Biomechanical background and clinical observations of rotational malalignment in TKA:

Zihlmann, Monika Silvia; Stacoff, Alex; Roméro, J.; Quervain, Inès Kramers-de; Stüssi, Edgar

doi:10.1016/j.clinbiomech.2005.03.014

Cited by 43 publications

(39 citation statements)

References 58 publications

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“…Considerable component alignment variability, both unintentional and from differing surgical philosophy, has been quantified in the literature. Mahaluxmivala and colleagues 5 measured standard deviations of up to 48 for rotational alignment, while Zihlmann and coworkers 7 reported rotational alignment ranging from 68 internal rotation to 88 external rotation. Substantial variability also may be found with surgical choices for important variables, such as implanting the tibial component perpendicular to the mechanical axis or reproducing a natural level of posterior tibial slope.…”

Section: Discussionmentioning

confidence: 99%

“…Commonly varied surgical parameters were identified as important to the predicted position and ROM, including insert tilt 31,32 and femoral IE alignment. 7,33 Given the potential range of surgical alignments, substantial resulting performance variability may occur.…”

Section: Discussionmentioning

confidence: 99%

“…In a study of 10 cadaveric specimens, Siston and colleagues 6 measured a standard deviation of 6.58 for femoral internal-external (IE) rotational alignment when evaluating five different reference axes. In a review article, Zihlmann and coworkers 7 noted that malalignment occurred in approximately 10% to 30% of patients with observed femoral IE alignment ranging from 68 internal to 88 external rotation.…”

Section: Introductionmentioning

confidence: 99%

“…For a BW of 666 N, the peak force would vary by 240 N. This study also showed that the joint force magnitude and variability are larger during stair climbing than during gait. Variability has also been quantified in association with component placement, [5][6][7][8] as malalignment remains an underlying cause for revision surgery. In a study of 673 TKAs, Mahaluxmivala and colleagues 5 reported standard deviations of 2.38 for insert varusvalgus (VV) angle, 3.58 for insert tilt, and 3.98 for the femoral component flexion angle.…”

Section: Introductionmentioning

confidence: 99%

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Effects of knee simulator loading and alignment variability on predicted implant mechanics: A probabilistic study

et al. 2006

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Inherent variability in total knee arthroplasty loading and alignment, present in vivo and in simulator testing, may ultimately influence polyethylene tibial insert wear and long-term performance. The effect of this variability was quantified on implant kinematics and contact mechanics during simulated gait loading conditions using semi-constrained and unconstrained fixed bearing, cruciate retaining implants. A probabilistic finite element model of the Stanmore knee wear simulator was utilized to estimate the envelope of anterior-posterior (AP) and internal-external (IE) position and contact pressure and to evaluate the variability in corresponding ranges of motion (ROM). Variability levels were represented by standard deviations of up to 10% of the maximum value for load inputs and 0.25 mm and 0.58 for component alignment inputs. Model predictions compared well with experimental simulator results for the semi-constrained implant, with predicted positional envelopes of up to 1.8 mm (AP) an 3.48 (IE) for the semi-constrained and upto 2.6 mm (AP) and 3.78 (IE) for the unconstrained implant at the variability levels evaluated. ROM varied by up to 22%, while peak contact pressure variations averaged less than 2 MPa for both designs. For each implant, loading variability was more influential during the swing phase of gait, while alignment variability affected kinematics more during stance. The relative rank of sensitivities showed differences between the two designs, providing insight into critical parameters affecting kinematics and contact characteristics. ß

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Effects of knee simulator loading and alignment variability on predicted implant mechanics: A probabilistic study

et al. 2006

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“…In more recent times, the implant industry's answer to patient and surgeon dissatisfaction has been to produce gender-specific designs [5] and more anatomical femoral components. On the other side, tibiofemoral malalignment with respect to the mechanical axis and rotational malalignment have been associated with implant failure and increase in patello-femoral complication rate [6,7].…”

Section: Introductionmentioning

confidence: 99%

The effects of femoral component design on the patello-femoral joint in a PS total knee arthroplasty

Indelli

Marcucci

Pipino

et al. 2013

Arch Orthop Trauma Surg

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without need of reoperation for any reason was 98 % at 3 years minimum follow-up; two reoperations were done for removal of fibromatous intra-articular tissue ("Clunk syndrome"). There were no revisions for septic or aseptic loosening of the components. The mean rOM improved from 104° preoperatively to 115° (97°-132°) postoperatively: postoperative flexion was 120° or more in 58 % of the knees. Severe anterior knee pain was present in 9 % of patients. radiographic evaluation showed 90 knees with a tibio-femoral anatomical axis between 8° and 2° of valgus (±3° from the intraoperative goal). CT evaluation of 30 consecutive knees showed that the femoral component positioning in relationship to the trans-epicondylar axis had only 2.80° of external rotation (±2.10°) with respect to a planned external rotation of 3°. This difference was statistically significant. Conclusions Although the pFC Sigma pS system provides good and predictable results for tricompartmental arthritis of the knee, anterior mechanism complications still represent a reason for dissatisfaction in a substantial group of patients.

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Effect of component mal‐rotation on knee loading in total knee arthroplasty using multi‐body dynamics modeling under a simulated walking gait

Chen

Wang

Liu

et al. 2015

Journal Orthopaedic Research

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Mal-rotation of the components in total knee arthorplasty (TKA) is a major cause of postoperative complications, with an increased propensity for implant loosening or wear leading to revision. A musculoskeletal multi-body dynamics model was used to perform a parametric study of the effects of the rotational mal-alignments in TKA on the knee loading under a simulated walking gait. The knee contact forces were found to be more sensitive to variations in the varus-valgus rotation of both the tibial and the femoral components and the internal-external rotation of the femoral component in TKA. The varus-valgus mal-rotation of the tibial or femoral component and the internal-external mal-rotation of the femoral component with a 5˚variation were found to affect the peak medial contact force by 17.8-53.1%, the peak lateral contact force by 35.0-88.4% and the peak total contact force by 5.2-18.7%. Our findings support the clinical observations that a greater than 3˚internal mal-rotation of the femoral component may lead to unsatisfactory pain levels and a greater than 3˚varus mal-rotation of the tibial component may lead to medial bone collapse. These findings determined the quantitative effects of the mal-rotation of the components in TKA on the contact load. The effect of such malrotation of the components of TKA on the kinematics would be further addressed in future studies. Keywords: total knee arthroplasty; mal-rotation; multi-body dynamics; musculoskeletal model; contact forceThe fundamental objectives of total knee arthroplasty (TKA) are to restore normal knee joint function and to relieve pain. However, the failure in TKA resulting from clinical error and mal-alignment of the components limits the long-term survivorship of such prostheses. Dalury et al. 1 retrospectively identified 820 consecutive revision TKAs and found that malposition/mal-alignment was the seventh highest reason for revision. However, mal-position/mal-alignment also affects joint loading, component loosening and wear so that it may have a much larger effect on revision. For example, mal-rotation of the components in TKA may result in overload in the medial or lateral condyle, bone damage and bone cement crack initiation, severe wear of the polyethylene component, component loosening, and ultimately revision surgery. 2,3 In contrast, good alignment measured against the neutral position (referenced to the mechanical axis to within 2˚) after TKA leads to faster rehabilitation and better function. 4 In previous clinical studies, 5 the issue of malrotation was the most frequently discussed complication in TKA. Mal-rotation of a measurable degree has been found in approximately 10-30% of patients with TKA, depending on the surgical technique and the anatomical landmarks used. 5 Even in the hands of experienced surgeons, overall coronal mal-alignment (> AE 3˚from neutral) existed in approximately 28% of the patients. 6 Despite the improvements in surgical instruments and techniques as well as implant designs, a large percentage of the cause...

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Biomechanical background and clinical observations of rotational malalignment in TKA:

Cited by 43 publications

References 58 publications

Effects of knee simulator loading and alignment variability on predicted implant mechanics: A probabilistic study

Effects of knee simulator loading and alignment variability on predicted implant mechanics: A probabilistic study

The effects of femoral component design on the patello-femoral joint in a PS total knee arthroplasty

Effect of component mal‐rotation on knee loading in total knee arthroplasty using multi‐body dynamics modeling under a simulated walking gait

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