A double-blind randomized controlled trial of total knee replacement using patient-specific cutting block instrumentation versus standard instrumentation

Abstract

Background: Patient-specific cutting blocks in total knee arthroplasty have been promoted to improve mechanical alignment, reduce alignment outliers and improve patient outcomes. The aim of this study was to compare the efficacy of patientspecific instrumentation (PSI) and conventional instrumentation (CI) in achieving neutral alignment and accurate component positioning in total knee arthroplasty. Methods: We conducted a double-blinded randomized controlled trial in which patients were randomly assigned to treatment with either PSI or CI. Results: Fifty-four patients were included in the study. No relevant improvement in coronal alignment was found between the PSI and CI groups with post-hoc power of 0.91. Tibial slope was found to be more accurately reproduced to the preoperative target of 3° with PSI than with CI (3.8°± 3.1° v. 7.7°± 3.6°, respectively, p < 0.001). There were no differences found in patient-reported outcome measures, surgical time or length of hospital stay. Conclusion: Given the added cost of the PSI technique, its use is difficult to justify given the small improvement in only a single alignment parameter. Clinical trial registration: Clinicaltrials.gov, no. NCT03416946. Contexte : L'utilisation de guides de coupe sur mesure dans l'arthroplastie totale du genou a été recommandée pour améliorer l'alignement mécanique, réduire les alignements extrêmes et améliorer les résultats des patients. Cette étude cherchait à comparer la capacité des instruments sur mesure et des instruments classiques à engendrer un alignement neutre et un bon positionnement des composants dans le cadre d'une arthroplastie totale du genou. Méthodes : Nous avons mené un essai clinique randomisé à double insu. Les patients étaient répartis aléatoirement entre le groupe de traitement avec instruments sur mesure et le groupe de traitement avec instruments classiques. Résultats : Cinquante-quatre patients ont participé à l'étude. Aucune différence notable de l'alignement coronal entre les groupes n'a été relevée, pour une puissance observée de 0,91. La pente tibiale correspondait plus exactement à la cible préopératoire de 3° avec les instruments sur mesure qu'avec les instruments classiques (3,8° ± 3,1° contre 7,7° ± 3,6°, respectivement; p < 0,001). Il n'y avait aucune différence dans les mesures déclarées par les patients, la durée de l'intervention et la durée d'hospitalisation. Conclusion : Étant donné l'amélioration minime d'un seul paramètre d'alignement et le coût supérieur de la technique sur mesure, son utilisation est difficile à justifier. Enregistrement de l'essai : Clinicaltrials.gov, no NCT03416946.

Accurate implant fit and leg alignment after cruciate-retaining patient-specific total knee arthroplasty

“…Other authors have reported, up to 8,5% of cuts being suboptimal using conventional techniques [ 22 ]. Several other studies have demonstrated that factors such as the optimal surgical techniques [ 22 , 23 ], the use of computer navigation [ 24 ], or patient-specific instruments [ 25 , 26 ] are able to improve the outcome of patients. Especially the use of computer navigation and the use of PSI are thought to overcome the above mentioned accuracy limitations at the cost of the investment and more surgical time in case of computer navigation.…”

Benefits of Tranexamic Acid in Total Knee Arthroplasty: A Classification and Regression Tree Analysis in Function of Instrumentation, BMI, and Gender

“…[30][31][32]34 Since it is an inhibitor of TPA, and since both TXA and PAI-1 are important inhibitors of fibrinolysis, their synergism can result in a greater antifibrinolytic effect. 30 The main surgical difference between CI and PSI is that the former implies marrow perforation, 3,5,8,10 which alone could possibly explain the superior results of CI when combined with the use of TXA in terms of blood loss. Not only the highly invasive surgery has been shown to promote a hypercoagulable state, 21 which results in lower blood loss, but also there is PAI-1 production at the site of tissue injury resulting from inflammation associated with the surgical incision.…”

“…[1][2][3][4][5][6][7][8][9][10][11] Conventional instrumentation (CI), the standard option for TKA, uses intramedullary and/or extramedullary alignment systems that rely too much on visual references which can lead even an experienced surgeon to produce undesired postoperative axes. 5,8,10 These devices not only complicate the workflow and prolong surgery time but also can increase blood loss and the risk of fat embolism, as they are more invasive. 5,10 Patient-specific instrumentation (PSI) emerged in the last two decades as an alternative to CI, aiming to improve accuracy and cost effectiveness in daily use, as well as reduce operating times, and blood loss caused by TKA.…”

“…5,10 Patient-specific instrumentation (PSI) emerged in the last two decades as an alternative to CI, aiming to improve accuracy and cost effectiveness in daily use, as well as reduce operating times, and blood loss caused by TKA. 1,3,5,8,12,13 TKA frequently presents perioperative blood losses, due to soft-tissue dissection and bone cuts, [14][15][16][17][18] estimated between 1,500 and 2,000 mL, with a predictable decrease of 3 g/dL of hemoglobin (Hb) for every 1,000 mL of blood loss. 12,19 Blood loss increases morbidity, mortality and dissatisfaction of patients but it also prolongs hospital admission and increases costs.…”

Computed Tomography-Based Patient-Specific Instrumentation Loses Accuracy with Significant Varus Preoperative Misalignment

“…1 During the past decade, patientspecific instrumentation (PSI) has been commercially introduced to simplify and make TKA surgery more precise, effective, and efficient. Several studies, systematic reviews, and meta-analysis [2][3][4][5][6][7][8][9][10][11][12][13][14][15] have been published examining the efficacy of PSI in accurately reproducing a neutral mechanical axis in coronal alignment. Most contemporary publications do not claim a significant increase in PSI accuracy over conventional mechanical instrumentation (CI), but they also do not postulate PSIs accuracy is worse.…”