Medially‐stabilized total knee arthroplasty does not alter knee laxity and balance in cadaveric knees

Hall, Rachel K.; Ewing, Joseph A.; Beal, Matthew D.; Manning, David W.; Siston, Robert A.

doi:10.1002/jor.24181

Cited by 3 publications

(2 citation statements)

References 36 publications

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“…Our in vivo results approximate the in vivo knee laxities in extension and 70° flexion found in a previous study by Heesterbeek et al [9] and by other authors [1, 7–9, 11–13, 17, 18, 20–22, 26, 27] (Table 1). Exact comparison of the results with findings from previous studies is complicated by heterogeneity in the methods used to stress the knee, the amount of load applied, the unit of measurement (e.g.…”

Section: Discussionsupporting

confidence: 90%

Mid-flexion laxity in the asymptomatic native knee is predominantly present on the lateral side

Molder

Wymenga

Heesterbeek

2019

Knee Surg Sports Traumatol Arthrosc

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Purpose During total knee arthroplasty (TKA), an orthopaedic surgeon is focused on soft-tissue balance in extension (0°) and in lexion (90°). Patients with instability problems of the knee often report a feeling of instability during daily life activities, at around 30° knee lexion. There are no reference values available for knee laxity of healthy subjects in mid-lexion (30°) and lexion (90°) for comparison with the TKA population. Therefore, the aim was to quantify varus and valgus knee laxity in extension, mid-lexion and lexion in the asymptomatic native knee. Methods In 40 healthy volunteers matched for age, gender and BMI with the TKA-population, varus and valgus knee laxity in extension (0°), mid-lexion (30°) and lexion (90°) was measured on low-dose radiographs. For each subject, one randomly selected knee was stressed in extension, mid-lexion and lexion (with 15 Nm) using a stress device. Results Varus laxity in mid-lexion was higher than in extension and lexion (p < 0.01). Valgus laxity tended to be highest in mid-lexion laxity; however, no diferences in knee laxity between lexion angles were seen (n.s.). Varus knee laxity in extension was higher in females than in males (p < 0.05). Conclusions Mid-lexion laxity in the native knee is more prominent on the lateral side of the knee, while the medial side is more stable and constrained. Varus knee laxity in extension was shown to be higher in females than in males. Level of evidence Prognostic Level II.

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Section: Discussionsupporting

confidence: 90%

Mid-flexion laxity in the asymptomatic native knee is predominantly present on the lateral side

Molder

Wymenga

Heesterbeek

2019

Knee Surg Sports Traumatol Arthrosc

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“…While applied moments of different values have previously been used to assess knee laxity [34][35][36][37], we analyzed laxity data at 2 different levels: 1) a 7.5 N•m varus/valgus moment [37,38] (±7.5N•m laxity) and 2) the maximum varus/valgus moment applied to the limb (max varus/valgus laxity). We also investigated laxity in only one direction under both the 7.5 N•m and maximum applied loads (e.g., varus 7.5 N•m laxity) For the two knees that did not experience at least one trial of a ±7.5 N•m moment, only their maximum moment was calculated.…”

Section: Methodsmentioning

confidence: 99%

Intra-operative Laxity Following Total Knee Arthroplasty is Highly Variable and Different Than Osteoarthritic and Normal Knees

Siston

Hutter

Ewing

et al. 2020

Preprint

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Background: Achieving a stable joint is an important yet challenging part of total knee arthroplasty (TKA). Neither manual manipulation of the knee nor instrumented sensors biomechanically characterize knee laxity or objectively characterize how TKA changes the laxity of an osteoarthritic (OA) knee. Therefore, the purposes of this study were: 1) objectively characterize changes in knee laxity due to TKA, 2) objectively determine whether TKA resulted in equal amounts of varus-valgus motion under a given load (i.e., balance) and 3) determine how TKA knee laxity and balance differ from values seen in non-osteoarthritic knees. Methods:Two surgeons used a custom navigation system and intra-operative device to record varus-valgus motion under quantified loads in a cohort of 31 patients (34 knees ) undergoing primary TKA. Similar data previously were collected from a cohort of 42 native cadaveric knees. Results: Performing a TKA resulted in a "looser knee" on average, but great variability existed within and between surgeons. Under the maximum applied moment, 20 knees were "looser" in the varus-valgus direction, while 14 were "tighter". Surgeon 1 generally "loosened" knees (OA laxity 6.1°±2.3°, TKA laxity 10.1°±3.6°), while Surgeon 2 did not substantially alter knee laxity (OA laxity 8.2°±2.4°, TKA laxity 7.5°±3.3°). TKA resulted in balanced knees, and, while several differences in laxity were observed between OA, TKA, and cadaveric knees, balance was only different under the maximum load between OA and cadaveric knees. Conclusions: Large variability exists within and between surgeons suggests in what is considered acceptable laxity and balance of the TKA knee when it is assessed by only manual manipulation of the leg. Knees were "balanced" yet displayed different amounts of motion under applied load. Clinical Relevance: Our results suggest that current assessments of knee laxity may leave different patients with biomechanically different knees. Objective intra-operative measurements should inform surgical technique to ensure consistency across different patients.

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Better flexion and early recovery with medial-stabilized vs single-radius total knee arthroplasty with kinematic alignment: Two-year clinical results

2023

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Medially‐stabilized total knee arthroplasty does not alter knee laxity and balance in cadaveric knees

Cited by 3 publications

References 36 publications

Mid-flexion laxity in the asymptomatic native knee is predominantly present on the lateral side

Mid-flexion laxity in the asymptomatic native knee is predominantly present on the lateral side

Intra-operative Laxity Following Total Knee Arthroplasty is Highly Variable and Different Than Osteoarthritic and Normal Knees

Better flexion and early recovery with medial-stabilized vs single-radius total knee arthroplasty with kinematic alignment: Two-year clinical results

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