Kinematic alignment technique for medial OXFORD UKA: An in-silico study

Rivière, Charles; Harman, Ciara; Leong, Anthony; Cobb, Justin P.; Maillot, Cédric

doi:10.1016/j.otsr.2018.11.005

Cited by 23 publications

(15 citation statements)

References 25 publications

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“…The application of an individualized alignment approach, guided by re‐tensioning of the MCL, has been shown to restore both joint line obliquity and the mechanical axis to its pre‐arthritic state following medial UKA for medial compartment OA [1]. Theoretically, restoration of the natural soft tissue envelope and knee kinematics may translate into reduced postoperative stiffness, better load distribution, and subsequently improved functional outcomes and survivorship [23, 27, 36]. However, supportive evidence on the clinical relevance of a pre‐arthritic alignment strategy remained scarce.…”

Section: Discussionmentioning

confidence: 99%

Restoration or relative overcorrection of pre-arthritic coronal alignment leads to improved results following medial unicompartmental knee arthroplasty

Bayoumi

Burger

Ruderman

et al. 2023

Knee Surg Sports Traumatol Arthrosc

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PurposeA pre‐arthritic alignment strategy for medial unicompartmental knee arthroplasty (UKA) aims to restore a patient’s native lower limb alignment which may translate into improved outcomes. This study aimed to assess whether patients with pre‐arthritically aligned knees versus patients with non‐pre‐arthritically aligned knees demonstrated improved mid‐term outcomes and survivorship following medial UKA. The hypothesis was that pre‐arthritic alignment in medial UKA would lead to better postoperative outcomes. MethodsA retrospective study of 537 robotic‐assisted fixed‐bearing medial UKA was conducted. During this procedure, the surgical goal was to restore pre‐arthritic alignment guided by re‐tensioning of the medial collateral ligament (MCL). For study purposes, coronal alignment was retrospectively evaluated using the mechanical hip‐knee‐ankle angle (mHKA). Pre‐arthritic alignment was estimated through the arithmetic hip‐knee‐ankle (aHKA) algorithm. Knees were grouped according to the difference between postoperative mHKA and estimated pre‐arthritic alignment (i.e., mHKA ‐ aHKA) as Group 1 (pre‐arthritically aligned: mHKA restored within 2.0° of the aHKA), Group 2 (mHKA > 2.0° overcorrected relative to the aHKA), or Group 3 (mHKA > 2.0° undercorrected relative to the aHKA). Outcomes included the Knee Injury and Osteoarthritic Outcome Score for Joint Replacement (KOOS, JR), Kujala, proportions of knees achieving the patient acceptable symptom state (PASS) for these scores, and survivorship. PASS thresholds for KOOS, JR and Kujala were determined using a receiver operating characteristic curve method. ResultsA total of 369 knees were categorized as Group 1, 107 as Group 2, and 61 as Group 3. At 4.4 ± 1.6 years follow‐up, mean KOOS, JR was comparable among groups, while Kujala was significantly worse in Group 3. The proportion of knees achieving the PASS for Kujala (76.5 points) was lower in Group 3 (n = 32; 59%) compared to Group 1 (n = 260; 74%) (p = 0.02). 5‐year survivorship was higher in Group 1 and Group 2 (99% and 100%, respectively) compared to Group 3 (91%) (p = 0.04). ConclusionPre‐arthritically aligned knees and knees with relative overcorrection from their pre‐arthritic alignment following medial UKA demonstrated improved mid‐term outcomes and survivorship compared to knees with relative under correction from their pre‐arthritic alignment. These results encourage restoring or relatively overcorrecting pre‐arthritic alignment to optimize outcomes following medial UKA, and caution against under correction from the pre‐arthritic alignment. Level of evidenceIV, case series.

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Section: Discussionmentioning

confidence: 99%

Restoration or relative overcorrection of pre-arthritic coronal alignment leads to improved results following medial unicompartmental knee arthroplasty

Bayoumi

Burger

Ruderman

et al. 2023

Knee Surg Sports Traumatol Arthrosc

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“…On the other hand, few reports have been available regarding the tibia alignment in the coronal plane. Rivière et al 35 conducted the computer simulation study and revealed that a varus aligned tibial tray in Oxford UKA showed better adaptation than mechanical aligned (perpendicular to the tibial axis) tray. Dai et al 36 reported that a slight varus implantation of the Oxford tibial tray reduced the peak stress on the medial cortex in a 3-D finite element analysis study.…”

Section: Discussionmentioning

confidence: 99%

Tibial shape and size predicts the risk of tibial plateau fracture after cementless unicompartmental knee arthroplasty in Japanese patients

Hiranaka

Yoshikawa

Yoshida

et al. 2020

The Bone & Joint Journal

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Aims Cementless unicompartmental knee arthroplasty (UKA) has advantages over cemented UKA, including improved fixation, but has a higher risk of tibial plateau fracture, particularly in Japanese patients. The aim of this multicentre study was to determine when cementless tibial components could safely be used in Japanese patients based on the size and shape of the tibia. Methods The study involved 212 cementless Oxford UKAs which were undertaken in 174 patients in six hospitals. The medial eminence line (MEL), which is a line parallel to the tibial axis passing through the tip of medial intercondylar eminence, was drawn on preoperative radiographs. Knees were classified as having a very overhanging medial tibial condyle if this line passed medial to the medial tibial cortex. They were also classified as very small if a size A/AA tibial component was used. Results The overall rate of fracture was 8% (17 out of 212 knees). The rate was higher in knees with very overhanging condyles (Odds ratio (OR) 13; p < 0.001) and with very small components (OR 7; p < 0.001). The OR was 21 (p < 0.001) in those with both very overhanging condyles and very small components. In all, 69% of knees (147) had neither very overhanging nor very small components, and the fracture rate in these patients was 1.4% (2 out of 147 knees). Males had a significantly reduced risk of fracture (OR 0.13; p = 0.002), probably because no males required very small components and females were more likely to have very overhanging condyles (OR 3; p = 0.013). 31% of knees (66) were in males and in these the rate of fracture was 1.5% (1 out of 66 knees). Conclusion The rate of tibial plateau fracture in Japanese patients undergoing cementless UKA is high. We recommend that cemented tibial fixation should be used in Japanese patients who require very small components or have very overhanging condyles, as identified from preoperative radiographs. In the remaining 69% of knees cementless fixation can be used. This approach should result in a low rate of fracture. Cite this article: Bone Joint J 2020;102-B(7):861–867.

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“…Secondly, no available reports have shown better clinical outcomes after varus implantation than by an orthogonal cut after the OUKA. Riviere et al 11) reported on the varus tibial cut. Although it was beneficial in terms of tibial component fitting, long-term clinical outcome was not shown.…”

Section: Discussionmentioning

confidence: 99%

A Novel Technique for Varus Tibial Cutting for Oxford Unicompartmental Knee Arthroplasty

et al. 2020

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To reduce the stress on the medial tibial cortex and to decrease the risk of fracture, a varus cut of the tibia appears to be a reasonable alternative to the orthogonal cut by conventional methods. We present a new instrument and procedure, which enables a varus tibial cut for Oxford unicompartmental knee arthroplasty. We used a custom-made, slidable fixator instead of the standard fixator to set the extramedullary rod on the leg. We also made a numeric formula and a chart to arrange the varus cutting angle using the length of the mediolateral shift of the distal end and the longitudinal extension length of the extramedullary tibial rod. A varus cut up to 4.5° can be controlled. This technique is a simple and useful means of obtaining a varus tibial cut for Oxford unicompartmental knee arthroplasty.

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Kinematic alignment technique for medial OXFORD UKA: An in-silico study

Cited by 23 publications

References 25 publications

Restoration or relative overcorrection of pre-arthritic coronal alignment leads to improved results following medial unicompartmental knee arthroplasty

Restoration or relative overcorrection of pre-arthritic coronal alignment leads to improved results following medial unicompartmental knee arthroplasty

Tibial shape and size predicts the risk of tibial plateau fracture after cementless unicompartmental knee arthroplasty in Japanese patients

A Novel Technique for Varus Tibial Cutting for Oxford Unicompartmental Knee Arthroplasty

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