Preoperative laxity in osteoarthritis patients undergoing total knee arthroplasty

Abstract

A preoperative quantitative evaluation of soft tissues is helpful for planning total knee arthroplasty, in addition to the conventional clinical examinations involved in moving the knee manually. We evaluated preoperative coronal laxity with osteoarthritis in patients undergoing total knee arthroplasty by applying a force of 150 N with an arthrometer. We examined a consecutive series of 120 knees in 102 patients. The median laxity was 0°in abduction and 8°in adduction. The femorotibial angle on non-weight-bearing standard anteroposterior radiographs was 180°and correlated with both abduction (r=−0.244, p=0.007) and adduction (r=0.205, p=0.025) laxity. The results of a regression analysis suggested that the femorotibial angle is helpful for estimating both laxities. Considering the many reports on how to obtain well-balanced soft tissues, stress radiographs might help to improve the preoperative planning for gaining the optimal laxity deemed appropriate by surgeons.Résumé Une analyse avec évaluation quantitative préop-ératoire des tissus mous est nécessaire dans la planification d'une prothèse totale de genou, ceci en plus des examens cliniques conventionnels, notamment en ce qui concerne l'évaluation de la mobilité. Nous avons évalué, en préopératoire, les laxités ainsi que les stades de l'arthrose chez les patients qui ont bénéficié d'une prothèse totale du genou. Ces résultats ont été réalisés à l'arthromètre. Nous avons réalisé une série consécutive de 120 genoux chez 102 patients. La laxité moyenne était de 0°en abduction et de 8°en adduction. L'angle fémoro tibial, sans appui, sur les radiographies de face et de profil était de 180°et a été corrélé avec la laxité en abduction (r=−0.244, p=0.007) et en adduction (r=0.205, p= 0.025). Les résultats nous montrent que l'angle fémoro tibial est utile pour estimer les laxités. Si l'on considère les différentes études et la meilleure manière d'obtenir une bonne balance ligamentaire, les radiographies en stress permettent d'optimiser le planning opératoire et d'avoir une bonne idée des laxités.

Tibiofemoral Osteoarthritis and Varus–Valgus Laxity

“…The reference lists of the final set of articles were checked to identify additional manuscripts to include in the review, but every article of interest had already been included in the initial search. Of the 40 selected studies, 4 were prospective trials, [18][19][20][21] 16 were cohort-control designs, 11,14,[22][23][24][25][26][27][28][29][30][31][32][33][34][35] and the remaining 20 were cross-sectional studies. 13,[36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54] Laxity was a primary variable of interest in 32 of the selected studies.…”

“…Of these studies, 11 found a significant increase in some measure of laxity in the OA group compared with controls, 11,23,25-31,33,34 4 found no difference, 14,22,32,35 and 2 did not report any statistical comparisons between groups as this was not the focus of those manuscripts. 20,24 In the studies which found increased laxity, four reported increased total varus-valgus laxity, 11,23,25,31 six had increased medial, but not lateral, compartment laxity in subjects with medial knee OA, [26][27][28][29][30]34 and one found increased total varus-valgus laxity after stair climbing but not before activity. 33 Quantified varus-valgus angular laxity and joint space laxity results from these 17 studies are shown in ►Table 1 and ►Table 2, respectively.…”

Lateral Soft Tissue Laxity Increases but Medial Laxity Does Not Contract With Varus Deformity in Total Knee Arthroplasty

“…However, these measurements were performed before surgery or bone resection [1,3,9,16,20]. Therefore, surgeons try to correct intraoperative imbalance by releasing the medial soft tissues.…”

Pre-operative frontal plane malalignment predicts the extension gap asymmetry in knee osteoarthritis

“…Stress radiographs under varus and valgus conditions enable a better determination of the stability of the knee joint [12], but involve additional radiation exposure and greater costs and are therefore reserved for special questions [13]. In contrast to this, the pre-operative long standing X-ray is standard in most hospitals, as it is necessary for planning the tibial and femoral resection planes in relation to the mechanical axis [14][15][16].…”