Comparison of the clinical and radiological outcomes of three minimally invasive techniques for total knee replacement at two years

Comparisons of the Efficacy and Safety of Total Knee Arthroplasty by Different Surgical Approaches: A Systematic Review and Network Meta-analysis

The purpose of this network meta‐analysis was to investigate the efficacy and safety of total knee arthroplasty (TKA) considering seven different surgical approaches. Four databases (PubMed, Cochrane Library, EMBASE, Web of Science) were searched for clinical randomized controlled trials (RCTs) involving TKA with different surgical approaches. STATA 14.0 was used to construct network maps and publication bias graphs and conduct inconsistency tests, network meta‐analyses, and surface under the cumulative ranking (SUCRA) calculations. A total of 51 RCTs involving 4061 patients and 4179 knees from 18 countries were included. Among the seven surgical approaches, the midvastus approach (MV) was the top choice to reduce tourniquet use time, the subvastus approach (SV) had the shortest operation time, the mini‐midvastus approach (Mini‐SV) was associated with the least amount of time to achieve straight leg raise (SLR) after surgery, the mini‐medial parapatellar approach (Mini‐MP) reduced postoperative pain effects, and the medial parapatellar approach (MP) was the best approach to improve range of motion (ROM). Excluding the quadriceps‐sparing approach (QS), which was not compared, the use of the mini‐midvastus (Mini‐MV) may shorten the hospital stay. There were no significant differences in blood loss, postoperative complications, American Knee Society Score (AKSS) objective, or AKSS functional between the seven surgical approaches (P > 0.05).

Comparison of minimally invasive approaches and standard median parapatellar approach for total knee arthroplasty: A systematic review and network meta-analysis of randomized controlled trials

BACKGROUND: Minimally invasive total knee arthroplasty (TKA) has been actively advertised by the orthopedic industry. The purpose of this network meta-analysis was to comprehensively compare the effectiveness of four minimally invasive surgery (MIS) approaches and the medial parapatellar (MPP) approach to improve the American Knee Society Score (KSS) in primary TKA. MATERIALS AND METHODS: Studies were comprehensively searched on PubMed, Embase, Cochrane Library (CENTRAL), Web of Science and Science Direct up to June 2018 with a major focus on the outcome of KSS. Risk of bias was assessed using the Cochrane risk of bias tool. Quality assessment was performed using the GRADE system. Both pair-wise and network meta-analyses are calculated to comprehensively compare the effectiveness of four MIS and TKA approaches. RESULTS: Eleven trials with 1025 knees undergoing TKA were included. Our analysis showed that both MPP and MIS approaches provided improvement in terms of short-term (four-eight weeks) total, objective and functional KSS. The network-meta analysis revealed that MIS approaches showed a trend towards superior KSS improvement over standard MPP approaches. However, statistical advantages were only observed in the mini-MPP group for functional KSS compared to the conventional MPP and quadriceps-sparing (QS) groups. CONCLUSIONS: Evidence shows that MIS TKA approaches are effective alternatives to MPP approaches. However, orthopedic surgeons should be cautiously optimistic about minimally invasive TKA in terms of KSS improvement.

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.

Quadriceps muscle group function and after total knee arthroplasty-asystematic narrative update

BACKGROUND

This article systematically summarizes the present evidences, published in the last 20 years, regarding the pre- and post-operative factors, which may influence recovery of the function of the quadriceps muscle group following total knee arthroplasty (TKA). We following the PRISMA methodology, including meta-analyses and high-level evidence studies (prospective trials, and, when unavailable, retrospective studies).

SOURCES OF DATA

Pubmed and Cochrane databases: 582 articles were identified and 54 of them were selected.

AREAS OF AGREEMENT

Tourniquets inflated at high pressure exert a detrimental effect on the quadriceps muscle group. Faster quadriceps recovery takes place using mini-invasive approaches, an eight-week rehabilitation period including balance training and the use of nutraceuticals.

AREAS OF DISAGREEMENT

Pre-habilitation and pre-operative factors, analgesic methods and different TKA implants.

GROWING POINTS AND AREAS TIMELY FOR DEVELOPING RESEARCH

Telerehabilitation seems a cost-effective tool for rehabilitation after TKA. Patients' optimization protocols before TKA should include standardized nutraceuticals intake.

No differences in mid- to long-term outcomes of computer-assisted navigation versus conventional total knee arthroplasty

PURPOSE

Accurate implant position in total knee arthroplasty (TKA) can potentially lead to better long-term functional outcomes and implant survival. Recent studies on whether better clinical results could be obtained from computer-navigated or conventional TKA were inconclusive. In addition, recent reviews only included short-term follow-up studies without performing quantitative mid- to long-term follow-up analysis. Thus, the purpose of the present study was to perform a meta-analysis comparing mid- to long-term clinical outcomes (such as knee scoring and functional results) and radiological outcomes (such as normal alignment of the limb axis or component) between computer-navigated TKA and conventional TKA to determine which method of TKA could obtain better clinical and radiological results.

METHODS

MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science, and SCOPUS electronic databases were searched for relevant articles published through August 2018 that compared outcomes of computer-navigated TKA and conventional TKA. Data search, extraction, analysis, and quality assessment were performed according to the Cochrane Collaboration guidelines. Clinical and radiological outcomes of both techniques were evaluated using various outcome measures.

RESULTS

Seven randomized controlled trials were included. Based on Knee Society Scores, the Western Ontario and McMaster Universities Osteoarthritis Index, pain, and range of motion, there were no significant differences in clinical outcomes between the two techniques. Based on outliers from the normal axis, outliers of femoral components in the coronal plane, and outliers of tibial components in the coronal plane, radiologic outcomes showed no significant differences between the two techniques either.

CONCLUSIONS

The present study revealed that there were no significant differences in clinical or radiological outcomes between computer-navigated TKA and conventional TKA. It remains unclear which TKA technique yields better results in terms of mid- to long-term clinical and radiological outcomes.

LEVEL OF EVIDENCE

I.

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.

Better outcomes after mini-subvastus approach for primary total knee arthroplasty: a Bayesian network meta-analysis

Introduction

Alternatives to the classical medial parapatellar (MPP) approach for total knee arthroplasty (TKA) include the mini-medial parapatellar (MMPP), mini-subvastus (MSV), mini-midvastus (MMV) and quadriceps-sparing (QS) approaches. The best approach has been not fully clarified. The purpose of the present study was to conduct a Bayesian network meta-analysis comparing these approaches.

Materials and methods

The present analysis was carried out according to the PRISMA extension statement for reporting systematic reviews incorporating network meta-analyses of healthcare interventions. The databases search was performed in October 2019. All clinical trials comparing two or more approaches for primary TKA were considered for inclusion. The baseline comparability was evaluated through the analysis of variance (ANOVA) test. The statistical analysis was performed through the STATA software/MP. A Bayesian hierarchical random-effects model analysis was adopted in all the comparisons.

Results

Data from 52 articles (4533 patients) were collected. The mean follow-up was 20.38 months. With regard to diagnosis, gender, age and BMI, adequate baseline comparability was detected. The MSV approach ranked better concerning clinical scores (the lowest visual analogic scale, the higher KSS and KSFS) and functional outcomes (the shortest straight leg raise, the greatest degree of flexion and range of motion). Concerning perioperative data, the MSV evidenced the shortest hospital stay, while the MPP the shortest surgical duration and lowest estimated blood loss.

Conclusion

According to the main findings of the present study, the mini-subvastus approach for total knee arthroplasty demonstrated superior overall compared to the other approaches. Orthopaedic surgeons should consider this approach in the light of the evidence and limitations of this Bayesian network meta-analysis.

Quadriceps-sparing versus traditional medial parapatellar approaches for total knee arthroplasty: a meta-analysis

Background

There is still controversy regarding whether Quadriceps-sparing (QS) approach for total knee arthroplasty (TKA) lead to better earlier recovery as well as compromising low limb alignment and prosthesis position compared with conventional medial parapatellar (MP) approach. To overcome the shortcomings and inaccuracies of single studies, the clinical outcomes and radiographic assessments of QS approach and MP approach were evaluated through meta-analysis.

Methods

We performed this meta-analysis according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines. A literature search was conducted in the PubMed, EMBase, Cochrane Collaboration Library and Web of Science databases. Our search strategy followed the requirements of the Cochrane Library Handbook. The study selection, data extraction and assessment of methodological quality were independently completed by four authors. And subgroup analysis and publication bias were also performed in the study.

Results

Eight prospective randomized controlled trials (RCTs) and eight retrospective studies were identified. Overall meta-analysis and subgroup meta-analysis of RCTs identified the QS approach mainly was associated with increased Knee Society function score beyond 24 months postoperatively (weighted mean difference [WMD] 1.78, P = 0.0004) (WMD 1.86, P = 0.0002), and improved range of motion 1–2 weeks postoperatively (WMD 5.84, P < 0.00001) (WMD 4.87, P = 0.002). Besides, lower visual analogue scale on postoperative day 1 (WMD -0.91, P = 0.02), shorter hospital stay (WMD -0.88, P = 0.02) and shorter incision (extension) (WMD -4.62, P < 0.00001) were indicated in overall meta-analysis. However, surgical and tourniquet time was significantly longer in QS group by both overall and subgroup meta-analysis.

Conclusions

QS approach may accelerate early recovery without increasing the risk of malalignment of low limb and malposition of prosthesis.

Lateral parapatellar and subvastus approaches are superior to the medial parapatellar approach in terms of soft tissue perfusion

PURPOSE

The arthrotomy techniques of knee surgery may cause varying degrees of disruption to the tissue blood supply. The aim of this study was to investigate the effects of the medial parapatellar (MPPa), midvastus (MVa), subvastus (SVa) and lateral parapatellar (LPPa) approaches on regional tissue perfusion of the knee.

METHODS

In this experimental study, a total of 28 female rabbits were applied with four different arthrotomy techniques as Group MPPa, Group MVa, Group SVa and Group LPPa. The blood supply of the tissue around the knee was examined by scintigraphic imaging including the perfusion reserve and T _max, and biochemical alteration of the oxidative stress parameters including malondialdehyde (MDA), fluorescent oxidation products (FlOPs), and histopathological findings were evaluated on tissue samples after 3 weeks.

RESULTS

The perfusion reserve was increased in all four groups compared to the healthy, contralateral knees. In the Group LPPa, the vascularity was significantly increased compared to the Group MPPa (p = 0.006). In the examination of biochemical parameters, the increase in MDA levels was statistically significant in the Group MPPa compared with the Group LPPa (p = 0.004), and in the Group MVa compared with the Group LPPa (p = 0.006). The increase in the value of MDA levels was striking in the Group MPPa and Group MVa compared with the control group (p = 0.004, p = 0.004, respectively). The increase in another oxidative stress parameter, the tissue FlOPs levels, was statistically significant in the Group MPPa compared with the control group (p = 0.035).

CONCLUSION

The LPPa and SVa caused less oxidative stress and less disruption of the muscle blood supply, in biochemical and scintigraphic parameters, compared to the MPPa and MVa. Therefore, in clinical practice, the SVa is preferable to the MPPa and MVa in total knee arthroplasty and the LPPa should be preferred more frequently in selected cases with critical soft tissue viability.

Minimally invasive versus conventional approaches in total knee replacement/arthroplasty: A review of the literature

Background

Life expectancy lengthening and aging of population resulted in dramatically increase of patients with osteoarthritis. Total knee arthroplasty is widely used as the gold standard in order to relieve pain, correct deformity and restore function. A contemporary and controversial topic, is that of minimally invasive surgery for TKA. The minimally invasive approaches are based on the concept that they don't violate the extensor mechanism, resulting in earlier functional recovery, shorter hospital stay and enhanced patients' overall satisfaction. The most commonly used MIS approaches in TKA are the subvastus, midvastus and the quadriceps sparing. There is a debate regarding the efficacy and safety of these methods.

Objective

In this article we will review the current literature (randomized controlled trials and systematic reviews/meta-analyses) on MIS compared to traditional approach and analyse their clinical safety, efficacy and long-term results.

Design

Comparison of well-designed studies have tried to demonstrate the advantages/disadvantages, the clinical results and the complications of the MIS approaches compared to the MPP approach.

Results

MIS approaches seem to provide advantages in the immediate post-operative period accompanied by increased reports of complications. Consequently, further investigation based on large well-designed studies with long-term results are warranted to further clarify MIS effectiveness/safety.

Comparison of Quadriceps-Sparing and Medial Parapatellar Approaches in Total Knee Arthroplasty: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND

The quadriceps-sparing (QS) technique for total knee arthroplasty (TKA) was introduced to improve outcomes associated with the medial parapatellar (MP) approach. There is no clear consensus on what advantages, if any, QS provides.

METHODS

We performed a meta-analysis of randomized controlled trials (RCTs) comparing the QS and MP techniques. PubMed, Ovid, and Scopus were assessed for relevant literature. Long-term (primary) outcomes and short-term (secondary) outcomes from 8 RCTs (579 TKAs) were analyzed using OpenMetaAnalyst (2016).

RESULTS

The QS approach did not demonstrate clinically significant advantages, but was associated with statistically and clinically significant increases in the primary outcomes of femoral (odds ratio [OR] 4.92, P = .005), tibial (OR 4.34, P = .01), and mechanical axis outliers (OR 4.77, P = .004). Secondary outcome assessments demonstrated increased surgical (mean differences [MD] 19.54, P < .001) and tourniquet time (MD 23.30, P < .001) for QS. Although statistically significant advantages for QS were identified in Knee Society Function scores at 1.5-3 months (MD 2.31, P = .004) and 2 years (MD 1.86, P < .001), these were not clinically significant (fell below the 6-point minimal clinically important difference).

CONCLUSION

The QS approach to TKA fails to demonstrate clinically significant advantages, but shows increased malalignment. This increased incidence of implant malalignment may predispose QS patients to early prosthesis failure. Because the QS approach may increases the risk of malalignment while providing no clear benefit compared to MP, we recommend against the routine use of the QS TKA approach.

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.

A randomized controlled clinical and radiological trial about outcomes of navigation-assisted TKA compared to conventional TKA: long-term follow-up

PURPOSE

Well balanced knees with good alignment are essential for a well-functioning TKA with long survival of its implants. This prospective randomized study comparing navigation-assisted TKA and conventional TKA reported the clinical and radiological outcomes at a follow-up of 9 years. The purpose of this study was to compare the clinical and radiological outcomes for patients who underwent navigation-assisted TKA or conventional TKA after long-term follow-up.

METHODS

A total of 80 patients (88 knees) were available for physical and radiological examination 9 years after TKA. Clinical outcomes were evaluated using HSS, WOMAC, and KS function and pain scores. And radiological outcomes of the component loosening and its survivorship during 9-year follow-up were also evaluated.

RESULTS

There were no significant differences in the field of clinical outcomes between the two groups. In terms of radiological outcomes, the navigation group had fewer alignment outliers (7.3 vs 20 %, p = 0.006). Although the clinical outcomes showed no differences between the two groups, the survival rate was slightly better in the navigation group than in the conventional group without statistical significance (best-case scenario 100 vs 95.3 %, n.s., worst-case scenario 95.6 vs 88.4 %, n.s.).

CONCLUSION

Navigation-assisted TKA produced better alignment outcomes and better survival rates than conventional instruments although some of the differences were not statistically significant.

LEVEL OF EVIDENCE

I.

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.

Computer-assisted total knee arthroplasty using mini midvastus or medial parapatellar approach technique: A prospective, randomized, international multicentre trial

Background

Despite the growing evidence in the literature there is still a lack of consensus regarding the use of minimally invasive surgical technique (MIS) in total knee arthroplasty (TKA).

Methods

A prospective, randomized, international multicentre trial including 69 patients was performed to compare computer-assisted TKA (CAS-TKA) using either mini-midvastus (MIS group) or standard medial parapatellar approach (conventional group).

Patients from 3 centers (Maastricht, Zwickau, Adelaide) with end-stage osteoarthritis of the knee were randomized to either an MIS group with dedicated instrumentation or a conventional group to receive cruciate retaining CAS-TKA without patella resurfacing. The primary outcome was to compare post operative pain and range of motion (ROM). The secondary outcome was to measure the duration of surgery, blood loss, chair rise test, quadriceps strength, anterior knee pain, Knee Society Score (KSS),WOMAC scores, mechanical leg axis and component alignment.

Results

Patients in the MIS group (3.97 ± 2.16) had significant more pain at 2 weeks than patients in the conventional group (2.77 ± 1.43) p = 0.003. There was no significant difference in any of the other primary outcome parameters. Surgery time was significantly longer (p < 0.001) and there were significantly higher blood loss (p = 0.002) in the MIS group as compared to the conventional group. The difference of the mean mechanical leg alignment between the groups was not statistically significant (–0.43° (95 % CI –1.50 – 0.64); p = 0.43).

There was no significant difference of component alignment between the two surgical groups with respect to flexion/extension (p = 0.269), varus/valgus (p = 0.653) or rotational alignment (p = 0.485) of the femur component and varus valgus alignment (p = 0.778) or posterior slope (p = 0.164) of the tibial component.

Conclusion

There was no advantage of the MIS approach compared to a conventional approach CAS-TKA in any of the primary outcome measurements assessed, however the MIS approach was associated with longer surgical time and greater blood loss. MIS-TKA in combination with computer navigation is safe in terms of implant positioning.

Trial registration number

ClinicalTrials.gov NCT02625311 8 December 2015

Comparison of the quadriceps-sparing and subvastus approaches versus the standard parapatellar approach in total knee arthroplasty: a meta-analysis of randomized controlled trials

Background

The quadriceps-sparing and subvastus approaches are two of the most commonly used minimally-invasive approaches in total knee arthroplasty (TKA). However, the conclusion among studies still remains controversial. The purpose of this meta-analysis was to compare the clinical efficacy of the subvastus and quadriceps-sparing approaches with the standard parapatellar approach in TKA.

Methods

Randomized controlled trials (RCTs) comparing the quadriceps-sparing or subvastus approach with the standard parapatellar approach was identified in the databases of PubMed, the Cochrane library, EMBASE and Web of Science up to July 2014. Two authors extracted the following data: the basic characteristics of patients, the methodological quality and clinical outcomes from the included RCTs independently. RevMan 5.2.7 software was used for meta-analysis.

Results

A total of 19 RCTs (1578 patients) were included for meta-analysis. The results suggested that the quadriceps-sparing approach showed better outcomes in knee society score (KSS) and visual analog score (VAS), but this approach required a longer operative time than the standard parapatellar approach. There were no differences in total complications, wound infection, deep vein thrombosis, blood loss and hospital stay between the quadriceps-sparing and standard approaches. The subvastus approach showed better outcomes in VAS, knee range of motion (ROM), straight leg raise and lateral retinacular release than the standard parapatellar approach. There were no differences in KSS, total complication, wound infection, deep vein thrombosis, blood loss and hospital stay between the quadriceps-sparing and standard approaches.

Conclusions

The current evidence showed that, when compared with the standard parapatellar approach, the quadriceps-sparing approach was associated with better outcomes in KSS and VAS but required a longer operative time, and the subvastus approach was associated with better outcomes in VAS, ROM, straight leg raise and lateral retinacular release.

Are There Any Clinical and Radiographic Differences Between Quadriceps-sparing and Mini-medial Parapatellar Approaches in Total Knee Arthroplasty After a Minimum 5 Years of Follow-up?

BACKGROUND

Although the early clinical outcomes of total knee arthroplasty (TKA) using minimally invasive surgery techniques have been widely described, data on the mid- to long-term outcomes are limited. We designed a retrospective study to compare the two most common TKA techniques - The modified quadriceps-sparing (m-QS) approach and the mini-medial parapatellar (MMP) approach - In terms of the clinical and radiographic parameters, over a minimum follow-up period of 5 years.

METHODS

The m-QS approach was used in 31 knees and the MMP approach, in 36 knees. Knees in both groups were compared for component position and alignment, knee alignment, length of the skin incision, range of motion, Visual Analog Scale score, muscle torques, Knee Society Score, Western Ontario and McMaster Universities Osteoarthritis Index, and number of complications.

RESULTS

There were no major intergroup differences in any of the clinical and radiographic outcomes assessed at the final follow-up examination.

CONCLUSIONS

On the basis of numbers studied, the m-QS group, which requires more technique, showed equivalent results with the MMP group in the postoperative 5 years. Preservation of the extensor mechanism in the m-QS approach could not ensure any improvement in the clinical outcomes during the mid-term follow-up duration.

Optimal patellar alignment with minimally invasive approaches in total knee arthroplasty after a minimum five year follow-up

PURPOSE

Patellofemoral syndrome is still a common complication after total knee arthroplasty (TKA). However, the effects of specific surgical approaches on patellar tracking and alignment remain incompletely understood. In this study, we compared patellar alignment in patients who underwent TKA via three different techniques.

METHODS

A total of 96 patients who completed a minimum follow-up of five years were involved in three groups: 30 patients were treated with the traditional medial parapatellar approach (MPP group), 35 patients were treated with the mini-medial parapatellar approach (MMP group) and 31 were treated with a quadriceps-sparing approach (QS group). Radiographic data for patellar alignment and clinical results were compared.

RESULTS

Patellar tilt and patellar displacement at the final follow-up evaluation differed significantly among the three groups [P < 0.01, analysis of variance (ANOVA)]. The MMP and QS groups exhibited more proper patellar alignment than the MPP group. The clinical results did not differ significantly among the groups (P > 0.05, ANOVA). In addition, there were no correlations between postoperative patellar alignment and clinical scores.

CONCLUSIONS

The results of this study indicate that TKA performed using minimally invasive approaches yields superior patellar alignment compared to the traditional MPP approach.

Minimum 5-year Follow-up Results of Minimally Invasive Total Knee Arthroplasty Using Mini-Keel Modular Tibial Implant

Purpose

To evaluate the minimum 5-year mid-term clinical and radiological results of minimally invasive surgery total knee arthroplasty (MIS-TKA) using a mini-keel modular tibia component.

Materials and Methods

We retrospectively evaluated 254 patients (361 cases) who underwent MIS-TKA between 2005 and 2006. The latest clinical and radiological assessments were done in 168 cases that had been followed on an outpatient basis for more than 5 postoperative years. Clinical results were assessed using the Hospital for Special Surgery (HSS) score and Knee Society score. Radiological evaluation included measurements of knee alignment.

Results

The average postoperative knee range of motion and HSS score were 134.3°±12.4° and 92.7°±7.0°, respectively. The average postoperative femorotibial angle and tibial component alignment angle were 5.2°±1.7° valgus and 90.2°±1.6°, respectively. The average tibial component posterior inclination was 4.8°±2.1°. The percentage of cases with tibial component alignment angle of 90°±3° was 96.1%, and that with the femorotibial angle of 6°±3° valgus was 94.0%. Radiolucent lines were observed in 20 cases (12.0%): around the femur, tibia, and patella in 14 cases, 10 cases, and 1 case, respectively. However, they were less than 2 mm and non-progressive in all cases. The survival rate was 99.4% and there was no implant-related revision.

Conclusions

MIS-TKA using a mini-keel modular tibial plate showed satisfactory results, a high survival rate, and excellent clinical and radiological results in the mid-term follow-up.