Effect of Tibial Component Alignment and Posterior Slope on Tibial Coverage in a Chinese Population: A Three-dimensional Anthropometric Study

Shao, Lisheng; Wang, Ting; Liao, Junyi; Xu, Wei; Liu, Xi; Huang, Wei

doi:10.1055/s-0038-1676564

Cited by 4 publications

(4 citation statements)

References 25 publications

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“…In this modified coordinate system, each of the 3D tibia specimens was repositioned with a standard translation and rotation procedure before the virtual osteotomy. A virtual surgery was then performed on the proximal tibia at a level 8 mm below the lateral tibial plateau with a posterior slope of 7°, which had been found to be a superior slope degree for tibial component placement based on a previous study 20 (Fig. 1).…”

Section: Methodsmentioning

confidence: 99%

Approximating the maximum tibial coverage in total knee arthroplasty does not necessarily result in implant malrotation

Shao

Wang

et al. 2020

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Traditionally, the practice of the tibial component placement in total knee arthroplasty has focused on achieving maximum coverage without malrotation. However, the concept of maximizing coverage has not been well defined or researched and yet biased results are often produced. This study aimed to evaluate the effect of a prioritizing maximum coverage positioning strategy on the rotational alignment by using a strict computer algorithm. Computed tomographic scans of 103 tibial specimens were used to reconstruct three-dimensional tibia models. A virtual surgery was performed to generate the resection plane with a posterior slope of 7° on the proximal tibia. Symmetrical and anatomical tibial components were placed and analyzed with an automated program designed for approximating the maximum coverage based on the coherent point drift algorithm. We found that the average tibial coverage achieved across all specimens and implants was 85.62 ± 3.65%, ranging from 83.64 ± 4.10% to 86.69 ± 3.07%. When placed for maximal tibial coverage, the mean degree of rotation related to the Insall line was − 0.73° ± 4.53° for all subjects, 23% of the tibial components were malrotated. The average percentage position of the baseplate anteroposterior axis over the patellar tendon was 26.95 ± 14.71% from the medial edge. These results suggest that with specific design and proper placement of the component, approximating the maximum tibial coverage in total knee arthroplasty does not necessarily result in implant malrotation. the current tibial baseplates have shown good performance on the coverage when aligned parallel to the Insall line with the anteroposterior axis positioned between the medial 1/3 and medial 1/6 of the patella tendon. Insufficient implant coverage and bone support at the osteotomy level could increase the amount of bleeding into the articular cavity of the knee in the immediate postoperative period, which may also increase osteolysis from wear by debris in the long term follow-up, finally resulting in subsidence and instability 1,2. Meanwhile, proper tibial rotation is another key factor that is crucial to the kinematic alignment and long-term survivorship of the prosthesis 3-5. Ideally, a satisfying total knee arthroplasty (TKA) ought to maximize tibial coverage without causing tibial malrotation. Several studies have evaluated both tibial coverage and rotational alignment with virtual matching by using preoperative imageological data 6-13. These studies mainly focused on the comparison between anatomic and symmetric designs which had always been a controversial issue. However, the various definitions of the malrotation and coverage maximizing methods applied in these studies make it hard to draw a firm conclusion on the compromise between coverage and ideal rotation while the latter has an inherent priority 8,14. Theoretically, maximizing coverage usually requires a larger size of the tibial baseplate, which under normal circumstances

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Section: Methodsmentioning

confidence: 99%

Approximating the maximum tibial coverage in total knee arthroplasty does not necessarily result in implant malrotation

Shao

Wang

et al. 2020

Sci Rep

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“…In a similar study by Shao et al, cuts were made at 0, 3, 5, and 7 degrees of slope at a resection level different than that in our study, and it was reported that the coverage was increased in both the symmetric and asymmetric components, when the slope angle was increased toward 7 degrees in ideal rotation. 12 However, the resection level was 8 mm below the lateral plateau in the said study. Surgical instruments that targeted 3-mm below the deepest point of the medial plateau were used in our surgical practice, which may account for the result difference between the studies.…”

Section: Discussionmentioning

confidence: 74%

“…6 Asymmetric tibial component designs have been developed; however, these twocomponent types cannot usually prevent overhang from the posteromedial or posterolateral zones during a well-aligned tibial component placement from the mediolateral and anterior aspects of the ideal component rotation. [7][8][9][10][11][12] Therefore, this study aimed to investigate (1) whether the tibial surface area exhibited any changes following tibial plateau cuts at different slope angles, (2) whether there was a change in the compatibility of the symmetric or asymmetric tibial baseplates with the tibial surface or overhang beyond bone margins following cuts at different slope angles, and (3) which slope cut angle could reduce the overhang or underhang. The hypothesis of our study was that during the implantation of the tibial component by providing rotational, mediolateral, and maximum coverage, overhang/underhang that may occur in the posterior cortex of the tibial component can be avoided by using different slope cut angles.…”

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confidence: 99%

Low-Degree Tibial Slope Angle Prevents Component Overhang by Enlarging the Lateral Plateau Surface Area in Total Knee Arthroplasty

et al. 2020

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This study aimed to investigate whether overhang or underhang around the tibial component that occurs during the placement of tibial baseplates was affected by different slope angles of the tibial plateau and determine the changes in the lateral and medial plateau diameters while changing the slope angle in total knee arthroplasty. Three-dimensional tibia models were reconstructed using the computed tomography scans of 120 tibial dry bones. Tibial plateau slope cuts were performed with 9, 7, 5, 3, and 0 degrees of slope angles 2-mm below the subchondral bone in the deepest point of the medial plateau. Total, lateral, and medial tibial plateau areas and overhang/underhang rates were measured at each cut level. Digital implantations of the asymmetric and symmetric tibial baseplates were made on the tibial plateau with each slope angles. Following the implantations, the slope angle that prevents overhang or underhang at the bone border and the slope angle that has more surface area was identified. A significant increase was noted in the total tibial surface area, lateral plateau surface area, and lateral anteroposterior distance, whereas the slope cut angles were changed from 9 to 0 degrees in both gender groups. It was found that the amount of posteromedial underhang and posterolateral overhang increased in both the asymmetric and symmetric tibial baseplates when the slope angle was changed from 0 to 9 degrees. Although the mediolateral diameter did not change after the proximal tibia cuts at different slope angles, the surface area and anteroposterior diameter of the lateral plateau could change, leading to increased lateral plateau area. Although prosthesis designs are highly compatible with the tibial surface area, it should be noted that the component overhangs, especially beyond the posterolateral edge, it can be prevented by changing the slope cut angle in males and females.

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“…30 Other risk factors such as age, BMI, ethnicity, and gender have also been proven to affect proximal tibial morphology, and as such will not necessarily be equally applicable to standardized tibial baseplates. 31,32 Local Tenderness…”

Section: Prevalence Incidence and Size Of Overhangmentioning

confidence: 99%

An Investigation of Medial Tibial Component Overhang in Unicompartmental and Total Knee Replacements Using Ultrasound in the Outpatient Department

et al. 2021

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Tibial component overhang is known to be a contributor to worse outcomes in knee arthroplasty. The aim of this study is to investigate the presence of tibial component overhang, and whether overhang correlates to a higher local tenderness in both medial unicompartmental and total knee replacements. Also, to determine if a rotational projection phenomenon is presented with radiographs when investigating tibial component overhang. A prospective study, including 64 participants, was performed, where ultrasound measurements were compared with postoperative radiographs. Local tenderness was measured as a pressure pain threshold, determined at 3 months postoperatively using algometry. Sixty-two of sixty-four patients had an underdiagnosed medial overhang on radiographs, with a mean difference of 2.4 mm between radiographs and ultrasound (p < 0.001), presenting a rotational projection phenomenon. When comparing sites with ultrasound measured overhang to sites without overhang measured by ultrasound, a higher local tenderness was observed (p < 0.001). A positive linear correlation was found between patients' overhang and local tenderness (r = 0.2; p = 0.045). Subgroup analysis of medial overhang showed significantly higher tenderness than all other locations. No significant differences were seen for lateral overhang. An apparent rotational projection phenomenon of overhang on radiographs was seen, and a linear association between overhang and local tenderness was demonstrated. This study warrants the use of ultrasound when a surgeon is presented with a patient with postoperative medial tenderness, but no overhang can be seen on radiographs. It should also raise awareness of implant selection and positioning during surgery, especially avoiding the overhang to be localized directly medially.

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Effect of Tibial Component Alignment and Posterior Slope on Tibial Coverage in a Chinese Population: A Three-dimensional Anthropometric Study

Cited by 4 publications

References 25 publications

Approximating the maximum tibial coverage in total knee arthroplasty does not necessarily result in implant malrotation

Approximating the maximum tibial coverage in total knee arthroplasty does not necessarily result in implant malrotation

Low-Degree Tibial Slope Angle Prevents Component Overhang by Enlarging the Lateral Plateau Surface Area in Total Knee Arthroplasty

An Investigation of Medial Tibial Component Overhang in Unicompartmental and Total Knee Replacements Using Ultrasound in the Outpatient Department

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