The design and pre-clinical evaluation of knee replacements for osteoarthritis

Walker, Peter S.

doi:10.1016/j.jbiomech.2014.12.012

Cited by 10 publications

(7 citation statements)

References 46 publications

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“…For most PA techniques reported in the literature, the target for ligament balancing is described as symmetrical in extension and flexion. This assumption is classically admitted even if, in native knees, there is a higher lateral laxity in flexion than in extension or than in the medial compartment [13, 40, 52]. In extension, the knee must have an excellent stability for the walking activities, particularly during the heel‐strike phase of the gait.…”

Section: Discussionmentioning

confidence: 99%

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An anatomo-functional implant positioning technique with robotic assistance for primary TKA allows the restoration of the native knee alignment and a natural functional ligament pattern, with a faster recovery at 6 months compared to an adjusted mechanical technique

Parratte

Overschelde

Bandi

et al. 2022

Knee Surg Sports Traumatol Arthrosc

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PurposeAn anatomo‐functional implant positioning (AFIP) technique in total knee arthroplasty (TKA) could restore physiological ligament balance (symmetric gap in extension, asymmetric gap in flexion). The purposes were to compare (1) ligament balancing in extension and flexion after TKA in the AFIP group, (2) TKA alignment, implant positioning and patellar tracking between AFIP and adjusted mechanical alignment (aMA) techniques, (3) clinical outcomes between both groups at 12 months. MethodsAll robotic‐assisted TKA with an AFIP technique were included (n = 40). Exclusion criteria were genu valgum (HKA angle > 183°), extra‐articular deformity more than 10°, and patellar maltracking (high‐grade J‐sign). One control patient with a TKA implanted by an aMA technique was matched for each case, based on age, body mass index, sex, and knee alignment. Ligament balancing (medial and lateral gaps in millimeters) in full extension and at 90° of flexion after TKA in the AFIP group was assessed with the robotic system. TKA alignment (HKA angle), implants positioning (femoral and tibial coronal axis, tibial slope, joint‐line orientation), patellar tracking (patellar tilt and translation) and the Knee Society Score (KSS) at 6 and 12 months were compared between both groups. The ligament balancing was compared using a t test for paired samples in the AFIP group. The radiographic measurements and KSS scores were compared between groups using a t test for independent samples. ResultsIn the AFIP group, there was no significant difference between the medial and lateral gap laxity in extension (NS). A significant opening of the lateral gap was observed in flexion compared to extension (mean: + 2.9 mm; p < 0.0001). The mean postoperative HKA angle was comparable between both groups (177.3° ± 2.1 in the AFIP group vs 176.8° ± 3.2; NS). In the AFIP group, the femoral anatomy was restored (90.9° ± 1.6) and the tibial varus was partially corrected (87.4° ± 1.8). The improvement of Knee and Function KSS at 6 months was better in the AFIP group (59.3 ± 11.9 and 51.7 ± 20, respectively, versus 49.3 ± 9.7 and 20.8 ± 13; p < 0.001). ConclusionThe AFIP concept allowed the restoration of the native knee alignment and a natural functional ligament pattern. With a more physiological target for ligament balancing, the AFIP technique had equivalent clinical outcomes at 12 months compared to aMA, with a faster recovery. Level of evidenceIII retrospective therapeutic case control series.

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Section: Discussionmentioning

confidence: 99%

“…This ligament balancing follows the traditional assumption that a symmetrical gap in extension and flexion should be achieved. Nevertheless, in native knees, the lateral laxity is significantly greater than the medial laxity in flexion [13, 47, 52].…”

Section: Introductionmentioning

confidence: 99%

An anatomo-functional implant positioning technique with robotic assistance for primary TKA allows the restoration of the native knee alignment and a natural functional ligament pattern, with a faster recovery at 6 months compared to an adjusted mechanical technique

Parratte

Overschelde

Bandi

et al. 2022

Knee Surg Sports Traumatol Arthrosc

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“…Thus, knowledge of contact pressure and contact area in TKA is a reliable factor to predict the potential wear of the PE. 6 Various experimental methods have been used to study the tibiofemoral contact characteristics of a knee implant, including pressure-sensitive films, for example, Fuji films, 7,8 Tekscan sensors 9 and ultrasound techniques. As pressure-sensitive films are cheap, easy to use and provide satisfactory results, it has become a preferable method for testing knee implants.…”

Section: Introductionmentioning

confidence: 99%

Customized surface-guided knee implant: Contact analysis and experimental test

Khosravipour

Pejhan

Luo

et al. 2017

Proc Inst Mech Eng H

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Contact pressure and stresses on the articulating surface of the tibial component of a total knee replacement are directly related to the joint contact forces and the contact area. These stresses can result in wear and fatigue damage of the ultra-high-molecular-weight polyethylene. Therefore, conducting stress analysis on a newly designed surface-guided knee implant is necessary to evaluate the design with respect to the polyethylene wear. Finite element modeling is used to analyze the design's performance in level walking, stair ascending and squatting. Two different constitutive material models have been used for the tibia component to evaluate the effect of material properties on the stress distribution. The contact pressure results of the finite element analysis are compared with the results of contact pressure using pressure-sensitive film tests. In both analyses, the average contact pressure remains below the material limits of ultra-high-molecular-weight polyethylene insert. The peak von Mises stresses in 90° of flexion and 120° of flexion (squatting) are 16.28 and 29.55 MPa, respectively. All the peak stresses are less than the fatigue failure limit of ultra-high-molecular-weight polyethylene which is 32 MPa. The average contact pressure during 90° and 120° of flexion in squatting are 5.51 and 5.46 MPa according to finite element analysis and 5.67 and 8.14 MPa according to pressure-sensitive film experiment. Surface-guided knee implants are aimed to resolve the limitations in activities of daily living after total knee replacement by providing close to normal kinematics. The proposed knee implant model provides patterns of motion much closer to the natural target, especially as the knee flexes to higher degrees during squatting.

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“…Although such observation is in contrast to the current prevailing idea of STD as subject-specific, yet found in accordance with one study which explained overshadowing of similarity by dissimilarity for few subjects (Gao and Zheng, 2008). Secondly, segment-specific STD was observed exhibiting the highest deformation at the thigh followed by the pelvis and the shank (Akbarshahi et al, 2010; Walker, 2015). A similar observation was also reported in studies that measured higher kinematic error at the thigh (Sangeux et al, 2006; Stagni et al, 2005).…”

Section: Discussionmentioning

confidence: 99%

Experimental quantification of soft tissue deformation in quasi-static single leg flexion using biplanar imaging

Lahkar

Rohan

Yaacoub

et al. 2021

Preprint

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Soft tissue deformation(STD) causes the most prominent source of error in skin marker (SM) based motion analysis, commonly referred to as Soft Tissue Artifact (STA). To compensate for its effect and to accurately assess in vivo joint kinematics, quantification of STD in three-dimension (3D) is essential. In the literature, different invasive and radiological approaches have been employed to study how STA propagates in joint kinematics. However, there is limited reference data extensively reporting distribution of the artifact itself in 3D. The current study was thus aimed at quantifying STD in 10 subjects along three anatomical directions. Biplanar X-ray system was used to determine true bone and SM positions while the subjects underwent quasi-static single leg flexion. STD exhibited inter-subject similarity. A non-uniform distribution was observed at the pelvis, thigh and shank displaying maximum at the thigh (up to 18.5 mm) and minimum at the shank (up to 8 mm). STD at the pelvis and thigh displayed inter-marker similarity. STD at the pelvis was found direction independent, showing similar distribution in all the 3 directions. However, the thigh and shank exhibited higher STD in the proximal-distal direction of the bone embedded anatomical reference frame. These findings may provide more insights while interpreting motion analysis data as well to effectively strategize STA compensation methods.

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The design and pre-clinical evaluation of knee replacements for osteoarthritis

Cited by 10 publications

References 46 publications

An anatomo-functional implant positioning technique with robotic assistance for primary TKA allows the restoration of the native knee alignment and a natural functional ligament pattern, with a faster recovery at 6 months compared to an adjusted mechanical technique

An anatomo-functional implant positioning technique with robotic assistance for primary TKA allows the restoration of the native knee alignment and a natural functional ligament pattern, with a faster recovery at 6 months compared to an adjusted mechanical technique

Customized surface-guided knee implant: Contact analysis and experimental test

Experimental quantification of soft tissue deformation in quasi-static single leg flexion using biplanar imaging

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