scholarly journals What is the “safe zone” for transition of coronal alignment from systematic to a more personalised one in total knee arthroplasty? A systematic review

Author(s):  
Benjamin L. Schelker ◽  
Andrej M. Nowakowski ◽  
Michael T. Hirschmann

Abstract Purpose In total knee arthroplasty (TKA), implants are increasingly aligned based on emerging patient-specific alignment strategies, such as unrestricted kinematic alignment (KA), according to their constitutional limb alignment (phenotype alignment), which results in a large proportion of patients having a hip-knee angle (HKA) outside the safe range of ± 3° to 180° traditionally considered in the mechanical alignment strategy. The aim of this systematic review is to investigate whether alignment outside the safe zone of ± 3° is associated with a higher revision rate and worse clinical outcome than alignment within this range. Methods A systematic literature search was conducted in PubMed, Embase, Cochrane and World of Science, with search terms including synonyms and plurals for “total knee arthroplasty”, “alignment”, “outlier”, “malalignment”, “implant survival” and “outcome”. Five studies were identified with a total number of 927 patients and 952 implants. The Oxford Knee Score (OKS) and the WOMAC were used to evaluate the clinical outcome. The follow-up period was between 6 months and 10 years. Results According to HKA 533 knees were aligned within ± 3°, 47 (8.8%) were varus outliers and 121 (22.7%) were valgus outliers. No significant differences in clinical outcomes were found between implants positioned within ± 3° and varus and valgus outliers. Likewise, no significant differences were found regarding revision rates and implant survival. Conclusion The universal use of the “safe zone” of ± 3° derived from the mechanical alignment strategy is hardly applicable to modern personalised alignment strategies in the light of current literature. However, given the conflicting evidence in the literature on the risks of higher revision rates and poorer clinical outcomes especially with greater tibial component deviation, the lack of data on the outcomes of more extreme alignments, and regarding the use of implants for KA TKA that are actually designed for mechanical alignment, there is an urgent need for research to define eventual evidence-based thresholds for new patient-specific alignment strategies, not only for HKA but also for FMA and TMA, also taking into account the preoperative phenotype and implant design. It is of utmost clinical relevance for the application of modern alignment strategies to know which native phenotypes may be reproduced with a TKA. Level of evidence IV.

Author(s):  
Benjamin Yao ◽  
Linsen T. Samuel ◽  
Alexander J. Acuña ◽  
Mhamad Faour ◽  
Alexander Roth ◽  
...  

AbstractConsiderations of how to improve postoperative outcomes for total knee arthroplasty (TKA) have included preservation of the infrapatellar fat pad (IPFP). Although the IPFP is commonly resected during TKA procedures, there is controversy regarding whether resection or preservation should be implemented, and how this influences outcomes. Therefore, the purpose of this systematic review was to evaluate how IPFP resection and preservation impacts postoperative flexion, pain, Insall-Salvati Ratio (ISR), Knee Society Score (KSS), patellar tendon length (PTL), and satisfaction in primary TKA. PubMed, EBSCO host, and SCOPUS were queried to retrieve all reports evaluating IPFP resection or preservation during TKA, which resulted into 488 studies. Two reviewers independently reviewed these articles for eligibility based on pre-established inclusion and exclusion criteria. Eleven studies were identified for final analysis, which reported on 11,996 cases. Patient demographics, type of surgical intervention, follow-up duration, and clinical outcome measures were collected and analyzed. Complete resection was implemented in 3,723 cases (31%), partial resection in 5,458 cases (45.5%), and preservation of the IPFP in 2,815 cases (23.5%). Clinical outcome measures included PTL (5 studies), knee flexion (4 studies), pain (6 studies), KSS (3 studies), ISR (3 studies), and patient satisfaction (1 study). No differences were found following IPFP resection for patient satisfaction (p = 0.98), ISR (p > 0.05), and KSS (p > 0.05). There was mixed evidence for PTL, pain, and knee flexion following IPFP resection versus preservation. Studies of shorter follow-up intervals suggested improved pain following resection, while reports of longer follow-up times indicated that resection resulted in increased pain. Given the mixed data available from the current literature, we were unable to conclude that one surgical technique can definitively be considered superior over the other. More extensive research, including randomized controlled trials, is required to better elucidate potential differences between the surgical handling choices. Future studies should focus on patient conditions in which one technique would be best indicated to establish guidelines for best surgical outcomes in those patients.


The Surgeon ◽  
2017 ◽  
Vol 15 (6) ◽  
pp. 336-348 ◽  
Author(s):  
Xiang-Dong Wu ◽  
Bing-Yan Xiang ◽  
Martijn G.M. Schotanus ◽  
Zun-Han Liu ◽  
Yu Chen ◽  
...  

2020 ◽  
pp. 1-8
Author(s):  
Stephen T. Duncan ◽  
Stephen T. Duncan ◽  
Cale Jacobs ◽  
Lucian Warth ◽  
Syed K. Mehdi

Background: There have been significant advancements to restore knee alignment postoperatively in the TKA population. This includes the use of accelerometer-based portable navigation (ABN). ABN can lead to a more precise restoration of the neutral mechanical axis, improve efficiency and potentially decrease early- and long-term complications. The degree with which ABN can achieve this remains unclear. We performed a systematic review to answer this question. Methods: We performed a systematic review in accordance with Cochrane guidelines of controlled studies (prospective and retrospective) in MEDLINE with an emphasis on studies comparing postoperative outcomes such as mechanical axis alignment, operative time, blood loss, complications and clinical outcome scores in total knee arthroplasty patients using ABN versus conventional intramedullary guides. Results: ABN was associated with significantly fewer outliers in hip-knee-ankle alignment (p = 0.0006), femoral component alignment (p < 0.0001). ABN was associated with significantly less estimated blood loss (p = 0.05) and no difference in operative times (p = 0.21). Finally, there was no difference regarding functional outcomes or DVT. Conclusion: ABN more accurately achieves neutral mechanical alignment with a smaller incidence of outliers. There was not an increase in operative time with using ABN and there were reductions in blood loss as well. We conclude that ABN offers the benefit of improved mechanical alignment.


Sign in / Sign up

Export Citation Format

Share Document