Twice cutting method reduces tibial cutting error in unicompartmental knee arthroplasty

Knee Surg Sports Traumatol Arthrosc

Tahara

et al. 2016

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Section: Discussionmentioning

confidence: 74%

“…In a previous study, the outlier ratios of the horizontal cutting error in UKA were 26 % in the coronal plane and 10 % in the sagittal plane [9]. The percentages of outlier cases in UKA were higher than those in total knee arthroplasty (TKA).…”

Section: Discussionmentioning

confidence: 99%

A modified technique to reduce tibial keel cutting errors during an Oxford unicompartmental knee arthroplasty

Knee Surg Sports Traumatol Arthrosc

Tahara

et al. 2016

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“…Femoral drilling was performed with an Oxford Microplasty device (MP: Biomet Ltd., Swindon, UK) to facilitate reproducible implant alignment [ 15 ]. After these procedures, we performed the same gap-balancing procedure between knee flexion and extension and a modified keel cutting method as that previously reported [ 16 , 17 ]. With the trial components in place, we used two candidate trial MBs with a 1-mm thickness difference with the trial components to prospectively investigate the effects of a 1-mm difference in MB thickness.…”

Section: Methodsmentioning

confidence: 99%

Effects of a 1-mm difference in bearing thickness on intraoperative bearing movement and kinematics in Oxford unicompartmental knee arthroplasty

Kawaguchi

BMC Musculoskelet Disord

et al. 2022

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Background The choice of mobile bearing (MB) thickness is essential for obtaining successful results after mobile-bearing Oxford unicompartmental knee arthroplasty (UKA). This study aimed to investigate the effects of a 1-mm difference in bearing thickness on intraoperative MB movement and intraoperative knee kinematics in Oxford UKAs. Methods We prospectively investigated the effects of a 1-mm difference in bearing thickness on intraoperative MB movement and knee kinematics in 25 patients who underwent Oxford UKAs when surgeons didn’t know which bearing thickness to choose with 1-mm difference. A trial tibial component that was scaled every 2 mm was used to measure the intraoperative MB movement, and the tibial internal rotation relative to the femur and the knee varus angle was simultaneously evaluated using the navigation system as the knee kinematics. We separately evaluated sets of two MB thicknesses with 1-mm differences, and we compared the intraoperative parameters at maximum extension; 30º, 45º, 60º, and 90º flexion; and maximum flexion between the thicker MB (thick group) and the thinner MB (thin group). Results The MB in the thin group was located significantly posteriorly at 90º flexion compared with that in the thick group; however, there were no differences at the other flexion angles. There was significantly less tibial internal rotation in the thin group at 90º flexion than that in the thick group; however, there were no differences at the other flexion angles. The knee varus angles in the thick group were significantly smaller than those in the thin group by approximately one degree at all angles other than at 30º and 45º flexion. Conclusion The thicker MB could bring the less posterior MB movement and the more tibial internal rotation at 90º flexion, additionally the valgus correction angle in the thicker MB should be paid attention. These results could help surgeons to decide the thickness of MBs when they wonder the thickness of MB.

“…Femoral drilling was performed using a device to facilitate reproducible femoral implantation [ 21 ]. After completing these procedures, we performed the same gap-balancing procedure between knee flexion and extension and a modified keel cutting method, as reported previously [ 22 ].…”

Section: Methodsmentioning

confidence: 99%

Intraoperative rotational kinematics and its influence on postoperative clinical outcomes differ according to age in Unicompartmental knee Arthroplasty

Kawaguchi

BMC Musculoskelet Disord

et al. 2021

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Background Although Oxford unicompartmental knee arthroplasty (UKA) is used in patients of wide age ranges, there is no clear information regarding the age differences in terms of intraoperative femorotibial rotational kinematics and its influence on clinical outcomes. Therefore, this study was conducted to examine the age differences in terms of intraoperative rotational kinematics and postoperative clinical outcomes and to analyze their relationship with classification according to the age group. Methods We investigated 111 knees of patients who underwent Oxford UKA using a navigation system and divided them into two groups: elderly (aged ≥75 years; 48 knees) and nonelderly (aged < 75 years; 63 knees). Intraoperative tibial internal rotational angles relative to the femur during passive knee flexion were measured using a navigation system, and clinical outcomes were evaluated using knee range of motion, the Knee Injury and Osteoarthritis Outcome Score (KOOS), and the Knee Society Functional Score at 2 years postoperatively. The relationships between intraoperative tibiofemoral rotational angles and clinical outcomes were also evaluated in the two groups. Results The intraoperative tibial internal rotational angle relative to the femur during knee flexion was significantly larger in the nonelderly group (13.5°) than in the elderly group (9.0°). The intraoperative tibial internal rotational angle showed a positive correlation with the pain subscale of KOOS only in the nonelderly group. Conclusion Intraoperative rotational kinematics and its influence on clinical outcomes were different between elderly and nonelderly patients, and the tibial internal rotational angle could be a more important factor for successful UKA in nonelderly patients.