No difference in patient-reported satisfaction after 12 months between customised individually made and off-the-shelf total knee arthroplasty

Knee Surgery, Sports Traumatology, Arthroscopy https://doi.org/10.1007/s00167-022-06900-z KNEE No difference in patient‑reported satisfaction after 12 months between customised individually made and off‑the‑shelf total knee arthroplasty Séverin Wendelspiess1,2 · Raphael Kaelin1 · Nicole Vogel1,2 · Thomas Rychen1 · Markus P. Arnold1,2 Received: 12 October 2021 / Accepted: 16 January 2022 © The Author(s) 2022 Abstract Purpose A subset of patients is usually not satisfied after a total knee arthroplasty (TKA). Customised individually made (CIM) TKA are deemed to overcome drawbacks of classical off-the-shelf (OTS) TKA, but evidence is still sparse. The aim of this study was to compare satisfaction of patients with CIM and OTS TKA. Methods This prospective cohort study compared clinical and patient-reported outcome measures (PROM) between patients with CIM and OTS TKA. The primary outcome was patient satisfaction after 12 months. Secondary outcomes were the Knee Society Score (KSS), the Knee injury and Osteoarthritis Outcome Score (KOOS), the Forgotten Joint Score (FJS-12) and the EQ-5D-3L after 4 and 12 months. Results Data were analysed from 74 CIM TKA and 169 OTS TKA between January 2017 and September 2020. Patients with CIM TKA were slightly younger, more often male, had a lower body mass index, a lower KSS and partially higher preoperative PROMs. Patient satisfaction after 12 months was high and comparable (CIM 87%, OTS 89%). All PROMs improved for both groups (p < 0.001) and did not differ after 12 months (p > 0.063). The majority of patients improved above the minimal important difference (range 65 to 89%) and reported a clear overall improvement (CIM 86%, OTS 87%). The postoperative KSS, notably regarding knee stability, was higher for CIM TKA (p < 0.001). Conclusion No difference was found in patient satisfaction between CIM and OTS TKA after 12 months. In both groups, patient satisfaction was high and PROMs improved considerably. Level of evidence II, prospective cohort study. Keywords Arthroplasty · Replacement · Knee · Custom · Patient-specific · Patient-reported outcome measure · Patient satisfaction Abbreviations ASA American Society of Anesthesiologists CIM Customised individually made FDA US Food and Drug Administration Séverin Wendelspiess and Raphael Kaelin shared the first authorship and contributed equally. * Nicole Vogel 1 Practice LEONARDO, Hirslanden Clinic Birshof, Reinacherstrasse 28, 4142 Münchenstein, Switzerland 2 Faculty of Medicine, University of Basel, Basel, Switzerland FJS-12 Forgotten Joint Score KOOS Knee injury and Osteoarthritis Outcome Score KSS Knee Society Score MID Minimal important difference OTS Off-the-shelf PROM Patient-reported outcome measure SD Standard deviation 13 Vol.:(0123456789) Knee Surgery, Sports Traumatology, Arthroscopy TKA Total knee arthroplasty VAS Visual analogue scale Introduction About 20% of patients are not satisfied after a total knee arthroplasty (TKA) [6, 12, 15]. A variety of predictors for dissatisfaction have been identified: female sex, lower grade of osteoarthritis, implant-related reasons, mental health problems, unfulfilled expectations, postoperative pain and limited function are only some of these [12, 15, 21, 29]. Moreover, the number of TKA is rising among younger and more active patients with high functional expectations [31]. Although TKA is a common, safe and cost-effective treatment for end-stage knee osteoarthritis [3, 12], the procedure does not entirely restore normal biomechanics and functional limitations may occur [26]. Classical off-the-shelf (OTS) TKA can cause implant overhang, malalignment and abnormal kinematics [20, 41]. One reason may be the high variability of knee phenotypes between individuals, ethnicities and sex [4, 7, 13, 19, 22]. Customised individually made (CIM) TKA have been developed to overcome these problems and improve outcome after TKA [5, 17, 44]. CIM TKA incorporate a bone-preserving approach using custom planning images, implants and instrumentation [44]. The personalised approach respects the patient’s individual knee anatomy and eliminates implant sizing compromises [18, 45]. Disadvantages of CIM TKA are a prolonged waiting time for the manufacturing, a higher radiation exposure [44] and limited intraoperative implant options [45]. To get a better understanding of the patients’ perspective, their satisfaction after TKA and potential problems in daily life, an evaluation of patient-reported outcome measures (PROM) is necessary. CIM TKA are relatively new, available in the US and Europe since 2011 [9] and at our hospital since 2015. First results are promising in terms of bone preservation [45], ligament balancing [45], alignment [2, 54] and patient satisfaction [32, 37]. However, sufficient data are still lacking: comparative studies are sparse and randomised controlled trials on this topic are absent [25, 51]. A prospective study comparing PROMs of patients with CIM and OTS TKA has not yet been published. The aim of this study was to analyse patient-reported satisfaction; further PROMs and clinical outcome of patients with CIM TKA were compared to OTS TKA. Our hypothesis was that CIM TKA are superior to OTS TKA. 13 Materials and methods Study design, setting and recruitment This is a single-side, observational, prospective cohort study. The study is in accordance with the World Medical Association Declaration of Helsinki [48]. All patients were recruited in our medical practice, based in a private hospital, and gave their written informed consent. Since 2017, all patients scheduled for any type of knee arthroplasty were asked to complete a set of PROMs. Patients with insufficient knowledge of German, English, French or Italian were excluded. Details regarding recruitment and procedures are published in the study protocol [52]. The current study included consecutive patients with a primary cruciate-retaining CIM TKA (iTotal CR G2, ConforMIS Inc., Bedford, MA, US) or cruciateretaining OTS TKA (Attune® CR mobile-bearing, DePuy Synthes, Raynham, MA, US) who completed PROMs before the surgery and after 12 months. Patients with revision surgery or major re-operation on the affected knee were excluded. All TKA were performed between January 2017 and September 2020 by MPA (CIM and OTS) and by RK and TR (OTS), all of them well-experienced senior surgeons. CIM TKA patients chose their surgeon (MPA) accordingly because of their interest in the new technology. In rare cases, the patient was made aware of the possibility of a CIM TKA because of a marked joint line obliquity (tibial mechanical angle of ≤ 84° on long-leg radiographs) with an obvious anatomical difference in shape between the medial and lateral femoral condyles or hypoplasia of the lateral femoral condyle [13]. Surgical technique All patients had the same peri- and postoperative anaesthesia and pain management protocol. Preoperative, all patients received 1 g of tranexamic ac (...truncated)