates with the new instrumentation [20]. This new instrument set, mostly used for the newest designs, may have influenced the results in favor of the Oxford partial prostheses.…”

Section: Did the Indications For Revision Change Between The Older An...mentioning

confidence: 99%

Did a New Design of the Oxford Unicompartmental Knee Prosthesis Result in Improved Survival? A Study From the Norwegian Arthroplasty Register 2012-2021

Skåden

Furnes

Lygre

et al. 2023

Clin Orthop Relat Res

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Background Unicompartmental knee arthroplasty (UKA) has generally shown higher revision rates than TKA, and this is particularly true for the femoral component. A twin-peg femoral component (Oxford Partial) has replaced the single-peg version (Oxford Phase III) of the widely used Oxford medial UKA, with the aim of improving femoral component fixation. The introduction of the Oxford Partial Knee also included a fully uncemented option. However, there has been relatively little evidence regarding the effect of these changes on implant survival and revision diagnoses from groups not associated with the implant design. Questions/purposes Using data from the Norwegian Arthroplasty Register, we asked: (1) Has the 5-year implant survival (free from revision for any cause) improved with the medial Oxford unicompartmental knee after the introduction of new designs? (2) Did the causes of revision change between the old and new designs? (3) Is there a difference in risk for specific revision causes between the uncemented and cemented versions of the new design? Methods We performed a registry-based observational study using data from the Norwegian Arthroplasty Register, a nationwide, mandatory and governmental registry with a high reporting rate. Between 2012 and 2021, 7549 Oxford UKAs were performed, and 105 were excluded due to combinations of the three designs, lateral compartment replacement, or hybrid fixation, leaving 908 cemented Oxford Phase III single-peg (used from 2012 to 2017), 4715 cemented Oxford Partial twin-peg (used from 2012 to 2021), and 1821 uncemented Oxford Partial twin-peg (used from 2014 to 2021), UKAs available for the analysis. The Kaplan-Meier method and Cox regression multivariate analysis were used to find the 5-year implant survival and the risk of revision (hazard ratio), when adjusting for age, gender, diagnosis, American Society of Anesthesiologists grade, and time period. The risk of revision for any cause and the risk of revision for specific causes were compared, first for the older with the two new designs, and second for the cemented with the uncemented version of the new design. Revision was defined as any operation exchanging or removing implant parts. Results The 5-year Kaplan-Meier overall implant survival (free from revision for any cause) for the medial Oxford Partial unicompartmental knee did not improve over the study period. The 5-year Kaplan-Meier survival was different (p = 0.03) between the groups: it was 92% (95% confidence interval [CI] 90% to 94%) for the cemented Oxford III, 94% (95% CI 93% to 95%) for the cemented Oxford Partial, and 94% (95% CI 92% to 95%) for the uncemented Oxford Partial. However, the overall risk of revision during the first 5 years was not different between the groups (Cox regression HR 0.8 [95% CI 0.6 to 1.0]; p = 0.09 and 1.0 [95% CI 0.7 to 1.4]; p = 0.89 for the cemented Oxford Partial and the uncemented Oxford Partial, respectively, compared with cemented Oxford III [HR 1]). The uncemented Oxford Partial had a higher risk of revision for infection (HR 3.6 [95% CI 1.2 to 10.5]; p = 0.02) compared with the cemented Oxford III. The uncemented Oxford Partial had a lower risk of revision for pain (HR 0.5 [95% CI 0.2 to 1.0]; p = 0.045) and instability (HR 0.3 [95% CI 0.1 to 0.9]; p = 0.03) compared with the cemented Oxford III. The cemented Oxford Partial had a lower risk of revision for aseptic femoral loosening (HR 0.3 [95% CI 0.1 to 1.0]; p = 0.04) compared with the cemented Oxford III. When comparing the uncemented and cemented versions of the new design, the uncemented Oxford Partial had a higher risk of revision for periprosthetic fracture (HR 15 [95% CI 4 to 54]; p = 0.001) and infection within the first year (HR 3.0 [95% CI 1.5 to 5.7]; p = 0.001) than the cemented Oxford Partial. Conclusion Considering that we found no difference in overall risk of revision during the first 5 years but we found a higher risk of revision for infection, periprosthetic fracture, and higher per implant cost, we currently would recommend against the use of uncemented Oxford Partial over the cemented Oxford Partial or the cemented Oxford III. Level of Evidence Level III, therapeutic study

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“…Currently, most MB-UKA procedures are performed by using Microplasty instruments [12]. Tibial osteotomy is performed rst, followed by femoral drilling.…”

Section: Introductionmentioning

confidence: 99%

The varus/valgus angle of the femoral component relative to the tibial component can lead to a deviation of the bearing position in mobile bearing unicompartmental knee arthroplasty which can increase the risk of bearing dislocation

2024

Preprint

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Purpose: This study aimedto evaluate the relationship between the bearing position and relative angle of the femoral and tibial components using postoperative radiological measurements. Methods: This study included 120 patients who underwent MB-UKA at our hospital between January and August 2023. Standard anteroposterior-view radiographs were obtained postoperatively using C-arm fluoroscopy. We developed a 3D-2D image matching method to measure the femoral component varus/valgus angle and internal/external rotation (IR/ER) relative to the tibial component. The bearing position parameters were measured. Patients were divided into varus/valgus groups and IR/ER groups according to the femoral component varus/valgus angle and IR/ER angle. The bearing position parameters of each group were compared separately. Results: There were 57 patients in the varus group, 63 in the valgus group, 59 in the IR group, and 61 in the ER group. The W-BED (the distance between the bearing lateral edge and the lateral wall) was significantly lower in varus group than in the valgus group (1.9 (0 to 6.4) vs 2.8 (0.3 to 7.7) mm; P<0.001). No differences were observed in any bearing position parameters. The varus/valgus angle of the femoral component showed a significant negative correlation with the W-BED. The IR/ER angle of the femoral component showed no significant correlation with any of the positional parameters. Conclusion: The varus/valgus angle of the femoral component relative to the tibial component can lead to a deviation of the bearing position. The IR/ER of the femoral component had no effect on the final bearing position.

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Does new instrument for Oxford unicompartmental knee arthroplasty improve short-term clinical outcome and component alignment? A meta-analysis

Cited by 6 publications

References 22 publications

Polyethylene bearing wear is comparable for cemented and cementless Oxford unicompartmental knee replacements: Ten‐year results of a randomized controlled trial

Polyethylene bearing wear is comparable for cemented and cementless Oxford unicompartmental knee replacements: Ten‐year results of a randomized controlled trial

Did a New Design of the Oxford Unicompartmental Knee Prosthesis Result in Improved Survival? A Study From the Norwegian Arthroplasty Register 2012-2021

The varus/valgus angle of the femoral component relative to the tibial component can lead to a deviation of the bearing position in mobile bearing unicompartmental knee arthroplasty which can increase the risk of bearing dislocation

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