Midterm outcomes of electromagnetic computer-assisted navigation in minimally invasive total knee arthroplasty

American Academy of Orthopaedic Surgeons Clinical Practice Guideline Summary of Surgical Management of Osteoarthritis of the Knee

The Surgical Management of Osteoarthritis of the Knee Evidence-Based Clinical Practice Guideline is based on a systematic review of published studies for surgical management of osteoarthritis of the knee in skeletally mature patients. This guideline contains 16 recommendations and seven options to assist orthopaedic surgeons and all qualified physicians with the surgical management of patients with osteoarthritis of the knee based on the best current available evidence. It is also intended to serve as an information resource for professional healthcare practitioners and developers of practice guidelines and recommendations. In addition to providing pragmatic practice recommendations, this guideline also highlights gaps in the literature and informs areas for future research and quality measure development.

Electromagnetic Navigated Versus Conventional Total Knee Arthroplasty-A Five-Year Follow-Up of a Single-Blind Randomized Control Trial

BACKGROUND

The objective of this study is to provide the 5-year follow-up results of a randomized study comparing conventional versus electromagnetic computer navigated total knee arthroplasty.

METHODS

Analysis of 127 patients (66 navigated and 61 conventional surgeries) was performed from a prospective, single-blinded, randomized controlled trial. Patient-reported outcome measures were collected at 5 years after surgery and compared with previously published 1-year clinical outcomes. Five-year surgical revision rates were collated and compared between intervention groups.

RESULTS

Overall, there have been continued improvements in the clinical scores of patients in both groups when compared with clinical data at 1 year; however, at 5 years, there is no statistical difference in any of the patient-reported outcome measures between conventional and navigated surgery. Interestingly, improved implant survivorship was observed in the navigated (0% revision rate) compared with the conventional group (4.9% all-cause revision rate).

CONCLUSION

Electromagnetic computer navigated technology produces similar clinical outcomes compared with traditional surgery. Further work is required to monitor implant survivorship, and clinical outcomes with long-term follow-up, to determine the cost effectiveness of this technology.

Computer-Navigated versus Conventional Total Knee Arthroplasty: A Meta-Analysis of Functional Outcomes from Level I and II Randomized Controlled Trials

The main purpose of this article is to provide an up-to-date systematic review and meta-analysis comparing functional outcomes of total knee arthroplasty using either computer navigation (NAV-TKA) or conventional methods (CON-TKA) from the latest assemblage of evidence. This study was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Meta-Analysis of Observational Studies in Epidemiology guidelines. All Level I and II randomized controlled trials (RCTs) in PubMed, EMBASE, and Cochrane that compared functional outcomes after NAV- and CON-TKA were included in the review. Selected end points for random effects, pairwise meta-analysis included Knee Society Knee Score (KSKS), KS Function Score (KSFS), KS Total Score (KSTS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and range of motion at three arbitrary follow-up times. A total of 24 prospective RCTs comprising 3,778 knees were included from the initial search. At long-term follow-up (>5 years), NAV-TKA exhibited significantly better raw KSKS (p = 0.001) (low-quality evidence), contrary to CON-TKA, which reflected significantly better raw KSTS (p = 0.004) (high-quality evidence). While change scores (KSKS, WOMAC) from preoperative values favor CON-TKA at short-term (<6 months) and medium-term follow-up (6-60 months), long-term follow-up change scores in KSKS suggest the superiority of NAV-TKA over CON-TKA (p = 0.02) (very low-quality evidence). Overall, sizeable dispersion of nonstatistically significant functional outcomes in the medium term was observed to eventually converge in the long term, with less differences in functional outcome scores between the two treatment methods in short- and long-term follow-up. While raw functional outcome scores reflect no differences between NAV and CON-TKA, long-term follow-up change scores in KSKS suggest superiority of NAV-TKA over its conventional counterpart. Prospective studies with larger power are required to support the pattern of diminishing differences in functional outcome scores from medium- to long-term follow-up between the two modalities.

Patellar Denervation Reduces Postoperative Anterior Knee Pain After Patellar Resurfacing Total Knee Arthroplasty: A Randomized Controlled Trial

BACKGROUND

The benefit of patellar denervation (PD) in patellar resurfacing total knee arthroplasty (TKA) is still debatable. This prospective, randomized controlled trial investigated whether circumferential PD should be performed in patellar resurfacing TKA.

METHODS

A total of 241 patients who underwent unilateral TKA were randomized into PD or non-PD groups. Incidence, intensity, and presentation time of anterior knee pain (AKP) and clinical outcomes were evaluated at 3, 6, 9, 12, 18, and 24 months postoperatively.

RESULTS

The incidence of AKP was significantly lower in the PD group (6.4% vs 16.2%, P = .032). The intensity of AKP and patient satisfaction scores were significantly better in the PD group at 3 months but not after 3 months. The presentation time of AKP mostly occurs at 3 months after surgery. The Knee Society score, range of motion, Oxford score, patellar score, activity of daily living score, and visual analog scale of overall knee pain were not significantly different between the two groups during the follow-up period.

CONCLUSION

Given that PD can improve AKP and patient satisfaction at an early period postoperatively without jeopardizing clinical outcomes at no additional cost, this inexpensive procedure readily available in nearly every operation room is strongly recommended during primary TKA with patellar resurfacing.

Computer and robotic - assisted total knee arthroplasty: a review of outcomes

Background

Total knee arthroplasty (TKA) is a successful treatment for tricompartmental knee arthritis. Computer navigation and robotic-assisted-surgery (RAS) have emerged as tools that aim to help plan and execute surgery with greater precision and consistency. We reviewed the most current literature to describe the historical background and outcomes compared to conventional TKA.

Methods

A review and synthesis of the literature comparing the patient reported outcomes (PROM’s) of RA TKA and computer-assisted (CA) TKA to conventional TKA was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

Results

CAS TKA improves accuracy and consistency of implant position, and appears to provide a small improvement in PROMs and implant survival compared to conventional TKA. RTKA similarly improves implant accuracy compared to conventional techniques and early results suggest a similar small benefit in PROMs compared to conventional TKA. A strengthening trend is emerging showing CAS TKA has greatest benefit to implant survival in people under 65. RTKA survival analysis data is more limited and early results do not allow strong conclusions, however early trends are similar to CAS TKA.

Conclusion

Results for CAS-TKA show improvement in alignment, and early clinical outcomes have revealed promising results, with longer-term data and medium-term survival analysis recently emerging showing small benefits over conventional TKA. RTKA represents another phase of development. Early results show similar trends to that of CAS TKA with longer-term data still to come.

Mini-midvastus versus medial parapatellar approach in total knee arthroplasty: difference in patient-reported outcomes measured with the Forgotten Joint Score

Background

Low knee awareness after minimally invasive total knee arthroplasty (TKA) has become the ultimate target of a natural-feeling knee that meets patient expectations. The objective of this research was to compare the clinical outcomes of TKA via the mini-midvastus (MMV) approach or the medial parapatellar (MPP) approach, and to evaluate which approach can lead to a better quality of life after surgery.

Methods

From January 2015 to December 2016, a retrospective cohort study was conducted in 330 patients who underwent TKA via a mini-midvastus (MMV) approach. During this period, we also selected 330 patients who underwent TKA via a medial parapatellar (MPP) approach (MPP group) for comparison. Clinical results were assessed with the visual analog scale score for pain, range of motion, and the Knee Society Score. The Forgotten Joint Score was used to analyze the ability to forget the joint.

Results

There were significant differences with regard to visual analog scale score, range of motion, and the Knee Society Score until 6 months after surgery between the MMV and MPP groups (p < 0.05), but the differences were not significant at 12 months, 24 months, and 36 months after surgery. However, there were significant differences in the Forgotten Joint Score between the groups during the follow-up period (p < 0.05).

Conclusion

When forgetting the artificial joint after TKA is the ultimate target, better quality of life can be acquired by performing TKA via the MMV approach. In addition, compared with the MPP approach, the MMV approach can offer less pain and a faster recovery.

Computer Navigation-Assisted Knee Replacement Demonstrates Improved Outcome Compared with Conventional Knee Replacement at Mid-Term Follow-up: A Systematic Review and Meta-analysis

The study is a systematic review and meta-analysis of prospective randomised control studies and prospective cohort studies of mid-term functional outcome of total knee replacement undertaken using imageless computer navigation compared with conventional instrumented total knee replacement. The literature search strategy included a search of the electronic databases, visual scanning of reference lists, hand searching of key journals and conference proceedings, and abstracts, citations, and trial registers. In total, 440 papers were retrieved after removal of duplicates, and with further screening, 11 papers were included in the systematic review and 6 papers were considered appropriate for meta-analysis. Analysis of the data showed evidence of a modest improvement in functional outcome at mid-term follow-up with use of imageless computer navigation assistance compared with conventional instrumented total knee replacement with a total score point estimate of 3.36 confidence interval (CI) (- 0.583, 7.298), objective score point estimate of 1.45 CI (0.11, 2.799), and functional score point estimate of 2.4, CI (- 1.174, 5.977). The predominant risk of bias was from random allocation and attrition. There is evidence of a modest improvement in functional outcome with the use of imageless computer navigation assistance compared with conventional instrumented total knee replacement at mid-term follow-up.

Conventional versus Smart Wireless Navigation in Total Knee Replacement: Similar Outcomes in a Randomized Prospective Study

Purpose  The development of new computer-assisted navigation technologies in total knee arthroplasty (TKA) has attracted great interest; however, the debate remains open as to the real reliability of these systems. We compared conventional TKA with last generation computer-navigated TKA to find out if navigation can reach better radiographic and clinical outcomes.

Methods  Twenty patients with tricompartmental knee osteoarthritis were prospectively selected for conventional TKA ( n  = 10) or last generation computer-navigated TKA ( n  = 10). Data regarding age, gender, operated side, and previous surgery were collected. All 20 patients received the same cemented posterior-stabilized TKA. The same surgical instrumentation, including alignment and cutting guides, was used for both the techniques. A single radiologist assessed mechanical alignment and tibial slope before and after surgery. A single orthopaedic surgeon performed clinical evaluation at 1 year after the surgery. Wilcoxon's test was used to compare the outcomes of the two groups. Statistical significance was set at p  < 0.05.

Results  No significant differences in mechanical axis or tibial slope was found between the two groups. The clinical outcome was equally good with both techniques. At a mean follow-up of 15.5 months (range, 13–25 months), all patients from both groups were generally satisfied with a full return to daily activities and without a significance difference between them.

Conclusion  Our data showed that clinical and radiological outcomes of TKA were not improved by the use of computer-assisted instruments, and that the elevated costs of the system are not warranted.

Level of Evidence  This is a Level II, randomized clinical trial.

Mini-subvastus versus medial parapatellar approach for total knee arthroplasty: a prospective randomized controlled study

PURPOSE

Whether minimally invasive total knee arthroplasty (MIS-TKA) could offer better and faster recovery without the deviation of post-operative prosthesis position and limb alignment is still controversial. This prospective and randomized study was conducted to compare the clinical and radiological outcomes between patients who underwent the mini-subvastus approach of MIS-TKA and those who underwent the medial parapatellar approach of traditional TKA.

METHODS

Fifty patients, including 50 knees, who required TKA due to osteoarthritis were randomized to the mini-subvastus group (group I) or the medial parapatellar group (group II). All patients accepted the same method of anaesthesia, equal support therapy and identical rehabilitation exercise after surgery. The evaluation system included operation time, tourniquet time, blood loss, skin incision length in flexion, straight leg raising time, the time of lower limb muscle strength up to grade 4, the time of walking with aid or without aid, the time of walking up and down the stairs, the active flexion angle, range of movement (ROM), the Knee Society Scores (KSS), visual analogue score for pain (VAS), hospital stays and radiographic outcomes.

RESULTS

The mini-subvastus approach offered smaller skin incision length in flexion, but at the cost of operation time (P < 0.001). No significant difference was found in tourniquet time and blood loss. The patients in group I could achieve straight leg raising, the lower limb muscle strength up to grade 4, walking with or without aid, and walking up and down the stairs earlier (P < 0.001). The active flexion angle, ROM, VAS and KSS in group I were superior to those in group II until six months post-operatively (P < 0.001), but the differences was not apparent at 12 months post-operatively. More importantly, there was no significant difference between the two groups on radiological outcomes (P > 0.05).

CONCLUSIONS

The mini-subvastus approach could offer faster recovery, less pain and shorter hospital stays without compromising the principles of proper prosthesis position and limb alignment compared with the medial parapatellar approach.

Current state of computer navigation and robotics in unicompartmental and total knee arthroplasty: a systematic review with meta-analysis

Recently, there is a growing interest in surgical variables that are intraoperatively controlled by orthopaedic surgeons, including lower leg alignment, component positioning and soft tissues balancing. Since more tight control over these factors is associated with improved outcomes of unicompartmental knee arthroplasty and total knee arthroplasty (TKA), several computer navigation and robotic-assisted systems have been developed. Although mechanical axis accuracy and component positioning have been shown to improve with computer navigation, no superiority in functional outcomes has yet been shown. This could be explained by the fact that many differences exist between the number and type of surgical variables these systems control. Most systems control lower leg alignment and component positioning, while some in addition control soft tissue balancing. Finally, robotic-assisted systems have the additional advantage of improving surgical precision. A systematic search in PubMed, Embase and Cochrane Library resulted in 40 comparative studies and three registries on computer navigation reporting outcomes of 474,197 patients, and 21 basic science and clinical studies on robotic-assisted knee arthroplasty. Twenty-eight of these comparative computer navigation studies reported Knee Society Total scores in 3504 patients. Stratifying by type of surgical variables, no significant differences were noted in outcomes between surgery with computer-navigated TKA controlling for alignment and component positioning versus conventional TKA (p = 0.63). However, significantly better outcomes were noted following computer-navigated TKA that also controlled for soft tissue balancing versus conventional TKA (mean difference 4.84, 95 % Confidence Interval 1.61, 8.07, p = 0.003). A literature review of robotic systems showed that these systems can, similarly to computer navigation, reliably improve lower leg alignment, component positioning and soft tissues balancing. Furthermore, two studies comparing robotic-assisted with computer-navigated surgery reported superiority of robotic-assisted surgery in controlling these factors. Manually controlling all these surgical variables can be difficult for the orthopaedic surgeon. Findings in this study suggest that computer navigation or robotic assistance may help managing these multiple variables and could improve outcomes. Future studies assessing the role of soft tissue balancing in knee arthroplasty and long-term follow-up studies assessing the role of computer-navigated and robotic-assisted knee arthroplasty are needed.

Minimally Invasive Computer-Assisted Total Knee Arthroplasty Compared With Conventional Total Knee Arthroplasty: A Prospective 9-Year Follow-Up

BACKGROUND

Studies on minimally invasive computer-assisted total knee arthroplasty (MICA-TKA) have shown promising results, but are limited by short follow-up. The purpose of this study was to compare the midterm radiographic features and functional outcomes between patients who underwent MICA-TKA and conventional TKA.

METHODS

A total of 108 patients who were randomized to undergo MICA-TKA or conventional TKA during 2004 and 2005 were contacted for a prospective follow-up review. Patients who were lost to contact, have passed away, or declined to participate in the study were excluded. Objective functional measurements and radiographs were obtained for assessment.

RESULTS

By the time of this study, 2 patients from the conventional group had undergone revision TKA, one due to infection and one due to aseptic loosening. A total of 67 patients (62.04%) were followed up for an average period of 9.07 years (8.51-9.61 years). At follow-up, functional scores were comparable between the 2 groups. No significant intergroup differences were found in mechanical knee alignment and component placement angle in the coronal views. No statistical or clinical significance were noticed in radiographic signs of component loosening.

CONCLUSIONS

MICA-TKA provided similar clinical, functional, and radiographic outcomes compared with conventional TKA after an average of 9-year follow-up. This technique can be used to exploit its short-term advantages without compromising midterm outcomes.

A Comparison of Short-Term Outcomes of Minimally Invasive Computer-Assisted vs Minimally Invasive Conventional Instrumentation for Primary Total Knee Arthroplasty: A Systematic Review and Meta-Analysis

BACKGROUND

Median parapatellar approach is the most used for total knee arthroplasty (TKA). With the advent of enhanced recovery and shorter length of hospital stay, there is an increasing pressure on surgeons to perform surgery through smaller incisions. Minimally invasive (MIS) TKA allows earlier functional recovery; it is not clear if this is associated with more complications. It is also unclear if computer-assisted minimally invasive (MIS CA) TKA has any affect on improving patient outcomes. We performed a systematic review and meta-analysis comparing MIS CA vs MIS TKA.

METHODS

We performed an extensive literature search including both randomized controlled studies and prospective cohort studies. All data reported on component alignment, surgical time, complications, knee flexion, and postoperative functional knee scores were included for analysis.

RESULTS

Ten studies were suitable for inclusion resulting in 490 patients with MIS CA and 503 MIS patients. There was no significant difference in the outliers on complications, knee flexion, and postoperative functional scores. Coronal plane tibial component showed statistically significant number of outliers in the MIS group demonstrating superior component positioning in the MIS CA group. Operative time was significantly longer in the MIS CA group with a mean increase of 32 minutes.

CONCLUSIONS

Computer-assisted minimally invasive TKA is superior than the standard MIS TKA in terms of component positioning; however, it is unclear if this will have any long-term clinical implications. The increased operative time, although clinically relevant, does not appear to be associated with an increase in complications.